【摘要】 以烟草品种三生烟 (N .tabacumcv .Samsun)为测试寄主 ,采用酶联免疫检测实验 (TAS ELISA)和电镜观察的方法 ,在温室条件下研究了马铃薯Y病毒 (PVY)和马铃薯X病毒 (PVX)复合侵染所引起的寄主症状和病毒浓度变化的特点、不同条件下复合侵染时病毒浓度的变化规律以及复合侵染对寄主细胞超微结构的影响。结果表明 ,PVY/PVX在烟草植株内发生了协生作用 ,PVY是协生病毒 ,PVX是被协生病毒。与单独侵染相比 ,PVY和PVX的复合侵染使烟草植株症状明显加重。PVY在复合侵染植株中的浓度与在单独侵染植株中相比 ,没有明显的变化 ,而PVX在复合侵染植株中的浓度明显高于在单独侵染植株中的浓度。这种现象不受PVY株系、处理季节和接种次序的影响。但是 ,不同PVY株系、不同处理季节或不同接种次序对PVY/PVX协生作用中PVX浓度的影响程度存在着一定的差异。电镜观察表明 ,与不接种病毒或单独侵染的植株相比 ,受复合侵染的烟草叶片细胞超微结构发生了明显的病理学变化。细胞肿胀 ,叶绿体、线粒体等细胞器受到严重损伤 ,细胞质内有风轮状、薄片状的内含体 ,由于在细胞质中常常有大量纤维状的PVX病毒粒子聚集体存在 ,这意味着PVX浓度的增加可能是在复合侵染的细胞中病毒大量繁殖的结果。更多还原

【Abstract】 The viruses titer and the ultrastructure of infected cells of tobacco host (N. tabacum cv. Samsun), doubly infected by potato virus Y necrosis strain (PVY N) and potato virus X (PVX), were studied under greenhouse conditions. The results indicated that PVY N and PVX interact synergistically, and tobacco plants which doubly infected by PVX and PVY N could greatly increased symptom severity as compared with that induced by individual virus. As determined by triple antibody sandwich enzyme linked immunosorbent assay (TAS ELISA), the titer of PVX in tobacco leaves infected by both PVY N and PVX was up to 9.10 times higher than the plants infected by PVX only. No significant differences in PVY N titer were detected between singly and doubly infected plants. The enhancement of PVX titer in doubly infected plants was evident in greenhouse and was not influenced by virus strains, tested seasons, intervals between PVY N and PVX inoculation. Sections of doubly infected leaves were examined with an electron microscope. It was found that cells contained pinwheels and large masses of PVX like particles, pinwheels and laminate inclusion, or all three structures, most of them were swollen, and their chloroplast and other organella were damaged heavily. This suggests that doubly infected cells be involved in the enhancement phenomenon, which seems the result of an increase in the amount of PVX synthesized in them.更多还原