Functional synergy and genomic linkage of glyphosate resistance traits in Canada fleabane.

Background: Glyphosate resistance in Conyza canadensis (Canada fleabane) has been primarily attributed to non-target-site resistance (NTSR) mechanisms such as vacuolar sequestration, though these have not been formally elucidated. While a target-site mutation at EPSPS2 (P106S) was recently identified, it failed to account for many resistant cases. These findings underscore the need to re-evaluate the genetic basis of glyphosate resistance in this species.

Global biodiversity data suggest allopolyploid plants do not occupy larger ranges or harsher conditions compared with their progenitors.

Understanding the factors determining species' geographical and environmental range is a central question in evolution and ecology, and key for developing conservation and management practices. Shortly after the discovery of polyploidy, just over 100 years ago, it was suggested that polyploids generally have greater range sizes and occur in more extreme conditions than their diploid congeners. This suggestion is now widely accepted in the literature and is attributed to polyploids having an increased capacity for genetic diversity that increases their potential for adaptation and invasiveness.

Insights from the genomes of 4 diploid Camelina spp.

Plant evolution has been a complex process involving hybridization and polyploidization making understanding the origin and evolution of a plant's genome challenging even once a published genome is available. The oilseed crop, Camelina sativa (Brassicaceae), has a fully sequenced allohexaploid genome with 3 unknown ancestors. To better understand which extant species best represent the ancestral genomes that contributed to C.

Update on the Brassicaceae species checklist.

Background: Here we present a revised species checklist for the Brassicaceae, updated from Warwick SI, Francis, A, Al-Shehbaz IA (2006), Brassicaceae: Species checklist and database on CD-ROM, Plant Systematics and Evolution 259: 249─25. This update of the checklist was initiated, based on recent taxonomic and molecular studies on the Brassicaceae that have resulted in new species names, combinations and associated synonyms.

New Information: New data have been added indicating tribal affiliations within the family and where type specimens have been designated.

High gene flow maintains genetic diversity following selection for high EPSPS copy number in the weed kochia (Amaranthaceae).

Kochia, a major weed species, has evolved resistance to four herbicide modes of action. Herbicide resistance appears to spread quickly, which could result in diminished standing genetic variation, reducing the ability of populations to adapt further. Here we used double digest restriction enzyme associated sequencing to determine the level of gene flow among kochia populations and whether selection for glyphosate resistance reduces genetic variation.

A chromosome-scale draft sequence of the Canada fleabane genome.

Background: Due to the accessibility of underlying technologies the 'Omics', in particular genomics, are becoming commonplace in several fields of research, including the study of agricultural pests. The weed community is starting to embrace these approaches; genome sequences have been made available in the past years, with several other sequencing projects underway, as promoted by the International Weed Genome Consortium. Chromosome-scale sequences are essential to fully exploit the power of genetics and genomics.

Population Genomic Approaches for Weed Science.

Genomic approaches are opening avenues for understanding all aspects of biological life, especially as they begin to be applied to multiple individuals and populations. However, these approaches typically depend on the availability of a sequenced genome for the species of interest. While the number of genomes being sequenced is exploding, one group that has lagged behind are weeds.

Polyploidization for the Genetic Improvement of .

is a diploid species, cultivated throughout the ages as a source of fiber, food, and secondary metabolites with therapeutic and recreational properties. Polyploidization is considered as a valuable tool in the genetic improvement of crop plants. Although this method has been used in hemp-type Cannabis, it has never been applied to drug-type strains.

Hybridization rate and hybrid fitness for Andrz. ex DC (♀) and (L.) Crantz(Brassicaceae) (♂).

Hybridization between crops and their wild relatives has the potential to introduce novel variation into wild populations. Camelina () is a promising oilseed and cultivars with modified seed characteristics and herbicide resistance are in development, prompting a need to evaluate the potential for novel trait introgression into weedy relatives. Little-podded false flax (littlepod) is a naturalized weed in Canada and the USA.

Assessment of Antinutritional Compounds and Chemotaxonomic Relationships between Camelina sativa and Its Wild Relatives.

We compared the secondary metabolite composition in seeds of Camelina sativa and its wild relatives to identify potential germplasm with reduced levels of antinutritional compounds. Twenty Camelina accessions, from five different species, were analyzed by liquid chromatography mass spectrometry and subjected to principal component analysis, which revealed that Camelina spp. separated into distinct chemotaxonomic groups.

flowPloidy: An R package for genome size and ploidy assessment of flow cytometry data.

Premise Of The Study: Despite advantages in terms of reproducibility, histogram analysis based on nonlinear regression is rarely used in genome size assessments in plant biology. This is due in part to the lack of a freely available program to implement the procedure. We have developed such a program, the R package flowPloidy.

Glyphosate resistance reduces kochia fitness: Comparison of segregating resistant and susceptible F2 populations.

Glyphosate is considered the world's most important herbicide, but widespread and continual use has resulted in the evolution of resistance. Kochia scoparia (kochia) has evolved resistance via tandem gene amplification of glyphosate's target, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) and resistant populations have been reported from the Canadian Prairies and the Northern Great Plains. Here, we evaluated the fitness costs of EPSPS amplification in kochia by comparing susceptible and resistant full siblings from segregating F2 populations generated from within six populations.

Bidirectional but asymmetrical sexual hybridization between Brassica carinata and Sinapis arvensis (Brassicaceae).

With transgenic crop development it is important to evaluate the potential for transgenes to escape into populations of wild, weedy relatives. Ethiopian mustard (Brassica carinata, BBCC) is easily transformed and is being investigated for uses from biodiesel fuels to biopharmaceuticals. However, little work has been done evaluating its ability to cross with relatives such as wild mustard (Sinapsis arvensis, SrSr), an abundant, cosmopolitan weedy relative.

Synoptic weather typing applied to air pollution mortality among the elderly in 10 Canadian cities.

Background: Synoptic circulation patterns (large-scale weather systems) affect ambient levels of air pollution, as well as the relationship between air pollution and human health.

Objective: To investigate the air pollution-mortality relationship within weather types and seasons, and to determine which combination of atmospheric conditions may pose increased health threats in the elderly age categories.

Methods: The relative risk of mortality (RR) due to air pollution was examined using Poisson generalized linear models (GLMs) within specific weather types.

Adaptation of diploid and tetraploid chamerion angustifolium to elevation but not local environment.

Polyploid organisms often have different geographic ranges than their diploid relatives. However, it is unclear whether this divergence is maintained by adaptation or results from historical differences in colonization. Here, we conducted a reciprocal transplant experiment with diploid and autotetraploid Chamerion angustifolium to test for adaptation at the ploidy and population level.

Whole genome duplication affects evolvability of flowering time in an autotetraploid plant.

Whole genome duplications have occurred recurrently throughout the evolutionary history of eukaryotes. The resulting genetic and phenotypic changes can influence physiological and ecological responses to the environment; however, the impact of genome copy number on evolvability has rarely been examined experimentally. Here, we evaluate the effect of genome duplication on the ability to respond to selection for early flowering time in lines drawn from naturally occurring diploid and autotetraploid populations of the plant Chamerion angustifolium (fireweed).

Climate change and future temperature-related mortality in 15 Canadian cities.

The environmental changes caused by climate change represent a significant challenge to human societies. One part of this challenge will be greater heat-related mortality. Populations in the northern hemisphere will experience temperature increases exceeding the global average, but whether this will increase or decrease total temperature-related mortality burdens is debated.

Design, fabrication and demonstration of a magnetophoresis chamber with 25 output fractions.

Our goal is to develop an instrument for parallel and multiplexed bioassay using magnetic labels. Toward this end we are developing a multi-outlet magnetophoresis instrument incorporating a fluidic flow chamber placed inside a magnetic field gradient. Magnetic microparticles are sorted by their magnetic moment for eventual use as biological labels based on magnetic signature.