Mining the Vavilov wheat diversity panel for new sources of adult plant resistance to stripe rust

Dilani T Jambuthenne,Lee T Hickey,Naveenkumar Athiyannan,Sambasivam K Periyannan,Eric Dinglasan,Elizabeth Aitken,Adnan Riaz,Greg Platz,Laura Ziems,Kai P Voss-Fels,Ian Godwin,Samir Alahmad,Olga Afanasenko,Wei Ling Ng

doi:10.1007/s00122-022-04037-8

Abstract

Key messageMulti-year evaluation of the Vavilov wheat diversity panel identified new sources of adult plant resistance to stripe rust. Genome-wide association studies revealed the key genomic regions influencing resistance, including seven novel loci.Wheat stripe rust (YR) caused by Puccinia striiformis f. sp. tritici (Pst) poses a significant threat to global food security. Resistance genes commonly found in many wheat varieties have been rendered ineffective due to the rapid evolution of the pathogen. To identify novel sources of adult plant resistance (APR), 292 accessions from the N.I. Vavilov Institute of Plant Genetic Resources, Saint Petersburg, Russia, were screened for known APR genes (i.e. Yr18, Yr29, Yr46, Yr33, Yr39 and Yr59) using linked polymerase chain reaction (PCR) molecular markers. Accessions were evaluated against Pst (pathotype 134 E16 A + Yr17 + Yr27) at seedling and adult plant stages across multiple years (2014, 2015 and 2016) in Australia. Phenotypic analyses identified 132 lines that potentially carry novel sources of APR to YR. Genome-wide association studies (GWAS) identified 68 significant marker–trait associations (P < 0.001) for YR resistance, representing 47 independent quantitative trait loci (QTL) regions. Fourteen genomic regions overlapped with previously reported Yr genes, including Yr29, Yr56, Yr5, Yr43, Yr57, Yr30, Yr46, Yr47, Yr35, Yr36, Yrxy1, Yr59, Yr52 and YrYL. In total, seven QTL (positioned on chromosomes 1D, 2A, 3A, 3D, 5D, 7B and 7D) did not collocate with previously reported genes or QTL, indicating the presence of promising novel resistance factors. Overall, the Vavilov diversity panel provides a rich source of new alleles which could be used to broaden the genetic bases of YR resistance in modern wheat varieties.

Highlights

Wheat is one of the most widely cultivated cereal crops worldwide, with an annual production of approximately 761 million tonnes (Crop Prospects and Food situation 2020)
Seven new quantitative trait loci (QTL) for YR resistance were identified on chromosomes 1D, 2A, 3A, 3D, 5D, 7B and 7D
These genomic regions were associated with different levels of resistance across the three years of field assessments. qNV.Yr-2A.5 and qNV.Yr-5D were associated with resistance in 2014 and 2015, while other QTL were detected only in a single environment

Summary

Introduction

Wheat is one of the most widely cultivated cereal crops worldwide, with an annual production of approximately 761 million tonnes (Crop Prospects and Food situation 2020). Global wheat yields are threatened by climate change (Asseng et al 2015; Barlow et al 2015) and rapidly evolving pathogens causing serious outbreaks of diseases, including rusts (Chaves et al 2013). Tritici (Pst) is an economically important disease that has caused several major epidemics worldwide, resulting in significant production losses (Sanin and Nazarova 2010; Hovmoller et al 2011; Ellis et al 2014b; Xia et al 2016a; Rahmatov 2016; Ali et al 2017). Deployment of YR-resistant varieties is the preferred method of rust disease management because it is cost-effective and reduces the reliance on fungicides (Chen 2005a)

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