In vitro germination and shoot proliferation of the threatened species Cinchona officinalis L (Rubiaceae).

Abstract

Cinchona officinalis is a forest product and endemic species of the Loja Valley in the southern region of Ecuador. Because of over-exploitation in the nineteenth century and current modification of its ecosystem, C. officinalis populations are threatened. Currently the natural regeneration of the populations is low, despite the fact that its plant regeneration capacity and seed formation are high. An efficient protocol for germination, shoot proliferation and plantlets regeneration was developed for this species. Phenolic compounds content and germination rate of C. officinalis seeds were compared with a control species, C. pubescens. Nodal segments from seedlings of C. officinalis were cultured on Gamborg (1968) medium supplemented with different combinations of plant growth regulators. Results suggest that the phenols compounds content is high in C. officinalis and should be removed with hydrogen peroxide or water washes to stimulate germination. Shoots and callus developed in a period of 45 days in nodal segments in most of plant growth regulators combinations tested. The highest shoot proliferation, callus formation and adventitious bud presence rates were obtained in medium supplemented with 5.0 mg l-1 6-benzyl-aminopurine and 3.0 mg l-1 indole-3-butyric acid.