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ARS Home » Pacific West Area » Hilo, Hawaii » Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center » Tropical Crop and Commodity Protection Research » Research » Publications at this Location » Publication #316752

Title: An expanded Metrosideros (Myrtaceae) to include Carpolepis and Tepualia based on nuclear genes

item PILLON, YOHAN - University Of Hawaii
item LUCAS, EVE - Royal Botanical Gardens
item JOHANSEN, JENNIFER - University Of Hawaii
item SAKISHIMA, TOMOKO - University Of Hawaii
item HALL, BRIAN - University Of Hawaii
item Geib, Scott
item STACY, ELIZABETH - University Of Hawaii

Submitted to: Systematic Botany
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/21/2015
Publication Date: 9/22/2015
Citation: Pillon, Y., Lucas, E., Johansen, J.B., Sakishima, T., Hall, B., Geib, S.M., Stacy, E.A. 2015. An expanded Metrosideros (Myrtaceae) to include Carpolepis and Tepualia based on nuclear genes. Systematic Botany. 40(3):782-790.

Interpretive Summary: This manuscript reports a systematic analysis of trees in the genus Metrosideros (which include the Hawaiian endemic Ohi’a species). Using a combination of 5 nuclear genes derived from high-throughput sequencing, and analysis using a variety of approaches (Bayesian, concordance, coalescent). The results from this study reveals poor support for former taxonomic relationship within this group, particularly in that the genera Carpolepis and Tepualia are not supported as distinct from the Metrosideros, but rather nested within. Thus, this manuscript adopts a broadening of the Metrosideros to include 60 species and redescribing of several species within the genera.

Technical Abstract: The genus Metrosideros (Myrtaceae) comprises 50-60 species, found largely across the Pacific Islands. The relationships within this genus, including the circumscriptions of the subgenera Mearnsia and Metrosideros and their relationships with the other members of the tribe Metrosidereae, namely the New Caledonian endemic genus Carpolepis and the South American Tepualia, are poorly understood. Phylogenetic analyses were carried out using previously published ITS sequences, covering most species of the tribe, and new sequences of five single-copy nuclear genes on a reduced sampling. The independent and combined analyses of the five nuclear genes using a range of approaches, including Bayesian single-gene, concatenated (MrBayes), concordance (BUCKy) and coalescent (*BEAST) analyses, yielded different topologies, indicating important conflicts among individual gene phylogenetic signals. The deep relationships within the tribe Metrosidereae remain poorly resolved, but our results indicate that the species of Carpolepis and Tepualia are likely nested in the genus Metrosideros. A broad circumscription of the genus Metrosideros is therefore adopted, and the new combinations Metrosideros laurifolia var. demonstrans, Metrosideros tardiflora and Metrosideros vitiensis are here published.