Characterization of adaptation of a spring Brassica napus doubled haploid population derived from a winter by spring cross

Genetic diversity available in the Western Canadian adapted Brassica napus germplasm has decreased substantially in recent years, leading plant breeders to search for new sources of diversity. This study aims to determine whether the relevant agronomic traits as well as increased sub-zero temperature tolerance can be combined within the context of a European winter-type by Australian spring-type Brassica napus doubled-haploid (DH) population containing 115 DH lines. The hypothesis is that DH individuals will be found that possess sub-zero temperature tolerance as well as early flowering and maturity. There are three major objectives in this research: 1) characterization of the agronomic traits of this population including flowering times and maturity using field experiments, 2) evaluation of sub-zero temperature tolerance using field experiments, and 3) evaluation of low temperature germination ability using laboratory experiments. Analysis of the agronomic, sub-zero temperature tolerance and germination data together suggests that, since there are examples in this particular population, it is possible to combine increased sub-zero temperature tolerance with early maturity in a spring-like growth habit. The combination of increased sub-zero temperature tolerance, lack of vernalization requirement and early maturity in an otherwise winter-type genetic background represents another step in germplasm development within Brassica napus.