scholarly journals Estimation of Cry3Bb1 resistance allele frequency in field populations of western corn rootworm using a genetic marker

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alan Willse ◽  
Lex Flagel ◽  
Graham Head
Keyword(s):  
Allele Frequency ◽  
Western Corn Rootworm ◽  
Allele Frequencies ◽  
Chromosome 8 ◽  
Corn Belt ◽  
Corn Rootworm ◽  
Resistance Allele ◽  
Response To Selection ◽  
The Us ◽  
Causal Allele

Abstract Following the discovery of western corn rootworm (WCR; Diabrotica virgifera virgifera) populations resistant to the Bacillus thuringiensis (Bt) protein Cry3Bb1, resistance was genetically mapped to a single locus on WCR chromosome 8 and linked SNP markers were shown to correlate with the frequency of resistance among field-collected populations from the US Corn Belt. The purpose of this paper is to further investigate the relationship between one of these resistance-linked markers and the causal resistance locus. Using data from laboratory bioassays and field experiments, we show that one allele of the resistance-linked marker increased in frequency in response to selection, but was not perfectly linked to the causal resistance allele. By coupling the response to selection data with a genetic model of the linkage between the marker and the causal allele, we developed a model that allowed marker allele frequencies to be mapped to causal allele frequencies. We then used this model to estimate the resistance allele frequency distribution in the US Corn Belt based on collections from 40 populations. These estimates suggest that chromosome 8 Cry3Bb1 resistance allele frequency was generally low (<10%) for 65% of the landscape, though an estimated 13% of landscape has relatively high (>25%) resistance allele frequency.

scholarly journals Resistance to Bt Corn by Western Corn Rootworm (Coleoptera: Chrysomelidae) in the U.S. Corn Belt

2013 ◽  
Vol 4 (3) ◽  
pp. 1-6 ◽  
Author(s):  
Eileen M. Cullen ◽  
Michael E. Gray ◽  
Aaron J. Gassmann ◽  
Bruce E. Hibbard
Keyword(s):  
Western Corn Rootworm ◽  
Corn Belt ◽  
Bt Corn ◽  
Corn Rootworm ◽  
The U.S

scholarly journals A new Bacillus thuringiensis protein for Western corn rootworm control

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242791
Author(s):  
Yong Yin ◽  
Stanislaw Flasinski ◽  
William Moar ◽  
David Bowen ◽  
Cathy Chay ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Insect Pests ◽  
Diabrotica Virgifera Virgifera ◽  
Field Resistance ◽  
Western Corn Rootworm ◽  
Transgenic Maize ◽  
Corn Rootworm ◽  
The Us ◽  
Central Regions ◽  
Root Protection

The Western corn rootworm (WCR) Diabrotica virgifera virgifera LeConte is one of the most economically important insect pests in North America. Since 2003, transgenic maize expressing WCR-active proteins from Bacillus thuringiensis (Bt) have been widely adopted as the main approach to controlling WCR in the U.S. However, the emergence of field resistance to the Bt proteins in current commercial products has been documented in recent years, highlighting the need to develop additional tools for controlling this devasting pest. Here we report the discovery of Vpb4Da2 (initially assigned as Vip4Da2), a new insecticidal protein highly selective against WCR, through high-throughput genome sequencing of a Bt strain sourced from grain dust samples collected in the eastern and central regions of the US. Vpb4Da2 contains a sequence and domain signature distinct from families of other WCR-active proteins. Under field conditions, transgenic maize expressing Vpb4Da2 demonstrates commercial-level (at or below NIS 0.25) root protection against WCR, and reduces WCR beetle emergence by ≥ 97%. Our studies also conclude that Vpb4Da2 controls WCR populations that are resistant to WCR-active transgenic maize expressing Cry3Bb1, Cry34Ab1/Cry35Ab1 (reassigned as Gpp34Ab1/Tpp35Ab1), or DvSnf7 RNA. Based on these findings, Vpb4Da2 represents a valuable new tool for protecting maize against WCR.

scholarly journals LEVEL OF LARVAL ATACK ON MAIZE ROOTS AS A CONSEQUENCE OF ARTIFICIAL INFESTATION WITH WESTERN CORN ROOTWORM EGGS

AGROFOR ◽  
2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Snežana TANASKOVIĆ ◽  
Branka POPOVIĆ ◽  
Sonja GVOZDENAC ◽  
Zsolt KARPÁTI ◽  
Csengele BÓGNAR ◽  
...  
Keyword(s):  
Ostrinia Nubilalis ◽  
Control Plant ◽  
Western Corn Rootworm ◽  
Corn Belt ◽  
Corn Rootworm ◽  
Diabrotica Virgifera ◽  
Maize Field ◽  
Artificial Infestation ◽  
Maize Roots ◽  
Vojvodina Province

The Western corn rootworm (WCR), Diabrotica virgifera sp. virgifera(Col.,Chrysomelidae), is an oligophagous pest native in America. WCR is a maizepest present in all regions of the Corn Belt. It is an invasive species which was, inEurope, first identified in Serbia, in 1992, near the Belgrade airport. The presenceof this pest in maize field can cause losses and plant damages up to 100%. A fieldexperiment was carried out in Bečej, Vojvodina province (Serbia), during 2014 and2015. In the field, 96 plants (maize cultivar NS 640), arranged in 48 pairs wereselected. Each pair consisted of one plant artificially infested with WCR eggs (Dplant) and the control plant (C plant). In both years, the experiment in the field wasregularly inspected, once a week. During each observation, the presence of "gooseneck" symptoms was recorded, and the number of plants damaged by the mostimportant stem boring and leaf feeding insects (Ostrinia nubilalis, Helicoverpaarmigera, H. zeae, aphids, mites, cicadas, etc. ) was counted. Root damages wereassessed at the end of the experiment (September), according to Ostlie and Notzel(1987), on scale 1-6. Comparing the root damages on C and D plants, less rootdamages were established on C plants. Only six i. e. four D plants had healthy roots(rate 1) during 2014 and 2015, respectively. Between D plants in 2014, the mostdamaged were14 plants, with the rate 3 (least one root chewed to within 1½ inches(3. 8 cm) of the plant). In 2015, severe damages were registered on 18 plants,which were ranked as level 6 (with three or more nodes destroyed). Only two Cplants during vegetation 2014-2015were registered with damages with rate 5 (twonodes destroyed) and rate 6 (three or more nodes destroyed), respectively.

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