Identification and fungicides sensitivity evaluation of the causal agent of cobweb disease on Lyophyllum decastes in China

Abstract

Abstract Background: Cobweb disease is a fungal disease that often occurs in the cultivation and production of edible fungi, which can harm a variety of cultivated edible fungi and cause serious losses. Cobweb disease is considered to be one of the four most serious fungal diseases in edible fungi. Symptoms suspected of cobweb disease were found during the cultivation of Lyophyllum decastes mushrooms. The objective of our study was to identify the cobweb pathogen and screen out the effective fungicides, so as to provide a reference for the comprehensive prevention and control of velvet mushroom cobweb disease. Results: The causal agent for this cobweb disease was isolated from symptomatic samples and was found to be Cladobotryum mycophilum based on morphological characteristics, phylogeny (ITS, RPB1, RPB2 and TEF1-α) and the cultural characteristics of two isolates on PDA and MEA medium. Results of pathogenicity tests also supported the conclusion that C. mycophilum is the pathogen responsible for this condition. The antibacterial effect of Prochloraz-manganese chloride complex, Trifloxystrobin and tebuconazole, and Difenoconazole among the tested fungicides is remarkable, with EC50 being 0.076 μg/mL, 0.173 μg/mL and 0.364 μg/mL respectively. These fungicides have good control effect, low toxicity, and have good application potential on L. decastes. Conclusion: First report of cladobotryum mycophilum causing cobweb disease of Lyophyllum decastes in China.