青藏高原一新特有属——异型株属及其传粉模式(英文)  

A New Qinghai-Tibet Plateau Endemic Genus Sinoswertia and Its Pollination Mode

作　　者：何廷农[1] 刘尚武[1] 刘建全[1,2] 

机构地区：[1]中国科学院西北高原生物研究所高原生物进化与适应重点实验室,青海西宁810001 [2]兰州大学生命科学院草地农业生态系统国家重点实验室,甘肃兰州730000

出　　处：《植物分类与资源学报》2013年第3期393-400,共8页Plant Diversity

基　　金：Key Project of the National Basic Research Program of China(2007FY110100)

摘　　要：胚胎学和分子证据表明广义獐牙菜属的异形花组应该独立为一个新属。在重新检查该属唯一种在各居群的形态变化时,发现该物种具有异形植株和异形花;前一性状在以前的研究中被忽略了,同时还发现该物种主要是采用闭花受精结实,这一繁殖特点可能是对青藏高原极端环境生存适应的结果。这些特征明显不同于獐牙菜属的其余种和相关属。综合其它证据讨论了该种的系统位置,认为其与花锚属有最近的亲缘关系,这一物种独特的形态性状和系统位置支持其独立为属,并正式描述和发表这一新属——异型株属。但是必需指出的是,广义獐牙菜属排除这一物种后,分子证据表明其还是一个复系属。分类上处理这种由于快速物种多样化和性状趋同进化导致的复系属仍面临巨大的挑战,还有待今后更详细的研究。Available data from both embryological and molecular studies of the monotypic section Heteranthos within the genus Swertia s. 1. suggested that this taxon should be erected as a separate genus. We examined morphological variations of the only species across multiple populations and found that it has two types of individuals and one type contains both large and small flowers while the other only small flowers. However, all small and most large flowers set seeds through a cleistogamous pollination mode, which may have evolved in response to the reproductive adapta- tion to the arid habitats of the Qinghai-Tibet Plateau. However, this pollination mode is different from the outcrossing breeding system observed for the other Swertia species. Dimorphic plants and flowers distinguish this species from the other Swertia species and related genera. We further discussed the systematic position of this species based on the comprehensive data and the current data support its close relationship with Halenia. The morphological distinct- ness and systematic position of this species from all comparisons justified its generic status. We here place this spe- cies in a new genus Sinoswertia, and describe and illustrate it. However, after excluding this species, Swertia s. 1. is still polyphyletic based on the molecular evidence. The taxonomic treatment of this polyphyletic genus possibly due to the recent radiative diversification and convergent evolution poses an extreme challenge at the present and pends further detailed studies.

关 键 词：异型株属 异型植株 异型花 传粉式样 

分 类 号：Q948[生物学—植物学]