Studies On Breeding Spring-planted Brassica Napus Polima Cms Restorers By Microspire Culture

The microspire culture of spring-planted Brassica napus was investigated using some materials and their F1 hybrials growing under natural conditions in Xining during 2005 to 2006. The results showed as follows:1,Different genotypes of Brassica napus showed remarkable difference in ability of embryoids yields,and difference in plantlet rate.In all of the 8 materials,7 genotypes produced embryoids in 2005.In all of the 22 donor materials, 21of them being obtatined embryoids in 2006,the ration fo embryoids is among 0 to 36.94. ,verage embryoids per bud of 40.91% and 31.82% of which were over 5 and 10, respectively. The ratio of plantlet is among 2.07% to 24.5% in 2005 and 0% to 23.46% in 2006.2,The ratio of embryoids of most F1 hybrials and the teminal raceme were higher than their parents'and primary branches'respectively. The seeding period was delayed could make the ratio of embryos lower .The ratio of plantlet could be increased dramastidy after embryo were treated in low temperature,and the more time pretreated the higher plantlet ratio. We have found two materials,such as 1465(R)×2006 and 1759(R)×2239 which treated in low temperature for 80d ,the plantled rate is to 46.67% and 57.89% respectively. In the treatment of 0.6g/L colchicines for 5.0h and3.4g/L colchicines for 1.5h,the efficiencies of survival and doubling were the highest .There were fertile plants and semi-fertile plants after doubling, the pollen vigor of the former was higher than the latter's,furthermore ,the Selfing Seed-set Index of the former was high ,too.And the Selfing Seed-set.Index of 50% Semi-fertile plants was lower than 1.3,Quality analysis of DH ,we have found, the erucic aid of the 39 materials was lower than 1%,and 29 materials was lower than Qingza2.The glucosinolates of 18 materials was lower than 30umol/g,9 was lower than 25umol/g,1 was lower than 20umol/g,and 13 was lower than Qingza2.4,The 31 crosses were created by using the cross between 3 sterility (1289,2168,2235) and 11 DH(E-2,E-3,E-4,E-5,E-6,E-10,E-12,E-14,E-15,E-16,E-17), there were 14 crosses which fertile plantlet rate is 100%.5,The F₁ hybrids were creatded by crossing between 3 sterility and 10 DH which abtained by microspore culture.The position of F₁ hybrids seed yield is 1289×E-10>2235×E-10>2235×E-15>1289×E-3>2235×E-5.The general combining ability of E-10,E-15,E-3,E-5 was higher ,and the special combining ability in crosses is higher too ,furthermore ,the degree of fertile plantlet and the ratio of fertile plantlet were also higher .It was proved that the fine restorers can be bred by microspore culture.