Molecular Mapping of Stripe Rust Resistance in Hard Red Winter Wheat TAM 111 Adapted to the U.S. High Plains

Abstract

Stripe rust, also known as yellow rust, caused by Puccinia striiformis Westend. f. sp. tritici Erikss. (Pst), is one of the most important foliar diseases of wheat (Triticum aestivum L.) in the United States and other parts of the world. To investigate the genetic basis of resistance conferred by the winter wheat cultivar ‘TAM 111’, a mapping population of 124 F5 and F6 derived recombinant inbred lines (RILs) developed from the cross of ‘TAM 112’/TAM 111 was evaluated against Pst populations in eight environments in the United States and against predominant race PST‐100 in the greenhouse. The RIL population was further genotyped with Diversity Arrays Technology, simple sequence repeats and sequence tagged sites markers. A major quantitative trait locus (QTL), QYr.tam‐2BL, was identified on the long arm of chromosome 2B, which is found to be associated with resistance to stripe rust in TAM 111. QYr.tam‐2BL was identified in five out of the eight environments (Arkansas 2012, Arizona 2010, Castroville, TX, 2010, Mt. Vernon, WA, 2010 and Pullman, WA, 2011) as well as in the greenhouse, and explained 13 to 63% of the total phenotypic variation in severity across the environments. The QTL was also detected in seedling and adult plant stages with race PST‐100 under controlled greenhouse conditions. Based on the available evidence, QYr.tam‐2BL probably represents a previously uncharacterized gene on 2BL. Minor QTL on chromosomes 1A, 2A, 6B, and 7D were also detected inconsistently across environments. Because the effectiveness of QYr.tam‐2BL was observed to be environmentally dependent and probably race‐specific, it is suggested to combine this locus with effective major genes or adult plant resistance genes to increase its usefulness.

Developing KASP Markers on a Major Stripe Rust Resistance QTL in a Popular Wheat TAM 111 Using 90K Array and Genotyping‐by‐Sequencing SNPs

“…The number of the environment-specific minor QTL for quantitative stripe rust resistance identified in the current study with high-resolution maps is higher than the ones identified by Basnet et al (2014). In addition to the major QTL on chromosome 2B, seven minor QTL on chromosomes 1A, 2A, 4A, 4B, 6B, and 7D were identified, which confirmed those five QTL identified by Basnet et al (2014), and the other two were novel.…”

“…The major QTL on the long arm of chromosome 2B, previously designated as QYr.tam-2BL (Basnet et al, 2014;Fig. 1A), was the most important resistance loci identified in TAM 111 in the current study.…”

“…There are four consistent QTL on chromosomes 2A, 2B, 4A, and 4B from both analyses of MapQTL and QTLNetwork, but the two QTL on 4A and 4B were new compared with QTL from the previous analysis by Basnet et al (2014) (Table 1, Supplemental Tables S2 and S3). The QTL QYr.tamu-2A1 and QYr.tamu-2B could decrease both DS and IT with favorable alleles from TAM 111, whereas the marker linkage for DS was not significant from QTLNetwork at P < 0.05.…”

“…However, a few cultivars, including TAM 111, remained resistant against the Yr17 virulent race (Basnet et al, 2014). However, a few cultivars, including TAM 111, remained resistant against the Yr17 virulent race (Basnet et al, 2014).…”

“…However, a few cultivars, including TAM 111, remained resistant against the Yr17 virulent race (Basnet et al, 2014). Basnet et al (2014) conducted diversity arrays technology (DArT) genotyping (Akbari et al, 2006) of the two parents and 92 randomly selected recombinant inbred lines (RILs) developed from TAM 112/TAM 111. Integrated deployment of major seedling resistance genes in conjunction with adult plant resistance is an effective strategy to combat stripe rust resistance.…”