Genetic Diversity Assessment of the International Maize and Wheat Improvement Center and Chinese Wheat Core Germplasms by Non-Denaturing Fluorescence In Situ Hybridization

Germplasm is the material basis for crop genetic improvement and related basic research. Knowledge of genetic diversity present in wheat is the prerequisite for wheat breeding and improvement. Non-denaturing fluorescence in situ hybridization (ND-FISH) is a powerful tool to distinguish chromosomal polymorphisms and evaluate genetic diversity in wheat. In this study, ND-FISH using Oligo-pSc119.2-1, Oligo-pTa535-1, and Oligo-(GAA)(7) as probes were used to analyze the genetic diversity among 60 International Maize and Wheat Improvement Center (CIMMYT) derived wheat lines, and 93 cultivated wheat and landraces from the Chinese wheat core germplasm. A total of 137 polymorphic FISH patterns were obtained, in which 41, 65, and 31 were from A-, B-, and D-genome chromosomes, respectively, indicating polymorphism of B-genome > A-genome > D-genome. In addition, 22 and 51 specific FISH types were observed in the two germplasm resource lines. Twelve types of rearrangements, including seven new translocations, were detected in all 153 wheat lines. Genetic relationships among 153 wheat lines were clustered into six groups. Our research provides cytological information for rational utilization of wheat germplasm resources.