Production profile and comparison analysis of main toxin components of Fusarium oxysporum f. sp. sesami isolates with different pathogenicity levels

Abstract

Abstract Fusarium wilt is a critical fungus disease for sesame, which is induced by Fusarium oxysporum f. sp. sesami (FOS). In order to determine the toxin production profiles of the FOS isolates with different pathogenicity levels under various culture conditions, we evaluated the content variation of fusaric acid (FA) and 9, 10-dehydrofusaric acid (9, 10-DFA) produced by the 4 representative FOS isolates. Results indicated that the maximum amount of FA reached to 2848.66 µg/ml in Czapek medium, while 9, 10-DFA was mainly produced in Richard and Low-carbon Richard medium. The concentration of 9, 10-DFA on Richard culture medium varied from 0 µg/ml to 716.89 µg/ml. Of the 5 kinds of culture media, Czapek culture medium was the most conductive to produce FA. FA production was significantly affected by culture medium, culture time, and their interaction (***, P < 0.001). The results suggest that there is no correlation between toxin production and pathogenicity level of FOS isolates. The findings give key information for the mechanism analysis of FOS- sesame interaction and pathogen control.