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The geographic mosaic of herbicide resistance evolution in the common morning glory, Ipomoea purpurea: Evidence for resistance hotspots and low genetic differentiation across the landscape.

Kuester A, Chang SM, Baucom RS - Evol Appl (2015)

Bottom Line: We uncovered a mosaic pattern of resistance across the landscape, with some populations exhibiting high-survival postherbicide and other populations showing high death.SSR genotyping revealed little evidence of isolation by distance and very little neutral genetic structure associated with geography.An approximate Bayesian computation (ABC) analysis uncovered evidence for migration and admixture among populations before the widespread use of glyphosate rather than the very recent contemporary gene flow.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology and Evolutionary Biology, 830 North University, University of Michigan Ann Arbor, MI, USA.

ABSTRACT
Strong human-mediated selection via herbicide application in agroecosystems has repeatedly led to the evolution of resistance in weedy plants. Although resistance can occur among separate populations of a species across the landscape, the spatial scale of resistance in many weeds is often left unexamined. We assessed the potential that resistance to the herbicide glyphosate in the agricultural weed Ipomoea purpurea has evolved independently multiple times across its North American range. We examined both adaptive and neutral genetic variations in 44 populations of I. purpurea by pairing a replicated dose-response greenhouse experiment with SSR genotyping of experimental individuals. We uncovered a mosaic pattern of resistance across the landscape, with some populations exhibiting high-survival postherbicide and other populations showing high death. SSR genotyping revealed little evidence of isolation by distance and very little neutral genetic structure associated with geography. An approximate Bayesian computation (ABC) analysis uncovered evidence for migration and admixture among populations before the widespread use of glyphosate rather than the very recent contemporary gene flow. The pattern of adaptive and neutral genetic variations indicates that resistance in this mixed-mating weed species appears to have evolved in independent hotspots rather than through transmission of resistance alleles across the landscape.

No MeSH data available.


Related in: MedlinePlus

STRUCTURE assignment of individuals to genetic clusters. Small bars represent the assignment of individuals to clusters, with sampling locations differentiated by thick black lines for 35 populations sampled. Shown are each population denoted by State: IN = Indiana, OH = Ohio, NC = North Carolina, SC = South Carolina, TN = Tennessee, VA = Virginia, and population ID number.
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fig05: STRUCTURE assignment of individuals to genetic clusters. Small bars represent the assignment of individuals to clusters, with sampling locations differentiated by thick black lines for 35 populations sampled. Shown are each population denoted by State: IN = Indiana, OH = Ohio, NC = North Carolina, SC = South Carolina, TN = Tennessee, VA = Virginia, and population ID number.

Mentions: Further, although we found a moderate level of genetic differentiation across populations sampled from North America, our STRUCTURE analysis uncovered a pattern of widespread migration and admixture among individuals within populations (Fig. 5). The most likely number of genetic clusters within the sampled range for I. purpurea was k = 3 (ln(P(D) = −8265.7). All 3 genotypic clusters were found within individuals sampled from North Carolina suggesting that populations within this state are either the source of introduction for other weedy populations or this state has had multiple introductions of different seed lots.


The geographic mosaic of herbicide resistance evolution in the common morning glory, Ipomoea purpurea: Evidence for resistance hotspots and low genetic differentiation across the landscape.

Kuester A, Chang SM, Baucom RS - Evol Appl (2015)

STRUCTURE assignment of individuals to genetic clusters. Small bars represent the assignment of individuals to clusters, with sampling locations differentiated by thick black lines for 35 populations sampled. Shown are each population denoted by State: IN = Indiana, OH = Ohio, NC = North Carolina, SC = South Carolina, TN = Tennessee, VA = Virginia, and population ID number.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4561571&req=5

fig05: STRUCTURE assignment of individuals to genetic clusters. Small bars represent the assignment of individuals to clusters, with sampling locations differentiated by thick black lines for 35 populations sampled. Shown are each population denoted by State: IN = Indiana, OH = Ohio, NC = North Carolina, SC = South Carolina, TN = Tennessee, VA = Virginia, and population ID number.
Mentions: Further, although we found a moderate level of genetic differentiation across populations sampled from North America, our STRUCTURE analysis uncovered a pattern of widespread migration and admixture among individuals within populations (Fig. 5). The most likely number of genetic clusters within the sampled range for I. purpurea was k = 3 (ln(P(D) = −8265.7). All 3 genotypic clusters were found within individuals sampled from North Carolina suggesting that populations within this state are either the source of introduction for other weedy populations or this state has had multiple introductions of different seed lots.

Bottom Line: We uncovered a mosaic pattern of resistance across the landscape, with some populations exhibiting high-survival postherbicide and other populations showing high death.SSR genotyping revealed little evidence of isolation by distance and very little neutral genetic structure associated with geography.An approximate Bayesian computation (ABC) analysis uncovered evidence for migration and admixture among populations before the widespread use of glyphosate rather than the very recent contemporary gene flow.

View Article: PubMed Central - PubMed

Affiliation: Department of Ecology and Evolutionary Biology, 830 North University, University of Michigan Ann Arbor, MI, USA.

ABSTRACT
Strong human-mediated selection via herbicide application in agroecosystems has repeatedly led to the evolution of resistance in weedy plants. Although resistance can occur among separate populations of a species across the landscape, the spatial scale of resistance in many weeds is often left unexamined. We assessed the potential that resistance to the herbicide glyphosate in the agricultural weed Ipomoea purpurea has evolved independently multiple times across its North American range. We examined both adaptive and neutral genetic variations in 44 populations of I. purpurea by pairing a replicated dose-response greenhouse experiment with SSR genotyping of experimental individuals. We uncovered a mosaic pattern of resistance across the landscape, with some populations exhibiting high-survival postherbicide and other populations showing high death. SSR genotyping revealed little evidence of isolation by distance and very little neutral genetic structure associated with geography. An approximate Bayesian computation (ABC) analysis uncovered evidence for migration and admixture among populations before the widespread use of glyphosate rather than the very recent contemporary gene flow. The pattern of adaptive and neutral genetic variations indicates that resistance in this mixed-mating weed species appears to have evolved in independent hotspots rather than through transmission of resistance alleles across the landscape.

No MeSH data available.


Related in: MedlinePlus