抢抓机遇加快农机化发展步伐

从农机化发展项目、跨区作业、水稻机插、安全监理、技术推广、农机宣传等方面，全面地介绍了连云港市在2003年听取得的成绩及为抗击“非典”等不利因素所采取的措施。     

猪肺炎支原体巢式PCR诊断方法的建立及应用

为建立一种快速诊断猪肺炎支原体病原的方法,根据GenBank上登录的Mhp基因组序列,在保守区基因内部设计合成2对引物,经过PCR反应条件的优化,建立了检测猪肺炎支原体的巢式PCR方法。结果表明,该方法对鸡毒支原体、猪鼻支原体、猪传染性胸膜肺炎放线杆菌、猪圆环病毒2型、猪伪狂犬病毒的扩增结果均为阴性;第1次扩增的敏感性是10pg,第2次扩增的敏感性是0.1pg,第2次比第1次扩增的敏感性高100倍。巢式PCR检测方法具有特异性强、敏感性高、重复性好等优点,可以在短时间内准确快速的检测出低含量的Mhp病原,为猪肺炎支原体的快速诊断与净化奠定基础。     

塞内加尔达喀尔地区沙丘土壤中有机添加物的荧光表征及去向

The application of organic amendments on soils poor in organic matter (OM) can improve long-term soil fertility, but may also enhance the mineralization of native soil organic matter. Three organic amendments, compost, sewage sludge and horse manure used by urban market gardeners in Dakar, Senegal were analyzed for their OM maturity. Their fate was evaluated in a 45-d agronomic trial in a sandy Arenosol with lettuce. In each case, water-extractable organic matter (WEOM) and humic-like substances (HLS) were isolated from raw amendments and amended soils, and characterized using ultraviolet-visible (UV/Vis) spectroscopy. Results highlighted the general more aromatic character of HLS and WEOM fractions extracted from compost compared to the other two amendments. When applied to soils, however, these differences were not clearly observed. The aromaticity and humification degree of the labile fraction (WEOM) increased with depth in the first 30 cm for all amendments. This indicated the high lixiviation rates that fresh OM underwent in the studied sandy soil. Finally, a statistical analysis of the results was able to discriminate between surface and deeper horizons and between amended- and non-amended soil samples. Spectroscopic indices showed indeed strong increase/decrease with depth linked with the mineralization/humification processes that the fresh OM from amendments underwent during the 45 d of the agronomic trial. This study highlights the potential of spectroscopic techniques to study agricultural amendment organic matter fractions and their fate in soils.     

放牧对甘南草地常见植物的生长和繁殖的影响

本文研究了放牧对青藏高原高寒草甸植物群落中主要组分物种的影响。试验选用26种高寒草甸植物群落中常见的主要组分并分为两个功能群,研究这些物种在放牧压力下的生活史对策,分析了这些种的总生物量变化以及繁殖分配的差异。结果表明:放牧对植物群落中主要组分物种的生物量和繁殖分配有影响,这种影响在不同的功能群和物种之间有差异,对个别物种的影响变化和大多数物种的变化是相反的,但总体的变化趋势是个体总生物量减小,繁殖分配增加。     

班玛藏茶与云南普洱茶中咖啡因含量对比分析

[目的]测定青海班玛藏茶和云南普洱茶茶叶中的咖啡因含量。[方法]采用索氏抽提法提取咖啡因,并对提取出的咖啡因含量进行粗略评价。[结果]班玛藏茶平均回收率为36.3%,咖啡因总量极少(0.000 7 g);云南普洱茶平均回收率为34.3%,咖啡因总量为0.207 5 g。[结论]不同生境的茶叶咖啡因含量各不相同。     

黄南州欧拉型藏羊与小尾寒羊杂交效果分析

2003年,青海省黄南州从山东引进小尾寒羊,与当地欧拉型藏羊杂交,并对杂种羊的产肉性能和生产性能等进行了研究分析。结果表明,杂种羊的繁殖性能和产肉性能都得到了提高,说明山东小尾寒羊与当地欧拉型藏羊杂交后代能取得良好的经济和社会效益,适合推广。