内生真菌和水引发对NaCl胁迫条件下中华羊茅种子萌发的影响

本试验以带Epichloё内生真菌(E+)及不带内生真菌(E-)中华羊茅种子为研究材料,研究其水引发后,在NaCl胁迫条件下的萌发情况。结果表明,NaCl胁迫显著降低中华羊茅种子发芽率、发芽势、发芽指数、胚芽长、胚根长和干重。除对照处理外,相对于不带内生真菌的中华羊茅种子,内生真菌能显著提高不同NaCl浓度胁迫条件下中华羊茅种子的萌发力及幼苗生长。水引发与内生真菌可产生互作,在引发时间为20 min时与内生真菌的互作效果最为明显,在不同NaCl浓度胁迫下中华羊茅种子各萌发指标及幼苗生长情况均显著高于其他处理。在对各指标的相关性分析显示,中华羊茅种子的发芽率、发芽势、发芽指数、胚芽长、胚根长和干重相互之间均呈极显著正相关。     

土壤中南方根结线虫的实时荧光PCR检测和定量

为了准确测定土壤中南方根结线虫Meloidogyne incognita的群体密度,根据序列特异性扩增区标记设计了南方根结线虫特异性引物和TaqMan探针,分别建立了卵和2龄幼虫的实时荧光PCR定量检测体系,并将该检测体系与显微镜计数法进行了比较.结果表明,引物Mi-F/R及探针Mi-probe对南方根结线虫具有高度特异性,建立的标准曲线循环阈值与卵和2龄幼虫数量的对数值之间具有良好的线性关系,相关系数分别为0.9771和0.9853,扩增效率均为90％,检测灵敏度为10-1个卵及10-3条2龄幼虫;对10个田间土壤样本的检测显示,实时荧光PCR定量检测与显微镜计数法测定的南方根结线虫卵和2龄幼虫数量呈显著正相关,且两种方法对2龄幼虫的测定结果无显著差异.     

奶水牛乳中体细胞数与乳成分的相关分析

乳汁体细胞数(somatic cell count,SCC)是检查奶牛乳房炎和牛奶质量的指标,为了解南宁某规模化奶牛场奶水牛SCC情况及SCC与其他乳成分的关系,试验随机选取该场152份泌乳早期乳样,测定其SCC、乳汁比重、蛋白质、脂肪、总固形物、非脂固形物及乳糖的含量,并对其进行相关性分析。结果表明,SCC小于50万/mL的乳样占被检奶样总数的88.16%,大于100万/mL的占1.97%;乳汁比重、乳蛋白、乳糖和非脂固形物含量均随着SCC的升高而下降,而乳脂含量随着SCC的升高而呈上升趋势;SCC与乳糖及非脂固形物含量呈极显著负相关(P<0.01)。因此,奶水牛乳中SCC不仅与乳糖和非脂固形物含量密切相关,也提示其与奶水牛产后营养代谢状况有关。     

Low levels of haptoglobin and putative amino acid sequence in Taiwanese Lanyu miniature pigs

Porcine haptoglobin (Hp) is an acute phase protein. Its plasma level increases significantly during inflammation and infection. One of the main functions of Hp is to bind free hemoglobin (Hb) and inhibit its oxidative activity. In the present report, we studied the Hp phenotype of Taiwanese Lanyu miniature pigs (TLY minipigs; n=43) and found their Hp structure to be a homodimer (beta-alpha-alpha-beta) similar to human Hp 1-1. Interestingly, Western blot and high performance liquid chromatographic (HPLC) analysis showed that 25% of the TLY minipigs possessed low or no plasma Hp level (<0.05 mg/ml). The Hp cDNA of these TLY minipigs was then cloned, and the translated amino acid sequence was analyzed. No sequences were found to be deficient; they showed a 99.7% identity with domestic pigs (NP_999165). The mean overall Hp level of the TLY minipigs (0.21 +/- 0.25 mg/ml; n=43) determined by enzyme-linked immunosorbent assay (ELISA) was markedly lower than that of domestic pigs (0.78 +/- 0.45 mg/ml; p<0.001), while 25% of the TLY minipigs had an Hp level that was extremely low (<0.05 mg/ml). In addition, the initial recovery rate (first 40 min) in the circulation of infused fluorescein isothiocyanate (FITC)-Hb was significantly higher in the TLY minipigs with extremely low Hp levels than those with high levels. This data suggests that the low concentration of Hp-Hb complex is responsible for the higher recovery rate of Hb in the circulation. TLY minipigs have been used as an experimental model for cardiovascular diseases; whether they can be used as a model for inflammatory diseases, with Hp as a marker, remains a topic of interest. However, since the Hp level varies significantly among individual TLY minipigs, it is necessary to prescreen the Hp levels of the animals to minimize variation in the experimental baseline. The present study may provide a reference value for future use of the TLY minipig as an animal model for inflammation-associated diseases.     

北京市马属动物赛事监管制度的建立

通过对近年来重大马术活动的监管,结合《北京市动物防疫条例》的实施,北京市逐步形成马属动物展览演出比赛的“赛事报告、报检报验、档案记录、防疫条件审查、隔离观察、赛中监管、应急预备和宣传告知”八大监管制度,确保了北京市马属动物无疫安全。     

赖氨酸采食量对早期断奶仔猪生长发育及胰腺内分泌机能的影响

将55头21日龄断奶的雄性仔猪随机分为5组，各组仔猪饲喂赖氨酸含量为0．60％、0．80％、1．00％、1．20％和1．40％的试验日粮21d。42日龄结束饲养试验时进行葡萄糖灌注试验，观察赖氨酸采食量对早期断奶仔猪生长发育和胰腺内分泌的影响。结果表明：早期断奶仔猪体增重与赖氨酸采食量为强正相关，根椐体增重指标，21～42日龄阶段，仔猪的赖氨酸采食量不应低于3．16g／d，日粮赖氨酸含量不应低于1.40％。赖氨酸严重缺乏(采食量小于1．45g／d)时，胰岛素的分泌量下降，对高血糖应激的反应能力降低。     

β-carotene attenuates weaning-induced apoptosis via inhibition of PERK-CHOP and IRE1-JNK/p38 MAPK signalling pathways in piglet jejunum

Weaning may cause oxidative injury, immune response impairment, apoptosis and other injuries in piglets. Oxidative and endoplasmic reticulum stress (ERS) can elicit inflammatory responses, and persistent oxidative and ERS also may lead to apoptotic cascades, which is associated with the pathogenesis of multiple diseases. β-carotene, a natural carotenoid, has potential anti-inflammatory and antioxidant functions. However, the effect of β-carotene on apoptosis in weaned piglets and the detailed molecular mechanism remain unclear. In this study, we found that β-carotene decreased malondialdehyde (MDA) levels and increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in piglet serum. β-carotene could inhibit the mRNA levels of caspase-3 significantly, but had no significant inhibitory effect of the mRNA levels of caspase-9 and caspase-12 in the piglet jejunum. In addition, β-carotene decreased the activation of GRP78, CHOP, and JNK/p38 MAPK and the ratio of Bax/Bcl-2. Furthermore, β-carotene had a significant influence on the activation of ERS and apoptosis-related signals in TG-induced IPEC-J2. In the present study, β-carotene pre-treatment attenuated the ratio of Bax/Bcl-2 and prevented TG-induced increases in the level of PERK-CHOP and IRE1-JNK/p38 MAPK pathway activation in a dose-dependent manner. Overall, these findings indicate that β-carotene may protect weaning-induced apoptosis through inhibiting ERS.     

在灰潮土-芹菜系统中包膜尿素和尿素氮的利用和去向

通过盆栽试验研究了包膜尿素(自制)和尿素等肥料在灰潮土中对芹菜生长、氮吸收、产量和品质等的影响。结果表明：在2种质地的灰潮土中施包膜尿素较尿素使芹菜增产11．5％～15．2％,N吸收增加5．9％～9．5％,土壤氨挥发损失N减少12．2％～14．4％,淋失和反硝化N损失减少25．5％～28．3％,N素利用率提高20．1％～27．9％,土壤持留N量占施氮量的32．0％～37．3％;芹菜产品中NO3^--N含量降低44．2％～60．3％,维生素C含量显著提高,品质明显得到改善。     

美国公共放牧地管理政策演进的历史经验

当初步遏制草地退化后,我国当前迫切需要对草地管理政策进行优化和调整,进而更好地通过草畜平衡和生态补贴实现生态保育和牧民利益的协调和可持续发展目标。长达90年的美国公共放牧地政策可以为我国调整和优化草地管理政策提供借鉴。美国经验表明,实现草地生态保育需要在社会共识、法律体系和行政管理等方面,牢固地树立和实现草地的多重功能和生态系统服务理念。进一步地,公有的草地产权制度是保障草地多重生态系统服务的法律前提,非牧产业发展是实现草地多重功能的经济基础,精细的行政管理是实现草地生产生态平衡的技术保障,多种利益主体参与是实现草地管理制度改革的活力来源。美国草地管理制度发展的曲折反复,也说明了生态管理政策的失效和调整,禁牧和监管强度的张弛反复,不同利益集团的矛盾诉求和博弈消长,都是草地治理中的正常情况。我国草地治理也可能经历复杂曲折的过程。在下一阶段,草地产权的优化、行政管理的精细化、牧民利益和生态保育目标的协调,是实现我国草地可持续治理的核心要务。     

伪狂犬病病毒gB蛋白抗原表位基因串联构建及原核表达

本试验通过自行设计两段引物,利用重叠延伸PCR方法,将伪狂犬病病毒(PRV)gB基因两段优势抗原表位序列串联,克隆至pMD18-T载体,测序正确后双酶切连接至pET-32a(+)载体,构建重组质粒;重组质粒转化入大肠杆菌BL21(DE3)受体菌,经IPTG诱导后,通过SDS-PAGE和Western blotting检测融合蛋白表达情况。经检测,诱导后的重组蛋白获得表达,重组蛋白大小约为54ku,其中串联蛋白大小约为34ku。该重组蛋白可与伪狂犬病病毒gB蛋白单克隆抗体发生特异性反应,表明重组蛋白的抗原性良好。