吉林省香菜一新病害——白粉病

通过病害症状和病原形态学特征对吉林省香菜种植区白粉病病原菌进行鉴定,结果为该病由独活白粉菌（Erysiphe heraclei DC．）引起。香菜白粉病为吉林省香菜一新病害,且芫荽属为东北地区白粉菌属级新记录寄主。     

瓜类白粉病的生物防治研究进展

白粉病是危害瓜类作物最为严重的一种气传病害,引起该病的病原菌为单囊壳白粉菌Podosphaera xanthii(synonym Podosphaera fusca)和二孢白粉菌Golovinomyces cichoracearum(synonym Erysiphe cichoracearum),其中对Podosphaera xanthii的报道较为常见。主要概述了瓜类白粉病病原菌的分类地位、病理特征和生物防治方面的研究进展,重点阐述了微生物源生防制剂和植物源生防制剂对瓜类白粉病的防治成果,并对当前研究与应用中存在的问题进行了探讨,为该病的深入研究和有效防治提供参考。     

辽宁铁岭榛白粉病病原菌研究

榛是辽宁铁岭市最重要的木本经济树种。白粉病是榛生产中的主要病害,导致树体衰弱,减少花芽分化,落果,降低产量。本研究对该病害的发生和危害进行了调查,通过病原菌形态学和rDNA ITS序列分析,确定该病害的病原菌为榛白粉菌(Erysiphe corylacearum)。     

吉林省枸杞白粉病病原菌鉴定

对枸杞白粉病病原菌形态进行详细观察,发现了引起枸杞白粉病的病原菌—穆氏节丝壳Arthrocladiella mougeotii。节丝壳属为吉林省新记录属,枸杞白粉病为吉林省新病害。另外还发现了枸杞上同时寄生有反卷白粉菌Erysiphe kenjiana,通过对采集环境、病菌分生孢子形态观察和萌发试验的研究分析,确定这种寄生现象为"假寄生"。     

紫花苜蓿白粉病病原菌鉴定及其生物学特性

【背景】白粉病是影响苜蓿产量和品质的主要真菌病害之一,引起紫花苜蓿白粉病的病原有3种:蓼白粉菌(Erysiphe polygoni DC.)、豆科内丝白粉菌(Leveillula leguminosarum Golov.)和豌豆白粉菌(Erysiphe pisi DC.)。【目的】系统研究紫花苜蓿白粉病病原菌的生物学特性,以及分生孢子和闭囊壳的形态特征,明确宁夏地区紫花苜蓿白粉病病原种类。【方法】采用室内盆栽法调查病害发生和闭囊壳形成条件,利用气象站自动获取数据,采用光学显微镜观察病原菌特征,采用水琼脂玻片法观察病原菌分生孢子萌发特性。【结果】紫花苜蓿白粉病发生的温度范围为20-24℃,湿度范围为40%-60%,形成闭囊壳的条件为温度20-25℃、湿度70%左右,闭囊壳的形成大约需要42 d。分生孢子以向基式的产孢方式在分生孢子梗上产孢,成熟的分生孢子卵圆形或椭圆形,大小为(29-46)×(12.5-21.0)μm。闭囊壳黑褐色,球形或近球形,直径71-135μm,具有大量附属丝,少数为不规则分枝1-2次。闭囊壳内含有4-6个子囊,子囊倒棒型或卵圆形,具柄,大小为(58-90)×(29...     

中国白粉菌目分类学研究现状

白粉菌是一类植物专性寄生病原菌,在世界各地可引起多种植物白粉病。近年来,形态学与分子系统学和超微结构分析相结合明确了白粉菌的系统发育地位和亲缘关系,使白粉菌的分类系统发生了很大变化。目前白粉菌科主要分为5个族,包含16个有性型属和2个无性型属。中国的22个省、5个自治区和2个直辖市报道有白粉病发生,共计13个有性型属328种及44变种,其中白粉菌族种数最多,其次是球针壳族。中国真菌学家命名的白粉菌新属4个、新种143个,其中仅在中国报道的有105个。寄主植物多达90科339属799种和变种,其中豆科上报道的种数最多,其次是蔷薇科。分子系统学的研究表明ITS、28S r DNA、MAT1-2-1、β-tubulin、IGS、CSⅠ和EF-1α等DNA片段可用于辅助白粉菌的鉴定,并为白粉菌分类系统的建立提供佐证。     

香薷白粉病菌及其重寄生菌的分离鉴定

对采自中国长春香薷白粉病菌进行系统观察和测量,鉴定其为本间白粉菌(Erysiphe hommae Braun),同时发现了重寄生菌——白粉寄生孢（Ampelomyces quisqualis Ces.）,并对重寄生茵的叶部寄生特征及培养特征进行了描述.室内检测结果表明,重寄生菌的重寄生强度较高,可抑制白粉病的发生.     

广西高峰林场相思树的真菌病害调查

相思树是从澳大利亚引进的速生丰产林种,在广西以高峰林场为主要种植基地。经初步调查,不同相思树上发生的真菌性病害不同,马占相思树、厚荚相思树、直干相思树、纹英相思树、杂交相思发生炭疽病,其病原茵为胶孢炭疽菌(Colletotrichum gloeosporioides),在马占相思、直干相思、纹荚相思和杂交相思的叶片上只产生病原菌的无性阶段,而在厚荚相思叶片上可同时出现无性阶段和有性阶段;马占相思树和杂交相思树上发生的白粉病菌为白粉菌Oidium sp．,其中杂交相思白粉病发生普遍而严重,发病期多在3-5月;黑木相思树发生叶尖枯病,病原为异色拟盘多毛孢(Pestalotiopsis versicolor),一年四季均可发病;马占相思树干基部心腐病发生严重,造成木材的大量损失,病原尚未得到确定。本文对病害的症状特点、病原菌形态特征进行了描述。     

南瓜白粉病病原菌鉴定及寄主范围测定

通过对南瓜白粉病病原菌的闭囊壳、分生孢子及萌发方式的观察和鉴别寄主感病反应鉴定,结果表明引起甘肃省武威地区南瓜白粉病的病原菌为苍耳单囊白粉菌Podosphaera xanthii。该白粉病菌闭囊壳形成的最适条件为温度20℃、相对湿度70%和光照强度4,400lx。寄主范围测定结果表明,该病菌不侵染丝瓜、小麦、辣椒、番茄、苜蓿、红三叶草、架豆和菜豆,可侵染除丝瓜之外的其余9种瓜类植物和绿豆、红小豆、向日葵,其中对南瓜、绿豆、西葫芦、红小豆、向日葵、甜瓜和黄瓜的致病性最强,发病率均达到100%,病情指数分别为15.56、14.51、13.33、13.33、13.07、12.22和12.22。侵染过程观察发现,感病南瓜人工接种白粉菌12h后,分生孢子芽管从侧面萌发,于24h芽管伸长,于36h形成菌丝,于72h形成稠密的网状菌丝,于96h形成分生孢子梗及串生分生孢子。     

大麦抗白粉病基因Mlo的研究进展

野生型Mlo基因是大麦抗白粉病的负调控因子,该基因突变,赋予大麦对白粉菌的广谱抗性。综述了Mlo基因结构、功能及Mlo突变的等位基因(mlo)的抗性特点;讨论了mlo基因可能的抗病机制。为mlo抗性在麦类白粉病抗病育种中的应用提供了理论基础。     

Mutual interplay between phytopathogenic powdery mildew fungi and other microorganisms

Powdery mildew is a common and widespread plant disease of considerable agronomic relevance. It is caused by obligate biotrophic fungal pathogens which, in most cases, epiphytically colonize aboveground plant tissues. The disease has been typically studied as a binary interaction of the fungal pathogen with its plant hosts, neglecting, for the most part, the mutual interplay with the wealth of other microorganisms residing in the phyllo- and/or rhizosphere and roots. However, the establishment of powdery mildew disease can be impacted by the presence/absence of host-associated microbiota (epi- and endophytes) and, conversely, plant colonization by powdery mildew fungi might disturb indigenous microbial community structures. In addition, other (foliar) phytopathogens could interact with powdery mildews, and mycoparasites may affect the outcome of plant–powdery mildew interactions. In this review, we discuss the current knowledge regarding the intricate and multifaceted interplay of powdery mildew fungi, host plants and other microorganisms, and outline current gaps in our knowledge, thereby setting the basis for potential future research directions.     

伞房决明白粉病的初次报道(英文)

伞房决明是长江三角洲地区的园林绿化木本植物,在每年8月下旬至11月中旬会发生严重的白粉病,造成提前落叶,导致次年部分植株死亡。该病由Oidium cassiae-siameae引起。经过3年多的野外观察,未发现有性世代。初次报道伞房决明为Oidium cassiae-siameae白粉菌的新寄主。此真菌为中国大陆的初次记载。     

Ecological basis of the interaction between Pseudozyma flocculosa and powdery mildew fungi

In this work, we sought to understand how glycolipid production and the availability of nutrients could explain the ecology of Pseudozyma flocculosa and its biocontrol activity. For this purpose, we compared the development of P. flocculosa to that of a close relative, the plant pathogen Ustilago maydis, under different environmental conditions. This approach was further supported by measuring the expression of cyp1, a pivotal gene in the synthesis of unique antifungal cellobiose lipids of both fungi. On healthy cucumber and tomato plants, the expression of cyp1 remained unchanged over time in P. flocculosa and was undetected in U. maydis. At the same time, green fluorescent protein (GFP) strains of both fungi showed only limited green fluorescence on control leaves. On powdery mildew-infected cucumber leaves, P. flocculosa induced a complete collapse of the pathogen colonies, but glycolipid production, as studied by cyp1 expression, was still comparable to that of controls. In complete contrast, cyp1 was upregulated nine times when P. flocculosa was applied to Botrytis cinerea-infected leaves, but the biocontrol fungus did not develop very well on the pathogen. Analysis of the possible nutrients that could stimulate the growth of P. flocculosa on powdery mildew structures revealed that the complex Zn/Mn played a key role in the interaction. Other related fungi such as U. maydis do not appear to have the same nutritional requirements and hence lack the ability to colonize powdery mildews. Whether production of antifungal glycolipids contributes to the release of nutrients from powdery mildew colonies is unclear, but the specificity of the biocontrol activity of P. flocculosa toward Erysiphales does appear to be more complex than simple antibiosis.     

普通小麦99-2439 中的白粉病抗性遗传

普通冬小麦品系99-2439在郑州连续4年对田间白粉菌(Blumeria graminis sp. tritici)表现高抗,但其抗性基因来源不清。通过染色体C-分带和1RS染色体特异性SCAR标记鉴定, 表明它是一个小麦-黑麦(Triticum aestivum - Secale cereale)1BL/1RS异易位系。通过对中国春×99-2439杂交F2代分离群 体抗性鉴定和1RS染色体臂检测结果分析, 证明该抗病基因不在1RS染色体臂上。用单孢小麦白粉菌分离株对其抗性遗传进行研究, 结果表明, 99-2439的白粉病抗性由一对小种专化、隐性抗病基因控制。由于携带Pm5a的Hope/8Cc对中国的21个小麦白粉菌分离菌株均高度感病, 而99-2439高抗混和白粉菌和5个单孢分离菌株, 所以, 99-2439所携带的抗白粉病基因不同于Pm5a。     

Paecilomyces fumosoroseus (Deuteromycotina: Hyphomycetes) as a potential mycoparasite on Sphaerotheca fuliginea (Ascomycotina: Erysiphales)

Hyphomycete Paecilomyces fumosoroseus that is well known as saprophytic and entomopatogenic fungus was investigated for its mycoparasitism on the cucumber powdery mildew pathogen. Mycoparasitism was documented by using standard bioassay and SEM. Effects of mycoparasitism were evaluated in three types of experiments. Paecilomyces fumosoroseus was applied in the form of graded suspensions into a colony of powdery mildew on a leaf segment. Interaction between both fungi was observed as the percentage of colonized area vs. experimental time. In the second experiment, young cucumber plants were sprayed with a suspension of Paecilomyces fumosoroseus 24 h before inoculation of Sphaerotheca fuliginea. Pre-treatment with P. fumosoroseus reduced development and spreading of powdery mildew infection significantly 15 days post-inoculation in contrast to pre-treatments with sulfur fungicide and distilled water. The development of pure culture powdery mildew under determined experimental conditions was observed and compared with treated variants. In the third experiment, mildewed plants were treated with a suspension of P. fumosoroseus. The control treatments with sulfur fungicide and distilled water were tested. Effects of P. fumosoroseus on the dispersion of powdery mildew during a 21-day period were observed.P. fumosoroseus suppressed the development and spread of cucumber powdery mildew significantly during the time of the experiment. The mechanical and physical damages and disruptions of vegetative and fruiting structures of powdery mildew were recorded under light microscopy and S.E.M.Results were concluded in pursuance to differences between the natural behaviour and development of S. fuliginea on cucumber plants treated with P. fumosoroseus and non-treated plants.     

Effects of Sunflower Oil on Tomato Powdery Mildew Caused by Oidium neolycopersici

When tomato leaves were sprayed with 0.1% emulsified canola oil, corn oil, grape seed oil, peanut oil, safflower oil, soya bean oil or sunflower oil, the severity of powdery mildew caused by Oidium neolycopersici was greatly reduced. Among these edible oils tested, sunflower oil was the most effective in the control of powdery mildew. When sprayed with 0.5% sunflower oil, powdery mildew on tomato leaves was reduced to a negligible level. Sunflower oil applied to halves of upper leaf surface did not induce resistance against the pathogen in the non‐treated halves. When applied to halves of lower leaf surface, it also failed to reduce the severity of powdery mildew on the upper leaf surface right above the treated area indicating that control of the powdery mildew by sunflower oil did not result from activation of host defence mechanisms. Scanning electron microscopy showed that control of powdery mildew with sunflower oil resulted mainly from the inhibition of conidial germination and suppression of mycelial growth of the pathogen.     

Differentiation of Two Pathogens of Powdery Mildew Disease in Flowering Dogwood (Cornus florida) by PCR-mediated Method Based on ITS Sequences

Two fungi, Phyllactinia guttata and Erysiphe pulchra were identified as the pathogens of powdery mildew of flowering dogwood ( Cornus florida ). The objective of this research was to identify and distinguish the two fungi by developing species-specific primers. The internal transcribed spacer (ITS) universal primers and a series of species-specific primers designed from the ITS regions were used to evaluate and validate the two fungi causing powdery mildew in dogwood. Four primer pairs showed specificity to P. guttata and three to E. pulchra . These species-specific primer pairs can be used as molecular markers to provide diagnostic tools for detection and differentiation of the two powdery mildew pathogens in flowering dogwood.     

Endogenous Abscisic Acid in Wheat Plants upon Inoculation with the Powdery Mildew Causative Agent (Erysiphe graminisf. sp. tritici)

We studied the dynamics of the abscisic acid content in above-ground parts of wheat cultivars with different resistance against powdery mildew. It was assayed by the HPLC method in healthy and diseased (inoculated by the powdery mildew causative agent) plants (from inoculation to the stage of pathogen spore formation). The results are discussed with special reference to the wheat resistance against the powdery mildew.