杨小舟蛾发生规律与测报技术研究   总被引：12，自引：1，他引：11  

张军灵  宫建全 《陕西林业科技》1999,(4):1-3

杨上舟蛾［Ｍｉｃｒｏｍｅｌａｌｏｐｈａ ｔｒｏｇｌｏｄｙｔａ（Ｇｒａｅｓｅｒ）］中关中１年发生５代，以７、８月份的３、４代种群数量最大，危害最重。其天敌种类较多，多一年内种群数量消长影响较大，５～８月份降雨较多的年份发生较重。介绍了发育进度预测法，种群消长趋势指数预测法和黑光洒诱测法在杨小舟蛾测报中的应用。  相似文献   

疱疹病毒UL34基因及其编码蛋白的研究进展     

钟小容程安春  汪铭书陈孝跃 《中国兽医科技》2007,37(12):1099-1103

论述了疱疹病毒UL34基因的序列特点、编码蛋白结构特点、基本功能以及它与UL31蛋白、Us3蛋白、动力蛋白、核纤层蛋白的相互作用。表明，UL34基因对病毒的早期包装、成熟和出芽以及对UL31蛋白和核纤层蛋白在感染细胞中的正确定位都具有重要作用。  相似文献   

Genetic Variability in Phosphorus Acquisition and Utilization Efficiency from Sparingly Soluble P-Sources by Brassica Cultivars under P-Stress Environment     

M. S. Akhtar  Y. Oki  T. Adachi 《Journal of Agronomy and Crop Science》2008,194(5):380-392

Plants display an array of classical strategies to maximize phosphate (Pi) acquisition from sparingly soluble P sources. Acclimation to Pi-stress via elegant Pi-starvation induced (PSI) adjustments would reduce our current overreliance on expensive, polluting and non-renewable Pi-fertilizers. Nevertheless, differences in the ability of various species to solubilize sparingly soluble P-sources have been often evidenced; inter-cultivar variations are scarcely documented. Brassica is known as an effective, non-mycorrhizal user of sparingly soluble P-sources. Various growth parameters and biomass accumulation by genetically diverse Brassica cultivars were determined in four experiments using hydroponics and quartz sand culture media. Role of PSI root mediated pH changes, organic anions (OAs) exudation and altered root architecture in mobilization and acquisition of sparingly soluble P-forms [Jordan rock-P (RP) at 2 g l⁻¹ and Ca₃(PO₄)₂ (TCP) at 0.2 g l⁻¹ respectively] was investigated. Cultivars showed considerable genetic variations in biomass accumulation, various growth parameters and root–shoot ratio. Concentration and total uptake of P, specific absorption rate of P, P-transport rate and P-utilization efficiency (PUE) were also significantly (P < 0.001) different for various cultivars and their dry matter was significantly correlated with P-uptake [r = 0.94** (significant at 1% level)]. P-tolerant cultivars showed substantial decrease in solution media pH because of H⁺ efflux and exuded more carboxylates than low P-sensitive cultivars under P-starvation. P-uptake by cultivars increased linearly with decreasing pH. The amount and types of OAs exuded from the roots of P-starved plants differed from those of plants grown under P-sufficient environment. In split pot study, with TCP and RP supplied spatially separated from other nutrients, efficient cultivars were still able to mobilize RP and TCP more efficiently than inefficient cultivars. In rhizobox study, the elongation rates of primary roots decreased but the elongation rates of the branched zones of primary roots and the length of lateral roots increased under P-starvation. Tested cultivars showed genetic diversity in accessing, mobilization, acquisition and utilization of Pi from sparingly soluble P forms. An arrange marriage of plant traits can explain cultivar’s access to different forms of sparingly soluble P, and in addition to altered lateral root topology and enhanced P-uptake and PUE, enhanced H⁺ efflux and OAs exudation are key factors in Pi scavenging from extra cellular sparingly soluble P-forms.  相似文献   

花生多胺氧化酶的组织化学定位及显微拍摄     

吴东醒  何生根 《仲恺农业技术学院学报》1999,12(1):1-4

报告了花生幼苗（苗龄为６ｄ）中多胺氧化酶的组织化学定位，并就该酶定位研究中的摄影问题提出了几点看法  相似文献   

一种新的机顶盒缓存控制算法     

彭日回  郑善贤 《湖南农业大学学报(自然科学版)》1999,26(3)

结合视频点播系统中的一种存储与传输技术，分析并介绍了一种机顶盒功能的实现方案，研究了机顶盒视频点播缓存控制问题并提出了一种控制算法。  相似文献   

几种植物生长调控剂对油菜的生物学效应     

宋光泉  欧阳静仁 《仲恺农业技术学院学报》1999,12(3):44-49

以杂交油菜秦油２ 号和普通油菜中油８２１ 为试验材料，研究了在施硼砂的基础上喷施植物生长调控剂对油菜的生物学效应－ 结果表明：喷施多效唑（ＭＥＴ）使油菜叶片的气孔数、有效荚果数大幅度增加，对千粒重影响不明显，但使荚果内的表现粒数明显减少，尤其使秦油２ 号的成棵率极显著降低，且减产达显著水平；喷施８０２ 使油菜的有效荚果数和千粒重增加，但使叶片的气孔数和荚果内的表现粒数减少，增产效果不显著；喷施增产菌除使千粒重有增加的趋势外，但使中油８２１ 的成棵率极显著降低，增产效果也不显著  相似文献   

Protein extraction from defatted wheat germ by reverse micelles: Optimization of the forward extraction   总被引：4，自引：1，他引：3  

Xiao-Hong Sun  Ke-Xue Zhu  Hui-Ming Zhou   《Journal of Cereal Science》2008,48(3):829-835

In this work, the forward extraction of defatted wheat germ protein (DWGP) by reverse micelles was studied. The reverse micellar systems were formed by sulphosuccinic acid bis (2-ethylhexyl) ester sodium salt (AOT), isooctane and KCl solution. The effects of AOT concentration, pH, KCl concentration, extraction time, the amounts of defatted wheat germ flour (DWGF), W₀ (the molar ratio of water to surfactant, i.e. W₀ = [H₂O]/[AOT]) and temperature on the forward extraction efficiency of DWGP were tested. On the basis of single-factor experiments, the optimum extraction was achieved by response surface methodology (RSM). The experimental results lead to the conclusion that the highest forward extraction efficiency of DWGP was reached at the AOT concentration 0.06 g/mL, pH 8, KCl concentration 0.1 mol/L, time 30 min, the amounts of DWGF 0.500 g, W₀ 25 and temperature 36 °C. Under these conditions, the forward extraction efficiency of DWGP achieved 37%.  相似文献   

Predicting Carbon Stocks Following Reforestation of Pastures: A Sampling Scenario‐Based Approach for Testing the Utility of Field‐Measured and Remotely Derived Variables     

《Land Degradation \u0026amp; Development》2017,28(3):1122-1133

Reforestation of agricultural lands is an important means of restoring land and sequestering carbon (C). At large scales, the labour and costs of direct measurement of ecosystem responses can be prohibitive, making the development of models valuable. Here, we develop a new sampling scenario‐based modelling approach coupled with Bayesian model averaging to build predictive models for absolute values in mixed‐species woody plantings and differences from their adjacent pasture, for litter stocks, soil C stocks and soil C:N ratios. Modelling scenarios of increasing data availability and effort were tested. These included variables that could be derived without a site visit (e.g. location, climate and management) that were sampled in the adjacent pasture (e.g. soil C and nutrients) or were sampled in the environmental planting (e.g. vegetation, litter properties, soil C and nutrients). The predictive power of models varied considerably among C variables (litter stocks, soil C stocks and soil C:N ratios in tree plantings and their differences to their adjacent pastures) and the model scenarios used. The use of a sampling scenario‐based approach to building predictive models shows promise for monitoring changes in tree plantings, following reforestation. The approach could also be readily adapted to other contexts where sampling effort for predictor variables in models is a major potential limitation to model utilization. This study demonstrates the benefit of exploring scenarios of data availability during modelling and will be especially valuable where the sampling effort differs greatly among variables. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

FMDV OA/58病毒株VP3蛋白结构的模拟与分析   总被引：1，自引：1，他引：0  

周建华  丛国正  高闪电  常惠芸 《华北农学报》2008,23(6)

以口蹄疫病毒株OA／58 RNA为模板，反转录并扩增目的cDNA，然后与pMD18-T载体连接并转化JM109菌株，提取的重组质粒用凝胶电泳、PCR和BarnHⅠ、HindⅢ双酶切法鉴定。分析表明，口蹄疫病毒VP1、VP2、VP3和VP4在核苷酸水平上的变异率是无差异的（P〉0．05）；而它们在氨基酸水平上的变异率差异显著（P〈0．05）。该毒株与20株源于GenBank中的VP3氨基酸序列比较发现其保守区主要位于第1～24、26～35、37～43、45～57、61～122、124～173、175～209、211～220位。运用同源模建，OA／58 VP3蛋白三维空间结构可分为A，B，C3个结构区域。保守区氨基酸残基在维持VP3蛋白的空间构象和功能方面具有重要作用。  相似文献   

兔胚胎的一些与分离胚胎干细胞有关的生物学特征   总被引：6，自引：1，他引：5  

赖良学  郑瑞珍 《中国兽医学报》1998,18(4):351-354

为获得具有发育全能性的胚胎干细胞（ＥＳ细胞），对３日龄、３．５日龄和４日龄家兔胚胎的形态结构和免疫组化特征进行了观察。家兔胚胎的外围，不仅有透明带，还包有一层很厚的胶膜。３日龄兔胚为桑椹胚；３．５日龄胚胎已出现囊胚腔，囊胚腔较小，扩增内细胞团（ＩＣＭ）占据囊腔的１／２～２／３；４日龄为囊胚，囊腔扩大，ＩＣＭ与囊胚腔的体积比值缩小。桑椹胚的卵裂球和３．５日龄、４日龄胚胎的ＩＣＭ，以碱性磷酸酶染色和胚胎阶段特异性细胞表面抗原－１（ＳＳＥＡ－１）免疫荧光标记均呈强阳性，说明它们是由未分化的细胞构成。因此，从保证全能性的角度考虑，３日龄、３．５日龄和４日龄的家兔胚胎，均可用于ＥＳ细胞的分离。  相似文献