variabilité morphologiques et conservation des morphotypes de jatropha curcas linn. (euphoriaceae) au benin.

This study is a contribution to Jatropha curcas cultivation and seeks to analyze the morphological variability and identification of morphotypes of Jatropha curcas. The study was conducted in 44 communities equitably distributed among 22 towns (populations) and geographically widespread in the 10 phytodistricts of Benin. Per population, at least 30 individuals of the species spaced at least 20 meters apart were randomly selected for the collection of morphological data. In total, 840 individuals, 714 leaves, 2294 fruits and 3465 seeds of Jatropha curcas were measured in all the country. The part of the variability of Jatropha curcas morphological traits due to individual, populations, phytodistricts, climatic zones were determined using the variance component analysis. The stepwise discriminant analysis was performed on Jatropha curcas populations to identify the morphological traits which discriminate them and the numeric classification was realized to regroup Jatropha curcas populations. The results show that variability of Jatropha curcas morphological traits is generally larger at individual level or between individuals of the same population than between populations, phytodistricts and climatic zones except fruits and seeds weight whose variability is larger between populations. Ten of twenty-one morphological traits studied were identified as the most discriminant variables of Jatropha curcas. Four morphological groups of Jatropha curcas were distinguished in Benin considering 10 discriminant variables. Keywords: morphological traits, variability, Jatropha curcas, Benin.