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Evolution of Herbicide Resistance in Lolium perenne ssp. multiflorum Populations.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Evolution of Herbicide Resistance in Lolium perenne ssp. multiflorum Populations./
Author:	Karn, Elizabeth Vivian.
Description:	1 online resource (109 pages)
Notes:	Source: Dissertation Abstracts International, Volume: 78-10(E), Section: B.
Contained By:	Dissertation Abstracts International78-10B(E).
Subject:	Plant sciences. -
Online resource:	click for full text (PQDT)
ISBN:	9781369795646

Evolution of Herbicide Resistance in Lolium perenne ssp. multiflorum Populations.
Karn, Elizabeth Vivian.

Evolution of Herbicide Resistance in Lolium perenne ssp. multiflorum Populations. - 1 online resource (109 pages)

Source: Dissertation Abstracts International, Volume: 78-10(E), Section: B.

Thesis (Ph.D.)--University of California, Davis, 2017.

Includes bibliographical references

Herbicide-resistant weeds provide a unique system in which to study the evolution of adaptive traits. The selection pressures, adaptive traits, and often the underlying basis for herbicide resistance are typically known, allowing for studies of adaptive variation across large agricultural landscapes that vary in selection pressures and intensities over space and time. In the last several years, populations of Lolium perenne ssp. multiflorum (Lam.) in orchards and vineyards of northwest California were suspected of evolving resistance to the herbicides glyphosate and glufosinate. Earlier work identified that a non-synonymous mutation in 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene is responsible for glyphosate resistance in the Central Valley of California. The research presented in this dissertation characterizes phenotypes resistant to glyphosate and glufosinate and examines the evolution of glyphosate resistance in northwest California populations of L. perenne ssp. multiflorum using neutral genetic diversity and adaptive genetic variation, to gain a greater understanding of contemporary adaptive evolution across landscapes.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2018

Mode of access: World Wide Web

ISBN: 9781369795646Subjects--Topical Terms:

1179743
Plant sciences.
Index Terms--Genre/Form:

554714
Electronic books.

Evolution of Herbicide Resistance in Lolium perenne ssp. multiflorum Populations.
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245 1 0 $a Evolution of Herbicide Resistance in Lolium perenne ssp. multiflorum Populations.
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300 $a 1 online resource (109 pages)
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500 $a Source: Dissertation Abstracts International, Volume: 78-10(E), Section: B.
500 $a Adviser: Marie A. Jasieniuk.
502 $a Thesis (Ph.D.)--University of California, Davis, 2017.
504 $a Includes bibliographical references
520 $a Herbicide-resistant weeds provide a unique system in which to study the evolution of adaptive traits. The selection pressures, adaptive traits, and often the underlying basis for herbicide resistance are typically known, allowing for studies of adaptive variation across large agricultural landscapes that vary in selection pressures and intensities over space and time. In the last several years, populations of Lolium perenne ssp. multiflorum (Lam.) in orchards and vineyards of northwest California were suspected of evolving resistance to the herbicides glyphosate and glufosinate. Earlier work identified that a non-synonymous mutation in 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene is responsible for glyphosate resistance in the Central Valley of California. The research presented in this dissertation characterizes phenotypes resistant to glyphosate and glufosinate and examines the evolution of glyphosate resistance in northwest California populations of L. perenne ssp. multiflorum using neutral genetic diversity and adaptive genetic variation, to gain a greater understanding of contemporary adaptive evolution across landscapes.
520 $a In Chapter 1, I measure the frequency of glyphosate-resistant and glufosinate-resistant individuals in 14 populations of L. perenne across three screening times and measure the population-average level of resistance in selected populations. The analysis demonstrates that while both glyphosate- and glufosinate-resistant individuals are present in northwest California with distinct mechanisms conferring resistance to each herbicide, these resistance phenotypes are variable over time, especially for glufosinate. In Chapter 2, using microsatellite genetic variation at 12 loci in the sampled individuals, I show that California L. perenne contains high genetic diversity and admixture across populations, with a potential for spread of glyphosate resistance through gene flow. In Chapter 3, I genotype adaptive genetic variation in the sampled individuals and identified four distinct glyphosate-resistant EPSPS alleles at codon site 106, indicating multiple evolutionary origins of glyphosate resistance in the region, although resistance in some populations cannot be explained by EPSPS mutations at site 106. Together, these results demonstrate that the evolution of adaptive traits across a landscape can be quite complex, with variable phenotypes conferred by multiple independent evolutionary origins of the same adaptive trait with subsequent spread through gene flow.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2018
538 $a Mode of access: World Wide Web
650 4 $a Plant sciences. $3 1179743
655 7 $a Electronic books. $2 local $3 554714
690 $a 0479
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a University of California, Davis. $b Plant Biology. $3 1190574
773 0 $t Dissertation Abstracts International $g 78-10B(E).
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=10251329 $z click for full text (PQDT)