Tolerant Oilseed Rape Research Articles

Nitrogen and sulphur requirements of shattering tolerant canola oilseed rape (Brassica napus L.) under varied plant population

The study was conducted during rabi 2018-19 to study about the row spacing, nitrogen and sulphur requirements of shattering tolerant oilseed rape. Row spacing of 30 cm resulted in 12.7 and 12.6 % higher seed (2819 kg/ha) and oil (1066 kg/ha) yield than 45 cm row spacing. Application of 100 kg/ha of N significantly increased the seed yield by 11.8% and oil yield by 11.9% over 75 kg/ha of N. Application of 40 kg/ha of S increased the seed and oil yield by 3.8% and 4.5%, respectively over 20 kg/ha of applied S. Interactions between different treatments for different traits were non-significant.

Assessment of new scientific elements supporting the prolongation of prohibition of the placing on the market of genetically modified oilseed rape GT73 for food and feed purposes in Austria

Assessment of new scientific elements supporting the prolongation of prohibition of the placing on the market of genetically modified oilseed rape GT73 for food and feed purposes in Austria

Assessment of new scientific elements supporting the prolongation of prohibition of the placing on the market of genetically modified oilseed rape Ms8, Rf3 and Ms8×Rf3 for food and feed purposes in Austria

Assessment of new scientific elements supporting the prolongation of prohibition of the placing on the market of genetically modified oilseed rape Ms8, Rf3 and Ms8×Rf3 for food and feed purposes in Austria

AN OPERATING MODEL FOR THE ENVIRONMENTAL RISK ASSESSMENT APPLIED TO ITALIAN SITES OF COMMUNITY IMPORTANCE: IDENTIFICATION OF POTENTIAL EFFECTS ON SOIL

The fast development of agro-biotechnologies asks for a harmonized approach in risk analysis of GMOs releases. An Italian experts group has elaborated an operating model for the environmental risk assessment (OMERA) based on the assumption that the occurring of a risk is related to the presence of four components: source, diffusion factors, dispersal routes, receptors. This model has been further developed to become a Decision Supporting System based on Fuzzy logic (FDSS) to assessors and notifiers. It is a web based Questionnaire that conducts the user through a decision tree from the source to the receptors and leads to the identification and assessment of the risks. The FDSS has been tested on case studies, simulating, as source, herbicide tolerant oilseed rape and insect resistant maize. The resulting identified potential effects on soil are changes to structure and microbial diversity.

Scientific Opinion on application (EFSA‐GMO‐NL‐2010‐87) for the placing on the market of genetically modified herbicide tolerant oilseed rape GT73 for food containing or consisting of, and food produced from or containing ingredients produced from, oilseed rape GT73 (with the exception of refined oil and food additives) under Regulation (EC) No 1829/2003 from Monsanto

This scientific opinion is a risk assessment for the placing on the market of the genetically modified (GM) herbicide-tolerant oilseed rape (OSR) GT73 for food containing or consisting of, and food produced from or containing ingredients produced from, OSR-GT73. OSR-GT73 contains a single insert consisting of the goxv247 and CP4 epsps expression cassettes. Both proteins confer tolerance against glyphosate-based-herbicides. Bioinformatic analyses of inserted DNA and flanking regions did not raise safety concerns. Levels of CP4 EPSPS and GOXv247 proteins in OSR-GT73 were analysed and the stability of the genetic modification was demonstrated. No biologically relevant differences were identified in the compositional/agronomic/phenotypic characteristics of OSR-GT73 compared with its conventional counterpart, except for the newly expressed proteins. No indication of potential concerns over the safety of the newly expressed CP4-EPSPS and GOXv247 proteins or the occurrence of unintended effects were identified in either OSR-GT73 pollen/pollen-containing dietary supplements or the adventitious presence of trace levels of seeds in human foods. An equivalent assessment with isolated seed protein could not be made because of the lack of availability of relevant consumption and safety data. There are no indications of increased establishment and spread of feral OSR-GT73 plants, or of hybridising wild relatives, unless exposed to glyphosate-based-herbicides. Potential interactions of feral plants with the biotic/abiotic environment do not raise concerns. Environmental risks of horizontal gene transfer into bacteria were not identified. The monitoring plan and reporting intervals are in line with the intended uses. The environmental risk assessment of OSR-GT73 did not identify any safety concerns, in the context of its intended uses. While the Panel is not in a position to conclude on the safety of OSR pollen as such, it concludes that the genetic modification in OSR-GT73 does not constitute an additional health risk if OSR-GT73 pollen were to replace non-GM OSR pollen.

Surveying the occurrence of subspontaneous glyphosate-tolerant genetically engineered Brassica napus L. (Brassicaceae) along Swiss railways

BackgroundRailway tracks represent a highly interlinked habitat with numerous possibilities for accidental entry of oilseed rape due to seed spill during transportation. Moreover, glyphosate is regularly employed to control the vegetation, increasing the possibility of establishment for plants resistant to it. We surveyed the presence of genetically engineered glyphosate tolerant oilseed rape (Brassica napus) with a focus on the most important Swiss railway stations. Our objective was to detect accidental establishment of transgenic plants, since Switzerland does not import nor cultivate transgenic oilseed rape.ResultsSeventy-nine railway areas were sampled in Switzerland and the Principality of Liechtenstein, and the feral presence of oilseed rape was detected in 58 of them. A total of 2403 individuals were tested for genetic modification using commercially available immunologic test kits. In four localities, one located in Lugano and three in the area of Basel, a total of 50 plants expressing the CP4 EPSPS protein were detected. In two of the localities, survival of herbicide applications was observed. The populations were probably introduced through contaminated seed spills from freight trains, or during the transfer of goods from cargo ships to trains.ConclusionsRailways represent an ideal system for herbicide resistant transgenic plants to establish and spread as a result of high selective pressure in favour of herbicide resistance with consequent increased difficulties to keep the infrastructure free of weeds. Crop-to-wild gene flow can occur as several sexually compatible species which are congeneric or in allied genera to oilseed rape were found growing sympatrically. Moreover, the capillary presence of railways in the agricultural landscape provides a putative source of contamination of GE-free agriculture. Our results suggests that carefully adapted monitoring designs may be set in order to detect introduction events that can lead to rapid establishment and growing populations as the accepted contamination thresholds are likely to be biologically insufficient to prevent further environmental contamination.

The metabolism of a novel herbicide ZJ0273 in oilseed rape and crickweed

Experiments were conducted to investigate the metabolism of a novel herbicide ZJ0273 in the seedlings of the susceptible crickweed and tolerant oilseed rape. Six metabolites of ZJ0273 were identified in crickweed seedlings, compared to 8 metabolites in oilseed rape. Among these metabolites, the metabolite M7, with the chemical name of 2-(4,6-dimethoxypyrimidin-2-yloxy) benzoic acid, was found to be the most herbicidally effective molecule with significant inhibition to acetolactate synthase. The differences in the amount and rate of ZJ0273 transformation to M7, and its metabolic detoxification, contributed to the primary mechanism of herbicidal selectivity of ZJ0273.

Feral genetically modified herbicide tolerant oilseed rape from seed import spills: are concerns scientifically justified?

One of the concerns surrounding the import (for food and feed uses or processing) of genetically modified herbicide tolerant (GMHT) oilseed rape is that, through seed spillage, the herbicide tolerance (HT) trait will escape into agricultural or semi-natural habitats, causing environmental or economic problems. Based on these concerns, three EU countries have invoked national safeguard clauses to ban the marketing of specific GMHT oilseed rape events on their territory. However, the scientific basis for the environmental and economic concerns posed by feral GMHT oilseed rape resulting from seed import spills is debatable. While oilseed rape has characteristics such as secondary dormancy and small seed size that enable it to persist and be redistributed in the landscape, the presence of ferals is not in itself an environmental or economic problem. Crucially, feral oilseed rape has not become invasive outside cultivated and ruderal habitats, and HT traits are not likely to result in increased invasiveness. Feral GMHT oilseed rape has the potential to introduce HT traits to volunteer weeds in agricultural fields, but would only be amplified if the herbicides to which HT volunteers are tolerant were used routinely in the field. However, this worst-case scenario is most unlikely, as seed import spills are mostly confined to port areas. Economic concerns revolve around the potential for feral GMHT oilseed rape to contribute to GM admixtures in non-GM crops. Since feral plants derived from cultivation (as distinct from import) occur at too low a frequency to affect the coexistence threshold of 0.9% in the EU, it can be concluded that feral GMHT plants resulting from seed import spills will have little relevance as a potential source of pollen or seed for GM admixture. This paper concludes that feral oilseed rape in Europe should not be routinely managed, and certainly not in semi-natural habitats, as the benefits of such action would not outweigh the negative effects of management.

Quantifying the effect of buffer zones, crop areas and spatial aggregation on the externalities of genetically modified crops at landscape level

The development of genetically modified (GM) crops has led the European Union (EU) to put forward the concept of ‘coexistence’ to give farmers the freedom to plant both conventional and GM varieties. Should a premium for non-GM varieties emerge in the market, ‘contamination’ by GM pollen would generate a negative externality to conventional growers. It is therefore important to assess the effect of different ‘policy variables’ on the magnitude of the externality to identify suitable policies to manage coexistence. In this paper, taking GM herbicide tolerant oilseed rape as a model crop, we start from the model developed in Ceddia et al. [Ceddia, M.G., Bartlett, M., Perrings, C., 2007. Landscape gene flow, coexistence and threshold effect: the case of genetically modified herbicide tolerant oilseed rape ( Brassica napus). Ecol. Modell. 205, pp. 169–180] use a Monte Carlo experiment to generate data and then estimate the effect of the number of GM and conventional fields, width of buffer areas and the degree of spatial aggregation (i.e. the ‘policy variables’) on the magnitude of the externality at the landscape level. To represent realistic conditions in agricultural production, we assume that detection of GM material in conventional produce might occur at the field level (no grain mixing occurs) or at the silos level (where grain mixing from different fields in the landscape occurs). In the former case, the magnitude of the externality will depend on the number of conventional fields with average transgenic presence above a certain threshold. In the latter case, the magnitude of the externality will depend on whether the average transgenic presence across all conventional fields exceeds the threshold. In order to quantify the effect of the relevant ‘policy variables’, we compute the marginal effects and the elasticities. Our results show that when relying on marginal effects to assess the impact of the different ‘policy variables’, spatial aggregation is far more important when transgenic material is detected at field level, corroborating previous research. However, when elasticity is used, the effectiveness of spatial aggregation in reducing the externality is almost identical whether detection occurs at field level or at silos level. Our results show also that the area planted with GM is the most important ‘policy variable’ in affecting the externality to conventional growers and that buffer areas on conventional fields are more effective than those on GM fields. The implications of the results for the coexistence policies in the EU are discussed.

Regulating coexistence in Europe: Beware of the domino-effect!

In the literature spatial coexistence of genetically modified (GM) and non-GM crops is often regarded as a technical challenge, depending on spatial pollen dispersal and cross-pollination, temporal and spatial distribution and interaction of crops, separation distances and practical measures, but the interaction between economic incentives and costs of coexistence is poorly studied. Europe is currently struggling to implement coherent coexistence regulations in all EU Member States. Since the publication of the European Commission's guidelines in 2003, some Member States have developed, and others are still developing, a diversity of ex ante regulations and ex post liability rules on the coexistence of GM and non-GM crops. In this article, our attention is drawn to ex ante regulations. More specifically, we polarize two alternative ways of regulating spatial coexistence, i.e. rigid minimum distance rules, imposed on GM crop production, versus flexible segregation measures such as buffer zones, leaving more freedom of negotiation between neighboring farmers. We conduct simulations with the software ArcView® on a GIS dataset of a hypothetical case of GM herbicide tolerant oilseed rape cultivation in Central France. Our findings show that rigid coexistence rules, such as large distance requirements, may impose a severe burden on GM crop production in Europe. These rules are not proportional to the farmers' basic economic incentives for coexistence and hence not consistent with the objectives of the European Commission. More alarming, we show that in densely planted areas a domino-effect may occur, a theoretical possibility ignored in the literature. This effect raises coexistence costs and even adds to the non-proportionality of rigid coexistence regulations. Instead, we show that flexible measures would be preferable since they are proportional to the economic incentives for coexistence and, hence, less counterproductive for European agriculture.

Landscape gene flow, coexistence and threshold effect: The case of genetically modified herbicide tolerant oilseed rape ( Brassica napus)

Globally there have been a number of concerns about the development of genetically modified crops many of which relate to the implications of gene flow at various levels. In Europe these concerns have led the European Union (EU) to promote the concept of ‘coexistence’ to allow the freedom to plant conventional and genetically modified (GM) varieties but to minimise the presence of transgenic material within conventional crops. Should a premium for non-GM varieties emerge on the market, the presence of transgenes would generate a ‘negative externality’ to conventional growers. The establishment of maximum tolerance level for the adventitious presence of GM material in conventional crops produces a threshold effect in the external costs. The existing literature suggests that apart from the biological characteristics of the plant under consideration (e.g. self-pollination rates, entomophilous species, anemophilous species, etc.), gene flow at the landscape level is affected by the relative size of the source and sink populations and the spatial arrangement of the fields in the landscape. In this paper, we take genetically modified herbicide tolerant oilseed rape (GM HT OSR) as a model crop. Starting from an individual pollen dispersal function, we develop a spatially explicit numerical model in order to assess the effect of the size of the source/sink populations and the degree of spatial aggregation on the extent of gene flow into conventional OSR varieties under two alternative settings. We find that when the transgene presence in conventional produce is detected at the field level, the external cost will increase with the size of the source area and with the level of spatial disaggregation. On the other hand when the transgene presence is averaged among all conventional fields in the landscape (e.g. because of grain mixing before detection), the external cost will only depend on the relative size of the source area. The model could readily be incorporated into an economic evaluation of policies to regulate adoption of GM HT OSR.

Determination of inorganic and organic anions in xylem saps of two contrasting oilseed rape ( Brassica juncea L.) varieties: Roles of anions in long-distance transport of cadmium

By optimizing chromatographic conditions of an ion chromatographic system, we identified and measured the major inorganic and organic anions (chloride, nitrate, malate, sulfate, phosphate and citrate) in the xylem saps of two contrasting tolerant oilseed rape ( Brassica juncea L.) varieties (the high Cd-accumulating genotype Xikou Huazi and the low Cd-accumulating genotype Liangting Huazi). Cadmium concentrations in xylem saps were determined by graphite furnace atomic absorption spectrometry. By analyzing the relationship between anion and cadmium concentrations, we considered that the relatively low phosphate concentrations in Xikou Huazi xylem saps might relate to the relatively high xylem transport of Cd for this genotype, and malate in oilseed rape xylem saps seemed to participate in the long-distance Cd translocation process. Our work might not only be very useful for understanding the mechanisms of Cd hyperaccumulation for Xikou Huazi, but also very beneficial for future application of Xikou Huazi in phytoremediation.

Persistence of seeds from crops of conventional and herbicide tolerant oilseed rape ( Brassica napus )

A series of rotation experiments at five sites over four years has explored the environmental and agronomic implications of growing herbicide tolerant oilseed rape and sugar beet. This paper reports on the population dynamics of volunteer rape (Brassica napus). The experiments compared four winter oilseed rape (WOSR) cultivars: a conventional cultivar (Apex) and three developmental cultivars either genetically modified (GM) to be tolerant to glyphosate or glufosinate, or conventionally bred to be tolerant to herbicides of the imidazolinone group. Seed losses at harvest averaged 3575 seeds m(-2) but ranged from less than 2000 up to more than 10000 seeds m(-2). There was a rapid decline in seed numbers during the first few months after harvest, resulting in a mean loss of seeds of 60%. In subsequent seasons, the seedbank declined much more slowly at four of the five sites (ca 20% per year) and the models predicted 95% seed loss after approximately 9 years. Seed decline was much faster at the fifth site. There were no clear differences between the four cultivars in either the numbers of seeds shed at harvest or in their subsequent persistence. The importance of the persistence of GM rape seeds, in the context of the coexistence of GM and non-GM crops and the role of good management practices that minimize seed persistence, are discussed.

Potential environmental impacts associated with large-scale herbicide-tolerant GM oilseed rape crops

The Biomolecular Engineering Commission considers that the knowledge acquired in the last three years has provided significant information in reply to the points raised in its review dated 16 February 2001.The Commission has studied the potential environmental impacts associated with large-scale herbicidetolerantGMoilseed rape crops, making a distinction between direct and indirect impacts. Direct impacts stem from the intrinsic properties of herbicide-tolerant GM oilseed rape crops whereas indirect impacts result from practices associated with the farming of these crops.The Commission considers that, in the absence of the use of the herbicide in question in and outside of farmed land, there is no direct environmental risk (development of invasive crops per se) associated with the presence of a herbicide-tolerance gene in oilseed rape (or related species).Nevertheless, since the interest of these tolerant crops lies in the use of the herbicide in question, indirect effects, to varying extents, have been identified and must be taken into account: the use of the herbicide in question, applied to agricultural fields containing the herbicide-tolerant crop could lead to an increase in oilseed rape volunteer populations in crop rotations; the selective pressure exerted by non-specific herbicides (to which the crops have been rendered tolerant) may be very high in cases of continuous and uncontrolled use of these herbicides, and may result in the persistence of rare events such as the reproduction of fertile interspecies hybrids; the change to the range of herbicides used should be conveyed by more effective weed control and, like any change in farming practices, induce indirect effects on the agri-ecosystem, particularly in terms of changes to weeds and the associated animal life. Accordingly, the Biomolecular Engineering Commission recommends a global approach in terms of the large-scale farming of herbicide-tolerant crops that: accounts for the characteristics of the herbicide and its current and future use; accounts for herbicide-tolerant varieties belonging to other species, liable to be farmed in French agriculture in the short term; targets, if applicable, the selection of crop/herbicide combinations according to the constraints associated with French agriculture; coordinates the evaluations conducted on herbicide-tolerant crops and those conducted on herbicides; implements a biovigilance system and its associated resources whenever herbicide-tolerant crop farming is envisaged. Our report highlights the need for the management of any herbicide-tolerant GM oilseed rape crops. Such a management plan must account for the diverse cropping situations, including crop rotations and farming practices. Management should be based on the prior evaluation of situations encountered, the development of measures commensurate with the risks, and a validation of their efficacy through biovigilance.The Biomolecular Engineering Commission considers that the indirect environmental and agronomic impacts associated with current management practices employed for herbicide-tolerant oilseed rape crops can only be determined, in addition to the knowledge acquired, by continuing ongoing experimental studies initiated. Mathematical and computer models – by formalizing complex scenarios that incorporate the functioning of different oilseed rape populations (farmed, spontaneous, volunteer plants) under specific farming practices – enables the simulation of potential impacts and the identification of suitable management measures. Nevertheless, at the present time, the introduction of more extensive farming than that currently practised, or managed progressive introduction, would make it possible to progress in the study of impacts and develop and validate management procedures enabling the limitation of adverse impacts.In the specific case of imports, the Biomolecular Engineering Commission considers that herbicidetolerant GM oilseed rape seed imports for processing and animal feed does not represent additional risks for the environment compared to other oilseed rape varieties on the market. Due to the very low likelihood of the dispersal of tolerant oilseed rape crops from imported seed, the impact of the herbicides used on communication routes is considered to be negligible in the current context. However, in order to supplement the information available on environmental impacts and avert any changes to the current situation, the Commission recommends that a general monitoring plan be implemented in parallel to the introduction of seeds onto the market.Finally, the Biomolecular Engineering Commission considers that biovigilance systems adapted to the various risks should be in place before any farming of commercial herbicide-tolerant varieties is undertaken.The Biomolecular Engineering Commission considers its analysis to be valid for non-selective herbicidetolerant varieties of oilseed rape obtained both by transgenesis and by means of a technique other than transgenesis.

Identifying hazards in complex ecological systems. Part 3: Hierarchical Holographic Model for herbicide tolerant oilseed rape

This paper is the third in a series designed to demonstrate the application of rigorous, systematic hazard identification techniques to ecological systems. Here we use Hierarchical Holographic Modelling to identify the potential ecological hazards associated with the commercial release of herbicide tolerant oilseed rape. Hierarchical Holographic Models decompose complex systems into a series of sub-systems and consider interactions between the components and processes of these sub-systems in order to identify hazards. In this example we considered 1356 potential interactions between the biological, chemical and physical components and processes of the herbicide tolerant oilseed rape environment, and identified 152 potential hazards, grouped into 14 categories. The hazards were subsequently scored for degree of concern and plausibility, and then compared with an equivalent list of hazards generated independently by a checklist approach. The incidence of herbicide tolerant volunteers (and weeds) both on and off the farm had the highest average score of all the ecological hazard categories. The checklist based approach identified or implied 44% of the hazards identified in the Hierarchical Holographic Model, including nine of the ten hazards ranked most important. The checklist approach focussed almost exclusively on the phenotypic and genotypic hazards associated with herbicide tolerant oilseed rape and largely ignored the hazards associated with the circumstances surrounding its use. As a result the checklist identified only 6 out of the 79 potential hazards associated with changes to farming practice. The commercial release of herbicide tolerant oilseed rape will be associated with changes in tillage and the application of post-emergent herbicides. It may also lead to changes in spray schedules of insecticide and fungicide. Many of the environmental hazards identified with these changes are plausible and may warrant further investigation or targeted monitoring.

Rapid and efficient screening of phosphinothricin tolerant oilseed rape (Brassica napus) with a novel germination test

A novel screening test is described for the discrimination of transgenic phosphinothricin tolerant oilseed rape from non transgenic rape seedlings. The method is based on the germination of rape seeds on filter paper soaked with a 0.005% phosphinothricin solution. Under these conditions inhibition of seedling development by the herbicide can be observed after 10 days. The germination test gains an advantage over the routinely used herbicide spraying, because it is rapid, needs little space and allows efficient screening of huge numbers of seeds. The assay has been successfully applied to the screening of different transgenic and non transgenic rapeseed varieties/lines and has been compared to other methods such asBasta® spray test, drop test, ELISA-technique and PCR-amplification of the pat gene. This test allows on one hand large screening programmes to monitor the foreign gene in the environment and on the other quality control of seedlots before market introduction of herbicide tolerant oilseed rape.

Ethametsulfuron Methyl Metabolism and Crop Selectivity in Spring Oilseed Rape ( Brassica napus L.)

Ethametsulfuron methyl (methyl 2-[[[[(4-ethoxy-6-methylamino-1,3,5-triazine-2-yl)amino]carbonyl]amino]sulfonyl]benzoate, formerly DPX-A7881) is a sulfonylurea herbicide for postemergence broadleaf weed control in spring oilseed rape ( Brassica napus L.), including canola varieties. Plant response data are presented demonstrating the tolerance of spring oilseed rape to application of 64 g a. i./ha ethametsulfuron methyl while sensitive weeds including Chenopodium album, Sinapsis arvensis, and Amaranthus retroflexus are controlled at rates of 16 g a. i./ha or lower, under greenhouse conditions. The relative tolerance of different weed species and oilseed rape varieties to this sulfonylurea herbicide is related to the rate at which the compound is metabolized to inactive metabolites. Ethametsulfuron methyl is metabolized with a half-life of 1.2-2.5 hr in tolerant oilseed rape, while sensitive weed species or oilseed rape varieties metabolize this herbicide more slowly, with half-lives ranging from 5 to 14 hr. Metabolites of ethametsulfuron methyl were isolated from canola seedlings and analyzed using thermospray liquid chromatography/mass spectrometry (LC/MS), packed capillary LC/MS, and cochromatography with authentic standards. The major early metabolites are O-desethyl ethametsulfuron methyl, which was confirmed by cochromatography with an authentic reference standard, and N-desmethyl- O-desethyl ethametsulfuron methyl. O-Desethyl ethametsulfuron methyl is herbicidally inactive in whole plant studies and is a poor inhibitor of acetolactate synthase, the target site for sulfonylurea herbicides. Additional data are presented which show that the concentration in foliage of ethametsulfuron methyl applied postemergence to oilseed rape at 30 g a.i./ha declines from an initial value of 890 ppb to less than 0.5 ppb 60 days after treatment, and the total radiolabeled burden is only 5 ppb. Thus, the ability of oilseed rape to rapidly metabolize ethametsulfuron methyl accounts for its tolerance to this herbicide and, along with growth dilution, contributes to an extremely low residue lever 60 days after treatment.