Karyological Studies in Some African Species of the Genus Sesbania (Fabaceae).

Abstract

Karyological criteria of 15 African species of Sesbania, including five new records, are presented. A diploid number of 2n =12 (x=6) has been found in 12 species, 2n =14 (x=7) in onespecies and a tetraploid number of 2n =4x=24 was recorded in S. formosa and S. grandiflora. The karyotype in the examined species is symmetric. However, considerable variation exists in chromo-some size among the species studied.The result of the present study confirm that x=6 may be considered the basic number in the genus. Our observations further indicate that Sesbania is a primitive genus in its tribe Robinieae from which other genera may have evolved through aneuploid and polyploid changes.