螟黄赤眼蜂繁蜂质量监测与评价

对以柞蚕卵为中间寄主的螟黄赤眼蜂的繁蜂质量进行了监测和评价。结果表明，随着繁蜂代数的增加，螟黄赤眼蜂子代蜂的繁殖能力明显下降。在柞蚕卵上连续繁殖25代后，其寄生率、单卵蜂量和羽化率分别下降44．08％、45．00％和65．72％，子代蜂寄生率和单卵蜂量平均每代衰减为2．0％，而羽化率下降3．0％。其发育历期延长72h。子代蜂性比（雌：雄）下降幅度不大，在8．25～9．59：1。     

抑菌圈-定殖力双重测定法筛选青枯病生防细菌

 本研究首先用平皿抑菌圈法筛选出55个拮抗青枯菌的细菌菌株,将番茄幼苗在各菌菌悬液中浸根12h后栽种于温室未灭菌的土壤中,结果发现,有22个菌株在幼苗根部的定殖能力较强(终定殖密度大于104 cfu/g根),其中革兰氏阴性土壤细菌占同类菌的86.3%,革兰氏阳性土壤细菌占同类菌的13.0%,10个无致病力产细菌素的青枯菌菌株在根部的终定殖密度均低于104 cfu/g根,其定殖能力弱于致病青枯菌。有17个拮抗菌菌株在番茄幼苗根部的定殖密度超过所有致病菌。温室生防结果证明,抑菌圈-定殖力双重测定法对于筛选生防菌株是一种行之有效的方法。     

Components of resistance to late blight (Phytophthora infestans) in eight South AmericanSolanum species

Four components of partial resistance toPhytophthora infestans were measured after inoculation in the greenhouse and in the field ofSolanum arnezii x hondelmannii, S. berthaultii, S. circaeifolium, S. leptophyes, S. microdontum, S. sparsipilum, S. sucrense andS. vernei, and four hybrid progenies ofS. microdontum withS. tuberosum. The four components were infection efficiency, lesion growth rate, generation time and sporulation capacity. The results were compared with resistance ratings derived from field experiments, and with observations made on the potato cultivars Bintje, Bildstar, Libertas and Pimpernel. Genetic variation for all components was found, while the relative importance of the components of partial resistance appeared to vary between the species. InS. microdontum, generation time, infection efficiency and lesion growth rate, and inS. tuberosum infection efficiency, lesion growth rate and sporulation capacity appeared positively associated, but in other species no such association was found. A strong hypersensitive reaction, the expression of which appeared to depend on environmental conditions, was found inS. microdontum. ForS. berthaultii, infection efficiency appeared to be the main resistance component.Abbreviations ADPC area under the disease progress curve - IE infection efficiency - LGR lesion growth rate - GT generation time - SC sporulation capacity     

兴安落叶松播种苗施肥效应和障碍

在塔河林业局中心苗圃对兴安落叶松Ｌａｒｉｘ ｇｍｅｌｉｎｉ（ＲｕＰｒ．）播种苗进行了施肥效应和施肥障碍研究。结果表明，以有机中添加适量的无机肥料的为基础，并在苗木不同物候期中追施适当比例尿素和二胺对促进苗木高征稿攻地径生长效果最佳，而单独施基肥、最有利于促进苗木侧根的生长；以施有基肥和追施高水平的二胺对苗木茎；根及个体总干物质积累效应显著；综合试验结果，影响苗木生长效应的施肥主导因子顺序为二胺、基     

沙子岭猪肥育性能与肉质特性研究

本试验选择16头沙子岭纯种仔猪,随机分成二组,分别饲喂不同能量、蛋白水平的日粮,探讨营养水平对沙子岭猪肥育性能与胴体品质性状的影响。结果表明:低水平和高水平组日增重分别为411.38g、445.75g,差异不显著(P>0.05);饲料报酬分别为4.82∶1、4.48∶1;每公斤增重饲料成本分别为6.60元、6.54元;胴体瘦肉率分别为44.59%、40.82%,差异不显著(P>0.05)。与国内地方猪种比较,沙子岭猪具有生长速度较快、屠宰率较高、眼肌面积较大、背膘较薄、瘦肉率较高的特点。     

Effects on animal performance and sward composition of mixed and sequential grazing of permanent pasture by cattle and sheep

Previous experiments have shown that mixed or conjoint grazing, when two or more animal species are grazed together, can lead to improved performance of one or more of the species and a higher total output per unit area. Sequential grazing systems, when different animal species graze an area in succession, also have the potential to improve productivity. This experiment directly compared these two approaches for integrating the grazing of cattle and sheep when pastured on improved permanent pasture. Four treatments were compared: 1) sheep only from May to October (S/S); 2) cattle only from May to July followed by sheep only from August to October (C/S); 3) cattle and sheep from May to July, sheep only for the rest of the growing season (C + S/S); and 4) cattle and sheep from May to October (C + S/C + S). Each treatment was replicated three times. From May until weaning at the end of July the plots were grazed by steers and ewes and lambs, and from weaning until October by steers and lambs. Sward heights were maintained at 6 cm using a “put and take” stocking system. Animal performance and sward composition data were collected during three growing seasons, 2001–2003. During the pre-weaning period lambs grazing plots which were grazed only by sheep had significantly poorer growth rates than those grazing plots where there was mixed grazing. Lambs grazing the sheep only plots also had lower liveweight gain during the post-weaning period, with the highest growth rates being recorded on the C + S/C + S treatment. Carrying capacity and total liveweight gain per unit area post-weaning were also consistently higher for the C + S/C + S treatment, while carrying capacity pre-weaning was highest for the C/S treatment. Measurements of clover content in the grazed horizon and botanical separation of material from quadrat cuts indicated that even under relatively controlled conditions choice of grazing system can influence sward composition. However, there was no clear link between any single sward change and the growth of the animals, indicating that the improved performance of cattle and sheep under mixed grazing is the result of a combination of factors, rather than a response to a particular sward parameter.     

影响山羊胚胎冷冻效果因素的研究

分别用浓度为1.5 mol/L的乙二醇(EG),1.5 mol/L 1,2-丙二醇(PROH)和1.5 mol/L甘油为冷冻保护液对山羊胚胎进行常规冷冻保存,结果三者对山羊胚胎的冷冻保护效果无显著差异,其中以1.5 mol/L EG的冷冻保护效果为佳。以EFS40为玻璃化液对山羊胚胎进行细管法和OPS法玻璃化冷冻,其结果与常规冷冻间差异不显著,表明常规冷冻法、玻璃化细管法和OPS法均可用于山羊胚胎的冷冻保存。采用25℃和37℃水浴对常规冷冻和玻璃化冷冻后的山羊胚胎进行解冻,从解冻后的发育效果看,二者间无显著差异,但37℃水浴解冻后的胚胎发育效果略好于25℃。还比较了玻璃化液EFS40中添加FCS和BSA后与不添加其他成分的EFS40对胚胎冷冻保护效果的影响,结果表明添加BSA的EFS40的冷冻保护效果显著地高于不添加其他成分的EFS40,但与添加FCS的EFS40间不存在统计学上的差异。     

金针菇单核出菇与子实体颜色

利用原生质体单核化技术从8个金针菇栽培菌株中获得13种不同的黄色单核体菌株和3种白色单核体菌株;单核体出菇实验结果表明,5种黄色单核体和2种白色单核体可以形成单核子实体,其中,黄色单核子实体间在菌柄、菌盖颜色方面差异较大,而且部分单核子实体本身的菌盖和菌柄的颜色也具有明显的差异,说明控制子实体黄颜色的因子存在复等位因子。     

冷冻方法和冷冻保护液对山羊卵母细胞发育的影响

比较了不同冷冻方法和冷冻保护液对山羊卵母细胞冷冻-解冻后体外受精和激活后的发育效果.结果表明,开放式拉长塑料细管(OPS)法的效果好于玻璃化细管法和常规冷冻法;在OPS法中,20%EG 20%DMSO对卵母细胞的冷冻保护效果好于EDFS40,而在玻璃化细管法冷冻中,则是EDFS40好于20%EG 20%DMSO.对于常规冷冻法而言,则是1.5mol/L EG的冷冻效果好于1.5mol/L PROH.