栓皮栎人工林冠层温度变化特征及其与微气象因子的关系

基于2011年栓皮栎主要生长季(5-8月)的冠层温度数据及同步观测得到的冠层微气象资料,分析了典型晴天和阴天条件下华北低丘山地栓皮栎人工林冠层温度(Tc)的变化特征及其与微气象因子的关系.结果表明:晴天日9:00-16:00,栓皮栎人工林林冠边界层处于不稳定状态,Tc比空气温度(Ta)平均高3.55℃;阴天日Tc的变化较晴天条件下平缓;Tc与Ta、净辐射(Rn)、相对湿度、风速等冠层微气象要素的复相关达极显著水平,其复相关系数为0.825;影响Tc的主要气象因子是Ta和Rn,二者对Tc的影响程度与天气状况有关.     

基于大尺度因子的小麦白粉病长期预测模型

根据1971—2008年全国小麦白粉病发生面积资料、1970—2008年大气环流特征量逐月资料及1970—2008年太平洋海温逐月资料,通过因子膨化、空间拓扑分析组合大气环流、海温因子,采用最优化处理、相关分析、相关稳定性检验、因子独立性检验等方法,筛选对小麦白粉病影响稳定、显著、独立的大气、海温因子,分别构建基于大气环流及太平洋海温的全国小麦白粉病发生面积率预报预测模型。利用2009—2010年资料对模型进行预测检验,经回代及预测检验,大气环流模型回代检验等级正确率为81.6%,2009、2010年等级预测正确率为100%,模型总体评价正确率为82.5%。太平洋海温模型回代检验等级正确率为78.95%,2009、2010年预测检验正确率为100%,模型总体评价正确率为80%。大气环流模型较太平洋海温模型总体评价准确率略高。     

施肥对小麦冠层温度的影响及其与生物学性状的关联

利用红外测温仪等研究了不同施肥处理对小麦冠层温度的影响。结果表明 :不同施肥处理可改变小麦基因型的冠层温度 ,对于同一基因型品种 ,养分胁迫越严重 ,冠层温度越高 ;籽粒灌浆期旗叶叶绿素含量、可溶性蛋白质含量、蒸腾速率、净光合速率及一些农艺性状与冠层温度呈显著负相关。这表明 ,优良的生物学性状和较低的冠层温度相联系 ,冠层温度的高低可能成为反映水、肥等栽培措施是否科学合理的便捷而较准确的指标     

夏季栾树群落冠层结构对其环境温湿度的调节作用

为探究栾树群落降温增湿作用与其冠层结构参数的相关性在一天中的变化趋势,于天气晴朗的夏季对北京奥林匹克森林公园栾树群落内部和对照点的温度、相对湿度、群落冠层结构参数进行了铡定.结果表明:栾树群落的郁闭度与叶面积指数、平均叶倾角呈显著相关,且叶面积指数与平均叶倾角呈显著相关;在夏季8:00-18:00,栾树群落可降低空气温度0.43～7.53℃,在12:00左右达到降温最大值,增加相对湿度1％ ～ 22％,且在10:00左右增湿作用最显著,而在18:00-次日8:00降温增湿效果不明显;9:00-12:00,郁闭度和叶面积指数显著影响栾树群落的降温增湿作用;12:00-14:00,仅郁闭度与降温增湿作用显著相关;直到18:00,郁闭度和叶面积指数共同决定了栾树群落的降温增湿作用.因此,影响栾树群落降温增湿作用的冠层结构参数在一天中随着时间的推移发生变化.     

基于单片机的温湿度控制系统的研究与应用

随着社会和科学技术的不断发展及工业控制自动化技术的不断深入,许多设备都实现了自动化操作。在设备自动化操作的过程中,工作人员为了保证设备的正常运行,要对设备的各项参数进行检查,而温度和湿度是各种设备的常用被控参数,对设备的温度和湿度进行控制是保证设备正常运行的前提条件。用单片机对温度和湿度参数进行控制,对设备的正常运行具有重要意义。本文对基于单片机的温湿度控制系统的研究与应用进行探讨。本文给出了一套温湿度控制系统的设计方案,并对该系统的结构和硬件系统及软件设计进行了详细介绍。此外,对该温湿度控制系统的各结构所运用的设备名称进行了阐述,软件的设计和流程在文中也有涉及。     

小麦赤霉病的药剂防治指标模型

经过推导,得出小麦赤霉病的两类药剂防治指标模型．在保证品质、收支有余的条件下,第一类模型附加产投比较佳、净收益最佳原则,第二类模型附加产投比最佳原则．灵敏度分析和合理性分析证明了模型的正确性．模型可做为小麦赤霉病药剂防治的决策工具．同时,给出了两类模型的BASIC计算程序．     

小麦籽粒灌浆期冠层温度分异动态及其与源库活性的关系

选用18个小麦品种为材料,从开花期到乳熟末期,对品种间冠层温度进行比较,并对冠层温度与旗叶源活性指标(丙二醛含量、蔗糖磷酸合成酶活性、净光合速率、叶绿素含量、单茎有效绿叶数、顶三叶绿叶面积比率)和库活性指标(籽粒蔗糖合成酶活性、ADPG焦磷酸化酶活性、可溶性蛋白含量、籽粒淀粉积累速率)进行相关分析.结果表明:小麦品种间冠层温度在各生育时期均有显著性差异,且随灌浆进程的推进差异程度越来越大;从乳熟初期到乳熟末期,冠层温度与各源活性指标的相关系数均有增加的趋势,并在乳熟后期和末期均达到极显著水平;冠层温度与各库活性指标的相关系数在乳熟末期均达到显著水平.研究发现,小麦籽粒灌浆期品种间冠层温度差异随生育期推进而愈加显著,冠层温度与源库活性的关系以乳熟后期和末期最密切.     

中国稻飞虱发生的大气环流指示指标

根据1971—2010年稻飞虱发生面积率和发生程度资料,构建综合反映稻飞虱发生为害的因子,定义为稻飞虱发生指数。基于因子膨化方法对74项大气环流特征量进行合理扩充,采用相关分析等方法研究当年2月初、4月初、6月初对全国稻飞虱发生面积率等级、发生程度等级、发生指数等级具有指示意义的大气环流因子的筛选及其相应等级指标的构建。结果表明:影响稻飞虱发生面积率等级的指示因子为西太平洋副高面积指数、南海副高脊线、北半球极涡强度指数、印缅槽,影响稻飞虱发生程度等级的指示因子为太平洋副高北界、亚洲纬向环流指数、东亚槽强度、太阳黑子数,影响稻飞虱发生指数等级的指示因子为北半球副高强度指数、北半球极涡强度指数、大西洋欧洲环流型指数、西藏高原指数。不同指示因子的量值在稻飞虱轻、偏轻、偏重和重发生时差异性显著;建立的稻飞虱发生等级的大气环流指示指标,经历史发生情况检验,对稻飞虱发生等级具有很好的指示效应,可为稻飞虱中长期预测预报提供科学依据。     

基于经验法则的小麦白粉病气候年型分析

温湿度条件是影响小麦白粉病发生流行的关键气象要素.应用河北省主麦区1987-2010年小麦白粉病资料和相应气象资料,利用合成分析和秩相关分析,筛选出影响小麦白粉病流行的关键气象因子;根据经验法则,利用小麦白粉病流行阶段的温度距平和湿度距平判别白粉病流行程度,并确定了白粉病流行的气候年型与指标.经历史回代,判别小麦白粉病流行程度准确率为84％,并进行了2011年、2012年的外延指标判别,准确率达100％,综合判断准确率在85％以上.该研究结果可为小麦白粉病影响评估与长期预报提供科学依据.     

不同时间尺度下华北落叶松人工林冠层蒸腾与环境因子的关系

在半干旱区连续2年监测华北落叶松(Larix principis-rupprechtii)的树干液流、气象因子和土壤体积含水量,分析不同时间尺度下人工林冠层蒸腾与环境因子的关系。结果表明：不同时间尺度下,华北落叶松人工林冠层蒸腾的季节变化均呈单峰曲线,即先增大后减小的趋势;2016年、2017年日蒸腾量分别为1.58 mm/d和1.71 mm/d,生长季蒸腾总量分别为241.30 mm和260.97 mm。在日尺度下,气温、太阳辐射强度和饱和水汽压差是影响华北落叶松人工林冠层蒸腾主要环境因子;月尺度下,气温、风速、降水和土壤水分是冠层蒸腾的主要影响因子;冠层蒸腾与降水、大气相对湿度的相关关系由日尺度下的负相关到月尺度的正相关,相关性增强。总体来看,随时间尺度由小到大,气温、风速、大气相对湿度、降水、土壤水分对冠层蒸腾的影响作用增大,而太阳辐射强度、饱和水汽压差的作用减弱;在未来增温增雨趋势下,研究区生长季将延长,华北落叶松人工林冠层蒸腾量可能会加大。     

小麦抗白粉病相关基因的转化

利用玉米花青素苷合成调节基因C1-Lc作为报告基因, 通过瞬间表达后愈伤组织表面红色斑点的统计分析, 优化了小麦幼胚愈伤组织的基因枪转化参数。小麦Beclin1类似基因TaTBL和硫代硫酸硫转移酶基因TaTST是2个在白粉菌诱导条件下具有增强表达特性的抗病相关基因。本实验进一步利用基因枪将ubi强启动子控制下的2个基因导入到小麦品种扬麦158的幼胚愈伤组织细胞中, 使用除草剂经两轮选择培养基上的筛选和再生获得抗性植株, 进一步通过抗性植株的PCR分析获得转TaTBL基因植株5株, 转TaTST基因植株6株。转基因植株离体叶片的人工接种实验表明, 外源基因的导入不同程度上增强了植株的白粉病抗性, 表现为延缓了白粉菌的发育。利用玉米花青素苷合成调节基因C1-Lc作为报告基因,通过瞬间表达后愈伤组织表面红色斑点的统计分析,优化了小麦幼胚愈伤组织的基因枪转化参数。小麦Beclin1类似基因TaTBL和硫代硫酸硫转移酶基因TaTST是两个在白粉菌诱导条件下具有增强表达特性的抗病相关基因。本实验进一步利用基因枪将ubi强启动子控制下的两个基因导入到小麦品种扬麦158的幼胚愈伤组织细胞中,使用除草剂经两轮选择培养基上的筛选和再生获得抗性植株,进一步通过抗性植株的PCR分析获得转TaTBL基因植株5株,转TaTST基因植株6株。转基因植株离体叶片的人工接种实验表明,外源基因的导入不同程度上增强了植株的白粉病抗性,表现为延缓了白粉菌的发育。     

基于冠层温湿度模型的日光温室黄瓜霜霉病预警方法

利用温室环境参数构建室内微环境模拟模型,并结合温室病害模型进行预警,便于开展病害生态防治,以减少农药使用,从而保护温室生态环境和保证农产品质量安全.本文利用温室内能量守恒原理和水分平衡原理,构建了日光温室冠层叶片温度和空气相对湿度模拟模型.叶片温度模拟模型考虑了温室内植物与墙体、土壤、覆盖物之间的辐射热交换,以及室内净辐射、叶片蒸腾作用引起的能量变化;相对湿度模拟模型综合了温室内叶片蒸腾、土壤蒸发、覆盖物与叶面的水汽凝结引起的水分变化.将温湿度估计模型输出值作为参数,输入黄瓜霜霉病初侵染和潜育期预警模型中,估计黄瓜霜霉病发病日期,并与田间观测的实际发病日期比较.试验选取2014年9月和10月的温湿度监测数据进行模型验证,冠层叶片温度实际值与模拟值的均方根偏差（RMSD)分别为0.016和0.024 ℃,空气相对湿度实际值与模拟值的RMSD分别为0.15%和0.13%.结合温湿度估计模型结果表明,黄瓜病害预警系统预测黄瓜霜霉病发病日期与田间调查发病日期相吻合.本研究可为黄瓜日光温室病害预警模型及系统构建提供微环境数据支持.     

Development of wheat near-isogenic lines for powdery mildew resistance

Using three Chinese wheat cultivars, Bainong 3217, Beijing 837 and Laizhou 953, as recurrent parents, 33 near-isogenic lines (NILs) carrying 22 powdery mildew resistance genes (Pm1c, Pm2, Pm4b, Pm12, Pm13, Pm16, Pm20, Pm21, Pm23, and 13 undocumented genes) were developed. All NILs had no significant difference to their recurrent parents in the investigated traits of agronomic importance. The results of AFLP analysis indicated Jaccards genetic similarity of the NILs with their recurrent parents varied from 0.96 to 0.98, and confirmed that the NILs had high genetic similarity with their recurrent parents. The resistance to powdery mildew was stably expressed by the relevant NILs. Eleven of the NILs were tested using molecular markers linked to the resistance genes Pm1c, Pm4b, Pm13, Pm21, PmP, PmE, PmPS5A, PmPS5B, PmY39, PmY150, and PmH, and they were all found to carry the targeted genes. The potential application of these NILs in gene discovery is discussed.     

Competitive performance of transgenic wheat resistant to powdery mildew

Genetically modified (GM) plants offer an ideal model system to study the influence of single genes that confer constitutive resistance to pathogens on the ecological behaviour of plants. We used phytometers to study competitive interactions between GM lines of spring wheat Triticum aestivum carrying such genes and control lines. We hypothesized that competitive performance of GM lines would be reduced due to enhanced transgene expression under pathogen levels typically encountered in the field. The transgenes pm3b from wheat (resistance against powdery mildew Blumeria graminis) or chitinase and glucanase genes from barley (resistance against fungi in general) were introduced with the ubiquitin promoter from maize (pm3b and chitinase genes) or the actin promoter from rice (glucanase gene). Phytometers of 15 transgenic and non-transgenic wheat lines were transplanted as seedlings into plots sown with the same 15 lines as competitive environments and subject to two soil nutrient levels. Pm3b lines had reduced mildew incidence compared with control lines. Chitinase and chitinase/glucanase lines showed the same high resistance to mildew as their control in low-nutrient treatment and slightly lower mildew rates than the control in high-nutrient environment. Pm3b lines were weaker competitors than control lines. This resulted in reduced yield and seed number. The Pm3b line with the highest transgene expression had 53.2% lower yield than the control whereas the Pm3b line which segregated in resistance and had higher mildew rates showed only minor costs under competition. The line expressing both chitinase and glucanase genes also showed reduced yield and seed number under competition compared with its control. Our results suggest that single transgenes conferring constitutive resistance to pathogens can have ecological costs and can weaken plant competitiveness even in the presence of the pathogen. The magnitude of these costs appears related to the degree of expression of the transgenes.     

部分小麦近缘物种材料的白粉病抗性鉴定

鉴定了170份小麦近缘物种材料苗期对北京地区流行的小麦白粉菌小种的抗性表现,包括引自美国和欧洲的斯卑尔脱小麦81份,密穗小麦27份,中国的西藏半野生小麦4份,和引自 CIMMYT 的人工合成六倍体小麦58份。结果表明,3份斯卑尔脱小麦表现抗病,它们是瑞士品种 Hubel 和 Lueg 以及德国的原始品种69Z6.245(编号 PI348085)。人工合成六倍体小麦中有19份材料表现高抗至免疫。密穗小麦材料中有2份(即美国材料 DN-2263和 Coda)表现抗病。4份西藏半野生小麦苗期都不抗小麦白粉病。     

对CIMMYT小麦品种抗白粉病的鉴定简报

1999～2001年连续2年,对 CIMMYT 提供的165份小麦品种进行成株期田间人工诱发抗白粉病鉴定。鉴定病圃设在本院试验农场,面积为200m~2。人工诱发鉴定圃的接种菌源,以上年度采集并保存的当地白粉病菌菌株,先在温室的感病品种8017-2上繁殖,2月下旬将带有大量分生孢子堆的病株移植到病圃的二个诱发行中间,每距33cm 种植2株病株。由于病株上有大量分生孢子,使诱发行麦株迅速受侵染且严重发病,形成充分接种菌源,保证对供鉴品种的重复侵染,以诱发供试小麦材料成株期感染发病。     

Inheritance of partial resistance to powdery mildew in spring wheat

Summary Four spring wheat (Triticum aestivum L.) cultivars exhibiting partial resistance to powdery mildew induced by Erysiphe graminis f.sp. tritici were crossed to a common susceptible cultivar to study the inheritance of resistance. The genetic parameters contributing to resistance were estimated by generation means analyses. Additive gene action was the most important genetic component of variation among generation means in all four crosses. Additive by additive effects were significant in one cross and both additive by additive and additive by dominance effects were significant in another. Dominance effects were not significant. The F2/F3 correlations in three crosses ranged from 0.27 to 0.43. Three additional crosses among resistant cultivars were employed to study the effectiveness of selection in improving resistance. By selecting the most resistant plants from the F2 and evaluating the progenies in the F4, increases in resistance ranging from 21% to 31% were obtained. In all crosses, there was transgressive segregation in both directions indicating that the genes conferring resistance to these cultivars differ and exhibit additive effects.     

Susceptibility to powdery mildew of wheat plants deficient in copper

Summary Wheat plants were grown in deep pots at three levels of copper nutrition in an open-sided glasshouse where they were subject to natural infection by powdery mildew. Plant growth and the degree of infection of each leaf were assessed weekly throughout the life of the plants.During the middle phase of growth especially — from tillering to anthesis — severity of infection of leaves was decreased by increasing the level of copper supply. Stems of copper-deficient plants were also severely infected. In these plants serious disease was sustained until final harvest. The results are discussed in relation to known and speculative roles of copper in plants.     

Glucose, and not sucrose, is transported from wheat to wheat powdery mildew

The main host carbon energy source transferred from wheat leaves (Triticum aestivum L.) to wheat powdery mildew (Erysiphe graminis f.sp. tritici) has been investigated in three ways. When the uptake of sugars by isolated mycelial suspensions was examined, the uptake rate for glucose was considerably higher than that for a range of other solutes. Analysis by high-performance liquid chromatography of leaf and mycelial extracts following uptake of sugars into infected leaf pieces confirmed that sucrose was rapidly hydrolyzed in the leaf; no sucrose or fructose could be detected in mycelial extracts. Furthermore, studies of the uptake of asymmetrically labelled sucrose indicated that this sugar is cleaved prior to uptake by the pathogen. Thus several lines of evidence show that glucose, and not sucrose, is the major carbon energy source transferred from host to fungal mycelium. Received: 11 November 1998 / Accepted: 18 January 1999