The Study Of The Embryo Sac’s Development Characteristics And Ovule Tissue Culture Of Platcodon Grandiflourum

Taking unfertilized ovules of platycodon grandiflorum as materials,study of correlation characteristics between the embryo sac development stages and the bud length by adopting the technology of paraffin section, aim to provide theoretical basis for platycodon grandiflorum embryology research and the haploid culture, the results showed that:(1) The development of embryo sacs of platycodon grandiflorum belonged to polygonum type.(2) The embryo sac development stages is different at different lengths of bud;The embryo sac development stages is also different at the upper, middle and lower of a ovary in the same flower buds, the middle is faster than the upper and the lower.(3) When the length of Bud is betweenl.4 cm and 1.7 cm, more of the central ovule is in the stages of mononuclear embryo sac, suitable to ovule culture for the purpose to obtain haploid.To selectting the induction medium and differentiation which is suitable for ovule culture, taking unfertilized ovules of platycodon grandiflorum as materials, add different types and concentrations of hormone to the N6 mediun that as the basic culture medium, the results show that:(4) According to the callus induction rate and the size of the callus fresh weight, it is concluded that ideal induction medium is N6+1.0 mg/L 2,4-D+0.1 mg/L KT and N6+0.5 mg/L NAA+0.1 mg/L KT.(5) The induced medium which add 2,4-d and KT is advantageous to the callus induction of platycodon grandiflorum and its differentiation rate is also high.(6) When the concentration of 6-BA is 1.0 mg/L, combine with different concentrations of 2,4-D, NAA, IAA, while 6-BA combined with different concentrations of NAA, with the concentration of NAA increased differentiation rate show downward trend, but compared with other two kinds of auxin, its differentiation effect is best.however, when combined with different concentrations of 2,4-D, differentiation rate is the worst.(7) When the concentration of NAA is 0.5 mg/L,combined with different concentrations of 6-BA, when concentrations of 6-BA is 0.25 mg/L, differentiation rate is the highest, it is 88.3%.(8) Within the scope of this research, the best in the induction medium is N6+ 1.0 mg/L 2,4-d+0.1 mg/L KT,the induction rate is 100.0%ï¼›The best medium of the differentiation is N6+0.5 mg/L NAA+0.25 mg/L 6-BA,it was 88.3%.