Conventional Oilseed Rape Research Articles

Molecular characterization of imidazolinone-resistant Brassica rapa × B. napus hybrids.

Herbicide-resistant oilseed rape (Brassica napus) cultivation in our country entails the risk of gene transfer to related wild species. One of these species is the wild turnip (B. rapa), an important weed of winter crops widely distributed in the Pampas region. Despite hybridization risks, Clearfield ® oilseed rape is available in Argentina. In 2008, a B. rapa population, which was sympatric to an imidazolinone-resistant and a conventional oilseed rape cultivar, was located on a farm in the main cropping area of the country. Herbicide-resistant individuals were found in the progeny of this population in a herbicide screening test. Therefore, a molecular characterization using cleaved amplified polymorphic sequence (CAPS) and simple sequence repeat (SSR) markers was conducted on these plants to determine their hybrid nature and to establish the origin of the imidazolinone resistance trait. The results of this study, along with information of field records, confirmed that the resistant plants were first generation interspecific hybrids. Imidazolinone resistance had been effectively transferred from the herbicide-resistant oilseed rape, even in the particular situation of pollen competition. Oilseed rape resistant cultivars are becoming more common in the country. So, considering that seed loss and crop volunteers are common in these species, it is crucial to avoid the dispersion of new resistant weed biotypes as they reduce the effectiveness of chemical control technologies.

Food/Feed and Environmental Risk Assessment of Genetically Modified Glufosinate-tolerant Oilseed Rape MS8, RF3 and MS8 x RF3 for Import, Processing and Feed Uses under Directive 2001/18/EC (Notification C/BE/96/01)

Food/Feed and Environmental Risk Assessment of Genetically Modified Glufosinate-tolerant Oilseed Rape MS8, RF3 and MS8 x RF3 for Import, Processing and Feed Uses under Directive 2001/18/EC (Notification C/BE/96/01)

Food, Feed and Environmental Risk Assessment of Glufosinatetolerant Genetically Modified Oilseed Rape T45 for Food and Feed Uses, Import and Processing Under Regulation (EC) No 1829/2003 (Application EFSA/GMO/UK/2005/25)

Food, Feed and Environmental Risk Assessment of Glufosinatetolerant Genetically Modified Oilseed Rape T45 for Food and Feed Uses, Import and Processing Under Regulation (EC) No 1829/2003 (Application EFSA/GMO/UK/2005/25)

Environmental Risk Assessment of Glufosinate-Tolerant Genetically Modified Oilseed Rape T45 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (Application EFSA/GMO/UK/2005/25)

Environmental Risk Assessment of Glufosinate-Tolerant Genetically Modified Oilseed Rape T45 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (Application EFSA/GMO/UK/2005/25)

Preliminary Environmental Risk Assessment of Genetically Modified Oilseed Rape MON 88302 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (Application EFSA/GMO/BE/2011/101)

Preliminary Environmental Risk Assessment of Genetically Modified Oilseed Rape MON 88302 for Food and Feed Uses, Import and Processing under Regulation (EC) No 1829/2003 (Application EFSA/GMO/BE/2011/101)

Environmental Risk Assessment of Glufosinate-Tolerant Genetically Modified Oilseed Rape MS8, RF3 and MS8 x RF3 for Import, Processing and Feed Uses under Directive 2001/18/EC (Notification C/BE/96/01)

Environmental Risk Assessment of Glufosinate-Tolerant Genetically Modified Oilseed Rape MS8, RF3 and MS8 x RF3 for Import, Processing and Feed Uses under Directive 2001/18/EC (Notification C/BE/96/01)

Competition, reproduction ability, and control possibilities of conventional and Clearfield® volunteer oilseed rape in winter wheat

Three plot field trials (2014–2017) were carried out in Prague. The aim of the study was to evaluate the efficacy of herbicides against volunteers from Clearfield® (CL) and conventional oilseed rape (Brassica napus L.) in winter wheat (Triticum aestivum L.) and to quantify the effect of herbicide and application time on wheat yield. Autumn control (diflufenican, isoproturon, flumioxazin, metribuzin, penoxsulam, florasulam, chlorsulfuron were tested) of volunteer oilseed rape (OSR) was more effective than using the spring herbicide treatments (2,4-D, iodosulfuron, amidosulfuron, tritosulfuron, florasulam), especially against the CL OSR variety. Full control of both CL and conventional OSR was recorded only on plots treated by the combination of metribuzin + diflufenican + flufenacet. The most effective spring herbicide was 2,4-D, but its efficacy (82–95%) depended on the growth stage of OSR and application rate. Efficacy of spring herbicides against CL OSR was lower compared to that against conventional OSR, but there were large differences among tested herbicides. Efficacy of tested ALS inhibitors against volunteer CL OSR ranged between 20% (chlorsulfuron) and 77% (tritosulfuron + florasulam). Seed production of volunteer OSR ranged between 0 and 37,000 seeds m−2 while depending strongly on time of sowing and weather conditions during the autumn and winter. No seed of CL OSR matured on plots treated by metribuzin in autumn or 2,4-D at application rate 377 g ha−1 in spring. Volunteer OSR in competition with winter wheat caused almost 50% wheat yield loss on the untreated check. Although the efficacy of most spring herbicide treatments on conventional OSR was good, the competition effect of OSR on wheat during winter and early spring caused about 0.52–0.86 t ha−1 greater yield loss compared to autumn herbicide treatments.

Effects of Nitrogen Fertilizer on Nitrogen Accumulation, Translocation and Nitrogen Use Efficiency in Rapeseed ( Brassica napus L.)

In this study, five conventional oilseed rape varieties with different oil contents, including Yangyou 6(YY6), Suyou 211(SY211), Ningyou 20(NY20), Zhongshuang 11(ZS11), and Zheyou 50(ZY50) were grown under three N(nitrogen) fertilizer levels: 120(N1), 240(N2), and 360 kg N ha-1(N3) from 2010 to 2012. The effects of N application on N accumulation, N translocation rate and N use efficiency were studied through plant sampling, picking deciduous leaf and measuring dry matter weight, N content and oil content. The results showed that with increasing N application rates yield and total N amount in whole plant increased, and N harvest index(NHI) and N use efficiency for grain production(NUEg) decreased. The N translocation rate in leaf ranged from 76.6% to 80.2%, and there were no significant differences among different N fertilizer levels. The nitrogen translocation rate in stem ranged from 36.0% to 57.6%, and decreased with increasing N application rates. The N proportion of deciduous leaf to whole plant ranged from 14.9% to 20.3%, and increased with increasing N application rates. The N proportion of the beginning of flowering stage to ripening stage was from 75.5% to 90.5%, and increased with increasing N application rates. The effect of N amount at the beginning of flowering stage on yield is significant. N application at earlier stage promotes flower bud differentiation and increases effective pods, resulting in higher yield.

Insights into temperature effects on the fatty acid composition of oilseed rape varieties

Conventional oilseed rape (OSR) and high-oleic low-linolenic (HOLL) varieties were compared for their temperature sensitivity during 10 years of variety testing in Switzerland. A high variability in alpha-linolenic acid (ALA) content among locations and years was noticed for both types of varieties (6.3% to 11.4% for conventional varieties, 2.1% to 4.6% for HOLL ones).Average minimum temperature was registered during seed filling, between 680° and 930° days after the onset of flowering. They ranged from 9.2°C and 17.5°C and were negatively correlated to ALA content in the seeds at harvest. Additionally to lower ALA contents, HOLL varieties had a smaller response to temperature, as compared to conventional cultivars. When studying each variety independently, small but significant differences appeared among varieties of the same group (HOLL or conventional). Among conventional varieties, differences were observed only in oleic acid desaturation, whereas linoleic acid desaturation efficiency was similar for the studied cultivars. Conversely, in HOLL varieties, linoleic acid desaturation was reduced by mutations and not affected by temperature, resulting in lower ALA content and a lower sensitivity to temperature. Each OSR variety could be characterized by the regression parameters for their specific response to minimum temperature in the adequate period, with two distinct groups for conventional and HOLL varieties.A single model for each variety group was built to predict ALA content at harvest, based simply on minimal temperature during the period. The model was then tested on an independent data set. Combinations with the model BRASNAP-PH to predict onset of flowering made it possible to simulate ALA content without field observations, knowing only sowing date and meteorological data. A sensitivity analysis was performed to determine which precision was required on flowering date and the importance of knowing cultivar characteristics.Our results showed that ALA content prediction was possible, although flowering date was only estimated with a precision of 3 days. In spite of differences among varieties for their temperature sensitivity (R2 varying from 0.39 to 0.89 among tested varieties), a general equation can give a satisfying prediction for conventional varieties within the observed range of temperature, (y=−0.41x+13.7, with x=minimum temperature registered during the sensitive period, R2=0.52, p<0001). Therefore, using this general model could be used to test the potential of a new production site or assess the quality variability upon time or among different locations

Crop, field boundary, productivity and disturbance influences on ground beetles (Coleoptera, Carabidae) in the agroecosystem

Ground beetles were sampled in nine crops and four field boundary types on a split conventional/organic farm in northern England in the five years 2005–2009. Multivariate analyses indicated that a combination of crop type, management and boundary type influenced ground beetle species and group activity. Short vegetation boundaries with bare ground had similar activity, mainly of small species, to that in organic arable crops, contrasting with activity in conventional arable and more densely vegetated boundaries. Large, medium-sized, herbivorous and Collembola feeding species all had considerable activity in oilseed rape and activity was generally greatest in conventional arable crops but least in conventional grass. Disturbance and productivity estimations provided basic insights into ground beetle activity. Most small and medium-sized species were found in areas with low productivity but high and low disturbance, respectively. Large and Collembola feeding species were most active in highly productive areas with medium and low disturbance whilst most herbivorous species preferred medium values of both drivers. In crops, species richness was greatest in organic beans and conventional oilseed rape and lowest in conventional grass. There were more species in short vegetation boundaries than in more densely vegetated field edges. There may be potential for the use of productivity and disturbance estimations in the provision of ecosystem services, especially in assessing the conditions required to optimise ground beetle activity for pest control.

Molecular marker-based identification of oilseed rape volunteers with different secondary dormancy levels in oilseed rape fields

Pod dehiscence of oilseed rape (OSR) occurs before and during harvest, resulting in seed losses and in seed persistence in the soil for several years. Persisting seeds can emerge as volunteers in subsequent crops. Volunteers with deviating traits and especially genetically modified (GM) oilseed rape volunteers can impair the product quality of an oilseed rape crop. Under experimental field conditions seed persistence and volunteer abundance were found to be efficiently controlled by delayed post-harvest tillage and selection of cultivars with low secondary seed dormancy.To investigate the long-term factors affecting volunteer abundance in farmer-managed fields, an on-farm survey was carried out in winter oilseed rape fields at different locations in Germany, using artificial sowing gaps as one method to detect putative volunteers. Molecular marker analysis (ISSR-PCR), which was performed for 11 out of 31 fields, confirmed that most of the plants identified within sowing gaps were indeed volunteers. In fields with low OSR cropping frequency high percentages of volunteers could be assigned to previously cultivated varieties. Results indicate that seeds of varieties with high secondary dormancy (HD) persist in the fields for longer times and in larger numbers than seeds of varieties with low secondary dormancy. However, cultivation of HD varieties did not necessarily result in high volunteer abundance, as location and management factors have further impact on long-term seed survival. Nevertheless, with respect to GM oilseed rape cultivation proper variety selection will be an important means to assure co-existence with conventional oilseed rape.

Crop management for optimal low-linolenic rapeseed oil production—Field experiments and modelling

Oil of conventional oilseed rape (OSR) varieties with 7–10% alpha-linolenic acid content (LAC) might oxidize when heated, resulting into an unpleasant odor. Varieties with low (around 3%) LAC have been bred to provide industries with a new raw material for frying media production. However, high-oleic low-linolenic (HOLL) OSR quality could be compromised by conventional OSR through pollen flow or volunteers. Both nearby fields and volunteers of conventional OSR growing in the HOLL field or in its margins could thus be the cause of a reduced quality. Crop management practices such as regional field pattern, crop rotation, weed control and soil tillage might be decisive. The GeneSys model was initially developed to quantify the effects of cropping systems on gene flow between genetically-modified (GM) and non-GM crops. In this work, it was improved and then used to predict LAC of OSR harvests, particularly HOLL ones, in different situations. Field experiments carried out at the experimental station in Changins (VD), Switzerland, in 2005–2006 showed that LAC was controlled by two additive quantitative genes. Consequently, an additive model was used for calculations with GeneSys. Results also showed that beyond a 20 m distance, a field of conventional OSR caused only a minor increase in LAC in a neighbouring HOLL OSR field, meaning that it is highly unlikely that pollen dispersal will compromise HOLL OSR quality under farmers’ conditions. These data were also used to evaluate the prediction quality of GeneSys. Briefly, the final LAC was slightly underestimated by the model, especially in the case of a high amount of conventional OSR volunteers leading to high LAC. Both experiments and simulations showed that the presence of volunteers of conventional OSR in the HOLL field had the most dramatic effect. In a short crop rotation, an important amount of volunteers significantly increased the LAC, but this can be controlled by adequate tillage and weed control in other crops of the rotation. Furthermore, in Switzerland, OSR is usually grown with an interval of at least 4 years in normal crop rotations, which is usually enough to prevent major contamination by volunteers if they are correctly managed.

Assays of the production of harmful substances by genetically modified oilseed rape (Brassica napus L.) plants in accordance with regulations for evaluating the impact on biodiversity in Japan

Environmental risk assessment of transgenic crops is implemented under the Cartagena Protocol domestic law in accordance with guidelines for implementing the assessment established by the Ministry of Agriculture, Forestry and Fisheries (MAFF) and the Ministry of Environment (MOE) in Japan. Environmental risk assessments of transgenic crops are implemented based on the concept of 'substantial equivalence' to conventional crops. A unique requirement in Japan to monitor the production of harmful substances, or allelochemicals, is unparalleled in other countries. The potential for allelochemicals to be secreted from the roots of transgenic crops to affect other plants or soil microflora or for substances in the plant body to affect other plants after dying out must be evaluated. We evaluated the allelopathic potential of seven transgenic oilseed rape (Brassica napus L.) lines that express glufosinate tolerance in terms of substantial equivalence to conventional oilseed rape lines, and established evaluation methods. Our results indicate no potential production of allelochemicals for any of the seven transgenic oilseed rape lines compared with conventional oilseed rape lines.

Forecasting the Adoption of Genetically Modified Oilseed Rape Prognosen hinsichtlich der Einführung von gentechnisch verändertem Raps Prévisions sur l’adoption de colza transgénique

SummaryForecasting the Adoption of Genetically Modified Oilseed RapeWe explore farmers’ willingness to adopt genetically modified oilseed rape prior to its commercial release and estimate the ‘demand’ for the new technology. The analysis is based upon experiments with arable farmers in Germany who were asked to choose among conventional and GM rapeseed varieties with different characteristics. Our analysis has shown that ex ante GM adoption decisions are driven by profit expectations and personal as well as farm characteristics. Monetary and technological determinants such as the gross margin advantage of GM oilseed rape varieties, expected liability from cross pollination and restricted flexibility in returning to conventional oilseed rape growing affect the willingness to adopt GM rape in the expected directions. The results further indicate that neighbourhood effects and public attitudes matter a lot, such that individual farmers may not feel entirely free in their technology choice. Our demand simulations suggest that monopolistic seed prices would be set at between €50 and €100 per hectare, leaving farmers with a small share of the GM rent. This raises the question as to whether the farmers surveyed would actually benefit from the approval of GM rape varieties if the technology were to be provided by a single firm.

Heterogeneity in the distribution of genetically modified and conventional oilseed rape within fields and seed lots

The implementation of co-existence in the commercialisation of GM crops requires GM and non-GM products to be segregated in production and supply. However, maintaining segregation in oilseed rape will be made difficult by the highly persistent nature of this species. An understanding of its population dynamics is needed to predict persistence and develop potential strategies for control, while to ensure segregation is being achieved, the production of GM oilseed rape must be accompanied by the monitoring of GM levels in crop or seed populations. Heterogeneity in the spatial distribution of oilseed rape has the potential to affect both control and monitoring and, although a universal phenomenon in arable weeds and harvested seed lots, spatial heterogeneity in oilseed rape populations remains to be demonstrated and quantified. Here we investigate the distribution of crop and volunteer populations in a commercial field before and during the cultivation of the first conventional oilseed rape (winter) crop since the cultivation of a GM glufosinate-tolerant oilseed rape crop (spring) three years previously. GM presence was detected by ELISA for the PAT protein in each of three morphologically distinguishable phenotypes: autumn germinating crop-type plants (3% GM), autumn-germinating 'regrowths' (72% GM) and spring germinating 'small-type' plants (17% GM). Statistical models (Poisson log-normal and binomial logit-normal) were used to describe the spatial distribution of these populations at multiple spatial scales in the field and of GM presence in the harvested seed lot. Heterogeneity was a consistent feature in the distribution of GM and conventional oilseed rape. Large trends across the field (50 x 400 m) and seed lot (4 x 1.5 x 1.5 m) were observed in addition to small-scale heterogeneity, less than 20 m in the field and 20 cm in the seed lot. The heterogeneity was greater for the 'regrowth' and 'small' phenotypes, which were likely to be volunteers and included most of the GM plants detected, than for the largely non-GM 'crop' phenotype. The implications of the volunteer heterogeneity for field management and GM-sampling are discussed.

Forecasting the Adoption of GM Oilseed Rape: Evidence from a Discrete Choice Experiment in Germany

AbstractThis paper explores farmers’ willingness to adopt genetically modified (GM) oilseed rape prior to its commercial release and estimates the ‘demand’ for the new technology. The analysis is based upon choice experiments with 202 German arable farmers. A multinomial probit estimation reveals that GM attributes such as gross margin, expected liability from cross pollination, or flexibility in returning to conventional oilseed rape significantly affect the likelihood of adoption. Neighbouring farmers’ attitudes towards GM cropping and a number of farmer and farm characteristics were also found to be significant determinants of prospective adoption. Demand simulations suggest that adoption rates are very sensitive to the profit difference between GM and non‐GM rape varieties. A monopolistic seed price would substantially reduce demand for the new technology. A monopolistic seed supplier would reap between 45% and 80% of the GM rent, and the deadweight loss of the monopoly would range between 15% and 30% of that rent. The remaining rent for farmers may be too small to outweigh possible producer price discounts resulting from the costs of segregating GM and non‐GM oilseed rape along the supply chain.

The influence of different nutrient levels on insect‐induced plant volatiles in Bt and conventional oilseed rape plants

Transgenic Bt (expressing the cry1Ac endotoxin gene) and conventional oilseed rape plants grown in different soils were used to study nutrient uptake and emission of volatiles after herbivore damage. All plants were greenhouse-grown in soils representing low-, medium- and high-nutrient levels. The concentrations of N, P, K, Mg and Zn were significantly affected by the transgene, while the main effect of soil type appeared in N, P, Ca, Mg, B, Mn and Zn concentrations in the plants. Plants with four to five leaves were infested with the third instar larvae of Bt-susceptible Plutella xylostella for 48 h, and samples of volatiles were collected and analysed. In the first experiment, the soil nutrient level had a significant effect on the emissions of (Z)-3-hexen-1-ol, (Z)-3-hexenyl acetate, hexyl acetate, (E)-4,8-dimethyl-1,3,7-non-atriene (DMNT), beta-elemene, gamma-bisabolene, alpha-bisabolene and (E)-nerolidol. The induction of these volatiles was significantly higher in infested conventional plants grown at a high-soil nutrient level compared to infested conventional plants at a low-soil nutrient level. In the second experiment, the soil nutrient level had a significant effect on the emissions of (Z)-3-hexen-1-ol, (Z)-3-hexenyl acetate and beta-elemene and, again, this was significantly higher in infested conventional plants grown at high-soil nutrient levels in comparison with infested plants at a low-soil nutrient level. In both experiments, the transgene effect was significant on the emissions of DMNT and (E,E)-alpha-farnesene. The differences in emissions between the two separate experiments suggest that growth conditions (particularly daylength) and sampling procedure may affect the ratio of compounds detected in the emission blend, even though the response to herbivory, nutrient availability and the transgene were similar.

Prediction of the combined effect of various GM contamination sources of seed: A case study of oilseed rape under Danish conditions

The potential GM contamination at each step in seed production can be predicted for conditions that correspond to a worst-case scenario. When the combined effect of the various GM contamination stages is calculated, the worst-case predictions of the different stages are normally added. This additive procedure to estimate the combined effect of GM contamination may be relevant to estimate the combined effect where a single farm is concerned, but may result in estimation errors when harvested seeds from a large number of farms are mixed. In this study, the consequences of treating the different stages of GM contamination as independent stochastic effects on the combined GM contamination have been estimated. A case study of GM contamination in organic and conventional oilseed rape crops under Danish conditions indicated that the greater part of GM contamination occurred at farm level and much less during transport and storage. Generally, it may be concluded that it is important to consider this uncertainty in the estimates of adventitious presence at each seed production step and also whether the different steps are independent.

Occurrence of genetically modified oilseed rape seeds in the harvest of subsequent conventional oilseed rape over time

Is returning to a conventional crop possible after growing a genetically modified (GM) variety? Oilseed rape volunteers in oilseed rape crops can cause seed admixture in the harvest. Farmers who desire to go back to conventional varieties after growing genetically modified varieties must comply with the 0.9% threshold of GM material in the harvest if they are to declare it as non-GM for food and feed use in Europe. The farm-scale GM platforms set up in France in 1995 were used to estimate the amount of GM seeds in the harvest of a conventional variety grown 3–8 years later in the same field. We show that over time the rate of GM seeds admixture in the harvest largely exceeded the European threshold in 6 out of 18 cases. In one case, the GM level was as high as 18%. However, it varied considerably according to the varieties used. These findings are discussed in the light of studies about seed shedding, seed dormancy and survival in the soil which are suggested to be the main source of large differences among GM varieties, which ultimately determines the frequency of volunteer plants growing amongst and harvested in admixture with the sown crop. These findings are equally discussed in light of differences of growth habit and potential competitiveness between conventional varieties responsible for different seed output by volunteers. To help cope with coexistence over time, we discuss appropriate uses of varieties and crop management in order to prevent seed admixture.

Predicting longer‐term changes in weed populations under GMHT crop management

SummaryThe UK Farm Scale Evaluations (FSE) compared the effects on biodiversity of management of genetically modified herbicide‐tolerant (GMHT) crops and conventional crops over the shorter term. We simulated population changes over seven 4‐year rotations (28 years) for weeds in crop rotations that included cereals and spring‐sown GMHT and conventional oilseed rape and beet, using FSE data and assuming the continuation of the weed management systems practised in the FSE. The weed density dependence that was modelled integrated change caused by population dynamics and farmers’ responses to changes in weed density. Predicted weed seed populations decreased under conventional management and at a greater rate under GMHT. Total seed densities were lower for GMHT cropping by a factor of 0.7–0.8. The predicted distributions of weeds had more fields with lower weed densities under GMHT cropping. Such changes could affect animal populations on farmland, depending on the scale of uptake of GMHT crop cultivars.