QTL analysis for grain weight in common wheat

Abstract

Quantitative trait loci (QTL) analysis for grain weight (GW = 1000 grain weight) in common wheat was conducted using a set of 100 recombinant inbred lines (RILs) derived from a cross 'Rye Selection 111 (high GW) × Chinese Spring (low GW)'. The RILs and their two parental genotypes were evaluated for GW in six different environments (three locations × two years). Genotyping of RILs was carried out using 449 (30 SSRs, 299 AFLP and 120 SAMPL) polymorphic markers. Using the genotyping data of RILs, framework linkage maps were prepared for three chromosomes (1A, 2B, 7A), which were earlier identified by us to carry important/major genes for GW following monosomic analysis. QTL analysis for GW was conducted following genome-wide single marker regression analysis (SMA) and composite interval mapping (CIM) using molecular maps for the three chromosomes. Following SMA, 12 markers showed associations with GW, individual markers explaining 6.57% to 10.76% PV (phenotypic variation) for GW in individual environments. The high grain weight parent, Rye Selection111, which is an agronomically superior genotype, contributed favourable alleles for GW at six of the 12 marker loci identified through SMA. The CIM identified two stable and definitive QTLs, one each on chromosome arms 2BS and 7AS, which were also identified through SMA, and a third suggestive QTL on 1AS. These QTLs explained 9.06% to 19.85% PV for GW in different environments. The QTL for GW on 7AS is co-located with a QTL for heading date suggesting the occurrence of a QTL having a positive pleiotropic effect on the two traits. Some of the markers identified during the present study may prove useful for marker-assisted selection, while breeding for high GW in common wheat.

QTL analysis for some quantitative traits in bread wheat

“…However, none of the individual QTL was detected in both populations. Wang et al, 1999;Kulwal et al, 2004;2005a;Yang et al, 2005;Kumar et al, 2007 PIII PHST Single-locus (CIM) QTL Cartographer Wang et al, 2004;Kulwal et al, 2005b PIV GW Single-locus (SMA, CIM) QTL Cartographer Wang et al, 2004;Kumar et al, 2006 GPC: Grain protein content; PHST: Pre-harvest sprouting tolerance; GW: Grain weight; SMA: Single marker analysis, SIM: Simple interval mapping, CIM: Composite interval mapping, MCIM: Multiple-trait composite interval mapping M-QTL: In each of the two mapping populations, 5 M-QTL for GPC were detected, which accounted for a mere 7.22% (PII) to 7.24% (PI) of the phenotypic variation. The desirable alleles for high GPC were distributed in both the parents of the two populations studied.…”

“…Two of 3 QTL (QGw.ccsu-2B.1 and QGw.ccsu-7A.1) were definitive and were detected in at least 4 different environments and also in the pooled environment. The individual QTL explained 9.06% to 19.85% phenotypic variation (Kumar et al, 2006).…”

QTL mapping of 1000-kernel weight, kernel length, and kernel width in bread wheat (Triticum aestivum L.)

“…In earlier studies, genomic regions associated with kernel weight and dimensions have been identified using monosomic (Giura and Saulescu 1996;Varshney et al 2000) and QTL analysis (Campbell et al 1999;Ammiraju et al 2001 andDholakia et al 2003;Kumar et al 2006;Breseghello and Sorrells 2007). Breseghello and Sorrells (2006) studied the association of these kernel traits with simple sequence repeat (SSR) markers in a collection of wheat cultivars, whereas Röder et al (2008) performed fine mapping of a grain weight QTL at the telomeric region of chromosomal arm 7DS.…”

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 …”