QTL mapping for seedling and adult plant resistance to stripe and leaf rust in two winter wheat populations

Abstract

The two recombinant inbred line (RIL) populations developed by crossing Almaly × Avocet S (206 RILs) and Almaly × Anza (162 RILs) were used to detect the novel genomic regions associated with adult plant resistance (APR) and seedling or all-stage resistance (ASR) to yellow rust (YR) and leaf rust (LR). The quantitative trait loci (QTLs) were detected through multi-year phenotypic evaluations (2018–2020) and using high-throughput DArTseq genotyping technology. RILs exhibited significant genetic variation with p < 0.001, and the coefficient of variation ranged from 9.79% to 47.99% for both LR and YR in all Environments and stages of evaluations. The heritability is quite high and ranged between 0.47 and 0.98. We identified nine stable QTLs for YR APR on chromosomes 1B, 2A, 2B, 3D, and 4D and four stable QTLs for LR APR on chromosomes 2B, 3B, 4A, and 5A. Furthermore, in silico analysis revealed that the key putative candidate genes such as cytochrome P450, protein kinase-like domain superfamily, zinc-binding ribosomal protein, SANT/Myb domain, WRKY transcription factor, nucleotide sugar transporter, and NAC domain superfamily were in the QTL regions and probably involved in the regulation of host response toward pathogen infection. The stable QTLs identified in this study are useful for developing rust-resistant varieties through marker-assisted selection (MAS).

Integrated genome-wide association and transcriptomic analysis to identify receptor kinase genes to stripe rust resistance in wheat germplasm from southwestern China

“…The candidate gene TraesCS4B02G320600 (located at 612,024,567 bp on chromosome 4B) overlapped with the positions of QYr.sun-4B , QYrsk.wgp-4BL , YrZH22 , and QYr.crc-4BL [ 40 – 43 ] , in which QYr.sun-4B and QYr.crc-4BL were micro efficiency loci inherited from synthetic hexaploid CPI133872 and cultivar Toropi, respectively, and QYrsk.wgp-4BL and Yr62 might be different alleles on the same locus. The candidate gene TraesCS6B02G415100 (located at 687,954,847 bp on chromosome 6B) overlapped with the position of QYR-ASR-Pst3-6B.3 [ 44 ], which was identified as the ASR gene locus. The other 11 candidate genes do not overlap with QTL loci reported in previous studies and may be new disease resistance genes.…”