Joint analysis for oil content and TRAP markers in elite castor bean strains
The demand for quality vegetable oil, such as castor oil, has been increasing significantly due to its great applicability in the cosmetic and industrial sector, especially with the advent of biodiesel. Castor bean produces a non-edible oil, with unique chemical properties, which makes it potentially useful for the production of cosmetics, aircraft lubricants and biodiesel. Breeding programs aimed at increasing the oil content in castor bean seeds are of paramount importance to meet the requirements of this market. In view of the above, we examined the genetic variability of elite castor bean strains through joint analysis of the oil content trait and TRAP (Target Region Amplification Polymorphism) molecular markers. This analysis was performed using the means for seed oil content of 40 elite castor bean strains, developed by the breeding program of the Genetic Improvement and Biotechnology Unit of the Federal University of Recôncavo da Bahia, together with genotyping of this population by means of 44 combinations of TRAP primers (fixed and arbitrary primers). Genetic dissimilarity between the strains was calculated through the Gower dissimilarity index, using the UPGMA clustering method. The means for oil content rangeed from 39.10 (UFRB 36) to 55.39% (UFRB 209), demonstrating that there is genetic variability among the strains. The 44 TRAP combinations enabled the identification of 380 fragments, 61% of which were polymorphic. The joint analysis formed three clusters, showing that there is genetic divergence among these elite strains. Therefore, joint analysis of the seed oil content trait and TRAP markers is efficient to evaluate the genetic dissimilarity in castor bean strains, demonstrating potential for the breeding program of the species.