Mapping quantitative trait loci for plant adaptation and morphology traits in wheat using single nucleotide polymorphisms

Wheat (Triticum aestivum L.) morphological and adaptation-related traits that are controlled by quantitative trait loci (QTLs) help define potential growing areas of a wheat cultivar. To dissect QTLs for heading date, lodging, shattering (SH), cold tolerance, plant height, spike length, spike compactness, awn length (AL) and chaff color (CC), a high-density genetic map with single nucleotide polymorphism and simple sequence repeat markers were developed using recombinant inbred lines (RILs) derived from 'Ning7840' x 'Clark'. The RILs were evaluated in eight Oklahoma environments from 2001 to 2004. A total of 31 QTLs with additive effects on different traits were mapped on most wheat chromosomes except for 1D, 3A, 3D, 4D, 6D, and 7B. Six chromosome regions showed either tightly linked QTLs or QTLs with pleiotropic effects for two to three traits. Five QTL pairs showed additive x additive effects (AA). Ten additive QTLs were involved in additive x environment (AE) effects, and one epistatic QTL was involved in AAE effects. Among nine traits evaluated only three (SH, AL, and CC) were controlled by single genes in this biparental population. Seven traits were conditioned by multiple QTLs. A total of 127 markers were tightly linked to the QTLs. The findings shed light on the inheritance of wheat morphological and adaptationrelated traits and provide DNA markers for manipulating these important traits to improve wheat production.