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

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 (He=0.225 4, I=0.355 7) and gene flow between populations was relatively low (Nm=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.

Keywords

• aegilops tauschii
• genetic diversity
• clustering analysis
• population structure
• issr analysis