恩诺沙星对鸡大肠杆菌病及葡萄球菌病的药效研究

就畜禽专用氟喹诺酮类抗菌药恩诺沙星对鸡人工感染大肠杆菌病及葡萄球菌病的药效进行了研究。结果表明，恩诺沙星、氯霉素对大肠杆菌Ｏ７８的ＭＩＣ分别为０．０５、１．６０ｍｇ／Ｌ；恩诺沙星、红霉素对金黄色葡萄球菌Ｃ５６０５株的ＭＩＣ分别为０．２、３．２ｍｇ／Ｌ。人工发病试验中，恩诺沙星内服以５、１０、２０ｍｇ／ｋｇ剂量或肌注以２．５、５、１０ｍｇ／ｋｇ剂量，每天给药２次，连用３ｄ，对鸡大肠杆菌病及葡萄球菌病均有较好的疗效，其中对大肠杆菌病的疗效明显优于氯霉素     

大白菜新品种中熟5号的选育

自交不亲和系 2 3 5 8s是从大陆型的洛阳大包头中选育的 ;优良自交不亲和系H 1 3 1是从海洋型的本地优质笔尾白的自然杂交后代中分离出的。两个亲本经过严格的抗病性鉴定 ,亲和指数测定 ,配合力分析 ,配制成优良的一代杂种中熟 5号。该品种高抗霜霉病、软腐病、黑斑病、菌核病和病毒病 ,比当地主栽品种增产 10 %以上 ,现已在福建省及其它南方地区大面积推广。     

江西省毛竹栽培区划及立地类型划分的研究

毛竹是江西省重要的经济树种,全省现有毛竹林面积793.7万亩,蓄积95737万根,毛竹生产在全省的林业生产中占有相当重要的地位。本文遵照自然规律和经济规律,以气候、地形和土壤等自然因子为主要依据,同时参照毛竹原有分布数量及社会经济状况,把江西省划分为5个毛竹栽培区。并根据立地因子的差异,应用逐步回归分析方法,寻求出主导因子,把江西省毛竹栽培区内划分出27个不同的立地类型。     

水稻白叶枯病菌两类噬菌体性状的比较

 从感染白叶枯病的稻叶、种子和田水中先后分离到24株噬菌体,测定了它们在琼胶平板上形成噬菌斑的大小、血清学反应、热钝化温度、铁盐的钝化作用、寄主范围、一级生长曲线以及在电镜下观察它们的形态。根据测定结果,可将它们区分为两个类群。第一群称为XOP 1型,以OP-3为代表,其噬菌斑直径为3~5毫米,热钝化温度为58℃/10分钟,易为三价铁盐所钝化;寄主范围较窄;潜育期为40分钟,上升期30分钟,平均裂解量为35个。第二群称为XOP 2型,以OP-12为代表,噬菌斑小,热钝化温度68℃/10分钟,对三价铁盐不敏感,潜育期80分钟,上升期50分钟,平均裂解量为8个。它们都是蝌蚪形,但OP-3的尾部细长而不能收缩,OP-12的尾部短粗而能收缩。     

Cell type-specific characterization of nuclear DNA contents within complex tissues and organs

Background  

Eukaryotic organisms are defined by the presence of a nucleus, which encloses the chromosomal DNA, and is characterized by its DNA content (C-value). Complex eukaryotic organisms contain organs and tissues that comprise interspersions of different cell types, within which polysomaty, endoreduplication, and cell cycle arrest is frequently observed. Little is known about the distribution of C-values across different cell types within these organs and tissues.     

Polymorphism of the DQA2 gene in goats

Variation in the caprine DQA2 gene was investigated using PCR-single-strand conformational polymorphism (SSCP) and DNA sequencing. Eleven DQA2 alleles were defined by SSCP patterns from 23 goats. All the caprine alleles shared high sequence homology to ovine DQA2 sequences, and exhibited a pattern of polymorphism similar to DQA2 alleles from sheep and cattle but different from caprine DQA1 sequences. Thirty-eight AA positions in the alpha1 domain of caprine DQA2 molecules were polymorphic, and a high degree of polymorphism was observed in the putative antigen-binding region, with 74% of the positions being polymorphic. Phylogenetic analysis of caprine, ovine, and bovine DQA sequences revealed that the caprine DQA2 sequences identified here grouped with ovine DQA2, bovine DQA2, DQA3, and DQA4 sequences but are separate from the group of caprine DQA1 alleles. Nine of the caprine DQA2 sequences were more similar to ovine DQA2 alleles, whereas the remaining two were more closely related to ovine DQA2-like and bovine DQA3 alleles. This finding suggests that the caprine DQA2 sequences may represent two loci, which probably arose by either gene duplication or gene conversion events. Allelic lineages were evident for both DQA2 and DQA2-like loci, supporting the trans-species mode of evolution of major histocompatibilitly complex genes. The high level of polymorphism and similarity between caprine and ovine DQA2 alleles suggests that the DQA2 gene may play an important role in immune responses to shared pathogens.     

水稻和李氏禾属植物上四种Xanthomonas属病原细菌氮素营养的研究

 试验结果证明:X.oryzae不能利用硝态氮,对氨态氮的利用能力也很差。X.protypus的菌株O-722对硝态氮和氨态氮的利用能力都很强。X.oryzicola、X.leersiae和X.protypus的菌株LS-9则介乎两者之间。若以蔗糖代替葡萄糖作碳源,则X.oryzae对铵盐的利用能力显著增强。X.oryzae对氨基酸等的要求较X.oryzicola严格。对X.oryzae生长最适宜的氨基酸是L-谷氨酸、L-门冬氨酸、L-脯氨酸和L-丙氨酸等,以L-谷氨酸最好。X.oryzicola适宜的氨基酸与上述相似,但是种类更多一些。因此,白叶枯病的发展与水稻营养状态之所以有密切的关系,这与白叶枯病细菌的营养特征有关。水稻细菌性条斑病细菌对氮肥的反应不象白叶枯病菌那样敏感,可能是条斑病细菌对氮素营养的要求不如白叶枯病细菌严格的原故。试验结果还指出,致病性强弱不同的细菌对氮素营养的要求不同,接近于腐生的弱寄生性菌(X.protypus),对硝态氮和氨态氮的利用能力都很强。因此,在一系列有亲缘关系的细菌中,随着致病性的增强,对氮素营养的要求也可能相应地更加严格。     

家蚕原种人工饲料适应性品系的选拔

研究了家蚕中、日系原种与杂交种对人工饲料适应性的差异；经累代定向选择，建立了苏５、青松人工饲料适应性品系，该品系对人工饲料适应性比非选拔系有明显提高，配以优良的原种饲料，进行原种稚蚕人工饲料育，综合成绩基本达到桑叶育水平。     

单、复式移虫育王对王台接受率和蜂王初生重的影响

对单、复２种不同形式移虫育王的王台接受率和蜂王初生重进行了对比试验．试验结果显示：（１）单式移虫的王台接受率（５８．１１％）与复式移虫的王台接受率（６２．６７％）差异不显著（Ｐ＞０．０５）；（２）单式移虫育出的蜂王初生重（Ｘ＝２３５．９６ｍｇ）与复式移虫育出的蜂王初生重（Ｘ＝２４１．５７ｍｇ）差异不显著（Ｐ＞０．０５）．据此，我们认为培育蜂王应采用单式移虫以省工省时．     

中国东北部针叶林种实害虫调查报告

本文是1987年7—8月中法联合调查中国东北部针叶树种实害虫的初步结果,所调查地区有:黑龙江省小兴安岭的五营自然保护区、丰林林业局的母树林、东北林业大学凉水自然保护区;内蒙古大兴安岭的乌尔旗汗和库都尔人工,天然落叶松母树林以及黑龙江省植物园和东北林业大学哈。尔滨林场所调查树种有:兴安落叶松、红松、樟子松、黑松、红皮云杉、鱼鳞云杉及白皮冷杉。在球果内共发现15种害虫及其被害状,其中最主要的为害落叶松球果的Lasiomma属种类,落叶松球果被害率可达42—95％;其次是落叶松球果小卷蛾,球果被害率达6—2O％;第三位是球果螟,球果被害率达4—8％。 还发现冷杉球果花蝇[L.abietis(Huckett)]和冷杉球果小卷蛾(Barbara herrichiana Obraztsov),它们是我国的新记录。