Biological control of postharvest diseases by Pantoea agglomerans 59-4 on garlic bulbs
Hyo Jin Kim, Yong Ki Kim, Tack Soo Kim, Kyung-Suk Park, and Wan-Hae Yeh
Abstracts of 27th International Horticultural Congress & Exhibition (IHC 2006), August 13-19, 2006, COEX (Convention & Exhibition), Seoul, Korea. 494 pages.
2006
บทคัดย่อ
Biological control of postharvest diseases by Pantoea agglomerans 59-4 on garlic bulbs
To screen for potential biocontrol agents against the postharvest disease of garlic caused by Penicillium hirsutum, a total of 1292 isolates were isolated from the rhizoshere or rhizoplane of Allium species.From these the S59-4 isolate was selected as a potential biocontrol agent when using an in vivo wounded garlic bulb assay.When the spore suspension (105 spores/ ml) of P. hirsutum was co-inoculated with a cell suspension of S59-4 (108 cfu/mL) isolate on wounded garlic, the isolate showed a highly suppressive effect on disease development.The isolate was identified as the bacteria Pantoea agglomerans(Pa59-4) through use of the Biology system, the MIDI system and 16S rDNA analysis.In order to investigate the population dynamics of Pa59-4 on the application site of garlic cloves, two antibiotic markers, pimaricin and vancomycin (25 mg/ml) were selected.Bacterial density of Pa59-4 on wounded garlic cloves increased continuously both under room temperature and low temperature conditions until 30 days after application.On intact garlic cloves density of Pa59-4 increased until 15 days after application and thereafter decreased continuously.The culture media selected for mass-production of Pa59-4 were LB and TSB media, were selected.A by-product of the bio-fungicide formulated by mixing white carbon and bacterial culture filtrates of Pa59-4, suppressed growth of garlic blue mold by 40 to 50%.In addition, Pa59-4 showed in vitro inhibitory effects against various postharvest disease of citrus fruits, apples, onions, lettuces and carrots.In particular Pa59-4 showed strong inhibitory effects against Penicillium digitatum, Aspergillus niger, Sclerotinia sclerotiorum and Geotrichum candidum.