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IOBC-WPRS Bulletin Vol. 78, 2012

 

IOBC-WPRS Bulletin Vol. 78, 2012

Working Group "Biological Control of Fungal and Bacterial Plant Pathogens".
Proceedings of the meeting at Graz (Austria), 07 - 10 June, 2010.
Edited by: Ilaria Pertot, Yigal Elad, Cesare Gessler, A. Cini.
ISBN 978-92-9067-256-2 [XXII + 400 pp.]

 

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Changing management practices and the environment:
impact on soilborne pathogens and biological control

David M. Weller, Timothy C. Paulitz, Dmitri V. Mavrodi, Olga V. Mavrodi, James A. Parejko, Linda S. Thomashow

Abstract: Climate change is a regional, national and global environmental policy issue that
undoubtedly will be a major economic force for the rest of the 21st century and beyond as nations
develop alternatives to traditional fossil fuels to drive and sustain their economic growth. This
paper discusses how changes in regional and local environmental conditions, predicted to occur
as a result of climate change, may impact crop management practices, diseases and their
biocontrol agents. This paper focuses on the Pacific Northwest, located in the Northwest corner
of the USA. More specifically, it focuses on wheat production and soilborne diseases in central
and eastern Washington State and well-studied Pseudomonas spp. that suppress these diseases.
What is currently known about the impact of environment and management practices on
populations of indigenous Pseudomonas spp. that provide natural biocontrol can be used to
predict how climate change could impact the biogeography and disease suppressive activity of
these biocontrol agents.

3-9

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Climate change and plant health - increasing importance of biocontrol options
for risk management of quarantine pests

Sylvia Blümel

Abstract: Plant health is directly or indirectly influenced by climatic factors. The potential
effects of climate change together with the increasing globalisation of trade with plants and plant
products will facilitate the introduction, natural invasion and spread of non-endemic phytosanitary
plant pathogen species of economic importance to previously unaffected agricultural,
horticultural or forestry production areas. Whereas the introduction of quarantine pests can partly
be prevented by inspections and monitoring surveys, risk management strategies in case of their
establishment and spread under changed climatic conditions are mainly missing. In this context
future research needs on climate change effects on plant pathogens and biological control which
have been identified are presented and discussed.

11-14

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Climate change effect on plant – pathogen – beneficial microorganisms interaction
in high humidity-promoted tomato diseases

Hananel Ben Kalifa, Dalia Rav David, Menahem Borenshtein, Ran Shulchany, Yigal Elad

Abstract: Climate change refers to changes in the means and/or variabilities of climate
parameters. Plant pathogens have a range of environmental conditions which allows them to
survive and cause disease. Environmental changes might cause alterations in distribution,
survival and plant-pathogen interactions; these changes can increase or decrease epidemical
events. The suppressive effect of beneficial organisms may also be affected by environmental
conditions. Two humidity promoted polycyclic diseases were studied: i. late blight (Phytophthora
infestans) – a fast developing and destructive disease in tomato and potato plants. A critical factor
for disease epidemic occurrence is 6-8 hours of wetness which allows penetration into the plant
tissue; ii. grey mould (Botrytis cinerea) – infects many crops including tomato and proliferates at
high humidity, few hours of wetness are a prerequisite for infection. Tomato plants inoculated
with P. infestans with wetness duration of 4, 6, 8, 12 and 24 hours showed decrease in disease
frequency and severity under 8 and 12h wetness as compared with 24h. B. cinerea infection
severity was different between 4 and 10h wetness duration. Spraying the plants with two yeast,
three bacterium isolates and Trichoderma followed inoculation with P. infestans under wetness
durations of 8 and 24h, revealed an effect of wetness duration on biocontrol activity; 24h wetness
duration less disease control was observed. When treating with the microorganisma at pre- and
post-inoculation, the same disease suppression was obtained for 8 and 24h wetting periods. Two
of the BCAs decrease sporangia formation. No interaction in grey mould supression was
observed between biocontrol agents and wetness duration. It seems that environmental conditions
which decrease late blight intensity allow better activity of the introduced biocontrol agents.
Climate change is expected to affect rain quantity and frequency and as a result the duration of
wetness may be affected. This in turn, in some cases as demonstrated in the present work, may
affect the ability of beneficial organisms to suppress diseases.

15-18

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Is the climate really changing in favour of biopesticides?
Willem Ravensberg

Abstract: Many factors influence the adoption of biopesticides in the marketplace. Some are
hampering biopesticide, other favour them. Changes in legislation, and in political, cultural and
social perceptions determine the demand for sustainable crop protection agents. Research and
technological discoveries create new possibilities for development of better products.
Globalisation opens new markets and offers potential usages, but also creates more problems
such as invasive pests and diseases. Trends in the biopesticide industry stimulate new products
and markets. The current macro-environmental trends support the assumption that demand for
alternative crop protection products will grow rapidly to replace conventional chemical
pesticides.

19-22

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Effect of temperature on microbial biocontrol agents of plant diseases
Ilaria Pertot, Dario Angeli, Ohad Agra, Yigal Elad

Abstract only

23

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Pantoea agglomerans 48b/90 suppresses bacterial plant pathogens
in a wide temperature range in planta

Ulrike Sammer, Dieter Spiteller, Beate Völksch

Abstract only

24

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Climate change, biocontrol and integrated plant disease management: Problems and
perspectives of biocontrol under Mediterranean conditions

Blanca B. Landa, Juan A. Navas-Cortés

Abstract only

25-26

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Impact of elevated atmospheric O3 on the actinobacterial community structure
and function in the rhizosphere of European beech (Fagus sylvatica L.)

Felix Haesler, Alexandra Hagn, Marion Engel, Jean Charles Munch, Michael Schloter

Abstract only

27

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Priming Vitis vinifera L. with plant growth promoting Burkholderia phytofirmans
strain PsJN enhances its acclimation to low non-freezing temperatures

Andreas Theocharis, Sophie Bordiec, Olivier Fernandez, Sandra Paquis, Sandrine Dhondt-Cordelier, Fabienne Baillieul, Christophe Clément, Essaid Ait Barka

Abstract only

28

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Antagonistic endophytes from mistletoes as bio-resource to control plant
as well as clean room pathogens

Gabriele Berg, Kathrin Hartenberger, Stefan Liebminger‚ Christin Zachow

Abstract: Viscum album is a hemiparasitic shrub on a wide range of wood species. The bacterial
and fungal communities of Viscum album subsp. album and three different host species (Malus
domestica, Juglans nigra and Acer tataricum) were analysed by cultivation dependent methods.
Endophytes were isolated from leaves and seeds of Viscum album as well as from branches of the
host trees on five different growing media. The isolated endophytes were screened for
antagonistic effects i) against plant pathogens (Alternaria alternata, Botrytis cinerea,
Phytophthora infestans, and Sclerotinia sclerotiorum), and ii) against clean room inhabitants or
pathogens (gram- positive bacteria: Staphylococcus epidermidis, Propionobacterium acnes,
Paenibacillus polymyxa, Geobacillus stearothermophilus, Bacillus pumilus; gram-negative
bacteria: Stenotrophomonas maltophilia, Escherichia coli, Pseudomonas aeruginosa; fungi:
Verticillium dahliae, Aspergillus niger, Candida albicans) by dual culture assay. Beside the high
proportion of antagonistic isolates against both groups in general, we found similarities but also
clear differences between parasite and host. Mistletoes, especially the seeds, contained a higher
antagonistic potential than the host plants. Plant-associated endophytic microorganisms from
parasitic plants are an interesting bio-resource to control plant pathogens but also clean room
inhabitants/pathogens.

29-32

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Screening criteria for the development of commercial products for biocontrol of plant pathogens
Jürgen Köhl, Bernard Blum, Philippe Nicot, Michelina Ruocco

Abstract: Antagonists for use in commercial biocontrol products have to fulfil many different
requirements. Besides being active control agents against the specific targeted plant pathogens,
they must be safe and cost effective. The development of new biocontrol products starts with
screening programs including hundreds or thousands of candidates. For commercial use,
important criteria are market size, efficacy, ecological characteristics, production costs, safety,
environmental risks and protection of intellectual property rights. A stepwise screening
considering these very different aspects is proposed.

35-37

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The use of molecular tools to unravel the complex interaction of biological control strains,
pathogens and indigenous microbial communities

Simone Dealtry, Guo-Chun Ding, Nicole Weinert, Yvette Piceno, Gary L. Andersen, Michael Schloter, Gabriele Berg, Leda Mendonça-Hagler, Rita Grosch, Kornelia Smalla

Abstract only

38

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Endophytes of grapevine as potential control agents against fungal vine diseases
Martin Kirchmair, Sabine Trenkwalder, Lars Huber, Sigrid Neuhauser

Abstract: Grapevine trunk diseases like esca are difficult to control and cause significant
economic loss in vine growing areas all over the world. The causal organisms are xylem
inhabiting, pathogenic fungi sharing habitat with other endophytic microorganisms. Xylem sap of
twigs of healthy and esca affected vines was plated onto nutrient media. The isolated endophytes
were identified morphologically and by DNA sequence analysis. Dominant yeast endophytes
were Aureobasidium pullulans, Cryptococcus magnus and Rhodotorula cf. glutinis. The most
abundant endophytic bacteria belonged to the genera Curtobacterium, Frigoribacterium,
Pantoea, Pseudomonas and Bacillus. The antagonistic potential of selected endophytes against
grapevine pathogenic fungi (Phomopsis viticola, Phaeomoniella chlamydospora, Cylindrocarpon
sp., Roesleria subterranea) was evaluated in vitro. Isolated yeasts (e.g. Aureobasidium pullulans)
and bacteria (esp. Gammaproteobacteria) considerably inhibited the growth of grapevine
pathogenic fungi. To test the effect on plant growth cress tests with the culture-supernatant of
endophytic yeasts cultures were conducted. Sporobolomyces roseus, Rhodotorula pinicola and an
unknown Cryptococcus species promoted the root growth of cress seedlings. These results point
towards endophytes playing a critical role as plant growth promoters and in the defense against
plant pathogens. Endophytes have the potential to play a future key role as biocontrol agents and
biofertilizers.

39-43

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Biological control of Rhizoctonia solani by stimulation
of naturally present antagonistic Lysobacter spp.

Joeke Postma, Mirjam Schilder, Els Nijhuis

Abstract: Disease suppressive soils towards Rhizoctonia solani AG2 were found to comprise
three closely related antagonistic species, i.e. Lysobacter antibioticus, L. capsici, and
L. gummosus. Isolates of these species showed strong in vitro inhibition of several plant
pathogens. The current research focuses on the ecology of these Lysobacter species with the aim
to stimulate their natural population in soil and as a consequence enhance disease
suppressiveness of soil systems. Recent results showed that chitin, chitosan, yeast cells and
mushroom powder stimulated Rhizoctonia disease suppression in a bioassay with sugar beet.
Meanwhile, Lysobacter populations detected by QPCR were about 5 to 20 times higher than in
the control soil. Other organic compounds such as compost or cellulose were not effective. With
these results we finally aim to develop a more sustainable growing system, benefitting from the
microflora naturally present in soil.

45-47

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Biocontrol of rice sheath blight by Trichoderma: selection of promising BCAs
and development of strain specific monitoring tools

Shahram Naeimi, Sándor Kocsubé, Zsuzsanna Antal, Seyed Mahmood Okhovvat, Mohammad Javan-Nikkhah, Csaba Vágvölgyi, László Kredics

Abstract: A total of 202 Trichoderma strains were isolated from the soil and rice phyllosphere in
paddy fields at 45 locations throughout the Mazandaran province, Northern Iran. T. harzianum
and T. virens proved to be the most frequent species in these habitats. Based on the results of in
vitro antagonism tests and glasshouse trials, strains with biocontrol potential against the rice
sheath blight pathogen Rhizoctonia solani were selected. UP-PCR based SCAR markers were
developed for the specific detection and monitoring of T. harzianum AS12-2, the most promising
biocontrol strain.

49-53

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Effect of nutrient amendment and osmoadaptation in blossom colonization
of pome fruit trees and efficacy of biocontrol of Ervinia amylovora

Jordi Cabrefiga, Anna Bonaterra, Jesus Frances and Emilio Montesinos

Abstract: The efficacy of Pseudomonas fluorescens EPS62e in the biocontrol of Erwinia
amylovora, the causal agent of fire blight disease, depends on the colonization of plant surfaces.
A procedure to increase cell survival in the phyllosphere was developed consisting of nutrient
amendment, osmoadaptation and their combination. Glycine and Tween80 were selected as
appropriate substrates to add as nutrient complements in the formulation of EPS62e, both
nutrients are used by EPS62e and not by E. amylovora strains. Colonization and survival of
EPS62e on detached flowers studies were performed in controlled environmental conditions. At
high RH population levels of EPS62e remains stable and were not affected by the treatments.
Whereas at low RH, population levels of EPS62e fall down and an enhancement of their survival
in the nutrient amended and osmoadapted was observed. Population dynamics of EPS62e in field
conditions were assessed by real-time PCR and CFU-counting methods. Values obtained by both
methods were quite correlated and population levels of EPS62e decreased to steady-state and
reach values around 106 CFU/blossom in the standard application and were significantly higher,
around 107 CFU/blossom, in nutrient amended also in osmoadapted treatment and especially in
the combined treatment. Finally, the efficacy in the control of fire blight infections under field
conditions was also assessed and the best treatment was the combination of nutrient amendment
with the osmoadaptation.

55-57

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Cell-to-cell communication controls biocontrol activites in members
of the Burkholderia cepacia complex (Bcc)

Silvia Schmidt, Judith F. Blom, Jakob Pernthaler, Gabriele Berg, Eshwar Mahenthiralingam, Leo Eberl

Abstract only

61

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Novel approaches for biocontrol of crown gall disease
Natalia Dandurishvili, Natela Toklikishvili, Naili Giorgobiani, Marina Tediashvili, Marianna Ovadis, Inessa Khmel, Erno Szegedi, Alexander Vainstein, Leonid Chernin

Abstract only

62

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Distribution of antimicrobial peptide biosynthetic gene markers
in plant-associated Bacillus spp. and relationships with antagonistic activity
against bacterial plant pathogens

Isabel Mora, Jordi Cabrefiga, Emilio Montesinos

Abstract: A large collection of Bacillus isolates obtained from natural samples, including aerial
plant parts, rhizosphere and bare soil in agricultural and land environments from the Northeastern
part of Spain, were characterized for the presence of the antimicrobial peptide
biosynthetic genes srfAA (surfactin), bacA (bacyllisin), fenD (fengycin), bmyB (bacyllomicin),
spaS (subtilin) and ituC (iturin). Most isolates had at least one of the biosynthetic genes and
presented 2-to-4 genes simultaneously. The most frequent genotypes were srfAA bacA bmyB
(15.2%) and srfAA bacA bmyB fenD (14.1%). The analysis of in vitro antagonism against eight
species of plant-pathogenic bacteria indicated that the proportion of highly active antibacterial
strains increased with the number of simultaneous genes per strain.

63-66

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Evaluation of anti-phytoplasma properties of surfactin derived
from Iranian native Bacillus subtilis isolates using Real Time PCR

from Iranian native Bacillus subtilis isolates using Real Time PCR Najmeh Askari, Gholamreza Salehi Jouzani, Matin Mohammadi Pour, Maryam Mousivand, Saeed Abbasalizadeh, Ali Hagh Nazari

Abstract: In the present study, the effect of surfactin derived from Iranian native Bacillus subtilis
isolates has been investigated against phytoplasma Candidatus "Phytoplasma aurantifolia" agent
of lime witches broom disease (WBDL) which causes a considerable loss in lime production in
Iran and other countries in the region of Persian Gulf. For this purpose, eight surfactin producing
isolates were evaluated for quantity of surfactin production by HPLC. Quantitative analysis by
HPLC showed that one strain had the highest surfactin production (650mg/l) and were selected
for surfactin extraction. After optimization of surfactin extraction, it was injected into witches
broom phytoplasma-infected seedlings of lime by using syringe injection. To compare
tetracycline effect with surfactin effect against phytoplasma activity and also to investigate
probable synergistic effect of them, we planned to also treat plants with both mentioned
antibiotics at the same time. Two specific primers pairs were designed for qualitative and
quantitative detection of phytoplasma in infected plants. Real Time PCR conjugated with
Fluorescent SYBR® Green I dye and absolute quantification has been developed for rapid,
sensitive and quantitative analysis to assess surfactin bioactivity against phytoplasma, and also to
determine concentration of phytoplasma in infected seedlings before and after treatment. The
results showed that the combination of surfactin had caused significant reduction of phytoplasma
population in infected plants, and also the combination of surfactin and tetracycline had the
highest toxicity against phytoplasma.

67-71

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Modulation of the lipopeptide pattern secreted by Bacillus subtilis
upon colonization of different plant roots

Marc Ongena, Hélène Cawoy, Maïté Smargiassi, Venant Nihorimbere, Emmanuel Jourdan, Philippe Thonart

Abstract: A lot of environmental factors may modulate the production of antibiotics by plant
beneficial rhizobacteria in general and of lipopeptides by Bacillus in particular. Direct evidence
for an ecological role through the demonstration of an efficient lipopeptide production in situ is
thus requested. This was the first aim of this study achieved by using an optimized HPLCcoupled
electrospray ionization MS that also allowed to compare the cLP profiles secreted by
strain S499 in the rhizosphere of different plants. Analyses of these root extracts revealed both
quantitative and qualitative modifications in the lipopeptide signature, suggesting that the root
exudate content may influence the synthesis of these molecules in a plant-specific manner. The
possible impact of such variations in the cLP profile on the biocontrol potential of the producing
strain is discussed.

73-77

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Insecticidal activity in root-associated, plant-beneficial pseudomonads
Monika Maurhofer, Beat Ruffner, Maria Péchy-Tarr, Christoph Keel

Abstract only

78

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From ‛omics’ to the field: functional genomics and implementation models
of Trichoderma BCAs

Sheridan L. Woo, Michelina Ruocco, Francesco Vinale, Roberta Marra, Stefania Lanzuise, Felice Scala, Matteo Lorito

Abstract only

79

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Volatile secondary metabolites of the biocontrol fungus Trichoderma atroviride:
Profiling by HS-SPME-GC-MS

Norbert Stoppacher, Bernhard Kluger, Susanne Zeilinger, Rudolf Krska, Rainer Schuhmacher

Abstract only

80

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Role of G protein signalling in host sensing of the mycoparasite Trichoderma atroviride
Markus Omann, Sylvia Lehner, Carolina Escobar Rodrìguez, Norbert Stoppacher and Susanne Zeilinger

Abstract: Fungi of the genus Trichoderma are frequently found in soil and associated with dead
organic material but are also able to interact with plants, animals and other fungi. Due to these
manifold lifestyles, a broad spectrum of environmental signals has to be recognized by
Trichoderma and integrated into respective signal transduction pathways. Recent studies revealed
the involvement of G protein signaling in governing processes relevant for the mycoparasitic
interaction of T. atroviride with other fungi and both the Tga3G subunit as well as the Gpr1 G
protein-coupled receptor were shown to be relevant for recognizing the host fungus.

81-82

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Identification of Ampelomyces quisqualis genes involved in the early stage
of mycoparasitism (host recognition) of powdery mildew

Lorenzo Tosi, Massimo Delledonne, Alberto Ferrarini, Cesare Gessler, Monika Maurhofer, Ilaria Pertot

Abstract only

83

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Involvement of ROS in mechanism of action of yeast biocontrol agents
of postharvest diseases

Samir Droby, Dumitru Macrasin, Michael Wisniewski

Abstract only

84

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How to deliver beneficial microbes
Jana Monk, Emily Gerard, Sandra Young, Keith Widdup, Trevor Jackson, Maureen O’Callaghan

Abstract only

87

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Practical use of beneficial rhizosphere bacteria in crop production
Jolanta J. Levenfors, Jamshid Fatehi, Margareta Hökeberg, Mariann Wikström, Ann-Sofie Birch-Jensen, Christopher J. Welch

Abstract only

88

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Experiences in applying Bacillus-based biocontrol agents in Chinese agriculture
Rainer Borriss, Helmut Junge, Xuewen Gao, Qi Wang, Yueqiu He

Abstract: In frame of a Chinese German collaboration project we have performed extended
greenhouse and field trials in several Chinese regions, different in their climate and soil
conditions, to investigate the beneficial effect on crops and vegetables exerted by Bacillus-based
bioformulations. Distinct positive effects were obtained in treatment of maize, potatoes,
vegetables, and ornamentals; however time and dosage of the applied bacterial spores did affect
success of the treatment. Whilst “coating” of maize seeds and potato tubers ruled out as a useful
method, vegetables and cut flowers were most successfully treated during transplanting. The
success of the treatment did depend also from an appropriate concentration of the applied
bacteria. Too high concentrations are useless or harmful. In general, we recommend use of
appropriately diluted Bacillus formulations containing 2.5 to 5x1013 bacterial spores
(corresponding to 1 to 2l Rhizovital®) per ha.

89-93

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All over the plant - Microbial products for enhanced health, fitness and quality
Henry Müller, Markus Verginer, Christin Zachow, Gabriele Berg

Abstract only

94

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Review of factors influencing the success or failure of biocontrol:
technical, industrial and socio-economic perspectives

Philippe C. Nicot, Claude Alabouvette, Marc Bardin, Bernard Blum, Jürgen Köhl, Michelina Ruocco

Abstract: Although their role in plant health management is still quite modest, ever increasing
expectations are placed on biocontrol agents for the complementation or replacement of pesticide
use. Despite decades of research and more than 12,000 scientific papers on biological control of
plant diseases, little more than 14 microbe-based commercial products are presently registered
for use against diseases in the European Union. Through a review of published scientific
literature, economic and market analyses and a survey of 675 farmers in 9 European countries,
difficulties and conditions for success have been identified. The most salient features and future
outlook are presented in terms of scientific/technical aspects, production costs and return on
investment as well as (somewhat unexpected) factors deemed to be most influential on the
evolution of the biocontrol market in the coming decades.

95-98

5.00 €

 

Registration of plant protection products containing micro-organisms in the EU –
changes through the new Regulation 1107/2009

Jacqueline Süß, Rüdiger Hauschild

Abstract: The legal framework and data requirements for the registration of biological plant
protection products in the EU are regulated in Council Directive 91/414. By June 14, 2011 the
Regulation 1107/2009 will apply. The current situation will be presented with an interpretation of
the data requirements and experiences from the regulatory procedure in the EU and different EU
member states. An overview about changes imposed by Regulation (EC) 1107/2009 will be given
with regard to consequences for producers of biological plant protection products.

99-102

5.00 €

 

Mass production of ecologically competent Metarhizium anisopliae spores
for pest management

Verena Niedermayr, Hermann Strasser

Abstract: As new insect pests invade Europe (e.g. Diabrotica or the Siberian grasshopper) and
arthropods, such as FSME- or Borrelia- infested ticks, are to be antagonised, the BIPESCO Team
Innsbruck focused its interest in the product development of fungal biocontrol agents, which can
be applied as foliar spray.
The objective of our study was to compare simple solid state mass production systems for
high yield Metarhizium anisopliae spore production. Methods and tools are syntonized to the
used Metarhizium production strain BIPESCO 5. Mineral and organic carriers are compared in
solid state fermenter systems to enable the production of improved high concentrate spore
formulations. First data on expanded open pored clay granules are presented, which preferentially
stimulates fungal sporulation and spore production after soaking in Sabouraud Dextrose medium.
Grinding of the overgrown mineral carrier showed either no negative effect on the spore vitality
and efficacy, nor was the formulation contaminated with organic impurities.

103-106

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Bacteria controlling cucumber foot and root rot and promoting growth
of cucumber and tomato in salinated soils

Dilfuza Egamberdieva, Gabriele Berg, Vladimir Chebotar, Igor Tikhonovich, Faina Kamilova, Shamil Z. Validov, Ben Lugtenberg

Abstract: Seventeen percent of cucumber plants grown in a Uzbek greenhouse were diseased.
The major cucumber and tomato pathogens of Uzbek agricultural soils were identified as strains
of Fusarium solani. Fifty two beneficial bacteria from collections of our institutes were screened
for their ability to promote growth and/or to control diseases caused by F. solani on cucumber
and tomato plants. The five best strains were used in large scale greenhouse trials. Four out of
five strains significantly controlled cucumber foot and root rot, reducing the percentage of
diseased plants from 54% in the negative control to between 10 and 29% in bacterized plants. All
five strains increased the dry weight, by 29 up to 62%. In two consecutive years all five strains
significantly increased the plant height (by 4 to 15%) as well as the fruit yield (by 12 to 32%).
Tests of plant-beneficial traits suggest that auxin production, antibiosis and competition for
nutrients and niches are mechanisms involved in the observed plant growth stimulation and
biocontrol. The results with tomato were similar. We conclude that many beneficial bacteria
isolated from plants grown on non-salinated soil are perfectly able to promote plant growth and
control plant diseases in salinated soil. In other words, salination caused by a possible future
climate change does not seem to be a threat for the application of presently used plant-beneficial
bacteria. In addition, our results show that the dogma that beneficial strains should be isolated
from the plant and climate on/in which they should be applied is not valid: all our strains were
isolated from plants other than cucumber and came from cold or moderate climates.

107-112

5.00 €

 

Effect of fungal and bacterial bio-control strains and Rhizoctonia solani
on indigenous microbial community in the lettuce rhizosphere

Rita Grosch, Simone Dealtry, Gabriele Berg, Leda Mendonça-Hagler, Kornelia Smalla

Abstract only

113

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Impact of a microbial consortium on the native Pseudomonas
and mycorrhizal community in the rhizosphere of nine different maize genotypes

Andreas von Felten, Carolin Schwer, Olivier Couillerot, Yvan Moënne-Loccoz, Jan Jansa, Geneviève Défago, Monika Maurhofer

Abstract only

114

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Genetic structure and dynamics of the oomycete and fungal communities
colonizing the rhizosphere and the effluents of hydroponic tomato plants
after the introduction of the biocontrol agent Pythium oligandrum

Jessica Vallance, Franck Déniel, Georges Barbier, Patrice Rey

Abstract: In hydroponic cultures, the recycling of drainage water is the main source of
introduction and dissemination of pathogens. The spreading of the biocontrol agent Pythium
oligandrum was investigated in relation to the recirculation of the nutrient solution. The structure
and dynamics of the fungal communities colonizing the effluents and the rhizosphere of
hydroponic tomato plants were also assessed. Real-time PCR and plate counting demonstrated
the persistence of large amounts of the antagonistic oomycete in the rhizosphere throughout the
cropping season (April to September). Despite its abundance on roots, no traces of P. oligandrum
were detected in the different effluents of the soilless system investigated. P. dissotocum
(ubiquitous tomato root minor pathogen) colonized the rhizosphere and the effluents only in
summer. There was a slight reduction of P. dissotocum populations in P. oligandrum-inoculated
root systems. Single-Strand Conformation Polymorphism (SSCP) analyses revealed that the
genetic structure of the fungal communities colonizing the rhizosphere and the effluents was
different and evolved throughout the cropping season. This temporal evolution was independent
from the inoculation and the persistence of the antagonistic oomycete P. oligandrum.

115-118

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The effect of Fusarium oxysporum f. sp. lycopersici and the arbuscular
mycorrhizal fungus Glomus mosseae on tomato (Solanum lycopersicum L.)
intercropped with cucumber (Cucumis sativus L.)

intercropped with cucumber (Cucumis sativus L.) Karin Hage-Ahmed, Vladimir Chobot, Andreas Voglgruber, Franz Hadacek, Siegrid Steinkellner

Abstract: The rhizosphere is known to be a highly dynamic environment, where plant – microbe,
plant – plant and microbe – microbe interactions take place. Components of root exudates can act
as trigger for such interactions. For this work a model system was created consisting of tomato
(Solanum lycopersicum L.), the intercropping partner cucumber (Cucumis sativus L.), the
soilborne tomato pathogen Fusarium oxysporum f.sp. lycopersici (FOL) and the arbuscular
mycorrhizal fungus Glomus mosseae (GM).
Tomato/tomato and tomato/cucumber combinations were grown together in pots and
received the following treatments: FOL, AMF, FOL and AMF in combination, to assess changes
in root exudation, the AMF colonization rate and the FOL infection rate. Furthermore, the
exudates were used for in vitro tests of the initial behaviour and development of FOL and for
analysing the components (e.g. sugars, secondary metabolites) of the exudates. FOL significantly
increased the AMF colonization rate in the FOL and AMF combination compared to the AMF
treatment in tomato/cucumber, whereas for the tomato/tomato combination no such effect could
be detected.

119-122

5.00 €

 

Biology of black rot of grapevine (Guignardia bidwellii) and approaches
towards its control by non-chemical methods

Eckhard Koch, Cornelia I. Ullrich, Bernd Loskill, Michael Maixner, Daniel Molitor, Beate Berkelmann-Löhnertz

Abstract only

125

0.00 €

 

Isolation, characterisation, and identification of antagonistic bacteria
against Fusarium head blight

Sabine Fruehauf, Lukas Sachsperger, Birgit Antlinger, Marc Lemmens, Rudolf Braun, Markus Neureiter

Abstract only

126

0.00 €

 

Control of Plasmodiophora brassicae – literature review and future prospects
Sigrid Neuhauser, Martin Kirchmair

Abstract: Plasmodiophora brassicae Woronin (Plasmodiophorida) is the casual agent of
clubroot, the most important soil-borne disease of cruciferous crops worldwide. Losses were
estimated 10-15% of the annual harvest combining all cruciferous crops including important
food-, industrial- and energy-plants like cole crops, oil seed rape or turnips. The soil-borne and
plant-associated nature of plasmodiophorids as well as their obligate biotrophic multi-stage life
cycle with multiple zoosporic, plasmodial, and resting stages has hampered research on this
group of pathogens. No efficient control strategies are available so far and resistance of most
cultivars has been proven elusive. Different attempts of biological control including soil-borne
and endophytic microorganisms were tested with changing success. A number of potential
biocontrol agents were successfully tested in green house tests, but in field trials the efficacy of
these biocontrol agents varied considerably. Soil properties play a key role for the infection
process and disease development as well as for the success of biological control. Therefore, until
now best results to reduce disease symptoms were obtained with integrated pest management
strategies. One reason why biocontrol agents were not successfully applied until today can be that
the Plasmodiophorida are taxonomically and ecologically far different from “true fungi” or most
other soilborn pathogens. Recent molecular phylogenies place them in the eukaryotic supergroup
“Rhizaria” with a close affiliation to the Cercozoa and Foraminifera. Strategies successful in
controlling fungal diseases cannot necessarily be transferred to organisms of a very different
taxonomic affiliation. Increased knowledge about the taxonomic position and the biology of this
soil-borne pathogen offers potential targets for the future control of the clubroot pathogen.

127-130

5.00 €

 

Powdery mildew on cereals – an increasing problem in triticale cultures
Caterina L. Matasci, Stefan Kellenberger, Fabio Mascher

Abstract: Powdery mildew, caused by the obligate biotrophic ascomycete Blumeria graminis
DC Speer can reduce yield up to 40% without control measures. The first report of the disease on
triticale (x Triticosecale Wittmack) in Switzerland took place in 2001. Since 2005, which marked
the year of the first major epidemic, B. graminis has become established and rapidly adapts to an
increasing number of triticale cultivars. This situation is observed in different European triticale
growing countries. In a situation where the climate change is modifying the national and
international ranges of pests and diseases and where a strong increase in the demand for cereals is
predicted for the future, biological control should focus on selection for resistant cultivars in
combination with adequate culture techniques and, if possible, the use of antagonistic organisms.

131-134

5.00 €

 

Evaluation of naturally occurring Pseudomonas spp. and a biopesticide
based on Trichoderma koningiopsis as potential biological control agents
of Olpidium virulentus in Fique

Alba Marina Cotes, Leonardo Sastoque, Lina Rada, Camilo Beltrán Acosta, Carolina González, Daniel Osorio, María C. Cepero de Garcia

Abstract: We report the presence of Olpidium virulentus in roots of fique plants where Macana
virus disease has been detected. When fique plants obtained in vitro or lettuce seedlings used as
model plant were inoculated with resting spores of O. virulentus, severe disease symptoms and
dramatic fresh weight reduction were expressed. With the aim to select potential biological
control agents, sixteen indigenous isolates corresponding to Pseudomonas spp. and a biopesticide
based on T. koningiopsis were evaluated on lettuce planted in soil infested with O. virulentus. Six
isolates of Pseudomonas spp. and the biopesticide based on T. koningiopsis reduced of both the
number of Olpidium sp. resting spores in roots, and the incidence and severity of the disease.
These microorganisms also improved germination, promoted plant growth, presented
solubilization phosphate activity and produced indol acetic acid (IAA).

135-139

5.00 €

 

Control of downy mildew on cucumber (Pseudoperonospora cubensis)
by plant extracts and a bacterial preparation

Christina Schuster, Andrea Nowak, Peggy Marx, Ute Gärber, Stavroula Konstantinidou-Doltsinis, Barrie Seddon, Annegret Schmitt

Abstract only

140

0.00 €

 

Biochar impact on plant development and disease resistance in pot trials
Yael Meller Harel, Max Kolton, Yigal Elad, Dalia Rav-David, Eddie Cytryn, Menahem Borenshtein, Ran Shulchani, Ellen R. Graber

Abstract: Biochar (charcoal) is the solid co-product of biomass pyrolysis (thermal
decomposition in the absence of oxygen). Amendment of soil with biochar is known to improve
soil tilth, nutrient retention and crop productivity. We studied the effect of soil-applied biochar on
plant productivity and plant foliar diseases. Biochar amendments to sand at levels of 1-3 weight
% enhanced the growth of tomato and pepper plants. In addition, suppression of the powdery
mildew caused by Podosphaera aphanis on strawberry plants grown in commercial coconut
fiber:tuff growing mix was observed. Resistance was maximal with 3% biochar amendment as
long as 6 months following planting. Reduction rates were 20 to 93% depending on the biochar
percentage and sampling date. However, gray mold caused by Botrytis cinerea on strawberry
leaves was not reduced upon biochar treatment. Similarly, root-nematode Meloidogyne javanica
was not affected by biochar amendments in tomato grown in sandy soil. Biochar amendments
moderately enhanced abundances of culturable general bacteria and Bacillus spp. but had no
apparent effect on other tested culturable microorganisms. Studies designed to clarify the
important systemic resistance metabolic pathways and its elicitors are underway. Biochar in soil
has a very slow turnover (half-life of 1000s of years), and therefore, when introduced to soil it
results in quasi-permanent sequestration of carbon. Soil treatment with biochar can thus serve as
a climate change mitigation tool and an agriculture adaptation tool.

141-147

5.00 €

 

Acidic pH supports efficient antagonist-based control
of the bacterial plant disease fire blight

Doris Pester, Ulrike Persen

Abstract only

149

0.00 €

 

Cooperating bacterial and fungal biocontrol strains with beneficial interactions
in sugar beet rhizosphere

Christin Zachow, Henry Müller, Ralf Tilcher, Jamshid Fatehi, Massimiliano Cardinale, Gabriele Berg

Abstract only

150

0.00 €

 

Influence of temperature on morphology and physiology of different isolates
of Ampelomyces quisqualis

Dario Angeli, Monika Maurhofer, Susanna Micheli, Cesare Gessler, Ilaria Pertot

Abstract: Temperatures significantly influenced the growth rate of the colonies and the highest
radial growth rate was measured at 20°C for all strains. Interestingly, original climate at which
A. quisqualis was isolated did not influence an adaptation to the temperature. In fact, strains
isolated in countries with a warm climate grew well at low temperature and vice versa. Observing
the conidial germination phase, tube length and especially germination rate of A. quisqualis
conidia increased greatly in the presence of powdery mildew conidia in different temperature.
Temperature in the tested range had no influence on the germination rate, but seems to have an
effect on tube length. These results suggest that different strains of A. quisqualis may react in a
different way to temperature and this aspect should be considered in the selection of commercial
strains, especially in a view of climate change.

153-157

5.00 €

 

Screening of new Trichoderma spp. isolates
Rudi Aerts, Bjorn Seels, Liesbeth Vogels, Tom Beyers, Kathleen Heyens

Abstract only

158

0.00 €

 

Selecting highly effective strains of Ampelomyces quisqualis for the control
of powdery mildews

Dario Angeli, Monika Maurhofer, Cesare Gessler, Ilaria Pertot

Abstract: Genetically different Ampelomyces quisqualis strains isolated from different locations,
fungal hosts and host plants were selected; pathogenicity and aggressiveness on different
powdery mildew species were evaluated. Under controlled conditions all the selected strains
reduced the sporulation of powdery mildews (Podosphaera xanthii, Podosphaera aphanis), but
with a different level of reduction among strains. Strains can be divided in highly and poorly
aggressive, and their behavior is similar on the studied powdery mildews. The susceptibility
versus A. quisqualis varies among the different tested powdery mildews. Results suggest that
there are not adaptations of A. quisqualis to powdery mildew species from whatever was the
original host specie the mycoparasite strain was isolated as no differential interaction was
observed, independently of their phylogenetic groups or geographical origin. Some of the tested
strains could be appropriate candidates for future commercial development in environmental
conditions to control different powdery mildew species.

159-163

5.00 €

 

Microbial diversity and populations-dynamics of the wheat phyllosphere
analysed by denaturing gradient gel electrophoresis (DGGE)

Birgit Antlinger, Sabine Fruehauf, Marc Lemmens, Rudolf Braun, Markus Neureiter

Abstract only

164

0.00 €

 

Endophytic and epiphytic bacteria associated with Sphagnum mosses
as perspective objects for agricultural biotechnology

Shcherbakov, A. V., Krikovtseva, A. V., Kuzmina, E. Yu., Berg, C., Malfanova, N. V., Cardinale, M., Berg, G., Chebotar, V. K., Tikhonovich, I. A.

Abstract: The aim of this study was to isolate promising bacterial strains associated with
Sphagnum mosses possessing beneficial properties for agricultural crops as perspective objects
for agricultural biotechnology. Previously it was shown that Sphagnum mosses are associated
with unique microorganisms which have important functions for Sphagnum mosses and for the
bog ecosystem as a whole. Study was focused on sampling of two Sphagnum species from bogs
located at different geographical areas of the Kolskyi peninsula (Russia) and Alps mountains
(Austria) which plays a different ecological role in the ecosystem of bogs. About 150 strains of
bacteria were isolated from the tissues of Sphagnum plants, their culture and morphology
properties have been investigated. Antagonistic properties of isolated strains against a number of
phytopathogenic fungi and bacteria have been studied. It was shown that more than 60% of all
isolates demonstrated strong antifungal properties (in vitro). Strains capable of promoting plantgrowth,
grow on the nitrogen-free medium and solubilize of not soluble phosphates were selected.
Selected strains can be used for further study in greenhouse experiments with agricultural crops.

165-171

5.00 €

 

Study of interaction between toxigenic fungi and endophytic bacteria
in the wheat grain for development of the methods for control
of toxigenic infections and production of high quality foodstuffs

Maria Fadeeva, Andrey Shcherbakov, Vladimir Chebotar

Abstract only

172

0.00 €

 

Priming – an eco-friendly strategy to improve abiotic stress tolerance
of Oilseed rape (Brassica napus)

Shashidar Yadav Asari, Sarosh Bejai, Johan Meijer

Abstract only

173

0.00 €

 

A new cellulase producing species Trichoderma parareesei nom. prov. reveals high
antagonistic potential against soil and plant pathogenic fungi

Lea Atanasova, Walter M. Jaklitsch, Monika Komon-Zelazowska, Christian P. Kubicek, Irina S. Druzhinina

Abstract only

174

0.00 €

 

The induction of resistance in inflorescences of Vitis vinifera L.
by Burkholderia phytofirmans strain PsJN against Botrytis cinerea Pers.

Essaid Ait Barka, Stéphane Compant, Fabienne Bailleul, Christophe Clément

Abstract only

175

0.00 €

 

Field studies of epidemiological development of Fusarium sp. in wheat
during growing period and in harvested crops with molecular methods

Astrid Bauer, Peter Büttner, Michael Schloter, Luitgardis Seigner

Abstract only

176

0.00 €

 

Biological control of root rot caused by Pythium aphanidermatum
and growth promotion in hydroponic cucumber with microorganisms from mangrove

Élida B. Corrêa, José Abrahão H. Galvão, Wagner Bettiol

Abstract: The prospection of biological control agents in similar environments to the microbe
application improves the chances of microorganisms establishment added to the environment.
The low survival of these beneficial microorganisms added to hydroponic environment is a
problem for the growth promotion and root rot biological control success in hydroponic crops.
Because of the environmental similarity between hydroponic systems and mangrove ecosystems,
the aim of this work was to evaluate the ability of mangrove microbes to control root rot caused
by Pythium aphanidermatum and to improve plant growth in hydroponic cucumbers. Among the
28 strains evaluated for disease control in small-hydroponic system using cucumber seedlings,
Gordonia rubripertincta SO-3B-2 alone or in combination with Pseudomonas stutzeri (MB-P3A-
49, MB-P3-C68 and SO-3L-3), and Bacillus cereus AVIC-3-6 increased the seedlings survival
and were subsequently evaluated in hydroponic cucumbers in a greenhouse. Bacillus cereus
AVIC-3-6 protected the plants from stunting caused by the pathogen and Gordonia
rubripertincta SO-3B-2 and Pseudomonas stutzeri MB-P3A-49 increased the plant growth. We
concluded that microorganisms from mangroves are useful as biocontrol agents and for
improving plant growth in hydroponic crops.

177-181

5.00 €

 

Strains of Coniothyrium minitans reduce the emission of apothecia
of Sclerotinia sclerotiorum

Marcelo A. B. Morandi, Carlos E. O. Silva, Lúcio B. Costa, Wagner Bettiol

Abstract: Sclerotia of Sclerotinia sclerotiorum (Ss) can survive for long time in soil and are the
main inoculum source of the white mold disease. An alternative for reducing this inoculum is the
use of parasites, such as Coniothyrium minitans (Cm). We evaluated the potential of Cm isolates
for the biological control of Ss in beans. The effect of the temperature on the growth of 15
isolated of Cm was evaluated in vitro. The hyperparasitism ability of Cm was evaluated in soil
infested with sclerotia and conditioned in pots. The infested soil was treated with conidia
suspension of the antagonists, fluazinan or sterile distilled water. After seven days at 20°C, the
sclerotia were removed from soil and placed inside Petri dishes over bean leaves previously
disinfested. The germination and parasitism of sclerotia were evaluated after 7 to 10 days. To
evaluate the apothecia emission, soil infested with sclerotia of Ss and treated as described was
maintained at 18°C and the number of emerged apothecia was counted up to 84 days after
inoculation. The emergence of bean plants in soil infested with sclerotia and mycelium of the
pathogen and treated as described was evaluated in greenhouse. The ideal temperature for growth
of Cm isolates varied from 18 to 19°C and at 30-35°C they were complete inhibited. The isolates
of Cm promoted less than 10% of reduction in viability of the sclerotia, but they significantly
reduced the emission of apothecia. Two isolates increased the emergence of plants in relation to
the inoculated check, but was significantly lower than the non-inoculated check. Field tests will
be conduct to confirm the potential of the selected isolates to reduce the inoculum source of the
pathogen.

183-187

5.00 €

 

Biocontrol activity of different Pseudomonas spp.
against Verticillium dahliae microsclerotia

Bisutti, Isabella Linda, Stephan, Dietrich

Abstract only

188

0.00 €

 

Effects of elevated atmospheric carbon dioxide on the biological control
of coffee leaf rust under controlled conditions

Lívia Mendes, Raquel Ghini, Wagner Bettiol

Abstract: The effect of elevated atmospheric CO2 concentration on biological control of coffee
leaf rust, caused by Hemileia vastatrix, was evaluated by leaf disc assay, under controlled
conditions. The biocontrol agents Bacillus subtilis, Bacillus pumilus and Lecanicillium
longisporum were applied 24h before, 24h after, and simultaneously with the H. vastatrix on leaf
discs (diameter of 1.5cm). The CO2 concentrations tested were: 380, 430, 700 and 1300ppm for
B. subtilis and B. pumilus; and 380, 430, 670 and 1200ppm for L. longisporum. The antagonists
were not affected by CO2 concentrations. B. subtilis was the most effective in controlling the
disease when applied before and simultaneously with pathogen.

189-192

5.00 €

 

Endophytic microorganisms isolated from coffee leaves, roots and branches
as plant growth promoters and biocontrol agents of coffee leaf rust

Harlen S. A. Silva, João P. L. Tozzi, César R. F. Terrasan, Wagner Bettiol

Abstract: Suppression of plant diseases and growth promotion due to the action of endophytic
microorganisms has been demonstrated in several pathosystems. Experiments under controlled
conditions involving 234 endophytic bacteria and fungi isolated from coffee leaves, roots and
branches were conducted with the objective of evaluating the germination inhibition of Hemileia
vastatrix urediniospores, the control of coffee leaf rust development in tests with leaf discs and
on plastic bags seedling, and to promote growth of coffee seedlings. None of the fungal isolates
induced plant growth or reduced disease severity. The bacterial isolates (identified by the fatty
acids profile analysis) 85G (Escherichia fergusonii), 161G, 163G, 160G, 150G (Acinetobacter
calcoaceticus) and 109G (Salmonella enterica) increased plant growth, the maximum being
induced by 85G. This isolate produced in vitro phosphatase and indol acetic acid. In assay to
control rust on coffee leaf disc, nine bacterial isolates, 64R, 137G, 3F (Brevibacillus
choshinensis), 14F (Salmonella enterica), 36F (Pectobacterium carotovorum), 109G (Bacillus
megaterium), 115G (Microbacterium testaceum), 116G and 119G (Cedecea davisae)
significantly reduced disease severity, when applied 72 or 24h before challenging with the
pathogen. In seedling tests most disease severity reduction was achieved by the isolates 109G and
119G. There was no correspondence between the organisms that promoted seedling growth and
those that reduced rust severity on seedlings or leaf discs.

193-196

5.00 €

 

Biological control of avocado root rots by suppressive organic amendments
Nuria Bonilla, Blanca Landa, José María Hermoso, Jorge González, Francisco Manuel Cazorla, Maira Martínez, Nùria Gaju, Antonio de Vicente

No abstract

197-198

5.00 €

 

Tomato proteome changes following soil application of Pseudomonas spp.
Pier Luigi Burzi, Anna Rita Veronesi, Roberta Roberti, Stefania Galletti, Claudio Cerato

Abstract: Two commercial biological products Proradix®Agro (Pseudomonas sp.) and Salavida
(P. trivialis) were assayed on young tomato plants under Phytophthora infestans challenge, under
greenhouse conditions. The products were water suspended following producer’s instruction and
applied to the soil 6 days before the foliar inoculation with P. infestans. Late blight symptoms
were observed 4 days after pathogen inoculation. Untreated plants appeared more infected than
treated plants, but no statistically significant difference was found between treatments and
controls or between the two products. However the application of each product led to a visible
plant growth enhancement. A comparative study was carried out in order to highlight proteome
differences among treated/untreated and inoculated/non inoculated plants. Total proteins were
extracted from leaves collected 48h after pathogen inoculation and analysed by two-dimensional
electrophoresis. The bioproduct application followed by the pathogen inoculation led to
up/down-regulation of some protein spots which were different from those affected by the
pathogen only. Mass-spectrometry analysis will be carried out in order to clarify if the observed
modifications concern the activation of defence mechanisms or the observed plant growth
promotion.

199-201

5.00 €

 

Characterization of site-directed mutants defective in HPR production
of P. fluorescens PCL1606 and its role in biocontrol

Claudia E. Calderon, Eva Arrebola, Cayo Ramos, Clara Pliego, Nuria Bonilla, Alejandro Pérez-García, Antonio de Vicente, Francisco M. Cazorla

Abstract: Pseudomonas fluorescens PCL1606 is a rhizobacteria with biocontrol activity against
many soil-borne phytopathogenic fungi. Its antagonist activity strongly correlates with the
production of the antibiotic 2-hexyl, 5-propyl resorcinol (HPR). However, other antibiotics could
be detected in P. fluorescens PCL1606, such as pyrrolnitrin (PRN) and hydrogen cyanide (HCN),
and could be also related to its antagonist activity. To determine the role of these antibiotics on
biocontrol, a collection of mutants in different antibiotics was initiated, studying in first place the
genes involved in the production of HPR. A collection of site-directed mutants to the
homologous dar operón, related to the HPR production in P. fluorescens PCL1606, have been
constructed. Characterization of the potential traits involved in the biocontrol activity of these
derivative strains were performed, including antagonism, motility, production of signal molecules,
biofilm formation and biocontrol. Our results showed a role of some of the dar genes in the
biocontrol.

203-206

5.00 €

 

STM of a biocontrol Pseudomonas pseudoalcaligenes strain to identify genes
involved in the interaction with Rosellinia necatrix

Clara Pliego, Jose I. Crespo, Cayo Ramos, Francisco M. Cazorla

Abstract: To identify bacterial genes that could contribute to biological control of the
phytopathogenic fungus Rosellinia necatrix, 1,104 mini-Tn5-tagged insertion mutants of the
biocontrol strain Pseudomonas pseudoalcaligenes AVO110 were screened in pools of ≤ 48 using
Signature Tagged Mutagenesis (STM). One hundred and twenty nine mutants were not recovered
from media containing R. necatrix exudates (BM-RE medium) 48 hours after inoculation,
suggesting that transposon insertion in these mutants affected genes required for growth and/or
survival in R. necatrix exudates. In a second round of STM screening, the number of mutants not
recovered from BM-RE was reduced to 25 mutants. To validate the screening results, these 25
mutants were tested in BM-RE medium for competition with the wild type strain AVO110; seven
of them, were less competitive or resistant to R. necatrix exudates than the wild type strain and
showed a single insertion of the transposon. DNA fragments flanking the Tn5 insertions in these
seven mutants were cloned, sequenced and analysed using BLAST software. These genes are
predicted to be involved in central metabolism, regulation and bacterial protection against
environmental signals.

207-216

5.00 €

 

Biocontrol activity of Agrobacterium bacteriophages
Natela Toklikishvili, Tamar Eliashvili, Tinatin Khukhunashvili, George Tsertsvadze, Marina Tediashvili, Erno Szegedi, Alexander Vainshtein, Leonid Chernin

Abstract only

217

0.00 €

 

Suppression of Agrobacterium caused crown gall disease of tomato
by rhizosphere bacteria and transgenic plants producing ACC deaminase

Natela Toklikishvili, Marina Tediashvili, Alexander Vainshtein, Susan Lurie, Erno Szegedi, Bernard R. Glick, Leonid Chernin

Abstract only

218

0.00 €

 

Influence of altitude on soil microbial community variability
Paola Elisa Corneo, Alberto Pellegrini, Monika Maurhofer, Claudia Maria Oliveira Longa, Cesare Gessler, Ilaria Pertot

Abstract: The concerns on climate change and in particular the increase of global temperature
are inflaming the public debate among scientist in recent years, especially regarding the possible
effect on environment, animals, plants and biodiversity. Microbial populations in soil are climatedependent.
Changes in soil microbial population could influence plant growth, leading to nonvisible
effects in short-term on agriculture system, but dramatically changing the soil ecosystem
in the long run. We aim at determining the effect of temperature and its relation with altitude on
the microbial community living in three different transects of altitude cultivated with grapevines
(cv. Chardonnay) in Trentino region. The final goal is to determine if temperature has a major
impact on microbial richness and variability. Soil samples were collected in each altitude transect
and cultivable microorganisms’ abundance and total community variability was analysed. A first
representative sampling has been carried out in November 2009, followed by a systematic
sampling along a W-shaped design in February 2010. In February bacterial and fungal growth
showed a significant difference due to the altitude (P < 0.05) inside each site, but not a general
trend was measured comparing the three different transects. Overall comparison of bacterial and
fungal growth from November to February showed a significant decrease which is attributable to
the different soil temperature in different periods.
Denaturant gradient gel electrophoresis of total fungi was set up with a firstly selected set of
primer to assess fungal variability. Isolation of morphologically different fungi allowed DGGE
marker creation.

219-222

5.00 €

 

Biological control of Rhizoctonia solani and growth promotion activity
of Trichoderma koningiopsis Th003 and Trichoderma asperellum Th034
formulations in potato (Solanum tuberosum)

Camilo Beltrán Acosta, Carlos Andrés Moreno, Paula Blanco, Laura Villamizar, Alba Marina Cotes

Abstract: Biological control agents Trichoderma koningiopsis Th003 and T. asperellum Th034
have shown high efficacy controlling potato damping-off disease. Both isolates were formulated
as water-dispersible powder (WP) and water-dispersible granule (WG) containing 1x1010 and
1x109 conidia.g-1, respectively. Aqueous suspension of these biopesticides [1x106 conidia ml-1]
was applied to potato seedlings in pot trials under greenhouse conditions in order to evaluate
biocontrol against Rhizoctonia solani and plant-growth-promoting effects. Application of Th003
WP and WG and Th034 WP resulted in 88 to 100% disease reduction. WG Th034 formulation
showed the lowest efficacy (54%) of disease control. The effect of Trichoderma spp. on biomass
accumulation, root and aerial part length, was not significant.

223-227

5.00 €

 

High population diversity of Cryphonectria parasitica in Croatia
might hinder natural biological control of chestnut blight

Jezic, M., Krstin, Lj., Novak-Agbaba, S., Celepirovic, N., Rigling, D., Curkovic-Perica, M.

Abstract only

228

0.00 €

 

Selection of Pichia onychis isolate for biological control of Botrytis cinerea
based on its eco-physiological characteristics

Carlos Andrés Moreno, Jennie Ramírez, Jimmy Zapata, Andrés Díaz, Alba Marina Cotes

Abstract: The effect of physiological parameters on growth, adherence to leaflets surface,
tolerance to UV radiation and biocontrol of indigenous antagonist yeasts Pichia onychis (Lv027,
Lv031. Lv297, Lv298, Lv299), Pichia anomala (Lv050) and Candida oleophila (Lv314) was
studied. All isolates showed higher growth in culture media with acid pH (3 to 6) than the growth
in basic pH conditions (≥ 8). All P. onychis isolates exhibited high tolerance stress conditions.
Isolates Lv297 and Lv314 presented high adherence to foliar surface and isolates Lv297 and
Lv050 gave effective control of B. cinerea. The fact that P. onychis Lv027 is effective biocontrol
agent and tolerate a wide range of growth and stress conditions makes it an excellent candidate
for production and field evaluation.

229-232

5.00 €

 

Climate effect on pathogen – biocontrol agents interaction
in the tomato – powdery mildew (Oidium neolycopersici) pathosystem

Ohad Agra, Dalia Rav David, Menahem Borenshtein, Ran Shulchany, Yigal Elad

Abstract: Disease development is the cumulative effect of various factors on the host and
pathogen whereby either a-biotic effects such as climate or beneficial microorganisms may affect
the severity of the disease. Oidium neolycopersici is the causal agent of tomato powdery mildew;
it causes powdery white lesions on the leaf surface, petioles and the calyx. Severe infections lead
to marked reduction in fruit size and quality and to leaf wilt. A slight change in temperatures may
allow either more severe disease (22 to 24°C change) or reduction in disease severity (26 to
28°C). Beneficial microorganisms can provide sufficient control, but they are sensitive to
environmental conditions. A better understanding of the influence of environmental factors on
pathogen – biocontrol agent interaction can help in improving their efficacy. The effect of
microclimate on the development and survival of two powdery mildew antagonists was
evaluated. When applied on detached leaves and incubated for 7-14 days at different
temperatures, RH, and disease levels, the bacterium (B2) survival was poorer at high
temperatures and low RH compared to the yeast (Y13). The microorganisms survived well at 10-
15°C and high RH. Tomato plants were grown in a net house with climate regimes of high and
low RH, and two disease levels were induced. Plants were sprayed weekly with the two
microorganisms. The bacterium survived better under high RH as compared with lower RH and
on leaves with powdery mildew as compared with symptomless leaves. The yeast was less
affected by microclimate conditions, and survived well for 14 days even with a single
application. We can conclude that the yeast survives better under different microclimate
conditions. In the present study, various abiotic factors were found to affect different aspects of
the tomato powdery mildew disease cycle. It was demonstrated that a slight change in
microclimate conditions can affect the outcome of the interaction of plants with a pathogen, and
of the plant-pathogen relationship with populations of control agents. The effects of climate
change may be different in different plant-pathogen systems. Nevertheless, it is clear that such
effects will occur and that adaptive measures need to be developed in order to respond to these
expected changes.

233-237

5.00 €

 

Hyphae-colonizing bacteria – a new course of biological control agents (BCA)
against rice sheath blight disease

Cuong Nguyen Duc, Mette Haubjerg Nicolaisen, Stefan Olsson, Jan Sørensen

Abstract only

238

0.00 €

 

Effect of climate parameters on induced resistance in strawberry powdery mildew
Hellen Angelica Quiñonez Gutierrez, Yael Meller-Harel, Dalia Rav David, Menahem Borenshtein, Ran Shulchany, Yigal Elad

Abstract: Induced disease resistance in plants is a physiological state of enhanced defensive
capacity elicited by specific stimuli, whereby the plant’s innate defences are potentiated against
subsequent challenges. This enhanced state of resistance is effective against a broad range of
pathogens and parasites, including fungi, bacteria, viruses, and nematodes. The two most clearly
defined forms of induced resistance are Systemic Acquired Resistance (SAR) and Induced
Systemic Resistance (ISR). The changing environmental conditions may lead to changes in the
activity and survival of organisms. Powdery mildew (Podosphaera aphanis) is one of the major
fungal diseases of strawberry world-wide and is expected to increase its distribution under
changing climatic conditions. In the present research we study induced resistance in strawberry
plants under the changing environmental conditions that are expected due to global warming.
Inducers that are tested in the present study include Trichoderma harzianum T39, acibenzolar-Smethyl
(Bion), a new SCNB2 inducer and isolates of a bacterium and a yeast. These agents not
only effectively suppressed powdery mildew on leaves when sprayed on the canopy, but also
induced systemic resistance when applied to the root zone while disease was evaluated on the
leaves. Similarly lower leaf application resulted in upper leaf disease suppression. Plant growth
was enhanced in the presence of the biological inducers in the root zone, especially under limited
irrigation conditions. The effect of different temperatures and water stress conditions on induced
resistance is further studied. Furthermore, the effect of the climate parameters on the expression
of induced resistance genes will be studied.

239-243

5.00 €

 

Screening of Pseudomonas fluorescens strains isolated from Iranian soils
for their potential to produce antifungal metabolites
and to control Rhizoctonia root rot of bean

Fatemeh Jamali, Abbas Sharifi-Tehrani, Monika Maurhofer

Abstract only

244

0.00 €

 

Biocontrol of powdery mildew fungi by plant growth promoting rhizobacteria
Laura García-Gutiérrez, Houda Zeriouh, Antonio de Vicente, Alejandro Pérez-García

No abstract

245-246

5.00 €

 

Control of pepper bacterial spot with bacteriophages
Katarina Gašić, Milan Ivanović, Anđelka Ćalić, Aleksa Obradović

Abstract only

247

0.00 €

 

In vitro antifungal activity of Brassicaceae spp. tissue compounds
on strawberry root pathogens

Nataša Duduk, Mirko Ivanović, Katarina Gašić, Aleksa Obradović

Abstract only

248

0.00 €

 

Isolation and characterization of bacteriophages specific to Xanthomonas euvesicatoria
Katarina Gašić, Milan Ivanović, Anđelka Ćalić, Aleksa Obradović

Abstract only

249

0.00 €

 

Nicotinic acid and nicotinamide on pear and apple, analyzed in terms
of cultivar and blossom age, are not limiting factors for Erwinia amylovora growth

Thomas Paternoster, Urska Vrhovsek, Fulvio Mattivi, Cesare Gessler, Ilaria Pertot

Abstract only

250

0.00 €

 

Natural antagonists of the grapevine root rot fungus Roesleria subterranea
Sigrid Neuhauser, Ramona Held, Lars Huber, Martin Kirchmair

Abstract: Roesleria subterranea is a root-pathogenic ascomycete of grapevine causing severe
economic loss in vineyards in Germany, Luxemburg and the US. Currently, no efficient control
methods are available. To isolate potential fungal, antagonist soil-particles were placed onto wellestablished
R. subterranea cultures. Fungi growing out of the soil particles were isolated. The
majority of the isolated fungal strains belonged to the genus Clonostachys. These isolates
together with Trichoderma spp. and Clonostachys spp. strains previously isolated from vineyard
soils, endophytic isolates from diseased vines, and commercialised strains were tested in dual
culture for their antagonistic effect against four Roesleria strains. All Roesleria strains reacted
with an enhanced production of a green pigment in the contact zone that limited or stopped the
growth of the antagonistic fungi. Most Trichoderma strains were able to restrict the growth of
Roesleria and to overgrow the colony. Two out of nine Clonostachys strains restricted the growth
of all four Roesleria strains. In contrast to Trichoderma a bleaching of the green pigment was
observable when Clonostachys strains were growing over the Roesleria colonies. Whether or not
rapid overgrowth of Roesleria colonies or bleaching of the green pigment is the key character of
an effective antagonist cannot be decided at the moment. Promising strains of Trichoderma and
Clonostachys will be tested in future pot experiments and field trials.

251-254

5.00 €

 

Alteration of the morphology of tomato roots due to Fusarium oxysporum
f. sp. lycopersici, arbuscular mycorrhizal fungi and phosphorus supply

Alexandra Horner, Karin Hage-Ahmed, Ingrid Langer, Siegrid Steinkellner

Abstract: The wilt-inducing pathogen Fusarium oxysporum f.sp. lycopersici, a soil borne fungus
occasionally causing considerable yield losses in tomato production, invades the vascular system
and induces characteristic alterations in tomato roots and stems. Arbuscular mycorrhizal fungi
(AMF) have been documented for their biocontrol properties; in particular they are well known to
improve the plants nutritional status, mainly phosphorus. We studied the effects of Fusarium
oxysporum f.sp. lycopersici and of the AMF Glomus mossae on tomato root morphology.
Additionally the plants were treated with a nutrient solution containing different concentrations
of phosphorus. Root length, root surface area (important indicators for water and nutrient uptake)
and average root diameter were estimated using the image analysis program WinRHIZO. Our
data indicate an alteration of these parameters depending on the treatment.

255-258

5.00 €

 

A cold-active antifungal Pseudomonas fluorescens isolate from Greenland
Charlotte Frydenlund Michelsen, Lisa Munk, Eigil de Neergaard, Dan Funck Jensen, Kenneth Høegh, and Peter Stougaard

Abstract: Potato soils from South Greenland contain a number of fungal-inhibiting bacteria. One
isolate, Pseudomonas fluorescens strain In5, shows high inhibition of several plant-pathogenic
fungi e.g. Rhizoctonia solani, Pythium aphanidermatum, Fusarium graminearum and
Phytophthora infestans in in vitro inhibition assays. Also in a microcosm assay strain In5 showed
the ability to suppress R. solani. By the use of different biochemical and genetical methods, strain
In5 was found to contain the capacity to produce the antifungal compounds hydrogen cyanide
(HCN) and non-ribosomal peptide (NRP). Random mutagenesis with a Tn5 derived transposon
resulted in one mutant deficient in HCN production and two mutants with reduced antifungal
activities.

259-263

5.00 €

 

The importance of applied biocontrol agents (BCAs) and their metabolites
compared to that of the natural microbiota on strawberry

Birgit Jensen, Inge M. B. Knudsen, Dan Funck Jensen, Birgitte Andersen, Kristian Fog Nielsen, Ulf Thrane, John Larsen

Abstract only

264

0.00 €

 

Screening for hydrolytic enzymes produced from indigenous bacterial isolates
Sanaa S. Kabeil, Sawsan A. Abdelatif, Sahar A. Zaki

Abstract: By screening different soil samples collected from Monofia governorate in Egypt,
twelve bacterial isolates were isolated and tested against different root rot fungi namely,
Aspergillus niger var. niger Tiegh., Botrytis fabae Sardiña, Fusarium oxysporum var. orthoceras,
Botrytis cinerea Pers., Fusarium avenaceum, Fusarium oxysporum Schltdl., Helminthosporium
spp., Alternaria alternata (Fr.) Keissl., Fusarium solani (Mart.) Sacc., Bipolaris oryzae (S. Ito &
Kurib.), Rhizoctonia solani J. G. Kühn, Pythium ultimum (Trow). Different inhibition zones and
different hydrolytic enzyme production obtained from these bacterial isolates. Four of them
designated as D, F, E and G showed a high inhibition zone and a high production of different
hydrolytic enzymes identified as genera Pseudomonas (D), Bacillus (two different isolates, E and
G), and Acinetobacter (F); according to biochemical testes using API Kits, and confirmed with
molecular identification using 16S rDNA. Isolate D (Pseudomonas sp.) have 96% inhibition
against Fusarium solani. All isolates have more or less 90% inhibition against wilt diseases
caused by different species of Fusarium. Strain E and G (Bacillus sp.) showed 88, 89% inhibition
against these harmful fungi. Also strain F (Acinetobacter) showed 96% inhibition against
Pythium ultimum causing damping off to very economic plants. High production of several
hydrolytic enzymes like glucanase, protease, chitinase and lipase were detected by these bacterial
isolates.

265-273

5.00 €

 

Bio-products for ecologically sound and sustainable horticultural production –
Investigations into Enterobacter radicincitans on radish

Beatrice Berger, Helmut Junge, Silke Ruppel

Abstract only

274

0.00 €

 

Exploiting natural biodiversity within wild olives havens for selecting rhizobacteria
with antagonistic potential against Verticillium dahliae Kleb.

Sergio Aranda, Miguel Montes-Borrego, Rafael M. Jiménez-Díaz, Blanca B. Landa

Abstract Wild olive trees (Olea europaea subsp. sylvestris) are considered an important and
unexplored source of genetic variability for traits of agronomic and biotechnological interest such
as reservoirs of specific and well adapted rhizobacteria antagonistic to Verticillium dahliae, the
causal agent of Verticillium wilt, the most important disease of cultivated olive worldwide. A
polyphasic approach was used by determining the structure and diversity of bacterial
communities in the rhizosphere soil and roots of 17 samples of wild olives havens in Cádiz, and
Córdoba provinces in the Andalusia region at southern Spain. Results of FT-RFLP patterns of
16S rDNA sequences revealed a high heterogeneity of bacterial community composition
suggesting the existence of plant genotype-site specific factors. By culture-dependent approach,
675 culturable bacterial isolates were selected and 94 of them (14%) showed different levels of
antagonistic activity against the defoliating pathotype of V. dahliae as well as production of
different enzymes and secondary metabolites. 16S rDNA gene sequences identified most of those
strains as Pseudomonas and Bacillus spp.

275-278

5.00 €

 

Biochemical characterization of antifungal metabolites produced
from Greek indigenous Streptomycetes, examined as biocontrol agents

Grammatiki Kanini, Efstathios Katsifas, Dimitris G. Hatzinikolaou, Amalia D. Karagouni

Abstract only

279

0.00 €

 

Identification and characterization of purple-pigmented bacteria
from rhizosphere of wild and cultivated olives in Andalucia, Spain

Sergio Aranda, Blanca B. Landa

Abstract only

280

0.00 €

 

Potential climatic suitability for Fusarium wilt of chickpeas and its biocontrol agents
under current and future climatic change scenarios

Juan A. Navas-Cortés, Blanca B. Landa

Abstract only

281

0.00 €

 

Biological control of soybean white mold by Trichoderma spp. isolates
Cleusa M. M. Lucon, Érica A. S. Pedro, Luiz A. Fukuhara

Abstract only

282

0.00 €

 

Detection of the fire blight pathogen Erwinia amylovora from bees
with molecular tools as part of an alternative forecasting method

Thomas Leichtfried

Abstract: Fire blight is considered the bacterial disease with the greatest economic impact in
pome fruit production. The causal agent Erwinia amylovora can be dispersed by wind, rain,
inadequate cultural measures and arthropod vectors e.g. honeybees (Apis mellifera). Honeybees
as main pollinators in fruit crops spread the pathogen while collecting nectar and pollen from
infected blossoms and could thus serve as early indicators for the presence of the bacterium in
orchards. With regard to the expected global climate change, the infection conditions for E.
amylovora could be favoured. Existing abiotic based fire blight forecasting systems would need
adaptation, and monitoring of the pathogen’s presence on major vectors with molecular tools
could significantly improve precast of E. amylovora infections. As part of a master thesis,
molecular tools for the detection of E. amylovora in honeybees were developed and tested. For a
reliable detection of the pathogen in honeybees with PCR a specific purification of the bacterial
DNA is necessary. An existing method for DNA extraction of microorganisms was adapted for
honeybees. The sensitivity of the method could be proved by qualitative PCR in dilution series of
the pathogen artificially injected in the vector. In addition, bees caught on pome fruit production
sites during the growing season were investigated with the established method. To quantify E.
amylovora in honeybees and to determine the amount of bacteria on a single honeybee a real time
PCR method was used. This information about bacterial quantity is considered crucial to monitor
the infection pressure on the flowering pome trees. In order to clarify the exact position of the
pathogen on the vector individual parts of the bees were investigated for presence and quantity of
E. amylovora. It could be demonstrated that the developed methods allow both, a rapid and a
sensitive detection of E. amylovora directly from bees and that variable quantities of bacteria on
different parts of the vector occur. It is proposed that this newly developed system could be
applied to increase accuracy in infection prognosis of E. amylovora in orchards.

283-284

5.00 €

 

Lactic acid bacteria as biocontrol agents of soil-borne pathogens
Matthias Peter Lutz, Vincent Michel, Chloé Martinez, Cédric Camps

Abstract: Lactic acid bacteria (LAB) might be a novel promising bacterial group in the
biological control of soil-borne pathogens. The potential of this bacterial group to suppress
certain fungi has been shown in the control of post-harvest diseases of fruits and vegetables, but
not much is known about their ability to protect plant roots against soil-borne pathogens. From
soil and the rhizosphere of maize, rye, carrots, garden soils and compost from two origins 294
isolates of LAB have been obtained and tested in a confrontation assay against Pythium ultimum.
In total, about 75% of the isolates showed an inhibitory effect. The most promising isolates were
further tested in the pathosystem Pythium/tomato in pot trials. The LAB were able to protect the
plants against the pathogen. Additionally the germination of tomato was significantly enhanced
when the seeds were treated with LAB. Therefore we conclude that LAB are a promising
bacterial group for use in the biological control of soil-borne pathogens.

285-288

5.00 €

 

Biological control of oyster mushroom green mould disease
by antagonistic Bacillus species

Adrienn Nagy, László Manczinger, Dóra Tombácz, Lóránt Hatvani, Júlia Győrfi, Zsuzsanna Antal, Enikő Sajben, Csaba Vágvölgyi, László Kredics

Abstract: The occurrence of Trichoderma pleurotum and T. pleuroticola in cultivation of oyster
mushroom (Pleurotus ostreatus) frequently results in serious crop losses. Bacillus strains were
isolated that are very effective in antagonizing the oyster mushroom pathogenic T. pleurotum
without having a negative effect on P. ostreatus. A Bacillus subtilis and a B. amyloliquefaciens
strain, as well as a streptomycin-resistant derivative of a B. licheniformis strain proved to be very
effective against the tested T. pleurotum strain in vivo. The B. amyloliquefaciens strain is a potential
biocontrol candidate, as in addition to the lack of antagonistic activity towards P. ostreatus, it
increased the crop yield.

289-293

5.00 €

 

Impact of genetically modified wheat on the frequency and genetic diversity
of root colonizing Pseudomonads associated with soil fertility

Joana Meyer, Christoph Keel, Monika Maurhofer

Abstract only

294

0.00 €

 

Effectiveness of Trichoderma spp. in the yield of table grapes
affected by Cylindrocarpon macrodydimum in a semi arid region of Chile

Montealegre, J. R., Sánchez, S., Pérez, L. M., Rivera, L.

Abstract: The effectiveness of two Trichoderma spp. formulations in the control of
Cylindrocarpon macrodidymum affecting table grapes cropped under a semi arid climate
conditions (3th Region of Chile in Copiapó), was evaluated through trials conducted during two
seasons. The orchards were selected according C. macrodydimum damage (low growing ratio and
yield of the plants). Treatments were run applying Trichoderma spp. into the soil as: a solid
formulation, sodium alginate pellets including either a wild or an improved strain, and a liquid
formulation of a commercial Trichoderma spp. biofungicide. An absolute control was also set.
The experimental design was a complete randomized block. Results were analyzed by ANOVA
and Tukey`s test. C. macrodidymum populations, before and after treatments were compared to
controls, as well as percent of yield increase and yield per plant. Survival of Trichoderma spp. in
the soil of both formulations was also evaluated. Results showed that no statistical differences
were observed in the C. macrodidymum populations after Trichoderma spp. treatments
independently of the type of formulation. However, percent of yield increase was statistically
significantly higher than control, when Trichoderma spp. formulations were applied. The
Trichoderma populations in the soil after treatment with the solid formulations was higher than
the one obtained with the liquid biofungicide. The results indicate that soil treatments with
Trichoderma spp. in table grapes affected by C. macrodidymum resulted in a yield increase in
treated plants cropped in a semi arid region of Chile.

295-298

5.00 €

 

Consumers’ attitude to fruit produced by using biocontrol agents
and climate change mitigation practices

Riccarda Moser, Ilaria Pertot, Roberta Raffaelli

Abstract: Concerns for potential risks related to the use of chemical pesticides have encouraged
research of low impact alternatives as biocontrol agents (BCAs) and the implementation of a
more environmentally sound agricultural management as the integrated pest management (IPM)
and organic agriculture. A new regulation was recently implemented in the European Union (EC
No 834/2007), which establishes the legal framework for all levels of production, distribution,
control and labelling of organic products. Most of the European consumers are now familiar with
IPM and organic products. Climate change is becoming a hot issue and mitigation practices are
under discussion in agriculture, too. The level of consumers’ awareness of mitigation practices
and their willingness to pay for products produced with low carbon emission is unknown.
Consumers’ attitudes and preferences to fruit (apples) produced by using BCAs instead of
chemical pesticides and/or climate change mitigation practices were evaluated in a choice
experiment. Preference for other apple determinants such as origin, appearance and price were
also considered. The survey was administered to 96 consumers in different supermarkets in
Northern Italy during fall 2009. Results show that in purchase decision, origin and price are the
major determinants, followed by organic production and good appearance. Using BCAs and
climate change mitigation practices increased the probability of purchasing apples. However,
only coefficient associated to climate change is statistically significant and respondents are
willing to pay a premium price of about 0.50 Euro/kg. Moreover, results indicate that when
buying apples most people have specific requirements in mind regarding method of production,
origin, appearance and price, but comparing choices made by the respondents with their
individually-stated minimum requirements, the majority violated them.

299-303

5.00 €

 

Functional characterization of four Serratia isolates in relation
to their biocontrol efficacy against Rhizoctonia solani

Neupane, S., Högberg, N., Alström, S., Andersson, B., Finlay, R.

Abstract only

304

0.00 €

 

Proteomic approach to characterize the biocontrol mechanism
of Trichoderma harzianum T39 in grapevine

M. Cristina Palmieri, Michele Perazzolli, Vittoria Metafora, Angela Bachi, Ilaria Pertot

Abstract: Some biocontrol agents can activate defense mechanisms and increase grapevine
resistance against pathogens. In particular Trichoderma harzianum T39 induces systemic
resistance and significantly reduces downy mildew symptoms caused by Plasmopara viticola.
This biocontrol agent could offer a powerful alternative to chemical pesticides, but more
knowledge of the mechanisms of resistance induction is required in order to maximize its
efficacy. A proteomic approach was undertaken to increase our understanding of the basis of
resistance to these major pathogen and to identify potential new priming effectors in grapevine.

305-309

5.00 €

 

Mulching highbush blueberry with Trichoderma atroviride SC1-inoculated barks
controls Armillaria root rot

Alberto Pellegrini, Daniele Prodorutti, Veronica Leoni, Ilaria Pertot

Abstract only

310

0.00 €

 

Effect of temperature on the antagonism between biocontrol agents
and Cylindrocarpon destructans

Alberto Pellegrini, Daniele Prodorutti, Ilaria Pertot

Abstract: Two in vitro experiments were carried out; the first experiment compared the growth
at different temperature of a strain of Cylindrocarpon destructans isolated in Trentino region
(Northern Italy) and the second experiment tested the antagonistic activity of several biocontrol
agents against C. destructans. C. destructans was plated on potato dextrose agar in the Petri
dishes and incubated at different temperatures (-1, 4, 20, 23, 25 and 27°C). The growth of
C. destructans was evaluated. In the dual-culture test we verified the activity of five different
biocontrol agents against C. destructans at 4, 23 and 27°C. The efficacy of the biocontrol agents
in inhibiting pathogen growth was measured 2, 4, 9, 14, 19, 24, 29 days after inoculation. The
pathogen grew at all tested temperatures even if at different speed. Trichoderma atroviride SC1
was the most effective antagonist of C. destructans in the dual-culture test at all tested
temperatures.

311-313

5.00 €

 

Survival of Trichoderma atroviride SC1 on grapevine pruning wounds
and efficacy against Esca disease agents

Alberto Pellegrini, Veronica Leoni, Ilaria Pertot

Abstract: Esca disease is causing damage in vineyards in several parts of the world. The disease
is caused by three different fungi (Phaeomoniella chlamydospora, Phaeoacremonium aleophilum
and Fomitiporia mediterranea), On the whole these pathogen affects the shoot of the trunk and
the branches with chronic or acute evolution. At the moment the prevention of pruning wounds
infection by following correct cultural practices remains the main way to manage the disease but
the possibility of introducing microorganisms as biological control seems to represent an
alternative or a complementary strategy. We studied the survival of Trichoderma atroviride SC1
on pruning wound vineyard (107 conidia/ml) applied during winter at two different stages (BBCH
00 and 01), and its efficacy to reduce the colonization of Pal and Pch of grapevine pruning
wounds in potted plants. T. atroviride SC1 can survive in the wood for several months, but the
percentage of colonised wounds decreases during time, probably because of the temperature rise
in the vineyard. For this reason, 45 different ingredients (wetting agents, UV protectors,
nutritional factors, etc.) were tested in the formulation of a semi-commercial product based on
T. atroviride SC1 with the aim to improve its germination and persistence on pruning wounds.
T. atroviride SC1 can successfully control wound infections of Pch and, at lower extent, of Pal.

315-318

5.00 €

 

Dissecting positive or negative effects of abiotic stress on grapevine self-protection
induced by Trichoderma harzianum T39

Michele Perazzolli, Benedetta Roatti, Bahcine Ezzahi, Oscar Giovannini, Ilaria Pertot

Abstract: Downy mildew is one of the most destructive grapevine diseases, and its control is
based on the application of fungicides. There is increasing interest to reduce reliance on
pesticides for disease control in viticulture and to focus on alternative methods, such as
biocontrol agents. Several Trichoderma spp. strains are active against numerous plant pathogens,
and their biocontrol activity is based on different mechanisms. In grapevine, T. harzianum T39
activates a plant-mediated resistance and reduces downy mildew symptoms, but its efficacy
under abiotic stress conditions have not jet investigated. Our aim is to investigate the relationship
between drought stress and P. viticola infection, and to characterize the efficacy of T. harzianum
T39-induced resistance under water stress conditions.

319-323

5.00 €

 

Temperature affects antagonism of Trichoderma spp. against Armillaria mellea in soil
Claudia Maria Oliveira Longa, Ilaria Pertot

Abstract: Armillaria mellea root rots cause extensive economic losses on crops and in forest.
Currently available chemical fungicides are ineffective in controlling the disease. Biological
control, either alone or integrated with agronomic approaches may have better perspectives.
Abiotic factors may affect biological control by influencing the activity of the biocontrol agents
and the susceptibility of soil-borne pathogens to microbial antagonism. The effect of temperature
on antagonism of Trichoderma spp. against A. mellea was evaluated in soil microcosms. Five
plugs of A. mellea mycelium and rhizomorphs, protected by sterile lens tissue, were put between
two layers of 200g of sieved sterile soil inoculated with 106 conidia of the testing microorganisms
(T. atroviride SC1, T. virens TG1 or T. rossicum TG5) in polypropylene bottles (microcosms
sets). Microcosm sets were maintained for seven days at 10 and 20°C. Antagonistic effect was
evaluated as percentage of pathogen’s growth failure on malt extract agar (reduction of vitality).
Trichoderma spp. isolates varied in their antagonistic abilities to parasitize A. mellea and the
antagonism was highly affected by temperature. Antagonistic ability of T. atroviride SC1 was
low at 10°C, while the other two isolates were inactive against A. mellea at this temperature.
Conversely at 20°C pathogen vitality was significantly reduced by the presence of each tested
microorganism (Tukey’s test, P ≤ 0.05). Consortia of isolates did not increase global antagonistic
ability at 10°C. Soil temperatures can differentially influence the antagonistic ability of
microorganisms and this aspect is crucial in a view of climate change and increasing
temperatures.

325-328

5.00 €

 

Effect of temperature on induced systemic resistance on grape
against Plasmopara viticola and on pathogen’s population

Benedetta Roatti, Michele Perazzolli, Bahcine Ezzahi, Giovanni Broggini, Cesare Gessler, Ilaria Pertot

Abstract: Some biocontrol agents are known to induce systemic resistance (ISR) in plants
reducing the severity of downy mildew disease caused by Plasmopara viticola, but little is
known about the effect of temperature on this mechanism. Population genetic studies revealed a
considerable diversity of P. viticola in vineyards. The aim of this study is to understand the effect
of temperature on Trichoderma harzianum T39-induced systemic resistance on grape and to
study the effect of temperature on populations of P. viticola. Grapevine plants treated with T39 at
different temperatures are inoculated with P. viticola and biological effects are evaluated. Leaves
are also collected for ISR/SAR genes expression analysis. P. viticola isolates are genotyped and
phenotyped (i.e. incubation time, sporulation amount). Genotypes are co-inoculated at different
temperatures and the population is analyzed with microsatellite markers and real time PCR. The
results will allow a better understanding of the role of the plant and the pathogen in a view of
climate change.

329-333

5.00 €

 

The plant genotype affects the outcome of the beneficial interaction
between tomato and selected Trichoderma spp. strains

Michelina Ruocco, Marina Tucci, Luigi De Masi, Monica de Palma, Matteo Lorito

Abstract only

334

0.00 €

 

Isolation of fluorescent Pseudomonas strains antagonistic to the mushroom pathogen,
Pseudomonas tolaasii

Enikő Sajben, László Manczinger, Adrienn Nagy, Csaba Vágvölgyi

Abstract only

335

0.00 €

 

Bacterial rhamnolipids as general elicitors conferring resistance
to Botrytis cinerea in grapevine

Sanchez, L., Varnier, A. L., Vatsa, P., Rabenoelina, F., Kauffmann, S., Pugin, A., Clément, C., Baillieul, F., Dorey, S.

Abstract only

336

0.00 €

 

Streptomyces GB4-2 triggers rapid and widespread callose deposition
in Arabidopsis thaliana leaves in response to fungal infection

Fengler, S., Karidaki, V., Mailaender, S., Tarkka, M. T., von Rad, U., Hampp, R., Schrey, D.

Abstract only

337

0.00 €

 

Light determines the confinement of a pathogen by an antagonistic endophyte
Schwarz, D., Fakhro, A., von Bargen, S., Büttner, C., Franken, P.

Abstract only

338

0.00 €

 

Sources of aflatoxin-degrading enzymes for potential use in decontamination
of agricultural products

Natalia Zhemchuzhina, Yulia Semina, Larisa Shcherbakova, Vitaly Dzhavakhiya, Bruce Campbell

Abstract: To find microbial sources of enzymes which catabolaze aflatoxin we screened 41
fungal strains, belonging to 18 genera, which co-colonize natural substrates with toxigenic A.
flavus. Aflatoxin-catabolizing potential of each strain was assessed, in vitro, by cultivation for 7
days in liquid media supplemented with aflatoxin B1. After incubation, the amount of B1
remaining in the cultural filtrates was quantified by HPLC and compared to that of controls (no
fungal inoculum). Among the tested strains, 28 were able to degrade B1 to varying degrees. The
most active B1 degradation was found in isolates of Phoma glomerata, Cladosporium sp.,
Gliocladium roseum and Ulocladium sp., which catabolized 80-98% of the B1. One time-course
study on aflatoxin catabolism showed that G. roseum degraded almost 50% of the B1 within the
first 3 days of culture. Interestingly, one biocontrol agent, Trichoderma viride, degraded B1 in
submerged, liquid cultures only if the fungus was cultured on solid agar containing B1 prior to
inoculation into liquid media.

339-343

5.00 €

 

Atoxigenic black aspergilli populations in Trentino: a natural biocontrol
threaten by climate change?

Michelangelo Storari, Giovanni A. L. Broggini, Ilaria Pertot, Cesare V. Gessler

Abstract only

344

0.00 €

 

Screening for peptaibiotics in commercially available Trichoderma
biocontrol products by LC-MS/MS

Norbert Stoppacher, Susanne Zeilinger, Rudolf Krska, Rainer Schuhmacher

Abstract: A growing number of strains of the filamentous soil fungus Trichoderma are
commercially available as plant strengtheners, plant growth promoters or as biocontrol agents
(BCA) of phytopathogens. When interacting with the pathogenic fungus and the plant,
Trichoderma spp. produce secondary metabolites, such as peptaibiotics, which are believed to
play a key role in the crosstalk between the respective organisms. Peptaibiotics are linear nonribosomal
peptides with antibiotic properties, which contain the non-proteinogenic amino acid a-
aminoisobutyric acid (Aib). In this study, we screened Trichoderma strains present in commercial
BCA products from five suppliers for their ability to produce peptaibiotics, when grown in liquid
culture medium. Using an analytical workflow consisting of liquid chromatography–mass
spectrometry (LC-MS) and subsequent LC–tandem MS (LC-MS/MS) experiments, we were able
to detect 12 peptaibols of the group of trichotoxins, two members of the trichorzin HA group and
11 novel peptaibols in cultures of three of the investigated BCA strains.

345-350

5.00 €

 

Control of Verticillium wilt in pepper with two bacterial-based products
and one fungal agent: a laboratory comparison

Rafael Carballeira, Javier Veloso, José Díaz

Abstract: Two commercial products, AstonaTM and BotrybelTM, consisting of spores of the
bacteria Bacillus pumilus and Bacillus velezensis, respectively, were compared with a nonpathogenic
isolate of Fusarium (Fo47) in the biocontrol of Verticillium dahliae in pepper
(Capsicum annuum). The assays were conducted in a growth room with controlled temperature
(25°C) and light (16h light – 8h dark). The biocontrol agents were applied once by dipping the
roots of pepper plants in a suspension of the bacteria/fungus. 48h after this treatment, plants were
inoculated with a suspension of 106 conidia/ml. Symptoms as stunting, determined by stem
length, were recorded weekly for 4 weeks. A significant reduction of the symptoms was observed
for all the groups treated with any of the three biocontrol agents, but Fo47 was by far the most
effective. The colonization of the plant by V. dahliae was monitored by sowing consecutive
fragments of the stem in PDA supplemented with antibiotics. Samples of root and stem were
collected 48h after treatment with the biocontrol agents to be further analysed. Gene expression
of two defence-related genes and b-1,3-glucanase and chitinase enzyme activities were assayed
searching for an evidence of the induction of plant defence by the protectant bacteria/fungus.

351-354

5.00 €

 

MBI-R20, a new pesticide, induces resistance in plants and controls
both fungal and bacterial plant diseases

Hai Su, Marja Koivunen, Tim Johnson, Julie Versman, Pam Marrone

Abstract: A biofungicide formulated from Reynoutria sachalinensis extract, MBI-R20, controls
powdery mildew and other diseases on many crops by induction of the production of plant
phytoalexins and simple phenolics, and by inhibition of conidia germination. Field studies
conducted in multiple locations on specialty crops such as cucurbits, tomato, lettuce, and wine
grapes indicate good efficacy against major fungal and bacterial plant pathogens. In a field study
on tomato, MBI-R20 applied either alone or in a tank mix with common chemical fungicides
resulted in a significant reduction in severity of bacterial spot (Xanthomonas campestris pv.
vesicatoria) and reduced incidence of powdery mildew (Oidium neolycopersici). The efficacy
was equal to that obtained with the growers’ standard chemical pesticide treatments included in
the study. For powdery mildew control, MBI-R20 as a stand-alone treatment (8 applications
every 5-7 days) performed better at 1.0 than 0.5% concentration in this study, but both rates
controlled bacterial leaf spot equally well. There were no significant differences among the MBIR20
stand-alone, tank-mix and rotation treatments in the control of both test pathogens, which
indicates that MBI-R20 can be successfully included in integrated pest management programs to
decrease the risk of resistance development among plant pathogens. Preliminary results from
recent field studies on wheat suggest that besides pesticidal effect against Septoria sp., MBI-R20
also has a beneficial effect on yield quality in terms of higher protein content and grain weight.

355-358

5.00 €

 

P 75 Molecular and functional characterization of Trichoderma harzianum T39
determinants of resistance induction in grapevine

Lucie Vincenot, Michele Perazzolli, Ilaria Pertot

Abstract: Plasmopara viticola, the causal agent of downy mildew, is one of the most damaging
diseases of grapevine (Vitis vitifera) worldwide. In grapevine, Trichoderma harzianum T39
activates a plant-mediated systemic resistance and significantly reduces downy mildew
symptoms. Preliminary results suggest an implication of T39 biological status (i.e. grown
conditions and ages of conidia) in the biocontrol efficacy. To further understand the mechanisms
of T39-induced resistance, we aimed to characterize the fungal features for an efficient selfprotection
activation in grapevine. By the parallel characterization of fungal and plant genes, the
impact and properties of the resistance inducer will be determined. This study will help to
understand the role of physiological factors in the efficacy of biocontrol agents, in order to
maximize their effect especially during changes of abiotic conditions.

359-363

5.00 €

 

Characterization of Trichoderma isolates of marine origin and assessment
of their potential as biocontrol agents

Inbal Gal-Hemed, Lea Atanasova, Monika Komon-Zelazowska, Irina S. Druzhinina, Christian P. Kubicek, Ada Viterbo, Oded Yarden

Abstract only

364

0.00 €

 

Development of methods to assess the efficacy of non-chemical seed treatments
for control of loose smut in barley and wheat

Jan Wunderle, Eckhard Koch

Abstract only

365

0.00 €

 

Mode of action and bacterial determinants involved in the biocontrol activity
of Bacillus subtilis towards fungal and bacterial diseases of cucurbits

Houda Zeriouh, Diego Romero, Laura García-Gutiérrez, Antonio de Vicente, Alejandro Pérez-García

Abstract only

366

0.00 €

 

Biological control of the agriculturally important weeds of southern Russia
from the genera Cynanchum and Vincetoxicum

Natalia Zhemchuzhina, Marina Kiseleva, Alina Alexandrova, Elena Bilanenko, Dana Berner, Tamara Kolomiets

Abstract: Micromycetes strains were isolated from herbarium samples of weeds Cynanchum
acutum and Vincetoxicum funerbe collected in the Krasnodar region a number of
phytopathogenic. Strains were identified to genus and species by means of classical and
molecular methods. The micromycetes Cercospora punctiformis Sacc. et Roum., Alternaria
alternata (Fr.) Keissl., Alternaria infectoria E. G. Simmons, Fusarium heterosporum Nees et
T. Nees, Fusarium sporotrichioides Sherb., Phomopsis sp., Phoma glomerata (Corda) Wollenw.
et Hochapfel, Botrytis fascicularis (Corda) Sacc., Phoma pomorum sensu auct. NZ and a
Deuterophoma sp. were isolated from Cynanchum acutum tissues with disease symptoms. Fungal
strains from the Vincetoxicum funerbe diseased tissues were identified as Acremoniella atra
(Corda) Sacc., Phoma eupyrena Sacc., Phoma chryzanthemicola Hollos, Fusarium oxysporum
E. F. Sm. et Swingle, Nigrospora oryzae (Berk. et Broome) Petch, Curvularia geniculata (Tracy
et Earle) Boedijn, Dendryphiella vinosa (Berk. et M. A. Curtis) Reisinger, Chalaropsis
(Ceratocystis) sp., Alternaria sp., Cladosporium sp., Botrytis cinerea Pers., Gilmaniella humicola
G. L. Barron, Verticillium dahliae Kleb. The phytopathogenic properties of the isolated
micromycetes were tested in the laboratory on the leaflets of plants. The fungi Acremoniella atra
(Corda) Sacc. and Phoma chryzanthemicola Hollos. were revealed as the most perspective
potential agents for the biological control of Cynanchum acutum and Vincetoxicum funerbe.
Severe symptoms of damage caused by Cercospora punctiformis Sacc. et Roum. on C. acutum
were noted in the Krasnodar region around Taman. It is possible this fungus also can be used as a
biological control agent.

367-371

5.00 €

 

Lichen-associated bacteria antagonistic to phytopathogens and their potential
to accumulate polyhydroxyalkanoates

Ilona Gasser, João Vieira de Castro Junior, Henry Müller and Gabriele Berg

Abstract: Bacteria are known to produce polyhydroxyalkanoates (PHA) as a storage substance,
which has properties similar to those of petroleum-derived Polypropylene. Therefore, it is
important to find PHA producing bacteria, which cope with industrial demands. Among
terrestrial ecosystems, the highly active lichen-associated bacterial communities are expected to
be a bio-resource for PHA-producers. Bacteria associated with the lichens Peltigera canina,
Lobaria pulmonata, L. immixta, L. virens and Pseudocyphellaria aurata, collected from different
European countries, were isolated and tested for their ability to antagonize the phytopathogenic
fungi Rhizoctonia solani and Verticillium dahliae. Antagonists were subsequently screened on
their ability to produce PHAs by applying a multiphasic approach. In a first step, a cultivation
independent method was developed to determine the occurrence of gene phaC within the
microbial community of different lichens. Using cultivation-dependent techniques, bacterial
isolates from different lichens were tested on PHA accumulation in vitro employing a plate assay.
In addition, the presence of the PHA synthase gene phaC was determined using PCR analysis.
This study indicates that the thalli space of lichens contains a remarkable and very interesting
population of PHA-producing bacteria, and more studies should be conducted to understand
much better the interaction and function of these bacteria in lichens as well as their potential for
biocontrol strategies. In conclusion, lichen habitats are an excellent source for PHA-accumulating
bacteria.

375-379

5.00 €

 

Volatile organic compounds of plant-associated bacteria
to reduce microbial contamination on clean room textile

Martin Aichner, Lisa Oberauner, Stefan Liebminger, Michael Fürnkranz, Gabriele Berg

Abstract: Since the appearance of multi-drug resistant pathogens, it is a significant issue to find
new innovative antibiotics that can solve this problem. Source for new antimicrobials are
naturally occurring antagonists like plant endophytes. Bacterial plant endophytes have to protect
their niche from other bacteria by producing antibiotics. Natural antagonistic endophytes from
pumpkin and mistletoe were tested against the most common pathogens in clean rooms in order
to identify antagonists that produce new antibiotics. The focus was on VOCs (volatile organic
compounds); gaseous antibiotics emitted by bacteria, which could demonstrate a potent weapon
against pathogens. Clean room textile is intended to hinder particles and microbes to contaminate
the clean room environment. There is a great demand for new routes of decontamination of clean
room equipment and garments. We could demonstrate for the first time that selected antagonist
showed a high activity against clean room derived pathogens and that VOC-producing
antagonists were found to inhibit the growth of Stenotrophomonas maltophilia on clean room
textiles.

381-384

5.00 €

 

Biocontrol under salinated conditions using Stenotrophomonas strains
Christoph Stephan Schmidt, Mohamadali Alavi, Gabriele Berg

Abstract: The genus Stenotrophomonas is of high medical, ecological and biotechnological
interest due to the versatility of the different species. Root colonisation and plant growth
promotion by Stenotrophomonas rhizophila DSM14405T in different crop species and at different
salinities were investigated. Plant growth promotion was most significant in solanaceous crops
(tomato, sweet pepper). In non-sterile systems and ambient humidity, colonisation of aboveground
plant parts was strongly dependent on plant species; epiphyllic populations on tomato
were 4-5 orders of magnitude higher than epiphyllic populations on sweet pepper and cotton.
Rhizosphere populations were uniformly high irrespective of plant species (104 CFU/g root fresh
weight). However, in sweet pepper they declined sharply from 104 to 101 CFU/g root fresh
weight with increasing soil salinity in non-sterile soil (0-1% NaCl). Rhizosphere populations
were higher (~108 CFU/g FW) and the decline with salinity less pronounced in sterile
(autoclaved) soil. A similar decline with salinity could be observed in the above-ground
populations. Although population sizes where lower, plant growth promotion by S. rhizophila
DSM14405T was more pronounced in non-sterile soil than in sterile soil. Only there the effect
was consistent across all salinities so that a linear regression model with S. rhizophila
DSM14405T as significant growth promoting factor could be fitted. The greater effect in nonsterile
soil points to an indirect plant growth promotion effect of S. rhizophila DSM14405T,
possibly via the elimination of deleterious components of the rhizosphere flora.

385-390

5.00 €

 

Biological control agents for combating soil-borne pathogens in Egypt
Martina Köberl, Christin Zachow, Henry Müller, Elshahat M. Ramadan, Rudolf Bauer, Gabriele Berg

Abstract: SEKEM is an Egyptian initiative and a Fair Trade company, where biologic dynamic
agriculture has been practiced for more than 30 years. Medicine, which is produced from
ecologically grown medicinal plants, was developed and is available worldwide. However, the
cultivation of plants is more and more affected by soil-borne pathogens, which leads to
significant yield losses. An environmentally friendly and sustainable solution of the problem is
the introduction of biological control agents (BCA). Through the introduction of BCAs, the
vitality and the natural biodiversity of the soil can be restored. To develop a specific biocontrol
strategy for the SEKEM farms, microorganisms were isolated from rhizosphere and endorhiza of
medicinal plants (Matricaria chamomilla, Calendula officinalis and Solanum distichum) as well
as from Egyptian soil, and were screened for their antagonistic potential towards soil-borne
phytopathogens. Promising biocontrol strains were genotypically characterized and identified.

391-395

5.00 €

 

Antagonistic endophytes from mistletoes as bio-resource to control plant as well
as clean room pathogens

Gabriele Berg, Kathrin Hartenberger, Stefan Liebminger‚ Christin Zachow

Abstract: Viscum album is a hemiparasitic shrub on a wide range of wood species. The bacterial
and fungal communities of Viscum album subsp. album and three different host species (Malus
domestica, Juglans nigra and Acer tataricum) were analysed by cultivation dependent methods.
Endophytes were isolated from leaves and seeds of Viscum album as well as from branches of the
host trees on five different growing media. The isolated endophytes were screened for
antagonistic effects i) against plant pathogens (Alternaria alternata, Botrytis cinerea,
Phytophthora infestans, and Sclerotinia sclerotiorum), and ii) against clean room inhabitants or
pathogens (gram- positive bacteria: Staphylococcus epidermidis, Propionobacterium acnes,
Paenibacillus polymyxa, Geobacillus stearothermophilus, Bacillus pumilus; gram-negative
bacteria: Stenotrophomonas maltophilia, Escherichia coli, Pseudomonas aeruginosa; fungi:
Verticillium dahliae, Aspergillus niger, Candida albicans) by dual culture assay. Beside the high
proportion of antagonistic isolates against both groups in general, we found similarities but also
clear differences between parasite and host. Mistletoes, especially the seeds, contained a higher
antagonistic potential than the host plants. Plant-associated endophytic microorganisms from
parasitic plants are an interesting bio-resource to control plant pathogens but also clean room
inhabitants/pathogens.

397-400

5.00 €

 
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