Synthesis of benzylaminopyrimidines and their fungicidal activities against wheat brown rust and barley powdery mildew

Members of a new class of fungicide containing benzylaminopyrimidine as a core structure were synthesized and their fungicidal potencies against wheat brown rust, Puccinia recondita, and barley powdery mildew, Erysiphe graminis, were assessed. Among these fungicides, N-(fluoroalkoxy or fluorophenoxybenzyl)-4-pyrimidinamines showed notable preventive activities. The potency of the new pyrimidines was increased when a difluoromethoxy or tetrafluorophenoxy group was introduced at the 4- or 3-position of the phenyl moiety and a methyl or ethyl group was introduced at the benzyl position. Structure–activity relationships are discussed. © 1998 Society of Chemical Industry     

The effect of fungicide dose on the composition of laboratory populations of barley powdery mildew

The effect of the use of different doses of the fungicide fenpropimorph on populations of barley powdery mildew Blumeria ( Erysiphe ) graminis f. sp. hordei was investigated in a laboratory selection experiment. A sample from the Danish aerial population of powdery mildew was split into populations, and these were kept separately for 31 generations on susceptible barley seedlings treated with fungicide at two concentrations, as well as on a control. Samples from these populations were tested for their resistance to fenpropimorph and their virulence spectra. There was a large amount of environmental variation in the ED₅₀ values used to measure fungicide resistance. In both treated populations, the average level of fungicide resistance increased, this increase being faster and greater in the population treated with the high dose. The diversity of pathotypes of the treated populations decreased, with the decline being more rapid in the population treated with the high dose, where one pathotype dominated the population after 31 generations. This pathotype was apparently not the fittest in the population treated with the low dose. This implies that knowledge of ED₅₀ is not sufficient to predict pathotype evolution under different fungicide treatments. The dominant pathotype in the high-dose treatment may not have been clonal, as there was evidence of two levels of fungicide resistance. The large environmental variation observed in estimated ED₅₀ values for resistance towards fenpropimorph may help to explain why this resistance has evolved at a slower rate than resistance towards other fungicides.     

The effect of fungal density on fungicide dose–response curves in barley powdery mildew (Erysiphe graminis f.sp. hordei)

The effect of inoculation density on fungicide dose–response curves and the estimated ED₅₀ value (the fungicide concentration needed to halve the infected leaf area relative to the infected area of leaves that had not been treated with a fungicide) were investigated theoretically, and predictions were tested experimentally using powdery mildew of barley ( Erysiphe graminis [syn. Blumeria graminis ] f.sp. hordei ). A host leaf was assumed to consist of a number of independent compartments, in each of which only a single fungal spore could germinate successfully. The number of fungal spores landing in a compartment was assumed to be Poisson-distributed. The spores were assumed to vary in their sensitivity toward a fungicide, and the sensitivity of the spore population was assumed to be normally distributed around a mean sensitivity. Under these assumptions, the ED₅₀ value was shown to be a positively biased estimate of the mean sensitivity in the fungal population, and the bias increased with inoculum density. Consequently, the estimated ED₅₀ value is expected to vary between experiments and laboratories if the inoculation density varies over a considerable range. The correlation between inoculum density and estimated ED₅₀ value is expected to be strongest when the assayed fungal population consists of several genotypes differing in sensitivity. This expectation was tested by estimating the ED₅₀ values for one barley powdery mildew isolate at different inoculation densities for three different fungicides. These ED₅₀ values were positively correlated strongly with the inoculum density for fenpropimorph and more weakly for triadimenol, whereas no correlation was observed for propiconazole.     

Mining wild barley for powdery mildew resistance

Powdery mildew, caused by Blumeria graminis f. sp. hordei (Bgh), is a worldwide disease problem on barley (Hordeum vulgare) with potentially severe impact on yield. Historically, resistance genes have been identified chiefly from cultivated lines and landraces; however, wild barley (H. vulgare subsp. spontaneum) accessions have proven to be extraordinarily rich sources of powdery mildew resistance. This study describes the characterization of a collection of 316 wild barley accessions, known as the Wild Barley Diversity Collection (WBDC), for resistance to powdery mildew and the genetic location of powdery mildew resistance loci. The WBDC was phenotyped for reaction to 40 different Bgh isolates at the seedling stage and genotyped with 10 508 molecular markers. Accessions resistant to all 40 isolates of Bgh were not found; however, three accessions (WBDC 053, 085 and 089) exhibited resistance to 38 of the isolates. Gene postulation analyses revealed that many accessions, while resistant, contained none of the 12 genes present in the Pallas near‐isogenic lines Mla1, Mla3, Mla6, Mla7, Mla9, Mla12, Mla13, Mlk1, MlLa, Mlg, Mlat and Ml(Ru2), suggesting that the accessions carry novel genes or gene combinations. A genome‐wide association study of powdery mildew resistance in the WBDC identified 21 significant marker‐trait associations that resolved into 15 quantitative trait loci. Seven of these loci have not been previously associated with powdery mildew resistance. Taken together, these results demonstrate that the WBDC is a rich source of powdery mildew resistance, and provide genetic tools for incorporating the resistance into barley breeding programmes.     

不同诱抗剂防治豌豆白粉病的效果及对防御酶的影响

本文研究了4种诱抗剂防治豌豆白粉病的效果及其诱导豌豆叶片防御酶活性变化。结果表明,用不同诱抗剂进行诱导处理后第7天,对豌豆白粉病防效为16.25%~52.18%,效果最好的处理为0.1%S-诱抗素,平均防效为52.18%,处理后第10天,防效上升到20.59%~56.43%,效果最好的仍为0.1%S-诱抗素;喷施诱抗剂后增产效果明显,不同处理平均增产幅度在0.77%~12.54%之间;诱导后显著提高了抗性相关防御酶POD活性,其中0.1%S-诱抗素处理POD酶活性最高,但却降低了CAT酶活性。     

小麦品种多样性对白粉病及产量和蛋白质的影响

 对品种多样性控制小麦白粉病的效果以及对产量和蛋白质的影响进行了研究,为利用品种多样性控制白粉病提供理论依据和技术支持。采用SSR技术分析5个小麦品种的亲缘关系;2008年和2009年按组合所含品种数为2、3、4和5个进行组合,在田间种植混种组合和单播小区,人工接种白粉菌,比较各小区中小麦白粉病的AUDPC值、产量和蛋白质变化。结果表明,5个品种亲缘关系相对较近;2个品种混合时以抗感搭配较好,随着抗病品种比例增加控病效果增强;2008年混合种植中有防治效果的组合占54.55%,相对防效为10.02%~47.58%,2009年有防治效果的组合占23.08%,相对防效在1.85% 到18.96 % 之间;在适当的组合中,如京冬8号/轮选987、京双16/京411/京冬8号对小麦白粉病有控制效果,混种不会影响产量和蛋白质含量;当有大量能克服本地品种抗性的外来菌源时混合种植的控病效果降低。品种多样性可以用做防治小麦白粉病的一项措施。     

多功能生物制剂对黄瓜白粉病的防治效应

通过盆栽和田间药效试验,研究了多功能生物制剂多霸2对黄瓜白粉病的防治效应。盆栽试验结果表明,先施用多霸2的100、200倍液后接种病原菌,可显著提高黄瓜的抗病能力,降低发病率,防效达到72.0%和69.2%,差异极显著(P<0.01);先接种后喷药多霸2的100、200倍液,在一定程度上能抑制病原菌的扩展,也具有防治作用,相对防效达到26.5%和23.1%,差异显著(P<0.05)。田间调查表明,在黄瓜苗期开始施用或未发病前施用多功能制剂,能有效预防白粉病的发生,具有很好的防治效应。多霸2的100、200倍液对黄瓜白粉病的防效与清水对照和常用药剂粉锈宁相比,差异都达到显著或极显著水平。其中,多霸2的100倍液使用效果最好,优于200倍液。     

61个小麦后备品种对白粉病的抗性分析及抗病基因推导

为明确中国61个小麦后备品种对白粉病的抗性水平及其抗病基因,将2016年从黄淮海冬麦区、长江中下游冬麦区及东北春麦区的9个市采集分离的269株单孢子堆白粉病菌,分别接种于61个小麦后备品种进行抗性测定;用NTSYSpc 2.10e软件对供试品种表型数据进行聚类分析;用35株鉴别菌株对29个含已知抗白粉病基因小麦材料和61个小麦后备品种进行鉴别,比较其抗谱并推导61个小麦后备品种所含抗白粉病基因。结果显示,61个小麦后备品种间的抗谱存在明显差异,国豪麦5号和7号、BL5008、绵麦系列、黔麦系列、楚麦16号、内麦101和366等18个品种抗谱较宽,抗性频率均大于97.0%;泰科麦5303、邯11-5272和临Y8222等10个品种的抗性频率在42.0%～56.1%之间;郑麦0943等33个品种的抗性频率小于37.9%。聚类分析可将61个小麦后备品种分成5大类,第I类有11个品种,其中8个品种的抗性频率在42.0%～56.1%之间;第II类和第III类共30个品种,抗性频率均小于32.7%;第IV类有2个品种,抗性频率分别为53.5%和53.2%,第V类有18个品种,抗性频率均大于97.0%;聚类显示来自于同一地区且抗性频率相近的品种具有相似或相近的抗性遗传背景。本研究推导出21个小麦后备品种含抗病Pm基因,其中,邯11-5272含有Pm30,安科1503含有Pm2、Pm5a、Pm6、Pm19和Pm30,临Y8222含有Pm5a、Pm6、Pm19和Pm30,云154-15含有Pm5a、Pm6、Pm7、Pm19和Pm2+ta,泰科麦5303等6个品种含有Pm2和Pm30,华麦7号等5个品种含有Pm5a、Pm6和Pm19,扬麦24号等6个品种含有Pm5a、Pm6、Pm19和Pm2+ta。研究表明,54.1%的小麦后备品种对白粉病菌群的抗性频率小于37.9%,存在适宜条件下小麦白粉病暴发流行的风险,因此这些小麦后备品种推广种植时需加强病害预警和监测。     

植物源农药对刺梨白粉病田间防效及其品质和产量的影响

为筛选有效防治刺梨白粉病的植物源农药, 以‘贵农5号’为试材, 研究5种植物源农药对刺梨白粉病的防治效果以及对果实品质及产量的影响。结果表明, 连续两次施药后, 植物源农药对刺梨白粉病防效良好, 能提高果实品质, 增加产量; 其中, 0.5%大黄素甲醚AS、0.5%小檗碱AS药后7 d防效分别为88.09%、85.82%, 药后14 d 防效分别为82.07%、83.27%, 与化学药剂相当; 0.5%大黄素甲醚AS处理组果实品质最佳, 相对化学药剂处理果实中可溶性固形物、可溶性糖、维生素C含量分别提高22.11%、24.58%、11.26%, 抗氧化能力增强6.72%; 6%大蒜素EC、0.5%大黄素甲醚AS、0.5%小檗碱AS处理与化学药剂25%嘧菌酯SC处理相比产量无明显差异, 增产作用相当, 增产率分别为143.02%、152.29%、148.38%; 从对刺梨白粉病田间防治效果、果实品质、产量等因素综合考虑, 0.5%大黄素甲醚AS是防治刺梨白粉病的最佳植物源农药。     

小麦白粉病与温度的定量关系研究

温度对小麦白粉病影响试验的结果表明,此病害适宜发生的温度为15～20℃,低于10℃或高于25℃对该病有明显抑制作用。当温度高于26℃时,试验显示随着温度的升高,终止小麦白粉病病程的时间缩短,据此建立了不同温度(x)与相应终止病程的时间(y)的关系模型为y=21 900e^{-0.303 5x}(χ²=1.65<χ²_0.05,7=14.07)。同时,根据高温区病害的严重度(y)与温度(x)的试验数据,建立了其关系模型为:y=-3.00x+76.60(r²=0.922 1^**),由此计算获得了连续10 d(一个病程时间)温度为25.53℃即可终止此病害的病程。该试验结果将为小麦白粉病的越夏区划提供基础数据。     

小麦白粉病反应型和产孢量的关系

利用小麦的6个品种及小麦白粉菌的3个小种研究了小麦苗期白粉病反应型与产孢量之间的关系。分别用累积单斑产孢量(LBSY)、累积单位面积产孢量(LASY)与反应型组建了反应型-产孢量关系模型:Y_1=exp(1.7178×lnX 0.0256X-2.484)(LBSY法);Y_2=exp(1.5168×lnX 0.052X-2.309)(LASY法)(X为反应型,Y为产孢系数)。通过LBSY方法获得反应型0,1,2,3~-,3,3~ ,4~-,4所对应的产孢系数分别为0,0.09,0.29,0.49,0.60,0.71,0.96,1。     

甘肃省主要小麦生产品种及高代品系的抗白粉基因推导

［目的］ 采用基因推导法对目前甘肃省小麦主要生产品种及高代品系进行抗白粉基因分析,为甘肃省白粉病的抗病育种和品种使用及布局提供依据。［方法］ 利用21个小麦白粉菌株,结合品种系谱对甘肃14个小麦生产品种及28个高代品系进行抗白粉基因推导。［结果］ 14个生产品种中,1个含Pm8,1个含Pm4b,4个含未知抗病基因,其余8个对所有供试菌株全部表现感病;28个高代品系中,5个含Pm8〖STBZ〗,2个含Pm〖STBX〗3〖STBZ〗a,1个含Pm〖STBX〗4〖STBZ〗b,1个含Pm〖STBX〗30〖STBZ〗,5个含未知抗病基因,其余14个对所有供试菌株全部表现感病。［结论］ 目前甘肃小麦生产品种及高代品系中缺乏抗白粉病基因,一旦条件适宜,小麦白粉病在甘肃地区极易发生和流行,应该引起生产管理部门和育种专家的注意和重视。     

我国主要小麦推广品种抗白粉病基因的分子检测

为了解我国主要小麦推广品种抗白粉病基因的分布与利用情况,采用分子遗传标记技术,对我国代表性小麦推广品种中Pm2、Pm3、Pm4、Pm6、Pm8、Pm13、Pm21、Pm23等抗病基因进行了分析。结果表明,几乎所有供试品种均含有上述1个或多个抗病基因,部分小麦品种同时携带有4～6个抗病基因;其中携带Pm3、Pm2、Pm8、Pm23和Pm4的频率最高,而Pm13和Pm21等应用潜力较大的抗病基因只分布在少部分品种中。在今后的工作中应该加强新抗源的鉴定和应用的力度。     

南瓜品种对白粉病的抗病性与叶绿素含量和气孔密度的相关性

不同南瓜品种对白粉病的抗病性测定结果表明,供试的10个南瓜品种中存在明显的抗病性差异,品种三星、红栗、甜栗表现为高抗;品种二星、日本、金钩、京域表现为抗病;品种光板、天然、红福表现为感病。品种抗病性与南瓜叶片叶绿素含量的高低和叶片气孔数量关系的研究结果表明,南瓜叶片中叶绿素的含量与南瓜品种对白粉病的抗性呈正相关,而气孔密度与抗病性呈负相关。     

防治西葫芦和黄瓜白粉病的生物制剂的筛选

瓜类白粉病是蔬菜上的重要病害之一,为加大对该病害的生物防治力度,本研究采用课题组研发的1×109cfu/g玫瑰黄链霉菌水剂和10亿芽胞/g枯草芽胞杆菌悬浮剂以及市场上常用的枯草芽胞杆菌、哈茨木霉菌、寡雄腐霉、武夷菌素、多抗霉素等多种生物制剂进行田间药效试验,比较几种生物制剂的防治效果。结果表明,供试生物制剂对西葫芦白粉病的防效为57.65%~84.98%,其中3%多抗霉素水剂600倍液的防效最好,为84.98%,且具有明显的促生长作用,增产率达12.65%。其次为1 000亿芽胞/g枯草芽胞杆菌可湿性粉剂(武汉天惠)400倍液、2%武夷菌素水剂600倍液和3×108 cfu/g哈茨木霉菌可湿性粉剂300倍液,可作为西葫芦白粉病防治的选用药剂。1×109 cfu/g玫瑰黄链霉菌水剂对西葫芦和黄瓜白粉病均具有较好的防效,分别为78.68%和73.59%,具有开发和应用的市场价值。     

2011—2014年河南省小麦白粉菌群体毒性结构分析

<正>小麦白粉病是小麦生产上的重要病害,在我国各主要麦区均有发生。上世纪70年代后期以来,随着小麦矮秆品种的推广、水肥条件的改善和小麦白粉病单一抗源的利用,再加上小麦白粉菌生理小种高度变异等因素的影响,导致小麦白粉病的发病面积和危害程度维持在一个较高的水平。国际上普遍采用的是基于小麦     

两个陇南冬小麦品种苗期抗白粉病性遗传分析

2006-2009年,以甘肃陇南生产品种陇鉴9343、陇鉴9811作母本,铭贤169作父本进行杂交,F2代材料苗期分别接种白粉菌单孢菌系E05、E09进行抗性遗传分析,结果表明:对陇鉴9343组合,接种E05和E09,F2代植株抗感分离比分别为65:217和65:154,经卡方测验符合理论比1:3。对陇鉴9811组合,接种E05和E09,F2代植株抗感分离比分别为52:166和87:314,也符合理论1:3的比率。据此推知陇鉴9343、陇鉴9811对E05和E09的抗性均由1对隐性抗性基因控制。     

一体化智能孢子捕捉系统在黄瓜霜霉病和黄瓜白粉病预测上的应用

为探索国内研制的新型一体化智能孢子捕捉系统在黄瓜霜霉病和黄瓜白粉病预测预报上的应用,在田间自然发病情况下,通过对捕捉孢子的形态进行识别,优化一体化智能孢子捕捉系统主要工作参数如有/无空气切割头、空气采集口高度和空气采集时间;通过病害及孢子的动态监测分析大棚黄瓜霜霉病和黄瓜白粉病病情指数与孢子捕捉量的关系。结果表明,当不加装空气切割头、空气采集口高度为70 cm、孢子捕捉时间在10:00—10:30时段有利于孢子的捕捉。黄瓜霜霉病和黄瓜白粉病病情指数与连续7 d孢子捕捉总量具有强正相关性。连续多日监测到黄瓜霜霉病菌孢子囊且数量快速增加是黄瓜霜霉病发生或快速上升的一个预测指标。黄瓜白粉病发病之前没有监测到黄瓜白粉病菌分生孢子,且在病害盛发期分生孢子捕捉量仍较少。研究表明,一体化智能孢子捕捉系统适用于黄瓜霜霉病的预测,但在黄瓜白粉病的预测上尚存在一定问题。     

2%武夷菌素水剂对草莓白粉病的毒力测定及田间防效

武夷菌素是一种农用抗生素类生物杀菌剂,温室及田间试验表明它对粮食、蔬菜、果树上的多种真菌病害有很好的防治效果,并且已经应用于农业生产中.为了考查其对草莓白粉病的防治效果,进行了室内孢子萌发抑制试验,结果表明武夷菌素能够抑制草莓白粉病菌孢子的萌发,其EC50为9.550 6μg/mL.同时田间药效试验结果表明,2％武夷菌素水剂对草莓白粉病具有良好的防治效果,其300倍液防治草莓白粉病的效果和化学农药10％苯醚甲环唑水分散粒剂相当,武夷菌素200倍液的防效显著高于化学农药,同时对草莓自身的生长发育没有影响.试验表明武夷菌素对草莓白粉病有很好的防治作用,可为生产上防治草莓白粉病和科学用药提供依据.     

番茄白粉病田间扩展流行规律与药剂防治试验

通过2年对番茄白粉病田间扩展流行动态调查和药剂防治试验研究,结果表明：番茄白粉病菌首先由中心病株下部叶片向上部作垂直扩散,随后进行水平传播,且顺垄传播快;在甘肃省张掖市一般7月中旬至下旬开始出现,田间蔓延快;环境条件适宜时,从植株上部叶片显症到发病率达91.5%仅需5 d。田间防治试验表明,喷药7 d后,24%噻呋酰胺悬浮剂1 200倍液、15%三唑酮可湿性粉剂750倍液、30%苯醚甲环唑&#8226;丙环唑乳油2 000倍液和62.25%代森锰锌&#8226;腈菌唑可湿性粉剂600倍液防效达到最大,依次为83.4%、81.4%、81.3%和68.7%,而喷药10 d后40%氟硅唑乳油3个浓度梯度（3 000、5 000倍液和7 000倍液）的药效均达到最高值,依次为72.2%、73.3%和78.5%,表明40%氟硅唑乳油持效期较长,药效稳定。