The elicitation effect of pathogenic fungi on trichodermin production by Trichoderma brevicompactum

The effects of six species of phytopathogenic fungi mycelia as elicitors on trichodermin yield by Trichoderma brevicompactum were investigated. Neither nonviable nor viable mycelia of Botrytis cinerea, Alternaria solani, Colletotrichum lindemuthianum, and Thanatephorus cucumeris demonstrated any elicitation on the accumulation of trichodermin. However, the production of trichodermin was increased by the presence of viable/nonviable Rhizoctonia solani and Fusarium oxysporum mycelia. The strongest elicitation effect was found at the presence of nonviable R. solani. At the presence of nonviable R. solani, the maximum yield of trichodermin (144.55 mg/L) was significantly higher than the Control (67.8 mg/L), and the cultivation time to obtain the maximum yield of trichodermin decreased from 72 h to 60 h. No difference of trichodermin accumulation was observed by changing the concentration of nonviable R. solani from 0.1 to 1.6 g/L. It was observed that the optimum time for adding nonviable R. solani is immediately after inoculation. The diameter of T. brevicompactum mycelial globule after 72 h cultivation with nonviable R. solani elicitor was smaller than that of the Control.