The SRAP Molecure Marker Of F Gene In Cucumber

Cucumber (Cucumis sativus L.) originated from the northern part of India ,South of the Hymalays. It was cultivated all over the world and spread to China from middle Asia^[6]. Cucumber is a kind of annual climber plant that likes to grow in warm condition. The cucumber offers the food with the young and tender fruit; it is nutritious^[5]. With the development of protected horticulture , the demand for the variety of all female cucumbers increases day by day. The principle and method of the commonly used genetic breeding of plant have already lost the advantage in improving the properties of cucumbers. Namely estimating the breeding value through phenotype value for a long time, makes the heredity of the properties develop smaller and smaller, sex differentiation is the important stage of the ontogeny of a plant. The clarify of its differentiation mechanism has not only the theoretic meanings but have extremely important practice value in the development biology[10]. The date of the appearance and distributing state of female flower that is the sexual shows has tight relations with the ripe date, productivities and quality etc. Because of the difference of the variety and category, the sexual representations have remarkable diversity at the same time are subjected to the predominate of the changeable inheritance for the environmental change. So, under the situation that the culture form has already highly differentiated in so different seasons, controlling behavior has important meanings. The genetic mark, especially the technology of the protenic and biological markers play a more and more important role in announcing the research of mechanism of the sexcual differentiation in plant^[3]. Pure female breed of cucumber has important role in simplifying the hybridization breeding, decreasing the cost of produce the seeds and increasing the productivities. F gene is partly dominante, controls the female development, will accelerate the acquisition of allfemale strains with the auxiliary breeding of molecule mark of all female chains. Because resources while planting are limited, it will be an effective means to recombinate the useful gene of far reason in the variety of cucumber will be improved in the future to utilize genetic engineering. Carry on research to the cucumber gene, can lay the foundation for the further molecule breeding.1. Genetic analysis of cucumber sex differentiationThe Fl generation is obtained by hybridizing genotype FFMMAA pure female parent and genotype ffMMaa pure male parent then Fl selfcrossing produces the F2 generation and planting F2 generation produces 225 individual plants. According to the proportion of female and male flowers amount in 25 nodes of every plant, the strong male plant is the proportion less than 10%, the proportion more than 1000% is the strong female plantpure female plant haven't male flowers in 25 nodes, pure male plant haven't female flowers, the rest are polygamy. The amount of strong female plants are 28, pure female plants are 28,strong male plants are 56, pure male plants are 4, polygamy plants are 109.Strong female plant and pure fenale plant are called female plant;strong male plant and pure male plant are called male plant. The proportion of the amount of female plants, polygamy plants and male plants is close to 1 ∶ 2 ∶ 1.2. Extraction of F2 generation of cucumber genomic DNAThe single plant genomic DNA extracted by the improved CTAB method[71] and dissolved with TE.1% agar gel electrophoresis showed that genomic DNA size is 23kb around and the degree of purity could fits for the following experiments.3. Construction of DNA poolsAccording to concentration of DNA of the all female plants and all male plants,the female DNA pool is obtained by mixing the DNA of 12 all female individual plants and 1 weak female individual plants, the male DNA pool is gained by the mixing the 4 pure male and 4 strong male individual plants.4. Data statistic and analysis of SRAP molecular markerUsing 62 pairs of SRAP primer amplified female genomic DNA pool and male genomic DNA pool respectively, 1% agar gel electrophoresis showed that the band is a more broad or much more thicker bands, which explain that the two DNA pools have high Polymorphism, accord with the request of 4% denaturing polyacrylamide gels electrophoresis. After denaturing polyacrylamide gels...