不同氮源对铜绿微囊藻增殖的影响

在实验室条件下,利用单细胞藻一次性培养方法,研究了硝酸氮、铵氮和尿素对铜绿微囊藻（Microcystis aeruginosa）增殖的影响。结果表明：以硝酸氮作为氮源时,铜绿微囊藻增殖速率优于另外2种氮源条件下的,其最适增殖浓度为1.5～5.0mmol/L。低浓度铵氮（0.5mmol/L）即适宜铜绿微囊藻生长,而高浓度时会抑制铜绿微囊藻生长。尿素氮浓度0.5～1.5mmol/L时最利于铜绿微囊藻生长。试验结果提示在监测水体氮营养盐时应该包括多种无机氮和有机氮,只测总氮难于准确预测水华。     

两种鲤鲫杂交回交子代染色体核型分析及比较

采用PHA和秋水仙素体内注射制备两种鲤鲫杂交回交子代鱼（鲤鲫杂交♀×德国镜鲤♂;鲤鲫杂交♀×鲤♂）的染色体。结果表明：两种鲤鲫杂交回交子代染色体组由150条染色体组成,按着丝粒位置染色体组型可分为四组,每个染色体小组均由三条同源染色体组成。其中鲤鲫杂交♀×鲤♂回交的染色体数目为3n=150,染色体臂数NF=234,其核型公式为：3n=60m＋24sin＋36st＋30t;鲤鲫杂交♀×德国镜鲤♂回交染色体数目为3n=150,染色体臂数NF=258,其核型公式为：3n=63m＋45sin＋12st＋30t。     

A comparison of fatty acid composition and quality aspects of eggs and larvae from cultured and wild broodstock of common sole (Solea solea L.)

Eggs from a F₁ cultured broodstock of sole were compared with eggs from wild‐caught breeders throughout one spawning season, to evaluate if egg quality may be affected by culture‐related conditions. Fourteen batches of eggs from cultured broodstock and 17 batches from wild‐caught sole were compared with respect to fatty acid (FA) composition, egg size, fertilization rate and hatching rate. Based on a multivariate analysis of the FA profiles, it was possible to discriminate between culture and wild inheritance. Eggs from cultured broodstock had high levels of C20:1(n‐9), C18:2(n‐6) and C18:3(n‐3), whereas eggs from wild fish had high levels of C16:1(n‐7), C20:4(n‐6) and C20:5(n‐3). Differences in FA profiles were most likely related to dietary differences. Fertilization and hatching rates were generally low and lowest in eggs from cultured broodstock, but not related to FA composition. Larval growth of one batch from each group was compared. Larval growth was not correlated to broodstock origin, FA composition or egg or larval size. However, larval survival was significantly lower for larvae from cultured broodstock.     

Effects of antimicrobial peptides on growth,morphology of foregut villi and related genes mRNA expression in the common carp (Cyprinus carpio)

A 60‐day feeding trial was conducted to examine the effects of different levels (0, 100, 200, 400 and 600 mg/kg) of antimicrobial peptides on growth, protease activity of foregut, the morphology of foregut villi and related genes mRNA expression level in the common carp (Cyprinus carpio). The results showed that the feed of antimicrobial peptides promote common carp growth, and the optimal dosage of antimicrobial peptides is 200–333 mg/kg in the common carp feed. The protease activity of 200 and 400 mg/kg groups were significantly higher than the control and other groups (p < 0.05). The foregut villus height with 100, 200 and 400 mg/kg antimicrobial peptide groups were significantly higher than control group (p < 0.05). The crypt depth of 200 and 400 mg/kg antimicrobial peptide groups were significantly lower than control group (p < 0.05). The ratio of villus height and crypt depth of 100, 200 and 400 mg/kg antimicrobial peptide groups were significantly higher than control group (p < 0.05). The ratio with 600 mg/kg group was significantly lower than the control group (p < 0.05). The IGF‐I gene expression level of 200 mg/kg and 400 mg/kg groups were significantly higher than the control group and 600 mg/kg group (p < 0.05). The IL‐1β gene expression level of 100 mg/kg and 200 mg/kg groups were significantly higher than the control group (p < 0.05). These results indicated up‐regulation of growth and immune related genes in antimicrobial peptides fed common carp. Correlation analysis showed that IGF‐I mRNA and IL‐1β mRNA were positively correlated with SGR. IL‐1β mRNA and FCR were significantly negative correlated. It indicated that growth and immune gene common regulated the growth of the carp under antimicrobial peptides intervention. In conclusion, antimicrobial peptides can improve growth and related genes mRNA expression in the common carp. Further studies using molecular biological technique or immunologic methods are required to conclude that antimicrobial peptides are beneficial in common carp.     

鲤鱼血淋巴细胞培养及染色体制备条件探索

从鲤鱼侧线鳞处静脉采血于含有肝素的一次性注射器中，采用RPMI1640全培养基进行体外淋巴细胞培养。通过对采血后细胞培养时间、秋水仙素浓度及加入时间、低渗时间及温度等条件的摸索，建立了较成熟的培养鱼类血淋巴细胞的实验方法。     

利用GoldenGate分析的高通量SNP芯片对鲤基因进行分型

单核苷酸多态性(SNPs)标记在大多数物种基因组中数量巨大且分布均匀,是许多水产物种遗传研究的理想标记,因此快速发展了几种高通量、快速的SNP标记分型平台。本研究利用Golden Gate分析技术对鲤Cyprinus carpio转录组测序的1 536个SNP标记合成了一张中等密度SNP芯片,对5个鲤群体的480份样本进行基因分型。结果表明:1 235个SNP标记成功分型,约占80%;915个标记至少在一个家系中呈现多态性,占74.1%;标记最小等位基因频率(MAF)介于0.05~0.5之间,平均为0.334,其中48.9%的标记最小等位基因频率(MAF)大于平均值;5个群体中SNP标记平均多态性信息含量(PIC)在0.3左右,为中度多态,杂合度为0.010~0.990,平均为0.5左右,暗示群体具有丰富的遗传多态性,育种价值及性状改良潜力很大。本研究分型的多态性SNP标记可广泛应用于遗传多样性研究、标记-性状关联分析以及分子标记辅助育种。     

鲤鱼基因组同源框Hoxa3a序列同源性分析与分子进化研究

本文利用生物信息学软件分析了鲤（Cyprinus carpio）基因组中同源框基因Hoxa3a与多种鱼类及其它生物的同源性,构建了分子进化树。结果表明：鲤与斑马鱼（Danio rerio）的序列同源性最高为95%,与大西洋鲑（Salmo salar）等四种鱼类的同源性次之为84%,与米氏叶吻银鲛（Callorhinch...     

三种鲤对暴发性鱼病抗病力的差异

本文报道三种鲤对嗜水气单胞菌引起暴发性鱼病的抗病力试验结果。当菌液浓度为６．０×１０￣８ＣＦＵ／ｍｌ，采用１０￣０、１０￣（－１）、１０￣（－２）、１０￣（－３）四个稀释度、０．３ｍｌ／尾注射剂量时，建鲤、野鲤和镜鲤的半数致死量（ＬＤ＿（５０））分别为１０￣（－１．３７５）、１０￣（－０．９７６）、１０￣（－０．５６２）。这三种鲤的半数致死量差异显著（Ｆ＞Ｆ＿（０．０５））。从四个方面研究了抗病机理：白细胞吞噬功能和补体替代途径（Ｃ＿３旁路）杀菌能力，镜鲤较强于野鲤和建鲤，但无显著差异（Ｆ＜Ｆ０．０５）；红细胞Ｃ＿（３ｂ）受体花环率和补体总量（单位／ｍｌ），是建鲤＞野鲤＞镜鲤，差异极显著（Ｆ＞Ｆ０．０１）。本研究结果还表明建鲤的红细胞Ｃ＿（３ｂ）受体花环率和补体总量稍高，但对暴发性鱼病病原（嗜水气单胞菌）较易感染。以上结果证明，不同品系鲤鱼对暴发性鱼病有种内特异性。     

鲤鱼脱脂方法的研究

分别采用水漂洗、有机溶剂浸提、脂肪酶酶解的方法对鲤鱼鱼肉进行脱脂。试验结果表明,水漂洗法中,清水漂洗效果最优;有机溶剂浸提法中,异丙醇脱脂效果最佳,并对其采用正交试验方案对异丙醇脱脂工艺进行优化,得到最佳试验条件是:脱水时间30 m in,脱脂时间110 m in,温度为75℃,溶剂添加量为50 g;脂肪酶脱脂试验得出最佳条件是加酶量40 U/m l,酶作用时间50 m in。3种方法中,脂肪酶脱脂效果最佳。     

苹果园春季土施尿素的利用及其在土壤中的累积

 以7年生嘎拉苹果/平邑甜茶为试材, 利用¹⁵N示踪技术, 研究了苹果生产体系中氮素年周期 的利用、残留、损失及在土壤中的迁移动态。结果表明, 对春季土施尿素的利用率盛花期较低, 为11.38% , 至采收后达到最高。土壤氮素残留率盛花期最高, 为57.10% , 果实采后残留率最低。年周期中各土层氮素残留量不同, 盛花期20～40 cm土层残留量最高, 采收后最低, 0～20 cm土层在新梢旺长期残留量最高, 果实成熟期最低, 而40～60 cm土层在果实膨大期残留量达到最高, 在采收后0～20 cm土层残留有所增加, 其余各土层残留量均达到最低值。氮素损失与土壤残留呈相反的变化趋势, 氮素损失率在盛花期最低为31.53% , 随物候期的推迟逐渐升高, 在果实采后高达58.40%