First Report of Sclerotinia sclerotiorum Causing Sclerotinia Blight on Peanut (Arachis hypogaea) in Northeastern China

Peanut, Arachis hypogaea L., is an important source of vegetable oil and protein in China with a planting area of 5 million ha and annual production of 16.2 million metric tons. In September of 2012, typical symptoms of Sclerotinia blight were first observed on peanut in Shuangcheng, Heilongjiang Province, China. Approximately 50% of the plants in a field were infected. Symptoms began as a chlorotic wilt on the foliage and developed into necrosis of basal stems and developed very quickly in the field. In advanced stages of the disease, stems and branches became bleached and eventually died. White, fluffy mycelium and black irregular sclerotia (3.5 to 5.4 mm diameter) were observed on the infected stems. Infected branches and pegs were shredded, and most pods dropped on the soil during harvest. To isolate the causal agent of the disease, sclerotia were collected from the field. Twenty sclerotia were surface disinfected in 1% NaOCl for 3 min, rinsed three times with sterile water, placed on potato sucrose a...