Genetic Diversity Analysis of Physic nut (Jatropha curcas L.) Using Morpho - Agronomic Characters

The study was conducted to assess the intraspecific variation, interrelationships and distribution vis-à-vis, the phenotypic diversity of 13 Jatropha curcas accessions, using 21 quantitative traits, subjected to correlation analysis and two phenetic analysis methods (principal components analysis and cluster analysis). PCA reduced the collected data to 5 principal components that cumulatively explained 88.81% of total variance. PCA also subdivided the Jatropha provenances into distinct groups on the basis of height. The two clustering mechanisms Average Linkage (UPGMA) and Centroid Methods (UPGMC) divided the provenances into two major groups and revealed the divergence of Tubao- Philbio from the rest of the provenances. However, the study failed to adequately establish a relationship between spatial dispersal and genetic divergence in the Jatropha genotypes implying possible genetic homogeneity for the accessions studied. Possible causes to this are similarities in agro-climatic conditions, seed movement and the paucity of polymorphic morphometric markers. Screening for more quantitative traits and the use of more advanced molecular marker technologies are therefore recommended for a more accurate estimation of genetic diversity in Jatropha.