Detection of QTLs for traits associated with pre-harvest sprouting resistance in bread wheat (<i>Triticum aestivum</i> L.)

Abstract

Pre-harvest sprouting (PHS) is one of the serious problems for wheat production, especially in rainy regions. Although seed dormancy is the most critical trait for PHS resistance, the control of heading time should also be considered to prevent seed maturation during unfavorable conditions. In addition, awning is known to enhance water absorption by the spike, causing PHS. In this study, we conducted QTL analysis for three PHS resistant related traits, seed dormancy, heading time and awn length, by using recombinant inbred lines from ‘Zenkouji-komugi’ (high PHS resistance) × ‘Chinese Spring’ (weak PHS resistance). QTLs for seed dormancy were detected on chromosomes 1B (QDor-1B) and 4A (QDor-4A), in addition to a QTL on chromosome 3A, which was recently cloned as TaMFT-3A. In addition, the accumulation of the QTLs and their epistatic interactions contributed significantly to a higher level of dormancy. QDor-4A is co-located with the Hooded locus for awn development. Furthermore, an effective QTL, which confers early heading by the Zenkouji-komugi allele, was detected on the short arm of chromosome 7B, where the Vrn-B3 locus is located. Understanding the genetic architecture of traits associated with PHS resistance will facilitate the marker assisted selection to breed new varieties with higher PHS resistance.

Genome-wide association study of pre-harvest sprouting resistance in Chinese wheat founder parents

“… Hoshino et al (1989) found that a large vernalization requirement delays germination in winter wheat areas where the late wheat is subjected to ear sprouting by monsoon rain. Cao et al (2016) also detected a QTL associated with PHS resistance on the short arm of Chr. 7B where Vrn-B3 is located.…”

Genome-Wide Association Study for Pre-harvest Sprouting Resistance in a Large Germplasm Collection of Chinese Wheat Landraces

“…These studies have either evaluated PHS resistance directly by testing whole intact spikes in misting chambers or simulated rain events in the field (Somyong et al, 2014; Albrecht et al, 2015), or germination testing of harvest-ripe grain under controlled conditions (Somyong et al, 2014; Zhang et al, 2014; Lin et al, 2015). According to biparental genetic linkage analyses, all 21 chromosomes of wheat reportedly harbor QTL for PHS resistance (Mohan et al, 2009; Cabral et al, 2014; Cao et al, 2016; Fakthongphan et al, 2016), but the most consistently detected regions are located on the group three chromosomes (Kato et al, 2001; Osa et al, 2003; Kulwal et al, 2004; Mori et al, 2005; Liu and Bai, 2010) and Chr 4A (Mares et al, 2005; Chen et al, 2008; Singh et al, 2010; Cabral et al, 2014). The PHS resistance genes underpinning the 3A, 3B, and 3D regions are considered to be tightly linked or pleiotropic with red seed coat color determined by dominant R alleles (Himi et al, 2011).…”

Allelic Impacts of TaPHS1, TaMKK3, and Vp1B3 on Preharvest Sprouting of Northern Great Plains Winter Wheats

“…The 3AS QTL has been shown to explain up to 58% of the phenotypic variation for PHS (Liu et al, 2008) and has been independently identified in multiple studies as a significant PHS QTL (Liu and Bai, 2010;Nakamura et al, 2011;Graybosch et al, 2013;Cao et al, 2016;Lin et al, 2016;and others). Nakamura et al (2011) established TaPHS1 (formerly termed TaMFT ) as a candidate gene for the 3AS PHS QTL and identified a single nucleotide polymorphism (SNP) mutation in its promoter that upregulated TaPHS1 expression.…”

“…Previous studies have identified quantitative trait loci (QTLs) significantly affecting PHS on most wheat chromosomes (reviewed by Flintham et al, 2002, andGao et al, 2013). A relatively small number of QTLs account for much of the genetic variability in sprouting variation, with the major QTLs being located on chromosomes 2B, 3A, and 4A (Graybosch et al, 2013, Cao et al, 2016. Some causal genes underlying significant QTLs have been identified and their effects on PHS have been partially characterized, including TaPHS1 (Nakamura et al, 2011, Liu et al, 2013, TaMKK3 (Torada et al, 2016), TaVP1 (Yang et al, 2007), TaSdr , and Tamyb10 (Wang et al, 2016, Lin et al, 2016.…”