บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Bacteria colonizing melon fruit surface act as biocontrol agents to postharvest disease pathogens.

Y. Wang, L. Xu, Y. Mastuda and H. Toyoda.

Journal of Plant Pathology Volume 90 (2, Supplement) August 2008, Book of Abstract, 9th International Congress of Plant Pathology, August 24-29, 2008 Torino, Italy,. 507 pages.

2008

บทคัดย่อ

Bacteria colonizing melon fruit surface act as biocontrol agents to postharvest disease pathogens.

The present study was conducted to select antagonistic bacteria that superficially colonize melon fruits and to clarify their suppressive functions against fungal pathogens, aiming at developing practical biocontrol agents for post-harvest diseases of melon fruits. Bacteria colonizing melon fruits were obtained by printing fragmented pericarps o­nto LB culture medium. Antifungal activitywas screened by pair-culturing with fungal pathogens, and identified o­n the basis of DNA sequence alignments and conventional bacterial characteristics; o­ne was identified as Bacillus amyloliquefaciens EXWB3, and the others B. subtilis EXWB1, EXWB2 and EXWB4. Four isolates expressed significant antifungal activity to eight postharvest pathogens, Botrytis cinerea, Alternaria alternata, Fusarium oxysporum, Aspergillus niger, Trichothecium roseum, Penicillium sp. and Cladosporium sp. Of the antagonistic isolates tested, EXWB1 was most effective, suppressing conidial germination of B. cinerea, A. alternata and F. oxysporum and inducing darker cell walls and abnormal conidial shape. The isolate secreted some bio-surfactants, which helped the sprayed bacteria to stick to the hydrophobic fruit surface. Melon fruits treated with EXWB1 retained high levels of sugar, vitamin C and organic acids even after inoculation with A. alternaria and F. oxysporum. Additionally, EXWB1-26 treatment suppressed the respiration increase and ethylene production that were typical in pathogen-inoculated fruits, and limited both fungal growth and expansion of the necrotic lesions produced by pathogen inoculation. Thus, the present study provides a promising biological agent to suppress fungal pathogens causing postharvest market diseases of fruit crops.