A cytogenetic analysis was performed using a chromosome splash technique in root cells of Tamarindus indica from seeds of wild and cultivated varieties individuals in Mexico. Cytological data in typical metaphase cells show a somatic diploid number of 2n = 2x = 24 which confirms previous counts although it is different respect to others registered in paleotropical regions and thus, the role of disploidy in the genus evolution is discussed. The karyotypic formula established here as 16m + 6sm + 2stsat and the chromosomal size obtained confirm that in Caesalpinioideae predominate symmetrical karyotypes and chromosomes of small size (< 3 μm). The constant association amongst satellites and single nucleolus in prometaphase confirm that subtelocentric chromosomes bear the nucleolar organizing region (NOR). Differences in total haploid chromosomal length between wild and cultivated material could indicate different geographic origins in the seeds now employed of cultivars in Mexico or evidence a process of intensive artificial selection on the fruit. It is necessary to evaluate the extension of numerical and morphological variation in more New World populations.
