Phenotypic characterization of underutilized common wheat germplasm for diversifying breeding materials in Korea

Wheat, one of the most important cereal crops globally, stands as the second most consumed crop in Korea following rice. However, the self-sufficiency rate of wheat is extremely low (1.1%, as of 2021) in Korea, leading to an excessive dependency on imports. Therefore, developing wheat varieties with high productivity and quality for Korean environments is crucial to improve self-sufficiency. As wheat breeding in Korea has mainly focused on developing early-maturing varieties suitable for the rice-wheat double cropping system, genetic diversity is highly limited. Hence, it is essential to establish a genetically diverse germplasm pool to discover and utilize valuable breeding materials for the development of competitive varieties. This study has two main objectives: (i) Assess genetic diversity among 359 underutilized wheat accessions from 45 countries based on a comparative analysis of nine key agronomic traits. (ii) Select superior accessions which can be utilized for building a breeding population. The agronomic traits of the 359 wheat accessions exhibited wide variation. Using principal component and k-means cluster analyses, the 359 accessions were classified into three groups, and characteristics among these groups were compared to analyze genetic diversity within the population. Based on the results, accessions with superior spikelet number per spike (SNS) and thousand grain weight (TGW) were selected for further use in breeding and genetic analysis.