Screening for Nidula species as novel biological control agents to Sclerotinia sclerotiorum

11 out of 39 isolates of Nidula spp from Yunnan province showed clear inhibition zone in dual culture test with S. sclerotiorum. Greenhouse trials with cultural filtrate of BNF71 and BNF137 showed reduction disease incidence by 98.8% and 86.1%, inhibition lesion enlargement by 99.7% and 97.9%, respectively. Wheat bran culture preparation of BNF71 was also effective insuppression of rapeseed seedling stem rot caused by S. sclerotiorum, with disease decreased by 85.2%. In addition to the highly antagonism against S. sclerotiorum, BNF71 and BNF162 were able to inhibit Aspergillus niger, A. flavus, Pythium ultimum, Rhizoctonia solani and Drechslera sorokiniana in vitro. Nidula isolates possessed high xylanase activity, and BNF134 exhibited significant exo-chitinase activity.