以南非肉用美利奴绵羊为父本的不同组合杂种的生长发育

试验以南非肉用美利奴绵羊为父本,以考力代、夏洛莱、本地羊、小尾寒羊、夏考和夏土F1代杂种为母本,比较各组合杂种生长发育的差异。所研究的性状包括初生重、断奶重、6月龄重、周岁重、断奶前日增重(ADG1)、断奶至6月龄日增重(ADG2)。数据使用SPSS统计软件的GLM过程和Ducan氏多重比较。结果表明,母亲年龄对初生重影响显著(P0.01)。出生类型、杂交组合、性别对初生重、断奶重、断奶前日增重以及断奶至6月龄日增重影响显著(P0.01)。出生月份对所有性状影响显著,1～2月出生的杂种初生重和6月龄重显著大于3～5月出生的杂种(P0.05)。南寒ADG1为335 g.d-1,显著高于其它五个组合,但其ADG2为-173 g.d-1,明显弱于其它组合(P0.05)。     

李子反季节栽培技术

介绍李子的特性,积极探索研究了李子反季节栽培技术,经过不断的观察研究,初步总结出李子反季节栽培技术。     

沼液在水稻秧苗培育中的应用

研究了不同浓度沼液对杂交水稻种子浸种和秧苗培育的影响,结果表明,使用沼液比重在1.002-1.005g/cm3,对杂交稻种子发芽率、成秧率和秧苗生长质量都有良好的促进作用,同清水对照相比,其发芽率、成秧率和秧苗生长质量各项指标都达到显著或极显著,但使用超过比重为1.009g/cm3时都有明显的抑制作用,发芽率降低,秧苗生长不均匀。     

山茶花灰斑病菌生物学特性研究

 山茶花(Camellia japonica L.)灰斑病菌[Pestalotiopsis guepini (Desm.) Stey.]^[1,2,3,4]菌丝生长适温20-25℃,适宜pH值是5-7。在不同培养基里以PDA和燕麦培养基最佳。对碳源的利用以葡萄糖,蔗糖最佳,木糖最差,氮源以门冬酰胺、蛋白胨、酵母液最佳,尿素最差。
分生孢子萌发适温20-25℃,适宜pH值是4-5,在不同营养液里以酵母汁,茶花叶汁萌发最好。在不同光照条件下,自然光和连续黑光灯利于产孢,完全黑暗不产孢。不同培养基里以燕麦和PDA培养基最适宜病菌产孢,在山茶花叶汁与水洋菜培养基里不产孢。     

聚乙烯醇共混改性膜作为农药种衣剂成膜剂的性能研究

以水溶性聚合物聚乙烯醇(PVA)和水不溶性聚合物乙酸乙烯-乙烯共聚物(VAE)乳液为原料,采用溶液共混法制备了PVA-VAE共混膜,为农药成膜剂的制备开辟了新途径。红外光谱、透射电镜、激光粒度仪测试结果显示,PVA溶液中的胶束被打开,体系的比表面积急剧增大,两相间的界面消失,说明共混体系分子间具有良好的相容性;透水性与耐水性测定结果表明,PVA-VAE的质量比为80∶ 20、70∶ 30、60∶ 40时其共混膜的性能适用于农药种衣剂的成膜剂;种子发芽试验显示,与单独使用PVA膜相比,引入适当比例VAE后的共混膜用于种子包衣,其耐水性显著提高,渗水率适宜,对种子发芽无明显影响。     

一株禽流感病毒全基因的序列分析

通过反转录-聚合酶链式反应(RT-PCR)技术对禽流感病毒A/Turkey/Wisconsin/1/66(H9N2)的8个基因片段即PA、PB1、PB2、NS、NP、M、HA、NA分别进行扩增,然后将其克隆到PMD18-T载体后进行序列测定和拼接;并将克隆到的8个基因片段与以下毒株各个基因的相应序列进行比较分析:Duck/HongKong/Y280/97(DHKY280/97)、Duck/HongKong/YT439/97(DHKY439/97)、Quail/HongKong/G1/97(QHKG1/97)、A/Chicken/Beijing/1/94(CBJ1/94)、Chicken/HongKong/G9/97(CHKG9/97)、A/Turkey/California1/66(TC/1/66).结果表明:我们克隆到的TW1/66株的8个基因片段均含有相应病毒基因的完整开放阅读框架:TW1/66的各基因与TC/1/66株相应各基因同源性最高(NS基因除外,同源性只有(67.4%).与其它各毒株各基因同源性均较低,但与DHKY439/97各基因同源性高于与DHKY280/97、QHKG1/97、CBJ1/94、CHKG9/97各基因同源性.     

旱地莜麦多目标动态施肥模式研究

建立莜麦籽粒产量、生物产量、籽粒蛋白质产量、总蛋白质产量与施氮总量及追施比例之间的效应方程,求解不同边际利润下的最佳施氮量及追施比例。结果表明施氮量改变,直接影响最佳追施比例、籽粒产量、蛋白质产量和生物产量等,施氮量在17.25～120.75kg/hm2区间内,各种目标产量随施氮量的增加而稳定增加,在合理的施氮量区间内实现既定产量,施氮总量与追施比例可以消长互替,降低追施比例则增加氮素总量,或增加追施比例则可以减少氮素总量。得出了不同目标产量时的最佳氮肥用量与追施比例和对应于氮肥不同用量的最佳追施比例及理论产量的动态施肥模式的数学方程。     

鄂尔多斯沙区碱湖与螺旋藻资源

通过 1 995 - 2 0 0 1年长期对内蒙古鄂尔多斯高原毛乌素沙地和库布齐沙漠的八个盐碱湖进行了实地调研 ,在其中四个碱湖中发现有四种螺旋藻 ,其中两个为新种 ,另两个为中国新记录种。作者在巴彦淖尔碱湖畔建成半封闭跑道式养殖池 ,以当地的钝顶螺旋藻为藻种 ,利用湖水养殖螺旋藻获得了成功。藻粉产量达到 6 - 8g/d· m2 ,质量通过了内蒙古卫生防疫站“食准字”检验。作者在螺旋藻养殖上的成功 ,为其产业化奠定了基础。在鄂尔多斯沙区发展螺旋藻产业有着得天独厚的优势 :众多的碱湖资源 :特有的螺旋藻资源 ;丰富的光能资源 ;不占用耕地和牧场 ;不污染环境、可持续发展等。所以 ,在鄂尔多斯沙区开发螺旋藻是继化工产业化之后的又一项新兴产业     

乌骨鸡的研究进展及产品开发

论述了我国乌骨鸡的研究现状及其产品开发情况 ,旨在促进乌骨鸡养殖业的发展     

Impacts of atmospheric CO<Subscript>2</Subscript> concentrations and soil water on the population dynamics,fecundity and development of the bird cherry-oat aphid<Emphasis Type="Italic">Rhopalosiphum padi</Emphasis>

The impacts of elevated CO₂ and soil water on the population dynamics, adult fecundity and nymphal period of the bird cherry-oat aphidRhopalsiphum padi (Linnaeus) were evaluated in three experiments: (i)Combined effects of CO ₂ and soil water on aphid populations. Spring wheat was grown in pots at three CO₂ concentrations (350, 550 and 700 ppm) and three soil water levels (40%, 60% and 80% of field water capacity, FWC) in field open-top chambers (OTC) and infested with the bird cherry-oat aphid. Aphid population dynamics were recorded throughout the growing season; at the same time, adult fecundity and duration of the nymphal period were recorded. Chemical composition of spring wheat leaves was also analyzed. (ii)Indirect effects of CO ₂ concentrations and soil water on aphid adult fecundity and nymphal period. The experiment was conducted with the leaf discs method in the laboratory. Aphids were reared on leaf discs excised from the treated wheat in OTC with different CO₂ and soil water levels. (iii)Direct effects of CO ₂ concentrations on aphid adult fecundity and nymphal period. Aphids were reared on leaf discs excised from the wheat grown under natural conditions. The experiment was conducted with the leaf disc method in OTC with the three CO₂ concentrations. It was found that the direct effect of CO₂ concentration on aphid population parameters was minor. CO₂ and soil water affected aphid population indirectly through their effects on wheat characteristics. The aphid population under 550 ppm CO₂ was far larger than the one under 350 ppm CO₂, whereas the population under 700 ppm CO₂ was slightly higher than that under 550 ppm CO₂. The largest aphid population was obtained with the 60% soil water treatment, regardless of CO₂ treatment. The effects of CO₂ concentration on aphid population were, however, not significantly correlated with soil water level. Adult fecundity increased with CO₂ concentration, the highest fecundity being achieved under 60% FWC treatments. The nymphal period was not affected by CO₂ concentration. The shortest period occurred under 60% FWC. Atmospheric CO₂ and soil water had significant effects on the chemical composition of the wheat leaves. Aphid population size was positively correlated with leaf water content, concentrations of soluble proteins, soluble carbohydrates and starch, and negatively correlated with DIMBOA and tannins concentrations. http://www.phytoparasitica.org posting Oct. 20, 2003.