Genetic diversity in common wheat lines revealed by fluorescence in situ hybridization

Molecular markers and phenotyping have been widely used to evaluate wheat germplasm diversity. However, the feasibility of using chromosome fluorescence in situ hybridization (FISH) to evaluate wheat genetic diversity has not been well investigated. In this study, seventy-six representative Chinese wheat lines in main wheat production area were selected and investigated with multicolour FISH using Oligo-pTa535, Oligo-pSc119.2 and Oligo-(GAA)(8) probes. The results indicated that wheat chromosomes can be clearly recognized by FISH. For wheat A, B and D genomes, the number of FISH types ranged from 2 to 7, 2 to 6 and 1 to 5, respectively. The average number of FISH types in the A and B genomes was higher than that in the genome D. The rye-derived 1RS chromosome in wheat background could also be clearly detected by these probes. The frequency of 1RS in Chinese wheat lines investigated was 48.7%, and most (94.6%) of them belonged to 1BL.1RS. The genetic relationships among the seventy-six Chinese wheat lines subjected to FISH were divided into three clusters, e.g., CL1, CL2 and CL3. Those wheat lines derived from Shandong and Henan Provinces were mainly located in clusters CL1 and CL3, respectively, which may suggest that the FISH type is associated with the adaptation of wheat. These results also indicated that multicolour FISH using a combination of three different oligo-probes generates sufficiently diverse hybridization patterns among wheat lines to evaluate the genetic diversity of wheat.