First report of peanut pod rot caused by Neocosmospora vasinfecta in northern China.

From 2006 to 2010, peanut (Arachis hypogaea) pod rot became more prevalent in northern China, especially in the Sha River drainage area. The incidence of pod rot ranged from 30 to 100%. Typical symptoms were black rot of the pods, but no obvious morphological abnormality of the aboveground parts of infected plants was observed. Brown or black spots appeared on many pods when initially infected and then all peanut pods became black and rotten. The same fungus was isolated from 54 surface-disinfested lesions (85.2% of all lesions) on potato dextrose agar (PDA) media. One isolate, designated as HBXLb, was chosen for further characterization. In culture, both anamorph and teleomorph were present. Mycelia of the fungus grew quickly (colonies were 3.2 cm in diameter in 3 days) and became white and floccose on PDA at 28°C. The hyaline, elongated-to-cylindrical conidia aggregated on the slimy heads of conidiogenous cells that developed on undifferentiated hyphae after incubation for 3 to 4 days. Conidial sizes va...