Quantitative Trait Loci Associated with Kernel Traits in a Soft × Hard Wheat Cross

Abstract

Kernel morphology and texture influence the value of wheat (Triticum aestivum L.). The objectives of this study were to determine associations between kernel traits and molecular markers and to identify quantitative trait loci (QTLs) affecting kernel traits in a soft × hard white wheat cross. Seventy eight F~-derived recombinant inbred lines (RILs) from cross be tween the so ft wh ite wh eat NY 6432-18 (NY18) and the hard white wheat 'Clark's Cream' (CC) were developed by single seed descent. Kernel texture was measured by near infrared reflectance (NIR) on RIL grain samples from six environments. Digital image analysis (DIA) was used to measure kernel length, width, area, perimeter on grain samples from four environments. Test weight and thousand kernel weight (TKW) were also determined. Shape factor and density factor were calculated. The map for this population consisted of 313 molecular markers in 47 linkage groups located on all wheat homoeologous chromosome groups. Linkage groups that mapped to wheat homoeologous group 2 chromosomes were highly skewed towards NY18 alleles. Genotype effects and genotype × environment interactions were highly significant for most traits. QTLs for kernel width and kernel length also influenced kernel area and TKW, but did not influence each other. The pinB marker at the puroindoline B locus on chromosome 5DS explained over 60% of the phenotypic variation for kernel texture. QTLs for kernel traits were located on chromosomes IA, 2B, 2D, 3B, 7A, and 7B. Tm HE ECONOMIC VALUE of the U.S. wheat crop is deterined by class, which depends in part on kernel morphology and texture, and by test weight. Inspectors for the U.S. Grain Inspection, Packers and Stockyards Administration use color, shape, and length of the kernel and shape of the germ, crease, and brush to determine wheat grain classes (GIPSA, 1997). In general, hard wheat kernels are long, narrow, and translucent while soft kernels are short, rounded, and chalky in appearance. Hybridization between classes reduces the correlation between kernel morphology and wheat class and reduces the accuracy of the current classification

AB-QTL analysis in winter wheat: I. Synthetic hexaploid wheat (T. turgidum ssp. dicoccoides × T. tauschii) as a source of favourable alleles for milling and baking quality traits

“…Genes for puroindoline a (Pina-D1), puroindoline b (Pinb-D1) and grain softness related proteins (Gsp-D1) at the Ha locus have been associated with the expression of grain hardness (Tranquilli et al 1999). The Ha locus was found to have a strong influence on milling yield (Campbell et al 1999). Consistent with this result, Martin et al (2001) and Nelson et al (2006) both detected strong negative correlations between grain hardness and milling yield.…”

A Genetic Framework for Grain Size and Shape Variation in Wheat

“…Homoeologous group 3, especially chromosome 3A, has a strong effect both on grain size and shape across the DH populations studied here, yet QTL for related traits (grain length and area) have been reported only in one previously studied population on chromosome 3B (Campbell et al, 1999). The QTL for grain size and shape on chromosome 3A identified in this analysis are of particular interest since their mapping intervals coincide with the approximate position of the sphaerococcum locus (Salina et al, 2000).…”

“…Previous studies used a limited number of metrics that were analyzed discretely largely in single mapping populations (Giura and Saulescu, 1996;Campbell et al, 1999;Dholakia et al, 2003;Breseghello and Sorrels, 2007;Sun et al, 2009). This approach identifies only pairwise associations between traits and single-trait genetic effects; therefore, it is limited in providing a comprehensive model for the phenotypic and genetic structure of the quantitative traits.…”

Detection of QTLs Associated to Some Grain Traits in Bread Wheat (Triticum aestivum L.), Using Association Mapping

“…Giura and Saulescu, 1996;Varshney et al, 2000 ) ‫کیو.تی.ال‬ ‫تجزیه‬ ‫و‬ ( Ammiraju et al, 2001 and2004;Dholakia et al, 2003;Kumar et al, 2006;Sorrells, 2006 and Campbell et al, 1999;Perretant et al, 2000;Galande et al, 2001;Igrejas et al, 2002;Narasimhamoorthy et al, 2006 …”