Studies on Biological Characteristics of Fruit Rot Pathogen—A New Muskmelon Disease in Liaoning Province

The pathogen of muskmelon fruit rot was isolated from the samples of muskmelon from Liaoning Province.The casual agent was identified as AG-4 HGI of Rhizoctonia solani by the studies on morphology,pathogenicity,anastomosis groups and rDNA-ITS.The pathogenic biological characteristics of muskmelon fruit rot were studied in this paper.The result showed that the best medium for mycelial growth was Muskmelon juice culture medium.The temperature ranged for mycelial growth was 5-40 ℃,28 ℃ was the optimum;the best pH was 7.The effect of light on mycelial growth was not evident.Mycelial growth was in favor of soluble starch and Peptone.The ideal sclerotia formation was at 25 ℃,pH 6-8,Richard culture medium.The suitable carbon source for the formation of sclerotia was Sorbitol.The beneficial nitrogen source for the formation of sclerotia was KNO 3.The sclerotia could germinate in 10 kinds of nutrition.The proper temperature was 15-40 ℃,and 28 ℃ was the optimum.Dark condition was conductive to sclerotium germination.The best carbon source and nitrogen source for sclerotium germination are Malt Sugar and Peptone.Mycelial lethal temperature was 50 ℃,10 min.The sclerotia lethal temperature was 53℃,10 min.