不同抗病性小麦品种上白粉菌吸器发育超微结构研究

利用电镜技术对不同抗病性小麦品种上白粉菌吸器发育及相应寄主细胞变化的超微结构进行了研究，并对吸器的Ca2+－ATP酶活性及几丁质的分布进行了细胞化学定位分析。结果表明，小麦白粉菌（Blumeriagraminisf．sp.tritici）成熟吸器在内部结构上类似一个代谢活跃的菌丝细胞，有大量的线粒体和多聚核糖体；Ca2+－ATP酶主要被定位在寄主质膜及病菌核膜上；随吸器的不断发育，吸器外膜厚度增加，同时Ca2+-ATP酶活性增强。几丁质均匀地分布在吸器壁上，其含量随吸器的成熟而增加。在不同抗病性小麦品种上，吸器细胞核最先退化，然后是线粒体的液泡化和多聚核糖体的解聚。中抗寄主细胞内的吸器普遍退化较早，相当一部分在吸器中心体阶段已解体。此外，高感寄主表皮细胞与叶肉细胞之间有发达的胞间连丝;而且在吸器形成后，能比中抗寄主细胞更快地增殖和聚积大量与能量代谢、物质合成及分泌活动有关的细胞器。

ULTRASTRUCTURAL STUDIES ON HAUSTORIA DEVELOPMENT OF BLUMERIA GRAMINIS F.SP.TRITICI

Ultrastructural and cytochemical studies on haustorial development ofBlumeria graminis f. sp. tritici in wheat cultivars with different resistances were conducted inthis paper.The results showed that the ultrastructure of matural haustorium looked like aactive hypha cell, with a nucleus, a great amount of mitochondria and polyribosmes;Ca2+ -ATPase was localized mainly on the plasmic membrane lf host cell and the nuclear membrane of fungal cell; As the haustorium developed, the extrahaustorial membrane became thick and its Ca2+ -ATPase activity was enhanced sharply; Chitin contributed in allwall of haustoria and accumulated as maturing.The first sign of degradation ofhaustorium was the nuclear degeneration, and then the vacuolation of mitochondria andthe disappear of polyribosomes.Contrast to resistant host, there was abundantplarmodesmata between the epidermal cell and mesophyll cells, and as long as the primaryhaustorium present in the epidermal cell, the proliforation of organelle happened more rapidly in susceptible hosts than in moderate-resistant ones.The mechanism of haustorialdegeneration and haustorial functions were also discussed here.