Karyotype Analysis in Lycoris rosea Traub et Moldenke

The present paper embodies the results of a karyotypic analysis for the species Lycoris rosea Traub et Moldenke. The voucher specimen, J. Z. Lin 004 is preserved in the Herbarium of Hanchow Botanical Garden. The chromosome number in root tip cells is found for the first time to be 22, and the karyotype is shown to be an asymmetrical one with rod-shaped chromosomes. A photomicrograph, the karyotype and the idiogram are shown in Figs. 1-2. According to Levan et aL.^5], the karyotype formula of the species is 2n=22=22t. But based on the classification presented by Bose and Flory^1], the karyotype formula should be expressed as 2n=22 =C22, and the chromosomes are all with subterminal constrictions. If regarding 11 as the basic number and centric fusion as the major tendency of karyotype evolution as proposed by Inariyama^2], Stebbins^6], and Jones^3,4] in particular, L. rosea would be considered as one of the most primitive species in Lycoris from point of view of karyotype evolution. Reciprocal translocations and centric fusions would give rise to V-shaped chromosomes. Consequently, the successive decrease in chromosome number may have taken place in the speciation of the genus under discussion. Yet further evidence seems ne-cessary for the verification of the speculation.