Detection of QTLs for seedling characteristics in barley (Hordeum vulgare L.) grown under hydroponic culture condition

Abstract

BackgroundSeedling characteristics play significant roles in the growth and development of barley (Hordeum vulgare L.), including stable stand establishment, water and nutrients uptake, biotic resistance and abiotic stresses, and can influence yield and quality. However, the genetic mechanisms underlying seedling characteristics in barley are largely unknown and little research has been done. In the present work, 21 seedling-related characteristics are assessed in a barley double haploid (DH) population, grown under hydroponic conditions. Of them, leaf age (LAG), shoot height (SH), maximum root length (MRL), main root number (MRN) and seedling fresh weight (SFW) were investigated at the 13th, 20th, 27th, and 34th day after germination. The objectives were to identify quantitative trait loci (QTLs) underlying these seedling characteristics using a high-density linkage map and to reveal the QTL expression pattern by comparing the QTLs among four different seedling growth stages.ResultsA total of 70 QTLs were distributed over all chromosomes except 4H, and, individually, accounted for 5.01%–77.78% of phenotypic variation. Out of the 70 detected QTLs, 23 showed a major effect on 14 seedling-related characteristics. Ten co-localized chromosomal regions on 2H (five regions), 3H (two regions) and 7H (three regions) involved 39 QTLs (55.71%), each simultaneously influenced more than one trait. Meanwhile, 9 co-localized genomic regions involving 22 QTLs for five seedling characteristics (LAG, SH, MRL, MRN and SFW) at the 13th, 20th, 27th and 34th day-old seedling were common for two or more growth stages of seedling. QTL in the vicinity of Vrs1 locus on chromosome 2H with the favorable alleles from Huadamai 6 was found to have the largest main effects on multiple seedling-related traits.ConclusionsSix QTL cluster regions associated with 16 seedling-related characteristics were observed on chromosome 2H, 3H and 7H. The majority of the 29 regions identified for five seedling characteristics were selectively expressed at different developmental stages. The genetic effects of 9 consecutive expression regions displayed different developmental influences at different developmental stages. These findings enhanced our understanding of a genetic basis underlying seedling characteristics in barley. Some QTLs detected here could be used for marker-assisted selection (MAS) in barley breeding.Electronic supplementary materialThe online version of this article (10.1186/s12863-017-0562-y) contains supplementary material, which is available to authorized users.

Mapping dynamic QTL dissects the genetic architecture of grain size and grain filling rate at different grain-filling stages in barley

“…For example, certain major consensus QTLs tightly linked to 2_527241334 at 126 cM for grain filling rate and grain size detected here, are likely the same to seedling traits QTL qSH2-191 and qSFW2-191 identified by Wang et al . 61 and also likely same to the qSms2-7 and qTgw2-1 for yield-related traits reported by Wang et al . 29 .…”

“…3, Table 6). The vrs1 gene was detected in this region, which was reported in previous studies to control row-number phenotype, affecting grain size and thousand grain weight traits 29,57,61,62 . The Nud gene controlling the hulled/naked caryopsis was detected within QTL cluster affecting GFR, GFR max , GA, GP, GL, GW and GD in interval 56.5–70 cM on chromosome 7H, and QTLs affected TGW were located at this locus 71 .…”

Dissecting the Genetic Basis of Grain Size and Weight in Barley (Hordeum vulgare L.) by QTL and Comparative Genetic Analyses

“…A doubled haploid (DH) population containing 122 lines derived from Huaai 11 (six-rowed and naked) and Huadamai 6 (two-rowed and hulled) was employed to identify QTLs that control barley grain size and weight. Details of the DH population and their parents can be found in our earlier studies (Ren et al, 2010; Wang et al, 2017). The DH lines and parents were evaluated in natural field conditions over three crop seasons (2015 to 2016, 2016 to 2017 and 2017 to 2018 seasons) in the experimental farm of Huazhong Agricultural University, Wuhan, China (30°48’N, 114°36’E), in a randomized complete block design with three replicates.…”

Quantitative Trait Loci Mapping for Vigour and Survival Traits of Barley Seedlings after Germinating under Salinity Stress

“…Evaluation of entries from both sets of barley germplasm for seedling survival and seedling vigour was conducted on germinated seeds in a glasshouse with a controlled temperature level set to a maximum level of ~24 • C using a hydroponic system [5,30], (Figure S1). Approximately 150 plump and uniform barley seeds per genotype were selected and surface sterilised in 10% sodium hypochlorite solution for ~5 min [27].…”

“…The seedling stage is one of the most important phases in barley growth and development and is determined by seed germination. It governs production aspects including uniform stand, good nutrients uptake, environmental stresses tolerance and yield [5]. Germination is a stage prompted by water uptake into the embryo leading to root and shoot emergence.…”