Abstract

In 2024, a field study evaluated 30 spring wheat varieties and breeding lines for resistance to common root rot (Bipolaris sorokiniana) across two contrasting agroecological zones in Kazakhstan - the Kazakh Research Institute of Agriculture in Almaty region and Aktobe Agricultural Experimental Station. The experiment compared three treatment conditions: fungicide application, artificial inoculation with B. sorokiniana, and natural infection. Comprehensive assessments included measurements of stem length (77.07-84.24 cm), ear length, spikelet number (up to 14.27 per ear), grain yield (9.67-16.96 g per 50 plants), and 1000-seed weight, along with disease severity evaluation using a 4-point scale. Results demonstrated that genotypes carrying Sb1 and Sb2 resistance genes, particularly line #512 (Sb2) with stable stem length (83.17 cm) and grain yield (14.35 g), and line #575 (Sb1+Sb2) with optimal spikelet number (14.27) and grain weight (9.67 g), showed superior performance under disease pressure. Fungicide treatment proved most effective, yielding plants with maximum stem length (84.24 cm) and grain production (16.96 g). Notable regional variations emerged, with the Aktobe site exhibiting higher tillering capacity (2.32) but shorter stems (77.07 cm), while the Almaty location produced taller plants (81.29 cm) with improved ear structure. These findings underscore the critical interplay between genetic resistance, agronomic practices, and environmental factors in wheat productivity, providing valuable insights for developing region-specific, disease-resistant wheat cultivars in Kazakhstan through integrated breeding approaches that combine genetic improvement with optimized crop management strategies.

Keywords: spring wheat, root rot, disease resistance, agronomic traits, fungicides, breeding, yield.