Meta-QTL Analysis for Stripe Rust Resistance in Wheat

Abstract Stripe rust caused by Puccinia striiformis f. sp. tritici Eriks. & E. Henn (Pst) is one of the most prevalent wheat diseases causing upto 70% yield losses worldwide. The present study was conducted in wheat for the first time to identify important meta-QTL (MQTL) regions for their use in developing stripe rust resistant wheat cultivars and to understand the genetic architecture of stripe rust resistance in wheat. For this purpose, a dense consensus map consisting of 76,753 markers was constructed and 353 QTLs from earlier studies were projected on this consensus map. As many as 61 MQTLs were identified using 184 (out of 353) original QTLs. Ten important genomic regions including six breeders’ MQTLs (PVE >20%) and four MQTL hotspots were selected to be used by wheat breeders. As many as 409 important candidate genes (CGs) were also identified, which either encoded known R proteins (265) or showed differential expression (144) due to stripe rust infection. These included genes encoding the following proteins: NBS-LRR, WRKY domains, ankyrin repeat domains, sugar transporters, etc. Overall, the present study provided robust MQTLs and underlying CGs which may be potential targets for molecular breeding for development of stripe rust resistant wheat cultivars or may be the target for future molecular studies to understand the mechanism of stripe rust resistance.