Mycotoxins from Botrytis cinerea can be developed as herbicides due to their high herbicidal bioactivity. Conidial suspension and hyphae from isolate BC4 of B. cinerea was treated with ultraviolet radiation and chemical mutagens. Three isolates with higher herbicidal activity were selected out from total 86 mutant isolates. The result of HPLC analysis showed that the herbicidal content in the three isolates were much higher than that in the wild isolate. Four fractions from the metabolite of the mutant isol...