Induced Resistance by the Cell-Wall Released Elicitors from Fusarium oxysporum f.sp.niveum and F. oxysporum f.sp. cubense against Fusarium Wilt of Watermelon
Two cell -wall released heat -solubilized elicitors from Fusariwn oxysporum f.sp.niveum and F. oxysporum f.sp. cubense were tested for their eliciting activity on watermelon seedlings against fusarium wilt. The elicitor from F. oxysponan f. sp. niveum induced lignification of host cells, but stronger lignification was induced by the elicitor from F. oxysporum f.sp. cubense. The two elicitors also aroused remarkable increase in PPOD, POD, PAL activities of watermelon seedlings, but the elicitor from F. oxysporum f.sp. niveum acted more quickly than that from F. oxysporum f.sp. cubense. The watermelon seedlings showed enhanced resistance to the fusarium wilt after treatment with elicitor from F. oxysporum f.sp. cubense, but higher resistance was induced by the elicitor from F. oxysporum f.sp. niveum.