Effects of post‐grazing herbage height and concentrate feeding on milk production and major milk fatty acids of dairy cows in mid‐lactation

Milk fatty acids (FA) were compared in mid‐lactation dairy cows in four feeding systems combining grazing management and supplementation. The four treatments were factorial combinations of compressed herbage grazed to 3·7 or 4·6 cm post‐grazing height, with or without concentrate feeding (3·6 kg cow^?1 d^?1). Milk yield and composition were measured for four groups of eight Friesian × Jersey dairy cows over 3 weeks in mid‐lactation for cows that had grazed treatments for 64 d from early spring. Milk yield was higher in cows fed concentrate plus herbage (23·9 kg d^?1 cow^?1) than cows fed herbage only (20·3 kg d^?1 cow^?1). Milk fat percentage was higher in cows fed herbage only (5·5%) than that fed herbage plus concentrate (5·1%). Milk protein percentage was higher in cows fed herbage plus concentrate (4·0%) than that fed herbage only (3·7%). The concentrations of conjugated linoleic acids c9, t11, C18:0, C18:1 t11 and C18:2 t9, c12 FA were lower where concentrate was fed. The concentrations of C18:1 t10, C18:1 t5, t8 and C18:2 c9, c12 FA were higher where concentrate was fed. The concentrations of C18:1 c6, C18:1 c9, C18:1 t9 and C18:3 c6,9,15 were unaffected by concentrate feeding. Post‐grazing herbage height had no significant effect on milk yield or concentration of milk FA. Provided dairy cows are harvesting leafy material of similar nutrient and FA concentration, post‐grazing herbage height does not appear to alter milk FA and the supply of high energy concentrates is more influential on milk FA profiles.     

灰色关联分析法对叶用莴苣生长期光环境的优化

为保证设施叶用莴苣周年生产的供给,研究了人工气候条件下不同光照模式对叶用莴苣生长期生长特性的影响,以确定叶用莴苣生长的最优光环境,实验以‘意大利’全年耐抽薹叶用莴苣（Lactuca sativa L.）为试材,设计 LED 红蓝配比（7:3、5:5、3:7）、光周期（12L/12D、16L/8D、20L/4D）及光照强度[100 μmol/(m2·s)、150 μmol/(m2·s)、200 μmol/(m2·s)]的 3 因素 3 水平正交实验,利用灰色关联分析法分析不同光照模式对生长期叶用莴苣植株的生长、光合色素含量及营养品质的影响。结果表明,不同处理对叶用莴苣生长期生长及品质的影响不同。相比于其他光环境条件,处理 9[红蓝配比 3:7,光周期 20L/4D,光强 150 μmol/(m2·s)]更有利于光合色素的积累。红蓝配比 3:7 的光照模式较其他处理更有利于蛋白质合成;处理 3[红蓝配比 7:3,光周期 20L/4D,光强 200 μmol/(m2·s)]有利于降低生长期叶用莴苣叶片硝态氮含量,促进可溶性糖的积累。综合分析得出 3 个光照因子对水培叶用莴苣生长及品质影响的重要程度依次为：光强、光质配比、光周期,最适的光照模式组合为：红蓝配比 7:3、光强 200 μmol/(m2·s)、光周期 20L/4D。本研究结果可为叶用莴苣生长的最适光环境提供参考,同时为 LED 灯具在植物照明领域的设计提供 技术支持。     

Influence of herbage species, cultivar and cutting date on fatty acid composition of herbage and lipid metabolism during ensiling

The fatty acid (FA) concentration of herbage and lipid metabolism in silage, mainly oxidation and lipolysis, of different species (perennial ryegrass, red clover and white clover) and three cultivars of white and red clover at three cutting dates in the growing season (April, July and October) were studied. FA concentration and composition was strongly affected by species and cutting date. Perennial ryegrass had lower concentrations of C16:1, C18:0, C18:1 and C18:2 than red and white clover. Within red and white clover, the effect of cultivar was small. Oxidation of C18:3 during wilting was different between species and cutting date despite similar wilting conditions. Lipolysis in silage was also influenced by cutting date, species and to some extent by cultivar. Furthermore, in some cuts silages of red and white clover displayed a lower lipolysis than silage of perennial ryegrass. On average, over the three cutting dates proportionately 0·903, 0·864 and 0·857 of the membrane lipids in perennial ryegrass, red clover and white clover were hydrolysed during ensiling. In red clover this could be due to the lipid-protecting properties of polyphenol oxidase (PPO) activity. This was not observed in perennial ryegrass or white clover. Nevertheless, differences in lipolysis in silage between cultivars of red clover were not correlated with PPO activity.     

Multiple Beneficial Health Effects of Natural Alkylglycerols from Shark Liver Oil

Alkylglycerols (alkyl-Gro) are ether lipids abundant in the liver of some elasmobranch fish species such as ratfishes and some sharks. Shark liver oil from Centrophorus squamosus (SLO), or alkyl-Gro mix from this source, have several in vivo biological activities including stimulation of hematopoiesis and immunological defences, sperm quality improvement, or anti-tumor and anti-metastasis activities. Several mechanisms are suggested for these multiple activities, resulting from incorporation of alkyl-Gro into membrane phospholipids, and lipid signaling interactions. Natural alkyl-Gro mix from SLO contains several alkyl-Gro, varying by chain length and unsaturation. Six prominent constituents of natural alkyl-Gro mix, namely 12:0, 14:0, 16:0, 18:0, 16:1 n-7, and 18:1 n-9 alkyl-Gro, were synthesized and tested for anti-tumor and anti-metastatic activities on a model of grafted tumor in mice (3LL cells). 16:1 and 18:1 alkyl-Gro showed strong activity in reducing lung metastasis number, while saturated alkyl- Gro had weaker (16:0) or no (12:0, 14:0, 18:0) effect. Multiple compounds and mechanisms are probably involved in the multiple activities of natural alkyl-Gro.     

温度、光照和土壤含水量对大豆胞囊线虫休眠卵孵化的影响

研究在实验室条件下不同温度,不同光照和不同土壤含水量对大豆胞囊线虫(SCN)休眠卵孵化的影响.分别测定了5个温度梯度下(18℃、21℃、24℃、27℃和30℃),7个光照条件下(0/24 h,4/20 h,8/16 h,12/12 h,16/8h,20/4 h和24/0 h)和7个土壤含水量(1%、5%、10%、15%、20%、25%和30%)条件下SCN休眠卵的孵化情况.结果表明:在供试温度18～30℃之间,休眠卵的孵化总量随温度升高而增加,30℃下孵化数量最大,达1316.33条.全光照处理的孵化量最大,达745.00条,4L/20D、12L/12D和20L/4D次之,而全黑暗处理的孵化量最少,仅为102.00条.土壤含水量在1%～30%之间,含水量为15%时孵化数量最大,达265.33,含水量在1%～15%时,孵化量随含水量的增加而增加,当含水量大于15%时,孵化量随含水量增加反而降低.研究证实在SCN休眠期可以通过提高温度增加光照时间来诱导卵孵化,以提高J2孵化数量,采用休眠胞囊接种应注意调节土壤含水量.     

Bioactive Lipids of Marine Microalga Chlorococcum sp. SABC 012504 with Anti-Inflammatory and Anti-Thrombotic Activities

Microalgae are at the start of the food chain, and many are known producers of a significant amount of lipids with essential fatty acids. However, the bioactivity of microalgal lipids for anti-inflammatory and antithrombotic activities have rarely been investigated. Therefore, for a sustainable source of the above bioactive lipids, the present study was undertaken. The total lipids of microalga Chlorococcum sp., isolated from the Irish coast, were fractionated into neutral-, glyco-, and phospho-lipids, and were tested in vitro for their anti-inflammatory and antithrombotic activities. All tested lipid fractions showed strong anti-platelet-activating factor (PAF) and antithrombin activities in human platelets (half maximal inhibitory concentration (IC₅₀) values ranging ~25–200 μg of lipid) with the highest activities in glyco- and phospho-lipid fractions. The structural analysis of the bioactive lipid fraction-2 revealed the presence of specific sulfoquinovosyl diacylglycerols (SQDG) bioactive molecules and the HexCer-t36:2 (t18:1/18:1 and 18:2/18:0) cerebrosides with a phytosphingosine (4-hydrosphinganine) base, while fraction-3 contained bioactive phosphatidylcholine (PC) and phosphatidylethanolamine (PE) molecules. These novel bioactive lipids of Chlorococcum sp. with putative health benefits may indicate that marine microalgae can be a sustainable alternative source for bioactive lipids production for food supplements and nutraceutical applications. However, further studies are required towards the commercial technology pathways development and biosafety analysis for the use of the microalga.     

Influence of Environmental Factors on the Paralytic Shellfish Toxin Content and Profile of Alexandrium catenella (Dinophyceae) Isolated from the Mediterranean Sea

Laboratory experiments were designed to study the toxin content and profile of the Alexandrium catenella strain ACT03 (isolated from Thau Lagoon, French Mediterranean) in response to abiotic environmental factors under nutrient-replete conditions. This dinoflagellate can produce various paralytic shellfish toxins with concentrations ranging from 2.9 to 50.3 fmol/cell. The toxin profile was characterized by carbamate toxins (GTX3, GTX4 and GTX5) and N-sulfocarbamoyl toxins (C1, C2, C3 and C4). C2 dominated at 12–18 °C, but only for salinities ranging from 10 to 25 psu, whereas GTX5 became dominant at temperatures ranging from 21 to 30 °C at almost all salinities. There was no significant variation in the cellular toxin amount from 18 °C to 27 °C for salinities ranging between 30 and 40 psu. At salinities of 10 to 25 psu, the toxin concentrations always remained below 20 fmol/cell. Toxin content was stable for irradiance ranging from 10 to 70 μmol photons/m²/s then slightly increased. Overall, the toxin profile was more stable than the toxin content (fmol/cell), except for temperature and/or salinity values different from those recorded during Alexandrium blooms in Thau Lagoon.     

生菜苗期生长最优光照模式的模糊综合评判

为探讨不同光照模式对生菜苗期生长和品质的影响,以荧光灯为对照（CK）,采用发光二极管（LED）调控光谱能量分布,设计LED红蓝配比（7:3、5:5、3:7）、光周期（12L/12D、16L/8D、20L/4D）及光照强度(100、150、200μmol·m-2·s-1)3因素3水平的正交试验,共9个试验处理组。以"意大利"全年耐抽薹生菜为材料,测定苗期生长和品质相关的指标,采用层次分析法（AHP）确定各生长和生理指标的权数,通过模糊数学原理对生菜苗期生长进行综合评价分析。结果表明:生菜苗期株高、茎粗、下胚轴长、整株鲜重、叶绿素、可溶性糖、可溶性蛋白质和硝酸盐的权重依次为0.101 8、0.046 6、0.078 0、0.273 6、0.148 7、0.054 8、0.054 8和0.241 8。综合评价结果为红蓝配比为5:5、光周期为20L/4D、光强为100μmol·m-2·s-1的光照模式栽培效果最好,其次是红蓝配比为7:3、光周期为20L/4D、光强为200μmol·m-2·s-1的光照模式。层次分析法对生菜不同光照模式的栽培效果的综合评价有较好的适应性,有助于获得南方设施工厂化生菜育苗最佳的光照模式。     

Fatty Acid Production and Direct Acyl Transfer through Polar Lipids Control TAG Biosynthesis during Nitrogen Deprivation in the Halotolerant Alga Dunaliella tertiolecta

The aims of this work were to evaluate the contribution of the free fatty acid (FA) pool to triacylglyceride (TAG) biosynthesis and to try to characterize the mechanism by which FA are assimilated into TAG in the green alga Dunaliella tertiolecta. A time-resolved lipidomic analysis showed that nitrogen (N) deprivation induces a redistribution of total lipidome, particularly of free FA and major polar lipid (PL), in parallel to enhanced accumulation of polyunsaturated TAG. The steady-state concentration of the FA pool, measured by prolonged ¹⁴C-bicarbonate pre-labeling, showed that N deprivation induced a 50% decrease in total FA level within the first 24 h and up to 85% after 96 h. The abundance of oleic acid increased from 50 to 70% of total free FA while polyunsaturated FA (PUFA) disappeared under N deprivation. The FA flux, measured by the rate of incorporation of ¹⁴C-palmitic acid (PlA), suggests partial suppression of phosphatidylcholine (PC) acyl editing and an enhanced turnover of the FA pool and of total digalactosyl-diacylglycerol (DGDG) during N deprivation. Taken together, these results imply that FA biosynthesis is a major rate-controlling stage in TAG biosynthesis in D. tertiolecta and that acyl transfer through PL such as PC and DGDG is the major FA assimilation pathway into TAG in that alga and possibly in other green microalgae. Increasing the availability of FA could lead to enhanced TAG biosynthesis and to improved production of high-value products from microalgae.     

Planting date and development of spring-seeded irrigated canola, brown mustard and camelina

With increased emphasis on bio-diesel fuels, the influence of spring planting on development of brown mustard (Brassica juncea cv. Arid), canola (B. napus cv. Hyola 401) and camelina (Camelina sativa cv. Boa) has become important. Field trials were conducted at Scottsbluff, NE, in 2005 and 2006 at planting dates of 24 February, 24 March, 7 April, 21 April and 5 May, and 3 March, 3 April, 10 April, 27 April, 11 May, and 2 Jun, respectively. Emergence time was shorter with later planting. Flowering date was later with later planting but occurred within a range of degree days (P-days). Fruiting was affected by date and P-days, but seed maturity was not affected by planting date and was unrelated to P-days. Fleabeetle (Phyllotreta spp.) damage was very high in brown mustard and canola. Bird, primarily house finch (Carppodacus mexicanus), feeding was a major problem with brown mustard planted before mid April and in canola, only with the first planting. Camelina was not affected by either. Planting in April gave the best yields, and canola could yield over 2200 kg ha⁻¹. Oil content of the Brassica was highest when planted from late March and later. For camelina, planting date had no effect. In brown mustard and canola, 60-65% of oil was C18:1, in camelina, about 15%. Later planting increased C18:1 content for the three crops. The second fatty acid was C18:2 with 20% in brown mustard, 18% in canola and 20% in camelina. Later planting increased C18:2 in camelina only. The major fatty acid in camelina was C18:3 at 32-37%; earlier planting increased the content of C18:3. In Camelina, C20:1 comprised about 12% of the oil and was highest with April planting. Canola and camelina seeded in April could be grown for oil successfully in western Nebraska.     

A 13CO2 Enrichment Experiment to Study the Synthesis Pathways of Polyunsaturated Fatty Acids of the Haptophyte Tisochrysis lutea

The production of polyunsaturated fatty acids (PUFA) in Tisochrysis lutea was studied using the gradual incorporation of a ¹³C-enriched isotopic marker, ¹³CO₂, for 24 h during the exponential growth of the algae. The ¹³C enrichment of eleven fatty acids was followed to understand the synthetic pathways the most likely to form the essential polyunsaturated fatty acids 20:5n-3 (EPA) and 22:6n-3 (DHA) in T. lutea. The fatty acids 16:0, 18:1n-9 + 18:3n-3, 18:2n-6, and 22:5n-6 were the most enriched in ¹³C. On the contrary, 18:4n-3 and 18:5n-3 were the least enriched in ¹³C after long chain polyunsaturated fatty acids such as 20:5n-3 or 22:5n-3. The algae appeared to use different routes in parallel to form its polyunsaturated fatty acids. The use of the PKS pathway was hypothesized for polyunsaturated fatty acids with n-6 configuration (such as 22:5n-6) but might also exist for n-3 PUFA (especially 20:5n-3). With regard to the conventional n-3 PUFA pathway, Δ6 desaturation of 18:3n-3 appeared to be the most limiting step for T. lutea, “stopping” at the synthesis of 18:4n-3 and 18:5n-3. These two fatty acids were hypothesized to not undergo any further reaction of elongation and desaturation after being formed and were therefore considered “end-products”. To circumvent this limiting synthetic route, Tisochrysis lutea seemed to have developed an alternative route via Δ8 desaturation to produce longer chain fatty acids such as 20:5n-3 and 22:5n-3. 22:6n-3 presented a lower enrichment and appeared to be produced by a combination of different pathways: the conventional n-3 PUFA pathway by desaturation of 22:5n-3, the alternative route of ω-3 desaturase using 22:5n-6 as precursor, and possibly the PKS pathway. In this study, PKS synthesis looked particularly effective for producing long chain polyunsaturated fatty acids. The rate of enrichment of these compounds hypothetically synthesized by PKS is remarkably fast, making undetectable the ¹³C incorporation into their precursors. Finally, we identified a protein cluster gathering PKS sequences of proteins that are hypothesized allowing n-3 PUFA synthesis.     

Microalgae as Sustainable Bio-Factories of Healthy Lipids: Evaluating Fatty Acid Content and Antioxidant Activity

The demand for sustainable and environmentally friendly food sources and food ingredients is increasing, and microalgae are promoted as a sustainable source of essential and bioactive lipids, with high levels of omega-3 fatty acids (ω-3 FA), comparable to those of fish. However, most FA screening studies on algae are scattered or use different methodologies, preventing a true comparison of its content between microalgae. In this work, we used gas-chromatography mass-spectrometry (GC-MS) to characterize the FA profile of seven different commercial microalgae with biotechnological applications (Chlorella vulgaris, Chlorococcum amblystomatis, Scenedesmus obliquus, Tetraselmis chui, Phaeodactylum tricornutum, Spirulina sp., and Nannochloropsis oceanica). Screening for antioxidant activity was also performed to understand the relationship between FA profile and bioactivity. Microalgae exhibited specific FA profiles with a different composition, namely in the ω-3 FA profile, but with species of the same phylum showing similar tendencies. The different lipid extracts showed similar antioxidant activities, but with a low activity of the extracts of Nannochloropsis oceanica. Overall, this study provides a direct comparison of FA profiles between microalgae species, supporting the role of these species as alternative, sustainable, and healthy sources of essential lipids.     

Influence of cultivar and cutting date on the fatty acid composition of perennial ryegrass (Lolium perenne L.)

Two experiments were conducted to evaluate the effects of cultivar and season on the fatty acid (FA) composition of the lipids of perennial ryegrass (Lolium perenne L.). Eight diploid cultivars were cut at the same target yield of approximately 2000 kg dry matter ha^?1 between mid‐June and mid‐September. Two cultivars (Barlet and Magella) were harvested during four 2‐week periods and six cultivars (AberGold, Respect, Agri, Herbie, Barezane and Barnhem; cultivars 1–6) during three periods. The concentrations of individual FA were determined by gas chromatography. Barlet had higher concentrations of linolenic acid (C18:3) than Magella, but lower concentrations of linoleic acid (C18:2). Cultivars 1–6 were more variable in their leaf blade and stem proportions than Barlet and Magella. Despite this, there was no difference between cultivars 1–6 in the FA composition of the herbage. On average 0·74 of the FA consisted of C18:3. Higher concentrations of total FA were found in mid‐summer than in early summer. This was related to a high leaf blade proportion in the herbage, indicating that the proportion of leaf and stem of the herbage probably had more effect on lipid concentrations than the season per se in this period. However, in late August and mid‐September, the total FA concentration declined whereas the leaf blade proportion increased. Therefore, in this period environmental factors appeared to have a modifying effect. As consistent differences in the concentration of C18:3 were found among cultivars Barlet and Magella throughout the season, these studies demonstrate opportunities to change the composition of ruminant products through the choice of cultivars of perennial ryegrass.     

不同梯度光照强度对黄瓜嫁接苗愈合及幼苗质量影响

为探究黄瓜嫁接苗愈合及幼苗生长的最佳光照模式,本研究选择南瓜‘壮士’品种为砧木,黄瓜‘大棚冬青’品种为接穗,顶插嫁接后0~3、4~6、7~10 d为阶段性递增光照模式,以(0-30-45) μmol/(m²·s)为对照（CK）,设[(15-30-45)、(30-60-90)、(45-90-135)、(60-120-180)、(75-150-225) μmol/(m²·s)]分别为T1、T2、T3、T4和T5处理,研究不同梯度光照强度对黄瓜嫁接苗愈合生长及幼苗质量的影响。结果表明,与CK相比,嫁接后0~3 d适宜光照优于黑暗条件,光照强度梯度在处理T2~T5之间时,能显著提高接合部愈合效果（P<0.05）;其中T3处理最有利于黄瓜嫁接苗愈合及生长,其地上部、地下部形态生长指标最佳,最有利于促进黄瓜嫁接苗雌花分化和早熟;T3与T4处理幼苗真叶生长势较优,而T2与T3处理有利于嫁接苗光合色素含量的增加;运用隶属函数值法进行综合分析,各处理下隶属函数综合评价值大小排名为：T3>T2>T4>T5>T1>CK。综合分析得出,T3处理即嫁接后0~3、4~6、7~10 d的光强梯度为(45-90-135) μmol/(m²·s),最有利于黄瓜嫁接苗的愈合生长及幼苗质量的提高,故T3梯度光照强度可作为黄瓜嫁接苗愈合期处理的最适光强模式。     

Combination of high-speed countercurrent chromatography and reversed phase C18 chromatography for large-scale isolation of cyanidin-3-O-β-d-glucoside from black rice bran extract

Cyanidin-3-O-β-d-glucoside (C3G), the best known and most investigated anthocyanin, has many pharmacological properties. Black rice bran is an outstanding source for the separation of C3G due to its high C3G content and a simple anthocyanin composition. The present study described a large-scale isolation of C3G from the crude black rice bran extract by combining high-speed countercurrent chromatography (HSCCC) and reversed phase C₁₈ column chromatography. After HSCCC enrichment with the solvent system water-n-butanol-tert-butyl-methyl-ether (TBME)-acetonitrile-trifluoroacetic acid (TFA) (5:2:2:1:0.1%), the C3G content was concentrated about 16-fold and reached to 563.23 mg/g with a recovery 96.89%. Further purification was carried out using reversed phase C₁₈ column chromatography and 1.43 g of pure C3G (purity 94.38%) was obtained from 3.0 g of anthocyanin-enriched extract. The method is time-saving, low risk of sample denaturation, high sample recovery, and so is suitable for large-scale preparation of C3G for further studies of bioactivities.     

Lipid composition and deposition during grain filling in intact barley (Hordeum vulgare) mutant grains as studied by H HR MAS NMR

Conventional barley has an excellent nutritional value, but a lower content of lipids than oat. Nevertheless, barley lipids deserve a focused interest due to their fatty acid composition and their vitamin E composition. In this study, ¹H HR MAS NMR was used to monitor the deposition of lipids during grain filling of conventional barley, and of two barley endosperm mutants with increased lipid content. The lipids in the mutants are primarily synthesized between days 9 and 13, whereas the lipid biosynthesis in the conventional barley took place ten days later. GC analysis on barley flour lipids showed that the mutants and the control exhibit comparable relative levels of the major fatty acids: C16:0, C18:1 and C18:2 despite the higher content of lipids in the mutants. Differences in the minor fatty acid composition between control and mutants were also observed. The degree of unsaturation was found to be increasing during grain filling for both conventional barley and the two mutants.     

Variation in polar lipids located on the surface of wheat starch

It is unknown whether starch isolated before dough development has the same surface lipid composition as starch isolated after dough development. The abundance of starch surface polar lipids is related to the physical hardness of the endosperm, but the variation in specific lipid classes and molecular species is unknown. The objective of this study was to determine the variation in polar lipids present on the surface of wheat starch granules. The experimental wheat lines used are, within each set, near-isogenic to each other but vary in endosperm hardness. Starch was isolated using two different processes: a dough and a batter method. Direct infusion electrospray ionization tandem mass spectrometry was used to identify and quantitatively determine the polar lipid species in wheat flour and on starch. Wide ranges in starch surface polar lipid concentrations were observed between the starch isolation methods. Starch isolation method provided a greater source of variation than did wheat kernel hardness. When dough is optimally mixed, lipids originally on the surface of wheat starch are dissociated, whereas in a batter system, starch surface lipids stay associated with the starch surface. The predominant starch surface polar lipids were digalactosyldigylcerol (DGDG), monogalactosyldigylcerol (MGDG) and phosphatidylcholine (PC) polar lipid classes.     

Unusual Ether Lipids and Branched Chain Fatty Acids in Sea Cucumber (Cucumaria frondosa) Viscera and Their Seasonal Variation

The sea cucumber, Cucumaria frondosa, is harvested primarily for its muscular bands and body wall. Development of a nutraceutical product based on lipid recovered from its viscera would give commercial value to the entire organism; however, such development requires knowledge of the lipid and fatty acid (FA) profiles of the viscera. Here, we describe the lipid and FA composition of viscera recovered from C. frondosa harvested in coastal waters in the northwest Atlantic, taking into account variation due to harvest season. We found highest lipid content at ~29% in winter, with diacylglyceryl ethers (DAGE) comprising ~55% of the total lipid mass and triacylglycerols (TAG), phospholipids (PL) and monoacylglycerol ethers (MAGE) at 5–25% each. The branched chain FA, 12-methyltetradecanoic acid (12-MTA), represented 42% of total FA mass in DAGE. In summer, lipid content was lower at 24% and TAG was the dominate lipid, with proportions more than double that found in winter (45% vs. 20%); DAGE in summer dropped to ~30% of total lipids. In TAG, 12-MTA was much lower than found in DAGE in winter, at only 10% but eicosapentaenoic acid (EPA) content was ~20%, which brought the total EPA% to 28% of total FA—the highest among all three seasons. There was little effect of season on MAGE or PL proportions. These data can help harvesters maximize catch efforts in terms of lipid yield and profile.     

Vernonia galamensis,a natural source of epoxy oil: variation in fatty acid composition of seed and leaf lipids

Vernonia galamensis is a new potential industrial oilseed crop with origin in East Africa. The seed oil has unique chemical and physical properties, that will permit its use in the formulation of reactive diluents, products to serve as solvents that become part of the dry paint surface and do not evaporate to pollute the air. A collection of 41 accessions was evaluated for seed and leaf fatty acid composition. In the seed, vernolic acid (C18:10) varied from 54 to 74%, and linoleic acid (C18:2) from 3 to 32%. In the leaf linolenic acid (C18:3) varied from 41 to 59%, palmitic (C16:0) from 12 to 22% and C18:4 from 8 to 17%. Correlation analysis between the seed fatty acids showed that vernolic acid is negatively correlated with C16:0, C18:0, C18:2, C18:3. In the leaf, negative correlations between C18:3 and the other leaf fatty acids were observed. C18:2 and C18:3 showed negative and positive correlations, respectively between the leaves and the seed. In general, there is a wide range of fatty acid composition specially vernolic and linolenic acids in the seed and in the leaf, respectively which might indicate the potential for oil quality improvement of V. galamensis.     

Allele and isozyme patterns of UDP-glucose pyrophosphorylase as a marker for cold-sweetening resistance in potatoes

Uridine-5-’diphosphoglucose pyrophosphorylase (UTP α-D-glucose-l-phosphate uridylyltransferase, E.C. 2.7.7.9) (UGPase) was cloned from 16 potato cultivars(Solanum tuberosum L.) that differed in their ability to accumulate reducing sugars in cold storage (3 C) using RT-PCR. Two UGPase-alleles designatedas UgpA (minus a BamHl site) and UgpB (containing oneBamHl site), were present in most cultivars. Cultivars that were cold-resistant (CR) to sweetening demonstrated an UgpA:UgpB ratio favoring the UgpA allele (4:0 or 3:1), while cultivars that were cold-sensitive (CS) exhibited a predominance for the UgpB allele (1:3 or 0:4). Following cold-storage at 3 C for two months, the CR and CS clones accumulated 10.3 ± 2.1 and 31.2 ± 2.2 umol glucose/g FW, respectively. The glucose content and chip color between the CR and CS clones were significantly different at the 99% level of confidence. Staining for UGPase activity in nondenaturing polyacrylamide gels of proteins extracted from CS potatoes revealed up to three acidic isozymes of UGPase (i.e., UGP1, UGP2, UGP3) with UGP3 being the most abundant. Activity staining using CR cultivars demonstrated two additional isozymes of UGPase with greater electrophoretic mobility (more basic in charge) which were designated UGP4 and UGP5. The potential for using UGPase allelic ratios and/or UGPase isozymic patterns as a selective tool to screen segregating progeny in a potato breeding program for cold-sweetening-resistant germplasm is discussed.