GM Varieties Research Articles

Discrimination of maize transgenic and non-transgenic varieties by laser induced spectroscopy (LIBS) and machine learning algorithms

BackgroundIn the last decades, the production and consumption of genetically modified agricultural products have increased markedly due to the worldwide population growth and rising demand for food and feed. Consequently, genetically modified crops have been extensively produced and consumed, which required identifying and discriminating transgenic and non-transgenic products. ResultsLaser-induced breakdown spectroscopy (LIBS) combined with chemometric methods was applied to identify and discriminate two varieties of conventional (not-genetically modified, NGM) maize from four varieties of transgenic maize (genetically modified, GM). The LIBS spectra acquired under reduced pressure (100 Torr) conditions over two ranges, i.e., 175–330 nm and 275–770 nm, were subjected to Standard Normal Variation (SNV) and multivariate methods such as Principal Component Analysis (PCA) to reduce data matrices dimensionality and spectral noise. The supervised machine learning algorithms k-nearest neighbor (k-NN) and support vector machine (SVM) have been applied to discriminate among NGM and GM maize reserving 25 % of data for external validation. The training data were employed for hyperparameter optimization of classifiers using the Leave-One-Out Cross-Validation (LOOCV) method. Considering all six maize varieties simultaneously, the highest training accuracy achieved was 90.56 %, with an external validation accuracy of 88.33 %. In an alternative approach based on pairwise combinations of one GM variety against one NGM variety, the best outcome achieved was 100 % LOOCV and external validation accuracy. ConclusionsThese results showed that LIBS supported by appropriate chemometric methods represents an alternative screening technique for identifying and discriminating transgenic from non-transgenic maize.

Derived categories of hearts on Kuznetsov components

AbstractWe prove a general criterion that guarantees that an admissible subcategory of the derived category of an abelian category is equivalent to the bounded derived category of the heart of a bounded t‐structure. As a consequence, we show that has a strongly unique dg enhancement, applying the recent results of Canonaco, Neeman, and Stellari. We apply this criterion to the Kuznetsov component when is a cubic fourfold, a GM variety, or a quartic double solid. In particular, we obtain that these Kuznetsov components have strongly unique dg enhancement and that exact equivalences of the form are of Fourier–Mukai type when , belong to these classes of varieties, as predicted by a conjecture of Kuznetsov.

Wishful Thinking vs. Hopeful Action: Response to Diehm on American Chestnut Restoration

ABSTRACT Christian Diehm has argued against using a genetically modified American chestnut variety in forest restoration. He is concerned that a GM variety sets a bad precedent and is disrespectful toward nature. He is also concerned that not enough has been done to consult with Native American tribes. We give evidence that consultation with tribes, environmental organizations, and the public is valuable and necessary – and that there is support for the GM chestnut. Genetic modification that saves a species from functional extinction shows respect to that species and its ecological relationships. Hopeful, wise, coordinated action is needed to save ecosystems.

Exploring the Inhibitory Effect of RASFF on China-EU Trade of Rice-Based Products

ABSTRACT Rice-based products exported from China to Europe have repeatedly encountered technical trade barriers. Using panel data from 24 states of the European Union during 2001–2017, this study builds a theoretical model to investigate the impact of implementation, intensity and structure of the Rapid Alert System for Food and Feed (RASFF) on China-EU rice-based product trade. The study found that RASFF has a serious inhibitory effect on the trade of traditional rice-based products because of detecting GM ingredients, showing an obvious lag effect, diffusion effect and structure effect. The negative effect occurs in entry process, and the inhibitory effect of border rejection and information notifications results in time lag, but the marginal effect of alerts for market links is insignificant. Moreover, the positive information disclosure effect of technical barriers implemented by individual members is much smaller than the negative diffusion effect. Finally, countermeasures and suggestions are proposed, including the source supervision of the test, the supervision of GM variety approval and GM seed production, the establishment of an early-warning and rapid-response mechanism to technical barriers of agricultural products, and food enterprise information.

Untargeted Proteomics-Based Approach to Investigate Unintended Changes in Genetically Modified Maize for Environmental Risk Assessment Purpose.

Profiling technologies, such as proteomics, allow the simultaneous measurement and comparison of thousands of plant components without prior knowledge of their identity. The combination of these non-targeted methods facilitates a more comprehensive approach than targeted methods and thus provides additional opportunities to identify genotypic changes resulting from genetic modification, including new allergens or toxins. The purpose of this study was to investigate unintended changes in GM Bt maize grown in South Africa. In the present study, we used bi-dimensional gel electrophoresis based on fluorescence staining, coupled with mass spectrometry in order to compare the proteome of the field-grown transgenic hybrid (MON810) and its near-isogenic counterpart. Proteomic data showed that energy metabolism and redox homeostasis were unequally modulated in GM Bt and non-GM maize variety samples. In addition, a potential allergenic protein—pathogenesis related protein −1 has been identified in our sample set. Our data shows that the GM variety is not substantially equivalent to its non-transgenic near-isogenic variety and further studies should be conducted in order to address the biological relevance and the potential risks of such changes. These finding highlight the suitability of unbiased profiling approaches to complement current GMO risk assessment practices worldwide.

Regulation of the GM crops circulation in Ukraine: problems and ways to solve them

The purpose of the article is to investigate the world experience of GMO management, highlight gaps in the regulation of GM crops in Ukraine and develop recommendations for their elimination, taking into account the best European practices and domestic characteristics. Research methods. In the research process the following methods were used: dialectical methods of cognition of processes and phenomena, monographic method (for analyze the spread of GM crops in the world), statistical (for analyze the dynamics of areas under GM crops in the world), empirical method (for comprehensive assessment of the current state of the use of GMO), abstract and logical methods (for theoretical generalizations and formulation of conclusions). Research results. In the article the world experience of GMO management was presented. The current state of regulation of the use of GM crops in Ukraine was described and the main directions of its improvement were outlined. Given the lack of registration of GM varieties of agricultural crops in Ukraine, the feasibility of forming an effective system of their registration and implementation of a system of control and monitoring of the cultivation of only registered varieties of agricultural crops was justified. This approach should protect against the spontaneous importation and illegal cultivation of GM crops. In addition, the necessity of introduction of the complex approach to regulation of use of GM crops and GM products in Ukraine and intensification of process of unification of the domestic and European regulatory framework in the field of regulation of the use of GMOs was substantiated. Scientific novelty. The current state of regulation of the use of GM crops and GM products in Ukraine was investigated and prospects for its improvement taking into account the best European practice were outlined. Practical significance. It has been established that there are gaps in the state control over the use of GMOs, as well as in the issues of liability for offenses in the field of GMO management and biosafety. Measures to eliminate them were proposed. Refs.: 12.

ОЦЕНКА РИСКОВ ПЕРЕОПЫЛЕНИЯ КУКУРУЗЫ ПРИ СОВМЕСТНОМ ВЫРАЩИВАНИИ НЕСКОЛЬКИХ ЛИНИЙ В УСЛОВИЯХ ЮГО-ВОСТОКА ЕВРОПЕЙСКОЙ ЧАСТИРОССИИ

The new Russian Federal law (No. 358 of 03.07.2016) prohibits the commercial use of GM plants in agriculture, but allows, since 2018, for the first time in Russia their cultivation and testing for research purposes. Consequently, there is a need to assess and develop criteria for safe co-cultivation of non-GM and GM varieties, which are currently absent in Russia. In this paper, it was established for the first time that the 10-15 m distance is sufficient to prevent cross-pollination between maize lines with an acceptable presence of 0.9 % of the donor’s genetic material, regardless of the recipient line, donor and recipient time flowering, and the wind direction in Saratov condition (South-West region of European part of Russia). The work aimed to assess the influence of the distance between pollen donor and recipient, wind direction, donor and recipient time flowering, and a buffer zone presence between them on the crossing frequency in mixed maize crops. The maize lines Korichnevyi marker (KM), GPL-1, Zarodyshevyi marker Saratovskii Purpurnyi (ZMS-P), Purpurnaya Saratovskaya (PS), as well as hybrids Purpurnyi (GP), Raduga and Tester 3 were grown (the experimental field of the Rossorgo, Saratov, South-West region of European Russia, 2018-2019). We planted the GP and ZMS-P lines as pollen donors in 2018 on a 3×80 m2 area with planting density of 7-10 plants per 1 m2. Between the pollen donor area, maize KM and GPL-1 lines were planted, and around them there were a 1290 m2 area of yellow-colored grain recipients (Raduga and Tester 3 hybrids). In September, 5-12 ears from each pollen recipient were harvested. The cross-pollination frequency was calculated as the ratio of purple grains (GP pollination result) or yellow grains with a purple spot (ZMS-P pollination result) to the total grain number in recipient lines. In 2018 it was established that the maximum percentage (from 0.1 to 13.2 %) derived from cross-pollination with two pollen donors depends on different factors. At closer distances (1-4 m), the cross-pollination increased 4-fold for the earlier flowering recipient. The percentage of crosses for recipient Raduga decreased 3 times with a 10 m increase in the distance and 11 times at a 40 m distance from the donor plants. Experiments in 2018 indicate that the 10 m distance from the pollen donor guarantees the percentage of crosses not exceeding the 0.9 % GM threshold in food products accepted in the European Union and Russia. In 2019, we used PS inbred line as a pollen donor. The PS was planted on a 3×5 m plot with Sudanese grass (Sorghum × drummondii) Allegory cultivar as a buffer zone 3 m wide to the East and West and 15 m long to the South-West and North-East. Yellow-grain hybrid Raduga was planted around the buffer zone. The frequency of crosses was calculated as the ratio of the number of purple grains to the total number of Raduga grains per ear. In 2018, the frequency of crosses was also estimated depending on the synchronism of flowering between pollen donors and recipients. The GPL-1 recipient with a 9-day difference from PG (pollen donor) in the beginning of flowering showed a 4 % lower pollination rate compared to a KM line with a flowering period closer to the PG pollen donor (1-day difference). Tall plants of PG donor of pollen prevented spreading pollen from a short ZMS-P donor to the Tester 3 and Raduga recipients in the direction of the wind rose. In 2019, no more than 0.9 % of purple grains were observed for the recipient Raduga when using a buffer zone of 15 m and more from the pollen donor in the wind rose direction. Based on the results of field experiments, the isolation distance from 15 m or more can be recommended to exclude cross-pollination of maize within the threshold of 0.9 % in the conditions of the South-East of the European part of Russia.

ASSESSMENT OF THE RISKS OF CROSS-POLLINATION DURING CO-CULTIVATION OF MAIZE LINES IN THE SOUTH-EAST EUROPEAN RUSSIA

The new Russian Federal law (No. 358 of 03.07.2016) prohibits the commercial use of GM plants in agriculture, but allows, since 2018, for the first time in Russia their cultivation and testing for research purposes. Consequently, there is a need to assess and develop criteria for safe co-cultivation of non-GM and GM varieties, which are currently absent in Russia. In this paper, it was established for the first time that the 10-15 m distance is sufficient to prevent cross-pollination between maize lines with an acceptable presence of 0.9 % of the donor’s genetic material, regardless of the recipient line, donor and recipient time flowering, and the wind direction in Saratov condition (South-West region of European part of Russia). The work aimed to assess the influence of the distance between pollen donor and recipient, wind direction, donor and recipient time flowering, and a buffer zone presence between them on the crossing frequency in mixed maize crops. The maize lines Korichnevyi marker (KM), GPL-1, Zarodyshevyi marker Saratovskii Purpurnyi (ZMS-P), Purpurnaya Saratovskaya (PS), as well as hybrids Purpurnyi (GP), Raduga and Tester 3 were grown (the experimental field of the Rossorgo, Saratov, South-West region of European Russia, 2018-2019). We planted the GP and ZMS-P lines as pollen donors in 2018 on a 3×80 m2 area with planting density of 7-10 plants per 1 m2. Between the pollen donor area, maize KM and GPL-1 lines were planted, and around them there were a 1290 m2 area of yellow-colored grain recipients (Raduga and Tester 3 hybrids). In September, 5-12 ears from each pollen recipient were harvested. The cross-pollination frequency was calculated as the ratio of purple grains (GP pollination result) or yellow grains with a purple spot (ZMS-P pollination result) to the total grain number in recipient lines. In 2018 it was established that the maximum percentage (from 0.1 to 13.2 %) derived from cross-pollination with two pollen donors depends on different factors. At closer distances (1-4 m), the cross-pollination increased 4-fold for the earlier flowering recipient. The percentage of crosses for recipient Raduga decreased 3 times with a 10 m increase in the distance and 11 times at a 40 m distance from the donor plants. Experiments in 2018 indicate that the 10 m distance from the pollen donor guarantees the percentage of crosses not exceeding the 0.9 % GM threshold in food products accepted in the European Union and Russia. In 2019, we used PS inbred line as a pollen donor. The PS was planted on a 3×5 m plot with Sudanese grass (Sorghum × drummondii) Allegory cultivar as a buffer zone 3 m wide to the East and West and 15 m long to the South-West and North-East. Yellow-grain hybrid Raduga was planted around the buffer zone. The frequency of crosses was calculated as the ratio of the number of purple grains to the total number of Raduga grains per ear. In 2018, the frequency of crosses was also estimated depending on the synchronism of flowering between pollen donors and recipients. The GPL-1 recipient with a 9-day difference from PG (pollen donor) in the beginning of flowering showed a 4 % lower pollination rate compared to a KM line with a flowering period closer to the PG pollen donor (1-day difference). Tall plants of PG donor of pollen prevented spreading pollen from a short ZMS-P donor to the Tester 3 and Raduga recipients in the direction of the wind rose. In 2019, no more than 0.9 % of purple grains were observed for the recipient Raduga when using a buffer zone of 15 m and more from the pollen donor in the wind rose direction. Based on the results of field experiments, the isolation distance from 15 m or more can be recommended to exclude cross-pollination of maize within the threshold of 0.9 % in the conditions of the South-East of the European part of Russia.

Evaluation of Pollen-Mediated Gene Flow from Purple-Colored Maize Line during Co-Cultivation with Yellow-Grain Maize Lines

In this paper, we consider the pollen-mediated gene flow of purple-colored maize lines during co-cultivation with yellow-grain pollen-recipient maize lines. We analyze the factors influencing pollen dispersion: wind (speed and direction), distance, the synchrony of the pollen donor and receptor flowering. It was established that the maximum percentage of crosses in maize lines with the same flowering dates was recorded at the distance of 1–4 m from the donor plant. The percentage of crosses decreased by a factor of 5 with an increase in the distance to 10 m. At a distance of 40 m from the donor plant, the percentage of hybrid grains among the freely pollinated grains of the recipient plant fell by a factor of 12.5. At close distances (1–4 m), hybrid grains on the cobs of the recipient lines were observed 4 times longer in the line with earlier flowering periods or in the line with the same flowering times, but with a sharper angle of leaves. According to our experimental data, at a distance of 10 m from the maize of a pollen donor, the guaranteed does not exceed the Russian threshold of 0.9% of the presence of GMO products in food (yield). The analysis of experiments on maize spreading with pollen in Volga region of Russia provides evidence-based recommendations for safe co-cultivation of non-GM and GM varieties and maize lines at the distance 10 m.

Growth, Protein Content, Yield and Yield Components of Malt Barley (<i>Hordeum vulgare</i> L.) Varieties in Response to Seeding Rate at Sinana District, Southeast Ethiopia

Identifying optimum seeding rate for crop varieties is an important agronomic practice to improve the productivity and the quality of the produces. Therefore, this study was conducted to evaluate the effect of seeding rate on the growth, protein content and yield performance of malt barley varieties grown under rain-fed conditions at Sinnana district, southeast Ethiopia. The treatments studied include five malt barley varieties (Singitan, Bahati, IBON174/3, HB - 1964 and Holker) and four seed rates (100, 125, 150, and 175 kg ha^-1). The experiments were arranged using factorial randomized complete block design with three replicates. The results revealed significant differences among the varieties and seeding rates for days to 50% heading, 90% physiological maturity, plant height, productive tiller (m²), 1000-kernel weight, grain protein content and grain yield (kg ha^-1). Among the barely varieties, Holker recorded the longest days to 50% heading (75.0 days) and plant height (91.79cm). The heavier 1000-kernel weight was produced from Singitan and Bahati (43.52gm) and (43.30gm) varieties, respectively. Increment in seed rate from 100–175 kg ha^-1 decreased days to 50% heading by 6% and thousand kernels weight by 23.51%. Furthermore, the interaction effect of variety and seeding rate showed significant differences on productive tiller, harvest index, grain protein content and grain yield. The use of 150 kg ha^-1 seed rate for variety Singitan resulted in higher number of productive tillers (1017.33 per m²), thousand kernels weight (43.52g), grain yield (3.63 t ha^-1), Hectoliter weight (62.98 kg ha^-1) and lower protein content (10.7%). As per the result of the partial budget analysis, higher benefit also recorded from the use of variety Singitan with a seed rate of 150 kg ha^-1. From the results of this study it can be concluded that, better crop performance, higher grain yield and economic return achieved from the combinations of variety Singitan, Bahati and HB-1964 with a seed rate of 150 kg ha^-1 and variety IBON174/3 and Holker with seed rate of 125 kg ha^-1.

Disharmonization in the Regulation of Transgenic Plants in Europe

Disharmonization in the Regulation of Transgenic Plants in Europe

Prospects of transgenic plants in the agro-sphere of Lviv region

The state and prospects of the use of transgenic plants in agriculture of Lviv region are considered in the paper. Transgenic plants are a kind of genetically modified organisms obtained by biotechnological methods using trans-transfer (between unrelated species) genes. In recent years, such cultures have become widespread in the world. The vast majority of soy, corn and other crops are planted with GM varieties. In the EU countries there is no broad perception of such cultures and there are significant restrictions on their distribution. Approximately 70 types of GMOs are allowed in the EU, including many decorative products (flowers) and about 58 GMOs for use in food and feed. In the world, 168 lines of genetically modified plants: corn, rape, cotton, potatoes, soya, rice, tomatoes, wheat and others were registered and allowed to be used for industrial production of food and feed. Our country also has some experience in obtaining transgenic organisms. According to unofficial data, in Ukraine transgenic 60–70% soybeans, 10–20% corn, 5% rape. In the near future, Ukraine should develop a clear concept of attitude towards GMOs, and the absence of a position on this issue complicates the planning of activities of the agro-sector. In the Lviv region there are prospects for growing GM varieties of soybean, corn and sunflower; there is evidence that a significant part of the crops of the first belongs to the modified varieties. Growing of GM sunflower in comparison with the usual one will have limited competitive advantages. Of the other crops that the area is specialized in, one can name potatoes whose GM varieties are used mainly for technical needs, and wheat, whose GM varieties have not yet been sufficiently tested. In the world market, there is a demand for genetically modified crops, an estimated 68% of Ukrainian agroholdings claim to be willing and able to grow GM crops for their legalization in Ukraine.

Unintended effects of transgenic rice revealed by transcriptome and metabolism

ABSTRACTGenetically modified (GM) organisms have been developed for decades. However, unintended effects are the main concerns of safety assessment that needs to be carefully investigated. Here, eight varieties of GM rice that were developed in China were selected to assess the unintended effects through transcriptome and metabolism. There are 2892–8758 differentially expressed genes (DEGs) and 7–50 metabolites at significant level between GM varieties and their isogenic counterparts, which were far fewer than that between traditional rice varieties. The function enrichment analysis showed altered transcription in stress-related pathway and starch and sucrose metabolism. DEGs shared among eight GM samples constitute less than 1% of the genes in the genome, and none of them is reported more than four times. The insertion effect on the nearby gene expression and the associated metabolism is only restricted to 50 genes. All the results provide a comprehensive analysis of unintended effects and indication of difference in Chinese transgenic rice based on their backgrounds, transformation, and insertion elements.

Systematic miRNome profiling reveals differential microRNAs in transgenic maize metabolism

BackgroundWhile some genetically modified organisms (GMOs) are created to produce new double-stranded RNA molecules (dsRNA), in others, such molecules may occur as an unintended effect of the genetic engineering process. Furthermore, GMOs might produce naturally occurring dsRNA molecules in higher or lower quantities than its non-transgenic counterpart. This study is the first to use high-throughput technology to characterize the miRNome of commercialized GM maize events and to investigate potential alterations in miRNA regulatory networks.ResultsThirteen different conserved miRNAs were found to be dys-regulated in GM samples. The insecticide Bt GM variety had the most distinct miRNome. These miRNAs target a range of endogenous transcripts, such as transcription factors and nucleic acid binding domains, which play key molecular functions in basic genetic regulation. In addition, we have identified 20 potential novel miRNAs with target transcripts involved in lipid metabolism in maize. isomiRs were also found in 96 conserved miRNAs sequences, as well as potential transgenic miRNA sequences, which both can be a source of potential off-target effects in the plant genome. We have also provided information on technical limitations and when to carry on additional in vivo experimental testing.ConclusionsThese findings do not reveal hazards per se but show that robust and reproducible miRNA profiling technique can strengthen the assessment of risk by detecting any new intended and unintended dsRNA molecules, regardless of the outcome, at any stage of GMO development.

Omics analyses of potato plant materials using an improved one-class classification tool to identify aberrant compositional profiles in risk assessment procedures

The objective of this study was to quantitatively assess potato omics profiles of new varieties for meaningful differences from analogous profiles of commercial varieties through the SIMCA one-class classification model. Analytical profiles of nine commercial potato varieties, eleven experimental potato varieties, one GM potato variety that had acquired Phytophtora resistance based on a single insert with potato-derived DNA sequences, and its non-GM commercial counterpart were generated. The ten conventional varieties were used to construct the one-class model. Omics profiles from experimental non-GM and GM varieties were assessed using the one-class SIMCA models. No potential unintended effects were identified in the case of the GM variety. The model showed that varieties that were genetically more distant from the commercial varieties were recognized as aberrant, highlighting its potential in determining whether additional evaluation is required for the risk assessment of materials produced from any breeding technique, including genetic modification.

A General Safety Assessment for Purified Food Ingredients Derived From Biotechnology Crops: Case Study of Brazilian Sugar and Beverages Produced From Insect-Protected Sugarcane.

Insect-protected sugarcane that expresses Cry1Ab has been developed in Brazil. Analysis of trade information has shown that effectively all the sugarcane-derived Brazilian exports are raw or refined sugar and ethanol. The fact that raw and refined sugar are highly purified food ingredients, with no detectable transgenic protein, provides an interesting case study of a generalized safety assessment approach. In this study, both the theoretical protein intakes and safety assessments of Cry1Ab, Cry1Ac, NPTII, and Bar proteins used in insect-protected biotechnology crops were examined. The potential consumption of these proteins was examined using local market research data of average added sugar intakes in eight diverse and representative Brazilian raw and refined sugar export markets (Brazil, Canada, China, Indonesia, India, Japan, Russia, and the USA). The average sugar intakes, which ranged from 5.1 g of added sugar/person/day (India) to 126 g sugar/p/day (USA) were used to calculated possible human exposure. The theoretical protein intake estimates were carried out in the “Worst-case” scenario, assumed that 1 μg of newly-expressed protein is detected/g of raw or refined sugar; and the “Reasonable-case” scenario assumed 1 ng protein/g sugar. The “Worst-case” scenario was based on results of detailed studies of sugarcane processing in Brazil that showed that refined sugar contains less than 1 μg of total plant protein /g refined sugar. The “Reasonable-case” scenario was based on assumption that the expression levels in stalk of newly-expressed proteins were less than 0.1% of total stalk protein. Using these calculated protein intake values from the consumption of sugar, along with the accepted NOAEL levels of the four representative proteins we concluded that safety margins for the “Worst-case” scenario ranged from 6.9 × 105 to 5.9 × 107 and for the “Reasonable-case” scenario ranged from 6.9 × 108 to 5.9 × 1010. These safety margins are very high due to the extremely low possible exposures and the high NOAELs for these non-toxic proteins. This generalized approach to the safety assessment of highly purified food ingredients like sugar illustrates that sugar processed from Brazilian GM varieties are safe for consumption in representative markets globally.

Occurrence of genetically modified rape in feedingstuffs

European Union law enforces labeling of products containing above 0.9% of GMO. The aim of this study was detection and quantification of genetically modified rape in feedingstuffs. Both the qualitative and quantitative analysis was based on Real Time PCR method. Amongst 432 examined samples of feed, 56 contained GM rape line GT73. Only in 8 of them did the content of GM rape exceed 0.9%. The source of GT73 rape contamination was rapeseed meal imported to Poland from the eastern countries, mainly Ukraine, which was confirmed in shipping documents attached to the samples. The efficient monitoring of GMO, especially for rape, is very important, because of the high possibility of contamination of traditional crops with GM varieties

Effect of Irrigation Regimes on Productivity and Water Utilization Efficiency of Three Oil Olive Varieties Under Drip Irrigation System.

A field experiment was conducted over a period of two successive growing seasons 2011and 2012 on 14 years old olive trees cultivated in sandy soil located at El-Bostan area in Ali Mubark experimental farm at south Tahrir region to investigate the effect of two different drip irrigation regimes (Traditional irrigation (TI) and deficit irrigation (DI)) on the productivity and water utilization efficiency of three oil olive cultivars (Olea europaea L.), Arbequina, Shamlali and Koroniki. The experimental design was split plot with three replicates (tree) where each tree has four emitters with discharge of 16 (TI) and 12 (DI) L/hr/emitter. Two applied irrigation water amounts (as mean value for two growing seasons) were used 28.61 and 21.46 m3/tree/year for TI and DI, respectively. The obtained data showed that fresh fruit weight, fruit and oil yield (as mean value for two growing seasons) were significantly decreased when olive trees subjected to deficit irrigation of the three olives varieties. With respect to olive varieties, the highest mean values of fruit weight were obtained from Arbequina variety (1.62 gm) followed by Koroniki (1.32 gm) while the lowest mean fruit weights were obtained with Shamlali (1.19 gm) variety. The percentage of reduction in fruit yield of trees under DI treatment (as mean value for two growing seasons ) were 15.3, 15.1 and 14.2 % as compared to TI regime for Shamlali, Arbequina and Koroniki olive varieties, respectively. The highest mean values of oil percentage (fresh weight basis) were obtained when olive trees subjected to deficit irrigation (DI) and Koroniki variety was the highest in oil percentage (19.52%). The highest values of water utilization efficiency (WUtE) were 2.73, 2.63 and 2.96 kg fresh weight fruit/m3 and were 0.50, 0.51 and 0.60 kg oil/m3 under deficit irrigation treatments (DI) (as a mean values of the two growing seasons) for Shamlali, Arbequina and Koroniki olive varieties, respectively.

Genetically modified crops a methodological proposal of indicators

The increase of cultivated areas with genetically modified crops (GM) poses a political challenge, both in terms of risk assessment as well as State regulation. To overcome this challenge, reliable, hierarchized and systematized information is required. Therefore, we present a methodology developed to select environmental impact indicators of these crops in four dimensions: ecosystemic, social, economic, and institutional. To obtain these indicators, two associated models were employed: Pressure–State–Response (OCDE, 2003) and Theme–Subthemes (Unite Nations, DESA, 2007). Then, the most significant components (or factors) were identified and valued in accordance with the background. In order to obtain the indicators, the variables to be measured were individualized within each component. Some indicators are directed to assess the pressures generated by the cultivation of transgenic crops on the ecosystem, and also its current status. The other indicators provide information about the State responses in terms of economic and regulatory actions. The proposed indicators have been adjusted for the Uruguay case, but the methodology has a global scope, although the reality of each country must be incorporated when applying them. Their purpose is to contribute to the cost-benefit analysis of public policies related to the agricultural sector based on new GM varieties. Currently, this methodology is being applied by the National Observatory of GM crops (under implementation) in Uruguay.

Comparison of drought stress response and gene expression between a GM maize variety and a near-isogenic non-GM variety.

Maize MON810, grown and commercialised worldwide, is the only cultivated GM event in the EU. Maize MON810, variety DKC6575, and the corresponding near-isogenic line Tietar were studied in different growth conditions, to compare their behaviour in response to drought. Main photosynthetic parameters were significantly affected by drought stress in both GM and non-GM varieties to a similar extent. Though DKC6575 (GM) had a greater sensitivity in the early phase of stress response as compared with Tietar (non-GM), after six days of stress they behaved similarly, and both varieties recovered from stress damage. Profiling gene expression in water deficit regimes and in a generalised drought stress condition showed an up-regulation of many stress-responsive genes, but a greater number of differentially expressed genes was observed in Tietar, with genes belonging to transcription factor families and genes encoding heat shock proteins, late embryogenesis abundant proteins and detoxification enzymes. Since induction of these genes have been indicated from the literature as typical of stress responses, their activation in Tietar rather than in DKC6575 may be reminiscent of a more efficient response to drought. DKC6575 was also analysed for the expression of the transgene CryIAb (encoding the delta-endotoxin insecticidal protein) in water deficit conditions. In all the experiments, the CryIAb transcript was not influenced by drought stress, but was expressed at a constant level. This suggests that though possessing a different pattern of sensitivity to stress, the GM variety maintains the same expression level for the transgene.