Genome-wide association analysis for stripe rust resistance in spring wheat (Triticum aestivum L.) germplasm

Abstract

Stripe rust is a continuous threat to wheat crop all over the world. It causes considerable yield losses in wheat crop every year. Continuous deployment of adult plant resistance (APR) genes in newly developing wheat cultivars is the most judicious strategy to combat this disease. Herein, we dissected the genetics underpinning stripe rust resistance in Pakistani wheat germplasm. An association panel of 94 spring wheat genotypes was phenotyped for two years to score the infestation of stripe rust on each accession and was scanned with 203 polymorphic SSRs. Based on D´ measure, linkage disequilibrium (LD) exhibited between loci distant up to 45 cM. Marker-trait associations (MTAs) were determined using mixed linear model (MLM). Total 31 quantitative trait loci (QTLs) were observed on all 21 wheat chromosomes. Twelve QTLs were newly discovered as well as 19 QTLs and 35 previously reported Yr genes were validated in Pakistani wheat germplasm. The major QTLs were QYr.uaf.2AL and QYr.uaf.3BS (PVE, 11.9%). Dissection of genes from the newly observed QTLs can provide new APR genes to improve genetic resources for APR resistance in wheat crop.

Keywords

• wheat
• Puccinia striiformis
• LD
• GWAS
• MTA
• PCoA