QTL analysis and fine mapping of a QTL for yield-related traits in wheat grown in dry and hot environments

• Published in: Theoretical and applied genetics 2020-01, Vol.133 (1), p.239-257
• Main Authors: Tura, Habtamu, Edwards, James, Gahlaut, Vijay, Garcia, Melissa, Sznajder, Beata, Baumann, Ute, Shahinnia, Fahimeh, Reynolds, Matthew, Langridge, Peter, Balyan, Harindra Singh, Gupta, Pushpendra K., Schnurbusch, Thorsten, Fleury, Delphine
• Format: Article
• Language: English
• Subjects: Agriculture; Alleles; Analysis; Australia; Biochemistry; Biomedical and Life Sciences; Biotechnology; Canada; Chromosome Segregation - genetics; Chromosomes, Plant - genetics; Controlled conditions; Crop yields; Drought; Droughts; Environment; Gene mapping; Genes, Plant; Genetic control; Germany; Haploidy; India; Life Sciences; Mexico; Original; Original Article; Phenology; Phenotype; Physical Chromosome Mapping; Plant Biochemistry; Plant Breeding/Biotechnology; Plant Genetics and Genomics; Quantitative genetics; Quantitative trait loci; Quantitative Trait Loci - genetics; Quantitative Trait, Heritable; Reynolds, Matthew; Seasons; Seeds - growth & development; Triticum - genetics; Triticum - growth & development; Wheat
• ISSN: 0040-5752; 1432-2242
• DOI: 10.1007/s00122-019-03454-6

Genetic control of grain yield and phenology was examined in the Excalibur/Kukri doubled haploid mapping population grown in 32 field experiments across the climatic zones of southern Australia, India and north-western Mexico where the wheat crop experiences drought and heat stress. A total of 128 QTL were identified for four traits: grain yield, thousand grain weight (TGW), days to heading and grain filling duration. These QTL included 24 QTL for yield and 27 for TGW, showing significant interactions with the environment ( Q * E ). We also identified 14 QTL with a significant, small main effects on yield across environments. The study focussed on a region of chromosome 1B where two main effect QTL were found for yield and TGW without the confounding effect of phenology. Excalibur was the source of favourable alleles: QYld.aww - 1B.2 with a peak at 149.5–150.1 cM and QTgw.aww - 1B at 168.5–171.4 cM. We developed near isogenic lines (NIL) for the interval including QYld.aww - 1B.2 and QTgw.aww - 1B and evaluated them under semi-controlled conditions. Significant differences in four pairs of NIL were observed for grain yield but not for TGW, confirming a positive effect of the Excalibur allele for QYld.aww - 1B.2 . The interval containing QYld.aww - 1B.2 was narrowed down to 2.9 cM which corresponded to a 2.2 Mbp genomic region on the chromosome 1B genomic reference sequence of cv. Chinese Spring and contained 39 predicted genes.