多花黑麦草品种比较试验

通过对现行生产中常用的4个多花黑麦草品种在昆明地区的物候期、株高、草产量、生长率、净同化率等指标的规定表明,在生长初期,特高的生产性能比其余3个品种都好,但生长一段时间后,邦德的生产性能明显超过特高(P<0.05),抗锈王略高于特高(P>0.05),旺饲的生产性能最差(P<0.05)。因此,邦德是一个在生产中值得推广应用的品种。     

长期施肥条件下菜田—蔬菜生态系统变化的研究( Ⅳ) 蔬菜生态系统的变化

 以2002 年设施番茄栽培为代表计算其N、P、K投入量与携出量之间的表观平衡状态, 其结果基本上和14.5 年后的土壤实测值与设施栽培本底值之间纵向比较的增长关系一致, 前者只能说明系统养分变化的趋势, 后者才是实际的养分盈亏状态, 养分盈亏主要取决于有机肥的施用与养分元素的供给。5个代表性处理模拟了蔬菜施肥的不同现状, 从土壤肥力及产量等方面的变化真实反映出各自的系统变化及发展趋势, 在本试验条件下以ANK施肥下的系统最优。对有机肥施用、化学肥料的配施以及测土施肥等问题进行了探讨。     

温度对GF43李离体保存中老化作用的影响

 研究了不同温度对GF₄₃李( ^{_{Prunus domestica}} L. ) 试管苗生长及老化过程的影响。结果表明在16 ℃保存条件下GF₄₃试管苗的营养生长缓慢, 8 ℃保存GF₄₃试管苗的营养生长极缓慢, SOD、CAT 和POD 等保护酶系统的活性维持较高水平, 体内O₂ 自由基、丙二醛(MDA) 含量较低, 细胞膜结构相对稳定, 从而延缓了试管苗的衰老, 延长了两次继代之间的时间, 对试管苗的保存十分有利。     

Functional heterogeneity in resources within landscapes and herbivore population dynamics

Large mammalian herbivores are notorious for their propensity towards population irruptions and crashes, yet many herbivore populations remain relatively stable. I explore how resource heterogeneity within landscapes dampens population instability, using a metaphysiological modelling approach considering patch state distributions. Resource heterogeneity is functionally stabilizing through spreading consumption away from preferred resources before these become critically depleted. Lower-quality resources act as a buffer against starvation during critical periods of the seasonal cycle. Enriching resource quality is destabilizing, even if patch diversity is maintained, because food quantity then becomes the limitation. The potential consequences of landscape fragmentation are explored using the Serengeti ecosystem, characterised by broadscale resource gradients, as a hypothetical example. Further insights provided by the model are illustrated with specific examples concerning the effects of patch scales and waterpoint distribution. A metaphysiological modelling approach enables the basic consequences of landscape heterogeneity to be distinguished from further effects that may arise from specific patch scales and configurations, without the distracting detail of spatially explicit models.     

噻二唑基-3-哒嗪酮类化合物的合成及生物活性

将取代的二酰基肼环合后,得到中间体2-芳基-5-氯甲基-1,3,4-噻二唑,然后与2-叔丁基-4-氯-5-羟基-3(2H)-哒嗪酮反应,合成了8个未见文献报道的含噻二唑基哒嗪酮类化合物,其化学结构经1H NMR、高分辩质谱和元素分析确认。生物活性测试结果表明,部分化合物对粘虫P.separate W.有较好的抑制生长活性,其中化合物 3b 的EC50值为21 mg/L。     

Validation of the specificity and sensitivity of species-specific primers that provide a reliable molecular diagnostic for <Emphasis Type="Italic">Xiphinema diversicaudatum</Emphasis>, <Emphasis Type="Italic">X. index</Emphasis> and <Emphasis Type="Italic">X. vuittenezi</Emphasis>

Xiphinema diversicaudatum and X. index are vector nematode species of economic importance in viticulture regions as they can transmit Arabis Mosaic, Grapevine Fanleaf and Strawberry Latent Ringspot viruses to grapevine. Wang et al. (2003) designed species-specific diagnostic primers from ribosomal genes for both these vector species as well as a vector and a non-vector species X. italiae and X. vuittenezi, respectively. Our study aimed to confirm the specificity and determine the sensitivity and reliability of the primers for the two vector species, X. diversicaudatumand X. indexwhen challenged with closely related longidorid species and general nematode communities typical of vineyard soil. With one exception, no PCR product was observed when the primers were tested against six Longidorus, one Paralongidorus and one Xiphinema non-target species. Occasionally (three out of eight replicate PCR reactions) a weak PCR product was noted when primers for X. index were tested with L. elongatus. Furthermore, when challenged with a range of non-target nematode species comprising the nematode community typical of viticulture soil, no PCR product was amplified. An experimental dilution series of extracted DNA rigorously demonstrated that DNA from an equivalent single specimen of the target virus-vector species, X. diversicaudatum and/or X. index, could be detected amongst 1000 equivalent non-targetX. vuittenezi. Also, extracted DNA from an equivalent single target specimen was detected when added to DNA extracted from the overall soil nematode community. The primers were assessed further by using serial mixtures of actual nematodes rather than extracted DNA to simulate field soil. Using this method, a single target nematode could be detected amongst 200 non-target specimens. Given their specificity, sensitivity and reliability, it appears that these diagnostic primers will be of great benefit to phytosanitary/quarantine services related to the viticulture industry.     

PRRS ELISA试剂盒检测猪繁殖与呼吸综合征病毒抗体的应用

利用重组杆状病毒表达的PRRSV核衣壳蛋白作抗原制成ELISA诊断试剂盒，检测人工感染PRRSV猪血清、疫苗免疫抗体和田间血清，并与IDEXX公司生产的试剂盒进行比较。结果表明，该试剂盒在PRRSV感染后8天内就可检出感染性抗体，而用IDEXX公司生产的试剂盒在感染后的18天才检测到感染性抗体，对弱毒疫苗的免疫检测也基本能反映出疫苗的免疫应答状况。对华东地区PRRSV流行病学调查结果表明，PRRSV在国内普遍存在，同时也证明研制的试剂盒，是客观科学调查我国PRRS流行情较理想的检测工具。     

两种一步法RNA提取试剂的比较

RNA的提取在生物医学研究和临床检测上应用广泛。本文分别用进口Invitrogen公司生产的以及我们自己研制的一步法RNA提取试剂，提取大肠杆菌RNA、鸡肌肉组织RNA和尿囊液RNA，通过核酸电泳和荧光定量RT-PCR进行比较。结果表明用我们自己研制的和进口的试剂提取的RNA都不含有DNA；这些RNA都可以作为模板进行RT-PCR检测，并且在数量上相互之间没有明显差异。说明我们自己研制的一步法RNA提取试剂可以取代进口试剂。此外，本文还讨论了此类试剂一些评定方法。     

牛初乳中活性物质IgG含量分析

通过对产犊后前四天内牛初乳活性物质(IgG)含量的检测，分析牛初乳中活性物质的变化规律及冻结、巴氏杀菌对其影响。     

微量元素氨基酸螯合物在养鸡生产中的应用

微量元素氨基酸螯合物是微量元素添加剂更新换代的优良产品,应用前景广阔。文章概述了微量元素氨基酸螯合物的营养特性、代谢机制、添加方式及其在养鸡生产中的应用。