Screening of Winter Wheat Accessions from International Variety Trials for Drought Resistance in Southeastern Kazakhstan

Wheat production, globally and in Kazakhstan, is significantly limited by heat stress and drought. The evaluation of agronomic traits related to yield under stress conditions is crucial for identifying yield-limiting factors and selecting drought-tolerant germplasm. The aim of this study was to evaluate the variability of the main agronomic and physiological characteristics of 45 winter wheat collection accessions obtained during CIMMYT international variety trials (23IWWYT-IRR and 22IWWYT-SA) in the arid conditions of Southeastern Kazakhstan (foothills of the Zailiyskiy Alatau, 48° N, 77° E, 740 m above sea level) and to identify drought-resistant germplasm. As a result of three years of research (2019–2022) under drought conditions during the 2020–2021 growing season with a high negative environment index (Ij = −3.07), three adapted genotypes were identified: BONITO-37/MV10-2000, LYMARIVNA, and OK12D22004-016. They had yields of 5.3, 5.6, and 5.2 t/ha, respectively, significantly exceeding the yield of the local commercial variety STEKLOVIDNAYA 24 by 15.4–22.8%. The correlation coefficient between productivity variables was significant and varied from 0.55 ** to 0.82 ***. The percentage decrease in yield under drought conditions was 72.3%, while the drought resistance index was 0.27.