Abstract: Sclerotinia diseases caused by Sclerotinia sclerotiorum are a group of soil borne fungal diseases that occur on a variety of crops worldwide and cause severe losses in China.The survival of sclerotia in the soil was critical to the epidemiology of these diseases and was targeted in disease management strategies.This study explored the effects of micro-environmental factors,including soil types,soil moisture,temperature and oxygen level,on the sclerotium survival of S.sclerotiorum in the soil as reflected on the germination rate on PDA plates,and analyzed the composition and relative richness of micro-organisms in the soils after these treatments via high through-put sequencing of bacterial 16s rDNA and fungal ITS.Results revealed that the sclerotium survival of S.sclerotiorum was significantly affected by temperature and soil moisture,but the effects of soil types were insignificant.Incubation at 35℃ and low oxygen conditions of sclerotia of S.sclerotiorum in moist soil resulted in 100% death after 2-4 weeks.The composition and richness of micro-organisms in the soil surrounding the sclerotia differed significantly after incubation under different temperatures and oxygen levels for 4 weeks.Generally,high temperature and low oxygen increased the richness of bacteria in the moist soil,particularly bacteria in the phyla of Firmicutes and Actinobacteriota.The relative abundances of Bacillus and Talaromyces under high temperature treatments were significantly higher than those under low temperature treatments.The relative abundance of Clostridium under low oxygen treatments was significantly higher than that under normal oxygen treatments.The findings from this study shed a light on the new approach to management of Sclerotinia diseases via manipulating soil micro-environmental conditions and soil microbe community.

Key words: manipulation of soil micro-ecosystem, Sclerotinia sclerotiorum, soil microbe community, biological control