Coughlan, Patricia and Carolan, James C. and Hook, Ingrid L.I. and Kilmartin, Lisa and Hodkinson, Trevor R.
(2020)
Phylogenetics of Taxus Using the Internal Transcribed
Spacers of Nuclear Ribosomal DNA and Plastid
trnL-F Regions.
Horticulturae, 6 (1).
pp. 1-16.
ISSN 2311-7524
Abstract
Taxus is a genus of trees and shrubs with high value in horticulture and medicine as a
source of the anticancer drug paclitaxel. The taxonomy of the group is complex due to the lack of
diagnostic morphological characters and the high degree of similarity among species. Taxus has
a wide global geographic distribution and some taxonomists recognize only a single species with
geographically defined subgroups, whereas others have described several species. To address these
differences in taxonomic circumscription, phylogenetic analyses were conducted on DNA sequences
using Maximum Likelihood, Bayesian Inference and TCS haplotype networks on single and combined
gene regions obtained for the nuclear ribosomal ITS region and the plastid trnL intron and trnL-F
intergenic spacer. Evidence is presented for the sister group status of Pseudotaxus to Taxus and the
inclusion of Amentotaxus, Austrotaxus, Cephalotaxus and Torreya within Taxaceae. Results are consistent
with the taxonomic recognition of nine species: T. baccata, T. brevifolia, T. canadensis, T. cuspidata, T.
floridana, T. fuana, T. globosa, T. sumatrana and T. wallichiana, but evidence is found for less species
distinction and considerable reticulation within the T. baccata, T. canadensis and T. cuspidata group. We
compare the results to known taxonomy, biogeography, present new leaf anatomical data and discuss
the origins of the hybrids T. ×media and T. ×hunnewelliana.
| Item Type: |
Article
|
| Keywords: |
biogeography; hybridization; Taxus; nrITS; paclitaxel; phylogenetics; taxaceae; taxol;
trnL-F; |
| Academic Unit: |
Faculty of Science and Engineering > Biology |
| Item ID: |
14939 |
| Identification Number: |
https://doi.org/10.3390/horticulturae6010019 |
| Depositing User: |
James Carolan
|
| Date Deposited: |
19 Oct 2021 14:15 |
| Journal or Publication Title: |
Horticulturae |
| Publisher: |
MDPI |
| Refereed: |
Yes |
| URI: |
|
| Use Licence: |
This item is available under a Creative Commons Attribution Non Commercial Share Alike Licence (CC BY-NC-SA). Details of this licence are available
here |
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