Genetic diversity of Asian and European common wheat lines assessed by fluorescence in situ hybridization

Understanding the genetic diversity of wheat is important for wheat breeding and improvement. However, there have been limited attempts to evaluate wheat diversity using fluorescence in situ hybridization (FISH). In this study, the chromosomal structures of 149 wheat accessions from 13 countries located between the latitudes of 30° and 45°N, the principal growing region for wheat, were characterized using FISH with pTa535 and pSc119.2 probes. The ranges of the numbers of FISH types in the A-, B-, and D-genomes were 2-8, 3-7, and 2-4, respectively, and the average numbers in the A- and B-genomes were greater than in the D-genome. Chromosomal translocations were detected by these probes, and previously undescribed translocations were also observed. Using the FISH, the genetic relationships among the 149 common wheat lines were divided into three groups (G1, G2, and G3). G1 mainly consisted of Southern European lines, G2 consisted of most lines from Japan and some lines from Western Asia, China, and Korea, and G3 consisted of the other lines from Southern Europe and most of the lines from Western Asia, China, and Korea. FISH karyotypes of wheat chromosomes distinguished chromosomal structural variations, revealed the genetic diversity among wheat varieties. Furthermore, these results provide valuable information for the further genetic improvement of wheat in China.