Molecular and field characterization of exotic spring wheat germplasm for disease resistance genes and yield

Abstract

Wheat (Triticum aestivum L.) is major cereal crop that contributes the nutrient requirements of about 35% world population having high contents of starch, proteins, and vitamins. Wheat in Pakistan is prone to many biotic and abiotic factors. Stripe rust (biotic factor) caused by pathogen Puccinia striiformis f. sp. tritici (Pst) is a major threat for wheat cause loss in yield and grain quality in many countries. To control the disease, genetic resistance is the most effective method that can be attained by identifying the resistant genetic regions through wheat genome mapping. Mapping the resistant loci and their association with traits is highly exploited in this era. Major aim of current research was to evaluate 200 exotic spring wheat advanced lines with 4 local check varieties in field for yield characteristics and disease reaction. Also, the gene postulation for stripe rust resistant genes with the help of DNA markers was carried out. The DNA markers genotyped were also used for association mapping with yield related traits. The 200 exotic spring wheat advance lines were evaluated for phenotypic correlation of fifteen morphological traits. PCA analysis revealed positive correlation among yield per plant with Flowers per spike and number of tillers. Total 38 SSRs markers were applied on 204 wheat genotypes against fifteen stripe rust resistance genes; Yr5, Yr15, Yr17, Yr18, Yr26, Yr36, Yr46, Yr48, Yr54, Yr59, Yr60, Yr61, Yr62, Yr64 and Yr65 genes Markers revealed higher diversity based on Polymorphic Information Content (PIC) value. In addition to disease resistance, 23 out of 38 markers were also associated with growth and yield traits of wheat genotypes studied. Clustering based on virulence data grouped contemporary isolates together and revealed high genetic diversity among lines. The present research findings can be exploited for increased yield and disease resistant capability of studied wheat lines.