Resistance status of lepidopteran soybean pests following large-scale use of MON\xa087701\u2009\xd7\u2009MON\xa089788 soybean in Brazil

Renato J Horikoshi,Graham Head,Gustavo O Corazza,Celso Omoto,Samuel Martinelli,Elderson Ruthes,Patrick M Dourado,Daniela N Godoy,Oderlei Bernardi,Davi De S Fernandes,Altair A Semeão,Alberto S Corrêa,Alan Willse,Geraldo U Berger,Daniel R Sosa-Gómez,Adeney De F Bueno

doi:10.1038/s41598-021-00770-0

Abstract

Widespread adoption of MON 87701 × MON 89788 soybean, expressing Cry1Ac Bt protein and glyphosate tolerance, has been observed in Brazil. A proactive program was implemented to phenotypically and genotypically monitor Cry1Ac resistance in Chrysodeixis includens (Walker). Recent cases of unexpected injury in MON 87701 × MON 89788 soybean were investigated and a large-scale sampling of larvae on commercial soybean fields was performed to assess the efficacy of this technology and the distribution of lepidopteran pests in Brazil. No significant shift in C. includens susceptibility to Cry1Ac was observed eight years after commercial introduction of this technology in Brazil. F2 screen results confirmed that the frequency of Cry1Ac resistance alleles remains low and stable in C. includens. Unexpected injury caused by Rachiplusia nu (Guenée) and Crocidosema aporema (Walsingham) in MON 87701 × MON 89788 soybean was detected during the 2020/21 season, and studies confirmed a genetically based alteration in their susceptibility to Cry1Ac. MON 87701 × MON 89788 soybean remains effective against Anticarsia gemmatalis (Hübner), C. includens, Chloridea virescents (Fabricius) and Helicoverpa armigera (Hübner) in Brazil. However, there is evidence of field-evolved resistance to MON 87701 × MON 89788 soybean by the secondary soybean pests R. nu and C. aporema.

Highlights

Widespread adoption of MON 87701 × MON 89788 soybean, expressing Cry1Ac Bt protein and glyphosate tolerance, has been observed in Brazil
The proactive phenotypic and genotypic monitoring of Cry1Ac resistance did not show shifts in the susceptibility of C. includens that would lead to unexpected injury on MON 87701 × MON 89788 soybean in the field
An initial shift was observed from the genotypic resistance baseline monitoring carried out in 2014/1510, our findings indicated that the resistance allele frequency did not increase significantly over the following years

Summary

Introduction

Widespread adoption of MON 87701 × MON 89788 soybean, expressing Cry1Ac Bt protein and glyphosate tolerance, has been observed in Brazil. Recent cases of unexpected injury in MON 87701 × MON 89788 soybean were investigated and a large-scale sampling of larvae on commercial soybean fields was performed to assess the efficacy of this technology and the distribution of lepidopteran pests in Brazil. No significant shift in C. includens susceptibility to Cry1Ac was observed eight years after commercial introduction of this technology in Brazil. Unexpected injury caused by Rachiplusia nu (Guenée) and Crocidosema aporema (Walsingham) in MON 87701 × MON 89788 soybean was detected during the. There is evidence of field-evolved resistance to MON 87701 × MON 89788 soybean by the secondary soybean pests R. nu and C. aporema. Pest management in commercial fields of soybean [Glycine max L. Pest management in commercial fields of soybean [Glycine max L. (Merr.)] in South America has been transformed by the introduction of MON 87701 × MON 89788 soybean biotechnology

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