GMO Research
Abstract: Western corn rootworm, Diabrotica virgifera virgifera LeConte, is a serious pest of corn and is managed with corn that produces insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt). Beginning in 2009, resistance to Cry3Bb1 corn, and severe injury to Cry3Bb1 corn in the field, was observed in Iowa. However, few data exist on …
Abstract: Many researchers have hailed transgenic insecticidal crops—plants modified to produce insecticidal proteins derived from genes of the bacterium Bacillus thuringiensis (Bt)—as the most important technological advancement in insect pest management since the development of synthetic insecticides (Vaeck et al. 1987, Koziel et al. 1993, Perlak et al. 1990, 1993). At least 18 transgenic insecticidal …
Abstract: The widespread planting of corn genetically modified to produce Bacillus thuringiensisendotoxin has led to speculation that pollen from these fields might adversely affect nearby nontarget lepidopterans. A previous study of Bt corn engineered with Monsanto event 810 failed to detect an effect of pollen exposure on the black swallowtail, Papilio polyxenes, in either the …
Abstract: Bt-corn is genetically engineered to express proteins from the common soil bacterium Bacillus thuringiensis which presents specific toxicity to targeted insect pests. One type of Bt-corn expresses the Cry1Ab protein that provides protection against certain lepidopteran pests, mainly the European corn borer (Ostrinia nubilalis) and the Mediterranean stalk borer (Sesamia nonagroides). Vast areas of …
Abstract: Paired-choice assays in a tritrophic system have been carried out to study the influence of transgenic Bacillus thuringiensisvar. kurstaki (Berliner) corn plants on prey preference of the predator Chrysoperla carnea (Stephens). Plants used were a transgenic B. thuringiensis-expressing (Cry1Ab) corn hybrid and the corresponding isogenic untransformed B. thuringiensis-free hybrid. Two different prey species were …
Abstract: Transgenic crops producing Bacillus thuringiensis (Bt) toxins for insect control have been successful, but their efficacy is reduced when pests evolve resistance. To delay pest resistance to Bt crops, the U.S. Environmental Protection Agency (EPA) has required refuges of host plants that do not produce Bt toxins to promote survival of susceptible pests. Such …
Abstract: Laboratory feeding experiments using transgenic Bacillus thuringiensis variety kurstaki(Berliner) corn plants have been carried out to study the effects of B. thuringiensis -fed herbivores (i.e., prey), on the predator Chrysoperla carnea Stephens. Host plants were a transgenic B. thuringiensis -expressing (CrylAb) corn hybrid and the corresponding untransformed, B. thuringiensis -free corn hybrid. Two different …
Abstract: Transgenic crops that produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) are widely planted to manage pest insects. One of the primary pests targeted by Bt corn in the United States is western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae). Cry3Bb1 corn for management of western corn rootworm was commercialized in …
Abstract: The effect of genetically modified corn (event MON810, YieldGard Corn Borer) expressing the Bacillus thuringiensis sp. kurstaki (Berliner) (Bt) endotoxin, Cry1Ab, on the survival of western bean cutworm, Striacosta albicosta (Smith), larvae was examined during intraguild competition studies with either European corn borer, Ostrinia nubilalis (Hübner), or corn earworm, Helicoverpa zea (Boddie), larvae. Competition …
Abstract: To delay evolution of insect resistance to transgenic crops producing Bacillus thuringiensis (Bt) toxins, nearby “refuges” of host plants not producing Bt toxins are required in many regions. Such refuges are expected to be most effective in slowing resistance when the toxin concentration in Bt crops is high enough to kill all or nearly …
Abstract: When glyphosate is applied to glyphosate-resistant (GR) crops, drift to nonglyphosate-resistant (non-GR) crops may cause significant injury and reduce yields. Tools are needed to quantify injury and predict crop losses. In this study, glyphosate drift was simulated by direct application at 12.5% of the recommended label rate to non-GR corn (Zea mays L.) at …
Abstract: Bt crops are one of the most commonly used genetically modified crops worldwide. Bt crops contain a gene that is derived from the bacteria Bacillus thuringiensis, which produces the Cry1Ab toxin. Bt corn that contains the Cry1Ab toxin is used throughout the Midwest United States to control crop pests such as the European corn …
Abstract: Bt corn has been genetically modified to express the Cry1Ab protein of Bacillus thuringiensis to kill lepidopteran pests. Fluorescence microscopy and staining with toluidine blue indicated a higher content of lignin in the vascular bundle sheaths and in the sclerenchyma cells surrounding the vascular bundle in all ten Bt corn hybrids, representing three different …
Text: We agree with Obrycki et al. (2001) that a broad-based ecological approach for new pest management technologies is desirable, but we unanimously and strongly disagree with some of their assumptions and conclusions about Bt corn. Bt corn is corn that has been genetically engineered to produce insecticidal proteins from the bacterium Bacillus thuringiensis. Because …
Abstract: Genetically modified corn crops and suspensions of Bacillus thuringiensis (Bt) are currently used to control pest infestations of insects of the Lepidoptera family. For this purpose, the cry1Ab gene coding for protein δ-endotoxin derived from B. thuringiensis kurstaki (Btk), which is highly toxic to these insects, was inserted and expressed in corn. The aims …
Abstract: Genetically modified (GM) plants expressing insecticidal traits offer a new strategy for crop protection. GM-corn contains Bacillus thuringiensis (Bt) genes producing delta endotoxins in the whole plant. Diet can influence the characteristics of the gastrointestinal tract altering its function and structure. The aim of this study was to evaluate the effect of GM-corn on …
Abstract: The purpose of this study was to examine the contamination of cry1 and cry1Ab genes from Bacillus thuringiensis and transgenic corn in feral freshwater mussels collected from sites located in proximity of corn fields. In addition, mussels were transplanted for 2 months to a site in the Huron River, upstream to the Richelieu River, …
Abstract: Herbicide spray drift is a major concern in the application of agricultural herbicides. In Mississippi, many corn, soybean, and cotton fields are located in close proximity,thus herbicides used in one crop may contact non-target crops by drift. The use of transgenic crops in agriculture has increased dramatically over the past few years. Transgenic crops …
Abstract: The effects of cotton–corn rotation and glyphosate use on levels of soil-borne Aspergillus flavus, aflatoxin and fumonisin contamination in corn and cotton seed were determined during 2002–2005 in Stoneville, Mississippi (USA). There were four rotation systems (continuous cotton, continuous corn, cotton–corn and corn–cotton) for both glyphosate-resistant (GR) and non-GR cultivars–herbicide system arranged in a …
Abstract: Studies were conducted at three locations in North Carolina in 2004 to evaluate density-dependent effects of glyphosate-resistant (GR) corn on GR cotton growth and lint yield. GR corn was taller than GR cotton as early as 25 d after planting, depending on location. A GR corn density of 5.25 plant/m of crop row reduced …
Abstract: In recent years, corn crop is produced extensively as first and second product in Kahramanmaraş the pests formed European corn borer (Ostrinia nubilalis Hübner) and the stem corn borer (Sesamia nonagrioides Lef.), causes the loss of product per year, average 10-20 % rate. In particularly, this crop loss is observed from the fields which …
