AcNPV在甜菜夜蛾增殖后的分离提纯及观察

报道了苜蓿银纹夜蛾核型多角体病毒（ＡｃＮＰＶ）在甜菜夜蛾增殖后进行的病毒分离、纯化方法,通过超薄切片及电镜进行了病毒超微结构及组织病理的初步观察,并对患病虫体的病征进行了观察。     

南京市粳稻品种优良种性的研究

作物品种的优良种性是实现其“高产、优质、高效益”的内因和基础。适宜南京地区大面积推广种植的单季粳（糯）稻优良品种,必须具备丰产性、稳产性、熟期性、优质性四个方面的优良种性。自１９９１年以来引进了２０多个粳、糯稻新品种和新品系,在校内外农科教结合基地进行了观察试验、示范对比。对其中优良种性表现比较突出的杂交中粳稻２０４Ａ／轮回４２２、迟熟中粳９６－１９、早熟晚粳９４５７８和迟熟中粳糯９５２２５等４个品系作了较为细致地研究。初步认定：这些粳稻新品系通过进一步扩大试验、示范和推广,可以填补全市水稻生产中的高产优质新品种的空白,进而成为优良粳稻的接班和当家品种。     

氨氮对凡纳滨对虾稚虾的急性毒性作用

实验研究了氨氮对体长3．2cm、体质量0．356g（n=10）与体长1．6cm、体质量0．036g（n=15）两种规格凡纳滨对虾（Litopenaeus vannamei）稚虾的急性毒性效应。血氨和碱性磷酸酶活性的测定结果显示,血氨随氨氮浓度的升高而升高,碱性磷酸酶（AKP）活性随氨氮的升高而下降。急性毒性实验结果表明,体长3．2cm稚虾的游离态氨24hLG。为2．068mg／L、48hLC5。为1．654mg／L、96hLG。为1．395mg／L,生存安全浓度sc为0．3969mg／L;体长1．6em稚虾的游离态氨24hLGo为1．577mg／L、48hLG0为1．042mg／L、96hL氏为1．012mg／L,生存安全浓度Sc为0．2065mg／L。     

蚜茧蜂对不同味源的选择性

用“Ｙ”型管嗅觉仪（定向选择）和培养皿（自由选择）法,观测了蚜茧蜂（Ａｐｈｉｄｉｕｓｓｐ．）对茶蚜危害的和非危害的茶树新梢及其不同部位、新梢提取物、茶蚜蜜露和几种非寄主植物材料的定向和选择行为。结果表明,只有茶蚜危害的茶树新梢（包括其不同部位）和茶蚜蜜露对蚜茧蜂有显著的引诱力,表现在蚜茧蜂对这些部位的搜索、停留、触角敲打和产卵管刺探等次数和时间明显增加,并且嗜食蜜露,而非危害的茶树相应部位和非寄主植物（如月季、小叶黄杨）则无明显的引诱作用。     

Analysis of gene cassettes of streptomycin-spectinomycin resistance of Hungarian Salmonella enterica serotype Typhimurium strains

By PCR using the ant(3")-Ia primer pair the aadA gene was detected in 34 streptomycin- and spectinomycin-resistant Salmonella enterica serotype Typhimurium strains. Out of them 12 belonged to DT104 and 22 to non-DT104 phage type. Using different primer combinations it was demonstrated that this gene was integron-associated in all cases: in the DT104 strains it was generally contained by a 1 kb integron while in the majority of the non-DT104 strains by a 2.05 kb (less often by a 1.9 or 1 kb) integron. In the case of integrons carrying multiple cassettes the cassette containing the aadA gene was located closer to the 3' end of the integron. The aadA genes of DT104 and non-DT104 strains were different: in the former group the aadA2 gene, while in the latter group (constituted by strains of five different phages types as well as unclassifiable and untypable strains) the aadA1 gene could be identified. The RH50/RH51 primer pair described by Collis and Hall (1992) proved to be suitable for rapid discrimination between the aadA1 and aadA2 genes on the basis that the RH51 primer bound exclusively to the aadA2 gene.     

低温高湿地区半细毛含脂率与羊毛品质的关系研究

采集云南低温高湿地区永善马楠种羊场两周岁健康半细毛母羊的毛样品４８个，分析了该地区半细羊毛污毛含脂率与羊毛品质之间的关系。结果显示：（１）此区半细毛的原毛含脂率为（１４６±１１２）％，高于我国干冷地区同类羊的原毛含脂率；（２）原毛含脂率与羊毛绝对强度呈正相关（ｒ＝０２８），与羊毛洁白度呈强的负相关（ｒ＝－０４８）；说明原毛含脂的多少确与羊毛强度有关，含脂越高，强度越大；但由于含脂率与羊毛洁白度为较强的负相关，含脂越高，洁白度越差，由此可见，半细毛中确定适宜的原毛含脂率是保证羊毛品质的重要指标之一；（３）羊毛的ｐＨ值与原毛含脂率呈正相关（ｒ＝０１９），与羊毛洁白度呈强的负相关（ｒ＝－０５５）；因而控制羊毛ｐＨ值在适宜范围内有利于改进羊毛的品质。     

禽多杀巴氏杆菌的交叉保护性研究

经差速和蔗糖密度梯度离心，从Ｐ１０５９感染鸡的血液中提取巴氏杆菌。每羽鸡可提取较纯的菌液约１０ｍｌ，含菌量在１００亿／ｍｌ以上。该菌液灭活后免疫鸡，用异型菌Ｃ４８１交叉攻毒，结果与肝组织苗免疫的一样，均具有５０％的保护率，而Ｐ１０５９攻毒耐过鸡则全保护。结果证明，体内繁殖的巴氏杆菌具有交叉保护性，而体外培养菌则没有。     

中国华东地区猪生殖-呼吸道综合征病毒(S_1株)ORF_(5～7)基因特征研究

本研究对我国华东地区猪生殖和呼吸综合征病毒（ＰＲＲＳＶ）分离株Ｓ１主要结构蛋白基因（ＯＲＦ５～７）进行了ＰＣＲ扩增和ＤＮＡ测序分析。结果表明，长度为１５２０ｂｐＤＮＡ序列含有３个阅读框ＯＲＦｓ，即ＯＲＦ５、ＯＲＦ６和ＯＲＦ７，ＯＲＦ５和ＯＲＦ６及ＯＲＦ６和ＯＲＦ７间有部分碱基重叠，且与欧洲型和美洲型ＰＲＲＳＶ相似。ＯＲＦｓ推导的氨基酸序列与美国ＶＲ２３３２和欧洲ＬＶ毒株同源性分析为９９％～１００％和５９％～７８％。ＯＲＦｓ预测的蛋白质分子量、等电点、糖基化位点、亲水性分布图及跨膜螺旋区与ＶＲ２３３２毒株相似。     

Histological and histochemical changes in the digestive tract of white sturgeon larvae during ontogeny

Ontogenetic changes in digestive tract histology and digestive enzyme histochemistry were investigated 11 to 36 days post-hatch in white sturgeon Acipenser transmontanus larvae. From initiation of exogenous feeding (12 days post-hatch), larvae were fed a commercial salmonid diet for the ensuing 24 days. The digestive system of white sturgeon displayed a high degree of morphologic organization and functionality at the onset of exogenous feeding. An enhancement of digestive capacities occurred with transition to active feeding. On day 2 of feeding, there was a clear increase of alkaline phosphatase, aminopeptidase M, dipeptidyl peptidase IV, and -glutamyl transpeptidase activity in the brush border of the spiral intestine. This strong activity is an apparent confirmation of the importance of this segment of the intestine for protein digestion and nutrient absorption. The functional development of the pyloric intestine occurred on day 4 and was concomitant with an increase in the activity of brush border and cytoplasmic enzymes such as acetylcholinesterase, dipeptidyl peptidase II, - and -galactosidases. The absence of acetylcholinesterase, lactase, nonspecific esterase, and weak activity of exopeptidases and alkaline phosphatase in the anterior intestine suggests that this segment of the intestine may be less important in nutrient absorption than the pyloric and spiral intestines. The observed quantitative and qualitative differences in enzyme activity along the intestine indicate a high degree of specialization of each segment for specific digestive and absorptive processes.     

Growth of Daphnia magna on urban wastewaters tertiarily treated with Scenedesmus sp.

The productivity and composition of Daphnia magna were measured for high density populations grown in 5-litre flow-through tanks supplied with a tertiary effluent. This effluent was urban secondary wastewaters biologically treated with intensive cultures of a microalga Scenedesmus sp.Three daily feeding rates (575, 1150, 1750 mg dry weight algae day^?1 tank^?1), obtained by adjusting the flow of a tertiary effluent containing 115 mg dry weight of algae litre^?1, allowed average productions of 0·9, 1·6 and 2·6 g of Daphnia (wet basis) litre^?1 week^?1 which were proportional to the rations. When the flow of tertiary effluent was increased to 40 litres day^?1 tank^?1 (ad libitum), the average yield rose to 3·6 g of daphnids (wet basis) litre^?1 week^?1. The maximum population reached 48 000 individuals litre^?1. The daphnid/algae evergy conversion ratio was 0·4. Algae were removed by Daphnia at a maximum efficiency of 95%. The composition of Daphnia biomasses was 59·5% protein, 9·5% fat and 5·6% carbohydrate on a dry weight basis. No deficiencies in methionine and linolenic acid were noted.Results indicated the remarkable potential of urban wastewaters for the production of protein and the high productivity of Daphnia magna.