The objective of this study was to determine the genetic basis, the coefficient of kinship, and the genetic diversity of rice varieties released between 2003 and 2014, in thirteen member countries of the Latin America Fund for Irrigated Rice (FLAR). Pedigrees of o 51 rice varieties were analyzed at the International Center for Tropical Agriculture (CIAT), Palmira, Colombia between 2014-2015 The genetic variability of these varieties was represented by 120 ancestral or traditional cultivars (2.4 ancestral/variety); 33 of these contributed to the 83.9% of their genes, from which, three (ancestors with IR 8 origin), accounted for 35.6% of their genes. It was also shown that the coefficient of kinship (rxy) between different commercial varieties ranged from 0.03 (very unrelated), up to 0.99 (highly related). The average rxy of all 51 varieties was = 0.19. Regarding the varieties by country, the average rxy varied, the minimum was obtained by Ecuador 0.13 and the varieties from Venezuela obtained the maximum 0.31. The cluster analysis separated the genotypes in fourteen different groups based on highly related or very unrelated varieties. These results indicate that a broadening of the genetic base has been accomplished. 

Keywords: pedigrees, traditional cultivars, genetic diversity, parents, genes.