Comparative C-banding and Fluorescent-banding Analysis of Seven Species of Drosera (Droseraceae).

Abstract

Seven species of Australian Drosera were investigated for a comparative karyotype analysis with different banding schedules, namely Giemsa C-band fluorescent- (CMA- and DAPI-) bandings. Chromosome numbers of D. callistos (2n=28), D. scorpioides (2n=18), D. ericksonea (2n=28), D. pulchella (orange flower) (2n=15), D. scorpioides (2n=16) and D. spilos (2n=18) were reported here for the first time. All the taxa showed asymmetric karyotype in chromosome length. Bimodal karyotypes were observed in D. callistos, D. ericksonea, D. pulchella (pink flower) that perhaps resulted from interspecific hybridization. Sat-chromo-somes were found in D. callistos, D. petiolaris, D. pulchella (pink flower) and D. spilos. The appearance of satellites were strictly stain specific. Three chromosomes of D. pulchella (pink flower) and two chromosomes of D. scorpioides could be identified by their specific response to Giemsa stain. Fluorescent banding revealed that genomic DNA of D. callistos and D. scorpioides rich in AT base composition. A marked differences regarding chromosome numbers, orcein, C-banded and fluorescent banded karyotypes were observed between the two taxa of D. pulchella (pink flower and orange flower), thus needs apeer reinvestigation to elucidate their taxonomic position.