Phenotypic Variation And Genomic Polymorphism In The First Generation From Alfalfa Seeds Mutagenized On Spaceship

The genetic diversity of Alfalfa Seeds mutagenized on Spaceship Which is"shenzhou 2"were analysed by using the SSR technique. The results were as follows:1.Establishment of SSR-PCR reaction system for Alfalfa: The orthogonal design was used to optimize SSR amplification system.Two orthogonal experiments were made to investigate the amplification efficiency of different amplification conditions. Results showed that the optimum concentrations of reactants in 25μl reaction mixture were as follows: dNTP0.2 mmol/L, Taq DNA polymerase 2U, Primers 0.7μmol/L, Mg2+ 2.5mmol/L, 10×buffer and 60ng template DNA.The reaction process went as following: the temperature profile used for PCR was 94℃for 3 minutes, followed by 35 cycles of 95℃for 1 minutes, 52℃for 1.5 minutes, 72℃for 1minute, and was terminated with a 8～minute DNA extension step at 72℃,then keep in 4℃.2. The selecting of SSR primers and amplification of PCR: There were 6 SSR primers by sieving which can produced DNA polymorphism in 17 SSR primers. In experimental materials,25 DNA bands were amplified,about 2 to 8 DNA bands were amplified by each primers, and the average of bands were 4.17.Combining the four kinds of character changes, to detect plants, Number and size of alleles and alleles frequencies and Polymorphism information content (PIC)which were choosed,PIC changes between 0.2216 to 0.8328, and the average is 0.6366. These results indicated that the genomic changes occurred.And more genomic loci changed might appear in some plants.3. The genetic diversity analysis based on the SSR mark bands and the summarized information:There are 56 plants(25% in total 224 SP1 plants) which have different mark bands with the contrasts.In the 56 plants,there are 13plants have 3 polymorphism allelic gene at least. There are DEFI-04,DEFI-07,DEFI-50,DERBY-15,DERBY-35,Algonguin-01,Algonguin-10,Algonguin-28,Algonguin-35,Algonguin-43,Algonguin-65,Sanditi-21,Sanditi-49.4. Prospect the breeding of the mutation plants: Using Molecule Marker Technology to analysis the first Generation Alfalfa Plants and further generations and selection of several mutants with promising agronomic traits,follow the source and traits of genetic polymorphism;Mapping the mutation plants which have the 4 main variation characters: Upper plants, High colour leavies, Biggish leavies, Lots leavies.For understand the mutagenic effects of space flight on Alfalfa seeds,as well as the genomic changes in consecutive generation plants developed from these seeds. The mutation in morphological traits and genomic polymorphism on plants developed from these seeds,as well as their selected progenies were vestigated in this study.