Brassica napus mutation population

The winter oilseed rape Brassica napus var Cabriolet from Monsanto was mutagenised using EMS to generate the population JBnCAB_E (The JIC Consortium Brassica napus CABRIOLET EMS).

~ 25,000 Brassica napus seeds of Cabriolet were mutagenised and ca. 6000 lines were developed from three EMS treatment levels (0.4%, 0.6% and 0.8%). These lines were grown on to create M2 DNA stock for mutation screening and M3 population seed.

 EMS induces G/C to A/T point mutations randomly throughout the genome. These may result in the substitution of amino acids, the alteration of gene splice sites or the introduction of premature stop codons, leading to a partial or complete loss of gene function or, less frequently, to alteration of normal gene function. Such mutations are important to research by allowing us to understand the role of specific amino acid residues in protein function and provide useful information for understanding the gene function or be used to generate breeding lines with desirable phenotypes by introducing novel alleles into the genepool which are not available in current breeding lines or wild germplasm.

Sequencing of a 700bp amplicon on ~900 lines identified the mutation rate to be between 1.3% (0.4% treatment level) and 4.9% (0.8% treatment level). Therefore for any given 500bp amplicon you could expect ~160 mutants within the population, with 75% of the G + C bases present within the genome having been mutated.

 

We have already screened half the population for mutations in a 700bp region of a homologue of our first gene of interest. This resulted in 49 confirmed amino acid substitution (non-silent) mutations and five loss of function (STOP) mutants. Selected mutants showing desirable phenotypes have been incorporated into our commercial partner's breeding programs.

JBnCAB_E is currently being utilised as part of the BBSRC Crop Improvement Research Club (CIRC) project on Exploring knowledge of gene function to combat pod shatter in oilseed rape in collaboration with Lars Østergaard, John Innes Centre.

The population is available for use on a collaborative basis, please contact Ian Bancroft.

JBnCAB_E was developed in collaboration with Cargill Plc., FUCHS Lubricants UK Plc., Home Growth Cereals Authority (HGCA), John Innes Centre, KWS UK Ltd., Monsanto UK Ltd., Saaten-Union Ltd. and Velcourt Ltd. It was sponsored by the BBSRC through the Renewable Materials LINK programme (LK0843) and by HGCA (RD-2007-3356).