狗尾草属5种植物叶片的形态特征

Leaf Morphological Characteristics of Five Setaria Species

摘要:

为了解狗尾草属(Setaria Beauv.)植物的叶片形态特征，采用石蜡切片法和徒手切片法观察5种狗尾草属植物的叶片形态结构。结果表明，5种狗尾草属植物叶表皮的解剖特征较一致，叶表皮细胞长度、气孔器大小、叶厚、角质层厚度等性状在种间存在显著差异，其中长细胞形状、垂周壁深浅、气孔器副卫细胞的形状和刺毛数量可以用来区分种类。叶片性状的相关分析表明，叶片气孔密度与气孔长度以及气孔宽度呈显著负相关，泡状细胞厚度与角质层厚度以及上表皮厚度呈显著正相关。根据禾本科叶表皮特征的演化趋势，狗尾草(S. viridis)最原始，金色狗尾草(S. glauca)和大狗尾草(S. faberii)较进化，皱叶狗尾草(S. plicata)和莩草(S. chondrachne)最高级。这些为狗尾草属植物分类学和系统演化关系提供资料。

Abstract:

In order to understand the leaf morphological characteristics of leaves in Setaria, the anatomical structure of leaves in five Setaria species were studied for by using paraffin section and the freehand section methods. The results showed that the anatomical characteristics of leaf epidermis in five species were similar. The length of long cell and short cell, stomatal size and thickness of leaf and cuticular layer had significant differences among five species. And the shape of long cell, pattern of anticlinal wall, shape of stomatal subsidiary cells, and number of prickle hairs could be used to identify species. The correlation analysis showed that there were significant negative correlations between stomatal density and stomatal length, stomatal width. Besides, the thickness of bulliform cells had significant positive correlations with thickness of cuticular layer and adaxial epidermis for 5 species. According to leaf epidermal traits in Gramineae, the evolution trend was in the order of S. viridis → S. glauca and S. faberii → S. plicata and S. chondrachne. These could provide basic data for the study of systematics and evolution in Setaria.