Molecular diversity in Jatropha curcas (L.) genotypes assessed by RAPD Markers

Jatropha curcas is a multipurpose shrub and is considered to have originated in Latin America but presently grown throughout the arid, semi-arid tropical and subtropical regions of the world. Jatropha is easy to establish grows relatively quickly and is hardy. Being drought tolerant, it can be grown in eroded areas. Jatropha is desirable as a source for biofuels given that its seeds produce up to 40 percent oil, and the species in general is highly resistant to drought and pests. Processed oil from crushed mature seeds can be used in existing standard diesel engines, while the residue can also be processed into biomass to power electricity plants. Despite these characteristics, the full potential of Jatropha is far from being realized. Very little information is available on genetic diversity among Jatropha curcas genotypes. So the major objective of the present study is to assess the genetic diversity among twenty genotypes of Jatropha curcas using RAPD markers. Twenty highly polymorphic RAPD primers were used in the present study. The twenty random primers showed a total of 158 reproducible bands. The individual primer produced bands in a range of four (LC-77, LC-84, and LC-96) to 22 (LC-89) bands with an average of 7.9 bands per primer. The polymorphism per centage was 100 percent for every primer. Five primers gave a total of sixteen unique bands. PIC values ranged from 0.09 for primer LC-77 and LC-84 to as high as 0.81 for primer LC-87, with an average of 0.43. The average expected gene diversity ranged from 0.20 for primer LC-89 to a maximum of 0.47 for primer LC-93 with an average of 0.36. The values of the similarity coefficients ranged from 3.3% between genotype 2 and 4 to a maximum of 93.7% between genotype 7 and 8. The dendrogram showed clear distinction among twenty genotypes by dividing the genotypes into seven clusters at 75percent similarity.