scholarly journals Genetically modified soybean expressing insecticidal protein (Cry1Ac): Management risk and perspectives

FACETS ◽  
2017 ◽  
Vol 2 (1) ◽  
pp. 496-512 ◽  
Author(s):  
Silvia Martins-Salles ◽  
Vilmar Machado ◽  
Laura Massochin-Pinto ◽  
Lidia M. Fiuza

A Bt soybean has been recently developed, thus, efficiently regulating the populations of major lepidopteran pests. However, in other cases, these benefits have been reduced or lost because of the rapid evolution of pest resistance to the Bt toxins in transgenic crops. When pest populations are exposed to Bt crops and to refuges (non- Bt plants), the evolution of resistance is governed by the fitness of resistant individuals relative to susceptible individuals for both the presence and absence of Bt toxins. One major ecological concern regarding the biosafety of Bt crops on the environment is their potential effects on non-target organisms, especially predators and parasitoids that play an important role in pest control. This information is important for supporting insect resistance management (IRM) programs and for improving agricultural practices in a crop production system with Bt plants. Before the use of Bt plants for insect pest control in Brazil is adopted, IRM programs should be established to ensure the sustainability of this technology for integrated pest management (IPM). This review presents data on Bt soybean and lepidopteran pests as well as on the importance of natural enemies as a form of biological control, and applications for IPM and IRM.

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Zhaojiang Guo ◽  
Shi Kang ◽  
Xun Zhu ◽  
Jixing Xia ◽  
Qingjun Wu ◽  
...  

Author(s):  
G P Dively ◽  
T P Kuhar ◽  
S Taylor ◽  
H B Doughty ◽  
K Holmstrom ◽  
...  

Abstract As part of an insect resistance management plan to preserve Bt transgenic technology, annual monitoring of target pests is mandated to detect susceptibility changes to Bt toxins. Currently Helicoverpa zea (Boddie) monitoring involves investigating unexpected injury in Bt crop fields and collecting larvae from non-Bt host plants for laboratory diet bioassays to determine mortality responses to diagnostic concentrations of Bt toxins. To date, this monitoring approach has not detected any significant change from the known range of baseline susceptibility to Bt toxins, yet practical field-evolved resistance in H. zea populations and numerous occurrences of unexpected injury occur in Bt crops. In this study, we implemented a network of 73 sentinel sweet corn trials, spanning 16 U.S. states and 4 Canadian provinces, for monitoring changes in H. zea susceptibility to Cry and Vip3A toxins by measuring differences in ear damage and larval infestations between isogenic pairs of non-Bt and Bt hybrids over three years. This approach can monitor susceptibility changes and regional differences in other ear-feeding lepidopteran pests. Temporal changes in the field efficacy of each toxin were evidenced by comparing our current results with earlier published studies, including baseline data for each Bt trait when first commercialized. Changes in amount of ear damage showed significant increases in H. zea resistance to Cry toxins and possibly lower susceptibility to Vip3a. Our findings demonstrate that the sentinel plot approach as an in-field screen can effectively monitor phenotypic resistance and document field-evolved resistance in target pest populations, improving resistance monitoring for Bt crops.


2016 ◽  
Vol 1 (2) ◽  
pp. 55
Author(s):  
. Nurindah ◽  
Dwi Adi Sunarto ◽  
. Sujak

<p>Pengelolaan serangga hama dalam good agricultural practices (GAP) menerapkan cara-cara memproduksi tanaman yang berkualitas dengan menggunakan metode-metode pengelolaan serangga hama yang dapat meningkatkan keragaman genetik, keanekaragaman hayati dan habitatnya, serta terhadap struktur sosial dan komunitas pedesaan. Strategi ‘tolak-tarik’ (‘push-pull’ strategy) merupakan salah satu teknik pengenda-lian hama yang berprinsip pada komponen pengendalian non-toksik, sehingga dapat diintegrasikan dengan metode-metode lain yang dapat menekan perkembangan populasi hama dengan meningkatkan peran mu-suh alami pada pertanaman. Penelitian tanaman perangkap untuk pengendalian serangga tanaman temba-kau cerutu besuki dilaksanakan di Desa Antirogo, Kecamatan Sumbersari, Jember pada bulan Agustus–De-sember 2008. Pada penelitian ini digunakan tanaman jarak kepyar, sorgum, dan kacang hijau sebagai ta-naman penarik yang ditanam secara berlajur sebanyak satu atau dua baris di antara delapan baris tanaman tembakau. Sebagai pembanding adalah tanaman tembakau monokultur dengan penyemprotan insektisida secara berjadwal setiap empat hari sejak 10–50 HST dan petak kontrol, yaitu tanaman monokultur tanpa pe-ngendalian hama sama sekali. Penelitian disusun dalam rancangan acak kelompok dengan lima perlakuan yang diulang lima kali. Penelitian ini bertujuan untuk memilih tanaman perangkap yang dapat digunakan da-lam program pengendalian hama cerutu besuki secara terpadu. Hasil penelitian menunjukkan bahwa tanam-an jarak kepyar, sorgum, dan kacang hijau dapat digunakan sebagai tanaman perangkap, sehingga populasi hama pada tembakau dapat ditekan hingga 50% dan diperoleh produksi daun basah (8,62–9,17 ton/ha vs 8,42 ton/ha) dan kerosok (1,01–1,07 ton/ha vs 0,96 ton/ha) dengan mutu yang lebih baik dibandingkan kontrol (indeks mutu: 62,5–64,4 vs 62,1). Penggunaan kacang hijau memberikan produksi kerosok dengan mutu baik tertinggi, sehingga memberikan penerimaan yang lebih tinggi dibandingkan perlakuan lain. Pe-nyemprotan insektisida secara berjadwal untuk mengendalikan serangga hama tembakau cerutu besuki na-oogst merupakan tindakan pengendalian yang tidak efektif dan juga tidak efisien, karena sasaran serangga hama tidak tepat, sehingga terjadi pemborosan biaya input.</p><p> </p><p>Pest management in good agricultural practices concept use methods of qualified crop production processes with considering increasing genetic diversity, biodiversity and its habitat as well as social structure and village community. Push-and-pull strategy is a pest control method with a non-toxic method principal so that it can be integrated with other methods to suppress pest population and increase natural enemies’ populationin the ecosystems. Research on trap crops used for controlling insect pests on besuki-cigar tobaccowas conducted on besuki-cigar tobacco fields planted after rice (na-oogst) in Jember on August–December2008. In this research activity we used castor, sorghum, and mungbean as trap crops, each was intercroppedin one or two rows between eight rows of tobacco plants. We used monoculture tobacco plants withscheduled sprays of chemical insecticide, i.e. 4 days-spray interval on 10–50 days after planting and controlplots without any insect pest control for comparison with the use of trap crops. The research was arrangedin randomized block design with five treatments and five replicates. The aim of the research is to choose asuitable trap crop used in pest management of besuki cigar tobacco. The results showed that castor, sorghum,and mungbean could be use as trap crops to suppress insect pests population up to 25% on tobaccoplants and would give leaf production (1.01–1.07 ton/ha vs 0,96 ton cured leaves/ha) with a better quality(quality index: 62.5–64.4 vs 62.1) than those of control. Mungbean is the best trap crop as it gives a highestleaf production with a better quality, so that gives a better income than those of other treatments. Scheduledchemical insecticide sprays to control insect pest on na-oogst-besuki cigar tobacco was not either effectiveor efficient, because the target pest was not right, so that causing a wasteful input cost.</p>


Toxins ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 454 ◽  
Author(s):  
Jing Yang ◽  
Yudong Quan ◽  
Prabu Sivaprasath ◽  
Muhammad Shabbir ◽  
Zhenying Wang ◽  
...  

The oriental armyworm (OAW), Mythimna separata (Walker), is a destructive pest of agricultural crops in Asia and Australia. Commercialized Bt crops have performed very well against their target pests; however, very few studies have been done on the susceptibility of OAW to Bt toxins in either sprays or expressed in Bt crops. In this work, we evaluated the toxicities of Cry1Ab, Cry1Ac, Cry1Ah, Cry1Fa, Cry2Aa, Cry2Ab, Cry1Ie, Vip3Aa19, Vip3Aa16, and Vip3Ca against OAW neonate larvae, as well as the interaction between Cry and Vip toxins. The results from bioassays revealed that LC50 (lethal concentration for 50% mortality) values ranged from 1.6 to 78.6 μg/g (toxin/diet) for those toxins. Among them, Vip3 proteins, along with Cry1A proteins and Cry2Aa, were the ones with the highest potency, with LC50 values ranging from 1.6 to 7.4 μg/g. Synergism between Cry and Vip toxins was observed, being high in the combination of Vip3Aa16 with Cry1 toxins, with synergetic factors ranging from 2.2 to 9.2. The Vip3Ca toxin did not show any synergistic effect with any of the toxins tested. These results can help in designing new combinations of pyramiding genes in Bt crops, as well as in recombinant bacteria, for the control of OAW as well as for resistance management programs.


2009 ◽  
Vol 102 (2) ◽  
pp. 717-732 ◽  
Author(s):  
Nina Alphey ◽  
Michael B. Bonsall ◽  
Luke Alphey

Author(s):  
Hasrat Arjjumend ◽  
Konstantia Koutouki ◽  
Olga Donets

The use of unsustainable levels of chemical fertilizers and plant protection chemicals has resulted in a steady decline in soil and crop productivity the world over. Soil biology has undergone irreversible damage, coupled with a high concentration of toxic chemical residues in plant tissues and human bodies. Agricultural practices must evolve to sustainably meet the growing global demand for food without irreversibly damaging soil. Microbial biocontrol agents have tremendous potential to bring sustainability to agriculture in a way that is safe for the environment. Biopesticides do not kill non-target insects, and biosafety is ensured because biopesticides act as antidotes and do not lead to chemical contamination in the soil. This article is part of a larger study conducted in Ukraine by researchers at the Université de Montréal with the support of Mitacs and Earth Alive Clean Technologies. The responses of farmers who use biofertilizers (“user farmers”) and those who do not (“non-user farmers”), along with the responses of manufacturers or suppliers of biofertilizers, and research and development (R&D) scientists are captured to demonstrate the advantages of applying microbial biopesticides to field crops. Participants reported a 15-30% increase in yields and crop production after the application of biopesticides. With the use of biopesticides, farmers cultivated better quality fruits, grains, and tubers with a longer shelf life. Moreover, while the risk of crop loss remains high (60-70%) with chemically grown crops, this risk is reduced to 33% on average if crops are grown using biopesticides. The findings indicate that a large proportion of farmers would prefer to use biopesticides if they are effective and high quality products. In this context, the quality and effectiveness of products is therefore very important. Despite their benefits to soil, human health, and ecosystems, biopesticides face significant challenges and competition vis-à-vis synthetic pesticides for a variety of reasons. Therefore, the development of biopesticides must overcome the problems of poor quality products, short shelf life, delayed action, high market costs, and legal/registration issues.


2014 ◽  
Vol 20 ◽  
pp. 25-32
Author(s):  
N Sapna Bai ◽  
OK Remadevi ◽  
TO Sasidharan ◽  
M Balachander ◽  
Priyadarsanan Dharmarajan

Context: Entomopathogenic fungi have been recognized as viable alternate options to chemicals in insect pest control. Unlike other potential biocontrol agents, fungi do not have to be ingested to infect their hosts but invade directly through the cuticle. Entry into the host involves both enzymic degradation of the cuticle barrier and mechanical pressure. Production of a range of cuticle degrading enzymes is an important event in the interaction of entomopathogenic fungi and host. Enzyme secretion is believed to be a key contributor for the virulence of a fungal isolate. Objectives: The potentiality of nine isolates of M. anisopliae were tested to produce to produce three important cuticle degrading enzymes, viz., chitinase, protease and lipase. Materials and Methods: Nine isolates of M. anisopliae were evaluated for chitinase, protease and lipase enzyme production by determining the enzyme index and activities. Results: Chitinase index of these isolates were ranged from 1.5 to 2.2 and chitinolytic activity from 0.525 to 1.560 U/ml. The isolates showed protease index in the range of 1.2 to 3.3 and the activity ranged from 0.020 to 0.114 U/ml. Lipase index ranged from 1.15 to 7.0 and the enzyme activity ranged from 0.153 to 0.500 U/ml. A strong relationship was observed between virulence of the isolates and cuticle degrading enzyme production as increased enzyme production was observed for virulent isolates. Conclusion: In the present study three isolates as (MIS2, MIS7 and MIS13) demonstrated cuticle degrading enzyme (CDE) that indicate higher virulence based on the bioassay conducted earlier by the authors as strongly substantiating the role of CDEs is considered the virulence of Metarhizium isolates. So, these isolates may be as ecofriendly insect-pest control agent in future. DOI: http://dx.doi.org/10.3329/jbs.v20i0.17648 J. bio-sci. 20: 25-32, 2012


Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 60
Author(s):  
Vincenzo Michele Sellitto ◽  
Severino Zara ◽  
Fabio Fracchetti ◽  
Vittorio Capozzi ◽  
Tiziana Nardi

From a ‘farm to fork’ perspective, there are several phases in the production chain of fruits and vegetables in which undesired microbial contaminations can attack foodstuff. In managing these diseases, harvest is a crucial point for shifting the intervention criteria. While in preharvest, pest management consists of tailored agricultural practices, in postharvest, the contaminations are treated using specific (bio)technological approaches (physical, chemical, biological). Some issues connect the ‘pre’ and ‘post’, aligning some problems and possible solution. The colonisation of undesired microorganisms in preharvest can affect the postharvest quality, influencing crop production, yield and storage. Postharvest practices can ‘amplify’ the contamination, favouring microbial spread and provoking injures of the product, which can sustain microbial growth. In this context, microbial biocontrol is a biological strategy receiving increasing interest as sustainable innovation. Microbial-based biotools can find application both to control plant diseases and to reduce contaminations on the product, and therefore, can be considered biocontrol solutions in preharvest or in postharvest. Numerous microbial antagonists (fungi, yeasts and bacteria) can be used in the field and during storage, as reported by laboratory and industrial-scale studies. This review aims to examine the main microbial-based tools potentially representing sustainable bioprotective biotechnologies, focusing on the biotools that overtake the boundaries between pre- and postharvest applications protecting quality against microbial decay.


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