Agro-morphological diversity of edible Kenyan Crotalaria accessions

Abstract

Food shortage is the insufficiency of food supply; whose greatest contributor is production shortfall. Sub-Saharan Africa is among the poorest regions in the world and is characterized by over-reliance on agriculture. Therefore, there is a need for diverse food sources in the region if food sustainability is to be achieved. The lack of information on the scope of diversity, nutritional and medicinal properties of edible Crotalaria species (rattle pods) limits the prospects of scaling-up their production and development of related pharmaceutical industries. This study aimed to determine the distribution and distinction of edible Crotalaria species in Kenya. Different regions of the country as well as the Genetic Resources Research Institute of Kenya were sampled in a purposive manner. The gathered seeds were established at the University of Embu and the plants were continually evaluated using 8 quantitative and 6 qualitative traits. Three edible species (C. brevidens Benth., C. ochroleuca G Don and C. trichotoma Bojer.) were identified and characterized. Factorial ANOVA revealed significant differences (p < 0.001 for all traits) in all the parameters assessed, and minimal diversity in qualitative traits. Pearson's correlation depicted weak to moderate positive and negative correlations in all traits except for leaf area and leaf width which were strongly positively correlated (r = 0.84, p < 0.0001). Principal Coordinate Analysis of the quantitative traits revealed that the first five PCs accounted for 92.9 % of the observed variation, with PC1 having a large positive association with leaf area (0.439), plant height (0.419) and leaf length (0.418), a phenomenon that suggested that this component primarily measures plant biomass. Based on agglomerative hierarchical grouping, the samples were clustered into 6 groups. All the qualitative traits under study except the pod shape were intermixed among the samples and did not reveal proper distinctions among the species under study. This study serves as a basis for identification of additional edible species, in an effort to enhance food security.