不同抗性的榨菜在芜菁花叶病毒感染后细胞超微结构的研究

Studies on Cytopathological Ultrastructure of Three Different Disease Resistance Tuber Mustard Varieties Infected with Turnip Mosaic Virus

超薄切片观察表明，在三种感染芜菁花叶病毒的榨菜叶肉细胞内均发现有各种形状的内含体和病毒粒子的存在。内含体形状有风轮状、束状、管状、环状和板状聚集体，且不同抗性的榨菜品种细胞内所含的内含体数量、种类及所占的比例亦不同，抗性较弱的９０－１４９榨菜品种叶肉细胞内内含体数量较多，以管状及环状内含体所占比例为多，束状及风轮状内含体所占比例较少；抗性较强的９０－１３９榨菜品种叶肉细胞内内含体数量较少，且以束状及风轮状内含体所占比例较多，环状及管状内含体所占比例较少。而抗性中等的９０－１４６榨菜品种叶肉细胞内内含体数量及所占比例介于上述两者之间。病毒粒子也以易感病的９０－１４９榨菜叶肉细胞内含量最多，均以束状或拟晶格状存在。此外感病初期细胞内线粒体及粗面内质网数量有不同程度的增多，且以易感病的品种叶肉细胞内这些细胞器增加明显，但健康植株内以抗性较强的品种含这些细胞器较多。随着病毒症状的发展，叶绿体畸形，肿大，基质消失，外膜破裂直至解体。

ltrathin sections of leaf tissues of three tuber mustard varieties infected with Turnip MosaicVirus were examined in the electron microscope.The results revealed that the aggregates of fila-mentous virus particles,which always distributed near vacuole membrane and cytoplast in meso-phyll cells,were seldom found.The inclusions including pinwheels(or bundles)laminated ag-gregates and circles(or tubers)were appeared in mesophyll,epidermal and xylem parenchymascells of all diseased leaves,while the contents and the proportions of three types inclusions weredifferent in different disease resistant tuber mustard varieties,The contents of inclusions in meso-phyll cells of the sensitive tuber mustard(90-149)were more than those in resistant tuber mus-tard(90-139).Meantime the sensitive had high proportions of circles or tubers and low propor-tions of pinweels or bundles,while contrasted to the resistant.The contents and the proportionsof inclusions in the medial disease resistant variety(90-146)were bewteen above two varieties。The results also showed that the virus particles in the sensitive variety are more than those in theresistant variety.In addition,cells infected at early period were characterized by a voluminous cy-toplasm containing a high ribosome content,hypertrophied endoplasmic recticulum and mitochon-dria.The sensitive variety had more those celluiar organelles than resistant variety,but in thehealth plant the sensitive variety contained less those cellular organelles than those of resistant va-riety.As the disease developed,a considerable degeneration of cellular constituents was ohserved,chloroplasts and mitochondria were gradually disrupted and cells filled with debris of these or-ganelles and with remanants of the disease-associated inclusions.