Resumo

LEGARIA SOLANO, J. Porfirio. Genetic diversity in some species of amaranth (Amaranthus spp.). Rev. fitotec. mex [online]. 2010, vol.33, n.2, pp.89-95. ISSN 0187-7380.

In this research, 103 accesions classified within races of three cultivated species of Amaranthus: A. hypochondriacus represented by races 'Mercado' (7), 'Azteca' (38), 'Nepal' (30) and 'Mixteco' (1); A. caudatus, 'Sudamericana' race (12); and A. cruentus, 'Mexicana' race (15); were analyzed to determine genetic diversity among and within them, to obtain the corresponding genetic fingerprints, and to carry out comparisons for differentiating and distinguishing between the genetic variants. Analysis of 141 RAPD fragments generated from 16 primers revealed that A. hypochondriacus and A. caudatus are genetically most similar to each other compared to A. cruentus. In A. hypochondriacus, races 'Mercado' and 'Azteca' are genetically more related between them than with 'Nepal'. In Amaranthus there is a higher genetic diversity within species and races than among species and races. The percentage of polymorphic loci between populations was 73.05 % and within populations the genetic variability was low, with polymorphism levels of 27.66 % for A. caudatus race 'Sudamericana' and 65.96 % in A. hypochondriacus race 'Azteca'. Nei's coefficient of diversity (N) of all loci studied in the amaranth populations was 0.15, confirming a low diversity within populations. The level of genetic flow (Nm) was 1.43, indicating that less than two migrants per generation are exchanged between the populations.

Palavras-chave : Amaranthus spp.; genetic diversity; RAPD.