Inheritance And Molecular Markers Of Sex Determining Genes And Their Application In Cucumber(Cucumis Sativus L.)

Cucumber is an important vegetable crop and sex determination in cucumber is as a model system for molecular biology. In this thesis, the inheritance and molecular markers of sex determining genes, polymorphisms of EIN3 and EIN3 RFLP-Bfm I enzyme digested reaction system associated with sex determination, the effects of different hormones on the sex expression were investigated in cucumber. 1 Inheritance of sex determining genes in cucumberThe sexual phenotypes of two crosses { gynoecious(WI1983G) and hermaphrodite(WI1983H), monoecious(95) and gynoecious(WI1983G)} and their F₁, F₂, BC1P1, BC₁P₂ were analyzed. The result indicated that m locus were considered to regulate bisexual flower expression and the partially dominant F locus were considered to regulate the degree of femaleness as prior research' s results.Through the analysis of the sexual character of monoecious plants based on the ability of producing exclusively female flowers at later stagers, monoecious cucumber could be divided into two groups of monoecious: common monoecious(without exclusively female flowers at later stager) and monoecious-subgynoecious (MOA-subgynoecious, with exclusively female flowers at later stager). In the experiment, which 5 inbred parents of 98-17(MOA-subgynoecious), S-2-98(MOA-subgynoecious), WI1983G(gynoecious ), WI1983H(hermaphrodite), 95(monoecious) and their F, Of 98-17 X 95,98-17 X WI1983H, S-2-98 × 95, S-2-98 × WI1983H, S-2-98 ×WI1983G and F₂, BC₁P₁, BC₁P₂ were as research materials, Genetic analysis had showed the two MOA-subgynoecious inbred lines with the ability of producing exclusively female flowers at later stager were controlled respectively by one pair of incompletely dominant gene and one pair of recessive gene, which were respectively designated presently as Mod-Fl and mod-F2. Mod-F1 and mod-F2 loci, which enhances the intensity of femaleness, inherited independently with F and M genes.1 Effect of different chemical treatments on sex expression of MOA-subgenoecious cucumber plants.