title: Metabolomics differentiation of canola genotypes: toward an understanding of canola allelochemicals.
abstract: Allelopathy is one crop attribute that could be incorporated in an integrated weed management system as a supplement to synthetic herbicides. However, the underlying principles of crop allelopathy and secondary metabolite production are still poorly understood including in canola. In this study, an allelopathic bioassay and a metabolomic analysis were conducted to compare three non-allelopathic and three allelopathic canola genotypes. Results from the laboratory bioassay showed that there were significant differences among canola genotypes in their ability to inhibit root and shoot growth of the receiver annual ryegrass; impacts ranged from 14% (cv. Atr-409) to 76% (cv. Pak85388-502) and 0% (cv. Atr-409) to 45% (cv. Pak85388-502) inhibition respectively. The root length of canola also differed significantly between genotypes, there being a non-significant negative interaction (r = -0.71; y = 0.303x + 21.33) between the root length of donor canola and of receiver annual ryegrass. Variation in chemical composition was detected between organs (root extracts, shoot extracts) and root exudates and also between canola genotypes. Root extracts contained more secondary metabolites than shoot extracts while fewer compounds were recorded in the root exudates. Individual compound assessments identified a total of 14 secondary metabolites which were identified from the six tested genotypes. However, only Pak85388-502 and Av-opal exuded sinapyl alcohol, p-hydroxybenzoic acid and 3,5,6,7,8-pentahydroxy flavones in agar growth medium, suggesting that the synergistic effect of these compounds playing a role for canola allelopathy against annual ryegrass in vitro.
authors.affiliation: School of Agricultural and Wine Sciences, Faculty of Science, Charles Sturt University Wagga Wagga, NSW, Australia ; Graham Centre for Agricultural Innovation, Charles Sturt University Wagga Wagga, NSW, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Asaduzzaman
authors.affiliation: School of Agricultural and Wine Sciences, Faculty of Science, Charles Sturt University Wagga Wagga, NSW, Australia ; Graham Centre for Agricultural Innovation, Charles Sturt University Wagga Wagga, NSW, Australia.
authors.forename: James E
authors.initials: JE
authors.lastname: Pratley
authors.affiliation: Graham Centre for Agricultural Innovation, Charles Sturt University Wagga Wagga, NSW, Australia ; Faculty of Science, Charles Sturt University Wagga Wagga, NSW, Australia.
authors.forename: Min
authors.initials: M
authors.lastname: An
authors.affiliation: Graham Centre for Agricultural Innovation, Charles Sturt University Wagga Wagga, NSW, Australia ; New South Wales Department of Primary Industries Wagga Wagga, NSW, Australia.
authors.forename: David J
authors.initials: DJ
authors.lastname: Luckett
authors.affiliation: School of Agricultural and Wine Sciences, Faculty of Science, Charles Sturt University Wagga Wagga, NSW, Australia ; Graham Centre for Agricultural Innovation, Charles Sturt University Wagga Wagga, NSW, Australia.
authors.forename: Deirdre
authors.initials: D
authors.lastname: Lemerle
keywords: Brassica napus; LC-QTOF-MS and metabolomics; rapeseed; root exudates; weed