Association Mapping of Agronomic traits in Bread Wheat using a high Density 90k SNP Array

A genome-wide association study (GWAS) was performed using a high-density infinium 90K SNP array. We identified a total markers traits associations (MTAs) (p ?0.000) for the following plant traits; days taken to 50% heading(DH), days to 50% maturity (DM), plant height (Ph) cm, flag leaf area cm2 (FLA), tillers number per plant, spike length (SL) cm and grain yield per plant (GP) g. Most of the SNPs were identified in the A and B genome as compared to the D genome. The significant associated SNPs were mainly distributed on the chromosome 2B, 3B, 5A, and 5B. Nine SNPs on chromosome 5A, 2B and 2D were identified having pleiotropic effects The correlation analysis showed a significant positive association among SL, NT, GP. Which depicted that these traits are promising for breeding high yielding wheat cultivars. This study provided useful information of the valuable genetic loci for marker-assisted breeding.

Genome-wide Mapping of Loci for Adult-plant Resistance to Stripe Rust in Durum Wheat Svevo Using the 90K SNP Array

Stripe rust is a foliar disease in wheat caused by Puccinia striiformis f. sp. tritici (Pst). The best way to protect wheat from this disease is growing resistant cultivars. Tetraploid wheat can serve as a good source of valuable genetic diversity for various traits. Here we report the mapping of nine stripe rust resistance quantitative trait loci (QTL) effective against Pst in China and Israel. We used recombinant inbred lines (RILs) developed from a cross between durum wheat (Triticum turgidum ssp. durum) cultivar Svevo and wild emmer wheat (T. dicoccoides) accession Zavitan. By genotyping the RIL population of 137 lines using the wheat 90K SNP array, we mapped an adult-plant resistance locus QYrsv.swust-1BL.1, the most effective QTL, within a 0.75 cM region on chromosome arm 1BL of Svevo, corresponding to the region of 670.7 to 671.5 Mb on the Chinese Spring chromosome arm 1BL. Of the other eight minor effect stripe rust QTL, seven were from Svevo and mapped on chromosomes 1A, 1B, 2B, 3A, 4A, and 5A; and one was from Zavitan and mapped on chromosome 2A. Several QTL with epistatic effects were identified as well. The markers linked to the resistance QTL can be useful in marker-assisted selection for incorporation of these resistance QTL into both durum and common wheat cultivars.