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利用光学和电子显微镜,从组织细胞学水平系统研究了冠盘二胞Marssonina coronaria在苹果抗、感病品种叶片上的侵染过程及侵染后寄主细胞的超微结构特征。结果表明:冠盘二胞的侵入和定殖过程可以分为6个阶段:孢子萌发与芽管形成、附着胞形成、侵入细胞角质层、在叶肉细胞内产生吸器、菌丝在叶肉细胞间和细胞内扩展、分生孢子盘形成。随着菌丝扩展,受侵寄主细胞出现细胞壁加厚,细胞壁降解,质壁分离,叶绿体内淀粉粒、嗜饿颗粒积累,叶绿体基粒片层瓦解,线粒体空泡化等现象。在不同抗性的苹果品种上,分生孢子萌发率差别不明显,但芽管分枝率、附着胞形成率和侵入后病菌在不同抗性品种叶片组织内的发育进程具有显著差异。在抗病品种上,病菌侵入时间,角质层下菌丝、叶肉细胞内吸器、分生孢子盘的形成时间推迟,芽管分枝少,胞内吸器少,菌丝生长缓慢,菌丝周围沉积有大量电子致密物。苹果不同品种对冠盘二胞的抗病性表现在抗侵入和抗扩展能力两个方面。
Using optical and electron microscopy, we investigated systematically the infection process of Marssonina coronaria on the leaf of resistant and susceptible varieties of apple and the ultrastructure of the host cells after infection. The results showed that the process of invasion and colonization of placental cells could be divided into six stages: spore germination and germ tube formation, attachment formation, invasion into stratum corneum, generation of inhalers in mesophyll cells, Expansion of cells, conidial disk formation. With the expansion of mycelium, the infected host cells appeared thickened cell wall, cell wall degradation, plasmolysis, accumulation of starch granules and starvation granules in chloroplast, disintegration of mitochondria and mitochondria in chloroplast. The germination rate of conidia on apple cultivars with different resistances was not significantly different, but the developmental rates of shoots, adherent cells and invasion of post invader germs were significantly different among different resistant cultivars. On resistant cultivars, the invasion time of germs, hyphae hyphae, mesophyll cell vacuoles, the formation of mesophyll discs were postponed, germinated branches were less, less endocytosis, mycelial growth was slow, and mycelium was deposited There is a lot of electron density. The resistance of different varieties of apple to TPD is manifested in two aspects: anti-invasion and anti-expansion.