Global occurrence and spread of highly pathogenic avian influenza virus of the subtype H5N1

Highly pathogenic avian influenza viruses of the subtype H5N1 (HPAIV-H5N1) have circulated continuously in Asia, Europe, and Africa since 2003. Investigations on the environmental preference and global spread processes of the virus are needed. We compiled 16 environmental variables to assess their correlation with HPAIV-H5N1 occurrences by using a niche-based model called Maxent. We found the virus had the strongest positive association with the human footprint index, as well as the presence of certain types of wetlands and mild temperature (10-30 C). Outbreaks of HPAIV-H5N1 in poultry or wild birds were also more frequent in certain major habitat types (e.g., tropical and subtropical moist broadleaf forests, temperate broadleaf and mixed forests, and flooded grasslands and savannas) and ecoregions. We conducted trend surface analysis to generate the travelling wave of the virus' global spread from 2003 to 2009, which indicated that high mountains or plateaus did not affect the spread speed and direction.     

Three novel single-nucleotide polymorphisms of MBL1 gene in Chinese native cattle and their associations with milk performance traits

Mannan-binding lectin (MBL), a pattern recognizing serum protein, participates in the innate immune system of mammals as an opsonin. In humans, single-nucleotide polymorphisms (SNPs) in MBL2 gene were found to cause various innate immune dysfunctions. In the present study, we discovered three single-nucleotide polymorphisms of the MBL1 gene in Chinese native cattle and analyzed their associations with milk traits. By screening the genetic variation of MBL1 in 1053 individuals of three Chinese native cattle breeds including China Holstein, Luxi Yellow and Bohai Black using created restriction site–polymerase chain reaction (CRS–PCR), PCR–restriction fragment length polymorphism (PCR–RFLP) and DNA sequencing techniques, three new SNPs, g.855G>A, g.2651G>A and g.2686T>C, were found to have allele frequencies of 0–12.65%, 24.07–42.39% and 56.95–73.68%, respectively. While SNP g.855G>A is located within intron ?, the other two SNPs reside in the exon II region with one mutation being non-synonymous (GTT (Val) > ATT (Ile)) and the other synonymous (GCT (Ala) > GCC (Ala)). Among the 596 Chinese Holstein cattle with at least 3 lactation Dairy Herd Improvement (DHI) records, eight different haplotypes and 19 genotype combinations were detected. Statistical analyses revealed no correlation between either g.855G>A or g.2686T>C and somatic cell score (SCS), however significant association was found between g.2651G>A and SCS, suggesting a possible role of this SNP in the host response against mastitis. Our data also suggested that the combined genotypes of GGC/AAC with the lowest SCS, AAT/AAT with the highest protein content and AGC/AGC with the highest 305-d milk yield were favorable combinations for mastitis resistance and milk production traits. Therefore, GGC/AAC, AAT/AAT and AGC/AGC can be used as possible candidates for marker-assisted selection in the dairy cattle breeding program.     

MSTN基因对牛肌动蛋白细胞骨架调节通路的影响

为探究肌肉生长抑制素（myostatin,MSTN）对牛骨骼肌生长发育的作用机制,本研究前期利用定量蛋白质组学与磷酸化蛋白质组学分析野生型蒙古牛（MG.WT）和MSTN^+/-蒙古牛（MG.MSTN^+/-）腿臀肌肌肉组织中蛋白质水平和磷酸化修饰水平的差异变化,使用已建立的牛骨骼肌卫星细胞体外诱导成肌分化模型,检测设计合成的MSTN siRNA （si-MSTN）干扰效果;采用实时荧光定量PCR和Western blotting方法检测转染si-MSTN的增殖期（GM）和分化第3天（DM3）牛骨骼肌卫星细胞中肌动蛋白细胞骨架调节通路相关基因的mRNA和蛋白水平的表达变化,研究敲低MSTN表达对肌动蛋白细胞骨架调节通路的影响。结果显示,在MSTN^+/-蒙古牛肌肉组织中共鉴定到16个肌动蛋白细胞骨架调节通路相关基因表达丰度上调;转染si-MSTN细胞中的MSTN表达水平极显著降低（P<0.01）;在转染si-MSTN的GM期牛骨骼肌卫星细胞中,肌动蛋白细胞骨架调节通路相关基因ENAH、ACTN4和Cdc42的mRNA水平均显著升高（P<0.05）,PFN1、RhoA和ACTN4的蛋白水平均显著或极显著升高（P<0.05;P<0.01）;在转染si-MSTN的DM3牛骨骼肌卫星细胞中,ENAH、CFL1、SCIN和Cdc42基因mRNA水平均显著升高（P<0.05）,RhoA基因mRNA水平极显著升高（P<0.01）,PFN1和ACTN4的蛋白水平均显著升高（P<0.05）。结果表明,干扰MSTN可以促进肌动蛋白细胞骨架调节通路相关基因的表达,探明了MSTN可能通过介导肌动蛋白细胞骨架调节通路影响牛骨骼肌卫星细胞增殖和成肌分化的分子机制,为进一步研究MSTN对牛成肌分化的调控机制提供参考。     

发酵花生壳对育肥猪生产性能、胴体性状、肉品质及经济效益的影响

本试验旨在研究发酵花生壳对育肥猪生产性能、胴体性状、肉品质及经济效益的影响。选用100头50 kg左右、健康的杜×长×大三元杂交育肥猪,随机分成5组,每组4个重复,每个重复5头猪。对照组饲喂玉米—浓缩料型基础日粮,试验1~4组分别饲喂在基础日粮中添加10%发酵花生壳、20%发酵花生壳、30%发酵花生壳、15%发酵玉米秸秆的试验日粮,试验期66 d。结果表明,对照组及试验2、3组平均日采食量显著高于试验1、4组(P<0.05),对照组和试验3组平均日增重显著高于试验1、4组(P<0.05),各组间料重比差异均不显著(P>0.05),试验1、2、3、4组腹泻频率均极显著低于对照组(P<0.01);各组间胴体质量、屠宰率、背膘厚度、眼肌面积差异均不显著(P>0.05),试验2组瘦肉率显著低于对照组和试验1组(P<0.05);各组间大理石纹、肉色、嫩度、肌内脂肪、失水率及熟肉率差异均不显著(P>0.05),但试验1、2、3、4组失水率低于对照组,差异不显著(P>0.05);根据经济效益分析表明,在育肥猪从50~90 kg阶段,对照组每头猪平均盈利47.60元,试验1、2、3、4组每头猪平均盈利分别为56.40、60.40、78.80、58.80元,其中试验3组最优。综合上述的分析结果可知,发酵花生壳对育肥猪生长性能、胴体性状、肉品质无不良影响,且能有效地降低育肥猪的腹泻频率,提高猪肉的系水力,适当的添加可有效地降低饲养成本,提高经济效益。     

坡面材小蠹卵的饲养技术初探

梅州局在 1996年 6月从市某家具厂进口的印度尼西亚松木板上检出坡面材小蠹Ｘｙｌｅ ｂｏｒｕｓｉｎｔｅｒｊｅｃｔｕｓＢｌａｎｄｆｏｒｄ成虫。 1998年 5月对该厂从印度尼西亚进口的木板实施检疫时 ,发现 1长条木板上有很多长 3～ 6ｃｍ的坑道 ,经仔细检查 ,发现有 14粒长约     

细菌性条斑病稻种带菌快速检测方法研究

 建立15株分泌抗水稻细菌性条斑病(RBLS)特异性单克隆抗体(McAb)的杂交瘤细胞。对RBLS病菌呈阳性反应,与植物病原细菌5个属的其它检测菌株均无交叉反应。以酶联免疫吸附试验(ELISA)间接法对30份人工接种稻种进行检测,28份呈阳性反应,检出阳性率达93.3%;对46份病田稻种进行检测,36份呈阳性反应,10份呈阴性反应。取检测为阳性反应中的11份病田稻种的浸出液接种稻苗,有7份发病;而10份检测阴性反应的病田稻种浸出液的接种稻苗均无发病。该检测法灵敏度为0.0125-0.00125mg/ml(蛋白浓度)。     

Effects of light quality on conidiophore formation of the melon powdery mildew pathogen <Emphasis Type="Italic">Podosphaera xanthii</Emphasis>

The lengths of conidiophores in fungal colonies of the melon powdery mildew pathogen Podosphaera xanthii Pollacci KMP-6 N cultured under greenhouse (natural) conditions differed markedly from those cultured in a growth chamber. We hypothesized that light wavelength was responsible for the differences in conidiophore length. In this study, we examined the effects of light-emitting diode (LED) irradiation (purple, blue, green, orange, and red light) and white light on colony development and conidiophore formation in KMP-6 N using a stereomicroscope and a high-fidelity digital microscope. Colonies on leaves were flat under greenhouse conditions and under red LED light irradiation but were stacked under growth chamber conditions and under purple, blue, green, and orange LED light irradiation. In addition, KMP-6 N formed catenated conidia comprising six conidia per conidiophore under greenhouse conditions and red light but more than seven conidia per conidiophore under growth chamber conditions and purple, blue, green, and orange light. Furthermore, almost none of the conidia on top of the conidiophores grown under blue light were fully constricted. Therefore, these fungi could not scatter their conidia and spread infection. This is the first report of the effects of LED lights on conidiophore formation in the melon powdery mildew fungus P. xanthii. The results provide insight into the mechanisms underlying the responses of conidiophores to light of specific wavelengths and conidial scatter from conidiophores of melon powdery mildew fungi.     

进境美国苹果果实中黑斑病病原的初步鉴定

从美国进境苹果中截获的链格孢Alternaria sp．，经分离纯化后，得到菌株（MP1），通过观察其产孢表型、孢子的形态特征以及接种试验后的病果症状，初步确定为苹果黑斑病菌Alternaria mali Roberts。     

巴氏新小绥螨和尼氏真绥螨的耐饥能力及饥饿对二者捕食朱砂叶螨功能的影响

试验温度25℃条件下,室内测定我国农作物害虫的常用生物防治剂—巴氏新小绥螨Neoseiulus barkeri Hughes和尼氏真绥螨Euseius nicholsi Ehara et Lee的耐饥能力,以及定量分析不同饥饿程度对两种捕食螨捕食朱砂叶螨的功能反应和捕食速度的影响。研究结果表明：两种捕食螨各螨态的耐饥时间与发育历期呈显著正相关（P﹤0.05）。各螨态的阶段存活率与存活时间之间的关系均可用二次抛物线拟合。根据饥饿半致死和致死时间（T50和T95）,巴氏新小绥螨的耐饥能力明显强于尼氏真绥螨。除巴氏新小绥螨雌成螨的耐饥性存活曲线呈拱形外,两种捕食螨其它螨态的耐饥性存活曲线均呈凹形。不同饥饿程度的两种捕食螨雌成螨捕食朱砂叶螨若螨的功能反应均为HollingⅡ型,饥饿程度不能改变它们的捕食功能反应类型,但可使功能反应模型的各参数值发生较大改变。饥饿24 h的巴氏新小绥螨和尼氏真绥螨雌成螨对朱砂叶螨若螨的捕食作用主要集中在取食的前8 h阶段,而未经饥饿处理的两种捕食螨雌成螨在开始捕食的24 h内各阶段的捕食速度变化不大。因此,饥饿处理对两种捕食螨雌成螨的捕食作用有明显影响。     

绿柳突瓣叶蜂生物学及防治

绿柳突瓣叶蜂(Nematus ruyanus Wei)是发生在甘肃天水柳树上的一种新害虫。严重危害旱柳、垂柳、金丝柳等多种柳树,1年发生6代,非越冬茧结于叶背,越冬茧结于1-5 cm表土中,以预蛹在越冬茧内越冬。幼虫食叶危害,每年3月下旬至10月下旬是该虫的猖獗危害期。用25%灭幼脲,1.8%阿维菌素乳油,40%氧乐果乳油2000倍液防治3龄前幼虫防效达95%以上;用2.5%溴氰菊酯乳油,3%高渗苯氧威乳油4000倍液喷冠防治3龄后大幼虫防效可达90%以上。