| 摘要: |
| 【目的】探讨并比较猴樟（Cinnamonum bodinieriLevl）和芳樟（C.camphoraL.(linalool-type)）在低温胁迫过程中叶肉细胞超微结构的变化，揭示樟树低温胁迫的响应机制，为北方地区耐寒樟树的引种提供理论依据。【方法】以猴樟和芳樟的1年生幼苗为试材，采用室内低温处理的方法，对2种樟树在0 ℃下处理12，24，48 h及在－5，－10 ℃下处理24 h，取样并采用透射电子显微镜观察樟树叶肉细胞超微结构的变化。【结果】低温胁迫对2种樟树叶肉细胞超微结构均产生了一定影响。适当低温胁迫，导致2种樟树叶肉细胞器中叶绿体结构首先发生膨大变形，淀粉粒出现降解现象，液泡内含物增加。随着胁迫时间的延长和温度的降低，过度的低温胁迫导致叶绿体结构分解，淀粉粒消失，甚至出现质壁分离、细胞器崩溃降解现象。相同低温条件下，猴樟叶绿体结构遭到破坏的程度及淀粉粒降解速度均小于芳樟，至-10 ℃胁迫24 h时，芳樟叶绿体、细胞核等器官均已遭到严重损伤，而猴樟细胞结构尚能维持完整。【结论】低温胁迫下，猴樟叶肉细胞中叶绿体等细胞器的稳定性大于芳樟，其对低温的适应能力相对较强。 |
| 关键词: 低温胁迫 超微结构 樟树 |
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| 基金项目:河南省重点科技攻关计划项目(0624070035) |
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| Comparison of leaf blade ultra-structures of two camphor varieties under cold stress |
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| Abstract: |
| 【Objective】The ultra-structure changes of Cinnamonum bodinieri Levl and C.camphora L. (linalool-type) leaves cells under different artificial low temperatures were explored.【Method】One-year-old seedlings of two camphor varieties were probed into in the condition of 0 ℃ for 12, 24,and 48 hours,and -5 ℃ and -10 ℃ within for hours before the ultra-structure changes of these leaves cells were compared using the transmission electron microscope.【Result】The results showed that ultra-structures of mesophyll cells of two camphor varieties changed obviously after low-temperature stress.The shape of chloroplasts changed firstly,starch grains decomposed slightly and cell inclusion increased in the low-temperature stress.C.bodinieri Levl had more stable chloroplasts and later decomposed starch grains might be due to its greater capacity for cold tolerance than linalool-type under low-temperature stress.After 24 hours stress of -10 ℃,cell organelles of linalool-type were damaged badly,but the cell structure of C.bodinieri Levl remained undamaged.【Conclusion】The stability of mesophyll cells such as chloroplast organelles was greater than that of C.camphora L.(linalool-type) under the same low temperature conditions.Thus,its ability to adapt to the low temperature was stronger. |
| Key words: low temperature stress ultra-structure camphor tree |
