Seventy eight black pepper clones (Piper nigrum L.) were analyzed by means of isozyme electrophoresis for the systems ACP, GOT, SKDH, ACO, G6PDH, PGI, 6PGDH and FUM, in order to evaluate the diversity through the percentage of polymorphic loci, mean number of alleles per locus and mean heterozigosity. Genetic similarity was calculated by simple matching coefficient and summarized in the group average phenogram. Fourteen loci and 35 alleles were detected. The loci that presented larger diversity were G6pdh-1, Acp-1 and Skdh-1. The percentage of polymorphic loci ranged from 3.57% to 64.29%; the mean number of alleles ranged from 0.04 to 1.64 and; the mean heterozigosity varied from 0.036 to 0.321. The lower values observed in the interval of variation of the average heterozigosity are consistent with the narrow genetic basis and the width of this interval can be related to the natural or forced hybridization degree of each clone. The genetic similarity ranged from 65% to 100%, and 70 clones were ranked into the interval of 85% to 100%, which confirms the narrowing of the genetic basis of the species and thereby resulting in the homogeneity of the cultivated clones.
Piper nigrum L.; genetic breeding; germplasm, isozymes
