QTL Mapping of Seed Glucosinolate Content Responsible for Environment in Brassica napus.

Yajun He,Dingxue Hu,Ying Fu,Dayong Wei,Wei Qian

doi:10.3389/fpls.2018.00891

Abstract

Glucosinolates (GSLs) are a major class of secondary metabolites. The content of seed GSL is largely regulated by environments in rapeseed (Brassica napus). However, the genetic control of seed GSL content responsible for environment in B. napus has been poorly understood. In the current study, a doubled haploid (DH) population from a cross between winter and semi-winter lines of rapeseed was grown in two distinct eco-environments, Germany and China, to evaluate the eco-environment effect and dissect the quantitative trait loci (QTL) responsible for environment for seed GSL in rapeseed. The deviation value of GSL content between eco-environments (GSLE) was calculated for each line in the DH population and the QTLs for GSLE were detected. GSLE ranged from −46.90 to 36.13 μmol g−1 meal in the DH population, suggesting the prominent eco-environmental effects for seed GSL in rapeseed. Four QTLs for GSLE were identified on chromosomes A04, A06, and A09 explaining 4.70∼9.93% of the phenotypic variation. Comparison of QTLs of seed GSL content between different eco-environments found three QTLs for GSL on A02 from 37.6 to 45.4 cM, A04 from 0 to 17.2 cM, and A09 from 67.0 to 98.6 cM exhibited significant difference of QTL effect between the German and Chinese eco-environments (P < 0.01), indicating the environment sensibility of these loci on seed GSL content. Moreover, flowering time (FT), an important environment adaptation trait in plant, was also investigated in this study. Comparative QTL analysis among GSLE, GSL, and FT revealed that three regions on chromosomes A02, A04, and A09 not only exhibited significant differences in QTL effect between Germany and China, but also co-located with the QTL intervals of GSLE and FT. Our results revealed that most of the GSL loci can influence GSL accumulation under different eco-environments, whereas the three QTL intervals on A02, A04, and A09 might be sensitive to the eco-environments for seed GSL content.

Highlights

Continuous segregation was found for GSL content between eco-environments (GSLE) in the doubled haploid (DH) population
The GSLE exhibited a mean value of 14.02 μmol g−1 meal, which ranged from −46.90 to 36.13 μmol g−1 meal in the DH population when the eco-environments changed from China to Germany (Table 1)
The broad deviation of DH lines across eco-environments confirmed the environmental effect on seed GSL content

Summary

Introduction

Glucosinolates (GSLs) are a major class of secondary metabolites in the Brassicaceae family, such as rapeseed, one of most important oil crops producing edible oil for human diet and protein-rich feed for animals (Wittstock and Halkier, 2000; Bak and Feyereisen, 2001; Leckband et al, 2002; Mikkelsen et al, 2004; Piotrowski et al, 2004; Grubb and Abel, 2006; Halkier and Gershenzon, 2006; Hirai et al, 2007; Francisco et al, 2009; Wanasundara, 2011; Dimov et al, 2012). Quantitative trait loci (QTL) for total seed GSL content have been identified in rapeseed (Uzunova et al, 1995; Howell et al, 2003; Sharpe and Lydiate, 2003; Zhao and Meng, 2003; Basunanda et al, 2007; Hasan et al, 2008; Harper et al, 2012; Javidfar and Cheng, 2013; Li et al, 2014; Fu et al, 2015). Little work has been performed on the deviation of GSL content between eco-environments (GSLE) in Brassica napus

Objectives

Methods

Results

Conclusion