Reversible Fluorescent Chromosome Banding in Three Crinum spp. (Amaryllidaceae)

Abstract

Mitotic metaphase chromosomes of Crinum latifolium L., C. asiaticum L. and C. amoenum Roxb. (Fam.-Amaryllidaceae) were stained with orcein, CMA and DAPI. C. latifolium possessed 2n=33 chromosomes whereas the other two species had 2n=22 chromosomes. All these species showed 2 bright and thick CMA-positive bands at the intercalary regions of the long arms in 2 sub-metacentric chromosomes of group/pair VI. In addition, C. latifolium possessed another 2 CMA-positive bands 1 in each side of the centromere in a chromosome of group IX. After counter staining with DAPI, the intercalary CMA-banded regions of C. asiaticum and C. amoenum showed deep DAPI-negative bands. It indicates the possible presence of NORs. No DAPI-negative band was found in C. latifolium. In these 3 species 8–12 DAPI-positive bands were observed on various chromosomes. In C. asiaticum and C. amoenum these bands were located in the centromeric regions whereas in C. latifolium, most of the bands appeared in the long arms of respective chromosomes. The presence of 2n=33 chromosomes, the number and distribution of CMA and DAPI-bands, together with gigas features indicated that the specimen of C. latifolium studied is not an auotriploid, may be an allotriploid or a segmental one.