鸡新城疫病毒B_(95)株的RT-PCR检测方法研究

本试验设计了一对B95 株的特异引物NDV -P1/P2,探讨了对其进行RT-PCR检测的可行性。结果证明 ,用该引物可以扩增出一条310bp的特异核酸带 ,敏感性为0.0043ng/ul。     

Differences in Wheat Cultivar Response to N Supply. I: Differences in Grain Yield Formation

Two-year field trials with winter wheat cultivars Batis and Toronto were conducted in Southern Bavaria, Germany, to investigate the possible causes of cultivar differences in response to N supply varying in total amount and time of application. Cultivar-related differences in grain yields were observed in treatments with low and medium N supply. High doses of N supply resulted in grain yield adjustment or grain yield advantage for cv. Toronto. The results of this study revealed a consistent, genotypic pattern in response to N fertilization in spite of strong seasonal effects. Systematic modifications in canopy growth rates in response to N supply were of particular relevance and a main factor for differences in tillering intensity resulting in modified stand densities. In the present study, cultivar differences in spike development and interactions with N supply related more to abortion than to initiation processes for number of spikelets and number of flowers per spikelet. High grain density (grains per m²) of cv. Toronto was evident during reproduction stages even under conditions of medium N supply. However, decreased growth rates during the later part of grain filling in combination with low 1000 grain weight, which was barely modified by N fertilization, allowed only partial utilization of this potential. It is assumed that sink limitations were of particular relevance for grain yield development in cv. Toronto, while cv. Batis combined a less intense response to N supply with more stability in the development of grain yield components.     

对小麦F1代正反杂交组合的灰色关联度分析

运用灰色系统的理论和方法,对2002～2003年18个小麦F1代正反杂交组合的7个主要性状进行综合分析,计算其灰色关联度,分析正反杂交组合的差异,结果表明:200237品系最好,200212品系次之,200246品系最差.同时只有200237和200238、200213和200214品系的正反杂交组合表现为优良组合.     

再论生长的冗余

生长冗余概念是由盛承发在１９９０年首先提出来的。本文从作物个体与群体对立统一关角度出发提出了作物生长冗余的一个解释。盛承发提出的随机波动环境假说可以导致生长冗余的产生；但是，他从物种利益角度出发解释生物进化还有待商榷。本文还综述了黄土高原阗干旱雨养农业地区小麦根系生长冗余问题，并根据前入工作提出适度增加播种深度和苗期叶片刈割等高产栽培措施。     

不同包被液对ELISA检测五号病病毒抗体的比较试验

０．０５ＭｐＨ９．６碳酸盐缓冲液和０．０５ＭＰＨ１３ＮａＯＨ溶液作为包被液，分别用于间接ＥＬＩＳＡ检测乙型五号病病毒抗体。结果表明，用０．０５ＭＰＨ１３ＮａＯＨ溶泡包被可完全灭活五号病病毒抗原而用０．０５ＭＰＨ９．６碳酸盐缓冲液却有８７％的五号病病毒抗原未被杀灭；用于检测时，以０．０５ＭＰＨ１３ＮａＯＨ溶液为包被液在敏感性及检测结果的梯度方面都优于用０．０５ＭＰＨ９．６碳酸盐缓冲液。     

妊娠黄牛的血液动力流变学观察

首次应用XXG－A型心血管功能测试仪以无创伤检测技术对16例妊娠黄牛22项血液动力流变学指标做了检测，并首次对怀孕黄牛的血液动力流变学特征做了报道。     

Development of a semi-selective medium and an immunofluorescence colony-staining procedure for the detection of Clavibacter michiganensis subsp. sepedonicus in cattle manure slurry

Various compounds and basal media were tested for their suitability to create a semi-selective medium for isolation ofClavibacter michiganensis subsp.sepedonicus (Cms) from cattle manure slurry containing c. 10⁸ colony forming units (cfu) per ml.Plating efficiency of Cms in yeast glucose mineral medium (YGM) was 104% compared with yeast peptone glucose medium. Nalidixic acid, polymyxin B sulphate and the experimental disinfectant S-0208 inhibited colony growth of cattle slurry bacteria as compared with Cms in YGM. The optimal concentration of these inhibitors in combination was determined by modified agar diffusion tests and by pour plating in 24-well tissue culture plates. The semi-selective medium YGMI consisted of YGM supplemented with nalidixic acid (2 mg/l), polymyxin B sulphate (30 mg/l) and S-0208 (125 mg/l). Plating efficiency varied for Cms between 50.9 and 69.6%, for cattle slurry bacteria between 1.8 and 2.5% and for saprophytes from potato heel end extracts between 11.5 and 27.4%.Differentiation of Cms colonies from other colonies was based on their small and bluish colony morphology in pour plates and on immunofluorescence colony-staining (IFC). IFC of a pure culture of micro colonies of Cms in YGM was possible after one day incubation (colonies c. 5 cells). Green background fluorescence in the agar gels was prevented by addition of Tween 20 (0.1%) to the washing buffer and the use of 1% agar gels. IFC of macro colonies of Cms in YGMI, visible with 4x objective magnification, was possible after 4 days. The detection level of the target organism in artificially inoculated cattle slurry in YGMI based on colony morphology varied between 1.4×10³ and 2.3×10⁴ cfu per ml of cattle slurry. Miniaturized plating combined with IFC, using wells in tissue culture plates (=16 mm), proved suitable for detection, but was c. 30 times les sensitive. The recovery of Cms was negatively correlated with the number of saprophytic colonies in the agar plates (R ²=0.74).     

Resistance to yellow rust in Triticum dicoccoides. II. Crosses with resistant Triticum dicoccoides sel. G-25

A comparison was made between the genes in 29 new selections of wild emmer wheat resistant to yellow rust over wide geographic areas and the previously extensively studied selectionTriticum dicoccoides G-25. In 23 selections the resistance may be conferred by 1 dominant gene; these include 11 selections in which the gene is different from the dominant gene in sel. G-25 and two others in which the genes were closely linked or allelic to the gene in G-25, differing from sel. G-25 by race-specificity. Two dominant genes different from the gene in sel. G-25, seem to be present in one selection. In five selections the resistance may be conferred by one or two recessive genes, including three instances in which the recessive gene was associated with a dominat gene. Our findings show that at least 19 out of the 29 selections studied possess genes which are different from the gene inT. dicoccoides sel. G-25.Samenvatting In dit onderzoek werden 29 nieuwe resistente wilde-emmer selecties (Triticum dicoccoides) gekruist met de reeds uitvoerig bestudeerde resistente selectie G-25, om na te gaan of de resistentie van de nieuwe selecties wordt veroorzaakt door genen op dezelfde locus als het dominante gen in sel. G-25 of dat er andere loci bij zijn betrokken. De ouders, de F₁-en F₂-populaties van een bepaalade selectie werden in het kiemplantstadium getoetst met één Israëlisch gele-roest isolaat van fysio 2E0 of van fysio 2E18. In de uitsplitsende F₂-populaties werden de niet-sporulerende planten als resistent beschouwd en de sporulerende als vatbaar.In de F₂-populaties van 12 herkomsten werden geen vatbare planten gevonden, hetgeen er op duidt dat de resistentie wordt veroorzaakt door een gen op dezelfde locus als het gen in G-25 of door een gen dat neuw gekoppeld is aan het gen in G-25. Voor twee van deze herkomsten kan op basis van een fysio-specifieke interactie worden vastgesteld dat de resistentie berust op allelen die verschillen van het allel in sel. G-25. In 11 herkomsten werd een uitsplitsing voor twee dominante gene gevonden (RS=151), waarbij het tweede dominante gen uit de getoetste nieuwe selectie afkomstig is. De aanwezigheid van twee dominante genen verschillend van het gen in sel. G-25 werd gevonden in één herkomst (631). In de overige vijf selecties bleek de resistentie te worden veroorzaakt door één of twee recessieve genen waarnaast in drie gevallen ook nog een dominant gen werd gevonden.De resultaten tonen aan dat tenminste 19 van de 29 bestudeerde selecties resistentiegenen bezitten die verschillen van het gen inT. dicoccoides sel. G-25. Slechts in twee van deze selecties kan het gen allel zijn met het gen in sel. G-25.     

苹果退绿叶斑病毒组织印迹的免疫法检测与定位

用组织培养技术将富士苹果茎尖外植体建立在ＭＳ培养基中,形成试管苗。取４—６周龄的茎与愈伤组织,徒手切取约１ｍｍ厚的横切面,印迹在硝化纤维膜上。印迹组织经封闭后,与ＣＬＳＶ碱性磷酸酶标抗体反应。对反应结果进行显色。感染ＣＬＳＶ的印迹组织呈紫色反应,正常组织无显色反应。结果表明,该方法十分容易检测印迹组织中的ＣＬＳＶ。带毒愈伤组织较茎的显色反应敏感,显色反应时间仅为茎的一半（１５ｍｉｎ）。ＣＬＳＶ在愈伤组织中有两种分布情况：一是所有组织均有显色反应;二是呈不均匀分布。ＣＬＳＶ在茎组织中有三种分布情况：第一,除髓部外,表皮、皮层及维管系统中均有分布;第二,不均匀分布,ＣＬＳＶ集中分布于表度组织中,在皮层及韧皮部仅有少量分布;第三,“嵌合”分布,即同一种组织中部分组织带毒,部分为正常组织。     

Fusarium head blight and mycotoxin contamination of wheat,a review

Summary An infection of bread wheat by fusarium head blight contaminates the crop with mycotoxins, particularly deoxynivalenol (DON) and nivalenol (NIV). The toxicity and natural occurrence of these mycotoxins in wheat are reviewed. Based on 8 years data of fusarium head blight epidemics of wheat in the Netherlands, DON contamination of the grain was estimated. Fusarium head blight ratings averaged an infection of 1.7% of all spikelets; estimates for DON contamination averaged 0.9 mg kg^–1. Taking a guideline level for DON in uncleaned bread wheat of 2 mg kg^–1, in 1979 and 1982 a wheat crop was produced with estimated DON concentrations above the limit of tolerance. Human and animal exposure to mycotoxins in the Netherlands appears to be small but chronic. The information presented in this paper illustrates the need for an annual evaluation of the crop for fusarium head blight incidence and mycotoxin content, and the necessity of fusarium head blight resistant wheat cultivars.Samenvatting Aaraantasting van tarwe doorFusarium culmorum enFusarium graminearum leidt tot vorming van mycotoxinen in het graan, waarvan deoxynivalenol (DON) en nivalenol (NIV) de belangrijkste toxinen zijn. In dit artikel wordt een overzicht gegeven van de toxicologische aspecten, en het voorkomen van deze toxinen in tarwe. Informatie over DON en NIV in tarwe in West-Europa is schaars. Gebaseerd op gegevens vanFusarium epidemieën in de jaren 1979–1986 wordt een schatting gegeven van de concentratie DON in Nederlandse tarwe. Rekening houdend met de herkomst en verwerking van tarwe, blijken zowel in dierlijk als menselijk voedsel lage concentraties DON chronisch voor te komen. Op basis van een maximaal toelaatbare dagelijkse dosis DON van 3 g kg^–1 lichaamsgewicht is de schatting van de dagelijkse opname van DON in het jaar volgend op de oogst van 1982 net op de grens. Zowel een jaarlijkse inventarisatie vanFusarium aantasting en DON besmetting van het graan, als de ontwikkeling vanFusarium-resistente rassen zijn noodzakelijk.