Identification of feline blood B and T lymphocytes by cell electrophoresis.

The electrokinetic properties of feline blood lymphocytes isolated by centrifugation over Ficoll-Isopaque gradient were investigated. A biphasic electrophoretic mobility (EPM) distribution was regularly observed with a low-mobility (LM) population (mean EPM: 0.82) accounting for 32% of blood lymphocytes and a high-mobility (HM) population (mean EPM: 1.09) representing 68% of blood lymphocytes. Following fractionation on nylon-wool columns, lymphocytes with B-cell properties (64% sIg⁺; 9% guinea pig erythrocytes (GPE)-rosette⁺, PHA and Con A unresponsive) were enriched in the adherent fraction and belonged mainly (78%) to the LM population. In contrast, lymphocytes with T properties (5% sIg⁺, 42% GPE-rosette⁺, PHA and Con A responsive) were recovered in the effluent fraction and comprised 84% of HM elements.Thus, in cat blood, LM lymphocytes are likely to represent in majority B cells and HM lymphocytes T cells. This indicates that cell electrophoresis provides an interesting mean for differentiating B and T cells in the cat.     

A method to test wheat leaves for their reactions to inoculation with Septoria species

The construction and application is described of a polystyrol humidity box in which wheat leaves, while continuing to function as parts of living plants, can be tested for their reactions toSeptoria spp. in an atmosphere nearly saturated with water, as is required for successful infection. The method is simple, accurate ans inexpensive.Samenvatting Voor dit doel is een z.g. vochtdoos geconstrueerd (Fig. 1A). Het te toetsen blad wordt daar doorheen geleid en in de doos geïnoculeerd met een druppel conidiën-suspensie van de schimmel. Onder het blad staat wat water in de doos (Fig. 1B). Na afsluiting ontstaat in de doos de hoge luchtvochtigheid van bijna 100% die nodig is voor de infectie. Dit wordt op deze wijze eenvoudig en goedkoop gerealiseerd. De bladeren die zo worden getoetst blijven onbeschadigd functioneren aan de plant. Na enkele dagen kan de doos worden geopend en kan de symptoom-ontwikkeling worden afgewacht en gevolgd (Fig. 3A, 3B en 4). De methode leent zich voor nauwkeurig werk en vereist zeer weinig infectiemateriaal. De Technische en Fysische Dienst voor de Landbouw (TFDL), Wageningen, ontwierp en construeerde een statief voor het gebruik van de vochtdozen in serie (Fig. 2).     

水稻苗田化学除草剂—封闭1号大面积苗田药效示范试验结果

通过多点水稻苗田大面积示范试验结果表明,通化市农科所研制的水稻苗田除草剂“封闭1号”具有除草效果好(90～100％)、安全、使用方便、成本低等特点。1988～1991年,累计推广面积(苗田)达15.6万亩,创造经济效益150万元。     

Bacterial diseases of potatoes: from classical phytobacteriology to molecular pathogenicity

Various bacterial pathogens attack potato plants and tubers. These pathogens includeErwinia, Corynebacterium (Clavibacter), Psuedomonas andStreptomyces. Over the past few years there have been significant advances in the molecular biological analysis of several of these pathogens and this is now helping us to understand the major aspects of virulence mechanisms. However, to date, such information is not sufficiently useful to allow us to intervene rationally in these potato diseases, except by the standard practises of good husbandry.     

ONCHOCERCA GUTTUROSA IN Danish cattle. Prevalence, geographic distribution and host-vector relationships.

1. Onchocerca gutturosa is reported in Danish cattle for the first time. Microfilariae were found in 38 (9.4%) of 406 cows that were 2 years or older.
2. Microfilariae were not randomly distributed throughout the skin but were concentrated in the umbilical area.
3. No difference in prevalence was observed between breeds of cattle.
4. Most of the infected cows had grazed on fields close to streams that contained Simulium ornatum, the vector of O. gutturosa.
5. Differences in preferred biting sites of S. ornatum from cow to cow were correlated with the arrangement of hair.

     

自由放养下绵羊的营养参数

根据绵羊的营养参数和饲养标准,结合日增重水平,计算了不同日增重水平对应的体重月平均动态及其所对应的粗蛋白日需要量和代谢能日需要量。不同日增重水平,达到生长期望所需要的日数不同,日增重水平越高,达到生长期望总所需要的粗蛋白和代谢能越少,但月平均的日需要量越多。自由放养的东北细毛羊当年生羔羊的日增重水平仅相当于舍饲饲养日增重的100g水平,根据代谢能计算,年总需干草340kg,可以作为计算载畜量的基本参数。自由放养情况下,即使能量满足需要,粗蛋白也短缺。当年生羔羊日增重在150￣200g,9￣10月龄内体重达到46￣50kg是北方草地家畜生产的理想目标,通过补饲可以实现。     

茭白肉质茎膨大过程中的糖代谢与激素含量变化

 以单季茭白品种‘蒋墅茭’和双季茭白品种‘葑红早’为试材, 研究了秋季肉质茎膨大过程中物质运转的相关生理生化变化。结果表明, 随着肉质茎鲜质量、干质量快速增加, 非结构性碳水化合物主要成分含量总体上升, 后期出现下降, 蒋墅茭肉质茎中蔗糖含量较高; 糖分转化关键酶活性总体较高,转化酶活性以酸性转化酶较高且呈快速下降, 蒋墅茭的酸性转化酶活性高于葑红早而中性转化酶活性较低;蔗糖合成酶的分解方向活性显著高于合成方向, 且后期维持较高水平, 葑红早的双向活性均高于蒋墅茭;Z + ZR总体含量最高、下降最明显, GA₄ 其次, IAA也呈缓慢下降趋势, GA₃、ABA含量极低, 且各激素均以葑红早高于蒋墅茭。茭白肉质茎干、鲜质量处于快速增长阶段的同时, 而内部生理生化快速下降, 说明茭白肉质茎膨大过程具有特殊性, 并且品种间存在差异。     

以电导法配合Log istic方程确定茶梅‘小玫瑰’的抗寒性

 摘　要: 以不同处理时间、不同低温处理下茶梅‘小玫瑰’叶片的电解质外渗率(REC) 变化作曲线,并结合Logistic方程分别计算茶梅的半致死温度(LT50 ) , 结果发现在低温处理6 h以上, 茶梅叶片的REC均随着处理温度的降低而呈“S”形上升, 由此计算出“S”形拐点对应的温度即为茶梅叶片的LT50 , 其温度值在- 1215℃至- 14℃之间, 这可认为是茶梅抗寒能力的重要指标。关键词:     

番茄不同部位中糖含量和相关酶活性的研究

 试验将番茄光合产物运转途径上叶片(源) 、运输系统以及果实(库) 区分开, 分别测定其糖的组成和含量以及糖代谢相关酶的活性。结果表明: 番茄光合产物运转途径上从“源”到“库”各部位糖的组成和含量不同。叶肉中果糖的含量最高, 蔗糖的含量最低; 中筋中以果糖和葡萄糖为主; 叶柄维管束中葡萄糖含量最高, 蔗糖含量次之, 果糖含量最低。节间和果柄维管束中主要含有蔗糖。果实维管束以及果实内各部位中则主要含有葡萄糖和果糖, 且两者含量无显著差异, 蔗糖含量很低。萼片中葡萄糖含量最高, 蔗糖含量最低; 果蒂中3种糖含量均较高且无显著差异。番茄叶肉及光合产物运转组织中转化酶活性很低, 而在库器官的非维管组织中转化酶活性较高。果蒂中的蔗糖合成酶( SS) 活性最高, 其次是叶肉和运转组织, 果实内各部位中SS活性较低。在合成蔗糖的器官—叶肉中, 有较高的蔗糖磷酸合成酶( SPS) 活性, 运转组织中的SPS活性较叶肉中降低, 但果柄维管束和果实维管束中则表现出较高SPS活性, 果肉、果胶质胎座及心室隔壁中的SPS活性最低。