Mapping of cold resistance genes in rapeseed (Brassica napus L.) using microsatellite markers

Microsattalite markers are genome specific, co-dominant and highly polymorphic markers with known map location. These markers are very suitable for quantitative trait loci mapping. In order to identify the molecular markers linked to cold resistance genes in rapeseed, a F2:3 derived population from crossing between cv. SLMO46 (winter type and cold resistant) and cv. Quantum (spring type and susceptible to low temperature) were evaluated using microsatellite markers. The LT50 (the temperature in which 50 % of plants are killed), as a cold resistance index in F3 families was measured. The parental polymorphism was assessed using 350 SSR primer pairs. The 32 polymorphic primer pairs were selected for genotyping of F2 individuals. Linkage map was constructed using polymorphic markers. The markers were assigned to five linkage groups. The relationship between LT50 and genotypic data was analysed using single marker analysis, interval mapping and composite interval mapping methods. Three detected QTLs explained 13 % of the LT50 phenotypic variations