Abstract
The efficacy of nontransgenic sweet corn, Zea mays L., hybrids cross-pollinated by Bacillus thuringiensis (Bt) sweet corn hybrids expressing Cry1Ab toxin was evaluated in both field and laboratory studies in Minnesota in 2000. Non-Bt and Bt hybrids (maternal plants) were cross-pollinated with pollen from both non-Bt and Bt hybrids (paternal plants) to create four crosses. Subsequent crosses were evaluated for efficacy in the field against European corn borer, Ostrinia nubilalis (Hübner), and corn earworm, Helicoverpa zea (Boddie), and in laboratory bioassays against O. nubilalis. Field studies indicated that crosses with maternal Bt plants led to low levels of survival for both O. nubilalis and H. zea compared with the non-Bt x non-Bt cross. However, the cross between non-Bt ears and Bt pollen led to survival rates of 43 and 63% for O. nubilalis and H. zea larvae, respectively. This intermediate level of survival also was reflected in the number of kernels damaged. Laboratory bioassays for O. nubilalis, further confirmed field results with larval survival on kernels from the cross between non-Bt ears and Bt pollen reaching 60% compared with non-Bt crossed with non-Bt. These results suggest that non-Bt refuge plants, when planted in proximity to Bt plants, and cross-pollinated, can result in sublethal exposure of O. nubilalis and H. zea larvae to Bt and may undermine the high-dose/refuge resistance management strategy for corn hybrids expressing Cry1Ab.
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Claims 7
Claim · model-written summary
Crosses with maternal Bt plants led to low survival of O. nubilalis compared with the non-Bt cross.
- Taxon
- sweet corne0
- Treatment
- crosses with maternal Bt plantse1
- Interactor
- O. nubilalis
Ostrinia nubilalise1pest - Outcome
- survivale1
- Direction
- low levelse1
- Comparator
- non-Bt x non-Bt crosse1
- Setting
- Field studiese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The efficacy of nontransgenic sweet corn, Zea mays L., hybrids cross-pollinated by Bacillus thuringiensis (Bt) sweet corn hybrids expressing Cry1Ab toxin was evaluated in both field and laboratory studies in Minnesota in 2000”
e1“Field studies indicated that crosses with maternal Bt plants led to low levels of survival for both O. nubilalis and H. zea compared with the non-Bt x non-Bt cross”
Claim · model-written summary
Crosses with maternal Bt plants led to low survival of H. zea compared with the non-Bt cross.
- Taxon
- sweet corne0
- Treatment
- crosses with maternal Bt plantse1
- Interactor
- H. zea
.jpg?width=60)
Helicoverpa zeae1pest - Outcome
- survivale1
- Direction
- low levelse1
- Comparator
- non-Bt x non-Bt crosse1
- Setting
- Field studiese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“The efficacy of nontransgenic sweet corn, Zea mays L., hybrids cross-pollinated by Bacillus thuringiensis (Bt) sweet corn hybrids expressing Cry1Ab toxin was evaluated in both field and laboratory studies in Minnesota in 2000”
e1“Field studies indicated that crosses with maternal Bt plants led to low levels of survival for both O. nubilalis and H. zea compared with the non-Bt x non-Bt cross”
Claim · model-written summary
Non-Bt ears cross-pollinated with Bt pollen gave O. nubilalis larval survival of 43%.
- Taxon
- sweet corne0
- Treatment
- the cross between non-Bt ears and Bt pollene2
- Interactor
- O. nubilalisOstrinia nubilalise2pest
- Outcome
- survival ratese2
- Value
- 43e2
- Setting
- Minnesotae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The efficacy of nontransgenic sweet corn, Zea mays L., hybrids cross-pollinated by Bacillus thuringiensis (Bt) sweet corn hybrids expressing Cry1Ab toxin was evaluated in both field and laboratory studies in Minnesota in 2000”
e2“the cross between non-Bt ears and Bt pollen led to survival rates of 43 and 63% for O. nubilalis and H. zea larvae, respectively”
Claim · model-written summary
Non-Bt ears cross-pollinated with Bt pollen gave H. zea larval survival of 63%.
- Taxon
- sweet corne0
- Treatment
- the cross between non-Bt ears and Bt pollene2
- Interactor
- H. zeaHelicoverpa zeae2pest
- Outcome
- survival ratese2
- Value
- 63%e2
- Setting
- Minnesotae0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The efficacy of nontransgenic sweet corn, Zea mays L., hybrids cross-pollinated by Bacillus thuringiensis (Bt) sweet corn hybrids expressing Cry1Ab toxin was evaluated in both field and laboratory studies in Minnesota in 2000”
e2“the cross between non-Bt ears and Bt pollen led to survival rates of 43 and 63% for O. nubilalis and H. zea larvae, respectively”
Claim · model-written summary
The intermediate level of survival was reflected in the number of kernels damaged.
Verbatim
e0“The efficacy of nontransgenic sweet corn, Zea mays L., hybrids cross-pollinated by Bacillus thuringiensis (Bt) sweet corn hybrids expressing Cry1Ab toxin was evaluated in both field and laboratory studies in Minnesota in 2000”
e3“This intermediate level of survival also was reflected in the number of kernels damaged”
Claim · model-written summary
In laboratory bioassays, larval survival of O. nubilalis on kernels from the cross between non-Bt ears and Bt pollen was higher than on non-Bt crossed with non-Bt, reaching 60%.
- Taxon
- sweet corne0
- Treatment
- the cross between non-Bt ears and Bt pollene4
- Interactor
- O. nubilalisOstrinia nubilalise4pest
- Outcome
- larval survivale4
- Direction
- higherinferrede4
- Value
- 60%e4
- Comparator
- non-Bt crossed with non-Bte4
- Setting
- Laboratorye4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The efficacy of nontransgenic sweet corn, Zea mays L., hybrids cross-pollinated by Bacillus thuringiensis (Bt) sweet corn hybrids expressing Cry1Ab toxin was evaluated in both field and laboratory studies in Minnesota in 2000”
e4“Laboratory bioassays for O. nubilalis, further confirmed field results with larval survival on kernels from the cross between non-Bt ears and Bt pollen reaching 60% compared with non-Bt crossed with non-Bt”
Claim · model-written summary
Non-Bt refuge plants planted near Bt plants and cross-pollinated may undermine the high-dose/refuge resistance management strategy for Cry1Ab corn.
- Taxon
- sweet corne0
- Treatment
- non-Bt refuge plants, when planted in proximity to Bt plantse5
- Interactor
- O. nubilalisOstrinia nubilalise5pest
- Second interactor
- H. zeaHelicoverpa zeae5pest
- Outcome
- high-dose/refuge resistance management strategye5
- Direction
- may underminee5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The efficacy of nontransgenic sweet corn, Zea mays L., hybrids cross-pollinated by Bacillus thuringiensis (Bt) sweet corn hybrids expressing Cry1Ab toxin was evaluated in both field and laboratory studies in Minnesota in 2000”
e5“These results suggest that non-Bt refuge plants, when planted in proximity to Bt plants, and cross-pollinated, can result in sublethal exposure of O. nubilalis and H. zea larvae to Bt and may undermine the high-dose/refuge resistance management strategy for corn hybrids expressing Cry1Ab”
The same questions in other papers
transgenic · Ostrinia nubilalis · Zea mays (maize)Positive and negative results
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- no effect
- no effect
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See all 10 papers →transgenic · Helicoverpa zea · Zea mays (maize)Positive and negative results
17 papers in the same direction as this paper · 1 in the opposite direction · 3 reporting no difference from an alternative
- negative
- positive
- positive
18 papers more in this group
See all 22 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.