兰州百合枯萎病病原菌鉴定及罹病组织超微结构观察

为明确引起甘肃省兰州百合主产区百合枯萎病的致病镰孢菌种类,对从百合主产区枯萎病罹病植株上分离纯化的4株镰孢菌株进行形态学鉴定、分子生物学鉴定以及致病性测定,同时利用电子显微镜对尖孢镰孢菌Fusarium oxysporum侵入百合鳞片后的细胞超微结构进行观察。结果表明:4株镰孢菌菌株经鉴定分别为尖孢镰孢菌、茄病镰孢菌F. solani、三线镰孢菌F. tricinctum和燕麦镰孢菌F. avenaceum。4株镰孢菌菌株的致病力由强到弱的顺序依次是尖孢镰孢菌、燕麦镰孢菌、茄病镰孢菌、三线镰孢菌;尖孢镰孢菌侵入后,鳞片细胞壁、细胞质膜和细胞核结构被破坏,细胞核附近出现大量线粒体,细胞中淀粉粒数量减少。表明尖孢镰孢菌是兰州百合枯萎病防治的重点防控对象。

Identification of pathogens causing Fusarium wilt of Lanzhou lily, and the observation of cell ultrastructures in the infected bulb scales

To clarify Fusarium species causing the wilt disease of Lanzhou lily in the main producing region of Gansu Province, four Fusarium strains were isolated and purified from lily with wilt symptoms, and morphological characters and molecular sequence analysis as well as pathogenicity test were performed. In addition, the cell ultrastructures in the lily bulb scales infected by F. oxysporum were also observed with electronic microscope. The four strains were identified as F. oxysporum, F. solani, F. tricinctum and F. avenaceum, respectively. The pathogenicity of these strains decreased in the following order: F. oxysporum, F. avenaceum, F. solani, F. tricinctum. The electronic microscope observation revealed that the cell walls, cytoplasmic membranes and nuclei in lily bulb scale were damaged by infection of F. oxysporum. It was also found that lots of mitochondria appeared near the nucleus, and plasmolysis occurred in the infected cells.The sever damages suggested that the prevention and control of Fusarium wilt should have the top priority in the edible Lanzhou lily production region.