The presented study aims to select the early-maturing and high-yielding winter wheat genotypes via the assessment of various eco-geographical groups and to illustrate their scientific significance for the diverse environmental conditions of the Kashkadarya Region of the Republic of Uzbekistan. Twenty-four advanced wheat lines underwent selection and evaluation for comparison with six regional and promising cultivars to further improve and use for crossbreeding. Overall, eight cultivars showed promising in the desert zone of the Kashkadarya Region, 24 in the middle area, and 13 in the region’s foothills, while selecting five for the desert zone, six in the middle, and 10 in the foothills of Uzbekistan. Seventeen cultivars and advanced lines attained selection for the desert area of District Kasbi with higher protein content (14%), 21 in the middle zone of District Karshi, and 22 in the foothills of District Shahrizabz. Cultivars and advanced lines selected for the desert area of District Kasbi, in the middle zone of District Karshi, and in the foothills of District Shahrizabz numbered 14, 14, and three, respectively, where the gluten content was more than 30%. Weather conditions also affect the wheat genotype yields in the irrigated areas, and due to less rainfall in March-May of 2011, in the desert and foothills, the average yield declined by 0.2–0.23 and 0.15–0.25 t/ha in the deserts and foothills, respectively, compared with other years. The precipitation in March-May strongly correlated (r = 0.47) with the grain yield in winter bread wheat.

Keywords: winter bread wheat (Triticum aestivum L.), soil, climate, weather condition, cultivars, advanced lines, precipitation, grain yield and quality

Key findings: The present-day study selected early-maturing, highly productive, and good-quality cultivars and advanced lines of winter bread wheat for diverse soil and weather conditions of the Kashkadarya Region, Uzbekistan. Assessing the developmental phases of winter bread wheat in the foothills, middle, and desert regions of Kashkadarya resulted in selecting and identifying early-maturing and high-yielding wheat genotypes suitable for each zone.