不同发育时期板栗叶肉细胞中叶绿体淀粉和质体小球的变化     

刘林  李明泽  王怀中  刘铁梅  李芸  韩世明  李春奇 《果树学报》2010,(1)

对板栗在春季折叠的幼叶和平展生长的幼叶、夏季成熟叶和秋季老叶的叶肉细胞中的叶绿体做了透射电镜观察,结果表明,春季折叠的幼叶的叶绿体中不含淀粉和质体小球,平展生长的幼叶含淀粉粒没有质体小球;夏季成熟叶的叶绿体中淀粉最多并出现极少量质体小球;秋季衰老叶的叶绿体中淀粉粒减少直至消失,质体小球数量激增;有的质体小球在叶绿体内被一层膜包围并降解。根据染色特点,可将质体小球分为黑色和灰色2类。淀粉减少及质体小球增多与叶绿体功能衰退相关。  相似文献   

Licht- und elektronenmikroskopische Untersuchungen an Blättern mehrerer Kartoffelsorten nach Salzgaben zu verschiedenen Entwicklungsstadien     

Sabine Bruns  Charlotte Hecht-Buchholz 《Potato Research》1990,33(1):33-41

Zusammenfassung Ver?nderungen in der Blattfeinstruktur als Folge von in verschiedenen Entwicklungsstadien einsetzender Versalzung wurden bei den Kartoffelsorten Hansa und Clivia mehrmals im Vegetationsablauf untersucht. Die Chloroplasten reagierten am deutlichsten auf den Salzstre\: ein Abbau der Granastapel, Schwellungen der Thylakoide, mehr und gr?\ere Plastoglobuli sowie St?rkeakkumulation wurden beobachtet. ‘Hansa’ schien zu Beginn der Vegetationsperiode salzempfindlicher zu sein, da sich hier st?rkere strukturelle Ver?nderungen zeigten als bei der Sorte Clivia, deren Chloroplasten erst gegen Ende der Vegetationsperiode Beeintr?chtigungen aufwiesen.

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Summary The leaves of the potato cultivars Hansa and Clivia were examined by light and electron microscopy after salt treatment. Salt was applied once: a week after emergence, at the beginning of tuber formation, or during tuber development. The salt solution (conductivity 12 mS/cm) contained NaCl and Na₂SO₄, and was administered to the water capacity of the pots. Leaf samples were taken at three different stages of vegetative development (Figure 1). In leaf sections examined by light microscopy, salt stress resulted in a rounding off of cells, smaller intercellular spaces and a reduction in chloroplast number. With the electron microscope salt-induced changes were more marked in the chloroplasts than other organelles. Salt reduced the numbers and depth of the granastacks and caused a swelling of the thylakoid. Changes in ultrastructure were already apparent before the occurrence of other symptoms in the leaf. The observed changes in the chloroplasts of plants treated with salt were alwas greater in the palisade parenchyma than in the spongy parenchyma (Figure 3a, 3b). The cultivars Hansa and Clivia reacted differently to salt. At the start of the vegetative period ‘Hansa’ (Figure 2b, d) appeared more sensitive than ‘Clivia’ (Figure 2c) with greater ultrastructural changes. By the last sampling date ‘Clivia’ was showing the greatest effects (Figure 4). Large starch grains in the chloroplasts indicated disturbed transport of assimilates. Often there were no grana, but severely swollen thylakoids, usually with disintegrating membranes. Changes in the chloroplasts, especially in the thylakoids, as established by microscopy, presumably affected photosynthetic and assimilative performance.

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