Quantitative trait loci of stripe rust resistance in wheat

Abstract

Key messageOver 140 QTLs for resistance to stripe rust in wheat have been published and through mapping flanking markers on consensus maps, 49 chromosomal regions are identified.AbstractOver thirty publications during the last 10 years have identified more than 140 QTLs for stripe rust resistance in wheat. It is likely that many of these QTLs are identical genes that have been spread through plant breeding into diverse backgrounds through phenotypic selection under stripe rust epidemics. Allelism testing can be used to differentiate genes in similar locations but in different genetic backgrounds; however, this is problematic for QTL studies where multiple loci segregate from any one parent. This review utilizes consensus maps to illustrate important genomic regions that have had effects against stripe rust in wheat, and although this methodology cannot distinguish alleles from closely linked genes, it does highlight the extent of genetic diversity for this trait and identifies the most valuable loci and the parents possessing them for utilization in breeding programs. With the advent of cheaper, high throughput genotyping technologies, it is envisioned that there will be many more publications in the near future describing ever more QTLs. This review sets the scene for the coming influx of data and will quickly enable researchers to identify new loci in their given populations.

Novel QTL for Stripe Rust Resistance on Chromosomes 4A and 6B in Soft White Winter Wheat Cultivars

“…In 2012, a new race, PSTv-52 was identified and has since become the most abundant race in the PNW, but Eltan is only considered to be moderately susceptible-susceptible to this race [49]. Most reported APR genes are stable across environments, years, and races [31,37,50]. Greenhouse studies are being conducted with different races to differentiate the effect of race structure on this APR QTL.…”

“…Few stripe rust resistance genes have been cloned with perfect molecular markers [51]. Previously, single SSR markers, or flanking markers, were sufficient to determine presence or absence of a linked locus [31]. Now, with the use of SNP markers for genotyping and linkage map development, single SNP markers linked to QTL are likely not effective to fully distinguish presence or absence of a linked QTL.…”

“…Unfortunately, seed of additional varieties with QTL reported to be located on chromosome 6B was not available. However, it was apparent that overlapping QTL were present on this chromosome [31].…”

“…Chromosome 4A SSR markers were available only for QTL in Stephens, Avocet S, and IDO444. Vazquez et al [43] identified multiple APR QTL in Stephens with one identified on 4A by linkage to SSR marker Xbarc70; Eltan did not share that allele [31]. The 4A QTL from IDO444, described by Chen et al [42], was found at a similar location to a QTL in Kariega [41].…”

Molecular mapping of a recessive stripe rust resistance gene yrMY37 in Chinese wheat cultivar Mianmai 37

“…In general, two types of resistance, namely, seedling resistance and adult-plant resistance (APR), are present in wheat (Chen 2005;He et al 2011;Rosewarne et al 2013). Seedling resistance can be detected at seedling stage and remains effective throughout the entire growth.…”