Blackleg Resistance Gene Identification in Brassica napus: A Pan Genome Approach

The identification of genes underlying important traits is extremely challenging in complex genomes such as Brassica napus (canola/oilseed rape). However, recent advances in next generation sequencing enable much quicker identification of candidate genes for traits of interest, including through a pan genome approach. These include skim based genotyping by sequencing (GBS), gene loss and presence-absence variation (PAV) analysis. Here we demonstrate the utility of these tools for the identification of candidate disease resistance genes from B. napus for its most devastating fungal pathogen, Leptosphaeria maculans (blackleg). Analysis of the complete genome sequence of B. napus identified candidate CC-NBS-LRR and TIR-NBS-LRR family genes implicated in disease response, several of which were clustered around a region syntenic with major loci for blackleg resistance.  Molecular analyses of these candidate genes using skim-GBS in diverse cultivars and segregating populations, along with initial validation, will be presented.