No abstract

A high-frequency protocol for induction of adventitious buds and plant regeneration from cotyledon explant of Jatropha curcas is described. The cotyledon explants of J. curcas cultured directly onto medium containing Thidiazuron (TDZ) induced regeneration of only poor quality adventitious buds that had a low regeneration frequency, and subsequently the elongation of shoot-buds was difficult and unsatisfactory. However, treating the cotyledon explants with high concentrations (10-60 mg/L) of TDZ solution for short time periods (10-60 min) helped to improve the regeneration frequency and enhance the quality of the regenerated shoot-buds significantly. The best shoot-buds induction (87.45%) and number of shoot-buds (11.23) per explant were seen when in vitro explants were treated with 20 mg/L TDZ solution for 40 min before being inoculated onto hormone-free Murashige and Skoog (MS) medium in 30 days. The elongated shoots initiated roots to become intact plantlets in rooting medium supplemented with 0.1 mg/L indole-3-butyric acid (IBA) effectively stimulated the initiation and growth of roots with the best rooting rate (44.28%). After acclimatization, these plantlets were transplanted to soil wherein normal growth was observed. Hence, an intact plantlet could usually often be gained at 60 to 70 days of culture by applying the culture method described in the present study. This protocol could be widely used for mass production of regenerative plants and the yield of transgenic plants through Agrobacterium-mediated transformation.

No abstract

Abstract. An effective protocol has been established to induce adventitious buds regeneration from 3 types of explants (petiole, petiolule, cotyledon petiole) of Jatropha curcas L. All the explants were dealt with high concentrations (5-120 mg/L) of TDZ solution for various soak time (5-80 min) with the regeneration frequency increased and the quality of the regenerated shoot-buds improved significantly compared with the traditional regeneration approach. The best result of adventitious buds regeneration was observed when explants were treated with 20 mg/L TDZ solution for 20 min before being placed on hormone-free MS medium for 30 days of culture. Moreover, addition of GA3 to the elongation medium was contributed to the prolongation of the shoot buds and the best elongate results could be gained at a concentration of 0.4 mg/L. By application of the new protocol described in this paper, plant regeneration efficiency of J. curcas was increased observably and the culture period was shortened in 65 days.

Abstract. In most Agrobacterium-mediated Jatropha curcas transformation systems, antibiotics are used for suppressing the growth of the bacteria. However, these antibiotics could also hinder largely the further growth of the resulted buds. To tackle this problem, grafting methods were tested by using J. curcas buds and shoots isolated from seedlings as scions and the lower part of J. curcas seedlings as stocks. It was found that the most suitable stocks were those prepared from five days old seedlings and had the upper part radical. In later experiments, significant enhancement on the growth of buds in culture was confirmed in 1/2 MS medium containing0.3 mg/l indole-3-butyric acid (IBA).With the help of above established grafting methods by grafting the buds to the stocks, the growth of the grafted buds could be effectively enhanced.

A new strategy of high concentration short duration treatment of Thidiazuron (TDZ) for enhancing adventitious buds formation from hypocotyl explants were attempted in Jatropha curcas. The best shoot buds induction (81.91%) and number of buds per explant (10.16) were obtained from hypocotyl explants treated with 20 mg/L TDZ solution for 20 min, followed by 30 days of culture on hormone-free MS medium. The elongated shoots initiated roots to become intact plantlets in rooting medium containing indole-3-butyric acid (IBA) and L-glutamine (Gln), and the results showed that the initiation and growth of roots were effectively stimulated with supplementing 16 mg/L Gln into the rooting medium, and having the best rooting rate (51.39%). After acclimatization, an intact plantlet could usually be gained at 60 days of culture by using the culture protocol described in this study.