Genomic regions on chromosome 5H containing a novel QTL conferring barley yellow dwarf virus-PAV (BYDV-PAV) tolerance in barley

Hongliang Hu,Sergey Shabala,Sanjiv Gupta,Shormin Choudhury,Meixue Zhou

doi:10.1038/s41598-019-47820-2

Abstract

Barley yellow dwarf virus is a widespread disease affecting plant growth and yield in cereal crops including barley. Complete resistance to BYDV encoded by a single gene is lacking in barley. To identify novel resistance genes that can be further utilised in breeding for plant disease resistance, a doubled haploid population originated from a cultivated barley with a known resistance gene and a wild barley was constructed and assessed for barley yellow dwarf tolerance in three trials with two in Tasmania (TAS) and one in Western Australia (WA). We identified two Quantitative trait loci (QTL) in both Tasmanian trials, and four QTL in Western Australian trial. Two QTL from TAS trials were also detected from WA. The QTL on chromosome 3H corresponds to the known major resistance gene Ryd2. The other QTL, Qbyd-5H, represents a potential new resistance locus and contributed 7.0~10.4% of total phenotypic variation in the three trials. It was mapped within the interval of 125.76~139.24 cM of chromosome 5H. Two additional minor effect QTL were identified on chromosome 7H from WA trial, contributing slightly less effect on BYD tolerance. The consistently detected new gene on chromosome 5H will potentially serve as a novel source of tolerance to achieve more sustainable resistance to BYDV in barley.

Highlights

Source of variation Genotype Environment Genotype × Environment Error dfa Sum of squares Mean square F value Pr > F
Several quantitative trait loci (QTL) conferring tolerance to different yellow dwarf virus species have been identified. del Blanco et al.[30] identified two major QTL for CYDV-RPV tolerance on chromosomes 2H (Qcyd.MaBu-1) and 7H (Qcyd.MaBu-2), and 4 minor QTL on chromosomes 3H, 4H, and 2H were identified from a population of recombinant inbred lines constructed with Madre Selva and Butta 12
Both genotype and environment showed significant effects on symptom scores for the doubled haploid (DH) lines (Table 1), with the effect of genotype being more significant than environment

Summary

Introduction

Source of variation Genotype Environment Genotype × Environment Error dfa Sum of squares Mean square F value Pr > F. The second resistance gene, Ryd[2] was identified in Ethiopian landraces[18] It has been introgressed into high-yielding barley cultivars, delivering much higher level of tolerance[19,20]. The mechanism of resistance of Ryd[2] may partly be attributed to its ability to reduce virus titre in BYDV-PAV or –MAV infected young plants[22] This effect was not observed in old plants[23,24]. With the aim of identifying novel genes responsible for BYDV-PAV tolerance/resistance, we, report quantitative trait loci (QTL) with tolerance trait of leaf yellowing using a doubled haploid (DH) population of barley

Methods

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Discussion

Conclusion