EFFICIENT INDUCTION, PROLIFERATION AND REGENERATION OF RUBBER TREE (HEVEA BRASILIENSIS MUELL. ARG) VIA SOMATIC EMBRYOGENESIS
H. Zhao1,2, R. Z. Jia2,Y. J. Zhu3, A. P. Guo2,H. C. Zeng1 and M. Peng2
1 Hainan University, Haikou, Hainan, 571101, China, 2 Institute of Tropical Bioscience and Biotechnology, Chinese Academy of TropicalAgricultural Sciences, Haikou, Hainan, 571101, China, 3 Hawaii Agriculture Research Center, P. O. Box 100, Kunia, Hawaii, 96759 USA
Corresponding author e-mail: mmpeng_2000@yahoo.com
ABSTRACT
An efficient protocol has been established to induce and proliferateembryogenic callus and regenerate plants using anther tissue culture of rubber tree (Heveabrasiliensis Muell. Arg), clone Reyan 7-33-97. The process of embryo-development from somatic embryos was divided into five stages: embryogenic callus, globular embryos, heart-shaped embryos, torpedo embryos and cotyledon embryos. Efficiency of proliferation and regeneration using embryonic tissues at different physiological stages was determined. A number of conclusions were reached. Friable embryogenic callus was the most suitable tissue for direct long-term proliferation by subsequent subcultures. The rates of proliferation and embryo development did not decrease after two years in tissue culture. Heart-shaped embryos and early embryogenic forms, including embryogenic callus and globular embryos, could proliferate on the media used in subculturing. After repeated proliferation, these tissues could be induced to form mature embryos in 1 - 3 months using MS2 embryogenic tissue induction media. Torpedo embryos and cotyledon embryos could not directly proliferate on MS3 media, but highly embryogenic calli could be induced from them using embryogenic callus induction media (MS4). The highly embryogenic calli could further be induced to form a large number of embryos on MS5 media to achieve an indirect but efficient proliferation. By selecting the same physiological stage of embryonic tissue from the material to be subcultured, the process of somatic embryo development could be controlled to ensure uniform development.
Keywords:Heveabrasiliensis, embryogenic tissue, somatic embryo, anther culture. |