MetaQTL analysis for powdery mildew resistance in barley (Hordeum vulgare L.)

Powdery mildew is a highly destructive and common disease in barley (Hordeum vulgare L). Therefore, developing stable resistance against it poses a significant challenge for plant breeders. Identifying gene locations that control specific resistance to powdery mildew is a top priority for barley breeders. In the current study, 111 QTL controlling powdery mildew disease were collected from previous research and their information was analysed. RIL, DH, and BC populations were used to prepare a genetic map. Finally, a consensus genetic map was created based on SSR, AFLP, CAPS, EST, DArT, SAP, RAPD, RFLP, IFLP, RGA, STS, and SNP markers using concatenation profiles. The total length of the consensus map was 2124.43 cm. Through Meta-QTL (MQTL) analysis 47 QTLs were successfully projected onto the consensus genetic map leading to the identification of 23 stable MQTL (MQTLs) and 311 candidate genes associated with powdery mildew resistance. Among these MQTL2.1 MQTL5.2 and MQTL5.4 exhibited the highest resistance effects with R² values ranging from 23% to 28%. The identified candidate genes and MQTLs provide valuable genomic resources for marker-assisted selection (MAS) and genomic selection (GS) programs. For practical breeding applications we recommend utilizing the markers MWG2033 Bmag0218 ABC321 MWG2135 AWBMS70 and Scssr10148 to accelerate the development of powdery mildew-resistant barley cultivars