不同产地河北杨苗期研究

对11个产地河北杨的苗期生长进行了研究。通过物候观察、扦插成活率、生长状况及抗性测定等多项指标的研究,结果表明,吴旗11号和西宁5号的种苗在生长量及抗性方面均优于其它产地种苗;皋兰2号种苗次之,但皋兰2号种苗对黑斑病和叶锈病的自然发病率又低于吴旗11号和西宁5号种苗。因此、在生产上应发展吴旗11号、西宁5号和皋兰2号产地的河北杨。     

苏联森林经理工作的现状及发展方向

本文从5个方面论述了最近10多年来,苏联传统的森林经理工艺的进展与改革:(1)伐区工艺改革(包括伐区拨交与验收);(2)各种森林资源调查方法的研究与使用;(3)全苏小班数据库的建立及自动化检索系统的研制;(4)森林经理制图自动化系统的开发与应用;(5)遥感与电算技术发展迅速。文章还介绍了苏联森林经理技术发展的新动向。     

The Survey and Drawing of Common Cylinder Worm

This paper focuses on the standarization of common cylinder worm transmission in the methods and procedures of the survey and drawing.     

田间作业机组合理编组的理论计算及程序设计

拖拉机与农具组成的田间作业机组,要实现机器本身结构和性能与之配套机具的系统协调,获得最佳的运用效果,要进行合理编组计算。该文规范了机组合理编组的理论计算步骤并用ＴｕｒｂｏＣ语言编写了计算机程序。该程序可完成田间三大类作业的合理编组计算工作,如略加修改可以满足更多种机型完成各种作业的合理编组的计算。经上机运算准确、可靠、快捷、方便。     

三峡库区鱼类环境和污染状况

三峡库区的自然环境适合于多种鱼类的生长,库区水质表现一定的季节变化,水体中大肠杆菌和铜等超标;鱼体内主要污染物为Ｃｄ,Ｃｒ,Ａｓ等,但未超标,食用品质较好;鱼样外周血红细胞微 ０．８２‰－４．２８‰,表明水质对鱼体细胞具诱变作用。     

茶叶中自由基的研究

利用ＥＳＲ波谱技术对不同茶类成茶和苦丁茶,七叶参茶的自由基进行了较系统的研究,结果表明：茶叶中含有大量的稳定的自由基,不同成茶自由基含量因茶类不同而有较大差异,各茶类自由基含量高低依次为黑茶、青茶、红茶、黄茶,绿茶、白茶。     

利用RAPD分析药用石斛的遗传多样性及亲缘关系

通过对9种药用石斛进行遗传多样性和亲缘关系的分析,为更好地开发利用石斛资源奠定基础。采用RAPD技术,应用NTSYS软件对9种石斛的RAPD-PCR结果进行分析。利用从103条随机引物中筛选出的70条随机引物对供试材料DNA进行随机扩增,共得到520条带,其中多态性带有491条,多态性百分率为94.42%。采用UPGMA类平均法对扩增出的谱带进行遗传聚类分析,得出反映各种间亲缘关系的树状图。在遗传距离（D）=0.44处,可将供试材料分为2类,RAPD对基因组的分析结果与传统分类学的结果差异不大。试验结果表明,RAPD技术可有效地应用于药用石斛的遗传多样性及亲缘关系的研究。     

Antagonistic activity and protective effect of a Bacillus subtilis isolate against fish pathogen Edwardsiella piscicida

Fisheries Science - Bacillus subtilis ZFB19 isolated from the intestine of healthy grass carp exhibited considerable antagonistic activity against Edwardsiella piscicida which was resistant to...     

The antioxidant status,apoptosis, intercellular integrity and immune function of grass carp (Ctenopharyngodon idella) head kidney and spleen fed different levels of pyridoxine

This study was carried out to investigate the effects of dietary pyridoxine (PN) on the antioxidant status, apoptosis, intercellular integrity and immune function of head kidney and spleen in young grass carp (Ctenopharyngodon idella). Results showed that compared with the optimal PN level, (a) PN deficiency decreased antioxidant enzyme activities and down‐regulated the mRNA levels of antioxidant enzymes, NF‐E2‐related factor 2 (Nrf2), myeloid cell leukaemia‐1 (Mcl‐1) and tight junction proteins, whereas it increased the contents of reactive oxygen species (ROS), malondialdehyde (MDA) and protein carbonyl (PC), and up‐regulated the mRNA levels of cysteinyl aspartic acid‐protease (caspase), Fas ligand (FasL), p38 mitogen‐activated protein kinase (p38MAPK) and myosin light chain kinase (MLCK) in the head kidney and spleen of fish (p < .05). (b) PN deficiency decreased lysozyme (LZ) and acid phosphatase (ACP) activities, and complement contents, and down‐regulated the mRNA levels of antibacterial peptides, anti‐inflammatory cytokines, inhibitor of κBα (IκBα) and target of rapamycin (TOR), whereas it up‐regulated the mRNA levels of pro‐inflammatory cytokines and nuclear factor kappa B p65 (NF‐κBp65) in the head kidney and spleen of fish (p < .05). (c) Dietary PN requirements of grass carp based on the malondialdehyde content and lysozyme activity were estimated as 4.97 and 4.99 mg/kg diet, respectively.     

Use of salmon by‐product meals as a replacement for anchovy meal in practical diets for the Pacific white shrimp (Litopenaeus vannamei)

A series of trials were conducted with Pacific white shrimp Litopenaeus vannamei, to evaluate the efficiency of two salmon meals as compared to anchovy meal. The basal diet contained 200 g/kg anchovy meal, which was systematically replaced (0%, 50%, 75% and 100%) with salmon meal on an isonitrogenous basis. Another two diets were formulated with a hydrolysed salmon meal to replace 50% and 100% anchovy meal. Each diet was randomly fed to four replicate groups of 25 and 30 shrimp per tank in clear (indoor) and green (outdoor) water trials, respectively. The results showed that growth performance and feed conversion ratio were not statistically different when salmon meal replaced anchovy meal in both trials. However, when hydrolysed salmon meal was used to replace 100% of the anchovy meal, growth performance of the shrimp significantly decreased. The four kinds of fish meal (anchovy, salmon by‐product meals and menhaden) were evaluated in an ingredient digestibility trial using the 70:30 replacement technique. In general, dry matter, energy, protein and individual amino acids digestibility of salmon meal were significantly higher than those of menhaden and anchovy meal. Results of this study demonstrated that salmon meals are a good protein sources which can replace anchovy meal.