优质籼型不育系Q2A的选育   总被引：7，自引：3，他引：4  

李贤勇  王楚桃  李顺武  何永歆  杨勋毅  陈世全 《杂交水稻》2004,19(5):6-8

Q2A是重庆市农业科学研究所和重庆市种子公司用金23B×中九B的F2代与58B×Ⅱ-32B的F2代杂交,再用复交F2代与珍汕97A杂交引入野败型胞质育成的一个优质籼型三系不育系,2003年7月通过重庆市科学技术委员会组织的技术鉴定.该不育系异交习性好;可恢性好,配合力强;米质优(12项测试指标中有7项达部颁一级优质米标准,5项达二级标准);苗瘟3级,叶瘟3级,颈瘟7级,对苗瘟和叶瘟表现为中抗,颈瘟感病.其与成恢047配组育成的优质杂交中籼新组合Q优5号米质优,产量高,抗稻瘟病,2003年12月通过重庆市农作物品种审定.  相似文献   

Fire resistance performance on restrained high strength Q460 steel beams   总被引：2，自引：0，他引：2  

He Pingzhao  Wang Weiyong 《保鲜与加工》2015,(2):52-59

为了研究约束高强度Q460钢梁的抗火性能,在已有约束钢梁分析理论的基础上,引入残余应力,提出了约束钢梁的抗火性能分析方法,并采用普通强度约束钢梁试验数据对分析方法进行了验证。考虑高强度Q460钢材高温下力学性能参数,利用所提出的方法分析了约束高强度Q460钢梁的抗火性能,并与普通强度Q345钢梁进行了对比。对影响约束高强度Q460钢梁的抗火性能参数进行了分析,包括荷载比、残余应力、轴向约束刚度、转动约束刚度和受火方式等。研究表明：所提出的分析方法准确可靠,高强度Q460钢梁抗火性能与普通强度钢梁具有较大的区别,高强度Q460约束钢梁的抗火性能明显优于普通强度约束钢梁。荷载比、轴向约束刚度、转动约束刚度、受火方式对高强度Q460约束钢梁有较大影响。  相似文献   

西南地区主要类型土壤钾素有效性分析     

朱启红  伍钧 《农机化研究》2007,(7):153-157

通过测定西南地区主要类型土壤的基本农化性状、Q/I曲线、固钾率和酸提取钾来研究土壤钾素缓冲容量(PBCK),进而分析土壤钾素的有效性.试验结果表明,PBCK与土壤CEC、固钾率和酸提取均呈极显著正相关,因此可以用PECK来衡量土壤钾素有效性.  相似文献   

几种化学药剂防治日光温室番茄褪绿病毒病研究初报     

李娇娇  庄乾营  于毅  张秀霞  毛晓红  张安盛 《中国蔬菜》2016,1(8):60-63

为明确化学防治对日光温室番茄褪绿病毒病的防控效果,通过田间试验和室内PCR检测,评价应用化学杀虫剂防治Q型烟粉虱对日光温室番茄褪绿病毒病的防控作用,并研究病毒抑制剂对日光温室番茄褪绿病毒病的防控效果。试验结果表明,喷施杀虫剂防控Q型烟粉虱后日光温室番茄植株带毒率可降至3.00%。病毒抑制剂20%盐酸吗啉胍可湿性粉剂、0.5%葡聚烯糖可溶粉剂、30%毒氟磷可湿性粉剂在试验条件下对番茄褪绿病毒病的防治效果为44.08%~52.63%,可在一定程度上减轻番茄褪绿病毒病的危害。  相似文献   

长白山典型阔叶红松林土壤二氧化碳排放通量     

王琛瑞  吴劼  梁战备  黄国宏 《林业研究》2004,15(4):268-272

随着大气CO2浓度的升高,主要由其引起的温室效应与对生物新陈代谢的影响变得越来越显著。森林生态系统在全球碳循环中扮演着重要的角色。为了评估和理解森林土壤CO2通量及其随空气和土壤温度的季节和昼夜变化规律,我们在长白山北坡典型阔叶红松林内利用静态箱技术进行了原位观测。实验在整个生长季(6月初至9月末)昼夜进行,利用气相色谱进行气体分析。结果表明: 长白山阔叶红松林土壤是大气二氧化碳源,其CO2通量具有明显的季节和昼夜变化规律。通量的变化范围是(0.30-2.42)μmol穖-2穝-1,平均值为0.98μmol穖-2穝-1。土壤CO2排放的季节规律表明,土壤CO2通量的变化与气温和土壤温度的变化有关。CO2平均通量的最大值出现在7月((1.27±23%)μmol穖-2穝-1),最小值出现在9月((0.5±28%)μmol穖-2穝-1)。土壤CO2的昼夜波动与土壤温度变化有关,而在时间上滞后于温度的变化。森林下垫面土壤CO2通量与土壤温度显著相关,与6cm深度土层温度相关系数最大。基于气温和土壤温度计算的Q10值范围为2.09-3.40。图2表3参37。  相似文献   

黄土丘陵区白羊草与达乌里胡枝子混播草地土壤呼吸日变化特征   总被引：1，自引：0，他引：1  

陈吉  王京  高志娟  郭亚力  吴爱姣  徐炳成 《草业科学》2015,32(1):19-27

土壤呼吸是反映土壤质量和肥力性状的重要指标,阐明禾―豆混播草地土壤呼吸作用的变化规律及其影响因素,可以为准确评估混播草地的环境效应及响应提供依据。在2011和2012年6月份,采用动态密闭气室分析法,比较了白羊草(Bothriochloa ischaemum)与达乌里胡枝子(Lespedeza davurica)不同比例间作混播草地总土壤呼吸速率的日变化特征、混播植物贡献率以及温度敏感性等。结果表明,不同混播比例草地的总土壤呼吸速率日变化为单峰型曲线,峰值出现在12:00~14:00。总土壤呼吸速率日均值高低顺序为单播白羊草白羊草和达乌里胡枝子间作单播达乌里胡枝子。不同间作比例草地的总土壤呼吸速率与白昼气温相关显著(P0.05),而与5、10和15 cm土层白昼土壤温度关系不明显;单播条件下,白羊草草丛的土壤呼吸对温度的敏感性高于达乌里胡枝子;各草地土壤呼吸Q10值的变化范围为1.48~2.61,以单播白羊草最高,单播达乌里胡枝子和两者间作混播草地间无显著差异(P0.05)。  相似文献   

A Systematic Review and Meta‐Analysis of Phase I Inactivated Vaccines to Reduce Shedding of Coxiella burnetii From Sheep and Goats From Routes of Public Health Importance     

T. J. O'Neill  J. M. Sargeant  Z. Poljak 《Zoonoses and public health》2014,61(8):519-533

Q fever in humans and coxiellosis in livestock are both caused by Coxiella burnetii. The public health importance of vaccination against C. burnetii shedding from sheep and goats was evaluated using systematic review and meta‐analysis to provide evidence for policy direction to prevent potential zoonotic spread. Publications reporting shedding of C. burnetii in vaginal and uterine secretions, milk, placenta and faeces were included. A single observational (one goat) and seven experimental (four goat and three sheep) vaccine studies were included in the review. No relevant publications on other interventions were identified. Random effects meta‐analyses were performed for the risk of shedding in individuals in the control and vaccinated groups and for the mean difference in the level of bacterial shedding in sheep and goats stratified by age and previous exposure status. Limited data were available for further analytic evaluation. From the pooled analysis, an inactivated phase I vaccine significantly reduced the risk of shedding from uterine (RR = 0.10; 95%CI 0.05–0.20) secretions in previously sensitized goats. Individual studies reported significant risk reduction in milk (RR = 0.03; 95%CI 0.01–0.26), vaginal secretions (RR = 0.40; 95%CI 0.22–0.75) and faeces (RR = 0.79; 95%CI 0.63–0.97) from naïve goats. The pooled mean levels of bacteria shed from placental [mean difference (MD = ?5.24 Log₁₀; 95%CI ?6.75 to ?3.7)] and vaginal (MD = ?1.78 Log₁₀; 95%CI ?2.19 to ?1.38) routes were significantly decreased in vaccinated naïve goats compared with controls. Shedding through all other routes from vaccinated goats was not significantly different than shedding from control goats. No effect of vaccination was found on the risk of shedding or the mean level of shedding in vaccinated sheep compared with control sheep. Our conclusions are based on a limited amount of data with variable risk of systematic error.  相似文献   

39个牡丹品种的形态学分类研究     

韩雪源  张延龙  牛立新 《西北农林科技大学学报(自然科学版)》2014,42(9):128-136

【目的】探究牡丹品种分类的等级和标准,进而为其品种选育和资源研究提供参考。【方法】2013-03-05,观测了39个牡丹品种的26个质量和数量性状,首先对26个性状指标进行了R型聚类分析和主成分分析,然后根据R型聚类结果,去掉相关性大的指标,再对39个牡丹品种进行了Q型聚类分析。【结果】R型聚类结果显示,花瓣基部有无色斑与色斑颜色（r=0.766）,复叶长与复叶宽（r=0.659）的相关性较大,因此Q型聚类中不考虑色斑颜色和复叶宽2个性状。主成分分析结果表明：结实率、花瓣基部色斑情况、花期、花冠情况等12个性状的贡献率较大。Q型聚类结果显示,39个牡丹品种依据结实率、花瓣基部有无色斑和花期被分为3类：结实率高且花期较早的类群,如“赵粉”、“肉芙蓉”、“迎日红”、“粉中冠”等;结实率低且花瓣基部没有色斑的类群,如“状元红”、“绿香球”、“大胡红”、“珊瑚台”等;结实率低且花瓣基部有色斑的类群,如“红宝石”、“卷叶红”、“十八号”、“菱花湛露”等。【结论】筛选出对牡丹品种分类贡献较大的13个性状,得到可以作为其形态学分类依据的性状有结实率、花瓣基部有无色斑和花期。  相似文献   

Advance in receptor type protein tyrosine phosphatase Q     

HUANG Yong-hong  SHI Hui-mian  ZHOU Xiao-yan  XU Hong  LUO Zhi-jun  XU Fang-yun 《园艺学报》2015,31(7):1340-1344

Receptor type protein tyrosine phosphatase Q (PTPRQ) is an unusual protein tyrosine phosphatase that has intrinsic dephosphorylating activity for various phosphatidylinositiol and phospho-tyrosine substrates, especially the phosphatidylinositol activity. Recent data show that PTPRQ has an important role in various biological processes and is associated with some diseases. In this article, the structure and function of PTPRQ and the relationship between PTPRQ and diseases were briefly summarized.  相似文献   

Critical Phase Transition of the Two-dimensional Microcanonical Ising Model by Cellular Automata Q2R Method     

LI Li-qi  WANG Zong-fi 《保鲜与加工》2006,(11):115-118

The authors construct a microcanonical ensemble system and analyzes the phase change of the two-dimensional Ising model Cellular Automata Q2R/WQ2R method. The result indicates that the numerical value simulation can show the spontaneous magnetization of two-dimensional crystal lattice in isolated system. The authors have observed the critical phase transition phenomenon and gotten the critical energy. The simulation of three-dimensional Ising model can be grounded on the method that this article establishes.  相似文献