Abstract

Because of importance of winter survival in winter type of Brassica napus, this study was performed to identify the QTLs controlling winter survival and related traits using SSR and RAPD markers. For this, an F_2:3 population of 200 families derived from crossing between cv. ‘SLMO46’ (winter type and cold resistant) and cv. ‘Quantum’ (spring type and susceptible to low temperature) were used. Winter survival (WS), leaves per plant in rosette stage (L/P), crown wet weight (CWW), crown dry weight (CDW) and crown water content (CWC) were measured in F₃ families. 350 SSR primer pairs and 250 RAPD primers were used to assess the parental polymorphism. The 32 SSR primer pairs and 47 RAPD polymorphic markers between parental lines were used to screen F₂ individuals. Linkage map was constructed using polymorphic markers. The markers were assigned into 14 linkage groups with total length of 1199.1 cM and an average distance of 17.13 cM between adjacent markers. The relationship between measured traits and genotypic data was analyzed using CIM method and totally 12 putative QTLs were detected for studied traits. The explained phenotypic variance by identified QTLs ranged between 0.5 and 11%. The identified QTLs had positive and negative additive effects and transferred from both parents to F₂plants and F₃ families. Some of these QTLs located in the same genomic regions.

Key word: Brassica napus, molecular markers, QTL, rapeseed and winter survival.