饲料中碳水化合物水平对鲈鱼生长、生理状态参数及体组成的影响

以初始体重(34.26±0.37)g的鲈鱼Lateolabrax japonicus为研究对象,进行为期70d的生长实验,探讨饲料中不同的碳水化合物(CHO)水平对其生长、饲料利用、血糖水平和糖酵解酶活力的影响。实验配制6种不同CHO水平(0、6%、12%、18%、24%和30%)的等氮等脂饲料。结果表明,随着饲料中CHO水平的升高,特定生长率(SGR)和饲料效率(FE)均呈现先上升后下降的趋势,都在12%组达到最大值,并显著高于24%和30%组(P0.05),而肝体比(HSI)和脏体比(VSI)呈显著升高的趋势(P0.05),且在30%组达到最大值。饲料中不同CHO水平对鲈鱼成活率、肥满度、肌糖原和己糖激酶(HK)活力均无显著影响(P0.05)。饲料中不同CHO水平显著提高了鲈鱼粗蛋白和粗脂肪含量(P0.05),降低了灰分含量(P0.05)。饲料干物质的表观消化率(ADC)在各组之间差异显著(P0.05),18%组显著高于其余5组(P0.05),12%组饲料蛋白质的ADC显著高于对照组(P0.05)。血清中葡萄糖、甘油三酯、胆固醇含量随着饲料中CHO水平的增加而逐渐上升(P0.05),肝糖原含量先显著升高后趋于平稳(P0.05)。以SGR为评价指标,用二次曲线模型分析得出鲈鱼饲料中CHO的适宜添加量为17.75%。     

鲤改良品系与体质量、体长性状相关的TRAP标记筛选

应用TRAP标记对一个鲤(Cyprinus carpio)改良品系72个个体进行扩增,采用其中25个多态性较好引物组合用于该群体遗传多样性分析.运用卡方检验分析25对引物在体质量差异显著的2组鱼中频率差异显著的位点,初步筛选出与体质量和体长性状相关的TRAP标记.将初步筛选的TRAP标记用于随机群体132个个体进行位点性状间的关联分析.结果表明,25个TRAP分子标记共扩增出353个位点,其中多态性位点230个,平均多态性比率65％,平均多态性信息含量为0.28,Nei's遗传多样性指数平均值为0.219,Shannon信息指数平均值为0.329,表明该群体遗传多样性较为丰富.在初步筛选出的3个TRAP位点(ghlTrap04-140、4rTrap04-308、igf4Ga5-135)中,4rTrap04-308与体质量、体长呈极显著相关(P<0.01).本研究利用TRA这一新型分子标记对1个鲤改良群体进行遗传分析,并寻找出1个可能与鲤体质量,体长性状相关的功能基因位点,旨在为鲤体质量、体长性状的QTL定位和分子标记辅助育种奠定基础.     

北京地区冬小麦品种冠层结构的研究

1983～85年对本地区22个冬小麦品种的产量及其构成因素与上部三个节的茎、叶和穗部性状的关系进行了研究。结果表明,在产量水平为5～6吨/公顷时,决定产量的主导因素是穗粒重,其中千粒重和穗粒数的贡献大体相同。上部三个叶片性状有较大的一致性,旗叶宽、面积、绿色面积持续期对穗粒数、粒重、穗粒重有中度正相关,其中叶宽影响较大;但与穗数/米~2呈中度负相关,因而与产量表现为一定程度的正相关。茎、鞘直径与产量构成因素关系比长度密切,上部茎节直径影响也比下部大。逐步回归分析表明决定产量的还是产量构成因素本身,旗叶性状居从属地位,其中开张角、基角和叶宽对千粒重的影响较大。将产量居前五名品种的主要性状平均值与由曲线回归方程计算而得的“最优值”相比较,二者基本一致。据此提出选育产量潜力为6吨/公顷上下品种时可加考虑的冠层性状指标。     

水体强反光环境中无人机多光谱影像的辐射一致性校正

为了提高水体强反光干扰的遥感影像信息提取准确度,该研究以柑橘树冠营养元素水平检测而采集的无人机多光谱影像为对象,对水体强反光造成的相同地物在不同影像上辐射信息不一致现象进行校正,从而提高营养元素水平检测的精度.首先对影像进行暗角校正,然后利用直方图对比度拉伸辅助SIFT(Scale invariant feature ...     

血清Ⅰ型鸭源副粘病毒HN蛋白基因的遗传变异及原核表达

参考GenBank发表的鹅副粘病毒（GPMV）SF02株基因组核苷酸序列，设计并合成了1对特异性引物，采用RT—PCR技术扩增鸭源血清I型禽副粘病毒DP1／0z株的HN基因，并进行遗传变异及原核表达研究。结果显示，HN基因共1716bp，编码571个氨基酸，存在6个潜在的糖基化位点和13个完全保守的半胱氨酸（C）残基。与GenBank中收录的鹕源副粘病毒HN基因核苷酸和氨基酸的同源性分别为81．3％～98．3％和87．2％～98．4％，系统进化树分析表明DP／02株与鹅源副粘病毒处于同一进化分支。经SDS—PAGE、Western—blot分析，原核表达的HN蛋白相对分子质量在63000左右，1mol／L（终浓度）IPTG时间梯度诱导，3h时HN蛋白表达量最高，占整个菌体蛋白含量的30％，且能与鼠抗鸭源血清I型禽副粘病毒阳性血清反应。     

毒害艾美耳球虫氧化还原酶EnOXIO1的原核表达与定位分析

旨在探析毒害艾美耳球虫氧化还原酶EnOXIO1的功能。提取毒害艾美耳球虫扬州株配子体总RNA,应用RT-PCR获取EnOXIO1编码基因,构建原核表达载体pET-28a(+)-EnOXIO1,转化至大肠杆菌BL21(DE3),体外诱导表达,对重组蛋白进行抗原性分析,应用制备的多抗进行激光共聚焦免疫荧光定位。结果显示,获得的EnOXIO1基因全长为2 535 bp,体外重组表达的蛋白大小约100 ku,主要以包涵体的形式存在,表达量约为0.5 mg·mL^-1。Western blot分析结果显示,该重组蛋白能被6×HIS标签单克隆抗体识别,同时能被制备的鼠多抗以及毒害艾美耳球虫、堆型艾美耳球虫和柔嫩艾美耳球虫病鸡康复血清所识别,表明该重组蛋白具有较好的反应原性和交叉反应原性。激光共聚焦免疫荧光定位结果显示,EnOXIO1基因表达产物主要存在于配子体内的成壁体上,参与了卵囊壁的形成。本研究成功克隆和表达了毒害艾美耳球虫EnOXIO1蛋白,并将其定位于配子体和卵囊壁上,为进一步解析EnOXIO1蛋白参与卵囊壁形成的分子机制奠定基础,为研制新型免疫阻断型球虫亚单位疫苗提供重要靶抗原。     

通用引物扩增甲型流感病毒基因组及其高通量测序

为探索使用高通量测序方法测定甲型流感病毒的基因组,设计了一对通用引物进行甲型流感病毒全基因组的RT-PCR扩增,并分析了该方法的敏感性。结果显示,该方法能够扩增的甲型流感病毒多种亚型的全部8个节段的基因,其扩增敏感性为100 pg RNA。     

IL‐12p40 gene expression in lung and hilar lymph nodes of MPS‐resistant pigs

Mycoplasma pneumonia of swine (MPS) is caused by Mycoplasma hyopneumoniae (M.hp) and is a common chronic respiratory disease of pigs. Recently, a genetically selected variant of the Landrace pig (Miyagino L2) has a lower incidence of pulmonary MPS lesions. We investigated the pathological and immunological characteristics of MPS resistance in these pigs (n = 24) by comparing with the normal landrace pig (control: n = 24). The pathological MPS lung lesion score in MPS‐selected landrace pigs was significantly lower than in the control. The gene expression of interleukin (IL)‐12p40, which acts as a chemoattractant and a component of the bioactive cytokines IL‐12 and IL‐23, was significantly higher at the hilar lymph nodes, lung, and spleen in MPS‐selected landrace pigs than in control landrace pigs, and these were negatively correlated with the macroscopic MPS lung lesion score. In summary, we demonstrate that resistance against MPS in Miyagino L2 pigs is associated with IL‐12p40 up‐regulation, in comparison with normal landrace pigs without the MPS vaccine. In addition, a comparative study of macroscopic MPS lung lesions and IL‐12p40 gene expression in lung and hilar lymph nodes may lead to beneficial selection traits for the genetic selection for MPS resistance in pigs.     

Effect of cationic structure of ionic liquids on dissolution and regeneration of white hide powder

3-methyl-1-ethoxycarbonylimidazolium chloride ([EtMIM]Cl), was synthesized for white hide powder dissolution. White hide powder was successfully dissolved in [EtMIM]Cl, and regenerated from methanol. The dissolution data and thermodynamic parameter of white hide powder in [EtMIM]Cl and [BMIM]Cl were studied. Hydrogen bond basicity (β) and general polarizability (π*) of ILs were determined. The white hide powders were characterized by FT-IR, XRD, and TGA. The results showed that the maximum solubility of white hide powder in [EtMIM]Cl was higher than that in [BMIM]Cl at same dissolution temperature. At same temperature and same solid content, the dissolution time of white hide powder in [EtMIM]Cl was shorter than that in [BMIM]Cl. Density functional theory (DFT) simulation showed that two kinds of hydrogen bonds (C-H/O and C-H/Cl) and eight strong hydrogen bonds are found in [EtMIM]Cl/GPH, while seven hydrogen bonds are found in [BMIM]Cl/GPH. The carboxylic acid ester cationic group in [EtMIM]⁺ has more electronegative ester groups and stronger electronic cloud density oxygen atoms than alkyl group in [BMIM]⁺, [EtMIM]Cl is easier to destroy the intermolecular or intramolecular hydrogen bonds in white hide powder, so as to accelerate the dissolution of white hide powder in [EtMIM]Cl. The molecular simulation results indicated that both Cl^? anions and [EtMIM]⁺ cation played important roles in the white hide powder dissolution.     

Marker‐assisted selection for rice blast resistance genes Pi2 and Pi9 through high‐resolution melting of a gene‐targeted amplicon

The use of host resistance (R) genes is considered the most cost‐effective option to control the rice blast disease. The two allelic R genes Pi2 and Pi9 confer very broad‐spectrum resistance against blast isolates collected worldwide. However, the two genes have not yet been widely deployed in rice breeding programmes. Availability of specific markers for them would facilitate incorporating the two R genes into new rice lines through marker‐assisted selection. Herein, we report the development and utilization of a robust and specific marker for the Pi2 and Pi9. This marker was derived from polymorphisms within the target gene, and achieved simultaneously distinguish Pi2 and Pi9 from other alleles through high‐resolution melting of a small amplicon. With the marker, we were able to transfer the Pi2 into an elite restorer line through marker‐assisted backcrossing, successfully obtained effective resistance to blast disease, and we were also able to, respectively, incorporate the Pi2 and Pi9 with two other R genes. As the additive effect, blast resistance in these stacking lines harbouring three R genes were significantly improved.