Differential Fluorescent Chromosome Banding of Four Species in Haworthia Duval (Aloaceae)

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The karyotypes of 4 Haworthia species viz. H. papillosa Haw., H. fasciata Haw., H. limifolia Marloth and H. reinwardtii Haw. were compared after differential staining with orcein, CMA and DAPI. In H. papillosa and H. fasciata 2n=14 chromosomes were found. H. limifolia and H. reinwardtii possessed 2n=21 and 2n=35 chromosomes, respectively. These 4 species possessed distinct bimodal karyotypes. Two satellites were found one in each on the long arm of 2 large chromosomes of these 4 species. The staining property of satellites was different in each species. In H. papillosa, satellites were found in orcein and CMA-staining, negative satellites were found in DAPI-staining. H. fasciata showed satellites in CMA and DAPI, whereas no satellite was found in orcein staining. Two CMA-positive and one DAPI-negative satellites were found in H. limifolia, but none in orcein staining. In H. reinwardtii, satellites were found in orcein staining and not in CMA- and DAPI-staining. No DAPI-positive or negative band was found on the chromosomes in these 4 species. H. papillosa possessed an interstitial stable CMA-positive band on the long arm of a chromosome in pair I. This kind of banded chromosome was absent in other 3 species and thus can be used as a marker. The CMA-banded karyotype of H. limifolia showed a probable occurrence of paracentric inversion and deletion. It also indicated the presence of different genomes with partial homology. Therefore, H. limifolia seems to be a segmental allotriploid. 2n chromosome number together with orcein, CMA and DAPI karyotypes suggests H. reinwardtii as an autopentaploid.