基于表型性状的羊草遗传多样性评价

Evaluation of Genetic Diversity of Leymus chinensis Based on Phenotypic Traits

羊草(Leymus chinensis)是禾本科赖草属多年生根茎型牧草,是我国北方草原优良牧草之一。较高的遗传多样性是羊草多重抗逆性的遗传基础。全球气候变化和生境破碎化导致草原加剧退化,严重威胁羊草遗传多样性。为评价羊草遗传多样性,本文以66份不同地理来源羊草为试验材料,在同质园栽培条件下,基于17个性状,计算Shannon-Wiener多样性指数,分析羊草遗传多样性地理分布。结果表明:羊草不同性状的遗传多样性差异较大,数量性状的遗传多样性高于质量性状;5个质量性状的遗传多样性指数平均为0.861,其中锈病发生程度遗传多样性最高;17个数量性状的多样性指数平均值为1.257,其中叶长宽比遗传多样性最高;内蒙古中部地区是羊草遗传多样性分布中心,也是遗传多样性保护重点区域。

Leymus chinensis,a perennial rhizomatic grass,belonging to the family Gramineae,genus Leymus is an excellent wild forage grass in northern China rangeland.High genetic diversity is the genetic basis of multiple stress resistance characteristics of L.chinensis.Grassland degradation due to global climate change and habitat fragmentation,poses a serious threat to the genetic diversity of L.chinensis germplasm.In order to evaluate the genetic diversity of L.chinensis,66 accessions of L.chinensis from different geographical origins were cultivated in a common garden,and Shannon-Wiener diversity index was calculated based on 17 traits to analyze the geographical distribution of genetic diversity of L.chinensis.The main conclusions were as follows:There were significant differences in the genetic diversity of different traits.Overall,the genetic diversity of quantitative traits was higher than that of qualitative traits.The genetic diversity index of 5 qualitative traits averaged 0.861,among which the genetic diversity of the occurrence degree of rust was the highest.The diversity index of 17 quantitative traits averaged 1.257,among which the genetic diversity of LL/LW was the highest.Central Inner Mongolia was the distribution center of genetic diversity and the key area for genetic diversity protection of L.chinensis.