Periodicity and gradients in dispersal ofAlternaria linicola in linseed crops     

I. Vloutoglou  B. D. L. Fitt  J. A. Lucas 《European journal of plant pathology / European Foundation for Plant Pathology》1995,101(6):639-653

Conidia ofAlternaria linicola produced on infected linseed crops were mainly dispersed by wind. The numbers of conidia in the air above linseed crops collected by a Burkard spore sampler were greatest between 1200 h and 1300 h, when the relative humidity was lowest. Although numbers of conidia collected decreased with increasing height within and above the crop canopy, air-borneA. linicola conidia were present up to 80 cm above the crop canopy. Conidia ofA. linicola were transported by wind up to at least 40 m downwind from an artificial line inoculum source, but their numbers decreased with increasing distance from the source. In 1991, 1992, and 1993, the dispersal ofA. linicola conidia above linseed crops followed a seasonal periodicity which was influenced by weather conditions and cultural practices. The greatest numbers of conidia were collected during July, August and early September and coincided with periods favourable for sporulation and with an increase in the incidence of the disease in the senescent crop. Air-borneA. linicola conidia produced on point or line inoculum sources (naturally infected linseed stem debris) were responsible for the spread of the disease in linseed crops. In 1992 and 1993, the disease was first detected downwind from the sources, but by the end of the growing seasons, it had spread in all directions and up to 20 m and 60 m from the sources, respectively. Disease gradients were initially steep near the inoculum sources but they became flatter with time due to the secondary spread of the disease.  相似文献   

Detection of airborne inoculum of Leptosphaeria maculans and Pyrenopeziza brassicae in oilseed rape crops by polymerase chain reaction (PCR) assays   总被引：2，自引：0，他引：2  

C. Calderon ‡  E. Ward  J. Freeman  S. J. Foster  H. A. McCartney † 《Plant pathology》2002,51(3):303-310

The potential use of DNA-based methods for detecting airborne inoculum of Leptosphaeria maculans and Pyrenopeziza brassicae , both damaging pathogens of oilseed rape, was investigated. A method for purifying DNA from spores collected using Hirst-type spore samplers and detecting it using polymerase chain reaction (PCR) assays is described. For both pathogens, the sensitivities of the DNA assays were similar for spore-trap samples and pure spore suspensions. As few as 10 spores of L. maculans or P. brassicae could be detected by PCR and spores of both species could be detected against a background of spores of six other species. The method successfully detected spores of P. brassicae collected using spore traps in oilseed rape crops that were infected with P. brassicae. Leptosphaeria maculans spores were detected using spore traps on open ground close to L. maculans -infected oilseed rape stems. The potential use of PCR detection of airborne inoculum in forecasting the diseases caused by these pathogens is discussed.  相似文献   

暖地泥炭藓(Sphagnum junhuhnianum)孢子形态及发育过程探讨     

蒙文萍  冉景丞  何异杰  文洁斌 《种子》2017,(1):43-46

描述了暖地泥炭藓(Sphagnum junhuhnianum)孢蒴从翠绿色透明状球体历经黄绿色、淡褐色、褐色、具光泽的深咖啡色球体到最后喇叭状过程中孢子的形态特征.成熟孢蒴中孢子的数量(71 631±12 751)个.成熟孢子四面体结构清晰,极面观呈圆三角形,赤道面观呈近扇形,直径(23.27±1.05)μm,均出现三裂隙结构,唇状,稍细,长为极半径的2/3,裂隙表面布满疣状颗粒物,近极端三面凹陷无褶皱,分布少量疣状颗粒物,远端面不平整,布满疣状颗粒物.  相似文献   

贺兰山野生大型真菌孢子多样性分析     

卢玲  云兴福  吕世杰 《干旱区研究》2020,(2):479-486

为探讨贺兰山野生大型真菌孢子的多样性,2012-2016年在内蒙古贺兰山南寺和哈拉乌沟两地进行取样,每个样地分别由5人从沟谷入口处进行拉网式调查,共获得4 000余份样品,经过微观形态观察和基因ITS序列比对,鉴定出8目25科69属189种大型真菌,主要对其孢子形态特征、表面特征及长宽比进行分析,得到如下结论:质量性状上,孢子形态特征和表面特征相互独立;数量性状上,大小孢子长宽比、孢子极端比和平均比均具有一致性和关联性,显示孢子数量特征的稳定性;菌种间孢子质量性状和数量性状具有很强的多样性;按照孢子多样性低、中、高分类,贺兰山野生大型真菌物种数分别为152种、26种和11种;孢子多样性分类为大型真菌鉴别、分类提供了基本依据。  相似文献   

基于田间空气中病菌孢子浓度的小麦白粉病病情估计模型研究     

闫征远  范洁茹  刘伟  周益林 《植物病理学报》2017,47(2):253-261

2014和2015两年度利用Burkard定容式孢子捕捉器监测了高感小麦白粉病品种京双16种植区和中感品种众麦2号种植区田间空气中的病菌孢子浓度变化动态,同时利用小型气象站监测了田间的气象因子,通过分析京双16和众麦2号种植区空气中孢子浓度与空气温度、湿度、降雨、风速和太阳辐射率的相关性,发现空气中的孢子浓度主要与空气温度呈显著的正相关性(r0.348 3,P0.05)。在此基础上,分别分析了田间病情与调查日期前累积孢子浓度、一周前累积孢子浓度、前一周累积孢子浓度和当周累积孢子浓度的关系,结果表明,中感品种众麦2号田间病情与累积孢子浓度的关系均呈指数关系,其中田间病情与调查日期前累积孢子浓度或一周前累积孢子浓度的拟合效果最好,而感病品种京双16的田间病情与累积孢子浓度多呈对数关系,其中病情指数与一周前累积孢子浓度的拟合效果最好。  相似文献   

稻瘟病菌菌株在寄主上的相互作用研究   总被引：2，自引：0，他引：2  

何月秋  曾小萍  文艳华  黄瑞荣 《植物保护学报》1991,18(3):247-252

作者采用常规的组织分离、单孢分离、孢子培养和接种的方法,研究了稻瘟病菌菌株在14个品种秧苗上的相互作用。结果表明,所有不同来源的单孢菌株间、集团菌株间在中等抗性品种上均有各种类型相互作用。从简化鉴定工作程序和接近病菌在大田存在互作的实际出发,作者建议以不同地区和不同品种的集团菌株混合接种,测定育种早稻材料的抗病性。  相似文献   

环境因素对芸苔链格孢生长发育的影响   总被引：2，自引：0，他引：2  

李明远  柯常取  曾丽 《植物保护学报》1991,18(4):317-322

研究结果表明,芸苔链格孢(Alternaria brassicae)在0—35℃下均可萌发,最适温度15—20℃。菌丝在0—30℃下均能生长,最适温度20—25℃;孢子及菌丝的致死温度为50℃,10分钟。该菌对湿度要求较严格,相对湿度在90％以上时孢子才能萌发,最适相对湿度为98％;病菌在相对湿度达93％时可以侵染,98％以上最适。脱落后孢子曝露在室内(相对湿度约63％)经1小时萌发率下降32.4％,4小时下降80％。耐旱能力较差。一般情况下紫外光能促进该菌产孢,但是对某些菌系的促进作用不明显。过长的紫外光照射对该菌产孢不利,照射160分钟孢子萌发率下降近80％。麦芽糖、蔗糖为该菌的最佳碳源;硝态氮、有机氮是该菌的良好氮源。pH值为4—6时有利于分生孢子萌发,强酸、强碱对分生孢子萌发有抑制作用。  相似文献   

Modelling the escape of Chondrostereum purpureum spores from a larch forest with biological control of Prunus serotina     

Meindert D. De Jong  Patricia S. Wagenmakers  J. Goudriaan 《European journal of plant pathology / European Foundation for Plant Pathology》1991,97(1):55-61

Chondrostereum purpureum is being developed as a microbial herbicide to controlPrunus serotina in coniferous forests. After biological control, the fungus produces basidiospores that may reach and infect non-target plants. As part of a risk analysis, spore escape from a forest was quantified. For this purpose, a stratified model was developed for a forest of 250 m with 250 m. A turbulent diffusion equation was used to describe spore fluxes for each layer.In a simple calculation procedure, the spore fluxes for the different layers were calculated simultaneously. The downwind escape fraction was found to vary from 0.19 to 0.45, and the upward escapte fraction from 0.07 to 0.23. These escape fractions increased with increasing wind speed.Number of spores released from basidiocarps, and escape fractions could be used as inputs for a Gaussian plume model to calculate spore immission into orchards.  相似文献   

PCR-based detection of sterol demethylation inhibitor-resistant strains of Penicillium digitatum     

Hamamoto H  Hasegawa K  Nakaune R  Lee YJ  Akutsu K  Hibi T 《Pest management science》2001,57(9):839-843

  相似文献   

小麦白粉病纯化菌种保存方法   总被引：4，自引：2，他引：4       下载免费PDF全文

曹远银  于基成  刘秋  魏松红 《植物保护学报》2005,32(3):271-274

利用经初选确定的5种具有较好保鲜能力的配方,采用离体叶段滤纸保存法、离体叶段琼脂保存法和试管苗保存法对小麦白粉病菌纯化菌系保存效果进行了研究.结果表明,对小麦幼苗第一叶叶段保鲜效果最好的配方是沈保6号,当使用40～60μg/mL最适浓度时,第25天叶段绿色仍可达到90%以上.保存菌种的最适环境条件研究结果表明,在4℃冰箱中,以离体叶片沈保6号琼脂保存和离体叶沈保6号浸润滤纸保存效果最佳,在第40天叶片绿色仍分别达到78.0%和68.0%,孢子萌发率可达26.7%和26.8%.  相似文献