Somatic chromosome differentiation in three species of the Byblis liniflora complex (Byblidaceae)

Abstract

We conducted chromosomal characterizations of three species in the Byblis liniflora complex using sequential fluorescent staining with chromomycin A₃ (CMA) and 4',6-diamidino-2-phenylindole (DAPI), and fluorescence in situ hybridization method. Byblis filifolia and B. rorida had the diploidal chromosome number of 2n=16, while B. liniflora had the tetraploidal chromosome number of 2n=32. All chromosomes of three species were median-centromeric. The primary constrictions, which contain centromeric regions, showed slightly CMA-positive stainability. Two CMA-positive DAPI-negative segments were observed on two chromosomes of the diploids B. rorida and B. filifolia, and the tetraploid B. liniflora. The 45S rDNA signals were detected on two chromosomes of the diploid and the tetraploid species, respectively. The positions of the 45S rDNA were corresponded to CMA-positive DAPI-negative segments.