小麦雪霉叶枯病菌侵染过程的细胞学研究

采用电镜技术研究了小麦雪霉叶枯病菌(Gerlachia nivalis)侵染过程的细胞学特征。电镜观察发现,分生孢子萌发产生的芽管由孢子细胞壁内层延伸而成;病菌侵入寄主体内后,胞间菌丝先在寄主细胞间扩展,随后胞间菌丝侵入坏死的寄主细胞,形成胞内菌丝;胞间菌丝和胞内菌丝在形态结构上无明显差异。在病菌扩展过程中,寄主细胞发生了一系列的病理变化,并最终坏死消解,寄主细胞的变化可能与病菌分泌的毒素有关。

CYTOLOGY OF INFECTION OF GERLACHIA NlVALIS ON WINTER WHEAT

The infection of Gerlachia nivalis on the leaves of winter wheat was examined with electron microscopy. The results from observation showed that the germ tube was produced by protrusion and extension of inner layer of conidiospore wall when spores germinated, After invasion of the pathogen into host, intercellular hyphae extended at first between host cells, then infected dead host cells and produced intracelllular hyphae in host cells. It was found that there was no difference in morphology and structure between two kinds of hyphae. Several conidia were formed on each conidiogenous cell succesively by endoblastic phialidic means. During extension of intercellular hyphae, a series of pathological changes occurred in host cells, and the host cells died and were digested finally, probably resulting from the toxin secreted by the pathogen.