内蒙古苏尼特右旗草原土壤营养元素有效态含量分析

本研究选择内蒙古苏尼特右旗天然草场主要6个草场类,8个草场型,分析了0~30 cm土壤营养元素(全N、P、K、Ca、Mg、S、Fe、Mn、Cu、Zn、B和Mo)有效态含量及与土壤有机质、pH值之间的相互关系。结果表明,1)研究区土壤pH(8.84±0.23),均为碱性土壤;土壤有机质含量与全N含量均较低,平均分别为(9.92±4.65) g/kg和(0.46±0.25) g/kg;营养元素有效态含量积累顺序为:河泛地、湖盆低地盐生草甸草场类>荒漠草原草场区“小针茅+无芒隐子草+葱属”植被型>沙丘植被草场类,河泛地、湖盆低地盐生草甸草场类土壤矿质元素有效态含量显著高于其他草场类。2)土壤富含K元素,B和Mo处于严重缺乏状态;除了河泛地、湖盆低地盐生草甸草场类以外草场类微量元素含量均处于轻度缺乏或缺乏状态。3)土壤pH与土壤N、P、Ca、Mn和Cu元素有效量存在显著负相关性关系;土壤有机质则与土壤N、P、Ca、S、Fe、Mn和Cu元素有效量存在极显著正相关性关系。     

华北驼绒藜替代不同比例粗饲料对苏尼特羊增重及经济效益的影响

试验将驼绒藜按不同精粗比配合成颗粒日粮饲喂苏尼特羊,对比分析驼绒藜日粮与苜蓿日粮、谷草日粮对羊增重的效果。结果表明,华北驼绒藜、苜蓿、谷草铡短粉碎与50%、30%精料混合制成颗粒日粮对绵羊体增重效果最好,日增重可达127 g/d;在荒漠草原区,苜蓿的高价格是限制其推广的主要原因;华北驼绒藜和谷草在30%精料水平下,与同精料水平条件下用苜蓿饲喂绵羊具有相同的增重效果,并可增加纯收入80元/只。     

大麦β 葡聚糖的提取及功能研究进展

大麦是世界上第四大禾谷类作物,其籽粒中的β-葡聚糖是重要的功效成分之一。本文综述了大麦籽粒β-葡聚糖的特性、含量变化和结构特征、提取方法和工艺,以及在大麦饲料、啤酒麦芽、饮料食品、保健医药中的功能研究进展。     

割前摘脱收获机立式离心分离复脱清选装置优化

针对水稻割前摘脱脱出物草谷比低和处理量大的特点,为提高谷物脱出物的处理能力,设计了一种可循环喂入的立式离心分离复脱清选装置并对其进行了响应面优化试验。以喂入速度和螺旋输送器转速为影响因素,以分离率、复脱率和破碎率为试验指标,通过二次正交旋转中心组合试验得到了其性能指标和工作参数的响应曲面模型。利用Design-Expert软件分析各参数对性能指标的交互作用可知,输送器转速对分离率、复脱率和破碎率的影响较大,而喂入速度则较小。通过多目标优化,得到最佳工作参数:输送器转速541.4 r/min、喂入量1.226 kg/s;在该参数组合下的期望结果:分离率为90.4%、复脱率为66.1%、破碎率为0.77%;在该参数组合下的验证性试验结果:分离率为89.4%、复脱率为65.2%、破碎率为0.83%。结果表明立式离心分离复脱清选装置处理效率高,谷物损伤小,能够适应对割前摘脱脱出物的处理要求。     

松嫩平原农情遥感监测系统的设计与实现

利用MATLAB语言进行可视化设计出松嫩平原农情遥感监测系统,客观地对松嫩平原农作物生长状况的历史数据进行评估和实时监控。松嫩平原农情遥感监测系统主要功能为农作物长势监测(NDVI、VCI、MVCI、RMNDVI、RPNDVI)和自动化提取农作物(玉米、水稻、大豆)等松嫩平原重要粮食作物遥感信息,同时对3类地表(湿地、林地、草地)等分类。该监测系统解决了松嫩平原植被遥感信息提取研究中需要处理大量影像数据的问题,为未来研究松嫩平原植被特征变化和规律提供了非常好的技术支持;也可以应用于其他区域和影像数据研究中,具有稳定性好、处理数据速度快、分类精确度高的特点。     

寒地水稻旱直播栽培技术探讨

近年来寒地水稻旱直播面积有扩大趋势,但生产中存在品种选择随意、保苗率低、杂草防治效果差等现象,导致产量不稳。由于技术还不成熟,盲目扩大规模更容易给农民造成较大损失。针对目前寒地水稻旱直播中存在的问题,初步提出了寒地水稻旱直播栽培技术措施,并探讨了生产中存在的问题与解决方法。     

马齿苋ISSR-PCR反应体系与反应条件的优化

[目的]优化马齿苋ISSR-PCR反应体系与反应条件。[方法]以马齿苋为试验材料,采用改良的CTAB法提取总DNA,对ISSRPCR引物进行筛选,同时进行ISSR-PCR反应体系和反应条件的优化,电泳检测ISSR-PCR产物。[结果]8个ISSR引物适合马齿苋的ISSR-PCR分析;最适反应体系为总体系25.0μL,其中2×Taq Platinum PCR Master Mix 12.5μL,10μmol/L引物2.0μL,40 mg/L DNA模板1.0μL,dd H_2O 9.5μL;最适反应条件为94℃预变性360 s;94℃变性60 s,54℃退火60 s,72℃延伸90 s,30次循环;72℃再延伸300 s。[结论]建立了马齿苋ISSR-PCR扩增的最佳反应体系和扩增程序,为进一步研究马齿苋提供基础资料。     

Testing and Identification of Carp Edema Virus Disease in Cultured Koi

An acute infectious diseases occurred in a koi farm in Fangshan district, Beijing, and it resulted in mortalities of more than 50%.The main symptoms of sick koi were gills necrosis, kidney erosion and edema,which were similar to the clinical signs of koi herpes virus disease (KHVD).But PCR tests showed negative results for KHV. For further diagnosis, bacterial cultures, transmission electron microscopy studies, virus isolation and PCR tests were used. Electron microscopic observation revealed pox virus particles having a size of about 200 nm×400 nm in the kidney. 548 and 180 bp fragments were amplified from organs of sick koi by PCR method using specific primers of carp edema virus (CEV). The fragments were sequenced and analysed. The results showed that they were shared 100% nucleotide identity with CEV-H504. All the results indicated that this disease was carp edema virus disease, caused by a kind of pox virus, CEV. This was the first report on the CEV of cultured koi in China.     

养殖锦鲤鲤鱼浮肿病的检测与鉴定

北京房山某锦鲤养殖场锦鲤发生大量死亡,患病锦鲤呈烂鳃、肾脏糜烂、身体浮肿;症状类似锦鲤疱疹病毒（koi herpes virus,KHV）感染,但经PCR检测排除了KHV感染。为进一步确定病原,对发病鱼进行了临床症状观察、病毒分离、细菌分离培养、病鱼组织超薄切片电镜观察和PCR扩增等检测。通过病鱼组织超薄切片电镜观察,在肾脏内可见200 nm×400 nm的痘病毒样颗粒。抽提病毒核酸后,用已知的鲤鱼浮肿病毒（carp edema virus,CEV）的保守序列设计2对引物进行PCR扩增,扩增出548和180 bp片段,测序结果和GenBank公布的CEV H504株序列完全一致。根据发病鱼临床症状和实验室检测结果,最终确定该病为CEV引起的鲤鱼浮肿病。这是在中国首次发现的鲤鱼浮肿病。     

Comparison of wood,fibre and vessel properties of drought-tolerant eucalypts in South Africa§

Three drought-tolerant eucalypt genotypes have been investigated for a broad spectrum of properties to provide a basis for comparison on their suitability for various end-uses. The genotypes included were a Eucalyptus grandis × E. camaldulensis hybrid, E. gomphocephala and E. cladocalyx, selected based on previous studies that indicated good potential to tolerate arid conditions, reasonably good volume growth and straightness of stems. In this study, information was added on differences between species and parts of stems in growth (volume and biomass) and properties of wood (density and stiffness), fibres (dimensions and microfibril angle) and vessels (size and numbers). We found high wood densities and stiffness values for E. cladocalyx and E. gomphcephala, making them suitable for construction wood. Logs from the mid-part of the stem had the best timber properties, as the butt logs showed the highest microfibril angle and lowest wood stiffness due to longitudinal juvenility. Such juvenility was also to some degree observed for wood density and fibre length. The information gained will be especially helpful for selecting species and processing options for small farm and community plantations for producing higher-value products that may be sold to generate much-needed income as well as for local uses, such as fuelwood and charcoal.