新疆阿尔金山国家级自然保护区5种大帽藓叶表面及叶尖的微形态结构

Micromorphological structure of leaf surface and apex of five Encalypta Species(Encalyptaceae,Musci)from Altun Mountain Nature Reserve in Xinjiang Province

运用光学显微镜和扫描电镜,对新疆阿尔金山的5种大帽藓属(Encalypta Hedw.)植物的叶表面和叶尖进行了微形态观察.结果表明:高山大帽藓(E.alpina Smith)中肋粗壮,达于叶尖并突出成细长毛尖,叶腹面的分叉疣多呈马蹄形,严密地覆盖在叶表面,疣上具粗糙纹饰,叶背面具不规则乳突,排列疏松;尖叶大帽藓(E.rhaptocarpa Schwgr.)叶先端急尖,中肋粗壮,具长毛尖,疣的中下部两两相连,形成分叉疣,疣表面具纵向纹饰;剑叶大帽藓(E.spathulata Müll.Hal.)中肋突出叶尖形成透明毛状长尖,毛尖细胞长,疣在基部分叉丛生;西藏大帽藓(E.tibetana Mitt.)先端钝或急尖,无毛尖,中肋达于叶尖下终止,叶背腹表面疣疏松,空隙大,疣上有层层叠加状纹饰;钝叶大帽藓(E.vulgaris Hedw.)先端圆钝,中肋在叶先端前消失,疣粗糙,疣上有层层叠加状纹饰,具粘液.5种植物叶片的背、腹面具不同的分叉粗疣,疣的大小、形态、着生位置、疣上的纹饰各不相同;这些细微特征可作为大帽藓属属下分类的依据之一.

The leaf surface and apex of five species of Encalypta Hedw.from Altun Mountain Nature Reserve in Xinjiang were observed by optical microscope and scanning electron microscope（SEM）.The results showed that：the leaves of E.alpina Smith.have thick costae up to the tip with long hair-points and mostly U-shaped papillae closely arranged on the ventral surface with rough ornamentation on the ventral surface,while irregular papillae loosely presented on the dorsal surface;the leaves of E.rhaptocarpaSchwgr.have acute apex with long hair-points and papillae joining with each other at the middle-lower part with striped ornamentation on the surface;the leaves of E.spathulata Müll.Hal.have hyaline and long hair-points and stellate papillae at the base;the leaves of E.tibetana Mitt.are muticous with costae ending below the obtuse or acute apex and possess loose papillae with ornamentation on the ventral surface layer by layer;the costae of E.vulgaris Hedw.leaf ends below the obtuse apex and the papillae are rough and mucous with overlapping ornamentation on the surface.The five Encalyptaspecies are able to be separated by the size,position,shape and ornamentation of the papillae on the leaf surface.These micromorphological structures provide reference for taxonomically features at the infrageneric level in this genus.