Establishment Of Somatic Embryogenesis Rapid Propagation System And Polyploidy Induction In Spathiphyllum Floribundum

Inflorescences and rhizomes of Spathiphyllum floribundum 'Mojo' were used as experimental materials.The effects of different hormones,hormone concentration,AgNO3 concentration and nutritional level on somatic embryogenesis and organogenesis regeneration were studied.In vitro somatic embryos and plants of Spathiphyllum floribundum 'Mojo' were induced by using oryzalin,trifluralin and colchicine with different concentrations and treatment duration,which provided reference for Spathiphyllum floribundum polyploid breeding and new varieties breeding.The results are as follows:(1)In Spathiphyllum floribundum 'Mojo',the best induction medium of inflorescences embryogenic callus was MS+ TDZ 5.0 mg·L-1+NAA 0.2 mg·L-1,induction rate as high as 64.97%.The best induction medium of rhizomes embryogenic callus was MS+2,4-D 4 mg·L-1+TDZ 0.5 mg·L-1,induction rate as high as 64.97%.The best induction medium of rhizomes organogenesis callus was MS+2,4-D 1mg·L-1+TDZ 0.5 mg·L-1,and the induction rate was 92.33%.Rhizomes were the best explant for embryonic callus induction.(2)The optimal medium for embryonic callus proliferation was added with 2 mg·L-1 AgNO3,the multiple was 3.08.(3)The best induction medium of somatic embryos was MS+6-BA I mg·L-1+TDZ 0.2 mg·L-1+NAA 0.2 mg·L-1,induction rate as high as 68.32%.The optimum nutritional level and hormone combination of somatic embryo germination was 1/2MS+TDZ 0.1 mg·L-1+IBA 1.0 mg·L-1,and the germination rate was 70.54%.The best culture medium of plant regeneration was MS+6-BA 0.8 mg·L-1 +IBA 0.2 mg·L-1,plantlet conversion rate as high as 89.34%.The optimum medium for rooting was MS+AC 1 g·L-1+NAA 0.2 mg·L-1.(4)The somatic embryos morphogenesis of Spathiphyllum floribundum is similar to the embryos morphogenesis of monocotyledon.It is mainly divided into following several stages:embryogenic cell,globular embryo,oval embryo,shield embryo,cotyledinous embryo,mature somatic embryo.(5)Optimization of chromosome sectioning on Spathiphyllum floribundum.The results showed that the optimal sampling time was 8:45-9:15 am and the optimal pretreatment was 0.002 mol·L-1 8-Hydroxyquinolin or 0.07 mmol·L-1 cycloheximidefor 4 h.Spathiphyllum floribundum is diploid and its chromosome number is 2n=2x=30.(6)In vitro somatic embryos and plants of Spathiphyllum floribundum 'Mojo' were used as experimental materials,which induced by colchicine,oryzalin and trifluralin with different concentrations and treatment duration.The best methods for tetraploid induced by somatic embryos were soaked 15d by 0.08%colchicine.The best way for tetraploid induced of vitro plants were soaked 5d by 100 mg·L-1 trifluralin.Tetraploid induced in vitro plants.Induction rate of vitro plants was higher than somatic embryos.It is easier for vitro plants to induce polyploid than somatic embryos.(7)Tetraploids of Spathiphyllum floribundum 'Mojo' were authenticated in morphology,chromosome number and stomata.Tetraploid plants grew better,and had wider and sicker leaf with dark green.The leaf index of tetraploid plants got smaller,leaf type was more symmetrical,and plant type was more compact.The chromosome number of Spathiphyllum floribundum 'Mojo'diploid is 2n=2x=30,and the Tetraploids is 2n=4x=60.The stomata size of Tetraploids is large and stomata destiny is smaller than diploid.