低温胁迫下两种七叶树苗木超微结构的比较  

A Comparative Study on Ultra-structure of Aesculus chinensis and A.pavia Seedling Top Bud Under Cold Stress

作　　者：杜艳[1] 喻方圆[1] 甘习华[1] 沈永宝[1] 

机构地区：[1]南京林业大学森林资源与环境学院,江苏南京210037

出　　处：《南京林业大学学报（自然科学版）》2007年第3期111-114,共4页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：江苏省农业三项工程项目[S(01)56]

摘　　要：以七叶树（Aesculus chinensis Bunge）和红花七叶树（A．pavia L．）1年生苗木为材料，经不同低温处理后，用透射电子显微镜观察其顶芽基部组织细胞超微结构的变化。结果表明：七叶树顶芽基部组织细胞死亡的基点温度和冷冻时间分别为-18℃条件下冷冻72h、-30℃条件下冷冻24～72h和-70℃条件下冷冻24h。此时细胞超微结构表现为大部分细胞内含物降解，空泡化，细胞质解体，少数细胞虽未解体，但核膜已变得模糊不清；红花七叶树顶芽基部组织细胞死亡的基点温度和冷冻时间分别为-18℃条件下冷冻168h、-30℃条件下冷冻168h和-70℃条件下冷冻24h。此时细胞超微结构表现为细胞出现质壁分离现象，细胞结构不清晰，细胞质解体，核凝聚，质膜上含较多电子致密的黑颗粒。从细胞超微结构的比较可以看出，红花七叶树的抗寒能力明显大于七叶树。Top buds of one-year-aged seedlings of Chinese buckeye（Aesculus chinensis Bunge） and red buckeye（A, pavia L. ）were placed in di{{erent cold stress conditions, and the ultra- structural changes o{ these top bud cells were compared under the transmission electron microscope. The results showed that the lethal temperature and duration time of top bud in Chinese buckeye was -18℃ within 72 h,-30℃ within 24~72 h, and -70℃ within 24 h. The ultra-structure of top buds in Chinese buckeye at the lethal condition was shown as follows. most of cells were degraded and vacuolated. The cytoplasm was disintegrated. Although a few of cells were not disintegrated, their nuclear membrane could not be seen clearly. The lethal temperature and duration time of top buds in red buckeye was -18℃　within 168 h,-30℃ within 168 h, and -70℃ within 24 h. The ultra-structure of top buds in red buckeye at the lethal condition was shown as follows： The plasmolization was found in cells. Cell structure was blurred. The cytoplasm was disintegrated. Cell nucleus was condensed and many black particles were found in plasma membrane. It could be found from the comparison of ultra-structure in two species that the cold-resistance of Red buckeye was better than that of Chinese buckeye.

关 键 词：七叶树 红花七叶树 超微结构 抗寒性 

分 类 号：S718.42[农业科学—林学]