Frequency of Cry1F resistance alleles in <i>Spodoptera frugiperda</i>
 (Lepidoptera: Noctuidae) in Brazil

Farias, Juliano Ricardo; Andow, David A.; Horikoshi, Renato J.; Bernardi, Daniel; Ribeiro, Rebeca da Silva; Nascimento, Antônio Rogério Bezerra do; Santos, Antonio Carlos; Omoto, Celso

doi:10.1002/ps.4274

Cited by 38 publications

(26 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…At this time localized field control failures were already being identified in areas with higher allele frequencies. 31 The allele frequency of 0.0033 found in this study is 3.67 times higher than that reported by Bernardi et al for S. frugiperda on Vip3Aa20 between 2013 and 2014 using the same methodology 6 -an expressive increase given the short lapse of time between the studies. In regard to each state, when we compared both monitoring studies, we saw a reduction in estimated allele frequency for MT from 0.0047 to 0.0021 and MS from 0.0043 to 0.0031, and an allele frequency increase for PR from 0.0020 to 0.0071, BA from 0.0017 to 0.0027 and GO from 0.0021 to 0.0052. wileyonlinelibrary.com/journal/ps Regional differences can be in part attributed to the environmental conditions of different collection years or sample size, but an allelic frequency difference of more than ten times for some states cannot be only attributed to random biological differences.…”

Section: Discussioncontrasting

confidence: 62%

“…A higher allele frequency was reported for Cry1F in Brazil with a mean frequency of 0.143. At this time localized field control failures were already being identified in areas with higher allele frequencies …”

Section: Discussionmentioning

confidence: 97%

“…For other insecticidal proteins and pests using the F 1 screen method, allelic frequencies ranged from 0.0015 to 0.037, for all cases, no control failure occurred. A higher value (0.25) was found for Cry1F in 2012 for the resistance allele frequency of S. frugiperda in Brazil, where localized control failures were already being detected in the field in areas with hybrids expressing this protein. Thus, using the F 1 screen method the resistance allele frequency found is low.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Geographical distribution of Vip3Aa20 resistance allele frequencies in Spodoptera frugiperda (Lepidoptera: Noctuidae) populations in Brazil

Amaral

Guidolin

Salmeron

et al. 2019

Pest Management Science

Self Cite

View full text Add to dashboard Cite

BACKGROUND The use of Bt plants has been the main strategy for controlling the fall armyworm Spodoptera frugiperda (J. E. Smith) in Brazil. However, many resistance cases were already registered. The resistance of S. frugiperda to the Vip3Aa20 protein was recently characterized under laboratory conditions but it is still efficient under field conditions. Here, resistance monitoring studies were conducted using phenotypic (purified protein and Bt maize leaves) and genotypic (F1 and F2 screen) methods to support insect resistance management (IRM) programs and preserve Vip3Aa20 technology on maize. RESULTS Phenotypic monitoring with purified protein showed two populations significantly different from the susceptible strain on the second crop season in 2016. This number increased for the first and second crop seasons in 2017 in several regions. The genotypic monitoring estimated a mean frequency of the resistance allele of 0.0027 for the F1 screen and 0.0033 for the F2 screen. Three new resistant strains to Vip3Aa20 were selected from F2 screen assays. Complementation tests on these new resistant strains were positive with the previous resistant strain. CONCLUSION Here we showed that the resistance allele of S. frugiperda to Vip3Aa20 protein is widely distributed in maize‐producing regions in Brazil and its frequency increases throughout crop seasons. © 2019 Society of Chemical Industry

show abstract

Section: Discussioncontrasting

confidence: 62%

Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Geographical distribution of Vip3Aa20 resistance allele frequencies in Spodoptera frugiperda (Lepidoptera: Noctuidae) populations in Brazil

Amaral

Guidolin

Salmeron

et al. 2019

Pest Management Science

Self Cite

View full text Add to dashboard Cite

show abstract

“…Smith, 1797) (Lepidoptera: Noctuidae), popularly known as the fall armyworm. Due to the high control rate provided by the Bt technology, farmers grow Bt maize throughout the year, without adopting adequate refuge areas (Storer et al, 2010;Farias et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Survival and nutritional indexes of Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) maintained in Bt maize for five generations

Silva

Maggioni

Ferreira

et al. 2019

Agraria

View full text Add to dashboard Cite

The selection pressure generated by the incorrect use of Bt maize might result in Spodoptera frugiperda individuals resistant to the toxins synthesized by the plant. In this study was evaluated the nutritional parameters of Spodoptera frugiperda submitted to the maize that synthesize the toxins Cry1F, Cry1A105-Cry2Ab2 and Vip3Aa20, during five subsequent generations of selection pressure. The caterpillars were submitted to the treatments: Non-Bt maize (CONV), Cry1F (Bt1), Cry1A105/Cry2Ab (Bt2) and Vip3Aa20 (VIP1, VIP2 and VIP3) and exposed for a period of four days in each cycle, for five successive generations. The larval survival of S. frugiperda was evaluated in five generations. The consumed leaf area was quantified in the second generation and the nutritional indexes in the latter ones. The results indicate that caterpillars of S. frugiperda from VIPs lineage presented the lowest percentage of survival, with a high Metabolic Cost and a considerable efficiency reduction in the conversion of the digested and ingested food. The lineage maintained in VIP2 showed the lowest leaf consumption (83.13%). However, the action of Vip3Aa20 toxin on S. frugiperda resulted in a higher Metabolic Cost in reduction of leaf area consumption. However, from the third generation on there is a survival of insects exposed to Bt toxins, suggesting the surviving potential of this species in Bt maize subjected to continuous exposure to this technology. Sobrevivência e índices nutricionais de Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) mantida em milho Bt por cinco gerações RESUMO: A pressão de seleção gerada pelo uso incorreto do milho Bt pode resultar em indivíduos de Spodoptera frugiperda resistentes às toxinas expressadas pela planta. Neste trabalho foi determinado os parâmetros nutricionais de Spodoptera frugiperda submetida aos milhos que sintetizam as toxinas Cry1F, Cry1A105-Cry2Ab2 e Vip3Aa20, durante cinco gerações. As lagartas foram submetidas aos tratamentos: Milho não-Bt (CONV), Cry1F (Bt1), Cry1A105/Cry2Ab (Bt2) e Vip3Aa20 (VIP1, VIP2 e VIP3) e expostas por um período de quatro dias em cada ciclo, por cinco gerações sucessivas. Foi avaliada a sobrevivência larval de S. frugiperda em cinco gerações. A área foliar consumida foi quantificada na segunda geração e nas posteriores foram determinados os índices nutricionais. As lagartas de S. frugiperda, da geração mantida no milho VIPs, apresentaram menor porcentagem de sobrevivência, com um alto Custo Metabólico e considerável redução na Eficiência na conversão do alimento digerido e Eficiência na conversão do alimento ingerido. A geração mantida no Hibrido VIP2 apresentou o menor consumo foliar (83,13%). Contudo a ação da toxina Vip3Aa20 sobre S. frugiperda resultou no maior Custo Metabólico em redução no consumo de área foliar. Contudo a partir da terceira geração observa-se uma sobrevivência de insetos expostos as toxinas Bt, sugerindo o potencial desta espécie em sobreviver aos milhos Bt quando submetidas a exposição contínua a esta tecnologia. Palavra...

show abstract

“…A large number of commercial Bt maize and cotton varieties expressing Bt proteins from the Cry1 family, such as Cry1F, Cry1A.105, Cry1Ac, and Cry1Ab, have been developed. Cases of fall armyworm resistance have already been reported for Cry1F (Farias et al 2016), Cry1Ab ) and Cry1A105 and Cry2Ab2 (Bernardi et al 2015). In addition, results for mortality have demonstrated cross-resistance between these proteins expressed in different Bt crops ).…”

Section: Introductionmentioning

confidence: 95%

Exploiting next generation sequencing techniques (NGS) to identify molecular markers for monitoring the resistance of <i>Spodoptera frugiperda</i> (J.E. Smith) (Lepidoptera: Noctuidae) to insecticides and Bt proteins

Nascimento¹,

Omoto²

View full text Add to dashboard Cite

Exploiting next generation sequencing techniques (NGS) to identify molecular markersfor monitoring the resistance of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) to insecticides and Bt proteinsIn this study we used Next-generation sequencing "NGS" for DNA and RNA sequencing to search for molecular markers associated with resistance of Spodoptera frugiperda (J.E. Smith) to insecticides and Bacillus thuringiensis Berliner (Bt) proteins. For this purpose, we selected S. frugiperda resistant strains to insecticides (chlorpyrifos, lambdacyhalothrin, lufenuron, teflubenzuron and spinosad) belonging to different chemical groups and to the YieldGard VT-PRO ® maize expressing Cry1A.105 and Cry2Ab2 proteins. The results of gene expression between resistant and susceptible strains of the neurotoxic insecticides chlorpyrifos and lambda-cyhalothrin demonstrated 935 differentially expressed genes associated with chlorpyrifos resistance and 241 differentially expressed genes associated with lambda-cyhalothrin. Most of these genes was related to high levels of expression in detoxification enzymes, especially the CYP3 and CPY6 families. Regarding to the insecticide teflubenzuron, the inheritance of resistance was characterized as autosomal, incompletely recessive and polygenic. The results of gene expression between resistant and susceptible strains of teflubenzuron indicated 3,519 differentially expressed transcripts, mainly detoxification enzymes from the GSTs, UGTs, P450s, CEs, as well as transport and regulation genes. This gene expression profile was also identified to YieldGard VT-PRO ® resistant strain, which also demonstrated changes in the expression levels of other gene groups such as cadherin, aminopeptidases and alkaline phosphatase. Finally, to identify SNP markers associated with resistance of S. frugiperda to insecticides and Bt proteins, we used a genotyping by sequencing (GBS) protocol to all resistant strains and the susceptible strain. A total of 4,276 SNPs was recovered after filtering processes, where 53 polymorphic loci under selection were statistically significant (FDR≤0.047) and none of them was associated with coding regions. However, several of these SNPs were associated with regulatory regions of the genome. Analyses using DAPC resulted in the formation of seven clusters, with the susceptible line being separated from all resistant strains. The resistant strain to chlorpyrifos presented an exclusive cluster separated from the other resistant strains, which were grouped together. The association analyses between susceptible and resistant strains indicated 17 loci associated with all resistant strains, 114 loci associated with resistance to chlorpyrifos, 105 to lambda-cyhalothrin, 84 to lufenuron, 87 to teflubenzuron, 108 to spinosad and 62 to YieldGard VT-PRO ® maize. Therefore, we can conclude that the resistance processes associated to insecticides and Bt toxins are due to a large number of molecular modifications at specific sites associated with detoxification and regulation processes...

show abstract

Frequency of Cry1F resistance alleles in Spodoptera frugiperda (Lepidoptera: Noctuidae) in Brazil

Cited by 38 publications

References 24 publications

Geographical distribution of Vip3Aa20 resistance allele frequencies in Spodoptera frugiperda (Lepidoptera: Noctuidae) populations in Brazil

Geographical distribution of Vip3Aa20 resistance allele frequencies in Spodoptera frugiperda (Lepidoptera: Noctuidae) populations in Brazil

Survival and nutritional indexes of Spodoptera frugiperda (J.E. Smith, 1797) (Lepidoptera: Noctuidae) maintained in Bt maize for five generations

Exploiting next generation sequencing techniques (NGS) to identify molecular markers for monitoring the resistance of <i>Spodoptera frugiperda</i> (J.E. Smith) (Lepidoptera: Noctuidae) to insecticides and Bt proteins

Contact Info

Product

Resources

About