Ingredient analysis and bioassay of the toxin of Fusarium oxysporum f. sp. cubense.

Ingredient analysis and bioassay of the toxin of Fusarium oxysporum f.sp.cubense race 4 were conducted by HPLC and GC/MS.Ingredient analysis showed that there were 7 components in the toxin of Fusarium oxysporum f.sp.cubense,whose calculus percentage of chromatographic peak were 5.81%,5.94%,6.31%,2.80%,3.42%,73.34% and 2.37%,respectively.Among them,the sixth absorption peak,fusaric acid,was the major ingredient of the toxin and played the most important role in pathogenesis.The other 6 also promoted the wilt of the host.The bioassay showed that the effect of toxin on the wilt of banana seedlings was more significant than that of the commercial fusaric acid under the condition of the same concentration.This toxin had obvious toxic effect on different varieties of banana seedlings and other crops.It was non-host specificity and the toxic effect intensity became stronger with the increase of its concentration.