Publications by authors named "Geraldo U Berger"

Article Synopsis
  • - Rachiplusia nu (R. nu) has evolved from a secondary pest to a significant threat to soybean crops in Brazil and Argentina, particularly with those engineered to produce the Cry1Ac toxin, leading researchers to investigate resistance mechanisms.
  • - An experiment revealed that a resistant strain of R. nu can thrive on Cry1Ac soybean leaves, showing a resistance ratio greater than 736 times, while susceptible strains quickly died off; this resistance is autosomal recessive and monogenic with minimal fitness costs.
  • - The study found cross-resistance to another toxin (Cry1A.105) but not to Cry2Ab2, suggesting the combination of Cry1Ac, Cry1A.105, and Cry2Ab
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Rachiplusia nu Guenée is a polyphagous species able to develop on several cultivated and non-cultivated host plants. However, basic life history information about this pest on hosts is scarce. In this study, R.

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Background: Soybean is the third-greatest global commodity crop with respect to grain production, Brazil is the largest soybean producer in the world. We performed the first extensive survey including all the five main soybean cultivation regions in Brazil over three seasons (2018/2019, 2019/2020, and 2020/2021). A total of 2386 localities were sampled, corresponding to 145 municipalities in 11 states.

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Article Synopsis
  • The soybean bud borer in Brazil, initially identified as Crocidosema aporema, has seen recent outbreaks, but its identification and geographic history remain unclear.
  • A study involving molecular and morphological analysis revealed that 80 out of 90 collected samples were likely a different species in the Crocidosema genus, indicating that they may not be C. aporema.
  • The population growth of the soybean bud borer aligns with the expansion of soybean farming in Brazil, suggesting that increased agriculture may have contributed to the pest's rising numbers.
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Modern agricultural biotechnologies, such as those derived from genetic modification, are solutions that can enable an increase in food production, lead to more efficient use of natural resources, and promote environmental impact reduction. Crops with altered genetic materials have been extensively subjected to safety assessments to fulfill regulatory requirements prior to commercialization. The Brazilian National Technical Biosafety Commission (CTNBio) provides provisions for commercial release of transgenic crops in Brazil, including requiring information on pollen dispersion ability as part of environmental risk assessment, which includes pollen viability and morphology studies.

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Background: MON 87701 × MON 89788 × MON 87751 × MON 87708 soybean, that expresses Cry1A.105, Cry2Ab2, and Cry1Ac insecticidal proteins and confers tolerance to glyphosate and dicamba, is a potential tool for managing Spodoptera species in soybean fields in Brazil. In this study, we characterized the lethal and sub-lethal effects of Cry1A.

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Article Synopsis
  • Bacillus thuringiensis (Bt) crops, like Cry1Ac soybean, have been successfully adopted globally, offering strong protection against insect pests while benefiting farmers economically.
  • In Brazil, the cultivation of Cry1Ac soybean has led to a significant decrease (up to 50%) in insecticide use for managing lepidopteran pests over several years.
  • The data indicates a regional suppression of harmful moth species, demonstrating both environmental and economic advantages associated with Bt crop adoption in Brazilian agriculture.
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Background: The sugarcane borer (SCB), Diatraea saccharalis (Lepidoptera: Crambidae), is a key pest of maize in Argentina, and genetically modified maize, producing Bacillus thuringiensis (Bt) proteins, has revolutionized the management of this insect in South America. However, field-evolved resistance to some Bt technologies has been observed in SCB in Argentina. Here we assessed a new Bt technology, MON 95379, in the laboratory, greenhouse and field for efficacy against SCB.

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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.

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The soybean technology MON 87701 × MON 89788, expressing Cry1Ac and conferring tolerance to glyphosate, has been widely adopted in Brazil since 2013. However, pest shifts or resistance evolution could reduce the benefits of this technology. To assess Cry1Ac soybean performance and understand the composition of lepidopteran pest species attacking soybeans, we implemented large-scale sampling of larvae on commercial soybean fields during the 2019 and 2020 crop seasons to compare with data collected prior to the introduction of Cry1Ac soybeans.

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Genetically modified (GM) crops are one of the most valuable tools of modern biotechnology that secure yield potential needed to sustain the global agricultural demands for food, feed, fiber, and energy. Crossing single GM events through conventional breeding has proven to be an effective way to pyramid GM traits from individual events and increase yield protection in the resulting combined products. Even though years of research and commercialization of GM crops show that these organisms are safe and raise no additional biosafety concerns, some regulatory agencies still require risk assessments for these products.

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Background: Genetically modified MON 87701 × MON 89788 soybean (Glycine max) that expresses the Cry1Ac and EPSP-synthase proteins is a new Integrated Pest Management (IPM) tool for controlling Heliothis virescens in Brazil. To Support Insect Resistance Management (IRM) programs and understand the value of this event for IPM, we conducted laboratory and field studies to assess the biological activity of Cry1Ac protein expressed on Bt soybean against this insect pest.

Results: Heliothis virescens was highly susceptible to purified Cry1Ac protein [LC50 (FL 95%) = 0.

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Background: Genetically modified MON 87701 × MON 89788 soybean (Glycine max), which expresses the Cry1Ac and EPSP-synthase proteins, has been registered for commercial use in Brazil. To develop an Insect Resistance Management (IRM) program for this event, laboratory and field studies were conducted to assess the high-dose concept and level of control it provides against Anticarsia gemmatalis and Pseudoplusia includens.

Results: The purified Cry1Ac protein was more active against A.

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The soybean product MON 87701 × MON 89788 expresses both the cry1Ac gene derived from Bacillus thuringiensis and the cp4 epsps (5-enolpyruvylshikimate-3-phosphate synthase) gene derived from Agrobacterium sp. strain CP4. Each biotechnology-derived trait confers specific benefits of insect resistance and glyphosate tolerance, respectively.

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The compositions of a diverse range of commercially available conventional and genetically modified (GM; glyphosate-tolerant) soybean varieties from maturity groups 8 and 5, respectively, grown in the northern and southern soybean regions of Brazil during the 2007-2008 and 2008-2009 growing seasons were compared. Compositional analyses included measurement of essential macro- and micronutrients, antinutrients, and selected secondary metabolites in harvested seed as well as measurement of proximates in both forage and harvested seed. Statistical comparisons utilized a mixed analysis of variance model to evaluate the relative contributions of growing season, soybean growing region, production site, phenotype (GM or conventional), and variety.

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