不同基因型大豆糖分积累规律的研究——(Ⅱ)蔗糖含量积累规律研究

选用6个不同基因型的大豆品种,运用框栽的方法,研究了大豆蔗糖含量的动态变化。结果表明,大豆植株营养器官中蔗糖含量呈单峰曲线变化,峰值出现在开花期;荚果中的蔗糖含量先升高后降低,叶部和根中的蔗糖含量较高,是合成和贮藏蔗糖的主要部位;茎部蔗糖含量处于最低水平,不同大豆品种间的蔗糖含量没有表现出明显的规律性;绥农14叶片和叶柄的蔗糖积累呈极显著正相关(r=0.945**),丰收10和秣食豆叶片和叶柄蔗糖含量呈显著正相关(r=0.754*,r=0.823*),绥农14和龙选1号叶片和茎的蔗糖含量达到显著正相关水平(r值分别为0.724、0.791)。     

陕西省榆林市一起羊炭疽疫情的紧急流行病学调查

2018年3月11日,陕西省榆林市某养羊户报告该场出现大量羊只死亡。榆林市动物疫病预防控制中心立刻成立专家组,通过现场调查、入户访谈、实验室检测等方法,对该起疫情进行了紧急调查。此次疫情共有45只羊发病死亡,包括15只羔羊(15/18)和30只成年羊(30/50)。综合临床症状、实验室检测和流行病学调查,认为此次疫情是由炭疽杆菌引起的;推测感染原因可能是,畜主多次在埋有炭疽病死羊的深埋点挖土,带出的炭疽杆菌形成芽孢并污染了附近饲料库中的饲料,导致该场羊群感染死亡。提示炭疽疫情的处置,应严格按照《炭疽防治技术规范》进行。     

Eleutheroside B increase tight junction proteins and anti‐inflammatory cytokines expression in intestinal porcine jejunum epithelial cells (IPEC‐J2)

Eleutheroside B (EB) is a phenylpropanoid glycoside with anti‐inflammatory properties, neuroprotective abilities, immunomodulatory effects, antinociceptive effects, and regulation of blood glucose. The aim of this study was to investigate the effects of EB on the barrier function in the intestinal porcine epithelial cells J2 (IPEC‐J2). The IPEC‐J2 cells were inoculated into 96‐well plates at a density of 5 × 10³ cells per well for 100% confluence. The cells were cultured in the presence of EB at concentrations of 0, 0.05, 0.10, and 0.20 mg/ml for 48 hr. Then, 0.10 mg/ml was selected as the suitable concentration for the estimation of transepithelial electric resistance (TEER) value, alkaline phosphatase activity, proinflammatory cytokines mRNA expression, tight junction mRNA and protein expression. The results of this study indicated that the supplementation of EB in IPEC‐J2 cells decreased cellular membrane permeability and mRNA expression of proinflammatory cytokines, including interleukin‐6 (IL‐6), interferon‐γ (INF‐γ), and tumour necrosis factor‐α (TNF‐α). The supplementation of EB in IPEC‐J2 cells increased tight junction protein expression and anti‐inflammatory cytokines, interleukin 10 (IL‐10) and transforming growth factor beta (TGF‐β). In addition, the western blotting and real‐time quantitative polymerase chain reaction (RT‐qPCR) results indicated that EB significantly (p < 0.05) increased the mRNA and protein expression of intestinal tight junction proteins, Claudin‐3, Occludin, and Zonula Occludins protein‐1 (ZO‐1). Therefore, dietary supplementation of EB may increase intestinal barrier function, tight junction protein expression, anti‐inflammatory cytokines, and decrease proinflammatory cytokines synthesis in IPEC‐J2 cells.     

填闲作物甜玉米对太湖地区设施菜地土壤硝态氮残留及淋失的影响

为控制我国南方太湖地区设施蔬菜管理体系中夏季休闲期氮素淋失,减轻其对地下水污染的风险,本田间试验在太湖地区设施菜地夏季揭棚休闲期种植填闲作物(甜玉米),研究了不同施氮条件下甜玉米填闲处理对土壤硝态氮含量、电导率和pH变化的影响,并通过收集淋洗液的方法观测了甜玉米对土壤氮素淋洗及对下茬作物莴苣产量的影响.结果表明:与休闲相比,甜玉米填闲处理可使表层0 ～ 10 cm土壤硝态氮含量从251.4 mg kg-1下降至143.5 mg kg-1,0 ～ 50 cm土壤硝态氮残留减少4.19％～ 30.72％;种植甜玉米可显著降低土壤(0 ～ 10 cm)电导率,降幅达30％以上,但对pH影响不显著.从减少氮素淋洗角度看,甜玉米填闲处理虽不影响淋洗液体积,但可使农民习惯施氮量条件下淋洗液中总氮浓度从102.6 mg kg-1降低至53.7 mg kg-1.与休闲相比,甜玉米填闲处理可减少总氮淋洗30.4％,且对下茬莴苣产量无显著影响.在南方设施菜地夏季休闲期,利用种植填闲作物甜玉米的方式降低土壤氮素淋失风险是较直接有效的措施.     

长期不同施肥措施下潮土冬小麦农田基础地力演变分析

农田基础地力提升对于减施肥料和作物稳产高产有着重大现实意义,该文依托潮土长期定位试验,采用DSSAT(decision support system for agro-technology transfer)模型分析了长期不同施肥条件下冬小麦农田基础地力的演变规律及其影响因素。结果表明,不同施肥显著影响冬小麦的农田基础地力产量,18a连续施用氮磷钾化肥(NPK)、NPK配施有机肥(NPKM)、高量NPK配施有机肥(1.5NPKM)和NPK配施秸秆还田(NPKS)的农田基础地力均得到提升,其基础地力产量分别增加了721、1033、2108和1306kg/hm2,增长率分别为29.6%、42.4%、86.6%和53.7%,平均每年提高1.6%、2.4%、4.8%和3.0%,其中以1.5NPKM处理更能有效提高冬小麦农田基础地力产量。1991-2008年冬小麦的基础地力贡献率在36.5%～70.9%,各处理18a年均基础地力贡献率分别为42.5%、59.9%、58.9%和52.5%,大小顺序为NPKM>1.5NPKM>NPKS>NPK,说明有机肥或秸秆与化肥配施比单施化肥更能有效提高农田基础地力产量及地力贡献率。基础地力贡献率与土壤全钾、全磷含量无显著相关性,与土壤有机碳、全氮、碱解氮、有效磷、速效钾含量均达到了极显著相关,其中有机碳和全氮与基础地力贡献率相关度最高,说明土壤有机碳和全氮是潮土区基础地力的主要影响因素,是潮土区基础地力的主要评价指标。     

对动物疫病防治体制改革的几点设想

随着改革开放步伐加快，全球经济一体化逐步形成，我国与国际动物疫病防治体制的接轨已势在必行，我国的动物疫病防治体制将面临新的挑战，对现行的动物疫病防治进行改革和完善，已迫在眉睫。     

简述路面弯沉的测试

本文作者详细介绍了4种弯沉测试技术及测试原理、技术特点、弯沉数据的修正及其评定。     

基于MATLAB的数据采集系统的研究

由于MATLAB不能直接对硬件端口进行读写操作,缺乏了实时性,使得工程上的应用受到了极大的限制。而通过MATLAB应用程序接口Mex调用C 语言,可实现在MATLAB环境下对硬件端口信号的读写。为此,笔者对Mex接口文件进行了详细介绍,包括Mex接口的各种特殊功能、详细编写规则和具体编译要求,具体阐述了Mex接口在MATLAB环境下的调用及使用。并根据Mex接口的相关功能,对MATLAB数据采集系统的设计在理论上进行了探讨,以图对MATLAB功能进行进一步的扩展。     

黑龙江省无公害大豆生产中的病虫害防治技术

针对黑龙江省无公害大豆生产中的病虫害,提出了包括土壤管理、种子管理、化学防治综合防治技术措施.以期为黑龙江省无公害大豆生产中的病虫害防治提供技术依据.     

Amur tigers and leopards returning to China: direct evidence and a landscape conservation plan

Context

The Amur tiger and leopard, once roaming over the Eurasian continent, are now endangered and confined to the Sikhote-Alin Mountains, Russia—a landscape that has been increasingly fragmented due to human activities. The ultimate fate of these big cats depends on whether they can resettle in their previous main historical range in NE China. Recent sightings of these animals along the China–Russia border have aroused new hope, but direct evidence is lacking.

Objectives

The main objectives of our study were (1) to determine the abundance and spatiotemporal patterns of tigers, leopards, and primary prey; (2) to investigate factors influencing the resettlement of the two big cats; and (3) to propose a landscape-scale conservation plan to secure the long-term sustainability of the Amur tiger and leopard.

Methods

We monitored the two felids, their prey, and human activities, with 380 camera-trap stations, for a total of 175,127 trap days and over an area of 6000 km² in NE China. We used the constraint line method to characterize cattle grazing and human influences on tigers, leopards, and their prey species.

Results

Our results show that, unexpectedly, at least 26 tigers and 42 leopards are present within China, which are confined primarily to a narrow area along the border with Russia. We have further identified that cattle grazing and human disturbances are the key hurdles to the dispersal of the tigers and leopards farther into China where suitable habitat is potentially available.

Conclusions

Amur tigers and leopards are returning to China, indeed, but their long-term resettlement is not likely without active and timely conservation efforts on landscape and regional scales. To overcome the hurdles to the resettlement of tigers and leopards in China, we propose a “Tiger and Leopard Resettlement Program” that will engage the government, local communities, and researchers, so that the long-term sustainability of the Amur tigers and leopards can be ensured.