Effects of seasonal changes in cotton plants on the evolution of resistance to pyramided cotton producing the Bt toxins Cry1Ac and Cry1F in Helicoverpa zea

Yves Carriere, Ben A. Degain, Gopalan C. Unnithan, Virginia S. Harpold, Shannon Heuberger, Xianchun Li, Bruce E Tabashnik

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

BACKGROUND: In pests with inherently low susceptibility to Bacillus thuringiensis (Bt) toxins, seasonal declines in the concentration of Bt toxins in transgenic crops could accelerate evolution of resistance by increasing the dominance of resistance. Here, we evaluated Helicoverpa zea survival on young and old cotton plants that produced the Bt toxins Cry1Ac and Cry1F or did not produce Bt toxins. RESULTS: Using a strain selected for resistance to Cry1Ac in the laboratory, its parent strain that was not selected in the laboratory, and their F1 progeny, we showed that resistance to Cry1Ac + Cry1F cotton was partially dominant on young and old plants. On Cry1Ac + Cry1F cotton, redundant killing was incomplete on young plants but nearly complete on old plants. No significant fitness costs on non-Bt cotton occurred on young plants, but large recessive costs affected survival on old plants. Simulation models incorporating the empirical data showed that the seasonal changes in fitness could delay resistance to Cry1Ac + Cry1F cotton by inducing low equilibrium frequencies of resistance alleles when refuges are sufficiently large. CONCLUSION: Our results suggest that including effects of seasonal changes in fitness of pests on Bt crops and refuge plants can enhance resistance risk assessment and resistance management.

Original languageEnglish (US)
Pages (from-to)627-637
Number of pages11
JournalPest Management Science
Volume74
Issue number3
DOIs
StatePublished - Mar 1 2018

Fingerprint

Helicoverpa zea
Bacillus thuringiensis
toxins
cotton
pests
resistance management
crops
dominance (genetics)
risk assessment
simulation models
genetically modified organisms
alleles

Keywords

  • balanced polymorphism
  • fitness costs
  • incomplete resistance
  • redundant killing
  • resistance management

ASJC Scopus subject areas

  • Agronomy and Crop Science
  • Insect Science

Cite this

Effects of seasonal changes in cotton plants on the evolution of resistance to pyramided cotton producing the Bt toxins Cry1Ac and Cry1F in Helicoverpa zea. / Carriere, Yves; Degain, Ben A.; Unnithan, Gopalan C.; Harpold, Virginia S.; Heuberger, Shannon; Li, Xianchun; Tabashnik, Bruce E.

In: Pest Management Science, Vol. 74, No. 3, 01.03.2018, p. 627-637.

Research output: Contribution to journalArticle

@article{df751943f677418cb15f2935861cb887,
title = "Effects of seasonal changes in cotton plants on the evolution of resistance to pyramided cotton producing the Bt toxins Cry1Ac and Cry1F in Helicoverpa zea",
abstract = "BACKGROUND: In pests with inherently low susceptibility to Bacillus thuringiensis (Bt) toxins, seasonal declines in the concentration of Bt toxins in transgenic crops could accelerate evolution of resistance by increasing the dominance of resistance. Here, we evaluated Helicoverpa zea survival on young and old cotton plants that produced the Bt toxins Cry1Ac and Cry1F or did not produce Bt toxins. RESULTS: Using a strain selected for resistance to Cry1Ac in the laboratory, its parent strain that was not selected in the laboratory, and their F1 progeny, we showed that resistance to Cry1Ac + Cry1F cotton was partially dominant on young and old plants. On Cry1Ac + Cry1F cotton, redundant killing was incomplete on young plants but nearly complete on old plants. No significant fitness costs on non-Bt cotton occurred on young plants, but large recessive costs affected survival on old plants. Simulation models incorporating the empirical data showed that the seasonal changes in fitness could delay resistance to Cry1Ac + Cry1F cotton by inducing low equilibrium frequencies of resistance alleles when refuges are sufficiently large. CONCLUSION: Our results suggest that including effects of seasonal changes in fitness of pests on Bt crops and refuge plants can enhance resistance risk assessment and resistance management.",
keywords = "balanced polymorphism, fitness costs, incomplete resistance, redundant killing, resistance management",
author = "Yves Carriere and Degain, {Ben A.} and Unnithan, {Gopalan C.} and Harpold, {Virginia S.} and Shannon Heuberger and Xianchun Li and Tabashnik, {Bruce E}",
year = "2018",
month = "3",
day = "1",
doi = "10.1002/ps.4746",
language = "English (US)",
volume = "74",
pages = "627--637",
journal = "Pest Management Science",
issn = "1526-498X",
publisher = "John Wiley and Sons Ltd",
number = "3",

}

TY - JOUR

T1 - Effects of seasonal changes in cotton plants on the evolution of resistance to pyramided cotton producing the Bt toxins Cry1Ac and Cry1F in Helicoverpa zea

AU - Carriere, Yves

AU - Degain, Ben A.

AU - Unnithan, Gopalan C.

AU - Harpold, Virginia S.

AU - Heuberger, Shannon

AU - Li, Xianchun

AU - Tabashnik, Bruce E

PY - 2018/3/1

Y1 - 2018/3/1

N2 - BACKGROUND: In pests with inherently low susceptibility to Bacillus thuringiensis (Bt) toxins, seasonal declines in the concentration of Bt toxins in transgenic crops could accelerate evolution of resistance by increasing the dominance of resistance. Here, we evaluated Helicoverpa zea survival on young and old cotton plants that produced the Bt toxins Cry1Ac and Cry1F or did not produce Bt toxins. RESULTS: Using a strain selected for resistance to Cry1Ac in the laboratory, its parent strain that was not selected in the laboratory, and their F1 progeny, we showed that resistance to Cry1Ac + Cry1F cotton was partially dominant on young and old plants. On Cry1Ac + Cry1F cotton, redundant killing was incomplete on young plants but nearly complete on old plants. No significant fitness costs on non-Bt cotton occurred on young plants, but large recessive costs affected survival on old plants. Simulation models incorporating the empirical data showed that the seasonal changes in fitness could delay resistance to Cry1Ac + Cry1F cotton by inducing low equilibrium frequencies of resistance alleles when refuges are sufficiently large. CONCLUSION: Our results suggest that including effects of seasonal changes in fitness of pests on Bt crops and refuge plants can enhance resistance risk assessment and resistance management.

AB - BACKGROUND: In pests with inherently low susceptibility to Bacillus thuringiensis (Bt) toxins, seasonal declines in the concentration of Bt toxins in transgenic crops could accelerate evolution of resistance by increasing the dominance of resistance. Here, we evaluated Helicoverpa zea survival on young and old cotton plants that produced the Bt toxins Cry1Ac and Cry1F or did not produce Bt toxins. RESULTS: Using a strain selected for resistance to Cry1Ac in the laboratory, its parent strain that was not selected in the laboratory, and their F1 progeny, we showed that resistance to Cry1Ac + Cry1F cotton was partially dominant on young and old plants. On Cry1Ac + Cry1F cotton, redundant killing was incomplete on young plants but nearly complete on old plants. No significant fitness costs on non-Bt cotton occurred on young plants, but large recessive costs affected survival on old plants. Simulation models incorporating the empirical data showed that the seasonal changes in fitness could delay resistance to Cry1Ac + Cry1F cotton by inducing low equilibrium frequencies of resistance alleles when refuges are sufficiently large. CONCLUSION: Our results suggest that including effects of seasonal changes in fitness of pests on Bt crops and refuge plants can enhance resistance risk assessment and resistance management.

KW - balanced polymorphism

KW - fitness costs

KW - incomplete resistance

KW - redundant killing

KW - resistance management

UR - http://www.scopus.com/inward/record.url?scp=85041345903&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85041345903&partnerID=8YFLogxK

U2 - 10.1002/ps.4746

DO - 10.1002/ps.4746

M3 - Article

C2 - 28967711

AN - SCOPUS:85041345903

VL - 74

SP - 627

EP - 637

JO - Pest Management Science

JF - Pest Management Science

SN - 1526-498X

IS - 3

ER -