Cytogenetics of Crotalaria IX

Mitotic Complements in 19 Species

Abstract

Detailed karyotypes were studeid in 19 species of Crotalaria, of which seven have not been investigated so far. Fifteen species were diploids (2n=16) and four were tetraploids (2n=32). Karyomorphology was alsmost uniform in various species. The basic karyotype consisted of eight chromosomes containging three long and five medium chromosomes. Various species differed in the number of V, L, and J chromosomes. Nucleolar chromosomes in the form of secondary constriction in longest pair were observed in eight species. Three broad categories of nu-cleolar chromosomes were recognised. Three species had only one nucleolar chromo-some. There was an overall stability of chromosome morphology and symmetry, therefore species differentiation can not be correlated with chromosomal differentiation. Polyploidy is rare and has not played any significant role in the speciation of the genus. It has been concluded that true basic number is eight.