农业科研信息服务模式初探——以天津市农业科技图书馆为例

分析了农业科研信息资源环境和农业科研人员信息需求的特点,并以天津农业科技图书馆在为农业科研信息服务的实践为例,对农业图书馆为农业科研服务模型进行探索。     

不同激素对怀山药不同外植体分化的影响

研究了6-BA、NAA和IBA对怀山药不同外植体分化和植株再生的影响。结果表明:以节为外植体,改良的MS+100 g/L香蕉+0.5mg/L 6-BA+1.00 mg/L NAA+0.5%琼脂+0.5%活性炭+3%蔗糖培养基为最优组合,其分化率达100%;最适根块分化培养基是,改良的MS+100 g/L香蕉+0.5 mg/L 6-BA+0.25 mg/L NAA+0.4 mg/L IBA+0.5%琼脂+0.5%活性炭+3%蔗糖;最适无菌茎段分化培养基是,改良的MS+100 g/L香蕉+0.5 mg/L 6-BA+0.50 mg/L NAA+0.8 mg/L IBA+0.5%琼脂+0.5%活性炭+3%蔗糖;最适无菌叶柄分化培养基是,改良MS+100 g/L香蕉+1.5 mg/L 6-BA+0.25 mg/L NAA+0.5%琼脂+0.5%活性炭+3%蔗糖。     

Apoptosis and its modulation in type Ⅰ diabetes mellitus

Apoptosis, also known as programmed cell death, is a normal process contributing to tissue tumor during development and in the adult.During development apoptosis is involved in tissue homeostasis and eliminating nonfunctional, superfluous or harmful cells. It is an active process controlled by some gene and factors such as caspases, bcl-2, Fas/FasL and NO. Type 1 diabetes mellitus is regarded as a chronic autoimmune disease resulting from progressive destruction of insulin-producing β-cells in the pancreas. The relationship between apoptosis with its modulation and type 1 diabetes mellitus was reviwed.     

沙尘胁迫对榅桲叶片光合和叶绿素荧光特性的影响

以榅桲（Cydonia oblonga Mill）为研究材料,以无沙尘覆盖为对照（CK）,设置轻度沙尘胁迫（5mg·cm-2）和重度沙尘胁迫（12mg·cm?2）两个处理,并分别在处理第10、20、30和40天时,测定其叶片光合特性和荧光参数的变化。结果表明：沙尘处理下榅桲叶片的净光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr）均随处理时间的延长呈下降趋势,胞间CO2浓度（Ci）呈先升后降的变化趋势;最大光量子效率（Fv/Fm）在处理第10天显著下降,此后随处理时间的延长逐渐回升至与对照一致水平。最大荧光（Fm）、非光化学淬灭（NPQ_Lss）、PSⅡ潜在活性（Fv/Fo）、光化学反应淬灭（qP_Lss）随处理时间的延长整体均呈上升趋势,初始荧光（Fo）呈下降趋势。说明榅桲在沙尘胁迫处理前期受非气孔因素的影响较大,沙尘胁迫导致榅桲叶片PSⅡ原初光能转换效率较低,对榅桲产生光抑制,导致Pn下降。而在处理后期,榅桲叶片主要通过增加qP_Lss、Fm、NPQ_Lss等来增强PSⅡ电子传递能力,提高非辐射性热耗散来消耗过剩光能,保护光合机构。     

盾壳霉抗菌核净菌株的诱导及其特性初步研究

为筛选可与菌核净配合防治作物菌核病的盾壳霉菌株,进行了紫外线辐射和药剂驯化试验,分别得到4个和2个盾壳霉抗菌核净突变菌株,并研究了其生物学特性。结果表明:除菌株D-1外,其余突变菌株生长速率(菌落直径57.00 ~62.75 mm,生物量6.38 ~8.63 mg/mL)均大于亲本菌株(菌落直径54.00 mm,生物量5.91 mg/mL);大部分突变菌株产孢量(对数值7.33 ~8.16)小于亲本菌株(8.40);菌核净对突变菌株的EC50值是亲本菌株的2.23 ~191.84倍;突变菌株D-3、U-6有微弱的几丁质酶活性,且除U-4外的突变菌株葡聚糖酶活性增强(亲本菌株8.96 U,突变菌株9.18 ~17.61 U)。综合分析,U-6菌株既有较高的葡聚糖酶活性又有几丁质酶活性,并能保持较快的生长速率,是值得开发的优良菌株。     

网络环境下高校图书馆员继续教育的思考

探讨了网络环境下我国高校图书馆员继续教育的必要性,分析了目前我国高校图书馆员继续教育存在的问题,提出了网络环境下高校图书馆员继续教育的培养途径。     

The Influence of Co-Suppressing Tomato 1-Aminocyclopropane-1-Carboxylic Acid Oxidase Ⅰ on the Expression of Fruit Ripening-Related and Pathogenesis-Related Protein Genes

The purpose of this study is to explore the influence of co-suppressing tomato ACC oxidase Ⅰ on the expression of fruit ripening-related and pathogenesis-related protein genes, and on the biosynthesis of endogenous ethylene and storage ability of fruits. Specific fragments of several fruit ripening-related and pathogenesis-related protein genes from tomato （Lycopersicon esculentum） were cloned, such as the l-aminocyclopropane-1-carboxylic acid oxidase 1 gene （LeAC01）, 1- aminocyclopropane-l-carboxylic acid oxidase 3 gene （LeAC03）, EIN3-binding F-box 1 gene （LeEBF1）, pathogenesis-related protein 1 gene （LePR1）, pathogenesis-related protein 5 gene （LePR5）, and pathogenesis-related protein osmotin precursor gene （LeNP24） by PCR or RT-PCR. Then these specific DNA fragments were used as probes to hybridize with the total RNAs extracted from the wild type tomato Ailsa Craig （AC＋＋） and the LeAC01 co-suppression tomatoes （V1187 and T4B）, respectively. At the same time, ethylene production measurement and storage experiment of tomato fruits were carded out. The hybridization results indicated that the expression of fruit ripening-related genes such as LeACO3 and LeEBF1, and pathogenesis-related protein genes such as LePR1, LePR5, and LeNP24, were reduced sharply, and the ethylene production in the fruits, wounded leaves decreased and the storage time of ripening fruits was prolonged, when the expression of LeACO1 gene in the transgenic tomato was suppressed. In the co-suppression tomatoes, the expression of fruit ripening-related and pathogenesis-related protein genes were restrained at different degrees, the biosynthesis of endogenous ethylene decreased and the storage ability of tomato fruits increased.     

锡林浩特草原区27种植物净光合速率影响因素的多因子分析

植物净光合速率的关键影响因子关系到草原生产力的波动和稳定性。实地测定锡林浩特草原22个样地27种共82株植物的光合指标和环境影响因子,采用Pearson相关性分析、多元回归分析、通径分析、决策系数分析等方法,分析各因子与草原植物净光合速率的关系。结果表明:锡林浩特草原区植物净光合速率与气孔导度、蒸腾速率呈极显著正相关,与胞间CO2浓度呈显著负相关;净光合速率与水分利用效率呈线性相关;在影响草原植物的环境因子中,净光合速率随大气相对湿度的增加而增大,而空气温度对净光合速率的影响并不显著;由通径分析可知,水分利用效率、蒸腾速率、气孔导度和大气相对湿度成为影响净光合速率的主要因素。决策系数表明,锡林浩特草原区植物的蒸腾速率、水分利用效率、气孔导度、胞间CO2浓度4个生理因子是净光合速率的主要决策变量,而环境参数中的空气温度和大气相对湿度,则成为净光合速率的限制性因素。影响草原植物净光合速率的因素有蒸腾速率、水分利用效率、气孔导度和大气相对湿度。     

假地豆响应缺磷胁迫的代谢衍生物分析

为探究假地豆(Desmodium heterocarpon)对缺磷胁迫的生理和代谢响应,本研究通过水培试验,分析了正常供磷(+P处理)和缺磷(-P处理)对假地豆生长及代谢物积累的影响。结果表明：缺磷胁迫降低了假地豆地上部干重和磷含量,但促进了根系生长。随后,代谢组共检测到假地豆叶片和根系的267个代谢物,可被分为12类。其中,叶片和根系的缺磷胁迫差异累积代谢物(DAMs)均为79个。缺磷处理导致假地豆叶片和根系的原花青素、槲皮素及其衍生物的积累显著增加,而2′-脱氧腺苷5′-单磷酸(dAMP)的积累显著减少。此外,缺磷处理使根系的8个有机酸和4个糖及醇类的积累显著增加。综上,假地豆通过促进根系生长和调整代谢物积累来提高对缺磷胁迫的适应性。本研究将为进一步解析假地豆适应缺磷胁迫的机理提供理论参考。     

用于汽车横向稳定性的模糊控制器的设计与研究

运用模糊控制理论在所建立的车辆非线性模型的基础上,设计了用于车辆横向稳定性的3种模糊控制器———基于横摆角速度的反馈控制、基于质心侧偏角的反馈控制以及基于这两个参数的联合反馈控制,并应用MATLAB/S imu link对所设计的3种模糊控制器分别进行了仿真分析,结果表明,3种控制器均能改善车辆的横向稳定性,能够提高车辆行驶的安全性,并且,联合控制的控制效果要优于单独控制。