Evolutionary Biology of <i>Trillium</i> and Related Genera (Trilliaceae) I. Restriction Site Mapping and Variation of Chloroplast DNA and its Systematic Implications

Abstract

Abstract A physical map of chloroplast DNA ( cp DNA) was constructed for Trillium kamtschaticum using three restriction enzymes, Apal, Pstl and Xho l. The chloroplast genome is 154.5 kbp in size with each portion of the inverted repeat 26.5 kbp in length, separated by large (82.7 kbp) and small (18.8 kbp) single copy regions. The cp DNA of T. kamtschaticum is similar in structure to the cp DNAs of most angiosperms thus far studied. Chloroplast DNA variation in 25 taxa of Trillium was investigated using 14 restriction enzymes, with Paris tetraphylla as an outgroup. Phylogenetic analysis showed that sessile‐flowered species (subgenus Phyllantherum ) form a monophyletic group. Pedicellate‐flowered species do not form a monophyletic group, and belong to at least three different groups. T. kamtschaticum , an East Asian diploid species, was found to be most closely related to a group of species from eastern North America.