A5077249592- Genetic diversity and population structure
- Plant and animal studies
- Genetic Mapping and Diversity in Plants and Animals
- Genetic and phenotypic traits in livestock
- Ecology and Vegetation Dynamics Studies
- Evolution and Genetic Dynamics
- Plant Reproductive Biology
- Forest Insect Ecology and Management
- Wheat and Barley Genetics and Pathology
- Plant biochemistry and biosynthesis
- Animal Behavior and Reproduction
- Chromosomal and Genetic Variations
- Insect-Plant Interactions and Control
- Genetics and Plant Breeding
- Tree-ring climate responses
- Species Distribution and Climate Change
- Plant Water Relations and Carbon Dynamics
- Statistical Methods and Inference
- Molecular Biology Techniques and Applications
- Plant pathogens and resistance mechanisms
- Plant Taxonomy and Phylogenetics
- Ecology and biodiversity studies
- Statistical Distribution Estimation and Applications
- Turfgrass Adaptation and Management
- Yeasts and Rust Fungi Studies
Dalhousie University
2007-2022
University of Colorado Boulder
1993-2001
University of Toronto
1993-1994
McGill University
1989
We examined genetic differentiation among seven populations of limber pine using four classes gene marker. Among-population was much higher for maternally inherited mitochondrial DNA polymorphisms than paternally chloroplast DNA, indicating that wind-dispersed pollen is the main agent flow. Chloroplast consistent with flow estimated in a prior paternity analysis. Using estimates seed and derived from mtDNA cpDNA differentiation, we predicted value Fst expected at nuclear loci. Allelic...
Hybridization is an important factor in the evolution of plants; however, many studies that have examined hybrid fitness been concerned with study early generation hybrids. We early‐ and late‐generation consequences hybridization between two ecotypes selfing annual Avena barbata a greenhouse environment as well natural environments. Fitness (F2) hybrids reflects both action dominance effects (hybrid vigor) recombination breakdown) was not significantly different from midparent any...
We constructed recombinant inbred lines of a cross between naturally occurring ecotypes Avena barbata (Pott ex Link), Poaceae, associated with contrasting moisture environments. These were assessed for fitness in common garden reciprocal transplant experiments two field sites each years, as well novel, benign greenhouse environment. An AFLP (amplified fragment length polymorphism) linkage map 129 markers spanned 644 cM 19 groups, which is smaller, more than expected. Therefore parts the A....
Genome analysis of 27 oat species identifies ancestral groups, delineates the D genome, and origin 21 mapped chromosomes in hexaploid oat. We investigated genomic relationships among genus Avena using high-density genetic markers revealed by genotyping-by-sequencing (GBS). Two methods GBS were used: one based on tag-level haplotypes that previously cultivated (A. sativa), intended to sample enumerate originating from all under investigation. Qualitatively, both gave similar predictions...
I examined the effects of historical division and secondary contact between eastern western varieties ponderosa pine (Pinus Laws Pinaceae) on extant patterns genetic variation. Fossil biogeographic evidence both indicate that current point these two represents following separation during Wisconsin glaciation. Current gene flow was assessed by observing degree introgression paternally inherited cpDNA maternally mtDNA polymorphisms. Both seeds pollen are wind dispersed in pine. Introgression...
We examined the spatial distribution of maternally inherited mitochondrial DNA and paternally chloroplast polymorphisms in a permanently marked stand ponderosa pine (Pinus Laws). Movement mtDNA occurs only via seed dispersal, haplotypes showed significant patch structure. Moreover, individuals within patches identified by were related approximately as half-sibs based upon analysis allozyme genotypes. Thus, dispersal is limited population, creates matrilineal clusters space. By contrast,...
Abstract To make inferences about the glacial refugia that harboured limber pine, Pinus flexilis James, we examined range‐wide population structure of mitochondrial DNA (mtDNA) with eight size variants in second intron nad1 . The data consisted haplotypes from 704 trees collected 40 localities. value F ST for these populations was 0.80, which is a much larger than has been reported allozymes and chloroplast (cpDNA) it suggests number seeds moving among localities per generation ≈ 0.12. Gene...
Genome size is an indicator of evolutionary distance and a metric for genome characterization. Here, we report accurate estimates in 99 accessions from 26 species Avena. We demonstrate that the average C diploid (2C = 10.26 pg) 15% larger than A 8.95 pg), this difference likely accounts progression among tetraploid species, where AB < AC CC (average 2C 16.76, 18.60, 21.78 pg, respectively). All three hexaploid with ACD configuration had similar sizes 25.74 pg). was mostly consistent within...
Summary Many recent studies have sought to identify targets of diversifying selection by testing the neutral expectation that all loci will show similar levels population divergence ( F st ). Contrasts between quantitative traits Q ) and molecular markers suggest typically diverge in response local pressures more than do individual genes. Coalescence theory makes it possible simulate distribution expected under neutrality for many situations, including nonequilibrium conditions. Such...
When recessive mutations are the primary cause of inbreeding depression, a negative relationship between levels prior and depression is expected. We tested this prediction using 15 populations chosen priori to represent wide range among four closely related taxa Mimulus guttatus species complex. Artificially selfed outcrossed progeny were grown under controlled growth-chamber conditions, was estimated for each population as one minus ratio fitness progeny. Estimates varied from 0% 68%...
Abstract Maternally inherited mtDNA in a secondary contact zone of ponderosa pine revealed cline less than 10 km wide — much narrower previously described. A survey 76 populations gave no evidence either intermixing or mosaic zone. Such sharp zones are consistent with diffusive range expansion, rather long distance colonization. However, for seed dispersal events was found two where haplotypes were observed far from their main area occurrence. The results suggest small number colonists these centres.
• Comparative studies suggest that a positive correlation between xylem water transport and photosynthesis is adaptive. A requirement for the adaptive evolution of coordination photosynthetic functions presence genetic variation covariation these traits within populations. Here it was determined whether there leaf blade hydraulic conductivity (KW), rate (A), stomatal conductance (gs), time to flowering in population recombinant inbred lines Avena barbata, Mediterranean annual grass....
Abstract Conservation genetics can be seen as the effort to influence evolutionary process in ways that enhance persistence of populations. Much published research field applies genetic sampling techniques infer population parameters from patterns variation threatened The limited resolution these inferences seems yield confidence which results conservative policy recommendations. As an alternative, I suggest conservation focus on relationships between those variables conservationists...
Environmental stress can alter genetic variation and covariation underlying functional traits, thus affect adaptive evolution in response to natural selection. However, the basis of traits is rarely examined contrasting resource environments, consequently, there no consensus regarding whether environmental constrains or facilitates evolution. We tested availability affects for among seven physiological morphological/performance by growing annual grass Avena barbata dry well-watered...
Forty years ago, Robert Allard and colleagues documented that the slender wild oat, Avena barbata, occurred in California as two multi-locus allozyme genotypes, associated with mesic xeric habitats. This is arguably first example of ecotypes identified by molecular techniques. Despite widespread citation, however, inference local adaptation these rested primarily on pattern. study tests for using reciprocal transplant quantitative trait locus (QTL) mapping Both 188 recombinant inbred lines...
Abstract The genus Avena (oats) contains diploid, tetraploid and hexaploid species that evolved through hybridization polyploidization. Four genome types (named A D) are generally recognized. We used GBS markers to construct linkage maps of diploid ( strigosa x . wiestii , 2n = 14), AB barbata 28) oats. These greatly improve coverage from older marker systems. Seven groups in the showed much stronger homology synteny with diploids than did other seven, implying an allopolyploid hybrid origin...
Abstract We measured the cytonuclear disequilibrium between 11 nuclear allozyme loci and both mitochondrial chloroplast DNA haplotypes in a natural population of ponderosa pine (Pinus ponderosa, Laws). Three showed significant associations with mtDNA variation, while two other association cpDNA. However, absolute number individuals involved any was small, such that none nuclear-organellar combinations difference observed expected numbers &gt;11 individuals. Patterns were not consistent...