丹参提取物、蒲公英提取物及其复方对肉鸡生长性能、免疫功能和抗氧化能力的影响

本试验旨在探究丹参提取物、蒲公英提取物及其复方对肉鸡生长性能、免疫功能和抗氧化机能的影响。选取192只1日龄雄性科宝-500肉鸡，随机分成4组，每组6个重复，每个重复8只鸡。对照组饲喂基础饲粮，试验组分别在基础饲粮中添加0.1%的丹参提取物（丹参提取物组）、0.1%的蒲公英提取物（蒲公英提取物组）、0.05%的丹参提取物+0.05%的蒲公英提取物（复方组）。试验期42 d。结果显示：1）与对照组相比，22～42日龄，复方组肉鸡的平均日增重显著提高（P<0.05），蒲公英提取物组和复方组肉鸡料重比显著降低（P<0.05）;1～42日龄，试验组肉鸡的平均日增重均显著提高（P<0.05），料重比均显著降低（P<0.05）。2）与对照组相比，42日龄时，丹参提取物组和复方组肉鸡胸腺指数显著提高（P<0.05），且复方组肉鸡脾脏指数显著提高（P<0.05）。各试验组之间相比，复方组肉鸡42日龄脾脏指数显著高于蒲公英提取物组（P<0.05）；与对照组相比，试验组肉鸡21日龄血清免疫球蛋白A(IgA)、免疫球蛋白G(IgG)、免疫球蛋白M(IgM)含量和42...     

我国蚕业科研机构创新能力的评价与分析

基于为蚕业科研机构正确制定创新战略,提高科研创新能力提供依据的目的,运用层次分析法构建了我国蚕业科研机构创新能力评价指标体系。根据现有19家蚕业科研机构的统计数据,对我国蚕业科研机构的创新能力进行综合评价,并对评价结果进行客观的分析,认为：必须加大对蚕业科研机构的投入,重视蚕业科技人才队伍建设,深化蚕业科研体制改革。     

液压阀插装实验台的设计

怎样快速准确的确定液压阀在液压系统中的故障现象,一直是液压工作者有待解决的问题。该实验台通过某些特殊设计的插装装置和快换管接头,把假设有故障的液压元件和实验台快速连接起来,可进行各种性能检测,确定其损坏程度,从而节省了诊断故障的时间并避免了维修中不必要的损伤。在教学上,该实验台可使实验者自选液压元件,设计、组装液压基本回路或液压系统,从而打破了以往实验者“只能看不能动”的蔽病,提高实验者的动手能力。在工程上,利用该实验台模拟制造的液压系统,可预测其实际工作状况的好坏,从而避免了在实际生产制造中由于某些性能指标达不到要求而带来的不良后果。     

利用原位杂交技术检测新疆牛结核病标本中结核菌的研究

采用原位杂交技术将地高辛标记的牛结核杆菌特异性探针即２４８ｂｐ基因片段用于检测１０份患病牛肺病变组织福尔马林固定切片标本。结果表明：基因探针原位杂交技术对切片标本的检出率较常规涂片染色高,分别为８０％和５０％,其定位观察到组织切片中的结核杆菌,又能获得有关细菌及其周围组织的原有位置关系,是一种敏感、特异的诊断方法,适应于固定标本、涂片标本的结核菌检测。     

黑木耳的抗霉能力,产量性状与不同胞外酶活的相关性

以三个单孢杂交的黑木耳菌株和沪耳1号为材料,研究了不同菌株的抗霉能力,产量以及胞外多酚氧化酶、漆酶、过氧化物酶、半纤维素酶、羧甲基纤维素酶活性之间的相关性。结果表明:不同菌株的抗霉性与产量呈正比,不同的胞外酶活性又与抗霉性有一定的相关性,从而为黑木耳的抗病育种和生产提供了理论依据。     

Competition between sugarbeet and Sinapis arvensis and Chenopodium album, as affected by timing of nitrogen fertilization

The effects of timing of N fertilization (early, standard or late) on competition between two sugarbeet cultivars (Ritmo, semi-prostrate; and Rizor, erect) and two weeds ( Sinapis arvensis and Chenopodium album ) were studied over 2 years at Viterbo. In both years, time of N fertilization did not influence biomass, yield and yield quality of the weed-free crop, but early N fertilization gave higher crop biomass reduction in the presence of S. arvensis and lower crop biomass reduction in the presence of C. album . Root and sucrose yield responded to competition in the same way as biomass. However, percentage reductions were higher, as both weeds affected harvest index. The two cultivars showed the same response to competition. At the weed densities studied, crop competitive ability was favoured by late N fertilization in the presence of S. arvensis and by early N fertilization in the presence of C. album . Crop competition only reduced seed production by C. album but lowered seed germination of both weeds.     

Inheritance of resistance to stem canker (Phomopsis helianthi) in sunflower

Six male sterile sunflower lines were crossed with seven restorers in a factorial mating design. The 13 inbred lines and their 42 F1 hybrids were planted in a randomized block design with three replicates. Each replicate consisted of two rows, 5 m long (30–35 plants per replicate). Resistance to natural Phomopsis infection, presented as the percentage of plants with no encircling necrosis lesions of the fungus on the main stem, was determined at physiological maturity. Analysis of variance showed that female and male general combining abilities (GCA) and specific combining abilities (SCA) of F1 hybrids were significant. The ratio of additive variance to total variance was 0.662, a high value which indicates prevailing additive effects. The additive variance due to females was more important than that of males, probably because of the existence of maternal effects or more effective genes for resistance in the female lines used in this experiment. The estimates of GCA were significant and positive for LC1004A, KO549A, 50KD8 and LC1064C inbred lines. These lines should be considered in developing hybrids with improved resistance to Phomopsis in sunflower breeding programmes.     

基于灰色系统的辣椒新组合配合力综合评判

为在辣椒杂交育种中提高亲本配合力,本文运用灰色系统理论模型,对4个辣椒新组合[34(55)×32(23)、34(55)×48(30)、34(55)×33(24)、34(55)×46-1]及理想品种进行了一般配合力的综合评判。结果表明,以34(55)×33(24)组合的经济性状最佳,各项性状指标与理想品种最为接近,其单果重明显高于其他组合;超双亲平均优势为22.0%,杂种优势指数为122.0%,符合辣椒新品种选育目标。     

甜玉米主要数量性状配合力研究

应用Griffing方法(一)研究了六个甜玉米及到杂交后代的配合力表现．结果表明，穗行数主要受加性基因控制，穗长主要受非加性基因控制。其余大部分数量性状的加性和非加性基因效应同时存在。含糖量的反交效应明显，在育种实践中应予以重视．对于这些性状而言，一般配合力高的亲本容易产生特殊配合力高的组合，。但也不排除从一般配合力都不高的双亲获得较高特殊配合力组合的可能性。根据配合力互补原理可望从这六个亲本间选配出高产高糖组合。     

甜菜雄性不育多倍体新品种吉洮301的选育

甜菜雄性不育多倍体新品种吉洮３０１以雄性不育系７３５ＭＳ系统的３个不育系６５Ａ、６６Ａ、７５／６８Ａ为母本，四倍体品系甜研４０１为父本杂交育成，其三倍体率接近１００％、不育率稳定在９４．４％以上，经试验、生产示范结果，吉洮３０１平均块根产量３５０９．５ｋｇ／亩，比对照提高２６．４２％，该品种出苗势强，叶丛长势繁茂，抗褐斑病（比对照发病降低０．５级），较耐根腐病。