辣椒主要病害抗性的配合力分析

本文用6个亲本,按(1/2)n(n-1)双列杂交法配制15个杂交组合,对辣椒TMV、CMV、疫病、疮痂病抗性进行了配合力分析。结果表明,不同亲本、不同病害抗性的一般配合力效应和不同杂交组合的特殊配合力效应差异较大,疫病抗性显性方差所占份量较大,加性方差所占的份量较小;CMV和疮痂病抗性是加性方差所占份量较大,显性方差所占份量相对较小;TMV抗性介于二者之间。不同病害抗性间所有一般配合力的相关系数均未达到显著水平;特殊配合力是CMV与疮痂病阃的相关达到了极显著水平,TMV与CMV间和疫病与疮痂病间的相关系数达到显著水平。     

钾肥对草坪草抗性的影响

钾肥是草坪草三大营养元素之一，对形成和加强草坪草的抗性起着十分重要的作用。论述了钾肥对草坪草寒、旱、热、病虫害及盐碱等抗性的影响及其作用机理，为草坪建植、管理等生产实践及系统化研究提供一定的依据。     

堆型艾美耳球虫早熟株免疫雏鸡后血清抗体水平动态变化的研究

用堆型艾美耳球虫早熟株对雏鸡进行一次免疫和二次免疫试验 ,研究雏鸡血清抗体的动态变化。试验结果显示 ,在一次免疫试验中 ,各剂量组雏鸡均在免疫后 2天血清抗体出现较高的 OD值 ,之后呈下降趋势 ,11天后逐渐上升 ,到 12～ 13天时出现第 2个峰值 ,各组间的血清抗体 OD值比较 ,3 0 0 0个卵囊 /只剂量组极显著 (P<0 .0 1)高于 10 0 0个 /只、2 0 0 0个 /只和 5 0 0 0个 /只剂量组。在二次免疫试验中 ,8日龄首免、14日龄二免组雏鸡的抗体水平动态变化整体呈上升趋势 ,峰值 (0 .3 75 )出现在二免后第 10天 ,其后稳定地维持在较高水平 (平均 OD值为 0 .3 5 ) ,并且其抗体水平显著地高于 6日龄首免、12日龄二免组 (P<0 .0 5 )。抗体水平动态变化表明 ,堆型艾美耳球虫早熟株有较强的免疫保护力 ,其免疫方式可选用一次免疫 ,剂量为 3 0 0 0个卵囊 /只 ,也可采用二次免疫 ,即 8日龄首免 (15 0 0个 /只 ) ,14日龄二免 (15 0 0个 /只 ) ,从抗体动态变化的稳定性看 ,二次免疫更佳     

高分子吸水剂在沙地植被重建中的盆栽效果试验

本试验于2002年4～10月在红原县进行,其目的在于通过对吸水剂的盆栽试验,探讨吸水剂对植株生长的作用,从而达到节水重建植被的目的。     

Morphological characterization of the interaction between Diplocarpon rosae and various rose species

Blackspot, caused by Diplocarpon rosae , is the most severe and ubiquitous disease of garden roses, but information is lacking about genotype-specific forms of resistance and susceptibility of the host. Macro- and microscopic analyses of 34 rose genotypes with a defined monoconidial culture black spot inoculum identified susceptible and resistant rose genotypes and further genotype-specific subdivisions, indicating the presence of partial forms of resistance and different resistance mechanisms. In total, eight interaction types were characterized, five representing compatible (types 1–5) and three representing incompatible interactions (types 6–8). The incompatible interactions were characterized by the lack of any visible fungal structures beneath the cuticle (type 8), single-cell necroses (type 7) or necroses of larger cell clusters (type 6), the latter two types with penetration hyphae and haustoria in epidermal cells.     

溴隐停对惠州麻肉种鸡产蛋性能的影响

研究目的在于探讨多巴胺受体激动剂(溴隐停)对地方良种肉鸡繁殖性能的影响。方法从628只28周龄健康的“惠州麻”黄羽肉种鸡群中随机选取1组鸡笼内的40鸡作为实验组,其余的作为对照组。实验组鸡群喂服溴隐停,每只鸡每天1.25mg,连用4d,停用4d后再用4d,对照组不使用。结果在4周的实验期内实验组和对照组的产蛋率分别为83.86%和69.96%;破蛋率分别为1.28%和1.69%,畸形蛋率分别为4.33%和1.19%;实验组平均每只鸡的产蛋总数比对照组多3.89个、合格种蛋数多3.26个;药物处理对平均蛋重无显著影响;使用溴隐停能够提高鸡血液中的雌激素水平。结论溴隐停能够通过抑制地方良种肉鸡体内促乳素的合成与分泌,减少抱窝现象的发生,提高其繁殖性能。     

低蛋白质氨基酸平衡饲粮对早期断奶仔猪腹泻和生产性能的影响

本研究选用１８头２８±１日龄断奶的杂交仔猪（平均体重约５．５ｋｇ），研究低蛋白质氨基酸平衡饲粮对早期断奶仔猪腹泻和生产性能的影响。试验结果显示：（１）低蛋白质氨基酸平衡饲粮使仔猪血浆挥发性盐基氨含量、血浆尿素氨含量和腹泻指数降低（Ｐ＜０．０５或０．０１）。（２）采食全植物蛋白型氨基酸平衡饲粮（ＣＰ１８．３％）的仔猪，其平均日增重（ＡＤＧ）、平均日采食量（ＡＤＦＩ）和料肉比（Ｐ／Ｇ）与采食复合蛋白型对照饲粮（ＣＰ１９．７％）的仔猪差异不显著（Ｐ＞０．０５），但前者的增重成本比后者降低（Ｐ＜０．０５）３１％。（３）采食复合蛋白型氨基酸平衡饲粮（ＣＰ１８．４％）的仔猪的生产性能优于采食复合蛋白型对照饲粮（ＣＰ１９．７％）的仔猪，前者的ＡＤＧ和ＡＤＦＩ分别提高（Ｐ＜０．０５）６１％和３２％，Ｆ／Ｇ和增重成本分别下降（Ｐ＜０．０５）２４％和３７％。（４）采食全植物蛋白型氨基酸平衡饲粮的仔猪，其ＡＤＧ和ＡＤＦＩ低于（Ｐ＜０．０１）采食复合蛋白型氨基酸平衡饲粮的仔猪。前者的Ｆ／Ｇ和增重成本趋于高于后者，但差异不显著（Ｐ＞０．０５）。以上结果表明，低蛋白质氨基酸平衡饲粮可显著降低仔猪断奶后腹泻和提高仔猪生产性能。复合蛋白型?     

聚集器式气力集尘装置几个主要设计参数的合理确定

合理确定聚集器的静压、压力平衡基准、聚集器的压力损失、设计流量等参数，对于保证集尘装置工作的可靠性和经济性都有重要意义。     

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).     

Colonization and histopathology of susceptible and resistant carnation cultivars infected with Fusarium oxysporum f. sp. dianthi

Stems of the susceptible Early Sam and resistant Novada carnations were inoculated with a conidial suspension ofFusarium oxysporum f. sp.dianthi. Stem segments of either cultivar were sampled regularly and used for determination of fungal growth and for microscopical investigation.Early Sam showed typicalFusarium wilt symptoms and its stems were colonized intensively. The observed vascular browning appeared to be caused by discolouration of primary walls of infected vessels and surrounding cells. Vessels were rarely occluded with gel. Cell wall degradation led to the formation of stem cavities. Hyperplasia of xylem parenchyma was not seen.In Novada, fungal colonization remained low throughout the experiment. Macroscopic symptoms were absent except for longitudinal bursts in the stem, which appeared to be caused by hyperplasia of xylem parenchyma bordering infection. Vascular gelation occurred in the infected tissues, causing some vascular browning also. Xylem vessel regeneration was observed in the hyperplastic layer. Cavities were not formed, and wall discolouration was rare. Vascular gelation is considered part of theFusarium wilt resistance mechanism. It is followed by xylem vessel regeneration, which expresses a general plant response to vascular dysfunction rather than being part of the resistance mechanism.Although of different origin, vascular browning as such occurs in both susceptible and resistant interactions. In breeding for resistance, care should hence be taken with the current use of browning as an indication of disease.Samenvatting Anjers van de vatbare cultivar Early Sam en de resistente cultivar Novada werden geïnoculeerd met een conidiënsuspensie vanFusarium oxysporum f. sp.dianthi. Van beide cultivars werden regelmatig stengeldelen geoogst om deze microscopisch te onderzoeken en om de schimmelgroei te bepalen.Early Sam vertoonde de voor deze verwelkingsziekte kenmerkende symptomen en werd intensief gekoloniseerd. Aan het vaatweefsel waargenomen bruinkleuring bleek veroorzaakt te worden door verkleuring van de primaire wanden van geïnfecteerde vaten en de hen omringende cellen. Zelden trad er in de vaten gomvorming op. Celwandafbraak veroorzaakte de vorming van holten in de stengel. Hyperplasie van het houtparenchym werd niet waargenomen.In Novada bleef de schimmelgroei gedurende het hele experiment beperkt. Macroscopisch waren er enkel lengtescheuren in de stengel te zien, die veroorzaakt bleken te worden door hyperplasie van aan de infectie grenzend houtparenchym. In het geïnfecteerde vaatweefsel optredende gomvorming veroorzaakte ook enige bruinkleuring. In het hyperplastische weefsel werd regeneratie van houtvaten waargenomen. In de stengel werden geen holten gevormd, en verkleuring van de celwanden kwam weinig voor. De vorming van gommen in de houtvaten maakt waarschijnlijk deel uit van het resistentiemechanisme. De daarop volgende houtvatregeneratie is eerder een algemene reactie van de plant op vaatverstopping dan een deel van het resistentiemechanisme.Vaatverbruining, zij het van verschillende oorsprong, komt voor in zowel vatbare als resistente interacties. Om die reden moet men in de resistentieveredeling bij de anjer voorzichtig zijn met het gebruik van bruinkleuring als ziekteïndicatie.