Abstract:

In order to optimize the plant regeneration system of inner integument and promote the development of secondary somatic embryogenesis and transgenetic research of Hevea brasiliensis. Callus induction and somatic embryogenesis were conducted on different factors by taking inner integument of immature fruits from two clones Reyan 7-33-97 and Reyan 88-13 of Hevea brasiliensis. Calla induction were obtained on MH medium supplemented with 80 g/L sugar, 50 mg/L coconut water, 5.0 mg/L silver nitrate, 2.3 g/L phytagel and different concentrations of 2,4-D. The results showed that calla could not be inducted from two clones when the media had no 2,4-D. The induction rate of callus was gradually improved with the increasing of 2,4-D concentration. The rate was the highest, while the concentration reached 4.0 mg/L, respectively 88.28% and 86.67%. When the concentration of 2,4-D reached 6.0 mg/L, the rate was gradually declining. After the induction of callus, callus was transferred to modified MS medium supplemented with different concentrations of NAA. The results indicated that the embryoids of cotyledonary, cup-like, trumpet-like and leafy were easily produced with the concentration of 0.2 mg/L NAA from the inner integument of Reyan 7-33-97. The induction rate of cotyledonary embryoid reached only 4.00%. Somatic embryo was not beneficial to be produced when the concentration of NAA was lower or more than 0.2 mg/L.