Dietary nucleotide mixture effects on reproductive and performance,ovary fatty acid profile and biochemical parameters of female Pacific shrimp Litopenaeus vannamei

The effects of different dietary nucleotide mixture (NT) levels (0, 2, 4 and 6 g/kg) were investigated on the reproductive performance, fatty acid profile and biochemical parameters in Litopenaeus vannamei female that were co‐fed with fresh food (two times daily) and experimental diets (two times daily) for 30 days. Sampling was carried out at the first day of the trial, before eyestalk ablation (ESA) (day 21) and after ESA (day 30). Reproductive performance parameters including the hepatopancreatic index, absolute fecundity, egg diameter and latency period were higher in the NT‐supplemented groups than the control group (p < .05). Total n‐3 polyunsaturated fatty acids in the ovaries, especially eicosapentaenoic acid, were higher in the NT‐supplemented groups than in the control (222.6 ± 7.3 versus 204.7 ± 3.0 mg/g extracted lipid) (p < .05). Total hemocyte count, granular cells, plasma glucose (Glu), total protein (TP), calcium (Ca²⁺), total cholesterol (Chol), triglyceride (Tg) and high‐density lipoprotein (HDL) levels were significantly increased in the NT‐supplemented groups in comparison with the control group (p < .05). After ESA, the concentration of plasma Glu, TP, Chol and Tg significantly decreased, but HDL levels increased in all groups (p < .05). These results suggested that the application of dietary NT may present a novel strategy for increasing reproductive performance and health status in L. vannamei.     

Interactive effects of coffee bean supplementation and waterborne zinc toxicity on growth performance,biochemical variables,antioxidant activity and zinc bioaccumulation in whole body of common carp,Cyprinus carpio L.

Roasted coffee powder (RCP; Coffea arabica) is usually used as a beverage for human but there are few attempts to use it as a natural feed supplement in fish diets. In this study, common carp, Cyprinus carpio L., (11.8 ± 0.09 g) were reared in zinc (Zn)‐containing water at concentrations of 0.0 or 5.0 mg/L and cosupplemented with 0.0 or 1.0 g RCP/kg diet for 6 weeks to investigate effects of RCP supplementation, Zn exposure and their interaction on fish performance, biochemical variables, antioxidant activity and Zn bioaccumulation in whole fish body. Fish growth and feed intake were significantly affected by RCP supplementation, Zn toxicity and their interaction. However, fish fed a RCP‐supplemented diet did not exhibit better performance than those fed the RCP‐free diet and both diets produced higher fish performance than the Zn‐toxicated fish. It is noticed that RCP supplementation to Zn‐toxicated fish enhanced their growth, and feed utilization as compared to Zn‐toxicated fish alone. Fish fed control and RCP‐enriched diets showed no significant differences in biochemical variables, which were significantly altered due to waterborne Zn toxicity. Moreover, Zn reduced significantly; meanwhile, RCP supplementation increased significantly superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activities. Notably, Zn exposure could reduce fish growth and antioxidant activity and increase Zn deposition in whole fish body. And RCP intake could enhance the antioxidant activity exerting a protective effect against Zn toxicity, thereby reducing Zn bioaccumulation in whole fish body.     

Fishmeal replacement by soybean,rapeseed and cottonseed meals in hybrid sturgeon Acipenser baerii ♀ × Acipenser schrenckii ♂

A 12‐week feeding trial was conducted to evaluate the effects of replacing fishmeal (FM) with soybean meal (SBM), rapeseed meal (RM) and cottonseed meal (CSM) on growth, feed utilization and body composition of juvenile hybrid sturgeon Acipenser baerii ♀ × Acipenser schrenckii ♂ (initial body weight, 8.63 ± 0.24 g). Five isonitrogenous and isoenergetic diets were formulated as follows: a control diet (FM60) containing 600 g/kg FM and four other diets (FM45, FM30, FM15 and FM0 containing 450, 300, 150 and 0 g/kg FM, respectively) where protein from FM was substituted by a mixture of SBM, RM and CSM. Fish fed FM0 and FM15 had poorer growth performance, feed utilization, apparent digestibility coefficients of dry matter, protein, lipid and gross energy, and fed FM0 had poorer hepatosomatic index and survival compared with the fish fed FM60. The whole body lipid in fish fed FM0 was significantly higher than that in fish fed FM60 and FM15. This study indicates that 300 g/kg of FM can be replaced with a mixture of SBM, RM and CSM in the diet of juvenile hybrid sturgeon without compromising growth performance, feed utilization and body composition.     

Overall development of a bioprocess for the outdoor production of Nannochloropsis gaditana for aquaculture

In this paper, a systematic methodology is shown for the scaling‐up of Nannochloropsis gaditana production for aquaculture uses. First, an adequate culture medium was developed, prepared using fertilizers instead of pure chemicals. Subsequently, the performance of N. gaditana was modelled as a function of average irradiance; this model being validated in continuous culture experiments. The model was used to determine the optimal dilution rate as well as the expected biomass concentration and productivity at optimal conditions. Finally, outdoor experiments were performed to confirm the model's validity and to determine optimal conditions at real production step. Biomass productivity values of up to 0.08 g L^?1 day^?1 were obtained at an optimal dilution rate of 0.25 per day in 0.2 m wide flat‐panel reactors using culture medium containing 0.4 g/L NO^?₃ and 0.034 g/L·PO₄^?3. Fish trials with Atlantic Salmon demonstrated that the inclusion of produced biomass into fed increase the final weight up to 5%, thus confirming the adequacy of the biomass produced for aquaculture uses. The growth model and the scaling‐up strategy proposed here are necessary to develop real industrial‐scale processes capable of supplying microalgal biomass to the aquaculture markets, which in turn require a guaranteed supply and quality of the raw materials provided.     

Effects of rhythmic temperature change on the growth,body composition and energy budget of hybrid grouper (Epinephelus lanceolatus♂ × Epinephelus fuscoguttatus♀)

Effects of rhythmic temperature change on the growth, body composition and energy budget of hybrid grouper (Epinephelus lanceolatus ♂ × E. fuscoguttatus ♀) were investigated. Nine groups of fish received repeating cycles of low‐temperature manipulation (22°C) for 1, 2 and 4 days followed by recovery temperature (28°C) for (3, 7 and 11 days), (6, 14 and 22 days) and (12, 28 and 44 days) respectively, designated as L1R3, L1R7, L1R11, L2R6, L2R14, L2R22, L4R12, L4R28 and L4R44 respectively. In the control group (C), fish were reared at 28°C throughout the whole experiment. After 96‐day feeding trail, the final weight, relative weight gain rate, specific growth rate, food conversion efficiency and apparent digestibility coefficient of fish in L4R28 were significantly higher than those of control (p < .05). The crude protein contents of fish in L2R14, L2R22, L4R12, L4R28 and L4R44 were significantly higher compared to the control (p < .05). According to energy budget, fish in L4R28 exhibited significantly higher proportion of food energy assimilated into growth and lower proportion consumed for excretion than the control fish (p < .05). These results indicated the occurrence of complete or over growth compensation in hybrid grouper, and the use of repeated cycles of low temperature (22°C) for 4 days followed by recovery temperature (28°C) for 28 days could obtain enhanced growth, that is overcompensation, with improved apparent digestibility coefficient, food conversion efficiency and energetic efficiency into growth. This technique would be more practically applicable in indoor culture for this species.     

超低温对降香种子遗传变异和生理特性的影响

采用单因素随机区组试验方案探究降香种子玻璃化超低温保存最适条件,结合显微切片观察和生理生化特性检测对冷冻后细胞形态和生理生化指标变化进行分析,同时运用形态观察法和相关序列扩增多态性（SRAP）分子标记法对超低温保存后的降香植株遗传稳定性进行检测。结果表明：降香种子玻璃化超低温保存最佳条件为：室温（25 ℃）装载 25 min,0 ℃ 玻璃化脱水 30 min,40 ℃水浴解冻 5 min。对比检测不同冷冻时间的降香种子超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、α-淀粉酶、脱氢酶活性、丙二醛（MDA）含量以及电导率等生理生化指标,无明显差异。显微观察超低温保存前后的降香种胚内部结构,未见明显变化。超低温保存后的降香种子发芽时,出现短暂的生长停滞期,恢复培养后,其表观形态指标与对照植株无明显差异。SRAP技术分析了超低温冷冻前后的降香再生植株,其 SRAP 带型基本一致,未见明显差异带型。综上表明,超低温保存降香种子是长期稳定、安全可靠的。     

陕西菜田2种粉虱数量结构及烟粉虱生物型鉴定

旨在研究陕西菜田烟粉虱和白粉虱的数量结构,为粉虱风险评估和防治策略制定提供理论依据。利用定点调查与普查相结合的方法,对陕西关中、陕南和陕北不同生态区、不同季节、不同蔬菜作物以及不同菜田烟粉虱和温室白粉虱的种群分布和组成进行研究,并结合mtDNA-CO1标记基因实现对陕西菜田烟粉虱的生物型鉴定。结果表明,烟粉虱和温室白粉虱的分布和种群组成因地区、季节、作物种植模式不同而异。其中烟粉虱均呈现优势分布,并占到种群数量的67.2%～100%。采用标记基因技术、序列同源性分析和系统发育研究,明确了陕西菜田烟粉虱生物型为Q型烟粉虱。     

植物角质层结构组成、生物学功能及分离方法研究进展

角质层包括角质和蜡质,是覆盖在花、叶和非木质茎等植物地上部分器官的一层疏水性脂类物质,具有限制植物体内水分过度散失、抵御紫外辐射、防止病虫害入侵等功能,在植物生长发育和适应生物与非生物逆境过程中起到重要保护作用。角质层结构以及化学组成是影响其生物学功能的主要原因,具有十分重要的研究价值。综述了植物角质层的结构组成、生物学功能及其常用分离方法,并对已有研究中存在的问题进行了探讨,以期为今后角质层生理作用及其生物学功能方面研究提供理论参考。     

羽毛肽粉对瓦氏黄颡鱼稚鱼生长、体成分和消化酶活性的影响

为研究羽毛肽粉替代鱼粉对瓦氏黄颡鱼Pelteobagrus vachelli幼鱼生长、体成分和消化酶活力的影响,以基础饲料为对照,分别在基础饲料中添加5%、10%、15%、20%羽毛肽粉,饲喂初始体重(25±2)g试验鱼60d。结果表明,试验黄颡鱼增重率、特定生长率随羽毛肽粉添加水平升高呈先升后降趋势,添加水平为10%时,增重率达到最大值117.48%。当添加水平为15%、20%时,增重率、特定生长率显著下降(P0.05);摄食总量随着羽毛肽粉的添加水平也呈先升后降趋势,在10%时,摄食总量达到最大值。饲料系数随着羽毛肽粉添加水平增加呈升高趋势,5%添加组与对照组无显著性差异(P0.05),其余各组均显著高于对照组(P0.05);羽毛肽粉在20%添加水平内对瓦氏黄颡鱼幼鱼体蛋白质、灰分、脂肪、水分无显著性影响(P0.05);试验黄颡鱼肝胰腺胰蛋白酶活力随羽毛肽粉添加水平的升高呈升高趋势,5%添加水平组与对照组无显著差异(P0.05),但显著低于其余各组(P0.05);试验黄颡鱼肠胰蛋白酶活力与肝胰腺蛋白酶活力呈相似的变化趋势,当添加水平达15%时,肠胰蛋白酶活力与胰胰蛋白酶活力比值显著下降(P0.05);不同添加水平羽毛肽粉对试验黄颡鱼淀粉酶活性无显著性影响(P0.05);5%羽毛肽粉添加组的肠、肝胰腺脂肪酶活力最低,显著低于其他羽毛肽粉添加组与对照组(P0.05);羽毛肽粉添加水平至10%时,肠脂肪酶活力与对照组无显著性差异(P0.05),至15%时,肝胰脏脂肪酶活力与对照组无显著差异(P0.05);羽毛肽粉添加组瓦氏黄颡鱼肠胃蛋白酶活性显著高于对照组(P0.05),15%、20%添加组5%、10%添加组对照组,各组间肝胰腺胃蛋白酶活性无显著性差异。在瓦氏黄颡鱼饲料中可以适量添加羽毛肽粉,添加水平在10%以内时,可以显著提高瓦氏黄颡鱼摄食量,促进其生长。     

两种低聚糖对烟草种子萌发及幼苗生长的影响

为研究低聚糖对烟草种子萌发、早期幼苗生长及生理生化指标的影响,通过不同浓度浸种,记录种子萌发情况,30 d后观察早期幼苗形态特征,并分别测定了幼苗叶片的叶绿素、MDA、可溶性蛋白含量、脯氨酸含量、细胞膜透性和SOD、POD、CAT等保护酶活性等生理生化指标。结果表明,两种低聚糖处理对烟草的萌发都有一定的抑制作用,但在其生长期可以补充营养,促进幼苗生长发育。