Showing papers on "Rapeseed published in 1999"

Allelochemicals released in soil following incorporation of rapeseed (Brassica napus) green manures.

Abstract: Plant-derived allelochemicals such as those produced by glucosinolate hydrolysis in Brassica napus, or rapeseed, are viable alternatives to synthetic compounds for the control of soil-borne plant pests. However, allelochemical production and residence times in field soils have not been determined. Soil samples were taken at 0-7.5 and 7.5-15 cm during a period of 3 weeks following plow-down of two winter rapeseed cultivars (Humus and Dwarf Essex). Soil samples were extracted with dichloromethane and analyzed using gas chromatography. Nine glucosinolate degradation products were identified-five isothiocyanates, three nitriles, and one oxazolidinethione. Maximum concentrations were observed 30 h after plow-down. Compounds derived from 2-phenylethyl glucosinolate, the principal glucosinolate in rapeseed roots, dominated the profile of degradation products. Shoot glucosinolates left few traces. This indicates that rapeseed roots may be a more important source of toxic fumigants than above-ground parts of the plant.

Estimation of seed weight, oil content and fatty acid composition in intact single seeds of rapeseed ( Brassica napus} L.) by near-infrared reflectance spectroscopy

Abstract: The potential of near-infrared reflectance spectroscopy (NIRS) for the simultaneous analysis of seed weight, total oil content and its fatty acid composition in intact single seeds of rapeseed was studied. A calibration set of 530 single seeds was analysed by both NIRS and gas-liquid chromatography (GLC) and calibration equations for the major fatty acids were developed. External validation with a set of 75 seeds demonstrated a close relationship between NIRS and GLC data for oleic (r = 0.92) and erucic acid (r = 0.94), but not for linoleic (r = 0.75) and linolenic acid (r = 0.73). Calibration equations for seed weight and oil content were developed from a calibration set of 125 seeds. A gravimetric determination was used as reference method for oil content. External validation revealed a coefficient of correlation between NIRS and reference methods of 0.92 for both traits. The performance of the calibration equations for oleic and erucic acid was further studied by analysing two segregating F2 seed populations not represented in the calibration set. The results demonstrated that a reliable selection for both fatty acids in segregating populations can be made by using NIRS. We concluded that a reliable estimation of seed weight, oil content, oleic acid and erucic acid content in intact, single seeds of rapeseed is possible by using NIRS technique.

Relationships Between Yield and Yield Components on Currently Improved Spring Rapeseed Cultivars

Abstract: This research was conducted in Erzurum in 1991 and 1992 seasons using 14 spring oilseed rape ( Brassica napus ssp. oleifera L.) cultivars in order to investigate the relationships between yield and yield components by correlation and path analyses. Positive values were obtained in both seasons between seed yield and the characters: days to flowering, plant height, number of branch, number of pods per plant, number of seeds per pod, pod diameter, pod length, 1000-seed weight, and oil content. However, seed yield was significantly and positive correlated with only number of pod per plant and 1000-seed weight in both seasons. Relationship between oil content and protein content was negative. Path analysis identified 1000-seed weight as having the greatest effect on seed yield, with number of pods per plant having a large secondary effect.

Determination of glucosinolates using their alkaline degradation and reaction with ferricyanide.

Abstract: Glucosinolates, a group of naturally occurring thioglucosides, are significant factors impairing the nutritional quality of rapeseed and postextraction rapeseed meal, restricting its use as high-quality protein animal feed. Currently, the European Community standards and Canola definition are being brought in line recommending cultivation and marketing of rapeseed with a glucosinolate content below 18 micromol of total glucosinolates per gram of seeds. Furthermore, some glucosinolates are of increasing interest in Brassica vegetables due to their proven cancer-preventing activities. A novel approach to the analysis of total glucosinolates is reported in this paper based on their alkaline degradation and subsequent reaction of released 1-thioglucose with ferricyanide. The reaction was followed spectrophotometrically using sinigrin and glucotropeaolin as model glucosinolates. The applicability of the method was demonstrated using rapeseed extracts after reducing the interfering effect of phenolics by their adsorption onto polyvinylpolypyrrolidone. Good agreement with official ISO methods was shown.

Detection of molecular markers associated with linolenic and erucic acid levels in spring rapeseed (Brassica napus L.)

Abstract: Summary Undesirable characteristic of rapeseed oil is a relatively high level of linolenic acid (18:3), which is easily oxidized leading to rancidity and a shortened shelf life of the oil. Previous attempts to reduce linolenic acid levels in rapeseed oil through breeding have been impaired by complex genetics and strong environmental sensitivity of this trait. Therefore, our objective was to develop molecular markers for low linolenic acid that could facilitate the breeding of low linolenic rapeseed. Bulked segregant analysis was employed to identify two RAPD markers associated with 18:3 in a doubled haploid population segregating for linolenic and erucic acid levels. Based on analysis of individual DH lines, the markers RM350 and RM574, representing two independent loci, accounted for a total of 39% of the genetic variability for 18:3 in this population. The marker RM350 alone accounted for 25% genetic variation for this trait with no evidence of recombination. Significant interlocus interaction found between the markers RM350 and RM574 suggested that epistasis was involved in the genetic control of 18:3 level in this population. Another marker designated as RM322, which was independent of the other two, was found significantly associated with the erucic acid level and oil content. RAPD markers identified in this study should be a useful tool for the early detection of low linolenic, or low or high erucic acid genotypes in rapeseed breeding programs based on doubled haploids.

Increasing Yield of Spring Oilseed Rape Hybrids through Introgression of Winter Germplasm

Abstract: Yields of spring oilseed rape (Brassica napus L.) hybrids are generally higher if derived from crosses of more distantly related spring cultivars. Winter cultivars are genetically very distinct from spring cultivars; however, it is not practical to use them directly as parents with spring cultivars for F 1 hybrids because of their noncoincident flowering times, and the excessively delayed maturity of the F 1 . Thus, we tested whether the introgression of winter germplasm into spring-type oilseed rape could further increase the yields of spring hybrids. Nineteen doubled-haploid lines, derived from a cross between a spring canola ('Stellar') and a winter rapeseed ('Major') cultivar, were selected based on early-flowering phenology and having a range of germplasm from Major estimated to be 21 to 74% by screening with 480 molecular marker loci. These lines were test-crossed to two spring cultivars and evaluated for yield in 1994, 1995, and 1996 in Madison or Arlington, WI. The mean yield of the experimental hybrids was higher than the yields of cultivars, inbreds, and spring by spring hybrids in every year. The oil content was similar in all categories of germplasm. A slight delay in maturity may have contributed to the yield advantage of the experimental hybrids; however, there was no significant correlation between flowering time and yield among these hybrids. This study indicates that winter rapeseed may be a valuable source of germplasm for spring hybrid breeding.

Physiological Investigation of the Impact of Nitrogen and Sulphur Application on Seed and Oil Yield of Rapeseed (Brassica campestris L.) and Mustard (Brassica juncea L. Czern. and Coss.) Genotypes

Abstract: Field experiments were conducted to determine the physiological basis of the effects of N and S interactions on seed and oil yield of Brassica species. Five combinations of N and S (in kg ha -1 ) 0S + 100N (T 1 ), 40S + 60N (T 2 ), 40S + 100N (T 3 ), 60S + 100N (T 4 ) and 60S + 150N (T 5 ), were used for this purpose. Nitrate reductase (NR) activity and ATP-sulphurylase activity in the leaves were measured at various growth stages, as the two enzymes catalyse rate-limiting steps of the assimilatory pathways of nitrate and sulphate, respectively. The activities of these enzymes were strongly correlated with seed and oil yield. The highest nitrate reductase activity, ATP-sulphurylase activity and yield were achieved with the combination T 3 in both species. Any variation from this combination decreased the activity of these enzymes, resulting in a reduction of the seed and oil yield of Brassica species. The higher seed and oil yield achieved in these species at T 3 could be due to optimization of leaf soluble protein and photosynthetic rate, as these parameters are influenced by N and S assimilation.

Evaluation of Salinity Tolerance of Canola Germination

Abstract: Canola (Brassica napus L., B. rapa L., Brassicaceae) is a genetically altered form of rapeseed with low erucic acid, a 22-carbon chain fatty acid that is used in a variety of polymer and lubricant products. Interest in canola is increasing steadily among health-conscious consumers due to its lowest content of saturated fatty acids (<70 g/kg) among major oil seeds. Domestic production of canola would reduce the import costs, enhance the productivity of American farms, and diversify agriculture (Starner et al. 1995). Canola oil is now the third largest source of edible oil following soybean and palm oil (Nowlin 1991). This increased demand, and the need for crop diversification, will undoubtedly promote increased acreage of canola in the western US, where some soils are prone to become saline (Francois 1994). Sims et al. (1993) reported that canola yields in Montana increased greatly with increased availability of water under normal conditions with lowered mean oil content. The average yield of 2.2 to 2.7 t/ha with oil content of 32% to 49% has been reported in Virginia during 1992 to 1995 (Virginia Agricultural Statistics 1995). The traditional approach to the cropping of arid lands has been to use conventional cultivars and modify the soil and water to meet the needs of the crop, or to make genetic selections from established cultivars for improved performance under arid conditions. Saline soils and saline irrigation waters present potential hazards to canola production. Germination is one of the most critical periods for a crop subjected to salinity. Germination failures on saline soils are often the results of high salt concentrations in the seed planting zone because of upward movement of soil solution and subsequent evaporation at the soil surface (Bernstein 1974). These salts interfere with seed germination and crop establishment (Fowler 1991). In an effort to develop the low erucic acid cultivars, the plant breeders are at the same time attempting to look for seedlings, which are tolerant to salinity. The two species of canola B. napus and B. campestris are classified as tolerant to salinity as per Maas and Hoffman (1977) salt tolerance classification table. Maas (1990) reported that even though both the species exhibit high salinity thresholds, the rate of yield decline above the thresholds was much greater than most other crops in the tolerant category. Shafii et al. (1992) reported that winter canola cultivars grown Pacific northwest had significantly higher oil content than the same ones grown in the Southeastern US. The tolerance of canola to salinity during germination however has not been reported. The objective of this study was to evaluate the germination response of canola to a wide range of cultivars, salinity levels, temperatures, and to determine their interactions.

Canola Oil Yield and Quality as Affected by Production Practices in Virginia

Abstract: Rapeseed (Brassica napus and B. rapa L., Brassicaceae), is now the third most important source of vegetable oil in the world. Canola (CANada Oil-Low Acid, an international registered trademark owned by the Canola Council of Canada) is the name given to a group of rapeseed cultivars that are low in erucic acid (22:1) and low in glucosinolates. Canola oil is considered healthy for human nutrition due to its lowest content of saturated fatty acids among vegetable oils and moderate content of poly-unsaturated fatty acids. The annual demand for canola oil by US consumers has increased from about 45 million kg to over 635 million kg, worth over $400 million (USCA 1997). The US production of canola increased from virtually zero in 1986 to over 150,000 ha in 1996 but at this level, meets less than 10% of domestic demand. The two Land Grant Universities in Virginia have attempted to develop canola as an alternate cash crop to substitute for winter wheat. Field research conducted from 1993‐1995 in Virginia indicated that canola could yield about 2000 kg/ha which compares well with yield from other US and foreign locations (Starner et al. 1996). The objective of the present studies was to characterize the effects of production practices (nitrogen fertilizer rates, planting dates, and seeding rates) on yield and quality of canola oil in Virginia. METHODOLOGY

Characterization of the Straw Stalk of the Rapeseed Plant as a Biomass Energy Source

Abstract: Oil seed plants are important biomass energy sources. The rapeseed plant, which yields a high amount of vegetable oil, has a major position among other oil seed plants. In this study the straw stalk of the rapeseed plant (type 00 Brassica napus L.) has been investigated as a candidate for a biomass energy source.

Oilseed cultivars developed from induced mutations and mutations affecting fatty acid composition

Abstract: One hundred and sixty-three cultivars of annual oilseed crops, developedusing induced mutations, have been officially approved and released forcultivation in 26 countries. The maximum number of cultivars have beenreleased in soybean (58), followed by groundnut (44), sesame (16), linseed(15), rapeseed (14), Indian mustard (8), castorbean (4), white mustard(3) and sunflower (1). The majority (118 of 163) of the cultivars havebeen developed as direct mutants and 45 of 163 by using the inducedmutants in a crossing programme. While in soybean 53 out of 58 cultivarswere selected as direct mutants, in groundnut 22 from 44 were developedafter hybridization. Eighty-three cultivars were developed directly byexposing seeds to gamma or X-rays. Attempts have been made to inferthe successful dose range, defined as the range which led to thedevelopment, registration and release of the maximum number of mutantcultivars for gamma and X-rays. The successful dose ranges in Gy forthe main oilseed crops are: soybean 100-200, groundnut 150-250, rapeseed600-800, Indian mustard 700 and sesame 100-200. The maincharacteristics of the new cultivars, besides higher yield, are altered planttype, early flowering and maturity and oil content. Mutants altering fattyacid composition have been isolated in soybean, rapeseed, sunflower,linseed and minor oil crops. New cultivars having altered fatty acidcomposition have been released in rapeseed, sunflower and linseed. Thelatter, previously grown for non-edible oil, has been converted to a newedible oil crop.

Very long chain and hydroxylated fatty acids in offspring of somatic hybrids between Brassica napus and Lesquerella fendleri

Abstract: Offspring of somatic hybrids between the zero-erucic acid rapeseed cv Hanna and Lesquerella fendleri were analysed regarding their fatty acid profiles. In the first back-cross generation one plant was found that produced a seed containing up to 16.5% erucic acid and 15% eicosaenoic acid (Line 1), as well as a seed having 4.3% ricinoleic acid (Line 2). This was interpreted as due to a contribution of elongase and hydroxylase genes from the L. fendleri genome since these two fatty acids are not produced in the recipient rapeseed cultivar Hanna. Crosses between Line 1 and cv Hanna resulted in the production of seeds with 35% erucic acid (F2). Furthermore, crosses between the F2 plants and the rapeseed cultivar Gulle, producing 35% erucic acid in the seeds, resulted in F3 seeds with 48% erucic acid. The highest amount of erucic acid, 61.5%, was found in the F6 generation after crossing Line 1 with a high erucic acid rapeseed line, HEAR, followed by self-fertilisation for two generations. When performing Southern-blot analysis on the F6 plants, seven of the nine analysed plants hybridised with the L. fendleri species-specific repetitive probe. The presence of the hydroxylase gene was also observed in the F6 generation of Line 1 according to Southern-blot analysis. Hybridisation with a hydroxylase probe was seen although no hydroxy fatty acids could be detected in any of the F6 plants. In parallel, Line 2 was crossed with HEAR cv Gulle and self fertilised. No hydroxy fatty acids were detected in the F2 generation of Line 2 and no specific hybridisation patterns could be found in the Southern-blot analysis.

The Development of Seed Quality in Brassicas

Abstract: ADDITIONAL INDEX WORDS. Brassica napus, rapeseed, Brassica oleracea, red cabbage, brussels sprouts, broccoli, hydrotime, controlled deterioration, seed aging SUMMARY. Brassica crops have indeterminate growth and flower over an extended period of time. Harvested seed is therefore comprised of seed of varying degrees of physiological maturity and quality. Using population-based threshold models, broccoli (Brassica oleracea L. Group Italica), brussels sprouts (B. oleracea L. Group Gemmifera), red cabbage (B. oleracea L. Group Capitata), and rapeseed (B. napus L.) were characterized during seed development with respect to sensitivity to abiotic stress (reduced water potential) and shelf life. Using these models our data suggests that the physiological patterns of seed development are the same in all brassica crops we have tested to date. These population-based models can be used to provide a biological basis in which to evaluate cultural, postharvest and storage practices to ensure the production and maintenance of seed vigor.

Predicting Decreases in Canola (Brassica napus and B. rapa) Oil and Meal Quality Caused by Contamination by Brassicaceae Weed Seeds

Abstract: Canola (edible rapeseed) crops are often infested by related weed species. This paper addresses effects that seeds from various Brassicaceae weeds may have on canola oil and meal quality. Seeds of common Brassicaceae weeds were collected from canola fields throughout northern Idaho. These were wild mustard, black mustard, birdsrape mustard, shepherd's-purse, flixweed, tum- ble mustard, and field pennycress. Collected seeds were physically described by weight, size, and shape and were analyzed for oil concentration, fatty acid composition, and glucosinolate concentra- tion. Seed weights ranged from 0.1 to 2 g/1l,000 seed. Oil concentration in the weed seeds ranged from 25 to 38%, with erucic acid levels ranging from less than 1 to 47%. Glucosinolate concentration in the mustard weed seeds was over 100 pLmol/g oil-free meal, except for shepherd's-purse, which had only 3.4 ,umol/g. Using these data, a simple model predicts that both canola oil and seed meal quality can be adversely affected by contamination with weed seeds. Increased erucic acid concen- tration in modeled admixtures was the most likely oil quality problem associated with weed seed contamination. Glucosinolate concentration in modeled admixtures was higher than acceptable only in those admixtures that also had erucic acid levels that exceeded canola quality standards. Canola- quality oil and seed meal can be maintained with conspicuous weed seed mixtures up to the 2% maximum allowed in U.S. No. 1 canola. However, canola-quality oil and seed meal was not achieved when a 5% weed seed mixture allowed in No. 2 canola was evaluated with the model. Nomenclature: Birdsrape mustard, B. rapa L. #a BRSRA; black mustard, B. nigra (L.) W.J.D. Koch # BRSNI; flixweed, Descurainia sophia (L.) Webb. ex Prantl # DESSO; field pennycress, Thlaspi arvense L. # THLAR; shepherd's-purse, Capsella bursa-pastoris (L.) Medic. # CAPBP; tumble mustard, Sysimbrium altissimum L. # SSYAL; wild mustard, Brassica kaber (DC.) L.C. Wheeler #

Manipulation of Plant Oil Composition for the Production of Valuable Chemicals

Abstract: The first transgenic crop with a modified seed oil composition was released for commercial use in 1995 Many additional transgenic rapeseed varieties expressing novel seed oils or proteins are now under development Recent research advances in Arabidopsis molecular genetics and the emerging relatedness between the Arabidopsis and Brassica genomes will enable more radical manipulation of many key agronomic traits in rapeseed These will range from greatly improved seed oil yield to the production of seed oils with defined fatty acid contents ranging from C8 to C24 chain lengths and including many desirable functionalities including double bonds, triple bonds, hydroxy and epoxide groups Much of the technology currently being development in rapeseed and soybean oil modification will be directly applicable to other oil crops including high yield tropical perennials such as oil palm

Absorption in rats of rapeseed, soybean, and sunflower oils before and following moderate heating

Abstract: Rapeseed, soybean, and sunflower oil were heated for 15 min in a 5-mm oil layer in a pan at 180°C. The fatty acid composition was almost unaffected by heating, while the polymer content rose slightly and the tocopherol content decreased, except in soybean oil. The absorption of oils before and after heating was investigated in lymph-cannulated rats. Oils were administered as emulsions through a gastrostomy tube and lymph was collected during the next 24 h. The highest accumulated lymphatic transport of total fatty acids was observed after administration of rapeseed oil, and the lowest after heated sunflower oil. The accumulated transport was similar for all unheated oils. The transport of fatty acids was significantly lower in rats receiving heated oil compared to those receiving the corresponding unheated oil. Small increases in polymers may have contributed to the decreased lymphatic transport of oil following heating, although this probably does not fully explain the effect. The absorption of sunflower oil was more affected by heating than the absorption of soybean or rapeseed oil. Furthermore, the largest decrease in total activity of tocopherols following heating was observed in sunflower oil. Overall, these results demonstrate that the absorption of vegetable oils is affected by moderate heating.

Lecithin-containing edible oil and its use

Abstract: PROBLEM TO BE SOLVED: To obtain the subject edible oil, in spite of a liquid oil, having improved fluidity and the same or higher improved stability to oxidation as that of palm oil and excellent flavor by making the edible oil have the whole fatty acid composition of colza oil containing oleic acid and linolenic acid in a specific ratio. SOLUTION: This edible oil contains a colza oil and a lecithin. The colza oil is a colza oil obtained from the seed of rapeseed belonging to the genus Canola and the whole fatty acid composition of colza oil comprises 70-85 wt.% of oleic acid and 0.5-5 wt.% of linolenic acid. In the edible oil, preferably the whole fatty acid composition further contains 1-5 wt.% of palmitic acid. Seed of rapeseed of Canola 46A40 can be used as the seed of rapeseed.

GENESYS : A model of the effects of cropping system on gene flow from transgenic rapeseed

Abstract: The aim of the model is to evaluate the influence of cropping systems on transgene escape from rapeseed crops to rapeseed volunteers in time and space. The model input variables are the regional field pattern, crop succession and cultivation techniques. The main output variables are, for each year and plot, the number of individuals per m 2 and the genotype proportions of the adult rapeseed plants, the newly produced seeds and the seedbank. The model comprises an annual life-cycle for volunteer and cropped rapeseed plants simulated for each plot and year; the relationships between the various life-stages depend on crop type and management. Pollen and grain exchanges between plots depend on distance between plots and cropping system. With the help of the simulations performed with the model, it is possible to identify low-gene-flow cropping systems or the minimum distance between rape plots to avoid contamination of the harvest product, to estimate the consequences if one farmer does not manage his rape volunteers correctly etc.

Efficacy of Seed Crop Meals for the Management of Columbia Root-Knot Nematode Meloidogyne chitwoodi on Tomato Under Greenhouse Conditions

Abstract: Efficacy of oilcakes from soybean, cotton, sesame and rapeseed on the Columbia root-knot nematode Meloidogyne chitwoodi on tomato (Lycopersicon esculentum) was investigated under green house conditions. All crop meal amendments significantly increased foliar fresh and dry weights, compared to the unamended control. Rapeseed meal or sesame meal at all application rates and soybean meal at 4.94 tons/ha application rate produced symptoms and incidence of phytotoxicity. Application of meals at all rates consistently reduced nematode populations compared to the unamended check (P = 0.05), with the exception of rapeseed meal at 1.24 tons/ha. Soybean meal at 1.24 or 2.47 tons/ha resulted in the highest amount of fresh foliage and the lowest numbers of M. chitwoodi in soil and in root tissue compared to unamended soil and soil amended with rapeseed, cotton, or sesame meals.

Spezifischer Nachweis von gentechnisch verändertem Raps in Honig

Abstract: Rapeseed is one of the most important oil producing plants in Germany, Asia and North America. Rapeseed oil is e.g used for the production of salad oil and edible fat. Microscopical analysis of rapeseed pollen is an important item for the determination of the authencity of honey. Although the analysis of rapeseed DNA would be therefore of great interest. Glufosinate resistant rapeseed is one of the prominent genetically modified plants for cultivation and commercialization in Europe. The same transgenic sequence is also present in genetically modified maize and sugar-beets. For surveillance the Novel Food legislation as well as the labelling of genetically modified seeds and feeds an appropriate method for the detection of transgenic DNA is necessary. This paper describes a method for the extraction of DNA from rapeseed pollen in honey and the specific detection of the new trait (Glufosinate resistance) in genetically modified rapeseed, maize and sugar-beets.

High Performance 4-Cycle Lubricants from Canola

Abstract: IDENTIFICATION OF A MARKET Developing a new market for an established international crop like canola (Brassica napus L., Brassica rapa L., Brassicaceae) requires significant care and study. Canola has been identified by several authors as a highly desirable food oil. Canola oils are relatively rich in monounsaturated fatty acids and with small percentages of both saturated and polyunsaturated fats. Canola can be differentiated from rapeseed by Canadian standards of low erucic acid and low glucosinalate content. Canola’s relatively high percentage of monounsaturated fats, natural antioxidants, and lubricity make it ideal for lubricant applications To develop a canola oil industry which does not compete with existing canola markets requires identification of new applications. Three objectives for a canola-based lubricant were identified: first, an oil functionality equal to or better than comparable petroleum oils; second, a cost which is acceptable to the general consumer; and third a product which is environmentally benign, allowing for some premium in cost and market. Currently, numerous vegetable oils are used in lubricant applications. Current lubricant applications include additives in synthetic oils, transmission fluids, two-cycle motor oils, chain oils, hydraulic oils, greases and biodiesels. US consumption of these oils requires about 8 million kilograms of vegetable oil annually. This represents about 9% of all industrial applications for vegetable oils (USDA-ERS, 1995). To identify a market not currently served by a vegetable oil, a product was selected which is not typically vegetable oil based: four-cycle motor oils. This market consumes 9.66 billion liters of refined petroleum oil annually within the United States for lubrication purposes. Approximately 3.9 billion liters are consumed solely for four cycle engine oil (Fig. 1).

Rapeseed oil : An autoxidative food lipid

Abstract: Rapeseed oil, a by-product of rape' belonging to the Brassica family, has been used as a cooking oil in Asia for many generations. However, its use in Europe and North America has been hampered by its toxicity. There are three health problems concerning rapeseed oil: myocardial lipidosis, myocardial necrosis, and impaired oxidative phosphorylation. The toxicity was thought to be attributed to the erucic acid content, which comprises 40-50% of the total fatty acids in the oil. This has led to the newly developed low erucic acid rapeseed (LEAR) oil (0.4 2.0%). Spanish toxic oil, which resulted in more than 800 deaths consisted, however, mostly of LEAR oils. Prediction of the safety of LEAR oils in man is thus questionable. The LEAR cultivars are high in glucosinolates. A second new type of rapeseed oil, low in both erucic acid and glucosinolates, called canola is now the major rape by-product. This review article discusses the potential factors, which could be potentially responsible for the toxicity of Spanish toxic oil.

Strategies for the Investigation of N-Efficiency in Oilseed Rape

Abstract: Breeding for increased nitrogen efficiency in winter rapeseed is gaining increased attention for several reasons. Ecologically, the possible leaching of nitrate from crop residues in autumn and winter into the groundwater represents a problem. Economically, N-fertilizer is applied in rapeseed in amounts up to 200 kg N/ha and breeding of cultivars that give high yields with a reduced amount of N fertilizer could help maintaining profit margins Politically, EC regulations concerning the subsidy of the rapeseed crop and environmental aspects of rapeseed cultivation may become more restrictive in the future.

Genetic modification of erucic acid biosynthesis in Brassica napus

Abstract: Erucic acid (C22:1), the major component of traditional rapeseed (Brassica napus L.) triacylglycerols (TAG), is detrimental to the food quality of the oil. Progress in rapeseed breeding has led to the development of double-low rapeseed (Canola) cultivars. Conversely, for industrial purpose the C22:1 content of rapeseed oil should be as high as possible. Molecular biologists have demonstrated that the development of high-erucic acid rapeseed (HEAR) genotypes containing considerable amounts of erucic acid in the sn-2 position of the TAG, is an elementary step in order to increase the C22:1 content of rapeseed oil. Furthermore, transgenic HEAR bearing trierucin in its seed oil needs improvement by stimulating the biosynthetic capacity for fatty acid elongation. With regard to the molecular basis of C22:1 inheritance it is supposed that true erucic acid alleles are expressing different isoforms of the elongase condensing enzyme (β-ketoacyl-CoA synthase). In this concern, further work aims in the identification, molecular characterization and accumulation of more effective alleles for C22:l synthesis in B. napus, involving transgenic HEAR lines with significant trierucin in their seed oil.