Characterization of marine Pseudomonas spp. antagonist towards three tuber-rotting fungi from Jerusalem artichoke, a new industrial crop

摘要

The aim of this study was the isolation, characterization, and selection of Pseudomonas spp. with antagonistic activity against Jerusalem artichoke tuber rot disease during storage. Ten pathogenic fungi were isolated from rotting tubers and classified in seven genera based on morphology and the part sequences in the ITS analysis. The marine Pseudomonas spp. strain JK2, isolated from mud in South China Sea, exhibited high antifungal activity against Aspergillus tamari (M10), Fusarium solani (M9), and Aspergillus fumigatus (M2). JK2 was identified as Pseudomonas spp. based on morphological, physiological and biochemical methods as well as 16S rDNA analysis. Seven days after inoculation the radii of the inhibition zone (mm) of M2, MO and M10 were 10.5 +/- 1.2, 6.5 +/- 0.15, and 13.0 +/- 0.75, respectively, compared to the sterilized medium as control. Transmission electron microscopy showed that, compared with the normal hyphae, the fungal hyphae treated with strain JK2 had injury in the cell wall. Thus, JK2 had a significant fungicidal effect on the three pathogenic fungi. To our best knowledge, this is the first report of biocontrol agent for storage disease of Jerusalem artichoke. 2012 Elsevier B.V. All rights reserved.