拮抗茄子黄萎病菌土壤放线菌的分离筛选和鉴定

为了研究土壤拮抗性放线菌对茄子黄萎病的生防价值,从陕西省延安市宝塔区与汉中地区土壤中分离、纯化获得154株具有纤维素降解活性的放线菌。采用平板对峙培养法进行初筛,用生长速率法对抑菌效果较好的菌株ZX-10-4进行抑菌谱的测定,并进行盆栽试验验证其对茄子黄萎病的防治效果,通过形态、培养特征及16S rDNA序列分析研究其分类地位。结果显示,有17株放线菌对茄子黄萎病菌抑菌效果较好且抑菌活性稳定,其中菌株ZX-10-4的抑菌活性最高,抑菌率达90.15%;活性菌株ZX-10-4发酵原液对茄子黄萎病的保护和治疗作用分别为70.00%和60.33%,稀释5倍液的防效也在50%以上。根据形态、培养特征、生理生化指标和16S rDNA序列分析,初步确定菌株ZX-10-4为白网链霉菌Streptomyces albireticuli的近似种。     

低山丘陵区基本农田保护研究

基于对广安市上一轮土地利用总体规划(1997-2010)进行了评价和分析,笔者认为广安市上一轮土地利用总体规划存在以下不足基本农田保护指标过大(256836.36 hm2);重视指标控制,轻空间控制;保护的位置缺乏科学规划等.通过基本农田的保护现状的研究,确定了广安市新一轮土地利用总体规划中基本农田的保护数量(hm2)和保护重点.在新形势下,广安市土地利用总体规划将在指标的基础上,更需从上空间上、质量上和类型上开展基本农田的保护,以确保广安地区粮食安全.     

番茄单果质量、果肉厚度及心室数的遗传效应分析

对番茄的单果质量、果肉厚度、果实心室数3个数量性状进行了遗传效应及遗传相关性分析,并估算了控制这些性状的最少基因数目.结果表明:单果质量、果肉厚度、果实心室数的遗传符合加性-显性模型,其广义遗传力分别为54.89%、47.58%及42.26%,狭义遗传力分别为54.20%、40.99%及40.86%;最少控制基因数目分...     

基于热平衡法检测植物茎流传感器的标定

植物茎杆的茎流量是植物重要的生理信息之一,该文主要是对基于热平衡法的植物茎流传感器进行标定试验的研究,通过标定试验,测试了茎流检测装置的性能。试验结果表明,计算出传感器输出值与茎流量有很高的决定系数R2=0.96～0.97,分辨率为1×10-3 g/min,精度为±3%。因此参照标定试验,可以较准确地获取植株茎流速率,进而可以反映出植物的蒸腾及需水状态信息,并据此可以为植物生长环境的调控、节水灌溉等提供有效的监测工具。     

A Literature Review of Uncertainties in Studies of Critical Loads for Acidic Deposition

Uncertainties in the assessment of critical loads for acidic deposition are caused by the choice of biological indicators (BI), critical chemical values (CCV), the current methods used to determine critical loads for an ecosystem, and deficient field data. This paper focuses on the present steady-state mass balance (SSMB) approach, dynamic models and the importance of changes in atmospheric base-cation deposition (BCD), particularly in China. It is argued that 1) for the SSMB approach much uncertainty may come from the choice of BI and the related CCV, and long-term and large-scale monitoring data on weathering rates and growth uptake are urgently needed, especially in China, 2) significant uncertainty may be caused by changes in BCD during SO₂ emission controls, particularly in China, 3) constructing a mechanistic Al submodel may be a promising direction for dynamic models, and 4) the nutrient cycle in the vegetation through biogeochemical processes should be incorporated into dynamic models but the input requirements should be moderate for broad application considerations. Generally higher BCD, different soil components and characteristics and different vegetation types in China compared to Europe and North America suggest that more field investigations on BI and their corresponding CCV be carried out before application of current approaches to specific areas, particularly in China.     

温度与饲粮维生素C水平对后备蛋鸭血清免疫和抗氧化指标的影响

本试验旨在研究温度与饲粮维生素C水平蛋鸭的血清免疫和抗氧化指标的影响.选取12周龄金定鸭216只,温度设低温(2±1)℃和适温(18±1)℃2个水平;饲粮中的维生素C添加水平分别为0、200和800 mg/kg.试验共6个处理,每个处理6个重复,每个重复6只试验鸭.试验期为6周.试验结果表明:1)低温使血清维生素C浓度显著降低了27.78%(P＜0.05),对氧化氢酶(CAT)、总抗氧化能力(T-AOC)、丙二醛(MDA)、白介素2(IL-2)、免疫球蛋白(IgG、IgA、IgM)、生长激素(GH)、胰岛素(Ins)、胰岛素样生长因子(IGF-I)、瘦素(Lep)、皮质醇(Cort)、三碘甲状腺原氨酸(T3)和甲状腺素(T4)的含量影响显著(P＜0.05);2)饲粮中添加200 mg/kg维生素C时,血清维生素C、IGF-I、Lep水平显著升高(P＜0.05),Cort浓度显著降低(P＜0.05);3)温度和维生素C的交互作用对Cort的含量的影响极显著(P＜0.01),对IGF-I、Lep、IgG和IgA的含量影响显著(P＜0.05),对GH、Ins、维生素C、L3、T4及各个抗氧化指标的影响没达到显著水平(P＞0.05).结果提示,低温影响后备蛋鸭血清维生素C的浓度,但饲粮中添加200 mg/kg维生素C时,可提高在低温条件下的后备蛋鸭血液维生素C的水平、提高血液中Lep和IGF-I的浓度、增强机体抗氧化和抗寒冷应激能力.     

木立芦荟挥发油成分GC-MS分析

用气相色谱-质谱法对木立芦荟的挥发油进行化学成分分析.采用水蒸气蒸馏法从木立芦荟中提取挥发油,用归一化法测定其百分含量,并用气相色谱-质谱法对化学成分进行鉴定.共鉴定了19种成分,占挥发油总量的63.66％以上.本方法稳定可靠、重现性好,适用于中药挥发油的化学成分分析.     

Effects of Dietary Lipids on Growth and Feed Utilization of Jade Perch,Scortum barcoo

To examine the effects of dietary lipids on the growth and feed utilization of jade perch juveniles, Scortum barcoo, diets containing 36.3% crude protein supplemented with increasing lipid levels (6, 9, 12, and 15% of the dry matter) were used to feed triplicate groups of 30 fish for 60 d. At the end of the experiment, more than 95% fish survived well from all diet groups (P > 0.05). Measurements on the weight gains and the daily specific growth rates indicated that fish fed with diets of 12 and 15% lipids exhibited higher growth rates (P < 0.05); evaluations for the feed conversion ratio and the protein efficiency ratio indicated that fish fed with 12 and 15% lipid diets used their feed and dietary proteins more efficiently (P < 0.05). The muscle lipid and dry matter contents increased dramatically in fish fed with higher dietary lipid levels (P < 0.05). The highest lipid contents were obtained from fish in the 15% lipid diet group and the highest amount of dry matters from the 12% lipid diet group. On the other hand, protein contents in fish muscles declined with increasing dietary lipid levels (P < 0.05), and the lowest values were shown in the 15% lipid diet group. Ash contents showed no significant differences from muscles of fish fed with four different diets (P > 0.05). Together, increasing lipid levels in fish diets was effective to improve fish growth, feed efficiency, and protein utilization.     

膜片钳技术及其应用

膜片钳技术是在电压钳基础上发展的，将尖端为1μm的玻璃微电极吸附到细胞表面，使微电极与细胞膜形成高阻封接，从而可记录到膜上pA级的离子通道电流，目前已发展了多种记录模式，对细胞进行电压和电流钳制，以观察各种离子通道及其调控。此外膜片钳技术与胞内纤维荧光测钙技术、膜电容监测技术、碳纤维电极局部电化学微量检测技术、逆转录多聚酶链式反应技术（PCR）结合，在药理学、病理学、神经科学、脑科学、细胞生物学和分子生物学等生物科学方面，得到越来越广泛的应用。     

二氧化氮气相污染物被动采样法的研究

运用基于气体分子扩散理论自制的被动采样器,结合Saltzman法,通过该采样器在室内外进行曝露采样检测NO2的含量.该采样器在空气中曝露24个小时后,测定空气中的NO2浓度可达n×10-3mg/m3,与TH-110C型便携式直流大气采样器测定结果比较,误差在30%以内.