ITS DNA sequence relationships between Lilium concolor Salisb., L. dauricum Ker-Gawl. and their putative hybrid, L. maculatum Thunb.

 Cycle sequencing of the ITS region of nuclear ribosomal DNA of L. concolor, L. dauricum and L. maculatum generated surprisingly homogenous sequences from these three species. Analysis of the few (13 out of 639) polymorphic nucleotide sites in the ITS region produced results that do not support the belief that L. maculatum is a hybrid of the two other species. Neighbor-Joining analysis of the genetic distances calculated using the Kimura 2-parameter model of base substitution confirmed the close relationship between L. dauricum and L. maculatum. The phylogenetic tree, in conjunction with the distribution pattern and morphological similarities of the two species, suggest that L. maculatum is derived from the more widely distributed L. dauricum. The results also revealed that there is sufficient molecular divergence between L. maculatum and L. dauricum to support their status as separate species. Received: 4 June 1998 / Accepted: 15 July 1998