Identification and Characterisation of Stripe Rust Resistance Genes <i>Yr66</i> and <i>Yr67</i> in Wheat Cultivar VL Gehun 892

oleh: Harbans Bariana, Lakshmi Kant, Naeela Qureshi, Kerrie Forrest, Hanif Miah, Urmil Bansal

Format: Article
Diterbitkan: MDPI AG 2022-01-01

Deskripsi

Wheat cultivar VL Gehun 892 has shown a high level of resistance against Australian <i>Puccinia striiformis</i> f. sp. <i>tritici</i> (Pst) pathotypes. In this study, it was crossed with Westonia, a susceptible wheat cultivar, and digenic segregation was observed in the derived population against Pst pathotype 134 E16A+Yr17+Yr27+. Single-gene recombinant inbred line (RIL) populations were developed from F<sub>3</sub> families (VL Gehun 892/Westonia#1 and VLGehun 892/Westonia#4) that showed monogenic segregations with two distinct phenotypes. Single-gene segregation against Pst pathotype 134 E16A+Yr17+Yr27+ was confirmed in both F6 RIL populations. Bulked segregant analysis using a 90K Infinium SNP array placed <i>YrVL1</i> in the short arm of chromosome 3D and <i>YrVL2</i> in the long arm of chromosome 7B. Kompetitive allele specific polymerase chain reaction (KASP) assays were developed for the SNPs linked with <i>YrVL1</i> and <i>YrVL2</i> and were mapped onto the respective populations. <i>KASP_48179</i> (0.6 cM proximal) and <i>KASP_18087</i> (2.1 cM distal) flanked <i>YrVL1</i>, whereas <i>YrVL2</i> was mapped between <i>KASP_37096</i> (1.2 cM proximal) and <i>KASP_2239</i> (3.6 cM distal). Based on their pathotypic specificities, map locations, and stages of expression, <i>YrVL1</i> and <i>YrVL2</i> were demonstrated to be unique loci and named <i>Yr66</i> and <i>Yr67</i>, respectively. Markers linked with these genes showed more than 85% polymorphism when tested on a set of 89 Australian cultivars and hence could be used for the marker-assisted selection of these genes in wheat breeding programs, following checks of parental polymorphisms.