What type of Bt corn is suitable for a region with diverse lepidopteran pests: A laboratory evaluation

Pest Management Science

et al. 2022

Self Cite

BACKGROUND: The invasive fall armyworm, Spodoptera frugiperda (J.E. Smith), has caused serious corn yield losses and increased the frequency of insecticide spraying on corn in Africa and Asia. Drawing lessons from the use of Bt corn to manage fall armyworm in the Americas, China released a certificate for the genetically modified corn event DBN3601T pyramidally expressing Cry1Ab and Vip3Aa19 for industrialization in 2021. Performance of the DBN3601T event against invasive fall armyworm in China was evaluated by plant tissue-based bioassays and field trials during 2019-2021.RESULTS: In the bioassays, tissues and organs of DBN3601T corn differed significantly in lethality to fall armyworm neonates in the order: leaf > husk > tassel and kernel > silk. In field trials, compared with non-Bt corn, DBN3601T corn greatly suppressed fall armyworm populations and damage; larval density, damage incidence, and leaf damage scores for DBN3601T corn were significantly lower than for non-Bt corn at different vegetative stages, and efficacy against larval populations during the 3 years ranged from 95.24% to 98.30%. CONCLUSION: A laboratory bioassay and 3-year field trials confirmed that DBN3601T corn greatly suppressed fall armyworm populations and has high potential as a control of this invasive pest, making it a key tactic for integrated management of fall armyworm in China.

Section: Discussionmentioning

confidence: 99%

Performance of the domestic Bt corn event expressing pyramided Cry1Ab and Vip3Aa19 against the invasive Spodoptera frugiperda (J. E. Smith) in China

Zhao

Yang

Pest Management Science

et al. 2022

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“…The oriental armyworm Mythimna separata (Walker), the bollworm Helicoverpa armigera (Hübner), and the fall armyworm Spodoptera frugiperda (J. E. Smith) are three major species of Lepidoptera insects that seriously affect global maize production. As a polyphagous, long-distance migratory, and sporadic corn pest, M. separata is notorious for its high feeding levels and can devour all available leaves when it abruptly outbreaks [ 2 , 3 , 4 ]. H. armigera is a widely distributed omnivorous pest that can migrate over long distances, and mainly feeds on leaves, silks, ears, and grains, thereby wreaking havoc on pollination, inducing ear rot, and reducing grain quality [ 2 , 5 , 6 ].…”

Section: Introductionmentioning

confidence: 99%

Molecular Characterization and Efficacy Evaluation of Transgenic Maize Harboring cry2Ab-vip3A-cp4epsps for Insect Resistance and Herbicide Tolerance

Zou

et al. 2023

Plants

Insect infestation and weed interference have a seriously negative impact on the growth, yield, and grain quality of maize. In this study, transgenic maize plants harboring three exogenous genes, cry2Ab, vip3A, and cp4epsps, that were constructed into a single T-DNA were developed for protection against insects and weeds. The transgene integration sites on the chromosomes in two transgenic maize events, CVC-1 and CVC-2, were determined using whole genome sequencing and specific PCR detection. As revealed by laboratory insect bioassays, these two transgenic events exhibited strong insecticidal toxicity against three major species of Lepidoptera insects, including Mythimna separata, Helicoverpa armigera, and Spodoptera frugiperda, with mortality rates exceeding 96%, 100%, and 100%, respectively, after six days of infestation. In addition, CVC-1 exhibited a high tolerance to glyphosate under field conditions. The successful expressions of cry2Ab, vip3A, and cp4epsps in various tissues at different developmental stages of CVC-1 were validated at the transcriptional and translational levels using quantitative real-time reverse transcription PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. These findings demonstrated that the transgenic maize CVC-1 developed using this triple gene construct has excellent insect resistance and herbicide tolerance, which may provide a valuable germplasm resource and data support for future maize breeding of insect and weed control.

“…DBN9936 and Ruifeng 125. Considering how maize‐feeding lepidopterans such as S. frugiperda are susceptible to Bt toxins (Li et al ., 2021 ), these maize varieties can lower pesticide usage intensity but concurrently trigger Bt resistance evolution. Non‐Bt maize refugia can delay resistance evolution (Hutchison et al ., 2010 ; Tellez‐Rodriguez et al ., 2014 ) and are implemented through seed mixtures of Bt and non‐Bt cultivars at the appropriate ratio also termed ‘refuge‐in‐the‐bag’ or structured refuges, i.e.…”

Section: Introductionmentioning

confidence: 99%

Bt maize can provide non‐chemical pest control and enhance food safety in China

Yang

Zhao

Plant Biotechnology Journal

et al. 2022

Self Cite

Summary China is the world's second‐largest maize producer and consumer. In recent years, the invasive fall armyworm Spodoptera frugiperda (J.E. Smith) has adversely affected maize productivity and compromised food security. To mitigate pest‐inflicted food shortages, China's Government issued biosafety certificates for two genetically modified (GM) Bt maize hybrids, Bt‐Cry1Ab DBN9936 and Bt‐Cry1Ab/Cry2Aj Ruifeng 125, in 2019. Here, we quantitatively assess the impact of both Bt maize hybrids on pest feeding damage, crop yield and food safety throughout China's maize belt. Without a need to resort to synthetic insecticides, Bt maize could mitigate lepidopteran pest pressure by 61.9–97.3%, avoid yield loss by 16.4–21.3% (range −11.9–99.2%) and lower mycotoxin contamination by 85.5–95.5% as compared to the prevailing non‐Bt hybrids. Yield loss avoidance varied considerably between experimental sites and years, as mediated by on‐site infestation pressure and pest identity. For either seed mixtures or block refuge arrangements, pest pressure was kept below established thresholds at 90% Bt maize coverage in Yunnan (where S. frugiperda was the dominant species) and 70% Bt maize coverage in other sites dominated by Helicoverpa armigera (Hübner) and Ostrinia furnacalis (Guenée). Drawing on experiences from other crop/pest systems, Bt maize in se can provide area‐wide pest management and thus, contribute to a progressive phase‐down of chemical pesticide use. Hence, when consciously paired with agroecological and biodiversity‐based measures, GM insecticidal crops can ensure food and nutrition security, contribute to the sustainable intensification of China's agriculture and reduce food systems' environmental footprint.