黑龙江省水稻穗褐变病病原菌的分离与鉴定

Isolation and identification of pathogen causing rice panicle browning in Heilongjiang province

摘要:

【背景】黑龙江省水稻穗褐变病发生较普遍，可造成减产和稻米的品质下降。【目的】明确黑龙江省水稻穗褐变病的主要致病菌。【方法】从不同水稻产区采集水稻穗褐变的病样，进行病原菌组织分离和纯化，根据柯赫氏法则确定致病的病原菌，用形态学和分子生物学相结合的方式进行病原菌种类鉴定。【结果】分离出4种主要的菌，进行致病性测定表现出与田间自然发病一致的症状；经形态特征与rDNA ITS序列分析将4种病原菌鉴定为禾谷镰孢菌(Fusarium graminearum Schwabe)、链格孢[Alternaria alternata (Fr.) Keissler]、稻黑孢霉(Nigrospora oryzae Petch)、黑附球菌(Epicoccum nigrun Link)；不同年度间病原菌的优势菌存在差异。【结论】黑龙江省水稻穗褐变病原真菌的鉴定可为开展病害防治工作提供参考。

Abstract:

[Background] The occurrence of?rice panicle browning disease is more common in Heilongjiang province, and it can reduce production and quality of rice. [Objective] To identify the pathogen of rice panicle browning in Heilongjiang province. [Methods] Samples of?rice panicle browning were collected from different rice producing areas. The pathogens were isolated. The pathogens were confirmed pathogenicity according to Koch’s postulates, and identified by morphologic and molecular biological characteristics. [Results] Four isolates were obtained. The symptoms of rice panicle inoculated by the four fungi were similar to that observed under natural conditions. Based on morphologic characteristics and rDNA ITS sequences analysis, four pathogens were identified as Fusarium graminearum Schwabe, Alternaria alternata (Fr.) Keissler, Nigrospora oryzae Petch and Epicoccum nigrun Link. Dominant pathogens could change in different years. [Conclusion] The identification of pathogenic fungi causing rice panicle browning in Heilongjiang province could be references to develop disease management strategies.