Identification of quantitative trait loci for seedling root traits from Tibetan semi-wild wheat (Triticum aestivum subsp. tibetanum)

Abstract

As a primitive hexaploid wheat resource distributed only in Tibet, Tibetan semi-wild wheat (Triticum aestivum subsp. tibetanum Shao) possesses unique characteristics that could be exploited in wheat breeding programs. Its good root system could offer a stable platform for above-ground components. To detect possible excellent locus for root traits from Tibetan semi-wild wheat, we identified QTLs for root traits using a recombinant inbred line population derived from a cross between Tibetan semi-wild wheat Q1028 and Zhengmai 9023. A total of 15 QTLs on eight chromosomes were detected, including four major QTLs, QMrl.sau-7B, QTrl.sau-4B, QAd.sau-7A, and QSa.sau-4B. The phenotypic variation explained by each of these QTLs ranges from 5.67% to 16.68%. Positive alleles of six QTLs were derived from Q1028. Several novel QTLs for root traits were identified. In addition, significant correlations were detected amongst root traits and agronomic traits. Taken together, these results suggest that Tibetan semi-wild wheat and the newly identified novel QTLs could be useful in future breeding programs.

Genetic Screening for Mutants with Altered Seminal Root Numbers in Hexaploid Wheat Using a High-Throughput Root Phenotyping Platform

“…Despite the high plasticity ( e.g. , dynamic response to varying water, nutrient and environmental conditions) associated with root traits, we obtained a high heritability estimate for seminal root number measurements across the two screens, similar to previous estimates (Maccaferri et al 2016; Ma et al 2017). While this high heritability may be due to the controlled hydroponic environment used in these experiments (Figure 2), it nonetheless demonstrates that seminal root number is a stable phenotype under strong genetic control and can be targeted for selection to improve RSA in wheat breeding programs.…”

“…A sixth seminal root may also develop in some wheat varieties. A few quantitative trait loci (QTL) have been identified to underlie variation in seminal root number in wheat germplasm (Atkinson et al 2015; Maccaferri et al 2016; Ren et al 2012; Sanguineti et al 2007; Ma et al 2017; Iannucci et al 2017). However, many of these QTL are defined to broad intervals which makes their genetic dissection difficult and their use in breeding limited.…”

Genetic screening for mutants with altered seminal root numbers in hexaploid wheat using a high-throughput root phenotyping platform

“…Despite the high plasticity associated with root traits, we obtained high heritability estimates for the seminal root number measurements across different experiments, similar to estimates reported in other studies (Maccaferri et al 2016;Ma et al 2017). While these high heritability values may be due to the controlled hydroponic environment used in this experiment (Figure 1), it nonetheless demonstrates that seminal root number is a stable phenotype under strong genetic control and can be targeted for selection to improve RSA in wheat breeding programmes.…”

“…Typically, most wheat cultivars develop between 3 to 6 seminal roots (Araki and Iijima 2001). A few quantitative trait loci (QTL) have been identified to underlie variation in seminal root number in wheat germplasm (Atkinson et al 2015;Maccaferri et al 2016;Ren et al 2012;Sanguineti et al 2007;Ma et al 2017;Iannucci et al 2017). However, unlike other cereals (e.g.…”

Molecular Genetic Analysis of Drought Stress Response Traits in Brachypodium spp.

“…In this sense, the second cluster obtained in the hierarchical analysis (traits clustering) shows the association of some SSR markers with some characteristic of RSA (Figure 3). These results are very interesting since they can be used in future work for the identification of genes or QTLs related with the RSA, as has already been done in other species [20,[47][48][49].…”