Mapping populations to capture genetic diversity

New doubled haploid populations, generated by OREGIN (2008-2013)


The presence of novel beneficial alleles for many agronomic traits is very difficult to detect in non-adapted germplasm, such as most lines of the Bna DFFS. Complex traits, such as yield, stress tolerance and resource use efficiency, are controlled by many loci, but beneficial alleles not present in the breeders’ gene pool will typically be masked in such so-called “exotic” germplasm by the major negative impact of deleterious alleles at key loci (e.g. disease susceptibility, flowering time, fertility). To date, this has limited the exploration of exotic B. napus germplasm.
This is now being addressed in OREGIN through development of segregating populations derived from crosses between exotic lines (e.g. lines from the BnaDFFS) and a modern Winter oilseed rape line with good agronomy. Such populations need not be very large, as their purpose is primarily to reveal transgressive segregation and to provide lines for further crossing and genetic analysis to confirm utility via subsequent “pre-breeding” activities

The traits identified as those in most need of improvement that were not already being addressed by the private sector plant breeding community were:

The agreed design for generation of populations was to make five crosses from selected parents with potentially useful traits onto a single contrasting parent line (Temple) that has good agronomy (used as the female in all crosses to standardise cytoplasm).

Lines to be used for development of doubled haploid (DH) mapping populations

Accession Type Parent Trait Characters
Temple WOSR female Good agronomy high oil, NUE good vigour
Lesira WOSR male Pest resistance hairy leaves, seedling slug resistance
TN145* WOSR male Vigour high yield, low glucosinolate, link to TNDH
TN172* WOSR male Early vigour early vigour, link to TNDH
POSH MC169** WOSR male Seed loss pod shatter resistance, from mapping population
Canard Forage rape male Nutrient efficiency low % N, P, K in shoots, average vigour
* TNDH mapping population (Tapidor × Ningyou 7). Tapidor has high % N, P, K and low seedling vigour.
** Mapping population for pod shattering resistance (Apex × (N-O-109 × synthetic napus)). Poor agronomy


Timetable

The crosses and establishment of doubled haploid lines, and initial seed bulking is being carried out at Elsoms Seeds under the direction of Mark Nightingale.

Availability



This Page Was Last Edited: 12-Aug-2009