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山东省大豆根腐病病原菌及其生物学研究 总被引：10，自引：2，他引：10
1988-1989年采集山东大豆根腐病标样553个,经分离接种证明,致病菌有茄病镰刀菌[Fusarium solani(Mart.)Sacc.]、尖孢镰刀菌(F.oxysporum Schl.)和木贼镰刀菌[F.equiseti(Corda)Sacc.]三种,以茄病镰刀菌的分离频率最高,致病力最强,为主要致病菌。并对其培养特性、形态特征、寄主范围和光照、温度及pH对生长的影响进行了研究,根据这些研究结果,将大豆根腐病主要致病菌定名为茄病镰刀菌大豆专化型[Fusarium solani(Mart.)Sacc.f.sp.glycines Li et Luo],本专化型过去没有报告。 相似文献
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离体玉米根冠细胞对Hm—毒素敏感性的研究 总被引：2，自引：0，他引：2
在试验的两种Hm-毒素生物测定法中,根冠细胞测定法的效果比种子根伸长法好,主要是前者对Hm-毒素的敏感性强,与病斑大小有极显著的相关性。抑制种子根伸长法由于不能确切反映玉米对小斑病的反应,因而不宜用作Hm-毒素的生物测定。在不同的毒素制剂中,以病叶提取液处理根冠细胞最能反映小斑菌接种玉米后的实际情况,与病斑大小的相关系数r=0.9315,居供试的三种制剂之首,其次是粗提制剂和培养物滤液。试验还发现酒石酸铵不仅影响Hm-毒素测定的效果,而且还影响毒素产生的量,因而进行Hm-毒素的生物测定,最好使用病叶提取液或用无酒石酸铵的改良Fries培养基制备的毒素粗提制剂或培养物滤液。 相似文献
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35个马铃薯品种对镰刀菌干腐病优势病原的抗病性评价 总被引：3，自引：2，他引：1
为合理利用抗源,用菌株混合接种法分别接种接骨木镰刀菌Fusarium sambucinum和茄病镰刀菌F.solani,以DPS2000数据处理系统对接种块茎第15天腐烂斑的半径进行系统聚类分析,从而探讨35个马铃薯品种对镰刀菌干腐病优势病原的抗病性。结果表明:以接种接骨木镰刀菌的块茎其腐烂半径原始数值不转换、接种茄病镰刀菌的块茎其腐烂半径原始数值进行标准化转换、聚类方法均采用欧式距离、最长距离法,其聚类效果与接种结果的吻合度最好。接种接骨木镰刀菌后,以欧式距离21作为最佳聚类距离分割点,将试验品种分为11个抗病品种、17个中抗品种和7个感病品种;接种茄病镰刀菌后,以欧式距离3.0作为最佳聚类距离分割点,将试验品种分为13个抗病品种、14个中抗品种和8个感病品种。 相似文献
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云南灯盏花根腐病的2种新病原鉴定及防治药剂的室内筛选 总被引：1，自引：0，他引：1
引起云南省灯盏花根腐病的病原为茄病镰刀菌(Fusarium solani)、尖孢镰刀菌(F.oxysporum)和半裸镰刀菌(F.semitectum)3种真菌,茄病镰刀菌和尖孢镰刀菌为灯盏花根腐病的2种新病原,其中茄病镰刀菌为主要致病菌,其分离率为42.86%,茄病镰刀菌有伤接种发病率为70%,无伤接种发病率为56.7%。采用室内生长速率法测定了50%多菌灵可湿性粉剂、70%甲基硫菌灵可湿性粉剂、64%恶霜·锰锌可湿性粉剂、10%苯醚甲环唑水分散粒剂、10亿活芽胞/g 枯草芽胞杆菌·荧光假单胞杆菌可湿性粉剂5种供试杀菌剂对灯盏花根腐病主要病原茄病镰刀菌的毒力。结果表明：5种供试药剂对茄病镰刀菌都有抑制作用。对茄病镰刀菌的有效中浓度（EC50）分别为0.000 4、0.050 7、0.053 5、0.081 3和8.624 0 mg/mL,其中50%多菌灵可湿性粉剂有效中浓度最低,相对抑制效果最好。5种药剂的毒力相关系数均在0.89以上,表明药剂质量浓度与抑制作用呈较高相关性。 相似文献
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玉米青枯病病原腐霉对其伴生镰刀菌的影响 总被引：7，自引：0，他引：7
本试验以玉米青枯病病原肿囊腐霉(Pythium inflatum Malthews)与禾生腐霉(Pythium gramlnicola Subram)为材料,着重研究了两种腐霉的生长与代谢对其伴生病原禾谷镰刀菌(Fusarium graminearum Schw.)的影响,结果表明:1.腐霉的定殖生长能力弱于禾谷镰刀菌。在腐霉菌落上,禾谷镰刀菌仍可生长,而在禾谷镰刀菌菌落上,腐霉则不能生长。2.在伴生条件下,腐霉被镰刀菌覆盖的时间长短随接种间隔而有变化,接种间隔愈短,则覆盖愈快。3.两种腐霉的培养滤液均对禾谷镰刀菌的孢子萌发与芽管伸长及菌落扩展有明显的促进作用,表明滤液中含有对镰刀菌生长有利的活性成分。4.腐霉培养滤液对禾谷镰刀菌红色色素的产生有一定的抑制作用,其原因可能与腐霉的嗜糖性有关。5.田间结果表明,腐镰复合接种的发病率接近禾谷镰刀菌单菌接种,但低于腐霉单菌接种。 相似文献
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1978~1981年采集54个县市小麦病穗标样,单孢分离获1081菌株。经室内外综合鉴定明确本省引起小麦赤霉病的致病病原有禾谷镰刀菌(Fusarium gra-minearum Schwabe),雪腐镰刀菌[F.nival (Fr.) Ces.],本色镰刀菌(F.concolor Rg.),弯角镰刀菌(F.camptoceras Wr.&Rg.),串珠镰刀菌(F.moniliforme Sheld),硫色镰刀菌(F.sulphureum schecht Sacc.)和燕麦镰刀菌草类变种(F.avenaceum var.herberum)。其中禾谷镰刀菌分离频率最高,占绝对优势,分布遍及全省。7个种致病力测定,F=10.48,F> 0.01,不同种致病力差异极显著;禾谷镰刀菌、弯角镰刀菌和硫色镰刀菌致病力最强。 相似文献
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烟草镰刀菌根腐病病菌致病粗毒素的研究 总被引：1，自引：0，他引：1
本试验测定了经尖孢镰刀菌（Fusarium oxysporum）和茄病镰刀菌（F.solani）粗毒素浸泡后烟草幼苗抗病相关酶系的活性及细胞膜透性的变化,以研究毒素对烟草的致病作用。结果表明,引起烟草根腐病的尖孢镰刀菌和茄病镰刀菌的毒素属于非寄主专化性毒素（NHST）。烟草幼苗经毒素处理12～60 h,其过氧化物酶（peroxidase, POD）和多酚氧化酶（polyphenol oxidase, PPO）的活性都迅速升高,随后下降,幼苗出现不同程度的萎蔫。50%的毒素液处理幼苗根部54 h后,根部细胞膜的损伤率比对照均增加了80%,叶片的细胞膜损伤率比对照增加了90%。另外毒素处理能抑制烟草种子胚根的生长,使幼苗萎蔫,与病原菌直接接种表现相同,说明毒素是病原菌侵染烟草导致发病的一个重要因子。 相似文献
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H. J. M. Löffler J. R. Mouris 《European journal of plant pathology / European Foundation for Plant Pathology》1992,98(2):107-115
The production of phytotoxins byFusarium oxysporum f.sp.lilii, a pathogen causing bulb and scale rot in lilies, was investigated. To determine the toxic activity of culture filtrate, a bioassay with in vitro grown scale bulblets or with callus was set up. The fungus produces toxic components in different culture media. The highest toxicity was observed in Czapek Dox medium. HPLC and GC/MS analyses revealed the presence of fusaric acid at toxic concentrations in this medium. The production of fusaric acid in time coincides with the increase of toxic activity in the culture filtrate. It is concluded that at least part of this toxicity is due to fusaric acid. 相似文献
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The necrotrophic fungus Alternaria alternata f.sp. lycopersici produces AAL toxins that cause necrosis in tomato tissues with high specificity. Resistance or susceptibility of tomato to the fungus and insensitivity or sensitivity to AAL toxins are determined by a single locus, Asc . In order to investigate further the specificity of the host–fungus interaction, 200 species of Solanaceae were tested for their sensitivity to AAL toxins TA and TB . Twenty-five species were found to be sensitive to AAL toxins at a concentration of (0·2 µ m ) used for distinguishing sensitive and insensitive tomato plants. Three species were as sensitive as the sensitive tomato line, indicating that AAL toxins effectively act on a broader range of plant species within the Solanaceae. 相似文献
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ABSTRACT In search of new durable disease resistance traits in barley to control leaf spot blotch disease caused by the necrotrophic fungus Bipolaris sorokiniana (teleomorph: Cochliobolus sativus), we developed macroscopic and microscopic scales to judge spot blotch disease development on barley. Infection of barley was associated with cell wall penetration and accumulation of hydrogen peroxide. The latter appeared to take place in cell wall swellings under fungal penetration attempts as well as during cell death provoked by the necrotrophic pathogen. Additionally, we tested the influence of a compromised Mlo pathway that confers broad resistance against powdery mildew fungus (Blumeria graminis f. sp. hordei). Powdery mildew-resistant genotypes with mutations at the Mlo locus (mlo genotypes) showed a higher sensitivity to infiltration of toxic culture filtrate of Bipolaris sorokiniana as compared with wild-type barley. Mutants defective in Ror, a gene required for mlo-specified powdery mildew resistance, were also more sensitive to Bipolaris sorokiniana toxins than wild-type barley but showed less symptoms than mlo5 parents. Fungal culture filtrates induced an H2O2 burst in all mutants, whereas wild-type (Mlo) barley was less sensitive. The results support the hypothesis that the barley Mlo gene product functions as a suppresser of cell death. Therefore, a compromised Mlo pathway is effective for control of biotrophic powdery mildew fungus but not for necrotrophic Bipolaris sorokiniana. We discuss the problem of finding resistance traits that are effective against both biotrophic and necrotrophic pathogens with emphasis on the role of the anti-oxidative system of plant cells. 相似文献
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Thielaviopsis basicola has been shown to be a root pathogen of pea of considerable importance in Denmark. The fungus is only found in fields with one or more previous pea crops in the field history. In the dry and warm growing season of 1989 the fungus was found in 0·6% and 3·2% of the fields in two separate areas in Denmark. In the fields where T. basicola was detected the average disease severity index in plant samples was 51·8, whereas the average disease severity index in plant samples without the fungus was 27·0. The average yield of green peas was reduced from 5167 to 4171 kg/ha when T. basicola was present. For detection and isolation of T. basicola it is important to use a technique combining microscopic examination, a semi-selective medium and a dilution plate method. 相似文献
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L. M. DELSERONE K. McCLUSKEY D. E. MATTHEWS H. D. VANETTEN 《Physiological and Molecular Plant Pathology》1999,55(6):317
Previous studies have indicated that detoxification of their hosts' phytoalexins is a tolerance mechanism for some true fungi, but not the fungus-like Oomycota, and may be involved in determining the virulence of a pathogen. In the present study, the associations between demethylation of the pea phytoalexin pisatin, tolerance to pisatin, and virulence on pea were examined for 50 fungal isolates which represent 17 species of pathogens and nonpathogens of pea. All isolates ofPythium coloratum and P. irregulare failed to metabolize and were sensitive to pisatin, consistent with previous observations that members of the Oomycota generally lack the ability to metabolize and are sensitive to their hosts' phytoalexins. Among true fungi tested, the ability to demethylate pisatin was common, regardless of whether the particular isolate was pathogenic on pea or not. However, when the rate of pisatin demethylation was compared to virulence, all but one of the moderate to highly virulent isolates rapidly demethylated pisatin. In addition, the more rapidly demethylating isolates were generally more tolerant of pisatin. These results suggest that a specialized enzyme system for quickly detoxifying pisatin might be present in most pea pathogens. In previous studies a specific cytochrome P450 enzyme for demethylating pisatin was identified in the pea pathogen Nectria haematococca mating population VI, and genes (PDA genes) encoding that enzyme have been cloned from this fungus. When DNA specific for these genes was used to probe genomic DNA from other fungi that demethylate pisatin, significant hybridization was detected with only one fungus, the pea pathogen Fusarium oxysporum f. sp. pisi. If the other pea pathogens possess a specific cytochrome P450 system for detoxification of pisatin, the genes encoding these enzymes apparently share limited nucleotide similarity with N. haematococca PDA genes. 相似文献
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ABSTRACT Colletotrichum dematium, the causal agent of mulberry anthracnose, was examined to produce phytotoxins in vitro and in planta. Raw and autoclaved mulberry leaves infected with the fungus, as well as the fungus incubated with several solid or liquid media, were extracted with acetone. Extracts obtained from the fungus grown on raw and autoclaved mulberry leaves caused brown necrotic lesions on susceptible mulberry leaves when they were placed (10 mul) on the wounded adaxial surface. Whereas, no extracts obtained from media, except inoculated medium containing homogenized mulberry leaves, induced the necrosis, suggesting that the fungus produced phytotoxins in planta and that some components in mulberry leaves may be indispensable substrates for producing the toxins. The phytotoxins obtained from the diseased leaves induced necrosis on nonhost plants leaves as well as on mulberry leaves. The toxins were present in the border of anthracnose lesions on the leaves, and the sensitivity to the toxin correlated with that to the fungus infection in each susceptible or resistant mulberry cultivar. These results suggest that the phytotoxins are host nonspecific and play a role in fungal pathogenesis in the development of the lesions. Four toxic compounds were isolated and purified from anthracnose lesions. However, due to the low yield, the chemical structure of the compounds could not be identified. 相似文献
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Eleven soybean cultivars with different levels of susceptibility to virulent isolate SG915 ofCalonectria ilicicola were examined for reaction to metabolites produced by the isolate. When the culture filtrate from isolate SG915 was applied
to trifoliates from 11 cultivars, cvs. ‘Cajun’ and ‘Asgrow 7986’ exhibited reduced wilting severity. However, there was no
correlation between sensitivity to culture filtrate and susceptibility to the fungal isolate. Wilting severity on cv. ‘Riverside
699’ was greatest when trifoliates were treated with culture filtrates from isolates SG915 (highly virulent) and C31 (less
virulent). The dilution end-point for culture filtrates of virulent isolate SG915 was determined to be 1:8. Nonautoclaved
culture filtrates caused complete wilt of soybean trifoliates after 36 h, but autoclaved culture filtrates demonstrated a
reduced ability to wilt leaves. Electrolyte leakage from treated leaf tissues increased over time regardless of the concentrations
of culture filtrate tested. The greatest electrolyte losses were observed during the initial 30 min incubation of leaf tissues.
The highest concentration of culture filtrate (50%, v/v) induced more electrolyte loss than the low concentration (10%, v/v)
or control. These results suggest that toxic metabolites ofC. ilicicola may be involved in disease development with leaf symptom expression. 相似文献
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枯萎病菌毒素培养滤液对唐菖蒲幼苗毒性的初步研究 总被引：2，自引：0，他引：2
对唐菖蒲枯萎病菌进行了产毒培养基的筛选,研究毒素培养滤液对胚根生长的抑制作用、对幼苗根系活力的影响及对幼苗的致萎作用。结果表明：唐菖蒲枯萎病菌在Czapek培养基中培养15 d所产生的培养滤液对唐菖蒲胚根的抑制作用最强,胚根生长抑制率高达99.79%;而菌丝干重在PD培养基中培养13 d达到最高值1 242.27 mg;毒素培养滤液经121℃灭菌20 min后对唐菖蒲胚根仍有很强的抑制作用,表现出较高的热稳定性;与对照相比,毒素培养滤液能够显著降低唐菖蒲幼苗根系活力,随处理时间的延长和处理浓度的增加,萎蔫级数逐渐增加。说明枯萎病菌毒素培养滤液是唐菖蒲枯萎病的致病因子,可以利用其筛选唐菖蒲抗枯萎病品种。 相似文献
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水稻白叶枯病菌毒素的分离、生物测定及化学成份初步分析 总被引：5，自引：0，他引：5
采自山西太谷及安徽固镇小麦上两禾谷胞囊线虫群体对禾谷胞囊线虫致病型国际鉴别寄主A组内11个品种具有相同的反应型——除对小麦品种Capa有毒性外,对大麦四个品种(Emir,Ortolan,Siri和Morocco)、燕麦四个品种(Sun Ⅱ,Pusa hybrid bsl,Silva和A.stezilis I.76)以及小麦其它两个品种(Loros和Iskamish-k-2-Light)等均无毒性,与目前世界上已正式命名的13个致病型不同,而与瑞典的Knislingc和Ringaascn两禾谷胞囊线虫群体的致病型相似,但也存在一定差异,瑞典的两群体对Morocco有毒性,而太谷和固镇两群体对Morocco无毒性。 相似文献