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The genetic modification (GM) of maize to contain proteins that act to control insects has become a widespread agricultural practice. Although the reduction of insect damage to maize ears could potentially increase crop yield, rural small-scale farmers might be reluctant to buy expensive GM seed every season even when the lower fungal infection of the GM maize might also result in health benefits. This study was conducted over 5 years in three districts of northern KwaZulu-Natal, South Africa, to study the Fusarium verticillioides and F. proliferatum infection and fumonisin contamination levels in Bt maize, Roundup- Ready® maize, conventional commercial maize and traditional landrace maize planted by rural farmers following their traditional agricultural practices. Mean Fusarium infection rates varied between 3.0% and 38.3% with large standard deviations. Fusarium infection was not significantly different (p>0.05) between the various genotypes, possibly due to the wide variation in results and low sample numbers. Although the fumonisin results also showed wide variation, the trend of contamination was lower in Bt maize compared to conventional commercial genotypes. The mean fumonisin levels in Bt hybrids were mostly <300 µg/kg, ensuring a safe maize supply in populations consuming maize as a dietary staple. The wide variations in Fusarium and fumonisin levels within each district point to the influence of local agricultural practices, local environmental conditions, and seasonal variations. Reducing exposure to fumonisins in these communities requires both further attention to the possible influence of these factors, as well as the use of appropriate post-harvest strategies. Significance: This study was the first in South Africa to follow rural farmers planting Bt and commercial maize hybrids as well as open-pollinated landrace maize, according to their traditional agricultural practices. The results show that in some instances the Bt maize had the lowest fumonisin levels. [ABSTRACT FROM AUTHOR]

DBN9501 is a new maize transgenic event characterised by being resistance to insects and herbicides. To meet genetically modified (GM)-labeling requirements and monitor the unintended release of genetically modified organisms (GMOs), developing a creditable and applicable method for identifying and quantifying GM events is essential. Herein we developed an event-specific method and validated it through inter-laboratory ring trials using blind samples. The limit of detection (LOD) and limit of quantification (LOQ) of copy number ratio were confirmed at 0.05% and 0.1%, respectively. The quantitative bias ranged from -3.52 to 10.38%, and the relative standard deviation (RSD) of the method was < 25%. Furthermore, the expanded uncertainty for the blind samples S1 − S5 was 0.22%, 0.10%, 0.05%, 0.03%, and 0.02%. These results demonstrated that the event-specific quantitative PCR method could identify and quantify GM DBN9501 for further routine lab analysis. [ABSTRACT FROM AUTHOR]

The genetic modification (GM) of maize to contain proteins that act to control insects has become a widespread agricultural practice. Although the reduction of insect damage to maize ears could potentially increase crop yield, rural small-scale farmers might be reluctant to buy expensive GM seed every season even when the lower fungal infection of the GM maize might also result in health benefits. This study was conducted over 5 years in three districts of northern KwaZulu-Natal, South Africa, to study the Fusarium verticillioides and F. proliferatum infection and fumonisin contamination levels in Bt maize, Roundup- Ready® maize, conventional commercial maize and traditional landrace maize planted by rural farmers following their traditional agricultural practices. Mean Fusarium infection rates varied between 3.0% and 38.3% with large standard deviations. Fusarium infection was not significantly different (p>0.05) between the various genotypes, possibly due to the wide variation in results and low sample numbers. Although the fumonisin results also showed wide variation, the trend of contamination was lower in Bt maize compared to conventional commercial genotypes. The mean fumonisin levels in Bt hybrids were mostly

Genetically modified (GM) maize is one of the earliest GM crops to have achieved large-scale commercial cultivation globally, and it is of great significance to excel in the development and implementation of safety policy regarding GM, and in its technical oversight. This article describes the general situation regarding genetically modified maize, including its varieties, applications, relevant laws and regulations, and so on. From a technical point of view, we summarize and critically analyze the existing methods for detecting nucleic acid levels in genetically modified maize. The nucleic acid extraction technology used for maize is explained, and the introduction of traditional detection techniques, which cover variable-temperature and isothermal amplification detection technology and gene chip technology, applications in maize are described. Moreover, new technologies are proposed, with special attention paid to nucleic acid detection methods using sensors. Finally, we review the current limitations and challenges of GM maize nucleic acid testing and share our vision for the future direction of this field. [ABSTRACT FROM AUTHOR]

Genetically modified (GM) technology is of great significance for increasing crop production, protecting biodiversity, and reducing environmental pollution. However, with the frequent occurrence of safety events regarding GM foods, more and more disputes have arisen over the potential safety of transgenic technology. It is particularly necessary to find a fast and accurate method for transgenic product identification. In this research, mid-infrared spectroscopy, coupled with chemometric methods, was applied to discriminate GM maize from its non-GM parent. A total of 120 GM maize and 120 non-GM maize samples were prepared, and the spectral information in the range of 400–4000 cm−1 was collected. After acquiring the spectra, wavelet transform (WT) was used to preprocess the data, and k-means was carried out to split all samples into calibration and prediction sets in the ratio of 2:1. Principal component analysis (PCA) was then conducted to qualitatively distinguish the two types of samples, and an apparent cluster was observed. Since the full spectrum covered a large amount of data and redundant information, we adopted the successive projections algorithm (SPA) to select optimal wavelengths for further analysis. Chemometrics, including partial least squares-discriminant analysis (PLS-DA), the k-nearest neighbor algorithm (KNN), and the extreme learning machine (ELM), were performed to establish classification models based on full spectra and optimal wavelengths. The overall results indicated that ELM models based on full spectra and optimal spectra showed better accuracy and reliability, with a 100% recognition rate in the calibration set and a 98.75% recognition rate in the prediction set. It has been confirmed that mid-infrared spectroscopy, combined with chemometric methods, can be a novel approach to identify transgenic maize. [ABSTRACT FROM AUTHOR]

Transgenic technology has been widely applied to crop development, with genetically modified (GM) maize being the world's second-largest GM crop. Despite the fact that rhizosphere bacterial and fungal populations are critical regulators of plant performance, few studies have evaluated the influence of GM maize on these communities. Plant materials used in this study included the control maize line B73 and the mcrylAb and mcry2Ab dual transgenic insect-resistant maize line 2A-7. The plants and soils samples were sampled at three growth stages (jointing, flowering, and maturing stages), and the sampling compartments from the outside to the inside of the root are surrounding soil (SS), rhizospheric soil (RS), and intact root (RT), respectively. In this study, the results of alpha diversity revealed that from the outside to the inside of the root, the community richness and diversity declined while community coverage increased. Morever, the different host niches of maize rhizosphere and maize development stages influenced beta diversity according to statistical analysis. The GM maize line 2A-7 had no significant influence on the composition of microbial communities when compared to B73. Compared to RS and SS, the host niche RT tended to deplete Chloroflexi, Gemmatimonadetes and Mortierellomycota at phylum level. Nitrogen-fixation bacteria Pseudomonas, Herbaspirillum huttiense, Rhizobium leguminosarum, and Sphingomonas azotifigens were found to be enriched in the niche RT in comparison to RS and SS, whilst Bacillus was found to be increased and Stenotrophomonas was found to be decreased at the maturing stage as compared to jointing and flowering stages. The nitrogen fixation protein FixH (clusters of orthologous groups, COG5456), was found to be abundant in RT. Furthermore, the pathogen fungus that causes maize stalk rot, Gaeumannomyces radicicola, was found to be abundant in RT, while the beneficial fungus Mortierella hyalina was found to be depleted in RT. Lastly, the abundance of G. radicicola gradually increased during the development of maize. In conclusion, the host niches throughout the soil-plant continuum rather than the Bt insect-resistant gene or Bt protein secretion were primarily responsible for the differential assembly of root-associated microbial communities in GM maize, which provides the theoretical basis for ecological agriculture. [ABSTRACT FROM AUTHOR]

The widespread cultivation of genetically modified (GM) crops has raised concerns for their safety. Here, we evaluated the effects of a GM maize variety expressing the Cry1Ab (14.76 ± 0.87 μg/g FW) and EPSPS proteins (191.55 ± 15.69 μg/g FW) on the life-history traits and gut bacterial community of a non-target arthropod, Locusta migratoria, in the laboratory. We found that GM maize had no significant effect on the survival or body weight of different development stages of L. migratoria. The midgut and hindgut bacterial diversities and compositions were determined using high-throughput sequencing targeting the V3–V4 regions of the 16S rRNA. No significant changes were found in the species diversity or abundance between insects in the GM-fed treatment and the non-GM control. Furthermore, the concentration of Cry1Ab and EPSPS in the gut was determined after digestion of GM maize. Results showed that the contents of Cry1Ab/EPSPS rapidly decreased and were hard to detect after 72 h. Based on the parameters assessed, we can conclude that the GM maize variety examined has no significant adverse effect on L. migratoria. [ABSTRACT FROM AUTHOR]

Genetically modified (GM) maize is one of the earliest GM crops to have achieved large-scale commercial cultivation globally, and it is of great significance to excel in the development and implementation of safety policy regarding GM, and in its technical oversight. This article describes the general situation regarding genetically modified maize, including its varieties, applications, relevant laws and regulations, and so on. From a technical point of view, we summarize and critically analyze the existing methods for detecting nucleic acid levels in genetically modified maize. The nucleic acid extraction technology used for maize is explained, and the introduction of traditional detection techniques, which cover variable-temperature and isothermal amplification detection technology and gene chip technology, applications in maize are described. Moreover, new technologies are proposed, with special attention paid to nucleic acid detection methods using sensors. Finally, we review the current limitations and challenges of GM maize nucleic acid testing and share our vision for the future direction of this field.

Returning straw to the soil is an effective way to improve the soil quality. As genetically modified (GM) crops experience expanded growing scales, returning straw to the soil could also be necessary. However, the impact of GM crop straws on soil safety remains unclear. The environment (including soil types, humidity and temperature) can result in a significant difference in the diversity of soil bacterial communities. Here, we compared the impacts of the straw from Bt maize IE09S034 (IE) and near-isogenic non-Bt maize Zong31 (CK) on soil bacterial community and microbial metabolic activity in three different environments. Sampling was carried out following 6-10 months of decomposition (May, June, July, and August) in three localities in Chinese cities (Changchun, Jinan, and Beijing). Our results showed that Bt maize residues posed no direct impact on soil bacterial communities in contrast to the environment and decomposed time. The microbial functional diversity and metabolic activity showed no significant difference between IE and CK. The results could be a reference for further assessing the effect of Bt maize residues on the soil that promotes the commercialisation of Bt maize IE09S034.

The fall armyworm (FAW) Spodoptera frugiperda, which originated in the Americas, is advancing across China and threatening the nation's maize crops. Currently, one widely used tool for its control is genetically modified (GM) Bacillus thuringiensis (Bt) maize. Sufficient content of Bt protein in appropriate plant parts is crucial for enhancing resistance against insect pests. In this study, we conducted a systematic investigation of Cry1Ab levels in Chinese domestic GM maize DBN9936, which has recently obtained a biosafety certificate, and evaluated its efficacy against FAW. Quantification of expression levels of Cry1Ab, via ELISA, indicated a spatio-temporal dynamic, with significant variation of mean Cry1Ab, ranging from 0.76 to 8.48 μg g−1 FW with the Cry1Ab protein level ranked as: V6–V8 leaf>R1 leaf>R4 leaf>R1 silk>VT tassel>R4 kernel. Among the nine locations, the Cry1Ab levels in DBN9936 of the Xinxiang, Langfang, and Harbin fields were significantly lower than those from Wuhan and Shenyang, and were slightly, but not significantly lower than those from the other four fields. Furthermore, the artificial diet–Cry1Ab mixture and plant tissue feeding bioassays revealed that DBN9936 has high efficacy against FAW. The insecticidal efficacy of different tissues against FAW larvae reached 34–100% with a descending order of lethality as follows: VT leaf>R4 leaf>R1 husk>R1 silk>VT tassel>R4 kernel. Taken together, our results showed that Bt-Cry1Ab maize DBN9936 has potential as a promising strategy to manage FAW.

Teosinte, wild maize relatives originating from Mexico and Central America, emerged as a noxious agricultural weed in France and Spain. In 2016, the European Food Safety Authority (EFSA) issued a technical report that assessed the available scientific information on teosinte for its relevance for the environmental risk assessment (ERA) and risk management (RM) of genetically modified (GM) maize MON810, Bt11, 1507 and GA21 for cultivation. It was concluded that the impact of insect resistance and/or herbicide tolerance in GM teosinte hybrid progeny (potentially acquired through hybridisation between GM maize and teosinte) on target and non‐target organisms, the abiotic environment and biogeochemical cycles would be very low under EU conditions. Following a request of the European Commission, EFSA evaluated whether the ERA conclusions and RM recommendations of EFSA (2016) remain applicable, or require revision in light of new scientific evidence on teosinte that has become available since the publication of EFSA (2016). A protocol was developed to clarify the interpretation of the terms of reference of the mandate and make them operational. The assessment relied on evidence retrieved via an extensive literature search and from reports of the Competent Authorities of France and Spain, and on hearing expert testimonies. A limited collection of 18 publications of varying relevance and quality was retrieved and assessed. Based on this evidence, it is concluded that the ERA conclusions and RM recommendations of EFSA (2016) remain applicable, except those pertaining to the use of glyphosate‐based herbicides on maize GA21 which should be considered under Regulation (EC) No 1107/2009. In infested agricultural areas (especially in regions where maize MON810 is widely grown), weed management measures implemented to monitor, control and/or eradicate teosinte must remain in place, as they will contribute to further reduce the low vertical gene flow potential between GM maize and EU teosinte. [ABSTRACT FROM AUTHOR]

Since 1998, genetically engineered Bt maize varieties expressing the insecticidal Cry1Ab protein (i.e. event MON 810) have been grown in the European Union (EU), mainly in Spain. These varieties confer resistance against the European and Mediterranean corn borer (ECB and MCB), which are the major lepidopteran maize pests in the EU, particularly in Mediterranean areas. However, widespread, repeated and exclusive use of Bt maize is anticipated to increase the risk of Cry1Ab resistance to evolve in corn borer populations. To delay resistance evolution, typically, refuges of non-Bt maize are planted near or adjacent to, or within Bt maize fields. Moreover, changes in Cry1Ab susceptibility in field populations of corn borers and unexpected damage to maize MON 810, due to corn borers, are monitored on an annual basis. After two decades of Bt maize cultivation in Spain, neither resistant corn borer populations nor farmer complaints on unexpected field damage have been reported. However, whether the resistance monitoring strategy followed in Spain, currently based on discriminating concentration bioassays, is sufficiently sensitive to timely detect early warning signs of resistance in the field remains a point of contention. Moreover, the Cry1Ab resistance allele frequency to Bt maize, which has recently been estimated in MCB populations from north-eastern Spain, might exceed that recommended for successful resistance management. To ensure Bt maize durability in Spain, it is key that adequate resistance management approaches, including monitoring of resistance and farmer compliance with refuge requirements, continue to be implemented and are incorporated in integrated pest management schemes. [ABSTRACT FROM AUTHOR]

Abstract Teosinte, wild maize relatives originating from Mexico and Central America, emerged as a noxious agricultural weed in France and Spain. In 2016, the European Food Safety Authority (EFSA) issued a technical report that assessed the available scientific information on teosinte for its relevance for the environmental risk assessment (ERA) and risk management (RM) of genetically modified (GM) maize MON810, Bt11, 1507 and GA21 for cultivation. It was concluded that the impact of insect resistance and/or herbicide tolerance in GM teosinte hybrid progeny (potentially acquired through hybridisation between GM maize and teosinte) on target and non‐target organisms, the abiotic environment and biogeochemical cycles would be very low under EU conditions. Following a request of the European Commission, EFSA evaluated whether the ERA conclusions and RM recommendations of EFSA (2016) remain applicable, or require revision in light of new scientific evidence on teosinte that has become available since the publication of EFSA (2016). A protocol was developed to clarify the interpretation of the terms of reference of the mandate and make them operational. The assessment relied on evidence retrieved via an extensive literature search and from reports of the Competent Authorities of France and Spain, and on hearing expert testimonies. A limited collection of 18 publications of varying relevance and quality was retrieved and assessed. Based on this evidence, it is concluded that the ERA conclusions and RM recommendations of EFSA (2016) remain applicable, except those pertaining to the use of glyphosate‐based herbicides on maize GA21 which should be considered under Regulation (EC) No 1107/2009. In infested agricultural areas (especially in regions where maize MON810 is widely grown), weed management measures implemented to monitor, control and/or eradicate teosinte must remain in place, as they will contribute to further reduce the low vertical gene flow potential between GM maize and EU teosinte.

Summary: Nutritional equivalency feeding studies with diets containing genetically modified grain continue to be required by some regulatory agencies as part of the safety assessment of new events. These studies have long been conducted using broiler chickens, as they are very sensitive to nutritional deficiencies and antinutrients in the diet owing to their very rapid growth rate. A new transgenic maize product containing event DP-2Ø2216-6 (DP202216) with enhanced grain yield potential and an herbicide-tolerance trait has been developed. The nutritional equivalency of grain produced from maize containing this event with conventional grain was evaluated in a 42-D feeding trial with male and female Ross 708 broiler chickens. Broilers consuming diets produced with grain from DP202216 maize plants performed as well and produced similar organ, carcass, and parts yields as broilers consuming diets produced with nontransgenic near-isogenic control grain. In addition, the ranges of observed performance and carcass and organ yield trait values from DP202216 and control groups were similar to the respective ranges observed for broilers fed diets containing nontransgenic commercially available maize grains. Based on these results, it is concluded that grain from DP202216 maize is nutritionally equivalent to grain from nontransgenic near-isogenic maize, consistent with previously published reports on whole-food (where the edible crop tissue is incorporated in the feed) animal feeding studies for other genetically modified events.

The global commercialization of genetically modified (GM) crops has increased the likelihood of feed‐derived transgenic DNA uptake and raised concerns regarding the fate of such DNA fragments in animals consuming a GM diet. The present study applied a novel droplet digital polymerase chain reaction (ddPCR) method to quantitatively detect the concentrations of feed‐derived transgenic (Cry1Ie) and endogenous (rubisco) plant DNA in the livers, intestinal tracts and muscles of zebrafish (Danio rerio) fed GM maize for uantifying feed‐derived DNA in animal tissues as a more sensitive and reliable alternative to qPCR. [ABSTRACT FROM AUTHOR]

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When genetically modified (GM) maize is planted in an open field, it may cross-pollinate with the nearby non-GM maize under certain airflow conditions. Suitable sampling methods are crucial for tracing adventitious GM content. By using field data and bootstrap simulation, we evaluated the performance of common sampling schemes to determine the adventitious GM content in small maize fields in Taiwan. A pollen dispersal model that considered the effect of field borders, which are common in Asian agricultural landscapes, was used to predict the cross-pollination (CP) rate. For the 2009–1 field data, the six-transect (Tsix), JM method for low expected flow (JM[L]), JM method for high expected flow (JM[H]), and V-shaped transect (TV) methods performed comparably to simple random sampling (SRS). Tsix, TV, JM(L), and JM(H) required only 13% or less of the sample size required by SRS. After the simulation and verification of the 2009–2 and 2010–1 field data, we concluded that Tsix, TV, JM(L), and systematic random sampling methods performed equally as well as SRS in CP rate predictions. Our findings can serve as a reference for monitoring the pollen dispersal tendencies of maize in countries with smallholder farming systems. [ABSTRACT FROM AUTHOR]

Nutritional equivalency feeding studies with diets containing genetically modified grain continue to be required by some regulatory agencies as part of the safety assessment of new events. These studies have long been conducted using broiler chickens, as they are very sensitive to nutritional deficiencies and antinutrients in the diet owing to their very rapid growth rate. A new transgenic maize product containing event DP-2Ø2216-6 (DP202216) with enhanced grain yield potential and an herbicide-tolerance trait has been developed. The nutritional equivalency of grain produced frommaize containing this event with conventional grainwas evaluated in a 42-D feeding trialwithmale and female Ross 708 broiler chickens.Broilers consuming diets producedwith grain from DP202216 maize plants performed as well and produced similar organ, carcass, and parts yields as broilers consuming diets produced with nontransgenic near-isogenic control grain. In addition, the ranges of observed performance and carcass and organ yield trait values from DP202216 and control groups were similar to the respective ranges observed for broilers fed diets containing nontransgenic commercially available maize grains. Based on these results, it is concluded that grain from DP202216 maize is nutritionally equivalent to grain fromnontransgenic near-isogenicmaize, consistent with previously published reports onwhole-food (where the edible crop tissue is incorporated in the feed) animal feeding studies for other geneticallymodified events. [ABSTRACT FROM AUTHOR]

In this study, an isothermal paper biosensor, combining single universal primer recombinase polymerase amplification (SUP-RPA) and the lateral flow technique was developed for the multiplex detection of genetically modified maize (GMM). In pre-amplification stage, the event-specific primers contain a universal sequence at the 5' end, with a biotin-labeled deoxycytidine triphosphate (dCTP) deoxynucleotide providing additional amplification, which improves their amplification ability and ensures consistent multiplex amplification efficiency. In the signal recognition strategy, the SUP-RPA products are identified visually using the lateral flow biosensor (LFB) through dual hybridization. The accumulation of gold nanoparticles (AuNPs) produces a characteristic red band. Through this biosensor, a limit of detection of at least 50 copies was achieved, which is sensitive enough to detect MON810, MON863 and MON89034 simultaneously. The entire process of analysis was completed within 30 min and without any large-scale instrumentation. This biosensor, therefore, provides a novel rapid and portable multiple detection method for point-of-care applications, especially genetically modified organism (GMO) event-specific detection. Image 1 • Construction of a single universal primer multiplex RPA-based lateral flow biosensor (SUP-RPA-LFB) for point-of-care detection. • Development of a multiplex detection strategy based on RPA isothermal amplification. • Single universal primer maintains the consistency of efficiency in multiple-target situations. • Temperature-driven dimer subtraction technique improves specificity. • SUP-RPA-LFB shows high sensitivity and selectivity for DNA detection. [ABSTRACT FROM AUTHOR]

This study aimed to detect genetically modified maize (GMM) in seeds of eleven imported maize hybrids grown in Jordan. We used promoter 35 S and T-nos terminator for general screening of transgenic materials. Conventional PCR detected the specific events for the screening of Bt 11, MON810, and Bt176 events. Seeds of eleven maize hybrids samples showed a positive response to the 35 S promoter; nine out of eleven showed a positive response for T-nos terminator. Bt11 event was the most used in GMM seeds, where seven out of eleven samples showed positive results. Two out of eleven hybrids showed the presence of the Bt176 event; however, MON810 not detected in any of the tested hybrids. We studied the Bt11 event in imported GMM seeds in Jordan for the first time, reinforcing the need for a mandatory labeling system and a valid simple qualitative method in routine analysis of GMCs. [ABSTRACT FROM AUTHOR]

The commercialization of RNA‐based agricultural products requires robust ecological risk assessments. Ecological risk is operationally defined as a function of exposure and adverse effects. Information on the environmental fate of RNA‐based plant‐incorporated protectants is essential to define routes and duration of exposure to potentially sensitive nontarget organisms. Providing these details in problem formulation helps focus the ecological risk assessment on the relevant species of concern. Postharvest plant residue is often considered to be the most significant route of exposure for genetically modified crops to adjacent aquatic environments. Previous studies have shown that DvSnf7 RNA from SmartStax PRO maize dissipates rapidly in both terrestrial and aquatic environments. Although these studies suggest that direct exposure to DvSnf7 RNA is likely to be low, little is known regarding the fate of DvSnf7 RNA produced in plants after entering an aquatic environment. This exposure scenario is relevant to detritivorous aquatic invertebrates that process conditioned maize tissues that enter aquatic environments. To assess potential exposure to shredders, dissipation of DvSnf7 RNA expressed maize tissue was evaluated following immersion in microcosms containing sediment and water. Concentrations of DvSnf7 RNA in the tissue were measured over a duration of 21 d. The DvSnf7 RNA dissipated rapidly from immersed maize tissue and was undetectable in the tissues after 3 d. Concentrations of DvSnf7 RNA found in tissue as well as calculated water column concentrations were below levels known to elicit effects in a highly sensitive surrogate species, supporting the conclusion of minimal risk to aquatic nontarget organisms. Environ Toxicol Chem 2020;39:1032–1040. © 2020 SETAC [ABSTRACT FROM AUTHOR]

The implementation of genetically modified organism (GMO) safety management and labeling system requires standardized testing methods and GMO testing standard substances, which guarantee the acquirement of accurate, reliable and comparable testing results. GMO maize T25 was approved for import as processing raw material in China. In order to strengthen the supervision of T25, the present work took the T25 matrix standard substance as the research object and established the digital PCR method. Eight laboratories were selected and the digital PCR combined quantitative determination were adopted. The results showed that the T25/Adhl dual digital PCR system had good amplification specificity. Stable and reliable detection results could be obtained between 100 and 10 000 copies ⋅ µL-1 of the initial template. The method of T25/Adhl dual digital PCR was proved to be accurate and reliable through multi-laboratory collaborative evaluation. The quantitative value of T25 matrix standard substance was 1.001 2 and the relative uncertainty was 0.001 6. It was established that T25/Adhl dual digital PCR method could be used for the quantitative evaluation of genetically modified corn T25, which provided material basis and technical guarantee for the quantitative detection of genetically modified components. [ABSTRACT FROM AUTHOR]

Cytoplasmic male sterility (CMS) allows efficient biological confinement of transgenes if pollen-mediated gene flow has to be reduced or eliminated. For introduction of CMS maize in agricultural practice, sufficient yields comparable with conventional systems should be achieved. The plus-cultivar-system in maize offers a possibility for biological confinement together with high and stable yields whereas pollinator amount and distribution within the CMS crop is crucial. The aim of this EU-funded study was to identify the best proportion (10, 15, and 20%) and spatial arrangement (inserted rows, mixed seeds) of the pollinator within the CMS maize cultivar under field conditions in the Czech Republic, in Germany and in Spain. In Germany and in the Czech Republic, a pollinator proportion of 10% produced significantly lower yield than the treatments with a pollinator proportion of 15% and 20%. Differences in yield between row and mix arrangements were not detected. No differences between the tested arrangements occurred in Spain. With respect to practical conditions, a pollinator proportion of 15% can be recommended for achieving a satisfactory yield. CMS maize cultivar released no or merely a small amount of pollen and self-pollinated plants developed no or only a small number of kernels indicating that currently recommended isolation distances between genetically modified (GM) and non-GM fields can be substantially shortened if the CMS confinement tool is used.

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Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fall armyworm (FAW), Spodoptera frugiperda , is one of the most destructive pests of maize in warm regions of the Americas and a severe invasive species in Africa. Considering the armyworm management and its ability to develop resistance rapidly to synthetic insecticides and Bacillus thuringiensis (Bt) toxins, we assessed the response of field and laboratory populations of FAW to Bt maize hybrids and Bt-based bioinsecticides. In the laboratory, FAW neonates from two Bt-resistant colonies and three field-collected populations were fed foliage of Bt maize or Bt bioinsecticides incorporated into artificial diet, and larval survival and biomass were recorded after seven days. Larvae of the two laboratory colonies resistant to Bt maize producing Cry1 or Cry2 toxins had high larval survival rates on foliage of specific Bt maize hybrids (i.e., Cry1F or Cry1A.105 + Cry2Ab). On foliage of the Cry1A.105 + Cry2Ab Bt maize, larvae of one of the field-collected populations had survival rates similar to the Bt-resistant laboratory larvae but had strong growth inhibition. The field-collected larvae had less than 30% survival on foliage of Cry1F maize and larval weights equivalent to those of the Cry1F-resistant colony. In addition, while some larvae survived exposure to formulations of B. thuringiensis kurstaki (i.e., Dipel and Thuricide), the two formulations of B. thuringiensis aizawai (i.e., Agree and Xentari) caused 100% larval mortality in all FAW colonies and the field populations, including the ones showing reduced-susceptibility to Cry1F or Cry1A.105 + Cry2Ab Bt maize. This research shows that there are field populations of FAW with different levels of susceptibility to specific Bt toxins and that resistance to Cry1 and/or Cry2 may or may not reduce the efficacy of certain Bt bioinsecticides against the neonates. • Field-collected FAW varied in survival/growth on Cry1F or Cry1A.105 + Cry2Ab Bt maize. • Bt aizawai killed all larvae in all FAW populations while Bt kurstaki did not. • Cry-toxin resistance may reduce the efficacy of certain Bt bioinsecticides against FAW. [ABSTRACT FROM AUTHOR]

The GMO90+ project was designed to identify biomarkers of exposure or health effects in Wistar Han RCC rats exposed in their diet to 2 genetically modified plants (GMP) and assess additional information with the use of metabolomic and transcriptomic techniques. Rats were fed for 6-months with 8 maize-based diets at 33% that comprised either MON810 (11% and 33%) or NK603 grains (11% and 33% with or without glyphosate treatment) or their corresponding near-isogenic controls. Extensive chemical and targeted analyses undertaken to assess each diet demonstrated that they could be used for the feeding trial. Rats were necropsied after 3 and 6 months. Based on the Organization for Economic Cooperation and Development test guideline 408, the parameters tested showed a limited number of significant differences in pairwise comparisons, very few concerning GMP versus non-GMP. In such cases, no biological relevance could be established owing to the absence of difference in biologically linked variables, dose-response effects, or clinical disorders. No alteration of the reproduction function and kidney physiology was found. Metabolomics analyses on fluids (blood, urine) were performed after 3, 4.5, and 6 months. Transcriptomics analyses on organs (liver, kidney) were performed after 3 and 6 months. Again, among the significant differences in pairwise comparisons, no GMP effect was observed in contrast to that of maize variety and culture site. Indeed, based on transcriptomic and metabolomic data, we could differentiate MON- to NK-based diets. In conclusion, using this experimental design, no biomarkers of adverse health effect could be attributed to the consumption of GMP diets in comparison with the consumption of their near-isogenic non-GMP controls. [ABSTRACT FROM AUTHOR]

LP007-1 is a variety of insect-resistant and herbicide-tolerant maize containing the modified cry1Ab , cry2Ab , vip3Aa and cp4-epsps genes. The food safety assessment of the maize LP007-1 was conducted in Wistar Han RCC rats by a 90-days feeding study. Maize grains from both LP007-1 or its corresponding non-genetically modified control maize AX808 were incorporated into rodent diets at 25% and 50% concentrations by mass and administered to rats (n = 10/sex/group) for 90 days. A commercialized rodent diet was fed to an additional group as the basal-diet group. The diets of all groups were nutritionally balanced. No biologically relevant differences were observed in rats fed with maize LP007-1 compared to rats fed with AX808 and the basal-diet with respect to body weight/gain, food consumption/utilization, clinical signs, mortality, ophthalmology, clinical pathology (hematology, prothrombin time, activation of partial thrombin time, serum chemistry, urinalysis), organ weights, and gross and microscopic pathology. Considering the circumstances of this study, the results provided evidence that LP007-1 maize did not exhibit toxicity in the 90-day feeding study. • A 90-day subchronic feeding study of genetically modified maize LP007-1 in Wistar Han RCC rats, was conducted. • Maize LP007-1 was conferred insect resistance and glyphosate tolerance. • Cry1Ab, cry2Ab, vip3Aa and cp4-epsps, are co-expressed in maize LP007-1. • Maize LP007-1 diets did not produce any adverse effects in rats during the study. • Maize LP007-1 was considered as safe and nutritious as the non-genetically modified maize. [ABSTRACT FROM AUTHOR]

Field trials with the genetic modified (GM) maize stacked hybrid NK603 × MON810 performed in two different locations in the Czech Republic were used for evaluation of genetic diversity of rhizosphere bacterial communities using the terminal restriction fragment length polymorphism. Statistically significant differences in the number of terminal restriction fragments (i.e. bacterial richness) between GM and non-GM maize were not detected. Diversity indices (Gini-Simpson and Shannon’s) revealed higher bacterial diversity in non-GM sample from location Ivanovice na Hané and in the GM maize from location Probluz, but statistical significant differences between GM and non-GM samples were not detected. Additionally, using principal component analysis and cluster analysis, no substantial variation in the composition of bacterial communities between GM and conventional maize were observed but the differences among individual collection sites were recorded.

Genetically modified organisms (GMO) are increasingly gaining acceptance, which has led to an increasing demand for high-throughput methods for their detection. This study describes development of a high-throughput and low-cost multiplex tandem PCR (MT-PCR) assay for the screening of transgenic maize of 14 targets, containing 7 genetically modified (GM) common screening elements, 6 transgenic maize events and a maize reference gene, using SYBR Green I for quantification. The 14-target high-throughput multiplex tandem PCR assay successfully amplified products from single-event samples with a GM maize DNA amount less to 0.001 ng, and displayed high specificity. This assay can efficiently be used for screening GM maize in foods and feeds. [ABSTRACT FROM AUTHOR]

A 90-day rat feeding study was performed to conduct a safety assessment on L4, a multi-gene genetically modified maize, conferring "Bt" insect resistance and glyphosate tolerance. A total of 140 Wistar rats were assigned to seven groups, 10 animals/group/sex, which comprised three genetically modified groups fed diets containing different concentrations of L4, three corresponding non-genetically modified groups fed diets containing different concentrations of zheng58 (parent plants), and a basal diet group fed the standard basal diet for 13 weeks. The fed diets contained L4 and Zheng58 at w/w% percentages of 12.5%, 25.0%, and 50% of the total. Animals were evaluated on some research parameters, including general behaviour, body weight/gain, feed consumption/efficiency, ophthalmology, clinical pathology, organ weights, and histopathology. Throughout the feeding trial, all animals were in good condition. No mortality and no biologically relevant effects or toxicologically significant alterations were observed in the total research parameters of the rats in the genetically modified groups compared with those in the basal diet group or their corresponding non-genetically modified groups. No adverse effects were observed in any of the animals. The results indicated that L4 is as safe and wholesome as conventional, non-genetically modified control maize. • A 90-day rodent feeding study of a genetically modified maize L4, was conducted. • Maize L4 developed, was conferred insect resistance and glyphosate tolerance. • Cry1Ab gene, cry1F gene, and cp4epsps gene, are co-expressed in maize L4. • No treatment-related adverse effects were observed in all treated animals. • Maize L4, is as safe as its corresponding non-genetically modified maize line. [ABSTRACT FROM AUTHOR]

The aim of this article is to contribute to the academic dialogue of policy convergence by examining the direction taken by the policy to label genetically modified maize in the European Union. Considering international harmonisation as the causal mechanism, this article provides a chronological account of policy outputs, understood as directives and regulations related to this policy area. Additionally, there is an analysis of the increase of the degree of policy convergence. Furthermore, different national perspectives on the issue are presented, offering an insight about policy direction in terms of the interaction that governments of member states have between them and with the European Commission. Concomitantly, the direction that policy convergence takes points at strengthening member states’ views of developing stricter rules through time. Subsequently, results demonstrate that policy convergence can appear only with member states’ consent, regardless of the position that regional institutions may have; although they may influence the process to some extent. Nonetheless, this does not mean that the current direction should be taken for granted.

This study was done to examine the rhizobacteria from field grown Genetically Modified (GM) maize and its non-GM counterpart. Rhizospheric soil samples were collected at 30 days after sowing (DAS) and at post-harvest from two experimental fields in Gauteng, South Africa. Total rhizobacteria (cfu/g) in GM and non-GM soil samples was not significantly different across the different media 30 DAS and at post-harvest. Rhizobacterial isolates obtained were biochemically characterized using the analytical profile index. Species of Pseudomonas, Aeromonas, Sphingomonas, Burkholderia, Stenotrophomonas, Achromobacter, Ewingella and Bacillus were screened in vitro for plant growth promoting traits such as, ammonia production, catalase activity, indole acetic acid production, phosphate solubilisation, hydrogen cyanide production and antifungal activity. All the 32 rhizobacterial strains tested in this study were positive for catalase activity, ammonia production and IAA production; 90.6% were positive for phosphate solubilisation, 34.3% for indicate antifungal activity but none for hydrogen cyanide production. These findings contributed to the quest for potential biofertilizers and biocontrol agents for sustainable agriculture.