Abstract

We examined leaf morphological characteristics, ISSR (inter-simple sequence repeat) genetic polymorphisms and ITS (rDNA internal transcribed spacer) molecular markers in 12 endemic species of Cinnamomum in Taiwan to determine their cladistic relationships. The leaf morphology and ISSR data support the division of the genus into sections Camphora and Cinnamomum. The genetic relationship betweenCinnamomum camphora and Cinnamomum micranthum is very close; both species share a specific 11 bp deletion in their ITS sequences. A close relationship betweenCinnamomum insularimontanum and Cinnamomum macrostemon was supported by leaf morphology, ISSR and ITS data and the ITS analysis indicates thatCinnamomum subavenium is closely related to these two species. The ITS analysis also indicates that Cinnamomum japonicum, Cinnamomum austrosinense andCinnamomum reticulatum are closely related. Leaf morphology and ISSRs also support the kinship between C. japonicum and C. austrosinense. The ITS data support a close cluster consisting of C. osmophloeum, C. camphora and C. micranthum, suggesting that Cinnamomum osmophloeum might be a key species in the evolutionary transition from section Camphora to section Cinnamomum. Our results demonstrate that ISSR and ITS markers can clearly identify the 12 endemicCinnamomum species in Taiwan.

Key words: Cinnamomum, morphology, taxonomy, ISSR (inter-simple sequence repeat), ITS (internal transcribed spacer), phylogeny.

Abbreviation

ISSR, Inter-simple sequence repeat; ITS, internal transcribed spacer; NJ, neighbor joining; MP, maximum parsimony; PCR, polymerase chain reaction; ETS, external transcribed spacer; OUT, operational taxonomic unit;UPGMA, unweighted pair group method with arithmetic mean; CTAB, cetyl trimethyl ammonium bromide; DMSO, dimethyl sulfoxide; MCL, maximum composite likelihood; NCBI, National Center for Biotechnological Information