A comparison of Karyotype, Ag-NOR bands and DNA contentin Amaryllisand Hippeastrum (Amaryllidaceae).

NARANJO C.A., LIDIA POGGIO

KEW BULLETIN

Royal Botanic Gardens

Lugar: Richmond; Año: 1988 vol. 42 p. 317 - 325

0075-5974

Summary. This paper presents new data useful in the consideration of the relationships betvveen Amaryllis belladonna L., type species of the monotypic South African genus, and species of the South American genus Hippeastrum Herb. A. belladonna (2n = 22) has a karyotype comprising 4 pairs m + 1 pair m-sm + 6 pairs sm chromosomes; the m pairs are shorter than the other ones. The pair m-sm has a terminal satelüte on the short arm; the secondary constriction proximal to this is a nucleolar organizer, as demonstrated by Ag-NOR banding. The constant basic karyotype in Hippeastrum (x = 11) is more asymmetrical and comprises 4 m + 4 sm + 3 st; the m are shorter than the others. One st chromosome has a terminal nucleolar organizer (NOR) secondary constriction on the short arm. Furthermore, the karyotype is also more asymmetrical because it has more variation of chromosome total length. The DNA content in A. belladonna is 2C = 38.29 pg while in diploid species of Hippeastrum studied, it ranges from 26.90 pg to 34.18 pg, being represented in this paper by H. parodii with 2C = 29.93 pg. These results indícate that important chromosome differences exist betvveen South African and South American taxa. These differences are supported by morphological and anatomical studies reported by other authors.