小麦族天然杂种的起源及优异种质创制

小麦族植物具有重要的经济价值，它不仅包含了小麦、大麦等粮食作物，许多还是重要的牧草，如老芒麦、垂穗披碱草、赖草等是川西高原、青藏高原等高寒地区重要的组成牧草。在四川红原，我们发现一些植株高大、叶量丰富、分蘖多、绿期长、耐瘠薄的天然杂种。年限越久，杂种越能表现出抗性（耐瘠薄、耐杂草）优势。这些天然杂种是如何形成的？天然杂种在小麦族物种形成中的作用如何？如何有效利用具有良好牧草性状的天然杂种？本项目针对川西高原发现的一系列天然杂种，通过形态学比较、远缘杂交、核型分析、染色体组组成分析、基因组原位杂交分析、DNA序列分析（细胞核基因、叶绿体基因）等方法探究：（1）天然杂种的形态学和细胞学鉴定（染色体数目、基因组组成）；（2）天然杂种的起源及形成机制；（3）天然杂种在小麦族物种形成中的作用；（4）改良天然杂种，创制牧草性状好、育性高的牧草新种质，为选育牧草新品种奠定材料基础。

Plants in Triticeae have important economic values. It contains not only grain crops such as wheat and barley, but also many important pastures. Elymus sibiricus, E. nutans, Leymus secalinus are important forage species in alpine area of Western Sichuan Plateau and Qinghai Tibet plateau. In Hongyuan, Sichuan, we found a series of natural hybrids with tall plants, abundant leaves, tiller number, long green period and barren. The longer period, the hybrid can exhibit resistance advantage (tolerance, weeds resistant). How are these natural hybrids formed? What is the role of natural hybrids in the formation of Triticeae species? How to effectively use natural hybrids with good herbage traits? In this study, we use morphological comparison, distant crosses, karyotype analysis, genome composition analysis, genomic in situ hybridization analysis, DNA sequence analysis to study: (1) morphological and cytological identification of natural hybrids (chromosome number, genome composition); (2) the origin and formation mechanism of natural hybrids; (3) the role of natural hybrids in the formation of Triticeae species; (4) to improve the natural hybrid and create new herbage germplasms with good herbage and high fertility.