Genetic Diversity in C Genome Diploid Brassicas

Diploid and allotetraploid Brassica species encompass a wide range of vegetable and oilseed crops that are grown around the world primarily for food, but increasingly also as a feedstock for biofuels. Improvement of these crops through breeding focuses on yield and quality, with the main priorities being resistance to a wide range of pests and pathogens, reducing the requirement for fertilisers, improved nutritional properties and adaptability to a changing climate. The C genome diploid Brassicas (one half of the AC genome of oilseed rape/swede) includes a highly polymorphic group of vegetables such as cauliflower, Calabrese, Brussels sprout, cabbage, kohl rabi and kale. In addition, there are a number of interfertile wild species relatives that potentially harbour a rich source of novel beneficial alleles. However, most breeding is restricted to crosses within a crop type due to the difficulty and time required to identify and introgress a novel trait. To address this we are developing Diversity Fixed Foundation Sets (DFFSs) which represent genetically fixed diversity core collections of the vegetable and wild species Brassicas. We have recently assessed the genetic diversity captured within these DFFSs using an extensive panel of SNP markers developed from advanced drafts of genome sequence data. We have also used Illumina sequencing to examine the leaf and root transcriptomes of these lines. Furthermore, we are screening these populations for a range of traits and will report on our progress to date.