【摘要】 通过电子显微镜的观察指出,从生长季节到寒冬时期,抗寒性较强的温州蜜柑(宫川)叶片细胞中叶绿体的淀粉粒含量明显地减少,但线粒体的数量显著地增多;其液泡在抗寒锻炼过程中产生活跃的内吞作用,吞噬和消化细胞质,提高液泡液溶质的浓度。与此同时,抗寒性较弱的甜橙(冰糖橙),其淀粉粒含量不减少,线粒体数量不增加,液泡的内吞作用发生得比较晚,活跃性与频率也较低。讨论了这些细胞结构的变化与植物抗寒性的关系。更多还原

【Abstract】 A comparative study on the ultrastructural adaptive changes in the leaf cells of two species of citrus ( C. unshiu and C. sinensis ) with diffe-rent cold resistance from growing season to hard winter period was carried out by use of electron microscopy. The following experimental results ha-ve been obtained.1. During the growing season,the palisade and spongy mesophyll cells contain a big central vacuole and many chloroplasts and some mitochon-dria in cortical cytoplasm (Fig. 1,3,4). The chloroplasts store many starch grains, and some-times the division multiplication of chloroplasts can be observed ( Fig. 2 ) .2. During hardening period of autumn and winter, the stored starch grains of chloroplasts were markedly decreased ( Fig. 9 ) , but the number of mitochondria was increased ( Fig. 10 ), and the vacuoles produced en-docytosis and so a lot of cytoplasmic material have been transfered into vacuoles ( Fig. 5-8 ) in the leaf cells of satsuma orange ( Citrus unshiu Mo-re ), winch’s cold hardiness is stronger.3. In the leaf cells of less cold hardiness "Bing-tang" orange ( Citrus sinensis ) hardened under low temperature of autumn and winter,the starch grains of chloroplasts were not decreased (Fig. 11-14) ; and the mi-tochondria were not also increased; and the endocytosis of vacuoles was coming later and its frequency was lower than that of the stronger har-diness satsuma orange.4. It is discussed that the changes of the ultrastructural adaptation in leaf cells are in relation to the development of the cold resistance in citrus trees during hardening period of autumn and winter.更多还原