长春花叶片发育过程中气孔密度和气孔指数的动态变化

Dynamic changes of stomatal density and stomatal index during the leaf development in Catharanthus roseus

对长春花叶片近轴面和远轴面上的气孔密度和气孔指数在不同发育阶段的动态变化进行了研究。结果表明:在各个发育阶段,近轴面上的气孔以叶脉两侧居多,远轴面上的气孔则在整个叶片上均匀分布。将一个枝条上的10对真叶按发育顺序界定为10个发育阶段,即从枝条的顶端到基部,分别将第10、第9、第8……第1节位的叶片定义为第1、第2、第3……第10发育阶段。长春花叶片长度在开始的前3个阶段增加迅速,在第3阶段时叶片长度可达(4.5±0.4)cm。在开始的前3个阶段,表皮细胞主要进行细胞分裂和细胞扩大。从第4阶段开始,表皮细胞的分裂和扩大基本停止。从第4阶段到第8阶段,气孔密度和气孔指数基本保持稳定。在最后2个阶段即第9和第10阶段,无论是近轴面还是远轴面都出现气孔指数和气孔密度骤增的现象。

The present paper focused on dynamic changes of stomatal density and stomatal index during the developmental stage of Catharanthus roseus leaves. It was found that at all developmental stages, stomata mainly distributed along veins on adaxial surface, while uniformly distributed on abaxial surface of the whole blade. The ten pairs of leaves numbered from bottom to top in one shoot were divided into ten developmental stages which were numbered from top to bottom, e. g. leaves in the 10th nod were in stage Ⅰ, the rest might be deduced by analogy. Due to cell divi- sion and cell enlargement during the first three stages, the leaves of C. roseus grew rapidly. In stage Ⅲ ,the leaf length could reach （4.5±0.4） cm. Cell division and cell enlargement basically stopped at stage IX. Stomatal density and stomatal index kept stable from stage IX to stage Ⅶ. In the last two stages-stage Ⅸ andX, stomatal density and stomatal index increased abruptly.