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1.
用烟草赤星病菌13个菌株分别测定了3种基本条件对病菌产孢能力的影响。当病原真菌在8个温度梯度下生长时,产孢指数—温度曲线近S型,产孢的最低、最适、最高温度范围分别为12~16°、24~28°、32~36℃。当病菌在17个pH梯度下生长时,产孢指数—pH梯度曲线也近S型变化,最低、最适、最高pH范围一般分别为pH3.5~4.0、6.5~7.5、9.5~10.0。在三种光照条件下测定表明,暗处理可以明显增强病菌的产孢能力。另外,菌丝体损伤对产孢能力不发生明显影响。  相似文献   

2.
对来自国内外不同地区不同寄主的24个松树枯梢病菌菌株的培养性状、离体生长速率、产孢特性、分生孢子表面纹饰及致病性等方面的变异进行了比较研究。结果表明:菌株问的培养性状存在显著变异,国内17个菌株可分为两类,第1类菌丝平铺,第2类菌丝为绒絮状气生。国外7个菌株除上述两类,尚存在其他类型。光照和营养是影响产孢的两大重要因素,各菌株在全黑暗的PDA培养基上培养50d以后均产生厚垣孢子。各菌株在灭菌湿地松松针上的产孢量有明显差异。分生孢子表面纹饰与菌株类型无关。各菌株对供试3种松苗的致病性存在明显差异,大多数菌株能无伤直接侵入一至多个松种。大多数菌株在培养性状、离体生长速率、产孢量、分生孢子表面纹饰与致病性等性状之间无明显相关性。  相似文献   

3.
不同胶孢炭疽菌菌株比较   总被引:2,自引:0,他引:2  
从我国6个省的38种植物上收集并鉴定43个胶孢炭疽菌(Colletorichum gloeosporiaides)菌株,比较和分析了它们的培养特征和生长适应性等性状。43个菌株的培养性状和不同培养条件(温度和pH)的生长适应性均存在着较大的差异。对43个菌株的分生孢子的长宽及43个菌株在不同条件下生长量进行单因素方差分析表明,菌株间的差异达到了极显水平。聚类分析把43个菌株分为距离相差不大的多个类群;各菌株的分.化与菌株的寄主种类和地理来源没有明显的相关性。因此菌昧的形态学特征不适合对林木胶孢炭疽菌进行种以下的类群划分。  相似文献   

4.
采用连续培养和连续接种的方法,研究了烟草赤星病菌致病力不同的6个菌株生长和产孢特性的变化。病菌在连续23代继代培养和连续11代继代接种过程中,菌落型、生长量和产孢量等培养性状基本保持稳定。  相似文献   

5.
研究了野生双孢蘑菇菌株 96 .4(Agaricusbisporus)和它的 2 0个单孢菌株的形态特征 ,生长发育 ,结实能力和杂交表现等方面 .研究表明 ,在菌株 96 .4和它的单孢菌株之间以及在 2 0个单孢菌株之间在子实体的形态和菌丝、孢子显微形态方面没有明显的差异 .但是在菌丝生长速度和子实体产量等方面都存在着明显的变异 .研究还表明在不同基因型的异核体菌株之间可能出现体细胞杂交 ,也许正是这种体细胞杂交的基因重组使得自然居群的遗传结构表现出明显的多态性 ,并保证了这一特殊物种的自然居群内的遗传多样性 .  相似文献   

6.
四川省玉米弯孢叶斑病菌的种类及生物学特性研究   总被引:4,自引:1,他引:3  
为了明确引致四川省玉米弯孢菌叶斑病(Maize Curvularia leaf spot)的病原菌种类和优势种,以便为病害的防治和抗病育种提供依据,对所获得的78个弯孢菌(Curvularia)菌株采用形态学分类法进行种类鉴定,结果鉴定出6个种或变种,其中属于新月弯孢菌(Curvularia lunata)种类的菌株占种群的61.5%,新月弯孢菌是四川省玉米弯孢菌叶斑病的主要致病菌种类.对属于其中3个种的4个弯孢菌菌株进行生物学特性研究,结果表明,各供试菌株在不同条件下的生长速度都存在一定的差异.  相似文献   

7.
小麦根腐平脐蠕孢病菌在PSA培养基上,极易发生菌落变异,变异后菌落呈半月形、扇形、放射形、不规则形。变异在培养中不稳定,可以恢复原菌落状态。变异后的菌落生长速度下降,菌体干重和产孢量降低,致病力明显低于不产生变异的菌株  相似文献   

8.
松墨天牛优良白僵菌菌株筛选   总被引:24,自引:2,他引:22  
从浙江省松墨天牛1松毛虫等不同寄主上采集了6个球孢白僵菌自然菌株,并从日本及国内主要生产厂家收集6个菌株,共计12个菌株。经过对其营养生长、产孢量、孢子活力、孢子耐热能力、孢子抗紫外线能力和室内对松墨天牛幼虫毒力等指标的研究,结果发现采自象山松墨天牛幼虫的菌株Bxs和来自日本松墨天牛的菌株F-263对松墨天牛幼虫的毒力最强,并且上述各指标均表现优良。尤其是Bxs菌株,其产孢量和抗紫外线能力大大高于  相似文献   

9.
芩贞陆  黄思良 《广西科学》2000,7(3):225-227,235
报道不同培养条件对Mang果炭疽病菌(Colletotrichum gloeosporioides)微循环产孢的影响。该病菌微循环产孢的pH值范围为4.0~10.0,最适为6.0;一定浓度的酵母膏液、葡萄糖液有利于其微循环产孢。黑暗、荧光与黑暗交替、荧光处理等促进微循环产孢,其中,以黑暗、荧光与黑暗交替处理产生的二次分生孢子的平均数最多,微循环产孢的适宜温度为20℃~35℃,最适为25℃~30℃;  相似文献   

10.
松枯梢病菌的培养性状和致病力变异及其相互关系   总被引:7,自引:3,他引:4  
对从我国13个省(市)16种松树和其它2种针叶树上收集的松枯梢病菌55个菌株在6种基质上进行性状培养的研究表明,我国松枯梢病菌在培养性状上存在明显的类群分化,模糊聚类分析将55个菌株2分为三个类群。采用人工接种方法测定供试菌株对5种实生苗的致病力。结果显示,该病菌的致病力在各菌株、不同松种或不同接种方法间均差异显。供试菌株的致病力分化状况与其在培养性状上所表现出的差异存在明显的相关性。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

13.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

14.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

15.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

16.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

17.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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