主要对西藏林芝地区某牛场不明原因牛猝死进行研究.通过病死牛病料组织触片镜检和分离培养皆未发现细菌；乳胶凝集试验检查血清为伪狂犬病病毒(PRV)抗体阳性；以脑组织制备DNA模板进行PCR,扩增到特异性的PRV DNA片段；对健康成年兔接种病牛脑、肺等病料,表现典型的伪狂犬病症状.综合流行病学、细菌学、血清学、分子生物学和动物试验结果,确诊为牛伪狂犬病.

Germination process of 4 different spring barley varieties were tested under different levels of water stress.Results indicated that: (1) Seed germinations of all varieties were suppressed to some degrees under water stress.Germination suppression rate of all 4 varieties were 16%-52% and 4%-50% under severe and light water stress respectively,among which‘Shekatze 17’variety was the most severely suppressed.(2) Germination rate,germination index and vitality index of all varieties were decreased under water stress.Effect of water stress on germination was highest for‘Zangqing 320’variety and followed by‘Maqu 132’,‘Shekatze 17’and‘Zangqing 148’in order.As the water stress was increased,germination speed was decreased obviously and sprouting strength was also obviously week.(3) Water stress was also suppressed the growth of sprouts and roots.As the water stress increased,sensitivity to the suppression was higher for sprouts than for roots.‘Shekatze 17’was the most sensitive to suppression for roots,while‘Zangqing 320’was the most sensitive to suppression for sprouts.Different genotypes of spring barley responded differently to water stress.This indicated that draught tolerance traits of spring barley were different for different genotypes.Among the 4 varieties of spring barley,according to the overall performance of seed germination periods,Zangqing 148 was the best for draught tolerance followed by‘Maqu 132’,‘Zangqing 320’and‘Shekatze 17’.

从高等农业教育在服务农村经济中存在的问题、高等农业教育未来发展的战略等几方面分析了农业高等教育与农村经济发展的关系,指出农业高等教育对农业和农村经济发展的重要作用,农村经济发展要依靠农业高等教育,依靠农业科技的进步和农村劳动者素质的提高。

1 材料与方法 1.1 时间与地点时间为2003年8月-2004年10月.地点在西藏林芝地区林芝县,是西藏河谷型绵羊的中心产区之一,为较暖湿的亚热带气候.平均海拔2 900 m,降水量600～900mm,蒸发量为1 200～2 000 mm,日照时间长,无霜期长.主要作物有小麦、青稞、油菜等.

用肉用品种无角道赛特羊和西藏绵羊杂交一代公羔及西藏绵羊各10只,进行育肥试验。结果表明,试验组比对照组平均日增重高43.26g(P<0.01),屠宰率、净肉率、瘦肉重分别高出6.78%、7。11%、22。91%,均差异极显著(P<0.01)。说明无角道赛特羊在西藏林芝地区是杂交改良和培育肉用新品种羊较理想的父本。

肉羊改良与育肥技术就是利用各种杂交的方法,以本地肉羊为母本,引进优良肉用品种为父本进行杂交,培育的商品肉羊既保留了本地肉羊粗放、适应性强的特点,又有外来优良品种生长快、产肉多、肉质好的优点,有利于农民致富奔小康.本试验通过引进无角道赛特公羊×西藏绵羊母羊F1代公羔的育肥试验,了解和掌握无角道赛特羊与西藏绵羊杂交一代在完全放牧条件下的生长发育情况,以便为今后西藏肉羊生产提供理论依据.