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Plant Phylogeny (plant + phylogeny)

Distribution by Scientific Domains
Life Sciences100%

Selected Abstracts

Plant Phylogeny and the Origin of Major Biomes

AUSTRAL ECOLOGY, Issue 7 2005
DAVID BOWMAN
No abstract is available for this article. [source]

Distribution of the anther-smut pathogen Microbotryum on species of the Caryophyllaceae

NEW PHYTOLOGIST, Issue 1 2010
Michael E. Hood
Summary ,Understanding disease distributions is of fundamental and applied importance, yet few studies benefit from integrating broad sampling with ecological and phylogenetic data. Here, anther-smut disease, caused by the fungus Microbotryum, was assessed using herbarium specimens of Silene and allied genera of the Caryophyllaceae. ,A total of 42 000 herbarium specimens were examined, and plant geographical distributions and morphological and life history characteristics were tested as correlates of disease occurrence. Phylogenetic comparative methods were used to determine the association between disease and plant life-span. ,Disease was found on 391 herbarium specimens from 114 species and all continents with native Silene. Anther smut occurred exclusively on perennial plants, consistent with the pathogen requiring living hosts to overwinter. The disease was estimated to occur in 80% of perennial species of Silene and allied genera. The correlation between plant life-span and disease was highly significant while controlling for the plant phylogeny, but the disease was not correlated with differences in floral morphology. ,Using resources available in natural history collections, this study illustrates how disease distribution can be determined, not by restriction to a clade of susceptible hosts or to a limited geographical region, but by association with host life-span, a trait that has undergone frequent evolutionary transitions. [source]

Linnaeus' sexual system and flowering plant phylogeny

NORDIC JOURNAL OF BOTANY, Issue 1-2 2007
Birgitta Bremer
Carl Linnaeus brought order to the knowledge of plants and animals by arranging all known species in encyclopaedic works. He proposed a system of plants, the sexual system, based on the number and arrangement of male and female organs. His artificial sexual system has since long been replaced by ,natural' or phylogenetic systems but there has never been a comprehensive comparison of the sexual system with modern plant classification. The currently most often used classification of flowering plants is the APG-system. It is based on comprehensive phylogenies of flowering plants, reconstructed by analyses of DNA data. The APG-system covers all flowering plants which are classified in 453 families and these are classified in 45 orders. Most of the species were not known at time of Linnaeus. Families and orders in the APG-system are arranged in larger informal groups representing major branches in the flowering plant phylogenetic tree. Three such groups are the monocots, the rosids, and the asterids. I have examined all genera published in Species plantarum (1753) and classified them according to order and major groups in the APG-system. All classes except one, number 15 Tetradynamia, comprises groups of unrelated plants. Not surprisingly, the sexual system does not display what we know today about plant relationships. As is evident from this analysis, there is little correspondence between the sexual system and the APG-system. This does not mean that the sexual system has been useless or misleading. When it was introduced, it formed the basis for much intensified research and increased knowledge of plants. [source]

Taxon sampling and seed plant phylogeny

CLADISTICS, Issue 5 2002
Catarina Rydin
We investigated the effects of taxon sampling on phylogenetic inference by exchanging terminals in two sizes of rbcL matrices for seed plants, applying parsimony and bayesian analyses to ten 38-taxon matrices and ten 80-taxon matrices. In comparing tree topologies we concentrated on the position of the Gnetales, an important group whose placement has long been disputed. With either method, trees obtained from different taxon samples could be mutually contradictory and even disagree on groups that seemed strongly supported. Adding terminals improved the consistency of results for unweighted parsimony, but not for parsimony with third positions excluded and not for bayesian analysis, particularly when the general time-reversible model was employed. This suggests that attempting to resolve deep relationships using only a few taxa can lead to spurious conclusions, groupings unlikely to be repeatable with different taxon samplings or larger data sets. The effect of taxon sampling has not generally been recognized, and phylogenetic studies of seed plants have often been based on few taxa. Such insufficient sampling may help explain the variety of phylogenetic hypotheses for seed plants proposed in recent years. We recommend that restricted data sets such as single-gene subsets of multigene studies should be reanalyzed with alternative selections of terminals to assess topological consistency. [source]