First Report of Nigrospora oryzae Causing Brown/Black Spot Disease of Kiwifruit in China

China is the world’s leading kiwifruit producer (Belrose 2016). In September 2016, brown/black spot disease was found on leaves and fruit peel in several kiwifruit orchards in Taishun County, Zhejiang Province and Liupanshui City, Guizhou Province. Diseased leaves and fruit exhibited small irregular brown to black spots (1-2 mm), which exapanded (3-5 mm) and became necrotic with age. Affected leaves became blighted by the fall. Ten orchards in each city were investigated, and approximately 45% of trees were symptomatic in Taishun and Liupanshui (Fig. 1 A-C). Symptomatic tissues of twenty typical infected leaves and fruit were cut into 4-5 mm pieces, surface-sterilized, rinsed three times in sterile distilled water, and cultured on 1.5% potato dextrose agar (PDA) with streptomycin and tetracycline. Petri dishes were incubated at 25°C under a 12-h light / dark cycle. Hyphal-tip from the growing edge of colonies cultured for 3 days at 25°C was transferred to PDA to obtain pure cultures. Fungal colonies were ...