Identification of new QTL for yield-related traits in Chinese landrace and elite wheat varieties through a genome-wide linkage mapping

Spike length (SL), fertile spikelet number per spike (SNS), thousand grain weight (TGW) and plant height (PH) are important agronomic traits related to yield in wheat. By the 55 K SNP assay, we constructed a high-density genetic linkage map with 186 F6 recombinant inbred lines developed between Chinese landrace wheat Banmangzi and an elite variety Jimai 22. Eighteen QTLs for SL, SNS, TGW and PH were detected. A new stable major QTL for SL was located on chromosome 2DS, with physical position 19.6 Mb and explaining 20.1–27.9% of the phenotypic variances in three environments, with the favorable allele from Banmangzi. And the QTL was co-located with QSNS.saas-2D.1 and QPH.saas-2D.2 which were detected in two environments and explained up to 18.5% of phenotypic variances for SNS. In addition, an major QTL for TGW was detected on chromosome 6AS, explaining 14.6–22.3% of the phenotypic variances in three environments. Four candidate genes for yield-related traits were identified, encoding IAA-amino acid hydrolase ILR1 and growth-regulating factor for SL, flowering promoting factor-like 1 and sucrose-phosphate synthase for TGW, respectively.