Molecular Mapping of Stripe Rust Resistance Gene Yr81 in a Common Wheat Landrace Aus27430

Abstract

The deployment of diverse sources of resistance in new cultivars underpins durable control of rust diseases. Aus27430 exhibited a moderate level of stripe rust resistance against Puccinia striiformis f. sp. tritici (Pst) pathotypes currently prevalent in Australia. Aus27430 was crossed with the susceptible parent Avocet S (AvS) and subsequent filial generations were raised. Monogenic segregation observed among Aus27430/AvS F3 families was confirmed through stripe rust screening of an F6 recombinant inbred line (RIL) population, and the resistance locus was temporarily named YrAW5. Selective genotyping using an Illumina iSelect 90K wheat SNP bead chip array located YrAW5 in chromosome 6A. Genetic mapping of the RIL population with linked 90K SNPs that were converted into PCR-based marker assays, as well as SSR markers previously mapped to chromosome 6A, confirmed the chromosomal assignment for YrAW5. Comparative analysis of other stripe rust resistance genes located in chromosome 6A led to the formal designation of YrAW5 as Yr81. Tests with a marker linked with Yr18 also demonstrated the presence of this gene in Aus27430. Yr18 interacted with Yr81 to produce stripe rust responses lower than those produced by RILs carrying these genes individually. Although gwm459 showed higher recombination with Yr81 compared with the other flanking marker KASP_3077, it amplified the AvS allele in 80 cultivars, whereas KASP_3077 amplified AvS allele in 67 cultivars. Both markers can be used in marker-assisted selection after confirming parental polymorphism.

An ancestral NB-LRR with duplicated 3′UTRs confers stripe rust resistance in wheat and barley

“…Over 80 wheat stripe rust resistance ( R ) genes ( Yr1–Yr81 ) have been permanently named 11 . Of the seven genes cloned so far, Yr5 , Yr7 and YrSP , a gene cluster, encodes nucleotide-binding (NB) and leucine-rich repeat (LRR) proteins 12 ; Yr15 has two kinase-like domains 13 ; Yr36 has a kinase domain and a lipid binding domain 14 ; Lr34/Yr18 encodes a putative ABC transporter 15 ; and Lr67/Yr46 encodes a predicted hexose transporter 16 .…”

Identification of a recessive gene YrZ15-1370 conferring adult plant resistance to stripe rust in wheat-Triticum boeoticum introgression line

“…To date, three stripe rust resistance genes (Yr38, Yr42, and Yr81) have been assigned on chromosome 6A. Yr81 located in the short arm of chromosome 6A, was detected in an Australian common wheat landrace Aus27430 (Gessese et al 2019). Yr38 (Marais et al 2006) and Yr42 (Marais et al 2009) are present in translocated segments from wild relatives Aegilops sharonensis (2n = 14, S sh S sh ) and Ae.…”

“…To date, more than 80 stripe rust resistance genes (Yr1-Yr83) have been permanently named (Gessese et al 2019;Pakeerathan et al 2019;).…”

“…In contrast, APR generally provides a partial level of resistance that is non-race speci c and, in some cases, has proven to be more durable than ASR (Ellis et al 2014;Fu et al 2009;Lagudah et al 2009). To date, more than 80 stripe rust resistance genes (Yr1-Yr83) have been permanently named (Gessese et al 2019;Pakeerathan et al 2019;.…”

Mapping Quantitative Trait Loci for High-Temperature Adult-Plant Resistance to Stripe Rust in Spring Wheat PI 197734 Using a Doubled Haploid Population and Genotyping by Multiplexed Sequencing

“…Individual genes or QTL for APR or HTAP resistance generally provide only partial protection, but commercially acceptable levels of resistance can be achieved by pyramiding multiple genes or QTL, which has been recommended for crop resistance breeding programs (Chen, 2013;Nelson et al, 2018). Although more than 80 formally designated Yr (for yellow rust) genes and hundreds of QTL have been identified for resistance to stripe rust of wheat (Maccaferri et al, 2015;Wang and Chen, 2017;Feng et al, 2018;Nsabiyera et al, 2018;Gessese et al, 2019;Pakeerathan et al, 2019;, many of them have already lost their effectiveness. Characterization of new resistance resources is important to achieve genetic diversity for resistance among new wheat cultivars.…”