Genome Differentiation in Lycoris Species (Amaryllidaceae) Identified by Genomic in situ Hybridization

The chromosomes of six Lycoris species and three interspecific hybrids were investigated using genomic in situ hybridization (GISH) to clarify the chromosome constitution in this genus. Total DNA from L. aurea (2n = 13, 9M + 4T) and L. sprengeri (2n = 22, 22A) was used as probe and blocking DNA, respectively. All the chromosomes of L. aurea (9M + 4T) and L. longituba (6M + 10T) were hybridized with probe DNA and were visualized as yellow labeled chromosomes, while those of L. sprengeri (22A), L. radiata var. pumila (22A) and L. sanguinea (22A) remained unlabeled and appeared as red chromosomes. Eight labeled (3M + 5T) and 22 unlabeled chromosomes (20A + 1M ′ + 1m) were observed in GISH of L. incarnata. Eight labeled (3M + 5T) and 33 unlabeled chromosomes (31A + 1M ′ + 1m) were detected in GISH of three interspecific hybrids between L. incarnata and 3 diploid species. The distinction between M + T and A type chromosomes at the DNA sequence level by GISH demonstrated that genome differentiation had occurred in the genus Lycoris.