Diversification history and hybridisation of Dacrydium (Podocarpaceae) in remote Oceania

We examined evolutionary relationships, hybridisation and genetic diversity in species of Dacrydium (Podocarpaceae) in Remote Oceania, where it is restricted to New Caledonia and Fiji. We used cpDNA sequence (trnL–trnF) data to construct a phylogeny and estimate taxon divergence by using a relaxed m...

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Main Authors:	Keppel, Gunnar, Prentis, P., Biffin, E., Hodgskiss, P., Tuisese, S., Tuiwawa, V., Lowe, A.
Format:	Journal Article
Published:	CSIRO Publishing 2011
Online Access:	http://hdl.handle.net/20.500.11937/18344

id	curtin-20.500.11937-18344
recordtype	eprints
spelling	curtin-20.500.11937-183442017-09-13T15:58:57Z Diversification history and hybridisation of Dacrydium (Podocarpaceae) in remote Oceania Keppel, Gunnar Prentis, P. Biffin, E. Hodgskiss, P. Tuisese, S. Tuiwawa, V. Lowe, A. We examined evolutionary relationships, hybridisation and genetic diversity in species of Dacrydium (Podocarpaceae) in Remote Oceania, where it is restricted to New Caledonia and Fiji. We used cpDNA sequence (trnL–trnF) data to construct a phylogeny and estimate taxon divergence by using a relaxed molecular clock approach. The phylogeny was verified using allozymes, which were also used to investigate genetic diversity of all species and the hybridisation dynamics of two endangered species, D. guillauminii and D. nidulum. Our results suggested that Dacrydium species in Remote Oceania form a monophyletic group that arose and diversified within the last 20 million years through long-distance dispersal and a range of speciation mechanisms. Whereas we detected no hybridisation between the Fijian species D. nausoriense and D. nidulum, we confirmed hybridisation between D. guillauminii and D. araucarioides in New Caledonia and determined introgression to be assymetric from the widespread D. araucarioides into the rare, restricted-range species D. guillauminii. In addition, D. guillauminii had lower genetic diversity than did the other species of Dacrydium studied, which had genetic diversity similar to that of other gymnosperms. Our results provided evidence for the recent and complex diversification of Dacrydium in Remote Oceania. In addition, low genetic diversity of and introgression from D. araucarioides, are of grave concern for the conservation of D. guillauminii. 2011 Journal Article http://hdl.handle.net/20.500.11937/18344 10.1071/BT10181 CSIRO Publishing fulltext
repository_type	Digital Repository
institution_category	Local University
institution	Curtin University Malaysia
building	Curtin Institutional Repository
collection	Online Access
description	We examined evolutionary relationships, hybridisation and genetic diversity in species of Dacrydium (Podocarpaceae) in Remote Oceania, where it is restricted to New Caledonia and Fiji. We used cpDNA sequence (trnL–trnF) data to construct a phylogeny and estimate taxon divergence by using a relaxed molecular clock approach. The phylogeny was verified using allozymes, which were also used to investigate genetic diversity of all species and the hybridisation dynamics of two endangered species, D. guillauminii and D. nidulum. Our results suggested that Dacrydium species in Remote Oceania form a monophyletic group that arose and diversified within the last 20 million years through long-distance dispersal and a range of speciation mechanisms. Whereas we detected no hybridisation between the Fijian species D. nausoriense and D. nidulum, we confirmed hybridisation between D. guillauminii and D. araucarioides in New Caledonia and determined introgression to be assymetric from the widespread D. araucarioides into the rare, restricted-range species D. guillauminii. In addition, D. guillauminii had lower genetic diversity than did the other species of Dacrydium studied, which had genetic diversity similar to that of other gymnosperms. Our results provided evidence for the recent and complex diversification of Dacrydium in Remote Oceania. In addition, low genetic diversity of and introgression from D. araucarioides, are of grave concern for the conservation of D. guillauminii.
format	Journal Article
author	Keppel, Gunnar Prentis, P. Biffin, E. Hodgskiss, P. Tuisese, S. Tuiwawa, V. Lowe, A.
spellingShingle	Keppel, Gunnar Prentis, P. Biffin, E. Hodgskiss, P. Tuisese, S. Tuiwawa, V. Lowe, A. Diversification history and hybridisation of Dacrydium (Podocarpaceae) in remote Oceania
author_facet	Keppel, Gunnar Prentis, P. Biffin, E. Hodgskiss, P. Tuisese, S. Tuiwawa, V. Lowe, A.
author_sort	Keppel, Gunnar
title	Diversification history and hybridisation of Dacrydium (Podocarpaceae) in remote Oceania
title_short	Diversification history and hybridisation of Dacrydium (Podocarpaceae) in remote Oceania
title_full	Diversification history and hybridisation of Dacrydium (Podocarpaceae) in remote Oceania
title_fullStr	Diversification history and hybridisation of Dacrydium (Podocarpaceae) in remote Oceania
title_full_unstemmed	Diversification history and hybridisation of Dacrydium (Podocarpaceae) in remote Oceania
title_sort	diversification history and hybridisation of dacrydium (podocarpaceae) in remote oceania
publisher	CSIRO Publishing
publishDate	2011
url	http://hdl.handle.net/20.500.11937/18344
first_indexed	2018-09-06T19:51:49Z
last_indexed	2018-09-06T19:51:49Z
_version_	1610889045427093504

Diversification history and hybridisation of Dacrydium (Podocarpaceae) in remote Oceania

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