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1.
为探寻具有杀螨潜力的生防真菌,采用喷雾法测定分析玫烟色虫草Cordyceps fumosorosea IF-1106菌株和球孢白僵菌Beauveria bassiana BB-1339菌株对朱砂叶螨Tetranychus cinnabarinus和二斑叶螨Tetranychus urticae卵、幼螨及雌成螨的致病力。结果表明,感染玫烟色虫草IF-1106菌株和球孢白僵菌BB-1339菌株后螨类的形态特征不一致,感染IF-1106菌株后形成棉絮状菌丝,而感染BB-1339菌株后则形成羊毛状菌丝。IF-1106菌株和BB-1339菌株对朱砂叶螨和二斑叶螨卵的LC50分别为2.38×107、8.26×107CFU/mL和4.48×107、1.21×108CFU/mL,对朱砂叶螨和二斑叶螨幼螨的LC50分别1.97×107、8.26×107CFU/mL和7.65×106、8.99×105...  相似文献   

2.
3.
Es konnten 132Bacillus-Stämme isoliert und gegenüber7 Rhizoctonia-solani- und 6Pythium-Stämmen auf Antagonismusin vitro untersucht werden. Die gefundenen Antagonisten hemmten die Pilzisolate unterschiedlich stark, so daß Gemische von Antagonisten für die Praxis zu empfehlen sind.There were 132Bacillus-strains isolated and tested for antagonism against 7 strains ofRhizoctonia solani and 6 strains ofPythium spp. The isolated antagonists didn't show a uniform effect against the tested strains ofRhizoctonia solani andPythium spp. For an application in practice it will be better to use a mixture of antagonists.
Mit 4 Abbildungen und einer Tabelle  相似文献   

4.
Es konntenBacillus-Isolate gefunden werden, die sich in Keimungsversuchen an Samen als antagonistisch gegenüberPythium aphanidermatum undRhizoctonia solani erwiesen. Die Versuche wurden mit Bohnen- und Gurkensamen durchgeführt. Die wirksamsten Antagonisten konnten in infizierter Erde Auflaufraten bei Gurken von 40–60% erzielen.Die Wirksamkeit der Antagonisten an Bohnen war niedriger, hier lagen die Keimraten kaum höher als 30%. Offenbar hängt die Wirksamkeit derBacillus-Antagonisten von der Fähigkeit ab Antibiotika zu produzieren und in Konkurrenz zu anderen Mikroorganismen zu treten.  相似文献   

5.
Floral malformation caused by Fusarium mangiferae is a serious threat to mango cultivation in various countries. Different long-term measures suggested to control it were found to be unsuccessful. Present studies clearly showed strong antifungal activity of a concoction brewed from Datura stramonium, Calotropis gigantea, Azadirachta indica (neem) and cow manure (T1) followed by methanol-water (70/30 v/v) extracts of Datura stramonium, Calotropis gigantea and Azadirachta indica (T2) against Fusarium mangiferae. Optimal control of floral malformation was found in trees sprayed with T1 followed by T2 at bud break stage and again at fruit set stage when compared with the control. All the malformed buds or panicles completely dried two days after foliar spray with T1 or T2. In the trees treated with T1 at fruit set stage, flower abscission was observed from the fourth day after spraying and all flowers dropped by the ninth day without requiring any manual de-blossoming, whereas in the control, the malformed panicles remained green and competed with the growing fruits for plant nutrients. In vitro culture of fresh malformed tissues in MS media along with T1 or T2 showed no growth of any fungus in the media. However, in vitro culture of the completely dry malformed tissues in MS media after foliar treatment with T1 or T2 revealed growth of F. mangiferae on the twenty fifth day indicating that the concoction-brewed compost (T1) or methanol-water (70/30 v/v) extracts (T2) could not completely eliminate the pathogen but helped in controlling malformation by suppressing the activity of F. mangiferae. Mango trees sprayed with T1 and T2 revealed significant differences in percent fruit set and retention when compared with the control. This could be due to observed higher levels of nitrogen, phosphorus, potassium, calcium, magnesium, copper, zinc, iron and manganese in T1, followed by T2 when compared with T3 (control). Among the different fruit quality parameters analysed, the total flavonoids were found to be significantly higher in T1 and T2 when compared with T3. The study proved that the concoction-brewed compost (T1) is effective, inexpensive, easy to prepare and constitutes a sustainable and eco-friendly approach to control floral malformation in mango when it is sprayed at bud break stage and again at fruit set stage. In this present study, exogenous treatment of emerging buds with (Tc) further proved that with increase in the number of malformed panicles/tree the number of buds developing into healthy panicles/tree decrease.  相似文献   

6.
欧亚种葡萄自交F1代对白粉病和霜霉病的抗性遗传   总被引:3,自引:0,他引:3  
采用田间自然鉴定、田间接种鉴定及室内离体叶圆片接种鉴定三种方法,研究了10个欧亚种葡萄品种(系)、一个欧山杂种及其493株自交后代幼苗对葡萄霜霉病及白粉病的抗性及遗传关系,同时对其自交后代抗白粉病和霜霉病的遗传趋势进行了分析.结果表明,供试品种(系)及其自交后代对霜霉病与白粉病的抗性存在极显著相关,自交后代对两病表现伴随遗传现象,初步推断这可能是由葡萄抗病基因的多效性引起.在欧亚种葡萄品种自交后代群体中,虽然90%以上都是感病性中等或高的类型,但仍能够得到一定比例(10%以下)抗病性强的类型,这为利用欧亚种葡萄品种进行自交或品种间杂交选育优质抗病新品种提供了依据.  相似文献   

7.
 自山东泰安及烟台地区的小麦全蚀病菌中提取到两种类型颗粒,一类是球形至多边形的病毒颗粒,直径在22~45毫微米之间,多数为27~32毫微米;另一类是棒状颗粒,长度为40~185毫微米×16毫微米,平均108×16毫微米,提取的球形病毒具有核蛋白的典型吸收光谱,最大和最小吸收值的波长分别在260毫微米和240毫微米,A260/240=1.24,A260/280=1.62。以烟台株病毒制备的抗血清,分别与烟台及泰安株病毒在琼脂免疫双扩散中作用均产生沉淀线,表明二者具有共同的血清型。烟台株病毒经苯酚抽提后的核酸样品最大吸收波长是260毫微米,最小是230毫微米,经聚丙烯酰胺-琼脂糖凝胶电泳分离为两条迁移率相近的带,表明此病毒有两个基因片断,在分类上属于需要两个dsRNA片断才能复制的等轴dsRNA真菌病毒。其外壳蛋白经测定含分子量70,000的多肽。<>br从浙江、湖北等11个省(市)的12株全蚀病菌中均提取到了病毒,比较了各菌的菌落颜色,生长速度和病毒浓度。  相似文献   

8.
The pathogenic fungi Verticillium alboatrum and Diplodia scrobiculata were assayed for biological control of Diplodia pinea on Aleppo pine (Pinus halepensis) in Catalonia (north-eastern Spain). Young shoots were pre-treated with inoculations of either V. dahliae or D. scrobiculata, by placing colonized agar plugs on wounds made by removing a single needle fascicle. An inoculation with D. pinea was performed 15 days later. Two months after the shoot inoculations, the canker length on the stems was measured and the percentage of shoot dieback calculated. Verticillium dahliae and D. scrobiculata were found to significantly reduce the canker length of D. pinea (P < 0.05) when compared with positive controls. Diplodia pinea was slightly more sensitive to V. dahliae than to D. scrobiculata, but no significant differences (P > 0.05) were observed in the mean canker length between the two treatments. Trees pre-inoculated with V. dahliae resulted in 31.12% shoot dieback, while those pre-inoculated with D. scrobiculata resulted in 32.18% shoot dieback, compared with positive controls (42.85%).  相似文献   

9.
 明确黄脉爵床棒孢霉叶斑病病原菌及其生物学特性,为防控提供理论依据。通过病原菌分离、形态特征观察、致病性测定、rDNA-ITS序列分析、生物学特性及寄主范围测定等研究,证明该病病原菌为山扁豆生棒孢Corynespora cassiicola;菌丝生长及产孢适宜温度20℃~28℃,孢子萌发适宜温度24℃~32℃,菌丝致死温度49℃处理10 min;菌丝生长适宜pH 6~10,产孢适宜pH 4~8,孢子萌发最适pH 8;光暗交替适合菌丝生长与产孢,连续光照可抑制菌丝生长;菌丝生长量由少到多培养基顺序为CA、PCA、PDA、CMA、OA,而PDA上产孢最多;刺伤接种,病菌可侵染喜树(Camptotheca acuminata)等植物。黄脉爵床棒孢霉叶斑病病原为山扁豆生棒孢C. cassiicola,病菌易产孢,寄主广,潜育期短。该病菌侵染黄脉爵床为首次报道。  相似文献   

10.
正甘薯茎枯病,又名甘薯蔓割病,主要由尖孢镰刀菌Fusarium oxysporum引起(Logeshwarn et al.,2011),近年来有向长江中下游蔓延的趋势。2015年,甘薯茎枯病在青岛市发病严重,发病率高达60%~70%,本课题组从青岛市即墨市采集的发病样本中得到了尖孢镰刀菌和极细链格孢Alternaria tenuissima两种病原菌。为探明这2种病原菌在致病性方面的关系,通过甘薯茎部接种致病性试验,明确青岛市甘薯茎枯病的致病菌种类以及不同致病菌间的复  相似文献   

11.
Restriction fragment length polymorphism (RFLP) analysis of the PCR amplified fragments of recA, gyrA and rpoS genes was applied for the characterization of Erwinia amylovora and Erwinia strains, which cause fire blight and Asian pear blight in orchards. Primers, constructed on the basis of the published recA, gyrA and rpoS gene sequences of Erwinia carotovora, allowed us to amplify DNA fragments for RFLP differentiation of E. amylovora and E. pyrifoliae and finally to distinguish strains within these species and relate them to pear pathogens from Japan. Three to seven restriction endonucleases were applied for RFLP analysis of each gene fragment. The electrophoretic patterns generated after PCR–RFLP for each of the tested genes, were characteristic and specific for each species and allowed their differentiation. The data show that PCR–RFLP analysis of the recA, gyrA and rpoS gene fragments may be considered as a useful tool for the identification and differentiation of E. amylovora and E. pyrifoliae. Almost identical restriction patterns of the analyzed gene fragments indicated a high relationship of E. pyrifoliae strains from Korea and pear pathogens from Japan and a divergence to E. amylovora. For quick and effective differentiation of E. amylovora strains from Erwinia strains from Asia without nucleotide sequencing we recommend the amplification of recA and rpoS gene fragments and digestion of each of them with restriction endonuclease Hin6I.  相似文献   

12.
为建立简单、快速和灵敏地检测瓜类细菌性果斑病菌Acidovorax avenae subsp. citrulli(Aac)和番茄细菌性溃疡病菌Clavibacter michiganensis subsp. michiganensis(Cmm)的环介导等温扩增(loop-mediated isothermal amplification,LAMP)方法,以Aac的ugpB基因和Cmm的micA基因为靶标,分别设计、合成和筛选特异性引物,摸索和优化各项反应条件和反应体系,成功建立了以钙黄绿素颜色为指示且只需要金属浴恒温反应30~60 min的LAMP扩增体系。特异性分析表明该LAMP方法可以快速检出5株不同的Aac菌株和2株不同的Cmm菌株,其它对照菌株如燕麦嗜酸菌燕麦亚种A. avenae subsp. avenae、丁香假单胞菌Pseudomonas syringae、水稻黄单胞菌水稻致病变种Xanthomonas oryzae pv. oryzae和茄科雷尔氏菌Ralstonia solanacearum则呈现阴性反应;引物比目前报道的LAMP引物有更高的DNA样品检测灵敏度,Aac和Cmm的灵敏度分别为1.72×10~2fg/μL和1.26×10~2fg/μL。研究结果表明,所设计的Aac和Cmm引物特异性好、灵敏度高,更有利于从源头上控制这2种检疫性细菌病害的流行和传播。  相似文献   

13.
Several species of fungi and oomycetes including Fusarium, Rhizoctonia, Phytophthora and Pythium have been reported as root pathogens of apple where they contribute to a phenomenon known as apple replant disease. In South Africa, little is known about specific species in these genera and their pathogenicity toward apple. Therefore, these aspects were investigated along with the development and optimization of qPCR tests for detection and quantification of the most virulent oomycete species. In eight investigated orchards, the oomycete Phythophthora cactorum was widely distributed, while nine Pythium species were differentially distributed among the orchards. Pythium irregulare was the most widely distributed and the most virulent species along with P. sylvaticum, P. vexans and Ph. cactorum. Seven binucleate Rhizoctonia anastomosis groups (AGs) were also differentially distributed among the orchards, with the majority appearing to be non-pathogenic while certain AG-I and AG-F isolates exhibited low virulence on apple. In the genus Fusarium, F. oxysporum was widely distributed, but isolates were non-pathogenic. Fusarium solani and F. avenaceum were less frequently encountered, with only some isolates having low virulence. qPCR data obtained from seedling roots inoculated with the most virulent Pythium species (P. irregulare, P. sylvaticum and P. vexans) and the genus Phytophthora were not always reproducible between trials, or isolates of the same species. In general, seedling growth inhibition was associated with the presence of a low amount of pathogen DNA (±40 fg μl−1 to 2 pg μl−1) in roots. Pythium irregulare, although having the lowest DNA concentrations in roots, was the only species for which a significant negative correlation was found between seedling weight and pathogen DNA concentration.  相似文献   

14.
为建立可同时快速检测引起向日葵黄萎病害的2种检疫性病原菌大丽轮枝菌Verticillium dahliae Kleb.和黑白轮枝菌V.albo-atrum Reinke et Berthold的方法,根据2种病原菌的β-tubulin基因分别设计特异性DPO引物,建立多重DPO-PCR检测方法,并对其特异性和灵敏度进行评价。结果表明,所设计的DPO引物特异性强,仅大丽轮枝菌和黑白轮枝菌可分别扩增出225 bp与151 bp的特异性条带,其它向日葵病害的7种病原菌及阴性对照均无目的条带;反应体系中引物终浓度为0.2μmol/L、退火温度为60℃时,30个扩增循环的检测灵敏度均可达0.05 ng菌丝DNA量;在45~65℃退火温度范围内均可高效扩增靶基因片段,表明该方法退火温度范围宽。所建立的检测方法能够准确、高效地检测引起向日葵黄萎病的大丽轮枝菌和黑白轮枝菌,可用于向日葵种子带菌筛查及田间病害诊断检测。  相似文献   

15.
为明确血蓝蛋白基因在新疆优势害虫西伯利亚蝗Gomphocerus sibiricus卵发育过程中的作用,本研究采用实时荧光定量PCR技术检测血蓝蛋白基因Hc1、Hc2在西伯利亚蝗卵不同发育阶段和1龄蝗蝻中的相对表达量,比较基因Hc1、Hc2相对表达量的差异,并分析这2个基因与土壤温度的相关性。结果表明,血蓝蛋白基因Hc1和Hc2在西伯利亚蝗卵所有发育阶段均有表达,并具有阶段特异性。在蝗卵早期发育阶段,Hc1基因相对表达量较高,Hc2基因相对表达量较低,其中在I阶段,Hc2基因相对表达量最低,为0.05;在滞育阶段,Hc1基因相对表达量降低,且在深度滞育期降至最低,为0.12,Hc2基因相对表达量略有增加;在滞育解除后发育阶段,Hc1基因相对表达量无显著变化,Hc2基因相对表达量在第VIII阶段最高,为17.26;在1龄蝗蝻阶段,Hc1基因相对表达量急剧升高至最大值,为39.43,Hc2基因相对表达量急剧下降。在西伯利亚蝗卵发育过程中,Hc1基因相对表达量平均数为8.83,高于Hc2基因的平均数,且蝗卵早期发育阶段、滞育后发育阶段和1龄蝗蝻阶段的Hc1和Hc2基因相对表达量之间差异显著。土壤温度与西伯利亚蝗卵各发育阶段和1龄蝗蝻阶段中Hc1基因相对表达量正相关,但相关性不显著,与Hc2基因相对表达量无显著相关性。  相似文献   

16.
Fusarium graminearum, Fusarium culmorum and Fusarium cerealis are major causal agents of Fusarium Head Blight (scab) which is a disease of global significance in all cereal growing areas. These fungi produce trichothecene mycotoxins, principally nivalenol (NIV) and deoxynivalenol (DON). Genes Tri13 and Tri7 from the trichothecene biosynthetic gene cluster convert DON to NIV (Tri13) and NIV to 4-acetyl-NIV (Tri7). We have developed positive–negative PCR assays based on these two genes, which accurately indicate a DON or NIV chemotype in F. graminearum, F. culmorum and F. cerealis. These assays are useful in assessing the risk of trichothecene contamination, and can be informative in epidemiological studies. All NIV chemotype isolates studied have functional copies of both Tri13 and Tri7, and all DON-producing isolates have both genes disrupted or deleted. We have identified several mutations in these genes, which are conserved across F. graminearum lineage, RAPD and SCAR groupings and between the three species. There appears to be evidence of inter-species hybridisation within the trichothecene biosynthetic gene cluster.  相似文献   

17.
为明确云南省元阳县籼/粳型稻瘟病菌中无毒基因的多样性及差异,采用接种鉴别品种方法和PCR技术对9株粳型菌株和21株籼型菌株中无毒基因Avr-Pia、Avr-Pita1和Avr-Pii的多样性进行分析。结果显示,30株稻瘟病菌菌株中无毒基因Avr-Pia、Avr-Pita1和Avr-Pii的平均出现频率分别为33.3%、76.7%和0,Avr-Pia、Avr-Pita1在籼型菌株和粳型菌株中的出现频率分别为4.8%和100.0%、66.7%和100.0%。Avr-Pia主要为存在/缺失的多样性,籼/粳型菌株对水稻品种Achiasahi(Pia)的致病率分别为100.0%和11.1%;Avr-Pita1可划分为3个类群,除菌株CH1195属于PO类群外,籼型菌株均属于J1类群,粳型菌株则属于J2/J3类群;籼/粳型菌株对水稻品种K1(Pita)的致病率分别为100.0%和0,且籼/粳型菌株Avr-Pita1蛋白序列在第83位和第192位氨基酸差异明显。Avr-Pii在30株稻瘟病菌菌株中均未检出,籼/粳型菌株对水稻品种Fujisaka No. 5(Pii)的致病率分别为100.0%和0。表明Avr-Pia和Avr-Pita1在粳型菌株中的出现频率高于籼型菌株且变异程度低,粳型菌株中可能存在其它无毒基因使其不能侵染Fujisaka No. 5。  相似文献   

18.
壳聚糖对水稻恶苗病菌和油菜菌核病菌的作用   总被引:6,自引:0,他引:6  
用平板含毒介质法测定了壳聚糖对水稻恶苗病菌(Fusarium moniliforme)和油菜菌核病菌(Sclerotinia sclerotiorum)的影响。结果表明,壳聚糖对F.moniliforme抑制作用相对较强,EC_(50)低于1000mg/L,而对S.sclerotiorum的作用较弱,EC_(50)高于3000mg/L。壳聚糖抑制F.moniliforme菌丝生长,导致菌丝畸形肿胀,产生不正常分支,并且抑制其分生孢子的萌发和芽管伸长。壳聚糖处理后F.moniliforme菌丝细胞膜的透性增加,导致蛋白质渗漏,但对其细胞膜的主要结构成分麦角甾醇的含量影响不明显。在离体培养时,壳聚糖对S.sclerotiorum产草酸毒素无明显影响,但预先经壳聚糖处理后,再接种S.sclerotiorum的油菜叶片中草酸含量显著减少。  相似文献   

19.
番茄枯萎病菌和青枯病菌拮抗细菌的评价   总被引:3,自引:1,他引:2  
为筛选出对番茄枯萎病和青枯病有较好防效的生防菌,采用平板对峙法,以番茄枯萎病菌Fusarium oxysporum和番茄青枯病菌Ralstonia solanacearum为靶标菌,从江苏沭阳、宿迁、溧水及内蒙古海拉尔分离到的2 062株细菌菌株中筛选拮抗菌株,并采用平板对峙法、拮抗菌液灌根法、分子生物学方法进行拮抗物质检测、盆栽试验及种属鉴定。结果表明:从2 062株细菌中共筛选到21株对番茄枯萎病和青枯病具有很强拮抗作用的菌株,均能分泌蛋白酶,具有解磷作用;不能分泌几丁质酶和纤维素酶,仅4株细菌能分泌嗜铁素。拮抗细菌SY290对番茄枯萎病和番茄青枯病防效最高,分别达到74.2%和75.0%,SQ728和LS536次之,但防效均大于60%。结合各菌株形态特征、16S r DNA与gyr-B序列分析结果,菌株SY177、SY290和SQ728鉴定为解淀粉芽胞杆菌Bacillus amyloliquefaciens,菌株LS536为枯草芽胞杆菌B.subtilis。  相似文献   

20.
玫烟色棒束孢与球孢白僵菌对桃蚜致病力对比   总被引:3,自引:2,他引:1  
为选取具有杀蚜潜力的虫生真菌,采用喷雾法比较研究了玫烟色棒束孢IF-1106和球孢白僵菌BB-1339对桃蚜成蚜的致病力,并利用时间-剂量-死亡率模型估计了2菌株对桃蚜的致死剂量与致死时间。结果表明,菌株IF-1106侵染桃蚜后菌丝如棉絮状,形成淡玫瑰色分生孢子,且菌丝侵染速度快于菌株BB-1339;菌株BB-1339侵染桃蚜后菌丝短而致密,形成白色分生孢子。菌株IF-1106在浓度为1×108 CFU/mL时,累计死亡率达到91.7%,而菌株BB-1339最高仅为55.0%。时间-剂量-死亡率模型中Hosmer-Lemeshow方法拟合异质性检验表明模型拟合良好,在接种后7 d,菌株IF-1106和BB-1339对桃蚜的半致死浓度分别为1.20×105 CFU/mL和8.15×107 CFU/mL;当浓度为1×108 CFU/mL时,2菌株对桃蚜的半致死时间分别为4.2 d和6.8 d。表明菌株IF-1106对桃蚜的致病力高于菌株BB-1339,更具开发潜力。  相似文献   

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