Technical Research On Microspore Mutation With EMS In Brassica Napus

Ethl methane sulfonste(EMS) is a kind of alkylating agent which has remarkable mutagenesis effect in chromosome mutagenesis. It has been widely applied in auxiliary breeding and germplasm innovation. This experiment adopts three EMS concentrationsnamely 0.02%, 0.04% and 0.08% (v/v) and two treating durations which are 10 minutes and 20 minutes to treat on in vitro microspore of nine lines from five strains in Brassica napus ,that including 7679-1,7679-2,7680. Investigate the microspore's embryogenesis ,regenerative ability, and the microspore-derived plant's phenotypic and qualitive variation. The finding results are listed as follows:1. There are diffences in microspore embryogenesis of various genotypes, material7679 get embryo easily,the ability of embryogenesis can reach 100%. 2050-2 embryogenesis is very low, which produces 0-1.7 embryoes per alabastrum. Embryogenesis ability tends to be consistent in different lines of the same strain. For example the embryogenesis ability are all extremely low as 0-4.0% in fore lines of strain 2050.2. The influence of EMS concentration and treating duration on microspore-yield embryo number . when EMS concentration is same every material's embryo number are always reduced by prolong of treatment duration and the longer the time is the speed ofembryo generation descends slower..when treating duration is same 7679-2,7680'sembryo number reduced accelerative by increase EMS concentration, and the more the concentration is the speed of embryo generation descends faster..3. Every material has its own medial lethal concentration(LC5o): 7679-1 producing embryoes was about half of the CK when EMS concentration was 0.04% and the duration of EMS treatment was 10min; 7679-2 producing embryoes was about half of the CK when EMS concentration was 0.08% and the duration of EMS treatment was 10-20min;7680 producing embryoes was about half of the CK when EMS concentration was 0.04% and the duration of EMS treatment was 20min. 4. The phenotypic variation has get from DH plants' by EMS mutagenesis. Variation in economic character : height decreases, silique becomes shorter , branching number increases. Flower organ morphological variations including : pink petal, white peta; got more than six stamens, more than fore petalsl, and stigma exsertion. Qualitive variation:got a DH plant whose oil content achieved 43.81% (Donor adult plant index of oil 38.12-40.93%), a DH plant whose oleic acid content was 68.64% (Donor adult plant oleic acid content 62.93-65.82%).5. EMS treatment influence the chromosome double rate of microspore-derived plants. In 7679-2's regeneration group, CK chromosome double rate was 54.0% by treating with colchicines, regeneration groups which treated by EMS before colchicines treating that chromosome double rate were 50.0-92.4%, were mostly higher than CK. In 7680's regeneration group, CK chromosome double rate was 96.7% by treating with colchicines; regeneration group which treated by EMS before colchicines treating that chromosome double rate were 85.7-98.0%. In a certain amount of concentration, EMS mutagenesis treatment approved the double of regeneration plant chromosome.