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Occurrence of an herbicide-resistant plant trait in agricultural field margins.

Gage KL, Gibson DJ, Young BG, Young JM, Matthews JL, Weller SC, Wilson RG - Ecol Evol (2015)

Bottom Line: We found that geographic location was an important factor in the occurrence of GR C. canadensis in field margins.Although not consistently associated with either glyphosate resistance or glyphosate susceptibility, there were differences in phenology, survivorship, and herbivory among biotypes of C. canadensis.We found equal or greater fitness in GR biotypes, compared to GS biotypes, and GR plants were present in field margins.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant, Soil, and Agricultural Systems Southern Illinois University Carbondale Illinois 62901 ; Department of Plant Biology Center for Ecology Southern Illinois University Carbondale Illinois 06460.

ABSTRACT
Agricultural environments allow study of evolutionary change in plants. An example of evolution within agroecological systems is the selection for resistance to the herbicide glyphosate within the weed, Conyza canadensis. Changes in survivorship and reproduction associated with the development of glyphosate resistance (GR) may impact fitness and influence the frequency of occurrence of the GR trait. We hypothesized that site characteristics and history would affect the occurrence of GR C. canadensis in field margins. We surveyed GR occurrence in field margins and asked whether there were correlations between GR occurrence and location, crop rotation, GR crop trait rotation, crop type, use of tillage, and the diversity of herbicides used. In a field experiment, we hypothesized that there would be no difference in fitness between GR and glyphosate-susceptible (GS) plants. We asked whether there were differences in survivorship, phenology, reproduction, and herbivory between 2 GR and 2 GS populations of C. canadensis in agrestal and ruderal habitats. We found that geographic location was an important factor in the occurrence of GR C. canadensis in field margins. Although not consistently associated with either glyphosate resistance or glyphosate susceptibility, there were differences in phenology, survivorship, and herbivory among biotypes of C. canadensis. We found equal or greater fitness in GR biotypes, compared to GS biotypes, and GR plants were present in field margins. Field margins or ruderal habitats may provide refugia for GR C. canadensis, allowing reproduction and further selection to occur as seeds recolonize the agrestal habitat. Agricultural practices may select for ecological changes that feed back into the evolution of plants in ruderal habitats.

No MeSH data available.


Related in: MedlinePlus

Map of field margins indicating sites of seed collection, labeled by percentage of GR C. canadensis plants collected.
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ece31667-fig-0001: Map of field margins indicating sites of seed collection, labeled by percentage of GR C. canadensis plants collected.

Mentions: Seeds were collected from Benchmark Study field margins at 17 sites in three US states in order to examine the occurrence of the GR trait and the relationship to the selection pressures in field interiors (Fig. 1). These sites were chosen based upon 2006 field survey data that showed the presence of C. canadensis in field interiors. Seeds were collected from up to 11 plants in field margins which had not been exposed to herbicide spray or drift (Table S1). Seeds from each plant were kept separate so that the inference of GR status could be made for individuals through tests of their progeny. In order to assign a biologically meaningful variable to geographic location, field sites were identified by USDA plant hardiness zone (Cathey 1990). USDA plant hardiness zones reflect the average minimum frost‐free days for a given location and are therefore a direct measure of temperature tolerances for plant distributions that may affect the occurrence of resistance.


Occurrence of an herbicide-resistant plant trait in agricultural field margins.

Gage KL, Gibson DJ, Young BG, Young JM, Matthews JL, Weller SC, Wilson RG - Ecol Evol (2015)

Map of field margins indicating sites of seed collection, labeled by percentage of GR C. canadensis plants collected.
© Copyright Policy - creativeCommonsBy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4588657&req=5

ece31667-fig-0001: Map of field margins indicating sites of seed collection, labeled by percentage of GR C. canadensis plants collected.
Mentions: Seeds were collected from Benchmark Study field margins at 17 sites in three US states in order to examine the occurrence of the GR trait and the relationship to the selection pressures in field interiors (Fig. 1). These sites were chosen based upon 2006 field survey data that showed the presence of C. canadensis in field interiors. Seeds were collected from up to 11 plants in field margins which had not been exposed to herbicide spray or drift (Table S1). Seeds from each plant were kept separate so that the inference of GR status could be made for individuals through tests of their progeny. In order to assign a biologically meaningful variable to geographic location, field sites were identified by USDA plant hardiness zone (Cathey 1990). USDA plant hardiness zones reflect the average minimum frost‐free days for a given location and are therefore a direct measure of temperature tolerances for plant distributions that may affect the occurrence of resistance.

Bottom Line: We found that geographic location was an important factor in the occurrence of GR C. canadensis in field margins.Although not consistently associated with either glyphosate resistance or glyphosate susceptibility, there were differences in phenology, survivorship, and herbivory among biotypes of C. canadensis.We found equal or greater fitness in GR biotypes, compared to GS biotypes, and GR plants were present in field margins.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant, Soil, and Agricultural Systems Southern Illinois University Carbondale Illinois 62901 ; Department of Plant Biology Center for Ecology Southern Illinois University Carbondale Illinois 06460.

ABSTRACT
Agricultural environments allow study of evolutionary change in plants. An example of evolution within agroecological systems is the selection for resistance to the herbicide glyphosate within the weed, Conyza canadensis. Changes in survivorship and reproduction associated with the development of glyphosate resistance (GR) may impact fitness and influence the frequency of occurrence of the GR trait. We hypothesized that site characteristics and history would affect the occurrence of GR C. canadensis in field margins. We surveyed GR occurrence in field margins and asked whether there were correlations between GR occurrence and location, crop rotation, GR crop trait rotation, crop type, use of tillage, and the diversity of herbicides used. In a field experiment, we hypothesized that there would be no difference in fitness between GR and glyphosate-susceptible (GS) plants. We asked whether there were differences in survivorship, phenology, reproduction, and herbivory between 2 GR and 2 GS populations of C. canadensis in agrestal and ruderal habitats. We found that geographic location was an important factor in the occurrence of GR C. canadensis in field margins. Although not consistently associated with either glyphosate resistance or glyphosate susceptibility, there were differences in phenology, survivorship, and herbivory among biotypes of C. canadensis. We found equal or greater fitness in GR biotypes, compared to GS biotypes, and GR plants were present in field margins. Field margins or ruderal habitats may provide refugia for GR C. canadensis, allowing reproduction and further selection to occur as seeds recolonize the agrestal habitat. Agricultural practices may select for ecological changes that feed back into the evolution of plants in ruderal habitats.

No MeSH data available.


Related in: MedlinePlus