Influence of various carbohydrates on the in vitro micropropagation of Nauclea diderrichii (De Wild &T. Durand) Merrill, an endangered forest species in Togo

Abstract

The over exploitation of Nauclea diderrichii, for its very resistant wood against the attacks of fungus (Coriolus versicolor), Lyctus, termites (Reticulitermes santonensis) and marine borers, leads to its disappearance in Togo. This forest species produces many fruits containing numerous seeds; unfortunately their seedling is laborious in its biotope. In vitro micropropagation trials were carried out for a faster and massive  regeneration. The effect of carbon source on the rooting and the growth of seedlings were studied in the presence of sucrose, glucose, fructose, mannitol, maltose, galactose, mannose, lactose, sorbose and sorbitol. Woody plant medium (WPM) of Lloyd and McCown has been used. This medium was modified by supply of microelements and vitamins of  Murashige and Skoog and supplemented by 30 g/L of these carbohydrates. The best plants’ growth and rooting were obtained with sucrose. Sucrose appears to be the most favorable sugar to ensure the in vitro  micropropagation of N. diderrichii. Sorbose caused the necrosis of explants in culture. The mannose and the mannitol, did not cause the necrosis of explants, but their presence had an unfavorable role on roots initiation and slow down the plants’ growth.

Key words: Sources of carbon, Nauclea diderrichii, in vitro   micropropagation, Togo.