喜树叶片愈伤组织形成过程的细胞学研究

Cytology Study on Callus Formation of Leaves of Camptotheca acuminate

以喜树叶片为外植体诱导愈伤组织形成，显微结构和超微结构观察表明：喜树叶片置于培养基1d以后即发生细胞分裂，叶片切口处叶肉细胞最早活化分裂，随后分裂逐渐遍及整个培养材料．愈伤组织形成过程中，叶绿体中积累大量淀粉，产生原质体芽和原质体，是叶肉细胞脱分化过程的中间演变阶段．在愈伤组织形成过程中，线粒体、内质网分布于叶绿体及质膜周围，数量较多，内质网为粗面内质网．细胞质在愈伤组织形成过程中逐渐减少，胞间隙在愈伤组织形成过程中逐渐增大，为裂生型胞间隙．

This article aimed to study the callus formation of the leaves. The optical microscope and transmission electron microscope were used in this study. The result shows： The cell division started after the leaves were cultured for one day, the cells in the cut leaf were the first to enter division, then the cell division expanded gradually to the rest of the tissue. During the dedifferentiation of the explant of the Camptotheca acuminata leaves, the number of starches accumulated in the chloroplast, the chloroplast formed proplastid buds and proplastid, which was considered the intermediate stage of the mesophyll cells dedifferentiation. During the process of callus formation, the mitochondrion, rough endoplasmic reticulum distributed around the chloroplast and plasma membrane, they were large amounts of them ih quantity. The cytoplasm gradually reduced during the callus formation and the intercellular space increased gradually, the intercellular space was schizogenous intercellular soace.