Winter Wheat Genetic Resources for Breeding Common Bunt Resistance in Organic Farming Systems

Common bunt (CB), caused by Tilletia caries and Tilletia laevis, poses a significant threat to wheat grain quality and yield. In organic farming, the development of resistant genotypes is the most effective way to combat the pathogen. This study aimed to identify new resistance sources against CB in international nurseries: Winter Wheat Nursery from Central Asia (WWN-CA) and International Common Bunt Resistance Nursery (CBUNT-RN), for strengthening winter breeding programs in Kazakhstan. Germplasm panels were evaluated against CB under artificial infection conditions in southeastern Kazakhstan and genotyped with KASP markers associated with QTLs (QBt.ifa-1AL, QBt.ifa-1BS, QBt.ifa-7AL and QBt.ifa-7DS) conferring bunt resistance. Results of immunological experiments and genotyping revealed 7 and 11 genotypes in WWN-CA and CBUNT-RN, respectively, and resistance to CB. CB incidence negatively correlated with SL (r = −0.23), NSS (r = −0.31), NKS (r = −0.41), and GWS (r = −0.44) (all p ≤ 0.01), in WWN-CA. ANOVA confirmed these findings, in which a pronounced reduction in these yield components was observed between inoculated and control HS groups (p ≤ 0.05). The QTL QBt.ifa-1AL on chromosome 1A shows promise for MAS against CB. The novel genetic knowledge and resistant resources identified here represent a valuable tool to enrich Central Asian germplasm with new alleles of resistance genes to advance organic farming in Kazakhstan.