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Effects of dietary lipids on the fatty acid composition of triglycerides and phospholipids in tissues of white sturgeon 总被引：1，自引：0，他引：1
Eight purified diets were fed to juvenile white sturgeon, Acipenser transmontanus Rick, for 9 weeks to investigate the effect of dietary lipids on the fatty acid composition of phospholipids and triglycerides from muscle, liver and brain. The diets contained 150 g kg?1 of oils from canola, corn, cod liver, lard, linseed, soybean, safflower, or a control mixture (corn oil/cod liver oil/lard, 1:1:1, by wt). Dietary lipids significantly (P≤ 05) affected the composition of tissue triglycerides and phospholipids. Tissue triglyceride fatty acid composition ranged widely, in parallel with the dietary lipids, while phospholipids changes were more conservative. Brain phospholipid fatty acid composition was less responsive to diet compared with that in muscle and liver. Considerable amounts of n-6 and n-3 long chain polyun-saturated fatty acids (> C20) were found in triglycerides and phospholipids with all diets, demonstrating that white sturgeon can desaturate and elongate linoleic acid (18:2n–6) and linolenic acid (18:3n–3). Further, the products of the Δ6 desaturase, i.e. 18:3 n–6 and 18:4n–3, were relatively abundant in triglyceride, suggesting that the Δ6 desaturase might not be a limiting step in the process in white sturgeon. Nevertheless, accumulation of both EPA and DHA was greater in the sturgeon fed fish oil than those fed linseed oil, indicating that muscle triglyceride EPA and DHA levels are best enhanced by diets rich in preformed EPA and DHA. 相似文献
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J.J. MA Z.R. XU Q.J. SHAO J.Z. XU SILAS S. O. HUNG W.L. HU L.Y. ZHUO 《Aquaculture Nutrition》2008,14(5):464-471
Effects of dietary l ‐carnitine were studied in juvenile black sea bream (Sparus macrocephalus). The semipurified basal diet [crude protein 450 g kg?1 dry matter (DM); crude lipid 126 g kg?1 DM] was formulated to choose white fishmeal as the protein source and fish oil plus corn oil (1 : 1) as the lipid source. Six diets (control + diets 1–5) containing 0.1, 0.12, 0.16, 0.24, 0.39 and 1.1 g of l ‐carnitine kg?1 diet were fed to triplicate groups of black sea bream (initial weight 13.10 ± 0.05 g) for 8 weeks. At the end of the feeding trial, growth performance, body composition and antioxidant status were determined. The results showed that relative growth rate (RGR) was significantly improved by the elevation of dietary l ‐carnitine level from 0.1 to 0.24 g kg?1, but decreased with further increment (P < 0.05). Lipid content decreased significantly (P < 0.05) in the dorsal muscle whereas increased (P < 0.05) in the liver with the addition of dietary l ‐carnitine. Dietary l ‐carnitine supplements elevated enzymatic antioxidants (superoxide dismutase, SOD; catalase, CAT; glutathione‐S‐transferase, GST) activities (P < 0.05) yet decreased the content of non‐enzymatic factor, total sulphydryl groups (TSH) (P < 0.05). In summary, the optimum dietary l ‐carnitine level was 0.284 g kg?1 diet by second‐polynomial regression analysis based on RGR (y = ?647.4x2 +367.97x + 234.55; R2 = 0.977, x = dietary l ‐carnitine levels, y = RGR), and dietary l ‐carnitine addition within the levels adopted in our study could depress lipid peroxidation in tissues of juvenile black sea bream. 相似文献
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ABSTRACT: The reproductive value and population status of the big eye in the north-eastern Taiwan waters was estimated by demographic analysis using available life-history parameters. Life-history tables were constructed using estimates of natural mortality ( M ) of 10.4920/year for age 0 and 0.3256/year for ages 1–9, with a maximum age of 9. Age-specific batch fecundity ( Fe ) was from Fe = 1391.34e0.1782 FL . The age-specific proportion of maturity was estimated from the relationship between the proportion of female maturity ( Pr ) and fork length ( FL ): Pr = 1/(1 + e15.081−0.796 FL ). Females mature at age 3 and mature females reproduce every year. The population increase rate (λ) was estimated to be 20.5% per year and the generation time ( G ) was 6.25 years without exploitation. The net reproductive value ( R0 ), generation time and intrinsic rate of natural increase ( r ) decreased with increased fishing mortality. For fixed fishing mortality, when F = 1.2/year and fishing started at age 3, R0 was estimated to be 1.0 and the population was considered to be in equilibrium. For age-specific fishing mortality, when fishing started at age 3, R0 was estimated to be 0.96/year, G being 6.18 years, and the population decreased 0.7% per year. The big eye population had a strong resilience as long as F < = 1.3/year started at an age that was older than the age at maturity (i.e. 3 years old) but would decline when intensive fishing ( F > = 1.2/year) started at age 2 or younger. Sensitivity analysis indicated that the mortality of age 0 is the most sensitive parameter in demographic analysis. 相似文献
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复合生物杀虫剂防治刚竹毒蛾研究 总被引：11，自引：0，他引：11
应用苏云金杆菌 80 1 0、白僵菌建瓯菌株、保丰 3种杀虫剂对 2～ 3龄刚竹毒蛾幼虫进行毒力测定 ,筛选出复合生物杀虫剂最佳组合为苏云金杆菌 1 .6× 1 0 6个孢子 / m L+白僵菌 1 .4× 1 0 6个孢子 / m L+保丰 60 0 0倍液 .应用复合生物杀虫剂与低浓度的 2 0 %杀灭菊酯混合 ,分别对2～ 3龄幼虫进行毒力测定和林间防治试验 ,试验表明 :苏云金杆菌 1 .6× 1 0 7个孢子 / m L+白僵菌 1 .4× 1 0 8个孢子 / m L+保丰 40 0 0倍液 +杀灭菊酯 1 0 0 0 0倍液为林间防治 2～ 3龄幼虫的最佳组合 ;复合生物杀虫剂添加低浓度的杀灭菊酯有一定的增效作用 相似文献
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小麦×玉米诱导小麦单倍体高效系统的建立 总被引：4，自引：3，他引：4
为建立一套高效的小麦×玉米单倍体诱导系统用于构建小麦DH群体,采用杂交后剪穗进行人工控制环境条件的室内离体培养法和田间常规杂交法诱导小麦×玉米单倍体,研究了不同培养环境、离体培养时环境温度、常规杂交法时T>10℃有效积温对单倍体成胚率和成苗率的影响。结果表明:就平均成胚率而言,离体培养法(23.6%)>常规杂交法(18.1%),获得最高成胚率的环境温度为21℃~23℃,T>10℃有效积温为188℃;就平均成苗率而言,离体培养法(18.7%)高于常规杂交法(15.1%),获得最高成苗率的环境温度为23℃,T>10℃有效积温为188℃。并在此基础上建立了一套高效、可靠、重复性好的小麦×玉米单倍体诱导系统。实验还表明大田条件下,授粉后12~14d的培养时间不宜作为小麦×玉米单倍体剥胚的时间标准,而应以授粉后外界环境提供的T>10℃有效积温作为剥胚的时间标准可能更准确。 相似文献
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为了提高并稳定转基因胚胎移植受胎率,对可能影响受胎率的供受体同期化程度、移植胚胎数量、受体处理方式、胚胎发育速度、受体注射黄体酮、供体作受体等6个方面进行研究。结果表明,(1)供受体发情时间差在±12h以内,不影响受胎率(P>0.05);(2)每只受体移植2～3枚转基因胚胎的受胎率极显著高于移植1枚的受胎率(P<0.01);(3)在繁殖季节里,受体采用自然发情、肌肉注射PGF2α、肌肉注射PMSG+PGF2α等方式,三者受胎率间差异不显著(P>0.05);(4)发育迟缓的胚胎移植后,受胎率显著低于正常发育胚胎的受胎率(P<0.01);(5)移植后的受体注射2mg黄体酮,不能提高受胎率(P>0.05);(6)供体当作受体使用,不影响受胎率(P>0.05)。 相似文献
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Effect of oxidized fish oil, vitamin E and ethoxyquin on the histopathology and haematology of rainbow trout, Salmo gairdneri Richardson 总被引：3，自引：0，他引：3
Abstract. Rainbow trout were fed for 24 weeks on practical diets containing varying concentrations of oxidized fish oil, with or without supplementation of vitamin E and ethoxyquin. Serum biochemistry, haematology and histopathology were investigated to measure the relative protection offered by vitamin E (DL–α–toco–pherol acetate) and/or a synthetic substitute (ethoxyquin), against highly or extremely oxidized oil with peroxide values of 120 or 314mEq/kg oil respectively. Groups fed highly or extremely oxidized oils without DL–α–tocopherol acetate supplementation, and with or without supplemental ethoxyquin, exhibited lower red blood cell numbers, haemoglobin content, haematocrit, and increased haemolysis. In addition, fish from these groups had increased, abnormally developing polychromatocytes, splenic haemosiderosis and hepatic ceroidosis. The results indicate that vitamin E protects better and at lower concentrations than does ethoxyquin, and that supplementation with 33 mg of DL–α–tocopherol acetate/kg is adequate to prevent vitamin E deficiency signs when feeding practical diets containing 7.5 % of a highly oxidized oil. Supplementation with ethoxyquin alone to diets containing highly oxidized oil appeared to exert partial protection, but did not increase the level of protection when added simultaneously with DL–α–tocopherol acetate. The data support the theory of a general antioxidant function for vitamin E, and suggest that mortalities ensuing from vitamin E deficiency are due to the cumulative effects of liver dysfunction and anaemia. 相似文献
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甜菜色素在自然界中与花青素排斥分布,主要在石竹目（Caryophyllales）的9个科的植物中合成。虽然甜菜色素的生物合成已经有很多猜测,酶催化的生物合成关键步骤仍然缺少足够的实验数据支持。本研究首先从三角梅属的3个种（B. spectabilis‘Splendens’,B. buttiana‘Mahara’,B. pruviana‘Thimma’）的苞片中分离了甜菜色素合成途径末端的关键酶4,5-DOPA-dioxygenase完整的cDNA,大小分别为902、899、899 bp,分别编码298、297、297个氨基酸,并对这3个同源基因与已经报道的来自B. glabra的该基因进行比较。推测的分子量分别为33 758、33 076、33 233 u,等电点（pI）分别是5.62、5.54和5.94。对分属于4个种（B.spectabilis‘Splendens’,B. buttiana‘Mahara’,B. glabra‘Alba’,B. pruviana‘Thimma’）花的4,5-DOPA-dioxygenase的Real-time分析结果表明,该基因在4个种的花中,种间变化较大,总体趋势是开花早期该基因的表达较弱,盛花期表达迅速增强,后期又呈现下降。其中,在红色的B.buttiana‘Mahara’中,该基因的表达最强,在白色的B.glabra‘Alba’中表达最弱。这些结果表明,该基因的表达与花的颜色鲜艳程度直接相关。 相似文献