Karyological studies in five wild species of Amaranthus

EDUARDO J. GREIZERSTEIN, CARLOS A. NARANJO Y LIDIA POGGIO

CYTOLOGIA

UNIV TOKYO CYTOLOGIA

Año: 1997 vol. 62 p. 115 - 120

0011-4545

Cytogenetic program in Amaranthus have been devised in our laboratory since 1988, in order to improve the karyological characterization of the species and cultivars, increase the knowledge of genetic resources and explore evolutionary trends (Greizerstein and Poggio 1992, 1994, 1995). Two chromosome numbers have been reported in the genus (2n = 32, 2n = 34) and in some cases both numbers occur in the same species, in addition to that of A dubius L, the only species with 2n = 64. Pal et al. (1982) suggested that the gametic number n= 17 originated from the n=16 through primary trisomy. Greizerstein and Poggio (1992, 1994), on the basis of the cytogenetic analysis of interspecific hybrids support this hypothesis, and propose that the species with 2n = 32 are polyploids (basic number x = 8) and that X| = 16 is a derived basic number. The basic number x2= 17 would have appeared later by primary trisomy.