Ribosomal DNA locus variation and REMAP analysis of the diploid and triploid complexes of Lilium lancifolium

Abstract

Lilium lancifolium Thunb. (2n = 2x = 24) is a cytologically conspicuous species with both diploids and triploids in nature. Cytological and molecular genetic analyses were carried out in both diploids and triploids that were collected from 55 geographical locations in Korea, Japan, and China. While the 5S rRNA gene loci were located at duplicated loci on the long arm of chromosome 2, the 45S rRNA gene loci were present in chromosomes 1, 2, 4, 6, 7, and 11. While the loci on chromosomes 1 and 7 were constant, the loci on chromosomes 2, 4, 6, 7, and 11 were variable in some plants so that the L. lancifolium accessions were grouped into 7 cytotypes in diploids and 12 cytotypes in triploids. REMAP marker analysis revealed that the diploids were classified into seven clusters, and the triploids were classified into a large cluster. Geographic, cytological, and genetic differentiations were not related in both the diploid and triploid accessions of L. lancifolium. Thus, current genetic variations occurred prior to the geographic differentiation in both diploids and triploids, and the 45S rDNA cytotype variations occurred after geographic differentiation in the current habitats of L. lancifolium.