| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
3Institute for Systematics and Population Biology, University of Amsterdam, Kruislaan 318, NL-1098 SM Amsterdam, The Netherlands; and 4Institute for Plant Genetics and Crop Plant Research IPK, Corrensstrasse 3,D-06466 Gatersleben, Germany
Restriction site mutations and trnL(UAA)-trnF(GAA) intergenic spacer length variants in the chloroplast genome were used to investigate the phylogenetic relationships among 53 Australian and New Zealand Microseris populations and to assess their position within their primarily North American genus. The study was performed to enhance understanding of evolutionary processes within this unique example of intercontinental dispersal and subsequent adaptive radiation. A southern blot method using four-base restriction enzymes and fragment separation on polyacryamide gels resulted in 55 mutations of which 30 were potentially phylogenetically informative. Most mutations were small indels of <162 bp, 80% of which were <20 bp. The small indels were useful for phylogenetic reconstruction of Australasian Microseris as judged by the high consistency indexes. The results confirmed the monophyly of the Australian and New Zealand Microseris. The occurrence of "hard" basal polytomies in the most parsimonious trees indicated that rapid radiation has occurred early in the history of the taxon. The monophyly of M. lanceolata, which includes the self-incompatible ecotypes of the Australian mainland, was confirmed. Within this species three clades were found that reflect more geographic distribution than morphological entities, suggesting that migration and possibly introgression between different ecotypes, or parallel evolution of similar adaptations, has occurred. One of the three clades was supported by a 162-bp deletion in the trnL-trnF spacer, while a subgroup of this exhibited also a tandemly repeated trnF exon. The data were inconclusive about the monophyly of the second Australasian species, M. scapigera, which comprises the New Zealand, Tasmanian, and autofertile ecotypes of Australia.
Key Words: adaptive radiation • Asteraceae • cpDNA RFLPs • indels • long-distance dispersal • Microseris • phylogeny • trnL(UAA)-trnF(GAA)
This article has been cited by other articles:
|
|
 |
|
  M. E. Mort, J. K. Archibald, C. P. Randle, N. D. Levsen, T. R. O'Leary, K. Topalov, C. M. Wiegand, and D. J. Crawford Inferring phylogeny at low taxonomic levels: utility of rapidly evolving cpDNA and nuclear ITS loci Am. J. Botany, February 1, 2007; 94(2): 173 - 183. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. A. Shepherd, M. Waycott, and A. Calladine Radiation of the Australian Salicornioideae (Chenopodiaceae)--based on evidence from nuclear and chloroplast DNA sequences Am. J. Botany, September 1, 2004; 91(9): 1387 - 1397. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Holderegger and R. J. Abbott Phylogeography of the Arctic-Alpine Saxifraga oppositifolia (Saxifragaceae) and some related taxa based on cpDNA and ITS sequence variation Am. J. Botany, June 1, 2003; 90(6): 931 - 936. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Samuel, T. F. Stuessy, K. Tremetsberger, C. M. Baeza, and S. Siljak-Yakovlev Phylogenetic relationships among species of Hypochaeris (Asteraceae, Cichorieae) based on ITS, plastid trnL intron, trnL-F spacer, and matK sequences Am. J. Botany, March 1, 2003; 90(3): 496 - 507. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
