Chromosome studies in the Complex Galactia-Collaea-Camptosema (Diocleinae, Phaseoleae, Papilionoideae, Fabaceae)

Abstract

The genera Galactia, Camptosema and Collaea are grouped in a complex due to exomorphological similarities and different criteria have been adopted to delimit them. The objective of this contribution is to analyse the chromosomal characteristics in some species from the austral regions of South America. Chromosome numbers and karyotypes of four species of Galactia (G. texana, G. latisiliqua, G. fiebrigiana var. sericophylla and G. striata), one species of Collaea (C. stenophylla) and one species of Camptosema (C. rubicundum) were studied. Chromosome numbers of G. texana (2n=20), G. striata (2n=20) and Collaea stenophylla (2n=20) confirm previous reports, while those of G. latisiliqua (2n=20), G. fiebrigiana var. sericophylla (2n=20) and Camptosema rubicundum (2n=22) are presented for the first time. The karyotypes of Galactia (16m + 4m-sm) and Collaea species (14m + 2m-sm + 4sm) showed no distinctive characteristics, since both genera are characterised by small median chromosomes. Camptosema rubicundum presented a different chromosome number, as well as a distinctive karyotype morphology: 12m + 2m-sm + 4sm + 4st-t; these features permit to characterise this species from the others included into this study. © 2003 Taylor & Francis Group, LLC.