A time-course study of the effect of sulphur on glucosinolates in oilseed rape (Brassica napus) from the vegetative stage to maturity

Samples consisting of the whole above-ground part of the oilseed rape plant (Brassica napus L), were taken every 2 weeks from before stem extension to maturity. The plants were separated into vegetative tissue, floral tissue, pods and seeds (when these components appeared), and the individual glucosinolates present were quantified by high performance liquid chromatography. A high glucosinolate variety (Rafal) and a low glucosinolate variety (Cobra) were compared. The effect of sulphur (32 kg ha^?1 elemental sulphur applied at the beginning of stem extension) on the various parts of the plant was investigated. Total glucosinolate concentration in all plant parts was higher in Rafal than in Cobra. Glucosinolate concentration in the vegetation declined over time, most noticeably when the flowers and seeds were produced, and glucosinolate concentration of the pods also fell as that of the seeds rose. It is suggested that there may have been some redistribution of glucosinolates or glucosinolate precursors within the plant as maturity approached. Changes occurred in the proportions that individual glucosinolates contributed to the total glucosinolate content, and this may be relevant to plant/pathogen relationships. Sulphur application increased the glucosinolate concentration of the vegetative tissue by mid April and also increased the glucosinolate concentration of the flowers. It is suggested that this could affect the plant's resistance to disease.     

Immunological investigation of lipases in germinating oilseed rape,Brassica napus

An anti-lipase antibody has been used to investigate the lipases of cotyledons from germinating seedlings of oilseed rape, Brassica napusL, var Mikado. Immunological and enzymic assays revealed that lipases were confined to germinating seeds and were absent from other tissues, such as developing seeds, leaves, roots and flowers. The antibody totally inhibited microsomal lipase activity at a ratio of 12 μg IgG protein: 10 μg microsomal protein. It was shown by immunoblotting of microsomal, oil-body and total cotyledon proteins separated by gel electrophoresis that, in each case, the antibody specifically bound to a single polypeptide. This polypeptide had an electrophoretic mobility consistent with a molecular weight of 56 kDa. The appearance and subsequent decline of the 56 kDa polypeptide during the first 10 days of germination closely followed that of the lipase activity, both in microsomal protein and total cotyledon protein fractions. An ELISA for the lipase demonstrated that the amount of immunoreactive microsomal lipase present at each stage of germination was proportional to its enzymic activity. The enzymic and immunological activities of the microsomal lipase each exhibited buoyant densities of 1.087 g ml^?1 on sucrose density gradients. Lipases were present in only very small amounts in dry seeds and were synthesised de novo after 2–3 days of germination.     

Changes in forage and oilseed rape (Brassica napus) root glucosinolates in response to attack by turnip root fly (Delia floralis)

Three genotypes of forage rape and two of winter oilseed rape (Brassica napus L), grown in a glasshouse, were inoculated with Delia floralis Fall eggs at 5 weeks and their roots were sampled after a further 6 weeks of larval attack. Individual and total glucosinolates were examined in seed and roots using HPLC. No clear relationship was found between seed and root total or individual glucosinolate content. Major differences in glucosinolate composition were found between uninoculated control roots. In two doublezero oilseed rapes, phenylethyl glucosinolate was predominant whereas, in the three forage rapes, 2-hydroxy-but-3-enyl was the major glucosinolate. Attack by D floralis larvae considerably modified both concentrations and relative proportions of individual glucosinolates in roots. The total glucosinolate content decreased for all of the rapes except double-zero oilseed rape WRG35. In all rapes the proportion of aromatic to aliphatic glucosinolates increased after attack, largely due to increased levels of indolebased glucosinolates; 1-methyoxy-3-indole methyl glucosinolate increased by over 88%. The total aliphatic glucosinolate content of all rape roots with the exception of WRG35 was reduced by 39–56% after attack. Possible causes for altered glucosinolate metabolism are discussed in relation to observed differences in levels of susceptibility to turnip root fly attack.     

The response of double-low winter oilseed rape to fertiliser sulphur

The effect of soil-applied ammonium sulphate (10, 20, 30, 50 and 80 kg S ha^?1) and agricultural gypsum (20 and 50 kg S ha^?1) and of foliar-applied elemental sulphur (20 kg S ha^?1) on the seed yield and chemical composition of double-low cultivars of winter oilseed rape was determined at 11 sites in England during 1989-1991. Significant (P ? 0.05) mean seed yield responses to applied sulphur (S) of 10 and 17% were obtained at two sites on sandy soils in northern England which showed symptoms of severe S deficiency. At a third site on a shallow calcareous soil in south-west England, which did not show S deficiency symptoms, seed yield was consistently but not significantly increased by an average of 8%. At one of the sites in 1989, application of ammonium sulphate caused leaf scorch and, at the maximum rate of S applied, seed and oil yield were decreased. No conclusions were reached regarding the amount of S required for maximum yield response. The S treatments decreased seed oil content by an average maximum of 9 mg g^?1. Seed glucosinolate content was increased by a greater amount at the two sites in northern England compared to other sites, where increases averaged only 3 μmol g^?1. Analysis of individual glucosinolates in the harvested seed from one of the sites in northern England showed that only the alkenyl glucosinolates were increased by S application. Yield responses were best predicted by total S concentrations and N : S ratio values in young fully-expanded leaves at flowering. Foliar-applied elemental S was consistently less effective in raising leaf S content than ammonium sulphate. Gypsum was occasionally found to be less effective than ammonium sulphate as an S fertiliser.     

The effect of cultivar,sample date and grazing on the concentration of s-methylcysteine sulphoxide in oilseed and forage rapes (brassica napus)

A study of the S-methylcysteine sulphoxide (SMCO) concentration in foliage from four double-zero, three single-zero cultivars of oilseed rape and four cultivars of forage rape revealed little inter-cultivar variation. Significant differences were however found with respect to harvest date, with the concentration of SMCO remaining fairly constant over the early winter period but then increasing as the plants commenced regrowth in the late winter-early spring. Continual exposure of plots to grazing wild rabbits produced small but statistically significant changes in SMCO concentration but compared with seasonal differences the changes due to grazing were small and inconsistant. These findings are discussed in relation to the recently reported harmful effects of double zero oilseed rape cultivars on browsing wildlife.     

A time-course study of glucosinolates in the ontogeny of forage rape (Brassica napus L)

One cultivar and two breeding lines of forage rape, grown in a glasshouse, were sampled at weekly intervals from 9 to 22 weeks after sowing. Separate determinations of glucosinolate content were made on leaves and stems by HPLC. There were differences in the proportion and concentration of individual glucosinolates between the rapes and between leaves and stems, showing that levels of individual glucosinolates cannot be predicted from total glucosinolate content. Of particular interest was the variation with harvest date in the levels of individual glucosinolates. This has considerable implications for the comparison of levels of individual glucosinolates between cultivars and crops, and suggests that detailed agronomic field studies are required to determine whether the intake by animals of potentially toxic glucosinolates, in particular progoitrin, can be minimised by exploiting these seasonal differences in glucosinolate concentrations. Progress has been made in lowering the level of this glucosinolate, and the possibility of breeding forage rape with very low or zero levels of progoitrin is indicated.     

Determination of total glucosinolates in oilseed rape by X-ray spectrometric analysis for oxidised sulphur (S6+)

A rapid X-ray spectrometric (XRS) method has been developed for the determination of the total glucosinolate content of oilseed rape and other Brassica oilseeds. The method is based on analysis for fully oxidised sulphur (S⁶⁺), which includes half the sulphur (S) in the glucosinolate molecule, and the S in sulphate. Results are highly correlated with glucosinolate content determined by glucose release, a standard method widely used in Australia. The relationship is total glucosinolates = (23·97 S⁶⁺ -9·43) r² = 0·987, where the glucosinolate content is expressed as μmol g^?1 and the S⁶⁺ content in mg g^?1. The relationship is applicable to seed of any glucosinolate content and to meal, and is unaffected by changes in protein sulphur content. The correlation of glucosinolates with S⁶⁺ is shown to be closer than the correlation with total S. The latter correlation forms the basis of the existing XRS method, used within the European Community in recent years. The advantages of S⁶⁺ derive from the linearity of the regression and the elimination of errors caused by variation in protein content. The method should be valuable to the Australian oilseed industry because it allows the rapid screening of breeding lines to ensure low glucosinolate content and the assessment of deliveries for crushing and of meal.     

Composition and potential uses of mesquite pods (Prosopis pallida L): Comparison with carob pods (Ceratonia siliqua L)

The composition of mesquite pods (Prosopis pallida L) (PP), a legume cultivated in the large desert areas of Peru, was studied. These fruits have at the present time very little practical or commercial use. Taking into account the morphological and compositional similarities to Mediterranean carob pods (Ceratonia siliqua L) (CS), which are widely used in the food industry, some applications of PP are considered. PP shows better nutritional properties than CS, mainly owing to its lower polyphenolic content and higher protein digestibility.     

甘蓝型油菜表皮特异硫蛋白(ESP)的序列分析及其诱导表达

为了揭示植物激素及环境胁迫对甘蓝型油菜(Brassica napus)表皮特异硫蛋白(ESP)表达的影响,以中双9号品种为材料,采用同源克隆法获得一编码甘蓝型油菜表皮特异硫蛋白(BnESP)的cDNA,序列分析表明其编码蛋白BnESP含有343个氨基酸,与青花菜(Brassica napus)ESP有99%的相似性,与拟南芥腈特异性蛋白、类黑芥子酶结合蛋白、茉莉酸诱导蛋白有较高的同源性。荧光定量RT-PCR分析显示,甲基茉莉酸和机械伤害快速激活BnESP的表达,苯丙噻重氮和核盘菌(Sclerotinia sclerotiorum)抑制其表达。研究证明BnESP是茉莉酸诱导蛋白,可能在水杨酸和茉莉酸信号的互作及油菜对S. sclerotiorum的反应网络中起作用。     

Variation in S-methyl cysteine sulphoxide concentration with harvest date in forage rape (Brassica napus)

Patterns of variation in glucosinolate concentrations of three forage rapes (Brassica napus L) over a 14-week period suggest that a high frequency of sampling the crop is necessary to determine when animals are likely to have a minimum intake of such anti-metabolites (Macfarlane Smith and Griffiths 1988). A study of S-methyl cysteine sulphoxide (SMCO), which causes anemia in animals (Greenhalgh 1969), in the same three rapes showed similar variation in concentration with time in both the leaf and stem. However, for any given sampling date, SMCO concentrations were very similar throughout the plant. Variation in nitrogen concentration within the plant did not follow the same pattern as SMCO.     

Effect of harvest date and pod position on glucosinolates in oilseed rape (Brassica napus)

Pod samples from four varieties of winter oilseed rape (Brassica napus L) were taken twice weekly from 26 to 3 days before harvest from upper, middle and lower third portions of the main raceme. Seeds were analysed for individual glucosinolate concentration by HPLC. Total glucosinolate content increased suddenly during the sampling period. The timing of the increase depended on variety but occurred before harvest would have been practical. Proportions of individual glucosinolates in Rafal, the only “high” glucosinolate variety examined, did not change over the sampling period. In the other varieties, the proportion of 2-hydroxy-but-3-enyl (progoitrin) increased and the proportion of 2-hydroxy-pent-4-enyl decreased as sampling progressed, so that the concentration of individual glucosinolates could not be predicted from total glucosinolate content. The ‘low’ glucosinolate varieties contained a significantly smaller concentration of progoitrin and summed aromatic glucosinolates than Rafal. Variations in glucosinolate content with pod position were smaller than those due to sampling date, but there was a greater concentration of glucosinolates in seeds from pods lower on the terminal raceme. The results would indicate that care should be taken if seed samples from the plant are taken.     

我国油菜生产布局时空演变及影响因素分析

为进一步优化我国油菜生产布局,基于生产集中度指数、生产规模指数、空间重心分析、产地集中度系数等数据模型对21世纪以来我国油菜生产布局时空演变及影响因素进行分析。结果表明：进入21世纪以来,我国油菜主产省基本无变化,但受各省不同产业定位的影响,四川、湖南、重庆、云南油菜生产集中度指数逐年上升,安徽、江苏、浙江逐年下降;油菜产业扶持政策的陆续实施推动南方地区油菜生产规模自2007年逐渐上升,北方对应下降,东、中、西三部及七大产区不同的区位特性导致国内油菜生产在空间布局上总体呈现“东减、中稳、西移”的特征;油菜籽产量及油菜播种面积空间重心则由中部逐渐向西南迁移;油菜产地集中度系数总体呈波动上升的趋势,即油菜生产趋向于主产地。受自然环境、产业模式、政策扶持、科技创新等综合影响,我国油菜产业的区位优势更加明显,空间布局日益优化。建议通过长江流域油菜优势产业带建设、油脂加工企业政策扶持、北方盐碱地开发、南方冬闲田扩种及油菜多功能开发利用等措施进一步提升我国油菜产业国际竞争力。     

A comparison of rapid- (X-ray fluorescence,near-infrared reflectance) and glucose-release methods for the determination of the glucosinolate content of oilseed rape (Brassica oleracea)

Rapeseed (Brassica oleracea L) samples representing the wide range of glucosinolate contents typical of both ‘single-low’ and ‘double-low’ varieties grown in the UK were analysed by X-ray fluorescence and by near-infrared reflectance spectroscopy, currently considered to be alternatives for the rapid analysis of glucosinolates in rapeseed. Each physico-chemical technique was compared with an established method based on the enzymic release of glucose. The results of such intercomparisons are reported and the relative advantages and disadvantages of the methods are discussed.     

Influence of nitrogen and sulphur on the glucosinolate profile of rapeseed (brassica napus l)

Clear influence of N and S applications on the profile of individual glucosinolates in the seeds of winter oilseed rape (Brassica napus L) was found in field experiments. The major effect of N was on the relative abundance of the four alkenyl glucosinolates. Increasing the N rate increased the relative proportion of 2-hydroxybut-3-enyl at the expense of pent-4-enyl, and to a lesser extent, 2-hydroxypent-4-enyl, in the double-low (low erucic acid and low glucosinolates) variety Cobra, but at the expense of but-3-enyl in the single-low (low erucic acid) variety Bienvenu. The results strongly suggest that a high N supply favours the hydroxylation step from but-3-enyl to 2-hydroxybut-3-enyl. In contrast, the major effect of S appeared to be on the relative abundance of the alkenyl and indole groups as a whole. Sulphur deficiency decreased the concentrations of the alkenyl glucosinolates more than those of the indole glucosinolates, whereas S application to a S-deficient crop resulted in a larger response in the alkenyl group than in the indole group. The more sensitive response of alkenyl glucosinolates to the plant S status is probably due to the requirement of methionine in their biosynthesis, as compared with the indole glucosinolates which are derived from tryptophan. Implications for changes in the glucosinolate profile in rapeseed are discussed.     

Development and validation of gas chromatography and real‐time quantitative PCR for the quantification of landscape‐scale gene flow from varieties of high erucic acid (HEAR) oilseed rape

BACKGROUND: High erucic acid oilseed rape (HEAR) was tested as a source crop for estimates of regional geneflow. Two methods to detect HEAR in low erucic acid oilseed rape (LEAR) were compared: real‐time quantitative PCR (qPCR) and gas chromatography (GC). RESULTS: Fields (2.5 ha) of a LEAR variety (0.028% EA) in Tayside and Hertfordshire were juxtaposed adjacent to and 1 km distant from a HEAR (44% EA) field. The LEAR variety was a varietal association to ensure high cross‐pollination (CP). The methods were highly correlated, measuring between 30% and 0.5% CP. However, the qPCR method became unreliable below 0.5% CP, whereas GC was robust enough to detect raised EA equivalent to one F1 seed in 500 (0.2%). A statistical mixture model was fitted to the distributions of EA in samples in order to assign a CP value to each 500‐seed sample. Declines of CP from 30% to < 1%, and EA from 5% to 0.2%, with distance up to 150 m in the near fields was best fitted with a power function. The combined mean EA for both far fields was 0.11%, well above the background LEAR value of 0.028%, and mean CP was 0.36%. CONCLUSIONS: The GC method of detection raised %EA should be a reliable and high‐throughput means of estimating %CP between fields, provided the %EA of single F1 seed in receptor fields is measured to confirm the presence of F1 seed. Copyright © 2008 Society of Chemical Industry     

Glucosinolate profiles of international rapeseed lines (Brassica napus and Brassica campestris)

Seed samples from a range of international rapeseed lines (Brassica napus L and B campestris L) were analysed for glucosinolate content using high performance liquid chromatography (HPLC). This analytical method provided a total profile consisting of eight different glucosinolates, including those used to define the Canola standard. The data indicated that broad categories of distinct glucosinolate profiles existed among the seed lines analysed. Indole glucosinolate content, expressed as a percentage of total glucosinolate content, was higher in the low glucosinolate lines of B napus. The actual contents of all eight glucosinolates in the seed were variable, particularly gluconapin, glucobrassicanapin and progoitrin. The importance of this HPLC procedure in facilitating selection for high or low contents of individual glucosinolates is discussed.     

Effects of waterlogging at different stages of development on the growth and yield of winter oilseed rape (Brassica napus L.)

Oilseed rape, growing in a sandy loam soil in lysimeters, was subjected to waterlogging to the soil surface at different stages of growth. Brief periods of waterlogging in December and January (10 days) or in May (10 days) resulted in slightly shorter plants but hardly affected yield. Waterlogging in December/January for 6 weeks in cold (1–2°C) weather, slightly restricted leaf development and delayed flowering, but yield was unaffected. At the end of waterlogging for a similar duration between January and March (when the mean temperature was about 6°C), the height and leaf area of the plants was approximately halved, the number of senescent leaves was almost doubled and flowering was accelerated; at harvest in July these plants were 17% shorter and yields of seed, oil and straw were 14, 17 and 23% less, respectively, than for plants in freely-drained soil. During the prolonged waterloggings short fleshy white roots developed slightly below and on the soil surface.     

Solubility of a cruciferin‐rich protein product purified from rapeseed pressed cake (Brassica napus L.) by an aqueous processing method

Pressed cake from rapeseed (Brassica napus L.) is a promising plant protein source not yet utilised for human consumption due to the presence of antinutrients such as glucosinolates. Protein solubility is a crucial parameter influencing the functionality and thereby the applicability of proteins as food ingredients. A novel cruciferin‐rich rapeseed protein product was produced by an aqueous processing method in pilot plant scale. Intact glucosinolates were conserved by this procedure and largely removed from the protein products. Protein solubility in this product was examined when dispersed in 50 mm phosphate buffer, pH 8.0 with varying NaCl concentration (0–500 mm ). Unexpectedly, a salting‐out effect was observed of the globulin proteins, as 15.9 ± 0.6% protein was in solution at 500 mm added NaCl, whereas 21.5 ± 1.1% was solubilised without added NaCl; whether the observed effects originates from lipid and fibre constituents in the product remains to be resolved.     

施肥对贵州直播油菜产量和养分吸收的影响

2011-2012年于贵州省油菜主产区设置直播油菜氮磷钾硼肥田间试验,以推广品种油研599为材料,研究施肥对产量、养分累积量、肥料利用率及经济效益的影响,了解当地（典型的南方水稻土）的养分限制因子,为该地区直播油菜的合理施肥提供依据。结果表明,与不施肥相比,施肥提高了直播油菜的产量,各处理中以NPKB处理的产量最高,平均为2 189kg/hm2。缺氮、缺磷、缺钾和缺硼处理相比NPKB处理分别减产961、342、295和184kg/hm2,表明该地区直播油菜的养分限制因子依次为N〉P〉K〉B。与当地农民习惯施肥（FFP）相比,NPKB处理增加了施肥量,产量明显提升,平均增产430kg/hm2;养分累积量和肥料利用率也均有明显提高,氮、磷、钾及相应肥料利用率分别增加28.6kg/hm2和13.5%、9.6kg/hm2和3.3%、71.4kg/hm2和23.9%。从经济效益看,NPKB处理相比FFP处理收益平均增加1 109元/hm2。肥料合理配施可以明显提高直播油菜产量、养分累积和经济效益,在当前贵州省直播油菜的生产中,应积极推行合理的平衡施用技术和科学的施肥方法,从而达到高产、高效、高收益的目的。