Studies on microspore culture technology and application in hybrid breeding of spring Brassica napus L.

Studies on microspore culture of double-low spring lines and their F1 hybrids of Brassica napus.indicate that the certain relevance exists between the developing stage of microspore and bud size,and more than 80% of the microspore is in the single nucleus later period to binuclear early time when the bud size is 2.5~3.5mm.The embryo can be obtained easily in this stage.Donor materials are more conducive to produce embryos when planted in the constant low temperature.Plantlet rates can be enhanced through low temperature(4 ℃)and 30 d treatment.The best agar content of media is 12 g/L.The restorers of Qingza No.6 and Qingza No.7 was obtained by microspore culture.