Morphological and molecular characterization of Jatropha curcas L. germplasm in Botswana

Jatropha curcas L. is an undomesticated plant species that has recently received great attention for its utilization in biofuel production in many countries including Botswana. The experiment investigated 30 J. curcas accessions, and the results revealed high significant differences (P<0.01) among accessions for peduncle length, number of seed per fruit, length of fruit stalk, fruit length, fruit width, seed length, seed width, seed weight, leaf length, leaf width, petiole length, total flower per cluster, female and male flower per cluster, and number of fruit per cluster. The qualitative characters revealed substantial amount of variability among the accessions except in fruit shape, stem color and flower color. Multivariate cluster analysis based on morphological characters and molecular characterization grouped the accessions into four clusters at dissimilarity coefficient of 1.37 and 0.85, respectively. The clustering based on morphological characters slightly matched that of groupings derived through molecular analysis with group A and B having some similar accessions. One Ghana accession used as reference was clearly separated from other accessions by both morphological and molecular markers, and also by seed weight and inflorescence compactness. Eight morphological characters and six molecular markers correlated positively with correlation coefficient values ranging from 0.56 to 0.66.   Key words: Characterization, genetic diversity, Jatropha curcas, molecular markers, morphological markers