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Abstract Detail



Systematics Section/ASPT

Givnish, Thomas [1], Bean, Gregory [2], Ames Sevillano, Mercedes [3], Lyon, Stephanie [4], Sytsma, Kenneth [1].

Phylogeny, floral evolution, and inter-island dispersal in Hawaiian Clermontia (Campanulaceae) based on ISSR variation and plastid spacer sequences.

Previous studies based on DNA restriction-site and sequence variation have shown that the Hawaiian lobeliads are monophyletic and that the two largest genera, Cyanea and Clermontia, diverged from each other ca. 9.7 Mya. Sequence divergence among species of Clermontia is quite limited, however, and extensive hybridization is suspected, which has interfered with production of a well-resolved molecular phylogeny for the genus. Clermontia is of considerable interest because several species posses petal-like sepals, raising the question of whether such a homeotic mutation has arisen once or several times. In addition, morphological and molecular studies have implied different patterns of inter-island dispersal within the genus. Here we use nuclear ISSRs (inter-simple sequence repeat polymorphisms) and five plastid non-coding sequences to derive biparental and maternal phylogenies for Clermontia. Our findings imply that (1) Clermontia is not monophyletic, with Cl. pyrularia nested within Cyanea and apparently an intergeneric hybrid; (2) the earliest divergent clades within Clermontia are native to Kaua`i, then O`ahu, then Maui, supporting the progression rule of dispersal down the chain toward progressively younger islands, although that rule is violated in later-evolving taxa in the ISSR tree; (3) almost no sequence divergence among several Clermontia species in 4.5 kb of rapidly evolving plastid DNA; (4) several apparent cases of hybridization/introgression or incomplete lineage sorting (i.e., Cl. oblongifolia, peleana, persicifolia, pyrularia, samuelii, tuberculata), based on extensive conflict between the ISSR and plastid phylogenies; and (5) two origins and two losses of petaloid sepals, or – perhaps more plausibly – a single origin and two losses of this homeotic mutation, with its introgression into Cl. persicifolia. Our phylogenies are better resolved and geographically more informative than others based on ITS and 5S-NTS sequences and nuclear SNPs, but agree with them in supporting Clermontia’s origin on Kaua`i or some older island and dispersal down the chain subsequently.

Broader Impacts:


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1 - University of Wisconsin, Department of Botany, Birge Hall, 430 Lincoln Drive, Madison, WI, 53706, USA
2 - Monsanto, Chesterfield Village, MO, 63017, USA
3 - Promega, Madison, WI, 53711, USA
4 - University of Wisconson-Madison, Botany, 430 Lincoln Dr, Madison, WI, 53706, USA

Keywords:
Adaptive Radiation
BEAST
DEC
historical biogeography
homeotic mutation
PISTILLATA.

Presentation Type: Oral Paper:Papers for Sections
Session: 35
Location: Versailles Ballroom/Riverside Hilton
Date: Tuesday, July 30th, 2013
Time: 1:45 PM
Number: 35002
Abstract ID:871
Candidate for Awards:None


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