Identification of QTLs Conferring Agronomic and Quality Traits in Hexaploid Wheat

Abstract

The availability of elite germplasm resources with high yield and quality potentials is very important for development of cultivars in wheat. Thus, seeking such resources has been the continuous effort of breeder community. In this study, genetic analysis of a novel resource, Triticum spelta line CSCR6, from Australia was made by use of a recombination inbred line (RIL) population of 82 individuals from the cross between CSCR6 and another Australian hexaploid wheat cultivar, Lang. Data of a multiple environmental test was employed to genetically dissect quantitative trait loci (QTL) for agronomic traits such as plant height (PH), spike length (SL), spikelet per spike (SPI), grain number per spike (GNS) and thousand grains weight (TGW) and for quality traits including grain protein content (GPC), gluten content (GC), grain hardness (GH), falling number (FN) and sedimentation value (SV). A 24 QTLs with additive effects were detected for all the investigated traits, and were located on chromosomes 1B, 1D, 2B, 3A, 3B, 3D, 4B, 5A, 5B, 7A, and 7B, respectively. Some QTLs located on 2B and 4B showed higher explanation of phenotypic variances and were not obviously interacted with environment. A QTL in the marker interval of wPT-5334-wPT-4918 (near the locus barc 0199) on 4B gave the highest contribution ratio of 30.76% on PH, while Qgpc-4B and Qgc-4B gave 13.07 and 14.70% contribution ratio on GPC and GC, respectively. Qph-2B, Qgns-2B, and Qgpc-2B showed 13.36, 10.00, and 10.79% contribution ratio on PH, GNS and GPC, respectively. Also, a QTL on 5A, Qsl-5A, could explain 25.12% of phenotypic variance on SL. For most of agronomic and quality traits, CSCR6 alleles produced increase effects. The fact that a number of loci affecting the investigated traits were detected in T. spelta line CSCR6 revealed that it could offer a new opportunity for the manipulation of these traits in wheat breeding programs.