| Psammosilene tunicoides belongs to genus of Psammosilene, Caryophyllaceae family. The dry roots of Psammosilene tunicoides has long been used as folk herbs in pain-relieving, anti-inflammatory, blood-stopping, immune-adjustment, and clinically used as medicine to cure rheumatoid arthritis and so on. Due to long term of growth, increasing demand of medicinal market, and destruction of environment, the amount of wild resource of P. tunicoides drastically declined recently, and consequently, the development of pharmacy enterprise and people’s usage safety of medicine were affected seriously. Since, propagation of P. tunicoides through biotechnology would be an efficient method to solve the crisis of medicinal material.Polyploid plants are always characteristic of huge phenotype, enhanced stress resistance, high accumulation of some chemical components and so on. In this study, the induction of polyploidy of P. tunicoides hairy roots by colchicine was carried out, and meanwhile, the growth and accumulation of secondary metabolites of the hairy roots-derived polyploid were both investigated. At the same time, in this paper, we studied the plantlets regeneration from the hairy roots and polyploid at various combinations of phytohormones, and it’s expected to lay foundation for getting P. tunicoides plants with excellent traits.The main findings are as follows:1. Determination of treatment time and concentration by colchicines. The effect of colchicine on the induction of polyploid from P. tunicoides hairy roots was of time-and concentration-dependent mode. At the settled colchicine concentration, the longer the treatment time was, the lower the survival rate of hairy roots would be; similarly, at the settled treatment time, the higher the colchicine concentration was, the lower the survival rate of hairy roots would be. Considered generally, treatment with 0.05% colchicine for 24 h was examined to be the best for hairy roots with a peak survival rate of 60%.2. Hairy roots-originated polyploidy was obtained by treatment of different concentrations of colchicines for 24 hours. Heavy branching of hairy roots-derived polyploid was observed, and also was concomitant with dense lateral root hairs. The growth rate of colchicines-treated hairy roots is generally faster than the ordinary hairy roots, but no difference in saponin content was found. The final dry weight of hairy root treated by 0.05% colchicines for 24 h was 1.5 times that of ordinary hairy roots, and 1.39% for saponin content.3. After induction of callus from hairy roots, the regeneration of plantlets from callus was then carried out. The optimal medium for induction of callus from P.tunicoides hairy root was MS + 0.5 mg/L 6-BA + 0.5 mg/L 2.4-D; and MS + 3.0 mg/L 6-BA + 0.2 mg/L NAA + 0.5 mg/L 2.4-D was the optimized formula for plant regeneration from callus.4. Compared to ordinary Psammosilene tunicoides plants, the regenerated plants of hairy roots have some features of smaller leaf length, shorter whole plant, and longer and stronger roots. The regenerated plants of hairy root-derived polyploid are stronger than ordinary plants with heavily branched roots, deep green leaves and stems, and dwarfed height, and slightly low content of saponin. |
