Genetic Elucidation of Glucosinolates in a Diverse Collection of Indian Mustard (Brassica juncea L.) ^†

Abstract

Glucosinolates (GSLs) are secondary metabolites produced by members of the genus Brassica. These compounds impart the pungency to brassica vegetables and oils. Due to their health benefits, which include anti-cancer and anti-fungal properties, they have been attracting interest in research. Indian mustard (B. juncea L.), used as condiment and oil crop has high natural levels of seed glucosinolates and displays exploitable natural variation in this trait. In this study a diverse collection of 161 mustard lines originating from 21 countries, will be genotyped and phenotyped. Traits of interest include seed GSLs (sinigrin, gluconapin, progroitin, epi-progoitin and glucoiberin), oil and protein content, as well as basic agro-morphological performance such as height, flowering time and yield. Current knowledge on GSL biosynthesis and its genetic regulation mostly relies on data from Arabidopsis thaliana. We aim to elucidate the genetic architecture of GSL content and composition in relation to other seed traits (oil and protein content) in our diversity panel through association mapping. Additionally, we are aiming to resolve genome complexity of GSL genes in mustard genome in contrast to A. thaliana by identifying gene copy number through in silico analysis. Outcome of this study will help streamline the breeding and product development for either high GSL mustard lines for condiment use or low GSL lines for canola-type oil use. Our preliminary data on seed GSLs seems to reflect the historical use of mustard in different geographical regions. Chinese and European lines featured higher GSL while lines from the Indian subcontinent displayed lower GSL contents.