Evaluation of morpho-biological indicators of the winter wheat RIL population resistant to yellow rust

Yellow rust (Puccinia striiformis f. sp. tritici) is a critical threat to wheat production in Uzbekistan, often resulting in significant yield losses. Developing resilient varieties through recombinant inbred line (RIL) populations is essential to stabilise regional food security. This study evaluated the morpho-biological and agronomic performance of an F8 RIL population (n = 100) derived from a cross between the resistant donor KR12-9010 and the high-yielding recurrent parent Jaykhun. The experiment was conducted during 2024–2025 at the Centre of Genomics and Bioinformatics, Tashkent (41°20' N, 69°18' E), using a randomised complete block design (RCBD) with three replicates. Plants were grown under an artificial infectious background created using a 1:300 ratio of P. striiformis urediniospores powder. Key observations included tillering, plant height, spike length, grain count per spike and grain weight per spike. Statistical analyses, including K-means clustering and analysis of variance (ANOVA), identified 43 “RIL_max” lines that were significantly superior to the recurrent parent Jaykhun. Notably, 26 elite lines surpassed the recipient in all evaluated traits and matched or exceeded the donor line KR12-9010, even under high disease pressure. These lines demonstrated successful introgression of resistance along with improved yield components. These findings provide advanced germplasm for wheat breeding programmes, offering a practical solution for sustainable production in rust-affected areas.