氮肥用量对中筋小麦扬麦11号产量和群体质量的影响

为给中筋小麦优质高产氮肥的精量确定提供科学依据,以中筋小麦扬麦11号为材料,研究了氮肥用量对其产量和群体质量的影响。结果表明：在氮肥基追比为5:5、追肥在拔节期施用的条件下,产量与施氮量呈二次曲线关系,以施氮量225~281.25kg/hm2处理的产量、茎蘖成穗率、最大叶面积指数和成熟期干物质积累量较高。     

大豆不同生育时期叶绿素含量QTL的定位及其与产量的关联分析

利用来自波高×南农94-156的151个RI家系检测与4个不同生育时期叶绿素含量（累积量、净增量）有关的QTL,并分析其与籽粒产量、表观生物学产量和表观收获指数的关系。结果表明,与叶绿素累积量有关的QTL位于D1a+Q、F、G、H、L和M连锁群上,每个QTL可解释表型变异的6.9%~23.4%。V6和R2期没有检测到2个年份均表达的QTL,而在R4期检测到4个在2个年份均表达的QTL（qccF.1、qccG.2、qccH.1和qccM.1）,R6期仅检测到1个QTL（qccH.1）在2个年份均表达,该QTL在R4也表达。与叶绿素含量净增量有关的QTL位于B2和L连锁群上,在V6-R2时期没有检测到与叶绿素净增量有关的QTL,在B2和L连锁群上的两个QTL（qccB2-1.1和qccL.1）在R2-R4和R4-R6时期均表达,qccB2-1.1可解释表型变异的6.4%~9.8%,而qccL.1所解释表型变异达29.5%~31.3%。但这两个QTL在R2-R4和R4-R6时期表达的性质不同,且与2年均表达的籽粒产量QTL共位。这印证了生育后期叶绿素含量与籽粒产量间存在的极显著正相关。     

siRNA沉默NCOA2基因对猪肌内前体脂肪细胞分化的影响

[目的]本文旨在研究核受体共激活蛋白2(nuclear receptor coactivator 2,NCOA2)对猪肌内前体脂肪细胞分化能力的影响。[方法]用荧光定量PCR(qRT-PCR)法检测NCOA2在猪肌内前体脂肪细胞分化过程中的表达变化;通过NCOA2小干扰RNA(small interfering RNA,siRNA)抑制内源NCOA2的表达,并用油红O染色检测沉默NCOA2对肌内前体脂肪细胞分化能力的影响,通过qRT-PCR检测沉默NCOA2对脂肪分化关键基因过氧化物酶体增殖物激活受体γ(peroxisome proliferator activated receptorγ,PPARγ)、脂肪酸结合蛋白4(fatty acid binding protein 4,FABP4)、脂蛋白酯酶(lipoprotein lipase,LPL)和脂联素(adiponectin,ADIPOQ)表达的影响。[结果]NCOA2在肌内前体脂肪细胞分化第4天表达量显著升高(P0.05);降低NCOA2表达可显著抑制肌内前体脂肪细胞分化(P0.05),且PPARγ、FABP4、LPL和ADIPOQ基因的表达也受到显著抑制(P0.05)。[结论]体外siRNA沉默NCOA2基因可抑制猪肌内前体脂肪的分化,这可能与PPARγ、FABP4、LPL、ADIPOQ等基因的低表达有关。     

2007-2010年江苏地区猪繁殖与呼吸综合征病毒RT-PCR检测及部分Nsp2基因序列分析

本研究参考GenBank已发表的猪繁殖与呼吸综合征病毒（Porcine reproductive and respiratory syndrome virus,PRRSV）Nsp2基因序列,在高致病性病毒Nsp2基因缺失区的两端保守区设计并合成了一对引物,建立并优化了能够区分经典PRRSV和高致病性PRRSV的RT-PCR诊断方法,并利用该方法对2007～2010年间江苏地区的45份可疑临床病料进行了检测。结果表明临床病料阳性率为40％,所有毒株均属于高致病性毒株。对PRRSV阳性病毒的Nsp2基因序列分析表明,所有18株PRRSV均属于美洲型毒株,与中国高致病性PRRSV代表毒株JXA1、WUH1的氨基酸同源性分别在82．2％～97．6％、80．4％～95.3％。此外,18株病毒的Nsp2共同存在不连续的30个氨基酸缺失,缺失位置与同期中国高致病性PRRSV具有相同的特征。通过本研究掌握了江苏地区2007～2010年间PRRSV流行情况及Nsp2基因变异特征,为地方猪繁殖与呼吸综合征的临床诊断和防治提供参考依据。     

三种抗球虫药物对家兔CYP1A2 mRNA和蛋白表达的影响

利用Real-time PCR和Western blot分别检测抗球虫药物磺胺喹噁啉、氯苯胍和妥曲珠利对家兔肝脏、肾脏、十二指肠中CYP1A2mRNA和蛋白表达的影响。40只新西兰白兔分为空白对照组、磺胺喹噁啉处理组、氯苯胍处理组和妥曲珠利处理组。空白对照组家兔饲喂正常颗粒饲料,磺胺喹噁啉处理组饲喂含25mg/kg浓度磺胺喹噁啉的颗粒饲料,氯苯胍处理组饲喂含66mg/kg浓度氯苯胍的颗粒饲料,妥曲珠利处理组饲喂含2mg/kg浓度妥曲珠利的颗粒饲料,连续30d。在第31天无菌条件下取出动物的部分肝脏、肾脏以及十二指肠,提取RNA、蛋白分别进行Real-time PCR、Western blot检测。Real-time PCR的结果表明,磺胺喹噁啉、氯苯胍和妥曲珠利都能够诱导家兔肝脏和肾脏CYP1A2mRNA的表达,而妥曲珠利能够显著的抑制十二指肠CYP1A2mRNA的表达。Western blot结果表明,磺胺喹噁啉、氯苯胍和妥曲珠利能够显著的诱导家兔肝脏CYP1A2蛋白水平的表达;磺胺喹噁啉显著的诱导肾脏和十二指肠CYP1A2蛋白表达,而氯苯胍能够显著的抑制肾脏CYP1A2蛋白的表达。结果提示,磺胺喹噁啉、氯苯胍和妥曲珠利对家兔CYP1A2mRNA和蛋白水平的表达均具有组织特异性,在不同的组织器官呈现出显著的诱导和抑制作用。     

Quantifying the Dynamics of Livestock Distribution by Unmanned Aerial Vehicles (UAVs): A Case Study of Yak Grazing at the Household Scale

Managed grazing is the most extensive land use worldwide. Information about the spatio-temporal distribution of livestock is critical for grassland ecosystem management. However, no direct and cost-effective method exists to monitor livestock distribution under natural conditions. We proposed a practical method that uses unmanned aerial vehicles (UAVs), and tested it at a typical household pasture on the Qinghai-Tibetan Plateau. We monitored and analyzed the hourly spatial distribution of each yak (Bos mutus). We found that (1) yak information extracted by our independently developed software was sufficiently accurate (P > 0.05); (2) yak density (frequency/area/period) decreased with increasing distance from campsites in the early growing season, while the pattern reversed in the late growing season; (3) dispersion index (DI, m²/yak) of the yak herd exhibited a tendency to decrease in the morning and then to increase in the afternoon within a day; from June to September DI decreased in both the morning and afternoon, but was similar at noon. The monitoring method we developed in this study characterized the spatial distribution of the whole yak herd dynamically with high frequency, resolution, and efficiency. We conclude that this method is suitable for long-term monitoring of animal behavior, and for studying relationship between the distribution of pastoral livestock and resource availability, which will be beneficial for grassland sustainable management.     

Risk factors of Salmonella infection in laying hens in Menoua Division,Western region of Cameroon (Central Africa)

Salmonella infections in poultry farms are overlooked in many African countries; yet these infections are mostly zoonotic with impact on both poultry industry and public health. Considering the impact of Salmonella in laying hens, and the role of laying hens as a source of Salmonella outbreak in human, knowledge of the status of Salmonella on laying hen farms as well as the factors influencing the presence of Salmonella is important. In a cross sectional study, cloacal swabs were collected from 270 commercial laying hens on 27 farms located in Menoua Division. These samples were cultured on standard media. A questionnaire was used to collect information on animals, farms and farmer’s characteristics. The prevalence of Salmonella was 93.34%; three zoonotic isolates namely S. Enteritidis (75.90%), S. Paratyphi (11.90%), and S. Typhimurium (5.60%) were identified. The location of farms was significantly associated with presence of Salmonella, and the risk of infection was 10-fold higher in Nkong-ni than Santchou (p < 0.05). Other potential risk factors such as flock size, age of the farm (infrastructure), or water source were not associated with Salmonella infection. The prophylactic measures against avian diseases in the country must include measures against Salmonella to protect poultry industry and public health.     

一种滩涂两栖车辆稳性的分析

运用两栖车辆相关理论,对一种半潜作业的滩涂车辆在沿海滩涂作业中的稳性进行了计算。验证总体设计中总体布置的合理性和正确性,并给出不同水深下稳性对车辆作业稳定性的影响,为优化设计提供参考和依据。     

分块分形插值在农业地学数据模拟中的应用

运用MATLAB计算机编程按照分块分形插值方法对农业地形数据进行了处理.该方法通过对地质采集数据进行分块分形插值,较好地根据少量数据拟合地形并可以借助此法对地形数据进行定量分析.同时,在此基础上进一步探讨了运用此法具体所得预测数据与实际数据相比较,证实其数学模型的可靠性,发现对地形数据的处理是相当精确的.由于这种方法对于具有自相似性的地形地貌特征具有简单可行的特点,且便于运用简单的MATLAB程序实现,因此较易得到有效的推广.     

Production of polyclonal and monoclonal antibodies against gill-associated virus and the development of an ELISA

Gill-associated virus (GAV) is the type species of the genus Okavirus in the Roniviridae of the Nidovirales and has been associated with mortalities in farmed Penaeus monodon (black tiger prawn). Polyclonal antibodies (PAbs) and monoclonal antibodies (MAbs) specific to GAV were produced following immunisation with protein subunits of purified GAV isolated from the gill tissues of P. monodon into either a six week old chicken (PAbs) or into a six week old Balb/c mouse for the production of the MAbs. Western blot analysis indicated that the PAbs reacted with 63, 110 and 170 kDa proteins, while the MAbs reacted to the 20 kDa protein of GAV. The MAbs were further investigated to ensure specificity by immunohistochemistry and elution of affinity purified GAV protein from the MAbs. An enzyme linked immunosorbent assay was then developed using the prepared PAbs and MAbs for the detection of GAV.