Positional Cloning of the Flowering Time QTL qFT12-1 Reveals the Link Between the Clock Related PRR Homolog With Photoperiodic Response in Soybeans.

Yuqiu Li,Zhengjun Xia,Jiayin Yang,Hong Zhai,Yingshan Dong,Bo Hu,Hongyan Wu

doi:10.3389/fpls.2019.01303

Abstract

Flowering time and maturity are important agronomic traits for soybean cultivars to adapt to different latitudes and achieve maximal yield. Genetic studies on genes and quantitative trait loci (QTL) that control flowering time and maturity are extensive. In particular, the molecular bases of E1-E4, E6, E9, E10, and J have been deciphered. For a better understanding of regulation of flowering time gene networks, we need to understand if more molecular factors carrying different biological functions are also involved in the regulation of flowering time in soybeans. We developed a population derived from a cross between a landrace Jilincailihua (male) and a Chinese cultivar Chongnong16 (female). Both parents carry the same genotypes of E1e2E3HaE4 at E1, E2, E3, and E4 loci. Nighty-six individuals of the F2 population were genotyped with Illumina SoySNP8k iSelect BeadChip. A total of 2,407 polymorphic single nucleotide polymorphism (SNP) markers were used to construct a genetic linkage map. One major QTL, qFT12-1, was mapped to an approximately 567-kB region on chromosome 12. Genotyping and phenotyping of recombinant plant whose recombination events were occurring within the QTL region allowed us to narrow down the QTL region to 56.4 kB, in which four genes were annotated. Allelism and association analysis indicated Glyma.12G073900, a PRR7 homolog, is the strongest candidate gene for qFT12-1. The findings of this study disclosed the possible involvement of circadian clock gene in flowering time regulation of soybeans.

Highlights

Soybeans are an important crop globally and provide quality protein and oil for human and animal consumption (Graham and Vance, 2003)
After exclusion of rare allele or unmapped markers, a total of 2,407 single nucleotide polymorphism (SNP) markers were genetically mapped to 20 linkage groups corresponding to the 20 chromosomes of soybeans with quantitative trait loci (QTL) IciMapping 4.0 software (Meng et al, 2015) (Figures 2A, B; Supplementary Table S5–7)
The result indicated JLCLH allelic type widely exists in Glycine soja while CN16 allelic type is wide distributed in improved cultivars, especially from Northern part of China. 182 of 333 accessions have maturation data, we found 149 accessions are from maturity group 000 to IV, in contrast, only 33 accessions are from maturity group V to X

Summary

Introduction

Soybeans are an important crop globally and provide quality protein and oil for human and animal consumption (Graham and Vance, 2003). Molecular bases of flowering and maturity genes are important for understanding the mechanism regulating photoperiodic response and adaptation in soybeans (Zhao et al, 2016). Flowering time and maturity regulated by photoperiod sensitivity genes or loci (Garner and Allard, 1927; Cober et al, 2014) have been reported for soybeans, E1, E2 (Bernard, 1971), E3 (Buzzell, 1971), E4 (Buzzell and Voldeng, 1980), E5 (McBlain and Bernard, 1987), E6 (Bonato and Vello, 1999), E7 (Cober and Voldeng, 2001), E8 (Cober et al, 2010), E9 (Kong et al, 2014), E10 (Samanfar et al, 2017), and J (Ray et al, 1995). Seven QTLs for flowering time (R1) were mapped to a rather large region of 28.2–45 cm on chromosome 12(LG H) (Kuroda et al, 2013; Lu et al, 2016; Fang et al, 2017; Mao et al, 2017; Liu et al, 2018); the molecular identities of these QTLs are still unknown

Methods

Findings

Discussion

Conclusion