温度和植株叶面湿润时数对大豆灰斑病菌(Cercospora sojina)侵染的影响

 在人工气候箱内,控制接种温度(T)及植株叶面湿润时数(WD),研究了T及WD对大豆灰斑病菌(C.sojina)侵染的综合作用。温度、叶面湿润时数及其互作是病菌侵染的主要因素,病菌侵染温度范围为15~32℃,最适25~28℃,在适宜温度范围内,接种后保湿2小时病菌即可侵入。报导了大豆灰斑病菌侵染概率(IP)与T及WD的关系,组建了侵染概率预测模型。     

温度和植株叶面湿润时数对大豆灰斑病菌(Cercosp ora sojina)侵染的影响

在人工气候箱内,控制接种温度(T)及植株叶面湿润时数(WD),研究了T及WD对大豆灰斑病菌(C.sojina)侵染的综合作用。温度、叶面湿润时数及其互作是病菌侵染的主要因素,病菌侵染温度范围为15～32℃,最适25～28℃,在适宜温度范围内,接种后保湿2小时病菌即可侵入。报导了大豆灰斑病菌侵染概率(IP)与T及WD的关系,组建了侵染概率预测模型。     

苦瓜白粉病病原菌和生理小种的鉴定及苦瓜对白粉病的抗性遗传分析

为明确海南省苦瓜白粉病的病原菌、生理小种及苦瓜对白粉病的抗性遗传规律,结合形态学鉴定和分子鉴定解析白粉病菌及生理小种种类,通过显微镜观察白粉病菌侵染过程,并应用主基因+多基因混合遗传模型分析法探讨苦瓜对白粉病的主要抗性遗传规律。结果表明:采集自海南省6个市(县)的苦瓜白粉病病原菌均为单囊壳白粉菌Sphaerotheca fuliginea,属生理小种2F,该菌在侵染苦瓜叶片时有4个关键时期:接种后4 h为分生孢子萌发高峰期,8 h为附着孢形成高峰期,16～24 h为次生菌丝形成高峰期,5 d为分生孢子梗形成高峰期。将其接种于苦瓜抗、感品系,对白粉病的抗性符合2对加性-显性-上位性主基因+加性-显性多基因模型,主基因和多基因共同控制苦瓜对白粉病的抗性,其中以主基因遗传为主,且会受到环境变异的影响。根据苦瓜抗性遗传规律,F2代主基因遗传率最高,受环境影响最小,在苦瓜的白粉病抗性育种中,以早期世代F2代作为有效选择世代。研究表明白粉病菌侵染叶片的前2 d是白粉病防治的最佳时期,所以在白粉病易发的物候期,可将防治时间提前1～2 d。     

白粉病菌重寄生物——粉霉芽枝孢

寄生于枫杨白粉病菌上的重寄生物,经过调查研究,确定为芽枝孢(Cladosporium)的一个种。经与近似的重寄生芽枝孢比较,存在形态上和培养特性方面的区别,因此,确定应另立新种,称为粉霉芽枝孢(C.erysiphicola sp.nov.)。该菌不但能寄生于枫杨白粉病菌上,还能侵染枸杞白粉病菌及小麦白粉病菌等。对上述几种白粉病菌分生孢子的侵染,出现穿入孢子、缠绕菌丝、腐蚀孢子及使孢子萎缩等现象,有希望作为一种生物防治剂。该菌在培养基PSA及PDA上生长繁殖良好,其分生孢子除在不同营养液中萌发外,在蒸馏水中也能萌发。萌发的温度在27℃左右。     

小麦被白粉菌侵染所致结构、化学变化及其与抗病性的关系

 小麦白粉病菌(Eyrisphe garminis f.sp.tritici)过去一般年份主要在西南地区的云、贵、川等山区发生侵染和危害。     

蛇床子素对南瓜白粉病菌侵染的影响

采用室内离体叶片法,发现蛇床子素(osthol)处理能显著降低南瓜白粉病菌侵染的病情指数,接菌6 d后对照的病情指数为68.89,经100 μg/mL蛇床子素处理组的病情指数仅为15.56。显微观察发现蛇床子素可有效降低南瓜白粉病菌对寄主的入侵,并可有效抑制菌丝的生长。接菌后48 h,对照菌丝的平均长度接近400 μm,蛇床子素处理组菌丝平均长度仅有122 μm。苯胺蓝染色后显微观察发现蛇床子素还可降低白粉病菌的产孢量。     

番茄与白粉病菌互作反应中活性氧的积累

番茄白粉病菌Oidium neolycopersici是一种产生单生分生孢子的真菌,主要分布在欧洲、非洲、南北美洲和亚洲的一种世界性植物病害的病原菌~([1]).已有研究表明,受病原菌侵染的植物体内活性氧的积累与植物抗病性密切相关~([2]).目前关于番茄与番茄白粉病菌互作中活性氧进发与抗病性关系的研究,国内外很少报道.     

草莓品种对白粉病菌抗性的组织病理学研究

以4个生产上主栽草莓品种为试材,采用曲利苯兰透明染色法,系统研究了草莓白粉病菌在不同抗性草莓品种上侵染过程的组织学特征。结果表明,草莓白粉病菌的侵染过程可分为：分生孢子萌发、附着胞形成、侵入寄主产生吸器、菌丝扩展和分生孢子链产生。而草莓不同品种对白粉菌的抗性表现在附着胞产生后的各侵染阶段,随品种抗病性增强,病菌侵入率降低,吸器数目减少,菌丝扩展缓慢,分生孢子数目减少。     

湿度调控对番茄灰霉病菌侵染的影响

 番茄灰霉病菌(Botrytes cinerea)的分生孢子萌发需要高湿的环境,一般要求相对湿度在80%以上或水滴中萌发最好。在适温下,随着湿度的增加,病菌致病性增强,孢子在相对湿度85%以上、菌丝在相对湿度80%以上的高湿环境能够发生侵染,并形成危害性的软腐斑。在一天中高湿的时间直接影响番茄灰霉病的发生,高湿(相对湿度超过85%)时间8h以上病菌才能够连续侵染。     

橡胶树白粉菌Oidium heveae侵染寄主拟南芥的筛选

为筛选出橡胶树白粉菌Oidium heveae Steimnann新的寄主载体,通过接种野生型拟南芥Col-0、突变体Sr1-4D及eds1,观察了橡胶树白粉菌侵染不同拟南芥突变体的过程,PCR扩增测序法验证相关致病基因,构建橡胶树白粉菌-拟南芥互作体系。结果表明,在Col-0、Sr1-4D叶片上面,橡胶树白粉菌产生部分菌丝后停止生长,不能形成典型的橡胶树白粉病症状;但能成功侵染eds1叶片,在叶片的正、背面有银白色辐射状菌丝,后期在病斑上出现一层粉层,表现橡胶树白粉病的典型症状。组织染色和显微观察结果显示,在突变体eds1叶片上橡胶树白粉菌完成了侵染过程。PCR扩增测序结果表明接种后突变体eds1叶片上及组织中病菌均为橡胶树白粉菌;使用橡胶树白粉菌3个致病相关基因作为靶标,验证了eds1和橡胶树上白粉菌基因组中的3个致病相关基因相似度均达到99%~100%。表明橡胶树白粉菌可侵染拟南芥突变体eds1。     

小麦白粉病流行的IRM建模研究

 本文以温度和相对湿度为主要影响因素,根据IRM (Integrated Rate Methodology)的原理研制了小麦白粉病流行的动态模拟模型,同时对其参数进行了分析。模型模拟和预测结果表明该模型能较好地描述白粉病的流行。     

小麦白粉病菌有性阶段生物学特性研究初报

 小麦白粉病菌形成子囊孢子的必要条件之一是闭囊壳保持湿润。子囊孢子形成的温度范围为1~27℃,最适为11~15℃,紫外光、散光及黑暗无影响;酸碱度范围为pH3.2~9.2,以pH5.0~7.0最适。子囊孢子萌发的温度范围为1~36℃,最适为11~20℃;湿度范围为0~100%,以在水面及100%湿度时最高;黑暗及散光无影响;酸碱度范围为pH2.2~12.4,以pH5.0~8.0为最适。温度愈高、湿度愈大,病叶上的闭囊壳寿命则愈短。     

2002年部分麦区小麦白粉病菌对三唑酮的抗药性监测及苯氧菌酯敏感基线的建立

 采用拌种离体叶段法测定了2002年采自北京、江苏、山东、山西、河北、新疆和四川7省市部分麦区的109个小麦白粉病菌菌株对三唑酮和苯氧菌酯的敏感性,结果表明小麦白粉病菌群体对三唑酮敏感性EC₅₀平均值是63.70 μg/mL,平均抗性水平为30.48倍,最高抗性水平达142.97倍。其中江苏、山东、四川三地的菌株抗药性水平明显高于河北、北京、山西和新疆。同时测得病菌群体对苯氧菌酯的敏感基线EC₅₀值为85.82μg/mL,且白粉病菌对甲氧基丙烯酸酯类杀菌剂苯氧菌酯和三唑类杀菌剂三唑酮之间无交互抗性。该结果可为这两类杀菌剂在生产上的合理应用和抗药性治理提供依据。     

Effects of humidity on the development of grapevine powdery mildew

ABSTRACT The effects of humidity on powdery mildew development on grape seedlings and the germination of Uncinula necator conidia in vitro were examined. Studies were conducted at an optimum temperature of 25 +/- 2 degrees C. Disease on foliage was markedly affected by humidity levels in the test range of 39 to 98% relative humidity (RH), corresponding to vapor pressure deficits (VPD) of 1,914 to 61 Pa. Incidence and severity increased with increasing humidity to an optimum near 85% RH, and then appeared to plateau or decrease marginally at higher values. Conidial density and chain length also were proportional to humidity, but were influenced less strongly. There was a strong, positive linear relationship between humidity level and frequency of conidium germination with RH treatments of 相似文献   

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     

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。     

基于小麦白粉病菌rDNA ITS序列的PCR分子检测

 Wheat powdery mildew(Blumeria graminis f.sp.tritici) is the one of main wheat diseases in China.Based on the internal transcribed spacer(ITS) sequences of ribosome of B.graminis f.sp.tritici,three molecular primer pairs(F1/R,F2/R and F3/R) were designed to detect the fungal pathogen of wheat powdery mildew.The species specificity of these primers was confirmed.F1/R was demonstrated a higher sensitivity than the other two primer pairs,and could detect as low as 1 pg DNA of B.graminis f.sp.tritici.Furthermore,F1/R primer pair was used to detect the pathogen DNA extracted from wheat leaves showing chlorosis and typical symptoms of powdery mildew caused by artificial inoculation with B.graminis f.sp.tritici.The preliminary results demonstrated the usefulness of this primer pair and its potential applications in efficient detection of wheat powdery mildew pathogen from leaves with latent infections at early growth stages of wheat.     

The effects of constant and fluctuating temperatures on the length of the incubation period of apple powdery mildew (Podosphaera leucotricha)

The effects of constant and fluctuating temperatures on the incubation period of apple powdery mildew, caused by Podosphaera leucotricha , were studied. At constant temperatures, incubation periods ranged from 3 to 12 days over temperatures 8°C–30°C, and no visible lesions developed at 32°C. A nonlinear model was developed to describe the relationship between temperature and the rate of mildew colony development. The resulting curve is bell-shaped with an optimum temperature at about 23°C. When this model was used to predict mildew development under fluctuating temperatures at an integration step of 48 min, however, it consistently overestimated development rate for fluctuating periods with average temperatures higher than 20°C. A nonlinear model was also fitted directly to the fluctuating temperature data, thus taking into account the nonlinear effect. The overestimation of development rate by the constant model for high temperatures was confirmed when the two models were compared. This overestimation probably resulted from differences in the levels of relative humidity between constant and fluctuating temperature regimes. Possible practical use of the model is discussed.     

分子标记辅助选择小麦抗白粉病兼抗赤霉病聚合体

 Sumai 3, a wheat variety resistant to Fusarium head blight(FHB), was crossed with Neimai 9, a commercial wheat cultivar with the resistance to powdery mildew.The SCAR(sequence characterized amplified region) markers of powdery mildew resistance gene Pm21 and four SSR(simple sequence repeats)markers flanking the major FHB resistance QTL(Qfhs.ndsu-3BS) in Sumai 3 were used to detect the resistance loci by marker assisted selection(MAS) in the plants of the F₂ population.Identification of resistance to both powdery mildew and FHB in field showed that 12 plants resistant to both diseases were obtained.In addition, the agronomic traits of these plants were better than those of Sumai 3, and are perhaps the excellent parental materials for wheat breeding.     

陇南山区小麦白粉病流行程度预测模型

调查分析1990~2005年陇南山区小麦白粉病发生、流行资料,发现:陇南白龙江流域为小麦白粉病常发重发生区,徽成盆地为小麦白粉病易发区,西汉水流域为小麦白粉病轻发区;小麦感病品种面积、上年秋苗平均病叶率和病田率、当年早春平均病田率、上年7、10月和当年5月平均气温、当年4月和上年7、8、11月降水量与全市春季小麦白粉病流行程度相关十分显著,上年9月到次年3月平均气温和4~8月降水量与小麦白粉病流行程度呈正相关,4~8月平均气温和9月到次年3月降水量与小麦白粉病流行程度呈反相关。由此建立的预报模型,历史拟合率可达93.75%,2006年业务应用预报准确率100%。