Natural variation in fruit characteristics and seed germination of Jatropha curcas in Benin, West Africa

Abstract

An investigation was conducted in the ten phytodistricts of Benin, West Africa, in order to assess the level of morphological variation in Jatropha curcas seed and their germination potential. Hierarchical classification of the morphological traits of seeds identified five morphotypes, using 54% of the overall morphological information.Canonical discriminant analysis performed on the five morphotypes revealed highly significant differences. Morphotype 1 included seeds from the phytodistricts of Côtier, Pobè, The Ouémé Valley, and Plateau. Morphotype 2 and Morphotype 5 seeds were from the phytodistricts of Bassila, Zou, and Borgou-Sud; while Morphotype 3 and Morphotype 4 seeds were from the phytodistricts of Borgou-Nord, the Atacora Chain, and Mekrou-Pendjari. Significant morphological variation existed within the seeds as a consequence of genetic make-up and/or environmental effects. Seed from Mekrou-Pendjari and the Atacora Chain were black, smooth, light (0.67 g /seed), and small (1.76 cm-long and 1.15 cm-wide). Seed from Plateau, Côtier,The Ouémé Valley, and Pobè zones were brown, rough, heavy (0.84 g/ seed), and large (1.97cm-long, 1.2 cm-wide). All seed germination started 4 d after sowing and ended between day-7 and day-8. Seed germination timing varied significantly with morphotype.