Identification of genetic loci associated with ear-emergence in bread wheat

Abstract

A doubled haploid population constructed from a cross between the South Australian wheat cultivars 'Trident' and 'Molineux' was grown under winter field conditions, under field conditions over summer and under artificial light both with and without vernalisation. The duration from planting to ear-emergence was recorded and QTL associated with heading date were detected using a previously constructed genetic linkage map. Associations were shown with chromosomal regions syntenous to previously identified photoperiod (Ppd-B1) and vernalisation (Vrn-A1) sensitive loci. Additional QTL associated with time to heading were also identified on chromosomes 1A, 2A, 2B, 6D, 7A and 7B. Comparisons between the genetic associations observed under the different growing conditions allowed the majority of these loci to be classified as having either photoperiod-sensitive, vernalisation-sensitive or earliness per se actions. The identification of a photoperiod-sensitive QTL on chromosome 1A provides evidence for a wheat gene possibly homoeologous to Ppd-H2 previously identified on chromosome 1H of barley. The occurrence of a putative major gene for photoperiod sensitivity observed on chromosome 7A is presented. The combined additive effects at these loci accounted for more than half the phenotypic variance in the duration from planting to ear-emergence in this population. The possible role of these loci on the adaptation of wheat in Australia is discussed.

Preferential retention of chromosome regions in derived synthetic wheat lines: a source of novel alleles for wheat improvement

“…The 2BS region was associated with positive and negative effects on ANT, GW and GY in the present study; comparative mapping suggests that it is the same region as identified in several published studies, which contains QTLs for anthesis, height, grain weight and grain yield (Verma et al 2004;Quarrie et al 2005;Kuchel et al 2006;Rebetzke et al 2008;McIntyre et al 2010), and Ppd-B1 (Mohler et al 2004). Similarly, the 7BL region was associated with all four traits in this study.…”

“…Similarly, the 7BL region was associated with all four traits in this study. This also appears to be the same as the region identified as containing QTLs for anthesis and grain yield, by Kuchel et al (2006) and Quarrie et al (2005), respectively. In this study, a region on 1AL was associated with earlier flowering and reduced height; it appears to be the same as the anthesis QTL region identified by Kuchel et al (2006).…”

“…This also appears to be the same as the region identified as containing QTLs for anthesis and grain yield, by Kuchel et al (2006) and Quarrie et al (2005), respectively. In this study, a region on 1AL was associated with earlier flowering and reduced height; it appears to be the same as the anthesis QTL region identified by Kuchel et al (2006). The regions on 1BS, 3BS and 7AS appear to be the same as the heading date QTL region identified by Griffiths et al (2009); in our study, all three regions are associated with earlier flowering, in addition to both positive and negative effects on GW and GY.…”

“…They identified QTLs for grain weight on three chromosomes (1A, 3D, 4B). Comparative mapping suggests that the QTL on 1A is in the same region as the anthesis QTL identified by Kuchel et al (2006) and the region preferentially retained in the present study, which is also associated with anthesis. The QTL on 4B is also located in a similar region to the region preferentially retained and associated with GW and HT in the Altar84/Ae.…”

Quantitative Trait Loci for Grain Yield and Adaptation of Durum Wheat (Triticum durum Desf.) Across a Wide Range of Water Availability

“…QTL were considered common to different environments when the corresponding chromosome peak positions were located within 20 cM. QHd.idw-3B QPht.idw-3A Kuchel et al 2006). It is worth noting that one of the major QTL detected in our study on chr.…”