小豆疫霉茎腐病病原菌鉴定及抗病资源筛选

在黑龙江省佳木斯市合江地区农科所发现一种小豆疫霉茎腐病,典型症状是在茎部产生红棕色病斑,有时可在病茎和病荚产生白色霉层,严重时发病植株萎蔫、死亡.病原菌游动孢子囊卵圆形至倒梨形,无乳突,在孢囊柄上不脱落,平均大小为47μm×30μm,长宽比为1.6∶1.有性生殖为同宗配合,藏卵器圆形,平均直径为36.8μm,卵孢子平均直径为29.7μm,平均壁厚为2.9μm;雄器球形至卵圆形,围生,平均大小为16.4μm×15.7μm.生长温度为9～37℃,最适生长温度为24～27℃,生长抑制温度为39℃.完全抑制菌丝生长的孔雀绿浓度为5μg/ml,恶霉灵浓度为100μg/ml时对菌丝的生长相对抑制率为20%.病原菌无伤接种时只侵染小豆,伤口接种对绿豆、豇豆和菜豆具有不同程度的致病性.根据形态、生理、寄主范围和病害症状,病原菌被鉴定为豇豆疫霉菌小豆专化型(Phytophthora vignae f. sp. adzukcola).对70份小豆资源的抗性进行了室内接种评价,有7份资源表现抗病.     

冷季型草坪腐霉猝倒和叶腐病的发生规律及防治技术

研究了冷季型草坪腐霉猝倒和叶腐病发生规律和防治技术，结果表明，苗期处于20-30℃、持续高温、-必植（3-5株/cm^2）等条件下最有利于腐霉病菌的侵害；腐霉猝倒和叶腐病发生同草坪播种期关系密切，湿热季节（4月上旬至8月下旬）播种严重受害，雨后积水可导致毁坪，防治该病要改善草坪基因条件，在上年10月下旬至当年3月上旬播种，用25%甲霜灵WP100倍液浸种，适当稀播，发病季节多次喷施甲霜灵或乙磷铝等针对性农药。     

利用内吸杀菌剂—甲霜安和乙磷铝防治柑桔疫霉根腐病和脚腐病

柑桔树干由寄生疫霉菌(Phytophthoraparasttica Dast.)引起的疫病其防治主要在于预防,常用的方法是:于病害发生之初,清除被侵染的树皮,然后于该处施用杀菌剂。然而要大规模采用此法则费时费事也不经济。采用两种新的有希望的内吸杀菌剂来防治脚腐病和处理树干则不费劳力。一种为甲霜安(metalaxyl),对该药已进行了     

雪松疫霉根腐病菌

雪松疫霉根腐病菌(Phytophthora lateralis Tucker et Milbrath)是我国进境植物检疫性有害生物,可引起寄主植物严重的根腐病。鉴于该病原菌潜在的危险性,本文就其分布、寄主范围、传播方式、危害症状、形态特征以及检疫鉴定方法等进行了综述,供检疫鉴定参考。     

大豆疫霉根腐病菌毒素产生条件的研究

 大豆疫霉根腐病(Phytophthora sojae)是大豆的重要病害之一,危害大,发展快。自1918年首次在美国印弟安那州发现此病以来、相继在澳大利亚、加拿大,匈牙利等国发生。     

大豆疫霉和大豆疫病

大豆疫霉和大豆疫病彭金火谭红赵改萍（大连动植物检疫局大连１１６００１）（国家动植物检疫局北京）由疫霉引起的大豆（ＧｌｙｃｉｎｅｍａｘＬ．）根腐和茎腐病（大豆疫病）于１９４８年最先见于美国的印第安纳州,公开报道则在１９５５年。Ｋａｕｆｍａｎｎ＆Ｇｅｒｄ...     

木霉菌和腐霉菌对棉铃疫菌的作用研究

用玻璃纸对峙法观察到4种木霉(S-327,BT-12,BT-95,T-594)和寡雄腐霉(P.O.)对棉铃疫霉的营养生长均有一定抑制作用,但没有看到明显的抑菌圈。生物测定试验表明,拮抗菌不仅对棉铃疫霉有直接作用,而且还可以保护棉铃不受疫菌侵染。在5种拮抗菌中,P.O.和BT-12可能是防治棉铃疫病比较有潜力的生防菌。     

大豆疫霉根腐病菌游动孢子的产生因素

 本文对影响大豆疫霉根腐病菌游动孢子的产生因素进行了研究。8 d的菌丝体经蒸馏水浸泡,在25℃下培养72 h可以获得高浓度的游动孢子悬浮液,菌龄越短游动孢子浓度越大,偏酸性的环境有利于游动孢子产生,温度是影响游动孢子形成的重要因素,在0、35℃下均无游动孢子产生,游动孢子产生的适宜温度范围是20~30℃,最佳温度为25℃。     

玉米茎腐病病原菌检测方法研究

为提高玉米茎腐病病原菌检测结果的准确性和可信度,以组织分离法做对比,采用分子检测法,对采自田间的189个玉米茎腐病病株进行真菌种类的鉴定和数量的统计。结果表明,分子检测法对腐霉Pythiumspp.的检出频率为29.24%,对镰孢菌Fusariumspp.的检出频率为73.68%,组织分离法对腐霉的检出频率仅为0.58%,对镰孢菌的检出频率为60.82%,两方法的符合率最高仅为35.92%,最低为0。因此,采用组织分离和分子检测相结合的方法可提高玉米茎腐病病原菌鉴定结果的准确性。     

2009年甘肃省玉米穗腐病、茎基腐病的发生危害

2009年对甘肃省9个市的21个县、区玉米穗腐病、茎基腐病的发生危害情况进行了全面调查,并采集病害标样,进行病原分离。调查结果表明,玉米穗腐病、茎基腐病在全省各玉米种植区均普遍严重发生,病田率100%,病穗率和病株率平均为63.57%和34.47%。初步分离结果表明,全省玉米穗腐病、茎基腐病的主要致病菌为禾谷镰刀菌、黄色镰刀菌和轮枝镰孢菌,但在地区间的分布有明显差异。     

欧文氏杆菌引起梨果腐的一种新病害研究初报

近年来,在山东泰安发现梨果实软腐的新病害。从病部分离到一种细菌。根据个体形态,培养性状,生理化反应,致病性郑州 研究结果,确认致病菌为大黄颈腐欧文氏杆菌Ｅｒｗｉｎｉａｒｈａｐｏｎｔｉｃｉ（Ｍｉｌｌａｒｄ）Ｂｒｕｋｈｏｌｄｅｒ,非梨火疫菌Ｅ．ａｍｙｌｏｖｏｒａ。     

一种值得关注的花生新病害：花生新赤壳菌基腐病

2010年在我国广东省首次报道了由侵管新赤壳菌(Neocosmospora vasinfecta)侵染引起的花生新赤壳菌基腐病.罹病花生植株萎蔫、植株茎基部和根系变黑腐烂,在潮湿条件下,罹病部位有浅红色子囊果.这是我国大陆首次报道的花生新病害.该病害在广东省的多个市县有发生,严重的发病率高达30％.除广东省外,该病在我国江西省也有分布和危害,其致病菌可进一步鉴定为侵管新赤壳菌非洲变种(N.vasinfecta var.africana).在广东省也发现了由侵管新赤壳菌侵管变种(N.vasinfecta var.vasinfecta)引起的大豆茎枯病.对侵管新赤壳菌的文献进行了简要的综述.     

Increased content of phenolic compounds in pear leaves after infection by the pear rust pathogen

European pear rust induced by the fungus Gymnosporangium sabinae (Dicks) G. causes yellow to bright orange leaf spots on leaves of pear trees. The aim of this study is to identify and quantify polyphenolic compounds found in pear leaf extracts. Identified were: ten hydroxycinnamates, eight flavonols, nine flavan-3-ols and three arbutin derivatives. Polymeric procyanidins were additionally determined by UPLC-FL. The total content of phenolics in the control healthy green leaf extract was 11,889.98 mg but in the infected leaves it reached 28,573.89 mg in the samples with yellow spots and 11,480.06 mg/100 g dry matter (dm) in the green part of leaves. The yellow spots in pear rust leaves were characterized by increased content of flavanol (catechins and procyanidins) and arbutin compounds compared with the green part of the infected leaves and control healthy leaves.     

云南省珠芽魔芋(Amorphophallus bulbifer)软腐病病原菌鉴定

 魔芋 (Amorphophallus spp.) 是我国西南地区广泛种植的一种重要经济作物。2016~2018年在云南省发现一种由细菌侵染引起的珠芽魔芋新病害,症状表现为茎秆或叶片出现水渍状病斑,茎秆软化下垂,根部及球茎腐烂变褐,甚至整株倒伏。根据病害发病症状,并通过菌落形状、致病性测定、Biolog和16S rDNA测序分析,结果显示该病原菌在LB培养基上菌落呈近圆形,中央隆起,淡奶油色,质地均匀,表面光滑发亮;扫描和透射电子显微镜下观察显示,菌体形态呈短杆状,周生鞭毛,两端稍钝圆;基于16S rDNA扩增序列系统进化分析与已报道的Pectobacterium aroidearum strain CL1904-3 (MK875007) 相似性达99%以上,构建的系统进化树表明与P. aroidearum菌株亲缘关系最近,Biolog测定和16S rDNA序列分析均将该病原菌鉴定为软腐果胶杆菌 (P. aroidearum)。这是我国首次报道由P. aroidearum引起的珠芽魔芋软腐病害。研究结果进一步加深了人们对该病害的认识,为其防治提供了科学依据。     

我国甘薯新病害-茎腐病的研究初报

 2006年以来广东省主要甘薯产区发现1种甘薯新病害,主要症状表现为叶片变黄,茎基部呈黑色水浸状腐烂,并逐渐沿茎枝向顶端腐烂,后整株倒伏、死亡。从甘薯病茎部分离得到了病菌,经柯赫法则验证为致病病原菌。根据病原菌的形态特征、培养性状、生理生化及16S rDNA序列分析,鉴定其为菊欧文氏菌(Erwinia chrysanthemi)。采用茎枝、菌液共培养法接种8个甘薯品种,结果表明8个品种均无抗病性,病原菌致病性较强。这是我国首次发现该病害。      

云南省灯盏花根腐病病原物的分离及鉴定

报道了灯盏花(Erigeron breviscapus)主要栽培区发生的根腐病的危害情况及其症状,经过病原物的分离、致病性测定和形态鉴定,证明该病是由镰刀菌属(Fusarium)中的2种致病菌半裸镰孢(F. semitectum )和胶孢镰孢(F. subglutinans ) 侵染所致。     

西葫芦根腐和茎基腐病新病原-露湿拟漆斑菌Paramyrothecium roridum

 2013年12月,甘肃省白银市水川镇日光温室中的西葫芦发生了严重的根腐和茎基腐,部分棚室病株率达50%,从病根和病茎上分离得到拟漆斑菌属真菌3株,病株分出率27.3%。采用胚根和茎基部接种法测定了菌株FG-62对西葫芦的致病性:茎基部接种后27 d,植株开始出现凋萎;接种后40 d,两种接种法的西葫芦苗均呈现严重根腐和茎基腐症状,茎基部接种的西葫芦凋萎株率达30%;从病根和病茎上均可再分离出原接种菌。菌株FG-62在PDA平板上25℃培养14 d,产生大量墨绿色至黑色分生孢子座,分生孢子无色至淡榄黑色,单胞,杆状或腰鼓状,两端钝圆,大小为(7.04~9.15)μm ×(1.97~2.46)μm,聚集的分生孢子呈黑色。BLASTn分析结果显示,菌株FG-62(GenBank 登录号 MK252098)的rDNA-ITS序列与露湿拟漆斑菌Paramyrothecium roridum分离物E-469 (GenBank 登录号KY582183.1)和CBS 357.89(源自模式材料,GenBank 登录号NR_145077.1)的序列相似性分别达99.65%和96.83%。依据病原菌形态学和rDNA-ITS序列,将其鉴定为露湿拟漆斑菌P. roridum (Basionym:Myrothecium roridum)。这是露湿拟漆斑菌引起西葫芦根腐和茎基腐的首次报道。     

梨泡状溃疡类病毒的RT-PCR检测及序列分析

正梨泡状溃疡类病毒(Pear blister canker viroid,PBCVd)为马铃薯纺锤块茎类病毒科(Pospiviroidae)苹果锈果类病毒属(Apscaviroid)成员~([1])。该类病毒在自然条件下主要侵染野生和栽培的梨和苹果~([2~4]),梨和榅桲多数品种感染PBCVd后无明显症状,通过嫁接传染该类病毒可诱导梨指示植物     

Collar rot caused byPhytophthora citrophthora on pear trees in Greece

A severe crown rot of pear trees of cultivar ‘Kondoula’ grafted on quince rootstock was observed in Greece. Isolations from the affected tissues repeatadly yielded aPhytophthora sp. that was determined by morphological and physiological characteristics to beP. citrophthora. The pathogenicity of two of theP. citrophthora isolates was tested by inoculating trunks of 2-year-old pear trees by mycelial agar disks. Thirty-two days after inoculation all inoculated trees were infected. Although the pear isolates could not be differentiated from isolates ofP. palmivora orP. nicotianae based on isozyme profiles of α-esterase or lactate dehydrogenase, RAPD profiles with one selected primer differentiated the pear isolates from the other species and revealed an electrophoretic banding pattern similar to that of aP. citrophthora standard. This is the first report ofP. citrophthora on pear trees in Greece.     

A dynamic model forecasting infection of pear leaves by conidia of <Emphasis Type="Italic">Venturia nashicola</Emphasis> and its evaluation in unsprayed orchards

A dynamic model, called VenInf, was developed to forecast infection of pear leaves by conidia of Venturia nashicola. By simulating conidial infection processes following a rain event, the model estimates % conidia that successfully infected leaves at the end of an infection period. The model is mainly derived from logistic models developed from recent laboratory and glasshouse experimental results on infection of pear seedlings to estimate the rates of infection and mortality. It simulates the conidial infection process at 5 min intervals using temperature, relative humidity (RH), surface wetness and rainfall as input. The model was evaluated against pear scab in four unsprayed orchards in China over a 4-year period. In all orchards, all significant disease increases were associated with infection periods predicted by the model. In one orchard, in 2004 the incidence of leaf infection remained very low (<3%) during the entire season despite the model forecasting several severe infection periods. Results of orchard evaluation suggest that the model is able to identify all important potential infection periods. Thus, further field studies should be carried out to determine whether and how the model can be used in practice to assist farmers in making decisions on fungicide applications.