Mapping Quantitative Trait Loci for Soybean Seedling Shoot and Root Architecture Traits in an Inter-Specific Genetic Population.

Silvas J Prince,J Grover Shannon,Babu Valliyodan,Tri D Vuong,Henry T Nguyen,Xiaolei Wu,Fang Lu,Siva P Kumpatla,Yonghe Bai

doi:10.3389/fpls.2020.01284

Abstract

Wild soybean species (Glycine soja Siebold & Zucc.) comprise a unique resource to widen the genetic base of cultivated soybean [Glycine max (L.) Merr.] for various agronomic traits. An inter-specific mapping population derived from a cross of cultivar Williams 82 and PI 483460B, a wild soybean accession, was utilized for genetic characterization of root architecture traits. The objectives of this study were to identify and characterize quantitative trait loci (QTL) for seedling shoot and root architecture traits, as well as to determine additive/epistatic interaction effects of identified QTLs. A total of 16,469 single nucleotide polymorphisms (SNPs) developed for the Illumina beadchip genotyping platform were used to construct a high resolution genetic linkage map. Among the 11 putative QTLs identified, two significant QTLs on chromosome 7 were determined to be associated with total root length (RL) and root surface area (RSA) with favorable alleles from the wild soybean parent. These seedling root traits, RL (BARC_020495_04641 ~ BARC_023101_03769) and RSA (SNP02285 ~ SNP18129_Magellan), could be potential targets for introgression into cultivated soybean background to improve both tap and lateral roots. The RL QTL region harbors four candidate genes with higher expression in root tissues: Phosphofructokinase (Glyma.07g126400), Snf7 protein (Glyma.07g127300), unknown functional gene (Glyma.07g127900), and Leucine Rich-Repeat protein (Glyma.07g127100). The novel alleles inherited from the wild soybean accession could be used as molecular markers to improve root system architecture and productivity in elite soybean lines.

Highlights

Soybean [Glycine max (L.) Merr.] is a major oil crop that plays a key role in food and industrial production (Tran and Mochida, 2010)
The recombinant inbred lines (RIL) mapping population developed from a cross of these parental lines showed a transgressive segregation for shoot-related traits (SL, plant height (PH)) and root traits like tap root length (TRL) (Table 2; Figure 2)
The RILs had longer or shorter shoot and root morphology compared to the G. max (Williams 82) and wild parent (PI 483460B), respectively (Table 2), for example: TRL (Figure 2) and root length (RL)

Summary

Introduction

Soybean [Glycine max (L.) Merr.] is a major oil crop that plays a key role in food and industrial production (Tran and Mochida, 2010). Wild soybeans represent a significant genetic resource with many rare alleles that are not present in cultivated soybean accessions (Lee et al, 2008; Mammadov et al, 2018). Previous studies using 397 diverse soybean accessions with maturity groups, III to IV (Prince et al, 2018) and III to VI (Prince et al, 2019), revealed that constitutive seedling traits, like total root length, root surface area, and lateral root number, are linked to grain yield under water limitation. Field studies in two different soil types that represent most of the U.S soybean growing target environments validated the association of root traits to grain yield under stress (Prince et al, 2016; Prince et al, 2019)

Objectives

Methods

Results

Discussion

Conclusion