The relationship between succulence and shoot biomass differences according to nutritional status in Jatropha curcas L.

Abstract

Diverse types of studies have examined the application of Jatropha curcas L. as a source of biofuel. Mineral nutrition levels modify the patterns of crops' growth and productivity, as well as the expression of morphophysiological traits of adaptive value. This study investigated the effects of nutrient solution concentration on biomass partition patterns and morphological attributes linked to water content in organs of J. curcas. Selected seedlings of accession 842 were cultivated in full experimental nutritive solution, and in solutions diluted to half concentration and a quarter concentration, all adjusted to pH 6.0. After 28 days under controlled conditions, plants were harvested and measured for height, leaf area and fresh and dry mass of leaves, petioles, stems, roots and total mass. From these data, specific leaf mass, leaf succulence and stem water content levels were calculated. The results indicated that according to increased nutritive solution concentration, plant shoots had up to a two-fold increase in height, and that a decrease in these concentrations caused drastic root and total dry mass reduction. At full concentration, there was a tendency towards dry mass allocation in roots. Comparatively, leaf traits were very sensitive to nutritional level without affecting leaf succulence. Contrastingly, relative to stems, these values significantly increased according to increased nutritive concentration. It could be concluded that beyond its productive importance, the nutritional level available to these plants exerts a positive influence on tissue water contents of succulent stems, whose ecophysiological importance demand additional studies. key words: Leaf area, relative concentration of nutritive solution, specific leaf dry mass, stem succulence.