中文摘要：

为揭示鸭茅栽培品种与野生材料间遗传多样性的差异，本研究利用２５对ＳＳＲ引物对２３份鸭茅材料（包括品种、四倍体、二倍体等）进行扩增，获得了２５１条清晰条带，平均每对引物扩增１０．０４个条带，多态性比率为１００％，多态性信息含量（ＰＩＣ）的变化范围为０．２４（Ａ０１Ｅ１４）～０．４２（Ａ０１Ｆ２４，Ａ０３Ｂ１６），平均值为０．３３。２３份材料的遗传距离变化范围为０．１０６５～０．６０６１，平均遗传距离为０．３８７０，６个栽培品种的平均遗传距离为０．３０８８，低于所有材料遗传距离的平均水平。聚类分析将相似地理来源、相同倍性和品种分别聚类，主成分分析与聚类分析结果一致。ＡＭＯＶＡ 分析结果表明，类群内的遗传变异大于类群间的遗传变异；不同类群的遗传多样性比较表明，野生材料类群与栽培品种类群遗传多样性差异不明显，而四倍体类群较二倍体类群具有更丰富的遗传多样性。

英文摘要：

To reveal the genetic diversity in cultivated and wild orchardgrass, 25 SSR primer pairs were used to amplify 23 accessions （including cultivar, tetraploid, diploid etc. ）. The average number of bands per primer pair was 10.04 and 251 clear bands were obtained of which 100 percent were polymorphic. The average genetic diversity, as measured by the polymorphism information content （PIC） was 0. 33, and ranged from 0. 24 （A01E14） to 0.42 （A01F24, A03B16）. The genetic distance of 23 accessions varied from 0. 106 5 to 0. 606 1, with an average of 0. 387 0. The mean genetic distanee among 6 cultivars was 0. 308 8, lower than the average of all accessions. Clustering analysis showed that 23 accessions could be divided into different groups according to the geographic distributions, ploidy, and eultivar. Principal component analysis was consistent with clustering analysis. The analysis of molecular variance indicated that the genetic variation was higher within groups than between groups. The result of comparison of genetic diversity among different groups showed that there was no significant difference between the group of wild and cultivated orchardgrass, but the genetic diversity of the tetraploid group was much richer than that of the diploid group.