摄食不同饲料幼鲤肝胰脏和肠道蛋白酶活性的研究

采用膨化加工的家禽下脚粉替代不同比例鱼粉配制四组试验饲料，分别饲喂同批孵育的幼鲤（平均体长5．45±0．78cm，体重1．38±0．21g）76天，水温22～25℃，日投喂量占鱼体重5％。实验结束时各组受试鱼肝胰脏、肠道蛋白酶活性和生长测定结果表明：不同试验饲料对幼鲤肝胰脏、肠道蛋白酶活性有一定影响；添加家禽下脚粉各组明显高于鱼粉（对照）组P＜0．05）；幼鲤生长和蛋白质效率与蛋白酶活性显示正相关。     

东海区夏、秋季大型水母分布区渔业资源特征分析

本文根据1999～2004年的夏季和秋季东海区大型水母和渔业资源的状况,分析了大型水母分布区内的渔业资源特征。结果表明大型水母夏季主要分布于30°30′～33°00′N间,秋季主要分布于32°00′N以北海域,并呈现由夏季到秋季逐渐往北转移的趋势;2003年是大型水母数量最高的年份,该年水母主要分布区内的渔业资源种类数最少,CPUE最低,Margalef种类丰富度指数也最低;2003年夏季水母高发区内渔获种类的优势度也较其它年份发生了显著变化,优势种变为黄;2003年水母高发区内带鱼、小黄鱼和银鲳的当龄鱼较少,银鲳的肥满度增加,小黄鱼的肥满度降低,而带鱼的肥满度未发生显著变化。本文对水母高发区内渔业资源变化的原因进行了初步解释,并对水母的防治措施提出了初步的建议。     

Chicory （Cichorium intybus L.） and cereals differently affect gut development in broiler chickens and young pigs

Dietary fiber, resistant to host-mediated digestion in the small intestine due to lack of endogenous enzymes, impacts many facets of animal health and is associated with gut development especially in young monogastrics. Furthermore, it can be used as in-feed antibiotic alternative. Chicory （Cichorium intybus L.） forage with high content of pectin （uronic acids as building blocks） is a novel class of dietary fiber that is chemically different from cereal grains （with high content of arabinoxylans）. In the present study, we investigated effects of dietary inclusion of chicory forage on digestibility, gut morphology and microbiota in broilers and young pigs. In the chicken experiment, 160 1-d old broiler chicks were fed 3 nutritionally balanced diets for 30 d including a cereal-based diet and 2 diets with part of the cereals substituted with 60 and 120 g/k9 chicory forage （CF60 and CF120], whereas in the pig experiment, 18 seven-wk old Yorkshire pigs were fed 3 diets for 18 d including a cereal-based diet and 2 diets with 80 and 160 g/kg chicory forage inclusion （CF80 and CF160）. Our results showed that young pigs were capable to utilize chicory forage well with higher total tract apparent digestibility （TTAD） of all fiber fractions, particularly uronic acid, compared with the control （P 〈 0.01）. In contrast, a decreased TTAD of all fiber fractions was observed in chickens fed on diet CF120 （P 〈 0.05）. Moreover, diet induced changes in gut morphology were observed in the large intestine of chickens. The alteration of cecal mucosal thickness was further positively correlated with TTAD of non-starch polysaccharides （NSP） and its constituent sugars （P 〈 0.05）. In addition, in pigs, terminal restriction fragment length polymorphism （T-RFLP） analysis of intestinal microbiota revealed substantial dietary effects （cereal control diet vs. chicory forage inclusion） on the relative abundance of 2 dominant bacterial phylotypes （Prevotella sp. vs. Roseburia sp.） respective     

利用液相氧电极技术研究“海天1号”海带(Saccharina japonica)幼孢子体光合及呼吸速率

“海天1号”海带是南方耐高温品种与北方高产品种杂交后,经过几代选育获得的海带新品系,具有产量高、耐高温、成熟稍早等特点(暂命名为“海天l号”海带).为探究“海天1号”海带幼孢子体在不同环境因子下的生理适应性,设置了温度、光强及营养盐3个单因素实验,利用液相氧电极技术研究其对“海天l号”海带幼孢子体(1-2 cm)表观光合速率(Pn)和呼吸耗氧速率(R)的影响,并测定相对生长速率(Relative growth rate,RGR).结果显示:(1)温度为14℃、光强为80 μmolphotons/(m2.s)、氮营养盐为6 mg/L(N/P=10∶1,下同)环境下,幼孢子体的RGR和Pn均较大.在温度为22℃、光强为1 00 μmol photons/(m2·s)、氮营养盐浓度为10 mg/L条件下,R最强.(2) 22℃组的幼孢子体生长受到抑制,其RGR显著低于14℃组(P＜0.05).20 μmol photons/(m2·s)与80 μmolphotons/(m2·s)光强组的RGR存在显著性差异(P＜0.05).单因素方差分析显示,5个营养盐浓度组之间幼孢子体的RGR无显著性差异(P＞0.05).(3)随着温度、光强、营养盐浓度增加,幼孢子体的Pn呈先上升后下降的趋势,14℃组Pn显著高于其他温度组,氮营养盐浓度4 mg/L和6 mg/L组的Pn显著高于2、8和10 mg/L组(P＜0.05).在本实验条件下,R和Pn呈负相关.(4)光强对幼孢子体P/R(总光合速率/呼吸耗氧速率)的影响较小,温度和营养盐浓度对其影响较大.正交实验结果显示,适宜“海天1号”海带幼孢子体培养的条件为光强50 μmol photons/(m2·s)、温度16℃、氮营养盐浓度5 mg/L.     

海蜇生长、存活影响因子的研究现状

海蜇是经济价值很高的食用水母,是我国沿岸养殖和捕捞的重要对象。本文不仅综述了溶氧、温度、盐度、光照、营养条件、重金属离子、pH、氨氮、气候和水文状况等自然因子对海蜇不同生长阶段的影响,而且从养殖用水管理、机械损伤和敌害生物等方面对海蜇生活史中各个时期生长、存活的影响做了概述。总结发现,各种因子对海蜇的生长、发育、存活都有明显的影响,但其作用机理和我们对其的调控方法仍有待进一步研究。在海蜇研究,乃至钵水母纲动物的生理学、生态学研究中仍有大量的工作要做。     

龙海市菜用大豆田甜菜夜蛾发生特点及防控策略

通过系统调查和历史资料整理,对龙海市甜菜夜蛾的发生特点进行了研究总结,提出了以农业防治和预测预报为基础,高效环保的物理和生物防治为助力,有效的药剂防治为主的甜菜夜蛾综合防控策略。     

不同品种苹果幼果期冻害比较及补救措施

以豫西地区果园5个不同苹果品种幼果为材料,比较果实的受冻情况。结果表明,不同品种间幼果的受冻程度存在明显差异,‘金冠’和‘瑞雪’受冻程度较轻,分别为37.5%和38.5%,‘嘎拉’受冻率次之,为61.0%,而‘富士’和‘红星’的受冻比例最大,达到78.0%和77.5%。同时,提出相关冻害补救措施,为苹果冻害防治提供技术参考。     

Lipid Peroxidation Is another Potential Mechanism besides Pore-Formation Underlying Hemolysis of Tentacle Extract from the Jellyfish Cyanea capillata

This study was performed to explore other potential mechanisms underlying hemolysis in addition to pore-formation of tentacle extract (TE) from the jellyfish Cyanea capillata. A dose-dependent increase of hemolysis was observed in rat erythrocyte suspensions and the hemolytic activity of TE was enhanced in the presence of Ca²⁺, which was attenuated by Ca²⁺ channel blockers (Diltiazem, Verapamil and Nifedipine). Direct intracellular Ca²⁺ increase was observed after TE treatment by confocal laser scanning microscopy, and the Ca²⁺ increase could be depressed by Diltiazem. The osmotic protectant polyethylenglycol (PEG) significantly blocked hemolysis with a molecular mass exceeding 4000 Da. These results support a pore-forming mechanism of TE in the erythrocyte membrane, which is consistent with previous studies by us and other groups. The concentration of malondialdehyde (MDA), an important marker of lipid peroxidation, increased dose-dependently in rat erythrocytes after TE treatment, while in vitro hemolysis of TE was inhibited by the antioxidants ascorbic acid—Vitamin C (Vc)—and reduced glutathione (GSH). Furthermore, in vivo hemolysis and electrolyte change after TE administration could be partly recovered by Vc. These results indicate that lipid peroxidation is another potential mechanism besides pore-formation underlying the hemolysis of TE, and both Ca²⁺ channel blockers and antioxidants could be useful candidates against the hemolytic activity of jellyfish venoms.     

连续施肥对杉木幼林生物量的影响

[目的]研究连续施肥对杉木幼林生物量的影响,为杉木人工林合理施肥和可持续经营提供基础资料.[方法]通过对1～5年生杉木幼林进行连续施肥,调查研究杉木幼林生长情况,以及施肥对杉木幼林生物量的影响.[结果]连续施肥对杉木幼林生物量的影响显著.随着林龄的增加,施肥处理和不施肥处理的杉木单株各组分生物量不断增加.其中树干生物量增加得更快.施肥处理第5年,杉木各组分的生物量所占比重分别为树叶13％、树枝25％、树皮9％、树干32％和树根18％.[结论]各组分生物量变化幅度由大到小依次为树干、树枝、树根、树叶、树皮.     

秸秆覆盖对低龄茶园土壤性状和地表养分流失的影响

研究了在1年龄茶园中秸秆覆盖对低龄茶园土壤性状和地表养分流失的影响,结果表明:低龄茶园行间覆盖农作物秸秆可以显著提高表土活性有机质含量、土壤微生物数量和酶活性、土壤速效磷、速效钾含量,以及水稳定性团聚体含量,降低表层的土壤容重,进而增强了土壤保水作用。全覆盖处理对促进土壤活性有机碳、微生物活性和速效养分含量的增加,以及提高水稳定性团聚体形成的作用略高于半覆盖处理;但在减少养分流失及地表径流量方面,全覆盖处理与半覆盖处理间无明显的差异。因此,低龄茶园行间覆盖农作物秸秆具明显的生态效应,可有效降低水土流失,改善茶园土壤理化性质,协调茶园土壤养分供应,可以作为南方山区茶园的水保措施。