Microspore culture of Brassica napus was carried out in this research, and several factors that affected microspore embryogenesis and plantlet regeneration of embryoids were explored and improved. One double haploid population derived from (zhongshuang 4R DH×P28) F1 was constructed successfully. Utilizing antifreezing identifying method identified the Fl DH population and selected stronger antifreezing lines in field.Genetic variations of the F1 DH population was analysed by AFLP in laboratory, and s...