含笑花被片发育和衰老过程中细胞超微结构的变化

以含笑花被片为材料,研究了含笑花发育和衰老进程中细胞超微结构的动态变化。组织化学实验表明,花被片薄壁细胞具有淀粉复合物,其数量多少在花被片发育和衰老过程中呈动态变化。在透射电镜下,Ⅰ时期花被片基本薄壁组织细胞中淀粉复合物极少,可见少量叶绿体;随着花蕾的生长发育,Ⅱ时期至Ⅲ时期花被片基本薄壁组织细胞中淀粉复合物、线粒体、溶酶体等逐渐增多;Ⅳ时期花被片已展开,其淀粉复合物逐渐减少或消失,细胞中的线粒体、溶酶体等细胞器出现不同程度解体;Ⅴ时期花被片萎凋时,淀粉复合物甚少,细胞壁严重弯曲、变形。在扫描电镜下,从顶面观察花被片表皮细胞,可见Ⅰ时期的表皮细胞紧密、光滑;Ⅱ时期至Ⅲ时期花被片表皮细胞表面纹饰结构清晰,同时,基本薄壁组织细胞中颗粒状淀粉复合物随着花被片的发育其数量逐渐增多;Ⅳ时期花被片展开时,表皮细胞垂周壁的条纹上、表皮细胞间隙、气孔孔口可见淀粉复合物,细胞中淀粉复合物逐渐减少且消失;Ⅴ时期花被片已萎凋,表皮细胞塌陷、细胞间隙出现裂痕,细胞中淀粉复合物消失,有少量棉絮状物质。对含笑花被片细胞超微结构的变动与衰老的关系进行了讨论。

Changes of cell microstructure during development and senescence in perianth of Michelia figo (Lour.)Spreng.

Dynamic changes of cell microstructure during development and senescence in perianth of Michelia . figo were studied. Experimental study of histochemistry showed that there were starch-similar compounds in ordinary parenchyma cells of perianth of M. figo and starch-similar compounds varied in numer dynamically during development and senescence in perianth of M. figo. There were very few starch-similar compounds and few chloroplasts contained at stage I in ordinary parenchyma cells of perianth of M. figo, mitochondria and lysosome were increased at stage Ⅱ and Ⅲ in perianth cells with bud growth and development. Perianth at stage Ⅳ had unfolded and starch-similar compounds gradually decreased and disappeared, mitochondria and lysosome in cells disintegrated in different degree. When perianth withered at stage Ⅴ , starch-similar compounds were less, cell wall seriously bended and deformed. Epidermis cells were tight and smooth at stage Ⅰ by SEM. Ornamentation on Epidermis cells was distinct and the quantity of starch-similar compounds in ordinary parenchyma cells were more and more with the growth and development of the perianth at stage Ⅱ and stage Ⅲ . When the perianth unfolded at stage Ⅳ , starch-similar compounds were discovered on ornamentation and interspaces of epidermis cells and stomata's orifice, but starch-similar compounds in cells gradually decreased and disappeared. When perianth withered at stage Ⅴ , epidermis cells collapsed, gaps appeared between epidermis cells, starch-similar compounds in cells disappeared and some flocculent substances were left. The relationship between cell microstructure changes and senescence in perianth of M. figo was discussed.