Agricultural selection and presence-absence variation in spring-type canola germplasm

Annaliese S. Mason, Pratibha Chauhan, Shashi Banga, Surinder S. Banga, Phil Salisbury, Martin J. Barbetti, Jacqueline Batley

Research output: Chapter in Book/Conference paperConference paperpeer-review

11 Citations (Scopus)
349 Downloads (Pure)


Brassica napus (rapeseed, canola) is an important oilseed crop worldwide as well as a recent agricultural hybrid species, resulting from crosses between progenitor B. rapa (turnip) and B. oleracea (cabbage) species in the last few thousand years. No wild form of B. napus is known to exist, making B. napus an interesting model for studies of genetic and genomic evolution in a polyploid under agricultural selective pressure. We generated genotype (Illumina Infinium 60K Brassica array) and phenotype data for elite spring-type B. napus lines from Australia, China and India (only one line). Phenotypically, plant growth, silique development and flowering traits were more likely to differentiate Chinese germplasm, whereas resistance to blackleg disease, secondary branching and seed traits were more likely to differentiate Australian germplasm. Genetic differentiation between the Australian and Chinese populations was low (FST≤0.035). Genetic relationship was not a predictor of similarity in yield traits between lines. Presence-absence variants were detected across the population: variants shared by at least three lines were present in every chromosome in the B. napus genome, and large missing chromosome segments (>1Mbp) putatively due to A-C genome translocations were observed on chromosomes A7, A10, C1, C2, C6, C8 and C9. Our results highlight that widespread presence-absence variation is usual in B. napus, and may suggest that phenotypic and genetic diversity are not closely linked within spring-type B. napus from Australia and China, although the low sample numbers in our study prevent strong conclusions. We propose that inbreeding and low levels of genetic diversity, coupled with exchanges between the A and C genomes, were major driving forces behind genome evolution in this recent agricultural crop species.

Original languageEnglish
Title of host publicationCrop & Pasture Science
Subtitle of host publication2016 International Brassica Conference
EditorsAngela Van de Wouw, Jacqueline Batley
Place of PublicationAustralia
PublisherCSIRO Publishing
Number of pages10
Publication statusPublished - 1 Jan 2018
EventBrassica 2016 - Melbourne, Australia
Duration: 3 Oct 20166 Oct 2016

Publication series

NameCrop and Pasture Science
PublisherCSIRO Publishing
ISSN (Print)1836-0947


ConferenceBrassica 2016


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