粗山羊草种质遗传多样性及群体结构的ISSR分析

Genetic diversity and population structure of Aegilops tauschii accessions based on ISSR method

关键词:  粗山羊草, 遗传多样性, 聚类分析, 群体结构, ISSR分析

Key words:  Aegilops tauschii, genetic diversity, clustering analysis, population structure, ISSR analysis

摘要:

粗山羊草分布范围广,遗传变异丰富,被认为是改良普通小麦的重要基因源。为深入了解不同来源粗山羊草种质的遗传多样性和群体结构,该研究利用ISSR分子标记对56份粗山羊草种质进行了遗传多样性和群体结构分析。结果表明:(1)16个ISSR引物共检测170条多态性位点,每个ISSR引物多态性位点为3～18条,平均为10.63条; 多态性信息(PIC)变异范围为0.17～0.85,平均为0.67。(2)粗山羊草4个群体的遗传多样性比较显示,中亚粗山羊草的群体遗传多样性水平最高(H_e=0.225 4,I=0.355 7),群体间的基因流较低(N_m=1.638 6)。(3)聚类结果在遗传相似系数约0.67处,来源于塔吉克斯坦6份和土库曼斯坦2份粗山羊草种质材料聚成一类(Group 2); 其他48份种质材料形成一大类(Group 1),其中Group 1可进一步分成3个Sub亚类,呈现出来源相同的粗山羊草种质材料倾向聚在一起。(4)群体结构分析将56份粗山羊草种质分为5个群体,其中,来源于西亚伊朗V群体种质材料遗传背景比较一致,混杂程度相对较低; 进一步分析各群体Q值,发现IV群体种质材料亲缘关系的来源相对复杂,遗传多样最为丰富。该研究结果可为粗山羊草种质亲缘关系解析、种质多样性保护提供重要参考依据,为其科学利用以及进化研究奠定基础。

Abstract:

Aegilops tauschii is considered as an important gene source for improving common wheat, which has wide distribution and rich genetic variation. In order to understand genetic diverstity and population structure of A. tauschii from different origins, ISSR markers were used to evaluate genetic diversity and population structure of 56 A. tauschii accessions. The results were as follows:(1)The 170 polymorphic bands were detected by 16 ISSR primers, and polymorphic bands of each ISSR primer ranged from 3 to 18, with an average of 10.63. The variation of polymorphism information content(PIC)ranged from 0.17 to 0.85, with an averaged of 0.67.(2)The comparison among four populations indicated that the population genetic diversity of Central Asia was the highest(H_e=0.225 4, I=0.355 7)and gene flow between populations was relatively low(N_m=1.638 6).(3)The clustering results showed that 56 A. tauschii accessions were divided into two groups at the genetic similarity coefficient 0.67, of which eight accessions from Tajikistan and Turkmenistan were clustered in Group 2. And, the Group 1 including 48 accessions could be further divided into three sub-groups, which indicated that A. tauschii accessions with clustering together have the same origin.(4)Based on population structure analysis, 56 A. tauschii accessions were divided into five populations, of which the V population from Iran in West Asia had relatively consistent genetic background and relatively low degree of hybridization. Furthermore, the Q value analysis of populations showed that the genetic relationship of IV population were relatively complex, producing the most abundant genetic diversity. The results of this study can provide an important reference for analysis of genetic relationship, protection of biodiversity, and lay a foundation for the scientific utilization and evolution research of A. tauschii.