欧盟国家非洲猪瘟流行情况及对我国防控工作的启示

非洲猪瘟(ASF)1957年首次扩散到欧洲,2014年再次从高加索地区传入,并迅速在波罗的海周边国家蔓延,至2018年4月已扩散至欧盟8个成员国,且逐渐呈现地方性流行态势。本文重点介绍了欧洲国家的ASF扩散史,综述了病毒在欧盟国家扩散的主要途径,梳理了欧盟的ASF防控法规和措施,并对我国ASF防控提出了建议,以期为ASF防控提供帮助。     

Effect of Different Concentrate-roughage Ratios on Rumen Degradability of Cassava Stems and Leaves Total Mixed Ration in Goat

The rumen degradations of TMR were studied in this experiment,in which cassava stems and leaves were used as roughage and formulated with concentrate in different proportions.The purpose of this study was to formulate the available TMR for finishing goat,and provide a theoretical basis for the applications of cassava stems and leaves in goat production.Six Hainan Black goats with permanent rumen fistulas were selected,the rumen degradabilities of DM,CP,NDF and ADF of TMR with 6 different concentrate to forage ratio（2:8,3:7,4:6,5:5,6:4 and 7:3）were tested using nylon bag method.The results showed that,the DM effective degradabilities at the ratio of 4:6,5:5,6:4,7:3 were significantly higher than that of 2:8 and 3:7（P<0.05).CP effective degradabilities at the ratio of 2:8,3:7,4:6 were significantly higher than that of 5:5,6:4 and 7:3（P<0.05).The NDF effective degradation at the ratio of 5:5 was significantly higher than that in the other groups（P<0.05).The ADF degradation at the ratio of 3:7 was significantly higher than that of 4:6,5:5, 6:4 and 7:3（P<0.05).The results indicated that,the nutrient degradation in rumen were higher when the concentrate to forage（cassava stems and leaves）ratio in TMR were 3:7,4:6 and 5:5,and the recommended ratio range were 4:6 to 5:5 in production practice.     

Proton accumulation accelerated by heavy chemical nitrogen fertilization and its long-term impact on acidifying rate in a typical arable soil in the Huang-Huai-Hai Plain

Cropland productivity has been signiifcantly impacted by soil acidiifcation resulted from nitrogen (N) fertilization, especialy as a result of excess ammoniacal N input. With decades’ intensive agricul...     

西吉县农用地膜应用污染现状及对策

本文就西吉县农用地膜的应用现状和污染现状进行了分析,并就这一现状提出了促进旱作农业可持续发展的对策措施。     

Identification of organic acid-related genes and their expression profiles in two pear (Pyrus pyrifolia) cultivars with difference in predominant acid type at fruit ripening stage

‘Yandangxueli’ is a pear cultivar with predominant citric acid in the ripe fruit, different from most of pear cultivars such as ‘Gengtouqing’ in which malic acid is the predominant acid type. It was found that ‘Yandangxueli’ accumulated citric acid for three times against that in ‘Gengtouqing’ at fruit ripening stage. To investigate the mechanism of citric acid accumulation in ‘Yandangxueli’, organic acids content, gene expression and enzyme activity were studied in both cultivars. Five genes, Pp:mtCs, Pp:cyAco, Pp:cyIdh, Pp:mtMdh and Pp:cyMe which encoded citric synthase (CS), cytosolic aconitase (cyACO), NADP-dependent isocitrate dehydrogenase (NADP-IDH), NAD-dependent malate dehydrogenase (NAD-MDH) and NADP-dependent malic enzyme (NADP-ME) respectively, were identified from pear fruit. Their expression profiles and the corresponding enzyme activities were determined throughout fruit development in both cultivars. Results from these enzymes indicated that there were no strict relationship between gene expression, enzyme activity and citric acid accumulation. Expression analysis for two Py:vVAtp genes encoding vacuolar H⁺-ATPase A subunit and one Py:vVpp gene encoding Vacuolar H⁺-pyrophosphatase showed that they were all with up-regulated expression at the later development stage of ‘Yandangxueli’ but with down-regulated expression in ‘Gengtouqing’. Therefore, it is concluded that the different ability in citric acid transportation and storage might be involved in the high citric acid content in ‘Yandangxueli’.     

生猪养殖规模成本与收益的比较研究

文章通过对1991~2012年我国生猪散养和规模养殖的有关成本和收益的比较分析后发现,生猪养殖的风险在不断加大,散户养殖的成本高于规模养殖,差距在不断扩大;散户养殖的收益低于规模养殖;虽然规模养殖的物质与服务成本高于散户养殖,但人工成本远低于散户养殖;规模养殖的单位用工量和平均饲养周期低于散户养殖。基于上述比较分析的结论,得出发展规模化养殖的几点启示。     

不同浓度褪黑素对氯化钠胁迫下宝岛蕉幼苗的影响

为了研究不同浓度褪黑素对宝岛蕉幼苗氯化钠胁迫的影响,使用不同浓度褪黑素处理宝岛蕉幼苗叶片,研究处理后宝岛蕉幼苗叶片和根系的可溶性糖、丙二醛、脯氨酸含量及叶质膜透性的变化。结果表明,褪黑素100μmol/L能够降低宝岛蕉幼苗叶质膜透性,提高叶片和根系可溶性糖含量,降低叶片和根系丙二醛含量,提高叶片和根系脯氨酸含量,提高幼苗耐盐性,以缓解氯化钠胁迫对宝岛蕉幼苗的伤害。     

桃果实中多菌灵残留量的高效液相色谱-串联质谱结合QuEchERS检测方法

为分析桃果实中多菌灵残留量,采用QuEchERS方法对样品进行前处理,建立了快速检测桃果实中多菌灵残留量的高效液相-串联质谱法。样品经乙腈提取、QuEchERS方法脱水盐析和萃取净化,采用InertsilODS-2(5mm,150mm×2.1mm)色谱柱进行分离,梯度洗脱,在多反应检测模式下测定。经方法学验证,在添加不同浓度的标准溶液时,多菌灵残留量的平均回收率为89.5%~94.4%,RSD为1.95%。该方法简单、快速,准确度高,能够满足多菌灵残留分析的要求。     

基于NoteExpress（NE）的文献管理——从检索文献到论文写作

基于NoteExpress的文献管理功能,以日常科研论文写作为基准,从检索文献开始到利用NE的各项功能过滤筛选文献,到插入参考文献直至论文写作完成、发表等方面,来说明怎样利用NE的检索、管理、写作功能来科学管理文献,提高写作效率。