不同海拔高度上两种蒿属植物叶表皮结构比较研究

Comparative study on the leaf epidermal structure of two Artemisia species at different altitudes

对小五台山地区不同海拔的两种蒿属植物长梗米蒿(Artemisia giraldii Pamp.var.longipedunculata Y.R.Ling)和南牡蒿(A.eriopoda Bge.)的叶表皮结构进行了观察和分析。A.giraldii和A.eriopoda的叶背腹两面均有T-或Y-型毛,两种植物表皮细胞形状为不规则或多角型,垂周壁式样有波状和平直两种;不同海拔的A.giraldii和A.eriopoda叶片两面都有气孔分布,A.giraldii的气孔复体为无规则四细胞型(Anomotetra-cytic)和不等型(Anisocytic),偶见有无规则型(Anomocytic);A.eriopoda多为不等型,稀见无规则四细胞型。发现同种植物叶两面的气孔密度和气孔指数随海拔升高都有变化;而叶表皮形态、气孔复体结构与被毛类型等在同种内变化不大。这表明叶表皮、气孔复体和表皮毛类型等在一定程度上代表了物种属性,而气孔密度与气孔指数的变化体现了蒿属植物在不同海拔环境中,对多种生态因子共同作用的特殊适应性。

The leaf epidermal structures of two species of Artemisia L. , Artemisia giraldii Pamp. var. longipedunculata Y. R. Ling and A. eriopoda Bge. collected from different altitudes of Xiaowutai mountains were examined and analyzed. The trichomes of A. giraldii and A. eriopoda were both T-or Y-form, present on the upper and the lower epidermis. The epidermis cells on both surfaces were irregular or polyangular, and the anticlinal walls were undulance and straight. The stomatal complex occured on both surfaces of A. giraldii and A. eriopoda from different alti- tudes. Anomotetracytic, anisocytic type and some anomocytic type stomatal complex were found in A. giraldii while anomotetracytic type, anisocytic type and some anomocytic type stomatal com- plex were found in A. eriopoda. The results indicated that with increasing altitude, the stomatal density and index changed while the leaf epidermal structures, stomatal complex and the type of epidermal hairs did not change significantly in the same species. This suggests that, in a certain extent, stomatal structures, stomatal complex and epidermal hairs represent the character of the species, and the variation of stomatal density and index show Artemisia＇s adaptability under gradient altitude environment and diversified ecological factors.