Variability of ricin content in mature seeds of castor bean.

The objective of this work was to evaluate ricin concentration in castor bean seeds (Ricinus communis) of 20 accessions from the Banco de Germoplasma de Mamoneira of the Embrapa Algodao, Campina Grande, PB, Brazil, using the Enzyme Linked Immunosorbent Assay. Significant differences were observed among accessions. BRA 3271 had the highest ricin concentration in seeds (32.18 ng µg-1), and BRS Paraguacu had the lowest (3.53 ng µg-1). There is the possibility of selecting genotypes with different ricin concentrations, which can be used according on the interest of the breeding programs.