DATA TO THE NON-STRUCTURAL CARBOHYDRATES OF THE FRUCTAN ACCUMULATING SPHAGNUM SPECIES FROM THE TROPICAL RÉUNION ISLAND IN RELATION TO THEIR ALTITUDE ZONE AND DISTRIBUTION

Abstract

The prevalence of fructan-producing plants is primarily restricted to the temperate climate, while they are virtually absent from the tropical regions. Although the Sphagnum genus has a worldwide distribution and considerable ecological importance, it is relatively rare for the whole of tropical Africa. The island of Réunion is located in the tropical climate and has a rich Sphagnum flora containing 14 species. Sphagnum species - as an exception amongst mosses - synthesise fructan and have a considerable amount of sucrose as well. No data on fructan content of Sphagnum occuring in tropical habitats have been reported so far. This short paper provided data first, based on experimental results, on the non-structural carbohydrate pool, especially fructans in Sphagnum species from a tropical region, from Réunion Island. Fructans accounted for 2-4% of the total soluble carbohydrates in the examined Sphagnum species. We compared the fructan content of eight Sphagnum species collected from Réunion in relation to their altitude zone and their distribution. The species generally increased their fructan accumulation as the altitude increased. Our preliminary experimental results show that fructans as an alternative storage carbohydrate to starch may play a role in the ecological niche preference of the Sphagnum species according to altitudinal zones.