Study On The Way Of Inducing Haploid Through Gynogenesis Of Cucubita Pepo

To obtain haploid is the most important part of the process in haploid breeding programs. In this thesis,In vitro isolated culture of the unpollinated ovules of squash(Cucurbit pepo) through inducing embryoid was studied and the induction of haploid plants was achieved successfully.As a result of the present study,hapoid production was strongly influenced by genotype and the heat pretreatment had a positive effect on the inductivity.Through chromosome counting and chloroplast counting cytologically,the proportional relation between different ploidy of the regenerated plants and the range of variation of chloroplasts was revealed,so this method of chloroplast counting in guard cells was practical in squash was proved and the variation of data was offered as a reference for other breeding researchers .On this basis, To solve the problem about the origin of the haploid regenerated plant ,the embryogenesis process was revealed in the embryology level and confirmed the fact that the haploid regenerated plant came from the egg apparatus and that some haploid regenerated plants became diploid plants autogenously in the development process. So the feasibility of this inductive method was tested and verified.All the work will help to improve the inductivity of haploid regenerated plants.