Identification of a new pathogen of apple ring blight in Zhaotong
Apple is one of the most important economic crops in China,and ring rot is an important disease of apple,which can cause fruit rot and economic loss.In order to identify the pathogen of ring rot disease in Zha-otong apple fruit,the infected fruits were collected from 5 apple production areas in Zhaotong,and the patho-gen was isolated and identified through separation and purification of the lesion tissue,pathogenicity detection,morphological observation and molecular biological identification.The results showed that the pathogen isola-ted from the infected fruit was Nigrospora oryzae,a new pathogen different from Botryosphaeria berengeri-ana and B.berengeriana f.sp.piricola.In PDA culture,the bacterial colonies of this pathogen were floccu-lent with white color of front and back,and developed air mycelium and fast growth.At late stage of culture,the both sides of the colony gradually turned gray to black.The mycelium was septate,light brown,and branched with short conidial peduncle.The conidia were black,unicellular and spherical.Under the condition of temperature at 17-26 ℃ and the average relative humidity at 93％-97％,the disease developed rapidly with obvious symptoms on the healthy fruits inoculated with this pathogen.The whole fruit was decomposed with sour taste in the later stage,which was consistent with the symptoms of naturally occurring apple ring rot in the later stage.It was the first time in China to report that the fungus of rice Melanospora caused damage to apple fruit.The results of this study can provide help for effective prevention and treatment of apple ring rot.
apple ring rotpathogen isolationmolecular identificationMelanospora oryza
万方数据
维普
