Assessing the Utility of Isozyme Number for Determining Ploidal Level

In order to evaluate the utility of isozyme number for estimating ploidal level in ancient polyploid (paleopolyploid) plant species, isozyme number was determined for species of the putatively paleopolyploid genus Helianthus with n = 17, and compared with those of a species of Heliomeris with n = 8. Electrophoretic examination of 13 enzymes revealed the presence of nine duplicated isozymes in Helianthus annuus and Helianthus bolanderi and six duplicated isozymes in Heliomeris multiflora. Thus, there is little difference in isozyme number between ploidal levels. It is suggested that the lack of strong concordance between isozyme number and ploidal level may be due to gene silencing in Helianthus and the presence of gene duplications not resulting from polyploidy in both taxa

Morphological Stasis abd Molecular Divergence in the Intercontinental Disjunct Genus Datisca (Datiscaceae)

The genus Datisca comprises two species and has an intercontinentally disjunct distribution: D. cannabina is native to southwest and central Asia, whereas D. glomerata is distributed from northern California to northern Baja California. In 1975, Axelrod proposed a geohistorical scenario to account for such Madrean-Tethyan links, suggesting that these disjunctions resulted from migration across the mid-Atlantic from the Paleogene up to the Neogene, approximately 23 to 65 m.y.a. The two species are quite similar in most phenotypic traits which have been studied to date. The major difference between the two involves their breeding system: D. cannabina is dioecious while D. glomerata is apparently androdioecious. Despite these similarities, Nei\u27s mean genetic identity between the two species is I = 0.142. This is one of the lowest values yet reported for congeneric flowering plants and provides evidence for an ancient origin of the disjunction. Furthermore, the fact that the western populations of D. cannabina have a much higher genetic identity value with D. glomerata than does the eastern population supports the idea that dispersal occurred across the Atlantic. In addition, the population genetic structure of D. glomerata is consistent with an androdioecious breeding system

Some perspective on Molecular Ecology perspectives: Are women being left out?

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149698/1/mec15063_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149698/2/mec15063.pd

A Molecular Reexamination Of Introgression Between Helianthus Annuus And H. Bolanderi (Compositae)

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137464/1/evo04127.pd

Some perspective on Molecular Ecology perspectives: Are women being left out?

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149698/1/mec15063_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149698/2/mec15063.pd

Allele identification for transcriptome-based population genomics in the invasive plant Centaurea solstitialis

Transcriptome sequences are becoming more broadly available for multiple individuals of the same species, providing opportunities to derive population genomic information from these datasets. Using the 454 Life Science Genome Sequencer FLX and FLX-Titanium next-generation platforms, we generated 11−430 Mbp of sequence for normalized cDNA for 40 wild genotypes of the invasive plant Centaurea solstitialis, yellow starthistle, from across its worldwide distribution. We examined the impact of sequencing effort on transcriptome recovery and overlap among individuals. To do this, we developed two novel publicly available software pipelines: SnoWhite for read cleaning before assembly, and AllelePipe for clustering of loci and allele identification in assembled datasets with or without a reference genome. AllelePipe is designed specifically for cases in which read depth information is not appropriate or available to assist with disentangling closely related paralogs from allelic variation, as in transcriptome or previously assembled libraries. We find that modest applications of sequencing effort recover most of the novel sequences present in the transcriptome of this species, including single-copy loci and a representative distribution of functional groups. In contrast, the coverage of variable sites, observation of heterozygosity, and overlap among different libraries are all highly dependent on sequencing effort. Nevertheless, the information gained from overlapping regions was informative regarding coarse population structure and variation across our small number of population samples, providing the first genetic evidence in support of hypothesized invasion scenarios.Fil: Dlugosch, Katrina M.. University of British Columbia; CanadáFil: Lai, Zhao. Indiana University; Estados UnidosFil: Bonin, Auélie. Indiana University; Estados UnidosFil: Hierro, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Rieseberg, Loren H.. University of British Columbia; Canadá. Indiana University; Estados Unido

Functional androdioecy in the flowering plant Datisca glomerata

This scanned article is provided to correct an error on the publisher’s website. The online version has incorrectly given the first author name as “Listen, Aaron” rather than the correct, “Liston, Aaron.” If using this article, please cite the first author correctly

A target enrichment method for gathering phylogenetic information from hundreds of loci: An example from the Compositae.

UnlabelledPremise of the studyThe Compositae (Asteraceae) are a large and diverse family of plants, and the most comprehensive phylogeny to date is a meta-tree based on 10 chloroplast loci that has several major unresolved nodes. We describe the development of an approach that enables the rapid sequencing of large numbers of orthologous nuclear loci to facilitate efficient phylogenomic analyses. •Methods and resultsWe designed a set of sequence capture probes that target conserved orthologous sequences in the Compositae. We also developed a bioinformatic and phylogenetic workflow for processing and analyzing the resulting data. Application of our approach to 15 species from across the Compositae resulted in the production of phylogenetically informative sequence data from 763 loci and the successful reconstruction of known phylogenetic relationships across the family. •ConclusionsThese methods should be of great use to members of the broader Compositae community, and the general approach should also be of use to researchers studying other families

Parallel Ecological Speciation in Plants?

Populations that have independently evolved reproductive isolation from their ancestors while remaining reproductively cohesive have undergone parallel speciation. A specific type of parallel speciation, known as parallel ecological speciation, is one of several forms of evidence for ecology's role in speciation. In this paper we search the literature for candidate examples of parallel ecological speciation in plants. We use four explicit criteria (independence, isolation, compatibility, and selection) to judge the strength of evidence for each potential case. We find that evidence for parallel ecological speciation in plants is unexpectedly scarce, especially relative to the many well-characterized systems in animals. This does not imply that ecological speciation is uncommon in plants. It only implies that evidence from parallel ecological speciation is rare. Potential explanations for the lack of convincing examples include a lack of rigorous testing and the possibility that plants are less prone to parallel ecological speciation than animals