山定子抗褐斑病菌侵染的细胞学研究
Cytological Study on Resistant Malus baccata Leaves Infected by Diplocarpon mali

为揭示山定子抗褐斑菌机制，运用透射电子显微技术，观察苹果褐斑菌（Diplocarpon mali）侵染不同抗性材料的细胞超微结构变化特点。结果表明，接种3 d和5 d，山定子细胞核逐渐凝集，叶绿体和线粒体等细胞器逐渐降解，而接种相同时间的‘富士’细胞超微结构变化程度较山定子严重。接种5 d，‘富士’病健交界以及距病健交界2 cm、4 cm的细胞核凝集和细胞器结构畸形程度均比山定子严重，且距发病部位越近则‘富士’和山定子叶片细胞核凝集及线粒体降解程度越严重。表明，接种部位山定子细胞超微结构变化较‘富士’推迟，与发病部位相邻的未发病部位细胞死亡程度较‘富士’轻，推测山定子的抗性可能与细胞超微结构变化的推迟和减弱相关。
In order to reveal the resistant mechanism of Malus baccata to Marssonina leaf blotch of apple, transmission electron microscope (TEM) was used to observe ultrastructural changes in different materials caused by Diplocarpon mali. At 3 d and 5 d after inoculated, nuclei were gradually condensed and chloroplasts as well as mitochondria were gradually degraded in M.baccata leaves, but the degree of these changes was slighter than that in Malus domestica. At 5 days after inoculated (dai), at the junction region between the diseased and non diseased, from the junction about 2 cm and 4 cm in M.domestica nucleus condensation and cellular structural deformity were more serious by comparing with M.baccata. These results indicated that ultrastructural changes in inoculated site of M.baccata were delayed, and from diseased region to non diseased region, the degree of ultrastructural changes in M.domestica leaves was more serious than that in M.baccata. These might suggest that resistant mechanism of M.baccata probably be related to its delay and weakness of ultrastructural changes.