青海省蕨麻根腐病调查及病原真菌分离鉴定

Investigation of Potentilla anserina root rot in Qinghai province and isolation and identification of pathogenic fungi

蕨麻是我国青藏高原特有的植物资源,近年来根腐病对蕨麻生产构成了一定威胁。2019-2021年6~7月,分别对青海西宁市、海北藏族自治州和黄南藏族自治州等地成株期蕨麻根腐病进行调查,对具有典型症状特征的病样,采用组织分离法和单孢分离法获得病原真菌,以柯赫氏法则对其致病性进行验证;通过形态学和分子生物学等方法对蕨麻根腐病病原真菌进行鉴定。结果表明:蕨麻根腐病具有典型症状特征(黑斑、褐变、软化、腐烂、附着菌丝),病害多发生于蕨麻块根膨大期及收获期;蕨麻根腐病病情分级标准可分为0-5个等级;不同种植年限、不同地区蕨麻根腐病病情存在一定的差异,株发病率和病情指数与种植年限均呈正相关;分离鉴定发现病原真菌均为镰刀菌属(Fusarium),包含锐顶镰刀菌(F.acuminatum)、三线镰刀菌(F.tricinctum)、变红镰刀菌(F.incarnatum)、燕麦镰刀菌(F.avenaceum)、木贼镰刀菌(F.equiseti)和念珠镰刀菌(F.torulosum)。该研究为蕨麻根腐病的诊断及防控提供了基础理论依据。

Juema(Potentilla anserina)is widely cultivated in the Qinghai-Tibet Plateau in China.In recent years,root rot disease has been found to pose a threat to the health and production of Juema.From June to July in 2019-2021,Potentilla anserina root rot in the mature-plant stage was investigated in Xining City,Haibei Tibetan Autonomous Prefecture and Huangnan Tibetan Autonomous Prefecture in Qinghai Province,and samples with typical symptoms were collected and brought back to the laboratory.The pathogenic fungi were obtained by tissue separation and single spore separation,and their pathogenicity was verified by Koch’s rule.The identification of the pathogenic fungi of rhizoma Potentilla anserina root rot was carried out by means of morphological observation and molecular biological identification.The results showed that Potentilla anserina root rot had typical symptoms(black spot,browning,softening,rot,hypha adhesion),and the disease occurred mostly at the root enlargement and harvesting stage.The Potentilla anserina root rot disease can be divided into 0-5grades to determine the severity of the disease.There were some differences in root rot disease among different planting years and different regions.There was some variation in root rot of Potentilla anserina between planting years and regions,with both plant incidence and disease index positively correlated with planting year.The pathogenic fungi were all identified as Fusarium:F.acuminatum,F.tricinctum,F.incarnatum,F.avenaceum,F.equiseti and F.torulosum.This study provided a basic theoretical basis for the diagnosis and prevention and control of root rot of Potentilla anserina.