In vitro rejuvenation of Hevea brasiliensis
Microcutting is a repeated process in which in vitro shoots develop new shoots from axillary meristems. In Hevea, this system works for seedlings, but not for shoots derived from mature trees. As for a lot of other tree species, one of the consequences of aging (losing juvenility) is poor in vitro growth and multiplication and the lack of a proper geotropic (tap)root system. In rubber tree, somatic embryogenesis on young inner seed integument explants provides a mean to regain complete juvenility of a rubber tree clone. This tissue is genetically identical to the mother plant. The relatively short embryogenesis procedure, from primary callus, minimizes the chance of somaclonal variation and mutations. It is not easy to convert the embryos into plants, but when this is accomplished, they can be multiplied in vitro by a suitable microcutting procedure. Socfinco, a plantation company owning large areas of rubber plantations in Africa and Asia, is funding this research. Hevea fruits containing immature seeds are sent from Ivory Coast to Ghent University in order to rejuvenate the mother plants. One year later, rejuvenated stocks plants are sent to Indonesia for industrial scale micropropagation by microcutting. They are also used for long-term field trials and establishing rejuvenated budwood gardens.
Ghorbani, S., Mignon, E. and Werbrouck, S.P.O. (2018). In vitro rejuvenation of Hevea brasiliensis. Acta Hortic. 1224, 191-194
somatic embryo, integument, yield, germination