中文摘要：

嵩草属（Kobresia Willd．）植物是多年生草本植物，草质柔软、营养丰富，家畜喜食。大多数嵩草植物是青藏高原高寒草甸的主要建群种，其良好生长对维持青藏高原的生态平衡起着重要作用。嵩草属植物主要分布在北半球，共有70种，其中59种分布在中国（主要分布在青藏高原东部）。由于环境及人为影响，我国嵩草草地面临草地退化、载畜能力下降等严峻问题，而且嵩草属植物大多是无性繁殖，对环境变化及不良环境适应性较弱。目前，对嵩草属植物的分子系统发育关系及其适应性研究尚未见报道。本文探索其种内遗传多样性、遗传结构、系统发育关系及种子特性，旨在为进一步研究高寒草甸生态系统的结构、功能及演化提供依据。主要结果如下：

英文摘要：

The genus Kobresia Willd. is the dominant perennial sedge on the Tibetan Plateau and has high nutri- tional quality preferred by livestock and important ecological functions such as water resource conserva tion, river system and regional climate regulation, and regional biodiversity maintenance. Kobresia spp. can be found in the alpine mountains of the northern hemisphere and include about 70 species, with 59 reported throughout China which are mainly distributed in east of the Tibet Plateau. However, Kobresia pastures are confronted with environmental degradation and decreased carrying capacity due to natural and anthropogenic impacts, and seldom research studied the Kobresia species of the Tibetan Plateau on their phylogenetic relationship and adaptation in details, in part because of the difficulty in accessing this cold, harsh, and remote region. Vegetative growth is the dominant means of reproduction for the Kobresia spp.and the substantial vegetative growth can reduce the genetic diversity and render populations with disadvantages to buffer the changing and extreme conditions. It is necessary to protect the genetic diversity of Kobresia and understand how they thrive in a harsh environment. In the present study, the genetic diversity, genetic structure, and seed characteristics of Kobresia species were studied in order to provide theory and technical references for understanding the mechanisms of adaptation and evolutionary history among the Kobresia accessions collected from the Tibetan Plateau.