Diversity Analysis Using Agricultural Traits and SSR Markers of Wheat Germplasms

Abstract

Breeders typically use core collections of a specific trait or core collections selected by a few genotypes to efficiently select breeding materials or to study functional genes. As a result, many accessions have been deemed redundant or duplicated and are no longer considered for use. This study aimed to investigate the agronomical characteristics and genetic diversity of 1,514 previously unused and unstudied wheat germplasms and to confirm their value as breeding materials using population structure analysis. The performance of these wheat germplasms was compared with that of 8,878 wheat breeding materials and 72 known Korean wheat cultivars. The results of agronomic trait diversity comparison showed that the germplasm populations used for breeding research did not completely encompass the unused germplasm populations. The agronomic traits of wheat germplasms varied greatly. ANOVA and PCA results revealed the greatest differences in growth habits (CV=0.339), panicle length (CV=0.330), and awn length (CV=0.296). To accurately assess the value of unused wheat germplasms as breeding materials, 106 SSR markers were extracted from the analysis of four representative Korean cultivars: Geuru, Geumgang, Uri, and Jokyoung. Among these, 24 SSR markers were chosen, and 129 wheat resources were subjected to population structure analysis, which revealed five subpopulations. Most of the 34 germplasms that originated in Korea were distributed in subpopulation 1 (18 accessions, 52.9%) and subpopulation 4 (12 accessions, 35.3%). Subgroups 2, 3, and 5 differed significantly in agronomic traits and genotypes, indicating their potential as breeding materials. The findings of this study could serve as a foundation for breeders and aid in the discovery and utilization of new wheat breeding materials.