LAUSR

White mold of common bean caused by Sclerotinia sclerotiorum is a serious disease in temperate and subtropical regions. The present study evaluated the effects of culture filtrates of Purpureocillium lilacinum on S. sclerotiorum under in vitro and in vivo conditions at the concentration of 75% of culture filtrates. The mycelial growth, sclerotia formation, myceliogenic and carpogenic germination of S. sclerotiorum were prevented by 100, 100, 93.5 and 90%, respectively. Lipid peroxidation and cell membrane permeability of S. sclerotiorum mycelia were increased, while oxalic acid content was decreased compared to the control at 75% of the filtrates. Application of the culture filtrates at 75% significantly reduced the disease severity by 83.3% under greenhouse conditions. Besides, the filtrate enhanced the activities of phenylalanine ammonia-lyase (PAL), polyphenoloxidase (PPO) and peroxidase (POD) in common bean plants. The nuclear magnetic resonance (NMR) measurements of the filtrate revealed that its major compounds are the peptides leucinostatins H and K.