Construction of doubled haploid plants and flow detection of their ploidies in Brassica napus

Large and small seed lines of Brassica napus L.were used for microspore culture and haploid identification by flow cytometry method.The factors effected embryo production rate were investigated.It was found that the optimal bud material of 2.5 to 3.5mm grew at primary flowering period.The liquid medium added with 0.1mg/L 6-BA was able to accelerate the embryogenesis.Activated-carbon has no obvious promotion to the occurrence of embryo.The flow cytometry was found to be quick and accurate on ploidy detection.Results showed that after colchicine doubling,the proportion of doubled haploid(DH) plants were 49%.There were also a few of triploid(11.3%),tetraploid(1.1%),and chimera plants(27.3%).The present study offered new experience to obtain pure materials and to construct doubled haploid lines in B.napus breeding.