Somatic Embryogenesis Induction And Doubling Genome Of Ionopsis Utricularioides Regenerated Plant Leaf Blades

Ionopsis utricularioides,a perennial herb,belongs to the genus lonopsis in the family Orchidacea.It is an Oncidium related species.Because of the high ornamental value,Ionopsis utricularioides often cultivated as a potted plant,it can be used as good parents for the cultivation of orchids.We firstly studied the in vitro regeneration of lonopsis utricularioides by using peduncles as explants,then induced somatic embryos from test-tube seedlings’ leaf blades,finally,induced autotetraploid by treating the explants in colchicine solution.The main results are summarized as follows:(1)the best surface sterilization condition of lonopsis utricularioides pedicel explants is treating the explants in 0.1%HgCl2 for 10 min;The best Multiple Shoot Induction medium is Hyponex NO.1+6-BA3mg/L+NAA0.5mg/L;The best proliferation medium is Hyponex NO.1 +6-BA2mg/L+NAA0.5-1mg/L;The best rooting medium is Hyponex NO.1+NAA1.5mg/L+sucrose20g/L.(2)This experiment use the first 3-4 leaves as explants to induce somatic embryos.The best somatic embryos induction medium is Hyponex NO.1+TDZ2mg/L+NAA0.5-1.5 mg/L;The best somatic embryos proliferation medium is Hyponex NO.1+TDZ1mg/L+NAA0.5 mg/L.Through paraffin section and stereoscope,the observation indicates that,in the process of somatic embryogenesis,a single cell or a small number of cells formed the embryogenic cell aggregates,then through spherical somatic embryos,PLBs and other stages,develop into complete plants finally.(3)The best treating condition of doubling genome is 2d treatment using 200mg/L colchicine solution,then inoculate the explants on proliferation and differentiation medium.Through the identification of flow cytometry,comparison of stomatal characteristics,and plant morphology observation,amounts to 21 tetraploids were identified from the mutant plants.