过量使用抗倒酯对海滨雀稗草坪生长的影响

抗倒酯(Trinexapac-ethyl,TE)具有抑制草坪垂直生长,减少修剪频率的作用,近年来被广泛应用于高尔夫球场草坪,但常常因为过量使用而造成草坪伤害。为此,本研究分别对3种抗倒酯类产品(P、M、N)设置常规浓度(1mL·L~(-1))、中高浓度(1.5mL·L~(-1))、特高浓度(2mL·L~(-1))、超高浓度(10mL·L~(-1)),通过比较其对海滨雀稗(Paspalum vaginatum)草坪草屑量、生物量、颜色、密度、生长速度的影响,为抗倒酯产品的合理使用提供参考依据。结果表明,与清水对照相比,产品P、M、N在常规浓度下,草屑量分别下降70.0%、78.5%、80.0%,生长速度分别下降66.0%、51.5%、53.6%;超高浓度下,草屑量分别下降82.2%、87.8%、81.3%,生长速度分别下降71.1%、72.2%、83.6%,浓度越高下降幅度越大,但不同浓度处理间差异不显著(P0.05)。不同浓度处理对生物量影响也不显著。P、M、N这3种产品超高浓度处理使草坪草颜色分别从常规浓度处理的7.9、7.9、8.0分下降到7.3、7.2、7.2分,使草坪草密度分别从常规浓度处理的8.1、8.1、8.2分下降到7.5、7.4、7.4分。综合分析得出,在1 mL·L~(-1)常规浓度下,产品P对草坪生长速度抑制最强,且对草屑量、草坪颜色和密度影响较小,调控效果最好。过量使用抗倒酯不仅抑制效果不再明显,还会降低草坪质量。     

内蒙古羊屠宰场致泻性大肠杆菌和沙门氏菌污染状况分析

为了解内蒙古地区羊屠宰场各屠宰环节致泻性大肠杆菌和沙门氏菌的携带情况,评估是否存在污染风险,选取不同规模屠宰场,用棉拭子法分别采集不同屠宰环节样品349份,36 h内进行试验;应用PCR方法分离鉴定病原菌,对鉴定为致泻性大肠杆菌的分离株进行16S r DNA测序并构建系统发育树。结果显示:从刚宰杀的羊胴体表面和环境中共分离到致泻性大肠杆菌12株,其中11株携带毒力基因elt,1株携带毒力基因eae和elt;大中型屠宰场(1.21%)的致泻性大肠杆菌阳性率低于小型屠宰场(5.43%),不同规模屠宰场的预冷间均未检出致泻性大肠杆菌和沙门氏菌;从屠宰环境中分离出1株携带inv A基因的沙门氏菌,阳性率为0.29%;经高压冲洗和排酸预冷等屠宰工艺后,在羊胴体表面均未发现致泻性大肠杆菌和沙门氏菌。     

检疫犬基地建设与发展策略探讨

检疫犬应用技术作为一种特殊的检验检疫手段,目前已被30多个国家或地区应用于检验检疫领域。许多国家或地区已建有自己的国家级工作犬训练基地。近年来,由于出入境业务量的迅速增长,我国对检疫犬数量的需求逐年攀升,明确要建成2个国家级检疫犬繁殖训养中心。检疫犬基地作为培养检疫犬的重要场所,其基地面积、位置规划、人力资源、种犬储备、幼犬来源等的科学合理规划,对保证其可持续发展具有重要意义。检疫犬基地的可持续发展,需要准确定位功能需求,搞好种犬繁育,统筹储备人力资源,建设生态环保基地,挖掘和利用社会资源,以及拓展其它功能建设,从而做到行业引领。     

一起销售劣兽药案的查处与思考

云南省德宏州动物卫生监督所通过抽检发现,辖区内某兽药经营服务部涉嫌销售劣兽药。经该县农业局立案调查,认定当事人违法事实清楚,证据充分,根据《兽药管理条例》规定,依法给予了行政处罚。本文重点介绍了案件来源、调查过程、处理情况等执法内容。分析了案件定性、执法主体适格、自由裁量权应用、保护当事人合法权益等问题,以期为同类案件查处提供参考。     

Response of labile organic C and N pools to plastic film removal from semiarid farmland soil

To examine the effects of plastic film removal on grain yield and soil organic matter (SOM), a spring maize (Zea may L.) field experiment was conducted for 5 yr at Changwu Agricultural and Ecological Experimental Station of Northwest China. Compared with traditional plastic film mulching during entire growing stages (FM), plastic film removal at the silking stage (RM) resulted in a 6.3% higher average maize yield. Under the RM treatment, soil organic carbon and total nitrogen significantly increased after the 5‐yr cultivation in the 0‐ to 20‐cm layer. Significant increases in extractable organic C (EOC), KMnO₄‐oxidizable C (KMnO₄‐C) and C management index (CMI) in the 0‐ to 20‐cm layer, and light fraction organic C and EOC in the 20‐ to 40‐cm layer were observed in response to plastic film removal after the 1‐yr treatment; the responses were more significant after 5 yr. Under the RM treatment, significant increases in microbial biomass C, light fraction organic N, extractable organic N, KMnO₄‐C and CMI were also observed after five years in the 20‐ to 40‐cm layer. Moreover, KMnO₄‐C and EOC were much more sensitive than other labile SOM fractions to the application of RM, even after only 1 yr of cultivation. Therefore, compared with mulching for the whole growing season, plastic film removal at the maize silking stage is an effective option for increasing yields and enhancing SOM concentration and soil sustainability in the regions with semiarid monsoon climates that have sufficient rainfall during maize reproductive stages.     

广东惠州生猪养殖现状调查及分析

惠州地处广东省珠江三角洲,近10多年城市化进程速度加快,城市人口增长迅速,随着人们生活水平不断提高,猪肉消费急速上升.同时,惠州也是广东省猪场最为集中的地区,是广东重要的肉猪、种猪生产基地.惠州地区规模生猪养殖发展之路更是广东省生猪养殖的一个缩影和风向标.通过深入基层调查,走访养殖户、屠宰场、大型养殖企业等,通过座谈交流、问卷调查和查阅生产记录的方式,对惠州不同规模生猪养殖发展现状及面临的主要问题进行了调查和分析.通过分析发现,中等规模的生猪养殖场（存栏500-2 999头）具有生产效益明显、环境容量合适、调整生产快、抗风险高和适合精细饲养等特点,比较适合目前惠州的生猪养殖发展.针对惠州面临的产业结构调整、划定动物禁养区等现实问题,本文提出应结合人文发展,完善行业标准,大力发展现代都市养殖模式-绿色生态园区的建议.     

The localization and expression of epidermal growth factor and epidermal growth factor receptor in bovine ovary during oestrous cycle

Epidermal growth factor (EGF) is one of the important regulatory factors of EGF family. EGF has been indicated to effectively inhibit the apoptosis of follicular cells, to promote the proliferation of granulosa cells and the maturation of oocytes, and to induce ovulation process via binding to epidermal growth factor receptor (EGFR). However, little is known about the distribution and expression of EGF and EGFR in cattle ovary especially during oestrous cycle. In this study, the localization and expression rule of EGF and EGFR in cattle ovaries of follicular phase and luteal phase at different time points in oestrous cycle were investigated by using IHC and real-time qPCR. The results showed that EGF and EGFR in cattle ovary were mainly expressed in granulosa cells, cumulus cells, oocytes, zona pellucida, follicular fluid and theca folliculi externa of follicles. The protein and mRNA expression of EGF/EGFR in follicles changed regularly with the follicular growth wave both in follicular and in luteal phase ovaries. In follicular phase ovaries, the protein expression of EGF and EGFR was higher in antral follicles than that of those in other follicles during follicular growth stage, and the mRNA expression of EGFR was also increased in stage of dominant follicle selection. However, in luteal phase ovaries, the growth of follicles was impeded during corpus luteum development under the action of progesterone secreted by granular lutein cell. The mRNA and protein expressions of EGF and EGFR in ovarian follicles during oestrous cycle indicate that they play a role in promoting follicular development in follicular growth waves and mediating the selection process of dominant follicles.     

农药市场常见违法行为分析与建议

本文对四川省近5年立案查处的农药市场违法案件进行整理,对案例反映出的农药市场常见违法行为进行归类分析,并提出了相应的监管建议,试图给农药市场监管工作提供参考。     

The mechanical roles of the clasping leaf sheath in cereals: Two case studies from oat and wheat plants

Stem lodging is a common problem in cereal crop production and a main constraint for grain yield improvement. The leaf sheath that surrounds and protects the hollow internodes of stem could provide the plants with a great physical support. However, this biomechanical function has been ignored for several decades in cereal crops. This study aimed to examine the biomechanical properties of basal stem internodes and lodging susceptibility of the whole plants with or without the clasping leaf sheath in wheat (Triticum aestivum L.) and oat (Avena sativa L.) among different genotypes and agronomic practices (including planting densities and nitrogen application rates). The main objective was to quantify the mechanical role of the leaf sheath in oat and wheat crops by a “safety factor” method. On average, the leaf sheath contributed 40%, 68% and 38% of the overall stem bending strength, flexural rigidity and safety factor, in oat, while it accounted for 11%, 24% and 10%, respectively, in wheat plants. The significant contribution of the leaf sheath is due to its vital role in enlarging the peripheral position (i.e., second moment of area) and stiffness (i.e., Young's modulus). The contribution ratios (%) were found to be higher in oat than in wheat plants, due to the greater mass density of leaf sheath and more proficient/prevailing stay-green capability in oat genotypes. This study emphasizes the important mechanical role of clasping leaf sheath on stem internodes of cereals and indicates that the stay-green trait of the leaf sheath can be exploited to design appropriate varieties with improved lodging resistance and great yield potential.     

沼气池热传递过程研究进展

温度是沼气工程高效运行的关键,沼气发酵不仅要维持适宜的温度,还须保证温度的稳定性。为此,对沼气池热传递过程的相关研究进行分析介绍,主要包括沼气池发酵液温度的影响因素、发酵系统热流损失、增温方式和热传递模型研究,并指出增温方式的选择应建立在正确的热过程分析基础上,建议进一步改进优化热传递模型,更好地指导沼气工程实施。