中国早熟禾属植物部分种叶下表皮微形态的研究

通过光学显微镜及扫描电子显微镜对中国早熟禾属20种、6亚种及2变种植物的叶下表皮微形态特征进行了观察, 以明确叶表皮微形态特征在早熟禾属植物中的分类学意义。结果显示：(1)早熟禾属植物的叶下表皮长细胞多为长筒状或纺锤形，少数短筒状，细胞壁波状弯曲或近平直；脉间具有短细胞或缺如；气孔器多数常见，副卫细胞平行形至低圆屋顶形；脉上具有刺细胞或缺如，脉间刺细胞多为缺如；脉上硅细胞单生或对生，椭圆形、肾形、新月形、近方形、长方形边缘波状弯曲或结节形；部分早熟禾属植物叶下表皮存在冠细胞。(2)早熟禾属植物叶下表皮微形态特征在长细胞的形状及其细胞壁的弯曲与否、短细胞的有无及其形状、气孔器的分布与副卫细胞的形状、刺细胞的分布、脉上硅细胞的形状、冠细胞的有无这些方面存在着一定的差异，可为该属植物种间分类提供参考依据。叶表皮微形态证据支持高原早熟禾、细叶早熟禾作为草地早熟禾亚种的处理意见。

Micromorphology of Leaf Abaxial Epidermis of Some Poa Species in China

Micromorphological characters of leaf abaxial epidermis of 20 species, 6 subspecies and 2 varieties of Poa was examined by light microscope and scanning electron microscope, to infer its significance for classification of the genus Poa.The results indicated that: (1) the leaf abaxial epidermis of Poa were characterized by long tubular, fusiform or short tubular long cells with straight or sinuous wall; presence or absence of short cells in intercostal zone; frequent stomata and parallel sided or dome shaped subsidiary cells distributed in intercostal zone; presence or absence of prickle cells in costal zone, absence of prickle cells in intercostal zone; elliptic, reniform, crescentic, subsquare, horizontally elongated sinuous or nodular silica cells distributed solitary or in pairs in costal zone; presence of crown cells in some species. (2) Variations of leaf epidermal features existed at the species level, such as shape and wall thickness of long cells, presence or absence of short cells and its shape, distribution of stomata and shape of subsidiary cells, distribution of prickle cells, and shape of silica cells distributed in costal zone. The micromorphological study revealed that the characters of leaf abaxial epidermis could provide evidences for classification of the genus Poa. Moreover, the evidences of leaf abaxial epidermis confirmed the view that P. pratensis subsp. angustifolia and P. pratensis subsp. alpigena were the subspecies of P. pratensis subsp. pratensis.