多花黄精五个居群叶片的比较解剖学研究

Leaf comparative anatomy of Polygonatum cyrtonema from five populations

关键词:  多花黄精  叶片  居群  比较解剖学

Key words:  Polygonatum cyrtonema  leaf  population  comparative anatomy

摘要:

利用石蜡切片技术、叶表皮离析法和电镜扫描技术,对多花黄精五个居群的叶片进行了比较解剖学研究。观察发现:多花黄精五个居群的叶肉细胞中均具有内含针晶束的异细胞,叶表皮细胞为长方形、不规则形或椭圆形,垂周壁一般为平直和弧形; 有的居群下表皮有单细胞表皮毛分布。在扫描电镜下,角质层纹饰多为鳞片状。结果表明叶表皮特征,如:气孔器大小、气孔器指数、气孔器密度、气孔器分布特征、角质层纹饰及表皮毛的分布等受环境因子影响较大,同种不同居群间有一定差异,而叶肉的构成、内含物(如针晶束)、气孔器类型、表皮细胞形状等具有种间稳定性,可以作为分类的依据。

Abstract:

The comparative anatomy of the leaves of Polygonatum cyrtonema from five populations are studied. The results are as follows:the idioblasts with raphide are common in mesophyll of five populations of P.cyrtonema. The shapes of leaf epidermal cells are rectangle,irregular or oblong and the anticlinal walls are straight and arched. Some populations have unicellular hairs on lower epidermis. The cuticular ornamentation of leaf epidermis is usually scaly under SEM. The result shows that leaf epidermal characters such as size,index,density and distribution of stomatal apparatus,cuticular ornamentation and distribution of epidermal hair in different populations are mostly affected by environment. But some characters such as structure of mesophyll,inclusion(such as raphide),type of stomatal apparatus and shape of epidermal cell show stabilization in species which may be regarded as evidence for division of species.