关于贸易便利化的议题最早是在1996年新加坡部长会议上提出的,到2001年多哈部长级会议,该会议决定在对贸易便利化的谈判模式达成了一致的基础上进行谈判.在2004年7月份,明确以"贸易便利化谈判模式"作为基础进而启动贸易比化谈判,同10月份正式启动此次谈判,在2013年结束了这长达13年的谈判.

为了给白三叶草的选育和资源利用提供理论依据,采用聚丙烯酰胺凝胶电泳的方法,对来自不同地区的16份白三叶草(Trifolium repens L.)种质资源进行酯酶(EST)和过氧化物酶(POD)同工酶检测,并对检测到的5个等位酶位点的图谱进行分析,再根据各种质资源间遗传相似度及聚类结果进行分析.结果表明:白三叶草各种质资源间有较高的遗传多样性;16份白三叶草种质资源在相似系数为0.71的水平上可以聚为三类,大部分地理区域临近的种质材料首先聚在一起.说明他们有较近的亲缘关系.

矮脚鸡为鸡中的独特品种,脚胫比常规鸡脚胫短1/2～1/3.一般鸡的脚胫长在10 cm以上,而矮脚鸡仅5～7cm长.由于胫短而导致身矮,故矮脚鸡的特征特别显示脚短身矮,性情温驯而且耗料少,是笼养或规模化养殖的特选鸡种.

According to the studies on root system of annual ryegrass in the condition of organic fertilizer,the results are as following:Root system of annual ryegrass are mainly distributed in 0~20 cm layer below the surface of soil,which amounted for 86.43%~93.76% in weight,and they are more mainly distributed in 0~10 cm,which amounted for 73.86%～88.06%。The root system growth rate is affected by nature factors and themselves′ factors.Lantiantang,Jiewei and Tegao grew fastest at the third times.Jiewei grew faster than the others at seeding stage,after that time,it grew obviously slower than LanTianTang and Tegao.In all,Tegao grew best at the seeding quantity of 3.00 g/m2.

文章主要对近些年来国内外专家、学者对多花黑麦草生物学特性、生理、细胞形态及分子遗传学、营养价值等方面的研究以及所取得的成果进行了概括与分析。

The variation patterns of relative water content,membrane permeability,praline content and chlorophyll content in white clover leaf blade under high temperature stress were studied.The results indicated that the membrane permeability and praline content were graduall yincreased at 25 ℃ to 35 ℃ for 0.5hours,on the contrast,the relative water content and chlorophyll content decreased gradually,but the variation range was not wide.However,the variation was great while treated under the high temperature more than 45 ℃.Compared with those under the normal temperature 25 ℃,the membrane permeability and praline content increased by 50.62%and 59.89% on average respectively when the temperature increased every 5 ℃.In consequence,the relative Water content and the chlorophyll content decreased by 34.22% and 4.61%respectively.Under the experimental conditions,Whire clover can adapt to 35 ℃,and the critical temperature was ranged from 40~45 ℃,the fatal temperature was 50 ℃.

贵州喀斯特地区退耕还林后,耕地大面积减少。免耕能省工、节时、高产、高效、保持水土。在退耕林下应用免耕技术播种牧草,可最大限度地节省人力、物力,对研究在贵州这种特殊地形下退耕林地的应用有一定意义。

在贵州大学实验基地,利用冬闲田研究了不同施肥水平对科牧70、光叶紫花苕、一年生黑麦草、燕麦草的鲜草产量、干物质以及干物质中的营养成分影响。结果表明:随着施肥量的增加,牧草鲜草产量和干物质明显增加;总干物质中营养成分从高到低依次是一年生黑麦草、光叶紫花苕、燕麦、冬牧70。综合各处理结果,在四种牧草中,最适宜贵州冬闲田种植的是一年生黑麦草。