Cytogenetic studies on Brazilian Xyris species (Xyridaceae) |
| |
| Authors: | Ana M Benko-Iseppon Maria G L Wanderley |
| |
| Institution: | Universidade Federal de Pernambuco, CCB, Dept Genética, Av Prof Moraes Rego, s/no., 50.732–970, Recife, PE, Brazil;;Instituto de Botânica, Jardim Botânico de São Paulo, Av Miguel Stefano, 3687, 01051–000, São Paulo, SP, Brazil |
| |
| Abstract: | Cytological features are presented for the first time for 12 species and one natural hybrid from 16 Brazilian populations of the genus Xyris , including members of two sections ( Xyris and Nematopus ). The results are compared with a review of all available chromosome numbers previously reported for the genus. All analysed species show semi-reticulate interphase nuclei and prophase to prometaphase chromosomes with heterogeneous condensing behaviour. Chromosome numbers varied between 2 n = 26 and 2 n ≈ 108. In Brazil especially, the karyological differentiation of Xyris seems to be generally characterized by dysploid and polyploid increase of the chromosome number, possibly after interspecific hybridization. This is the first cytological study including species of the section Nematopus and the first karyological investigation including South American species of the genus Xyris . © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 138 , 245–252. |
| |
| Keywords: | chromosomes condensing behaviour dysploidy evolution interphase nuclei karyoevolution Monocotyledoneae Nematopus polyploidy |
|
|
