Study On The Rapid Propagation In Vitro Of Xanthoceras Sorbifolia Bunge

The regeneration system of asexuality for Xanthoceras sorbifolia Bunge’s rapid propagation was established by shoot organogenesis and somatic embryogenesis. And the total saponins of embryogenic callus by way of tissue culture and adventitious bud seedling were quantitative and qualitative determined by the method of UV-spectral. The main contents and results are listed as follows:1The plants were regenerated with bud explants.(1) The bud explants of Xanthoceras sobifolia Bunge cut from mother trees at different three times (May10th, Jun10th, Jul10th) were inoculated in medium. The sprouting and growth of buds obtained in May10th were best, and those in Jul10th were worst, almost no buds sprouting.(2) The optimal condition of sprouting and growth of buds inoculated in May10th was MS+6-BA0.1mg/L, and the rate of bud sprouting88.4%, the average height of shoot2.5cm. The optimal condition of sprouting and growth of buds inoculated in Jun10th was MS+6-BA0.5mg/L+NAA0.2mg/L, and the rate of bud sprouting51.3%, the average height of shoot1.5cm.(3) The subculture of shoot inoculated in May and Jun easily died, and its survival rate was24%at the better subculture condition of MS+6-BA0.5mg/L+NAA0.2mg/L after4weeks of subculture.(4) It was very difficult to root for the shoot obtained by the above. Its rooting rate was24%at the better culture condition of1/2MS+IBA0.8mg/L+NAA0.4mg/L.2The plants were regenerated with somatic embryo.(1) Embryogenic callus of Xanthoceras sobifolia Bunge were induced with mature zygotic embryos as explants. The induction rate was100%at the better culture condition of1/2MS+2,4-D0.3mg/L and the growth amount was better. The characteristics of embryogenic callus was well maintained at the better subculture condition of MS+2,4-D0.5mg/L, and its reproduction and growth were better.(2) The zygotic embryo explants of Xanthoceras sobifolia Bunge based on the3different development period (early, mid, and late) were inoculated in medium. The somatic embryo was better inducted in the development period of early and mid. And, the zygotic embryo of late was better to induce the adventitious bud.(3) The optimal condition of somatic embryo induction of zygotic embryo in the mid development period was MS+6-BA1.0mg/L+NAA0.5mg/L, and the rate of somatic embryo43%, the average number of somatic embryo63. There were constantly new somatic embryos forming during the subculture and proliferation, and the secondary embryos producing in the somatic embryo of initial formation. The somatic embryos could develop into mature cotyledon embryo, but also appear malformed embryos of morphological abnormalities. Mature somatic embryos could rapid germination in the germination medium of1/2MS and MS, and the germination rate reach to100%.(4) The optimal condition of adventitious buds induction of zygotic embryo in the last development period was MS+6-BA1.0mg/L+NAA0.5mg/L, and the rate of adventitious buds100%. The optimal condition of seedlings of adventitious bud formation was MS+6-BA0.2mg/L+NAA0.2mg/L with darkness. The emergence rate of seedlings was uniformity, and the average height was better, up to4cm. It was very difficult to root for the seedlings obtained by the above. Its rooting rate was24%at the better culture condition of1/2MS+IBA0.8mg/L+NAA0.4mg/L.3The preliminary exploration of the total saponin content of Xanthoceras sobifolia Bunge in somatic embryogenesis.The raw materials included the embryogenic callus induced by mature zygotic embryos, the adventitious bud seedling induced by immature zygotic embryos, and the husks of Xanthoceras sobifolia Bunge. UV-spectral method was used. Selecting ginsenoside-Re as control sample, colorating with perchloric acid, determining abso-rbability in the point of540nm by adopting spectrophotometric method. The linear relationship is good for ginsenoside-Re in scope of0.08-0.28mg (r=0.9995). The average recovery was96.97%and RSD was1.01%. This method is simple, accurate and sensitive with good reproducibility. The total saponin content of embryogenic callus of Xanthoceras sorbifolia Bunge embryogenic callus was the highest and0.9mg/g. Those in the adventitious bud seedling was the minimum and0.76mg/g. Those in the husks was0.86mg/g.