常绿杜鹃亚属云锦杜鹃亚组26种植物叶片微形态特征及其分类学意义

Leaf micromorphological characteristics and taxonomic significance of twenty-six species of subsect.Fortunea,subgen.Hymenanthe(Ericaceae)

通过扫描电子显微镜对隶属于常绿杜鹃亚属(subgen.Hymenanthes)下云锦杜鹃亚组(subsect.Frotunea Sleumer)内的26种植物的叶片表皮特征进行观察,结果表明,26种植物气孔器具有一定相似性,表现为下表皮均有卵圆形或椭圆形气孔器;气孔器散生或聚集有序分布于乳突状或藜状突起之间,气孔器周围有或无间断的条形突起环绕;内外拱盖表面光滑或粗糙;叶表面有或无网状微绒毛;有或无腺体.此外云锦杜鹃亚组下种各成员之间又有明显的区别.因此,云锦杜鹃亚组叶表皮的鳞片,毛被,腺体等,气孔器及其周围纹饰等微形态特征可为分类学提供一定证据.本文的20个种的叶表皮微形态特征属首次报道,根据叶表皮微形态特征,本文给出了这26种杜鹃的分种检索表,并探讨了该亚组下种间亲缘关系及进化趋势,并且还讨论了该亚组的分类学存疑种的分类处理意见.

In this paper,micromorphological characters of leaf epidermis of 26（20 species are first reported） species in subsect.Fortunea Sleumer,subgenera Hymenanthes from China were examined using scanning electron microscopy（SEM）.The twenty-six species are R.fortunei-type,which the stomatal apparatus are ovoid or elliptical,with protuberance and complex ornamentation around.It was showed that the shape and size,scale,gland,foliar trichome and stomatal apparatus and ornamentation of the leaf epidermis varies in the twenty-six species and these characters could be used to identify the species and provide some evidence for phylogenetic relationships of subsect.Frotunea Sleumer.Meanwhile,keys were generated according to micromorphological characters of leaf epidermis and discussed interspecific phylogenetic relationship as well as evolutionary trends.Finally,some taxonomy doubting species were discussed and provided reference applications.