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Classical and augmentative biological control against ... - IOBC-WPRS

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Appendix 6<br />

showed protein content of 2.7 mg/ml with chitinase activity of 120 IU/ml. High chitinase activity was measured in the culture filtrates of most of the self-fusants (87%) than the parent. Among the<br />

fusants, the strain SFSg 5 produced protein content of 7.8 mg/ml, maximum chitinase activity of 283.3 IU/ml with a two-fold increase as compared to the parent strain. All the self-fusants exhibited<br />

increased antagonistic activity <strong>against</strong> F. oxysporum f. sp. lycopersici than the parent. Maximum inhibition (82%, 80%) of mycelial growth of F. oxysporum was recorded with fusant of SFSg 5, SFSg 1<br />

as <strong>against</strong> 61.1% with PSg. The result implies that, the self-fused Streptomyces griseus resulted in appreciable increase of chitinase production <strong>and</strong> bio<strong>control</strong> activity also the significance of the<br />

protoplast fusion technique, which could successfully be used to develop hybrid strains also for commercial formulation.<br />

Baysal, O., M. Calskan, et al. (2008). "An inhibitory effect of a new Bacillus subtilis strain (EU07) <strong>against</strong> Fusarium oxysporum f. sp. Radicis-lycopersici." PMPP Physiological <strong>and</strong> Molecular Plant<br />

Pathology 73(1/3): 25-32.<br />

destructive disease on tomato (Lycopersicon esculentum Mill.) transplant seedlings <strong>and</strong> the causal organism of crown <strong>and</strong> root rot of tomato plants growing in southern coast greenhouses of Turkey. An<br />

isolate of Bacillus subtilis (EU07) identified by the 16s RNA region code gene was selected as the best antagonist <strong>and</strong> evaluated <strong>against</strong> FORL in vitro studies. Strain EU07 at 106 CFU ml-1 was able to<br />

reduce disease incidence by 75%, when applied as an inoculant. It efficiently inhibited FORL compared to the <strong>control</strong> <strong>and</strong> QST 713 (AgraQuest, Davis, CA) whose inhibition ratio was only 52% in vivo.<br />

R<strong>and</strong>om amplified polymorphic DNA analyses showed b<strong>and</strong>ing (genetic) differences between EU07 <strong>and</strong> QST 713 whereas there were no differences between DNAs of strains that have high homology<br />

to genes involved in the synthesis of antibiotics fengycin, bacillomycin <strong>and</strong> iturin when screened by oligonucleotide primers designed based on sequence information obtained from the NCBI database.<br />

Furthermore, one specific fragment in the EU07 genome showed the highest similarity to YrvN protein by 99% <strong>and</strong> AAA ATPase domain protein (72.2%) after amplifying oligonucleotide primers that<br />

are specific to the N-acyl-homoserine lactonase (HLS) gene as a bio<strong>control</strong> activity marker. These results suggested an effect of EU07 on <strong>control</strong> FORL by YrvN protein as subunit of protease enzyme.<br />

Furthermore, this fragment associated with HLS gene may be a potential molecular marker for selecting effective <strong>biological</strong> <strong>control</strong> agent belonging to Bacillus in order to <strong>control</strong> soilborne pathogens<br />

such as Fusarium, suggesting impairment in FORL invasion by signaling in the plant rhizosphere.<br />

Bernal-Vicente, A., M. Ros, et al. (2009). "Increased effectiveness of the Trichoderma harzianum isolate T-78 <strong>against</strong> Fusarium wilt on melon plants under nursery conditions." Journal of the Science of Food<br />

<strong>and</strong> Agriculture 89(5): 827-833.<br />

BACKGROUND: The use of isolates of the genus Trichoderma to <strong>control</strong> Fusarium wilt in melon plants is one of the most recent <strong>and</strong> effective alternatives to chemical treatments. In this work we have<br />

studied the immobilization of the isolate Trichoderma harzianum T-78 on different carriers as an efficient method to <strong>control</strong> vascular Fusarium wilt of melon in nurseries. Different formulations were<br />

developed: liquids (spore suspension, guar gum <strong>and</strong> carboxymethylcellulose) <strong>and</strong> solids (bentonite, vermiculite <strong>and</strong> wheat bran). RESULTS: The introduction of F. oxysporum resulted in a significant<br />

decrease in seedling fresh weight. The treatments which gave a lesser reduction in weight <strong>and</strong> showing a greater bio<strong>control</strong> effect were the liquid conidial suspension <strong>and</strong> the solid treatments with<br />

bentonite <strong>and</strong> superficial vermiculite. Micro<strong>biological</strong> analyses revealed that the conidial suspension <strong>and</strong> all the solid treatments, except wheat bran, significantly decreased F. oxysporum populations. Of<br />

all the treatments assayed, bentonite produced the greatest decline in the F. oxysporum population. CONCLUSIONS: The most effective treatments <strong>against</strong> Fusarium wilt on melon plants were the solid<br />

treatments bentonite <strong>and</strong> superficial vermiculite. These two treatments gave the greatest plant weight, the lowest percentage of infected plants <strong>and</strong> the greatest T. harzianum population throughout the<br />

assay. (C) 2009 Society of Chemical Industry<br />

Boureghda, H. <strong>and</strong> Z. Bouznad (2009). "Biological <strong>control</strong> of Fusarium wilt of chickpea using isolates of Trichoderma atroviride, T. harzianum <strong>and</strong> T. longibrachiatum." Acta Phytopathologica et<br />

Entomologica Hungarica 44(1): 25-38.<br />

The efficiency of the antagonist species Trichoderma atroviride (strains Ta.3, Ta.7 <strong>and</strong> Ta.13), T. harzianum (Th.6, Th.12, Th.15, Th.16 <strong>and</strong> Th.18) <strong>and</strong> T. longibrachiatum (TL.1, TL.2, TL.4, TL.5, TL.8,<br />

TL.9, TL.10, TL.11, TL.14 <strong>and</strong> TL17) <strong>against</strong> Fusarium wilt (caused by Fusarium oxysporum f.sp. ciceris) was compared using in vitro- <strong>and</strong> in vivo-based bioassay. A significant decrease of both<br />

growth <strong>and</strong> conidia production of the pathogen was obtained compared to the <strong>control</strong>. The highest percentages of diameter colony reduction <strong>and</strong> conidial production were obtained with Ta.13, causing<br />

65.64% reduction in colony diameter (direct confrontation), 48.71% reduction in colony diameter (indirect confrontation), <strong>and</strong> a complete inhibition of conidial production. Once more in direct<br />

confrontation, T. atroviride overgrowth the pathogen colony <strong>and</strong> sporulate above. The seed treatment by Trichoderma spp. isolates before sowing in a soil already infested by the pathogen led to a<br />

significant decrease of disease severity compared to the untreated <strong>control</strong>. The weakest index of disease severity was obtained with Ta.13, which caused 83.92% reduction compared to the <strong>control</strong>. The<br />

most effective isolates in protecting chickpea seedlings <strong>against</strong> the disease were Ta.3, Ta.7 <strong>and</strong> Ta.13 as well as Th.16. The reduction of disease severity was associated with an increase of the vegetal<br />

growth including the stem height as well as the plant fresh <strong>and</strong> dry weights.<br />

129

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