Studies On The Tissue Culture And Plant Regeneration System Of Philodendron Gloriosum

A systematic research was carried out using stem segments and leaves as explants in order to develop an efficient tissue culture and plant regeneration system of Philodendron gloriosum. The affecting factors were analyzed and discussed, including plant growth regulators,basic media,carbon sources and season for isolating explants. The results were as follows.(1) The best way of explant sterilization was 0.1%HgCl2 for 9 minutes.(2) The best season for isolating explants was spring, especially in April; isolating explants during this season resulted in highest explant germination rate and lowest browning rate and contamination rate.(3) The basic medium had significant effect on bud induction from stem segments; the suitable medium was MS for the bud induction.(4) The carbon source had significant effect on bud induction from stem segments, and sucrose was the most suitable carbon source for the bud induction, followed by glucose, while the effect of maltose was relatively poor.(5) Dark culture had no significant effect on the callus induction from the leaf.(6) The concentrations of 6-BA and the kinds of auxin had extremely significant effect on bud induction from stem segments, and the concentrations of auxin had no significant effect on bud induction from stem segments. The suitable concentration of 6-BA for bud induction was 3.0 mg/L, the suitable auxin was NAA, and the suitable concentration of auxin was 0.05-0.2 mg/L, the medium MS+6-BA3.0 mg/L+NAA0.1 mg/L was suitable for the bud induction, resulting in 88.86% of bud induction rate. (7) MS+6-BA1.0mg/L+NAA0.5mg/L+2,4-D0.05 mg/L was suitable for the callus induction. Satisfactory shoot regeneration was obtained using media MS+KT3.0mg/L+NAA0.2mg/L and MS+KT2.0mg/L+NAA0.1mg/L(8) The kinds of cytokinin and their concentrations had extremely significant effect on the multiplication rate of buds. Of BA, KT and TDZ, BA was the most suitable for the multiplication of buds and its suitable concentration was 4.0 mg/L. The concentration of NAA had significant effect on the multiplication rate of buds, and the suitable concentration was 0.2 mg/L. The medium MS+4.0 mg/L 6-BA+0.2 mg/L NAA was suitable for the multiplication of buds.(9) AgNO3 could stimulate plant regeneration, the suitable concentration for multiplication of buds was 3.0 mg/L. resulting in a bud multiplication rate of 2.10. GA3 restrained plant regeneration; with the increase in GA3 concentration, the proliferation of effective buds became poor, and the buds were of poor quality and were not desirable in subculture.(10) The kinds of auxin had extremely significant effect on plantlet culture, and its concentration had significant effect, whereas the concentration of BA had no significant effect on plantlet culture. The medium MS+6-BA1.5 mg/L+NAA0.5 mg/L was suitable for the growth of plantlets;and the medium MS+6-BA1.5 mg/L+ IBA0.5 mg/L was suitable for occurrence of new leaves of plantlets.(11) Roots could be easily induced, but the quality of the resultant roots on different media was obviously different; considering rooting rate, root number and root quality,the optimal rooting medium was 1/2MS+NAA0.1 mg/L+IBA0.2 mg/L+ AC0.1%, resulting in rooting rate of 100% and an average root number of 7.33.(12) The transplant medium in perlite, vermiculite and sands by 1:1:2 was optimal, in which the rate of survival was 92.5%.