快速与慢速肉鸡脂肪生长与肌苷酸含量比较

本试验旨在相同条件下,比不同品种和性别肉鸡的脂肪生长量和肌苷酸含量及其相互关系。比较发现:(1)快速与慢速肉鸡的各项脂肪指标均无显著差异(p>0.05),但慢速鸡的肌肉脂肪、皮下脂肪和腹脂率分别比快速鸡高7%、13%和37%;(2)慢速肉鸡肌苷酸含量比快速高50%,且差异显著(p<0.05);(3)母鸡皮下脂肪(p<0.01)和腹脂率(p<0.05)显著高于公鸡,母鸡肌间和肌肉脂肪也分别高于公鸡6%和12%(p>0.05);(4)肌苷酸与腹脂率存在显著正相关(r=0.61,p<0.05)。     

绵羊耳成纤维细胞的体外培养

用组织块法和冷消化法对绵羊耳成纤维细胞在含血清培养液(RPMI—1640)中进行原代和传代培养，探讨动物体细胞培养模式，并对正常细胞形态进行观察。结果表明组织块法和冷消化法培养可获得比较均一、稳定的细胞群，细胞呈典型的成纤维形态，并成功进行传代培养，建立了绵羊耳成纤维细胞系。     

龙牧807苜蓿选育报告

从龙牧803(Medicago sativa L.cv.Longmu 803)苜蓿群体中选择优秀单株,通过无性扦插繁殖,3次混合选择、开放授粉及品种比较试验、区域与生产试验,历经12年育成龙牧807苜蓿(Medicago sativa L.cv.Longmu807)新品种。该品种株型直立,在黑龙江省地区4月中下旬返青,生育期120 d左右,开花期株高75.7~105.3cm,成熟期株高98.5~133.8 cm。2年生干草产量为11739.14 kg·hm^-2,比对照龙牧803苜蓿(9797.99 kg·hm^-2)增产17.10%;种子产量284.60 kg·hm^-2,比对照(230.00 kg·hm^-2)增产18.25%。初花期粗蛋白含量19.38%,适口性好,饲用品质优良。其抗性强,生态适应性广,适宜在黑龙江省各地及毗邻省区推广种植。     

ST贴壁细胞悬浮驯化及应用

为将ST贴壁细胞通过自主驯化,使其能在ST-S细胞无血清培养基中悬浮生长且能稳定传代,在摇瓶中实现高密度生长,并应用于猪伪狂犬病毒(PRV)悬浮培养,经ST-A低血清培养基适应培养,对一株贴壁的ST细胞进行了无血清的全悬浮驯化,并将PRV在悬浮细胞中连续盲传培养。结果显示:ST悬浮细胞能在无血清培养基中传代,培养48 h至第3代后,所能达到的最终细胞密度为3.00×10^(6 )cells/mL以上;PRV连续培养至第5代,毒价可达到109.0 TCID50/mL。结果表明,用专用培养基可使ST贴壁细胞实现悬浮驯化,并可应用于PRV悬浮培养。本研究为获得高密度ST悬浮细胞和提高PRV增殖效率奠定了技术基础。     

基于BP神经网络的工业生态安全动态评价及障碍因子诊断

[目的]对安徽省工业生态安全进行评价和预测,为安徽省工业生态安全可持续发展提供科学依据.[方法]基于压力、状态、响应框架和生态、环境、经济、社会框架构建工业生态安全评价指标体系,采用聚类工具进行安全等级划分,结合熵权法和综合指数法评价2009-2018年安徽省工业生态安全水平,运用BP神经网络模型对2019-2025年...     

红鳞蒲桃苗木生长和生理生化特征对不同盐分和干旱胁迫的响应

以1年生红鳞蒲桃盆栽苗木为研究对象,设置不同盐胁迫浓度及干旱程度,研究盐旱交互作用对红鳞蒲桃苗木的高、地径生长和各项生理指标的影响。结果表明：干旱和盐胁迫都抑制了红鳞蒲桃的生长,盐胁迫的影响要大于干旱胁迫,高生长受到的限制大于地径生长,2 g/kg盐分浓度在水分充足条件下促进了地径生长。相对电导率和丙二醛含量均随着干旱和盐胁迫的增强而增大。不同盐分浓度下,干旱胁迫对相对电导率的影响趋势一致,不同盐分胁迫的影响差异不显著。高盐浓度下丙二醛含量的增加显著大于低盐浓度,表明盐胁迫对红鳞蒲桃的伤害更大;红鳞蒲桃的渗透调节物质在干旱和盐交互胁迫下有一定程度的提高。水分充足时,盐分浓度的变化没有对红鳞蒲桃的游离脯氨酸含量产生影响。随着胁迫的增加,渗透调节能力显著提高。低盐浓度下,抗氧化酶活性在水分充足时没有受到显著影响,高盐浓度下,随着干旱胁迫的加剧则显著提高。     

豚草粗提物对杨树水泡型溃疡病的抑菌作用研究

为解决豚草提取物在林业病虫害防治中的推广与应用问题,以豚草叶片为试验材料,采用温浸-超声波联合提取法提取抑菌活性物质,并开展其对杨树水泡型溃疡病病原菌的室内外抑菌试验。室内抑菌试验表明,粗提物浓度为16 mg/mL时,抑菌率达到73.62%;林间防治试验表明,最小抑菌浓度为 40 mg/mL,抑菌率达到95.14%。通过以上抑菌试验确定豚草粗提物对杨树水泡型溃疡病有较好的抑制效果。     

Influence of Ammoniacal Copper Quaternary treatments on mechanical properties of blue-stained Lodgepole Pine wood

Three concentrations （2.8%, 2.0%, 1.2%） of Ammoniacal Copper Quaternary （ACQ） was selected to treat Lodgepole pine wood for evaluating ACQ treatment on mechanical properties of blue-stained wood. The bending modules of elasticity （MOE）, modules of rupture （MOR）, toughness and shearing strength parallel to grain on tangential surface, are tested according to the criteria GB1927-1943-91. Non-treated sample were also tested according to the same procedure. The results showed that the three groups specimen impregnated by different concentrations of ACQ solution met the AWPA standard 2003 of America （UC4A 6.4g/cm^3）. There were significant difference of toughness between treated wood and non-treated wood （p=0.01）, but there were no statistically significant differences among three concentrations in terms of toughness, and toughness of treated wood was approximately 20% lower than non-treated. MOR, MOE as well as sheafing strength parallel to grain were found to be not significantly different between treated wood and non-treated one, and there were no statistically significant difference among three concentrations of ACQ too. Toughness, MOR, MOE and sheafing strength parallel to grain increased with decrease of concentration of ACQ, but they were hardly affected by ACQ preservatives.     

Farm Forestry Prospects Among Some Local Communities in Rachuonyo District,Kenya

Deforestation and degradation of productive lands are serious threats to the sustainability of forestry/agricultural practices in Kenya. In the last two decades farm forestry (FF) has been promoted through pilot projects among local communities as an example of sustainable land use. However adoption of FF is limited outside the project locations because FF improvement measures focused mainly on biological (e.g. succession, biodiversity and traditional industrial timber production) and technical concerns (e.g. material input delivery such as providing free tree seedlings for field planting) rather than local values, and interests and the constraints facing farmers. This study examined the local farm priorities and constraints and the prospects for the wider implementation of farm-level tree planting in four communities in Rachuonyo District. Using interviews with 597 randomly selected household heads, the study assessed farmer’s production assets and activities, land tenure, priority tree species and the constraints to growing trees on farms. Results show that farm labour is represented by a young population, 56.3% under the age of forty. They are mainly engaged in small-scale mixed cropping integrated with multipurpose trees and some livestock. Tree products contribute about 32% to household cash income, more than any other source (agricultural products, labour sales, etc). Females were more often household heads and had considerable influence over productive activities, making them an important target group in FF development. Farmers preferred exotic tree species due to their ability to provide short-term cash income, fuel and shade. Farmers’ concerns included population pressure on limited farmlands and the problem of credit for agricultural inputs. Given the feeling of secured tenure arrangement and influence of tree products on the household economy, farmers are likely to invest more in efficient land uses such as FF if consideration is given to local priorities.     

Using leaf tip necrosis as a phenotypic marker to predict the presence of durable rust resistance gene pair <Emphasis Type="Italic">Lr34</Emphasis>/<Emphasis Type="Italic">Yr18</Emphasis> in wheat

Fifty wheat varieties along with Jupateco-73 and Morocco were studied for the expression of leaf tip necrosis (LTN), a trait linked with the durable rust resistance gene pair Lr34/Yr18. LTN was frequent (i.e., ≥6) in nine replications of a field experiment over 3 years in 17 genotypes, and the varieties were considered positive for LTN. In molecular analyses of these varieties, having relative severity values up to 78 for yellow rust and 45 for leaf rust, the 150-bp Lr34/Yr18-linked allele was consistently amplified. Expression of LTN in six of nine replications is an appropriate threshold for predicting the presence of Lr34/Yr18 gene pair, and genotypes can be selected using this trait.