*Corresponding author: Youngjun Mo (yjmo@jbnu.edu)

Wheat, a staple crop globally, ranks as the second most consumed food crop in Korea following rice. However, the self-sufficiency rate of wheat is low (1.1%, as of 2021) in Korea, leading to a high dependency on imports. Therefore, developing improved wheat varieties for Korean environments is vital to improve food security. As wheat breeding in Korea has focused on developing early-maturing varieties suitable for the rice-wheat double cropping system, genetic diversity is highly limited.

Hence, it is crucial to establish a genetically diverse germplasm pool to discover and utilize valuable breeding materials for the development of competitive varieties. This study aimed to assess the genetic diversity among 359 underutilized wheat accessions collected from 44 countries based on 13 major agronomic traits evaluated under field conditions and select accessions suitable as foundational materials for developing a breeding population. The agricultural traits of 359 accessions were compared with those of Geumgang, one of the major wheat varieties cultivated in Korea.

Among the agricultural traits investigated, days to heading from sowing (DTH) averaged 195 days (range 168–217 days, Geumgang 171 days). Spikelet number per spike (SNS) and thousand grain weight (TGW) averaged 20.8 (range 12.8–30.2, Geumgang 14.4) and 37.3 g (range 21.8–64.6 g, Geumgang 45.3 g), respectively.

Using k-means cluster analysis, the 359 resources were classified into three groups, and characteristics among these groups were compared to understand the genetic diversity within the population. Based on the results, promising accessions with high SNS and TGW with suitable maturity under Korean environment were selected.

The average SNS of the selected accessions was 24.3, 69% higher than that of Geumgang, while the average TGW of the selected accessions was 55.1 g, 22% higher than that of Geumgang.

**Acknowledgment: This research was supported by Rural Development Administration (RS-2024-00432490), Republic of Korea.