Genetic Diversity of Recurrent Selection Populations with Ms2 Gene Assessed by Gliadins in Common Wheat ( Triticum aestivum L.)

Abstract

The male-sterile lines with Ms2 gene were highly evaluated in recurrent selection in wheat ( Triticum aestivum L.). Three populations C6 (population after six cycles of selection), C7 (population after seven cycles of selection), and C8 (population after eight cycles of selection) were constructed through recurrent selection with 12 parental materials (P). Acid polyacrymide gel electrophoresis (A-PAGE) analysis was used to identify gliadin patterns and evaluate the genetic diversity in 12 parents and three populations. A total of 63 bands were identified, of which 17 polymorphic bands and 7 unique bands were present in populations and seven polymorphic bands and four unique bands were present in parents. The number of polymorphic and unique bands decreased gradually from C6 to C8, especially for ω- and γ-gliadins. The genetic distances in C6, C7, and C8 were calculated. The distributions of genetic distance were different in three recurrent selection populations. From C6 to C8, the genetic distance was 0.2687, 0.2652 and 0.1987, respectively. Statistically significant differences were detected between C7 and C8 with the T value of 37.9718. The result of cluster analysis based on genetic similarity matrix of three populations fitted well to those of principle coordinates analysis (PCoA). Compared with 12 parents, almost all individuals of three populations are new genotypes. Most of the individuals from C6 and C7 could be divided into two groups, while most individuals of C8 were in one cluster. In conclusion, the results indicated that the genetic diversity was decreased severely according to the information revealed by A-PAGE, although some variations could be created in the recurrent selection. It was necessary to introduce diverse germplasm based on the genetic database of recurrent population to maintain and improve the breeding efficiency in the further program.