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1.
S. Mahadevakumar C. Chandana Y. S. Deepika K. S. Sumashri Vandana Yadav G. R. Janardhana 《European journal of plant pathology / European Foundation for Plant Pathology》2018,151(4):1081-1087
A severe outbreak of southern blight disease of China aster was observed during the post rainy season (September–November 2015) in the Mysore and Mandya Districts of Karnataka, Southern India. The disease incidence ranged between 12 and 47%. The typical disease symptoms include water-soaked lesions on leaves, stems and on the lower stem surfaces followed by quick wilting of the whole plant with abundant production of sclerotia near the stem-soil interface. The associated fungal pathogen was isolated on potato dextrose agar (PDA) medium, on which numerous reddish-brown sclerotia were seen. A total of 26 fungal isolates were isolated and studied for the mycelial compatibility. Isolate SrCCM 1 was used for pathogenicity analysis. The results of the study showed that, there was no variation among the isolates tested. Molecular identification of the pathogen by ITS-rDNA sequences of S. rolfsii showed 100% similarity with reference sequences. Based on the cultural, morphological and molecular characteristics, the fungal pathogen was identified as Sclerotium rolfsii Sacc. (Sexual morph: Athelia rolfsii (Curzi) C.C. Tu & Kimbr). Pathogenicity tests were performed on healthy leaves, roots and stems. Typical disease symptoms on leaves, stems and roots were evident after 5, 8 and 10 days of post-inoculation. Sclerotium rolfsii is known to cause diseases in economically important crop plants. However, no reports are available on the occurrence of S. rolfsii on China aster in India. 相似文献
2.
Appolinaire Adandonon Thierry Regnier Theresa A. S. Aveling 《European journal of plant pathology / European Foundation for Plant Pathology》2017,149(2):245-251
The role of phenolics in plant tolerance to pathogen infection is well documented. The objective of the present preliminary investigation was to study phenolic metabolites involved in the tolerance or susceptibility of cowpea (Vigna unguiculata Walp.) cultivars to Sclerotium rolfsii Sacc. and to use their presence as a possible screening tool. Total, free acid, ester-bound and cell wall-bound phenolics of 10 cowpea cultivars were quantified. In healthy seedlings, the tolerant cultivars displayed the higher phenol content than the susceptible cultivars. In S. rolfsii infected seedlings, the highest increase was found from 48 h after inoculation. The net effect of inoculation was a 630% increase in total phenolics (soluble and insoluble) in the stem of tolerant cultivars while the total phenolic content increased only by 212% in the stems of susceptible cultivars. Although, no significant difference (P = 0.05) was detected among cultivars, in terms of free acid phenolics, the amount of ester-bound and cell wall-bound phenolics significantly increased, therefore demonstrating a similar trend to the one observed for the total phenolic content. These preliminary results showed that the presence of phenolics before and after S. rolfsii infection may be used as a rapid screening method for detection of tolerance to S. rolfsii damping-off and stem rot of cowpea. 相似文献
3.
E. F. Abd-Allah 《Phytoparasitica》2005,33(5):460-466
Sclerotium rolfsii Sacc. was the cause of both the spoilage and the reduction in quality of peanut seeds as well as the decrease in quality
and quantity of the oil during pathogenesis. The application of a biocontrol agent,Bacillus subtilis, counteracted the negative effect of the seedborne pathogen (S. rolfsii) on the chemical and physical properties of the oil content. Moreover, the changes in fatty acids composition of peanut seed
oil have been related to a tolerance mechanism againstS. rolfsii and to the induction of systemic physiological changes which result in greater improvement of oil quality and quantity. 相似文献
4.
Damping-off and stem rot are two types of diseases affecting cowpea (Vigna unguiculata (L.) Walp.) in the Quémé Valley, Benin. Of the fungal species isolated from diseased plants in the field during a 2-year
experiment (2001 and 2002),Sclerotium rolfsii Sacc. was found to be solely responsible for these diseases. The disease incidence decreased with increasing distance of
the field from the river. Measurement ofS. rolfsii initial inoculum, soil moisture and disease incidence in cowpea field plots revealed a positive correlation among these parameters.
The multiple regression analysis showed that the disease incidence increase was 0.4% for one unit increase in soil moisture
percent, whereas the disease incidence increase was 19.8% for one unit increase of the density of initial inoculum of the
pathogen. This is the first comprehensive study of the effects of environmental factors on the incidence of cowpea damping-off
and stem rot caused byS. rolfsii in Benin, and shows that the density of the initial inoculum is the main contributing factor of the disease in the field
in the Quémé Valley.
http://www.phytoparasitica.org posting Dec. 19, 2004. 相似文献
5.
Patricia Guzmán-Valle Leticia Bravo-Luna Roberto Montes-Belmont César Guigón-López Gabriela Sepúlveda-Jiménez 《European journal of plant pathology / European Foundation for Plant Pathology》2014,138(2):223-229
We evaluated the ability of Trichoderma asperellum Samuels, Lieckfeldt & Nirenberg to induce resistance to the fungal plant pathogen, Sclerotium rolfsii Saccardo, in three onion (Allium cepa L.) varieties. Both the severity of disease and the activities of glucanase, chitinase and peroxidase (enzymes involved in plant resistance) were evaluated in onions inoculated with T. asperellum alone, S. rolfsii alone, or both T. asperellum and S. rolfsii (dual-inoculation) and compared to uninoculated (control) plants. In dual inoculations, the presence of T. asperellum reduced the severity of disease symptoms caused by S. rolfsii. Inoculation with T. asperellum alone increased glucanase, chitinase and peroxidase activity in bulbs, roots and leaves of all three onion varieties compared to uninoculated controls; bulbs of the variety Red Satan (RS) had the highest enzyme activity. In plants inoculated with S. rolfsii alone, enzyme activity was only increased in bulbs and roots compared to uninoculated controls. The highest levels of enzyme activity also occurred only in bulbs and roots of plants that had been dual-inoculated with T. asperellum and S. rolfsii. Plants of the RS variety showed the highest enzyme activities (both constitutive and induced) and showed the lowest severity of disease. Therefore, application of T. asperellum has potential as a biological control alternative to synthetic fungicides for protection of onion crops against infection by S. rolfsii. This protection depends on both constitutive and induced defence responses and varies amongst onion varieties. 相似文献
6.
7.
白绢病(Sclerotium rolfsii Sacc。)是中药白术上的一种严重病害。白术主产区常年损失颇为严重。杭州地区白术白绢病从5月上旬开始发生,一直延续到9月下旬,6～8月较重。被害白术,药用根茎腐烂,植株凋萎枯死。在浙江除白术受害外,还发现有12个科25种药用植物被此病为害。其中菊芋、玄参、乌头和黄芪受害最重。遗留在土中的菌核、种用病术、带菌肥料是此病的主要初次侵染来源。高温多湿有利白绢病的发生;施用牛粪、垃圾有加重发病的趋势;低坡地比高坡地、水田比旱地发病要重;连作、株行距小的病情重。用1%石灰液浸菌核2小时及大田每株用石灰粉2.5克,拌接菌核土壤试验,效果显著;0.5%硫酸铜液浸菌核和白术田浇治(100毫升/株)效果也较好。 相似文献
8.
Thirteen fungal species were isolated from diseased plants of Striga hermonthica (Del.) Benth in northern Ghana. The pathogenicity of 12 isolates of the fungal species including Curvularia fallax Boed, Fusarium equiseti (Corda) Sacc., Fusarium equiseti var. bullatum (Sherb.) Wollenw., F. oxysporum Schlecht, F. solani (Mart) Sacc., Macrophonuina phasealina (Tassi) Goidan, and Sclerotium rolfsii (Sacc.) were evaluated against S. hermonthica under controlled environmental conditions. All isolates were pathogenic to S. hermonthica when propagated on wheat (Triticum aestivum L.) grains and incorporated pre-planting into the soil. However, their virulence differed. Two isolates of F. oxysporum and one isolate of F. solani reduced the emergence of S. hermonthica by 88%, 98%, and 76%, respectively. Sorghum (Sorghum bicolor (L.) Moench) yield was increased by 26% when S. hermonthica was controlled. In contrast, in the control treatment with S. hermonthica no yield could be obtained. The F. oxysporum isolates were not pathogenic on sorghum. Germination tests indicated that the F. oxysporum isolates were highly pathogenic to S. hermonthica seeds. Although the F. solani isolate reduced the emergence of S. hermonthica in the pot experiments, it did not influence germination. This indicates that pathogens may attack different stages in the life cycle of S. hermonthica. 相似文献
9.
Twig cankers and diebacks were observed on cherry laurel (Prunus laurocerasus L.) hedges located in a private garden of Perugia (Central Italy). Four fungal isolates, forming gray colonies and aerial mycelium, were obtained from cankers. For each isolate, Koch’s postulates were fulfilled by inoculating cherry laurel plants. Based on cultural characteristics, rep-PCR and phylogenetic analyses on ITS and EF1-α nucleotides sequences, the isolates were identified as Diplodia seriata De Not. To the best of our knowledge, this is the first report of D. seriata as a new pathogen of P. laurocerasus. The severe symptoms and the wide distribution of the host plant make the pathogen potentially dangerous for this ornamental species. 相似文献
10.
MARTIN J. BARBETTI 《Plant pathology》1985,34(1):49-53
A wide range of fungi was recorded from leaves and petioles of subterranean clover ( Trifolium subterraneum L.), with and without symptoms of disease, in Western Australia. Leptosphaerulina trifolii (Rostrup) Petrak and Phoma medicaginis Malb. & Roum. were the two most frequently isolated fungi. Ascochyta caulicola Lamb., Colletotrichum truncatum (Schw.) Andus & Moore, Curvularia trifolii (Kauffm.) Boedijn., Fusarium avenaceum (FR.) Sacc, Myrothecium verrucaria (Fr.) Sacc, Phoma medicaginis , and Stemphylium globuliferum (Vestergr.) Simmons were new records on subterranean clover foliage in Western Australia. Phoma medicaginis was demonstrated to be pathogenic and this is the first record as a pathogen on subterranean clover foliage in Western Australia, M. verrucaria and F. avenaceum caused leaf spotting or more extensive lesions as a consequence of undetermined phytotoxic products produced on agar plate cultures. 相似文献
11.
梨胶锈菌的重寄生菌研究Ⅳ重寄生菌的越冬、传播及侵入 总被引：1，自引：0，他引：1
本文报道了梨胶锈菌(Gymnosporangium asiaticum Miyabe ex Yamada)的重寄生菌(Tuberculina vinosa Sacc.)越冬、传播及侵入的研究结果。重寄生菌在自然条件下以分生孢子在其寄生部位越冬;经150天后,其孢子萌发率为29.5%;分生孢子随气流传播;孢子萌发形成芽管经性子器口和锈子器口侵入,不能直接侵入;完成侵入所需最短时间为10小时;在14~12℃下,潜育期为12~7天。在梨胶锈菌发生期,重寄生菌可发生多次再侵入。 相似文献
12.
Activities of polygalacturonase, pectin lyase, and cellulase increased in susceptible, catechol-treated, and resistant tomato plants, after inoculation withFusarium oxysporum f.lycopersici (Sacc.) Snyder and Hansen race 2. The catechol-treated and the resistant plants remained symptomless, while susceptible plants developed symptoms of disease. It is therefore suggested that increased activity of cell-wall-degrading enzymes in inoculated plants does not necessarily cause the development of disease symptoms. 相似文献
13.
芦荟根腐病病原菌的鉴定 总被引：8，自引：0，他引：8
芦荟是百合科多年生常绿多肉质草本植物，原产于非洲热带沙漠干旱地区，是一种古老而神奇的植物。随着芦荟的医疗、保健作用逐渐被人们所认可，70年代以来，美国、日本、韩国等国家相继掀起了”芦荟热”。我国芦荟产业从80年代末开始起步，近几年来全国31个省市自治区除西藏外均有栽培，尤以海南、云南、福建和广东省等地较为集中。据不完全统计，全国芦荟种植面积为800km^2左右。但是随着芦荟大规模的种植，其根腐病的发生也日愈严重，威胁到芦荟种植业的发展。2004年，大面积田间抽样调查结果显示，该病在云南省的发病率为42．54％、死亡率为26．36％。对于芦荟根腐病病原菌的研究，国内外还没有报道，本文对引起云南省芦荟根腐病的病原菌进行了系统的鉴定。 相似文献
14.
云南葡萄产区葡萄炭疽病病原鉴定及致病力分析 总被引：11，自引：6，他引：5
为了明确引起云南葡萄产区炭疽病的病原种类,利用形态鉴定和特异性引物分子检测相结合的方法对从云南省主要葡萄产区采集的60株炭疽病菌菌株进行了鉴定。葡萄炭疽病菌菌株的菌落形态和生长速率与对照菌株尖孢炭疽菌Colletotrichum acutatum差异不明显,但其分生孢子大小显著小于尖孢炭疽菌,附着胞深褐色,球形或不规则形。胶孢炭疽菌Colletotrichum gloeosporioides特异性引物CgInt/ITS4从供试葡萄炭疽病菌菌株基因组DNA中扩增出1条约500 bp的特异性条带,而尖孢炭疽菌特异性引物CaInt2/ITS4对葡萄炭疽病菌无扩增条带。研究表明,引起云南葡萄主产区炭疽病的病原为胶孢炭疽菌;供试胶孢炭疽菌对红提葡萄均有致病力,但菌株致病力差异较大,对番茄和草莓存在交叉侵染的能力,且对多菌灵的敏感性较尖孢炭疽菌高。 相似文献
15.
Nitric oxide (NO) donors Nitroso-R-Salt, 2-Nitroso-1-Naphthol and Sodium Nitro Prusside (SNP) were evaluated for their effectiveness in protecting pearl millet [(Pennisetum glaucum L.) R. Br.] plants against downy mildew disease caused by Sclerospora graminicola [(Sacc). Schroet]. Optimization experiments with NO donors showed no adverse effect either on the host or pathogen. Aqueous SNP seed treatment with or without polyethylene glycol (PEG) priming was the most effective in inducing the host resistance against downy mildew both under greenhouse and field conditions. Potassium Ferrocyanide, a structural analog of NO donor lacking NO moiety failed to protect the pearl millet plants from downy mildew indicating a role for NO in induced host resistance. Spatio-temporal studies corroborated that the protection offered by NO donor treatment was systemic in nature and a minimum of 3-day time gap between the inducer treatment and subsequent pathogen inoculation was necessary for maximum resistance development. Disease protection ability of NO donors was also validated as durable in nature. Conversely, prior-treatment with NO scavenger 2-4-carboxyphenyl-4,4,5,5 tetrazoline-1-oxyl-3-oxide potassium salt (C-PTIO) rendered the pearl millet plants relatively susceptible for pathogen infection. Expression of primary defense responses like hypersensitive response, lignin deposition and defense related enzyme phenylalanine ammonialyase −EC 4.3.1.5 (PAL) were enhanced by NO donor treatments. 相似文献
16.
Chutsuda Junsopa Sanun Jogloy Weerasak Saksirirat Patcharin Songsri Thawan Kesmala Barbara B. Shew 《European journal of plant pathology / European Foundation for Plant Pathology》2018,151(1):251-255
Stem rot caused by Sclerotium rolfsii is an important problem for Jerusalem artichoke production. Host plant resistance is the most promising method to control disease. If resistant genotypes can be identified in seedlings and this resistance is closely related to resistance at maturity, the evaluation of disease resistance in adult plants could be curtailed or omitted, increasing the speed and efficiency of screening. The objective of this study was to determine the relationship between resistance to S. rolfsii in Jerusalem artichoke in seedling and in adult stages under field conditions. Field experiments were set up in different soil fertility environments in the rainy season during July to October 2014. In each environment, 10 varieties of Jerusalem artichoke with differences in resistance to S. rolfsii were planted and inoculated either 15 or 45 days after transplanting. Higher disease incidence was observed on adult plant stage, but disease severity was similar for both plant stages. The correlations between seedling and adult responses were positive and significant for disease incidence, area under disease progress curve and severity index. Screening for resistance to S. rolfsii in Jerusalem artichoke can be carried out on seedlings, thus improving the efficiency of selection. 相似文献
17.
BACKGROUND: Management of early leaf spot (Cercospora arachidicola Hori.), late leaf spot [Cercosporidium personatum (Berk. & MA Curtis) Deighton] and stem rot (Sclerotium rolfsii Sacc.) of peanut (Arachis hypogaea L.) in the southeastern USA is heavily dependent upon sterol biosynthesis inhibitor (SBI) and quinone outside inhibitor (QoI) fungicides. Effective new fungicides with different modes of action could improve overall disease control and extend the utility of the current fungicides. Penthiopryad is a pyrazole carboxamide fungicide being evaluated for use on peanut. Field experiments were conducted from 2004 to 2007 to determine the effect of a range of rates (0–0.36 kg AI ha?1) of penthiopyrad on leaf spot and stem rot and the relative efficacy of penthiopyrad and current fungicide standards chlorothalonil, tebuconazole and azoxystrobin. RESULTS: Leaf spot control in plots treated with penthiopyrad at 0.20 kg AI ha?1 or higher was similar to or better than that for the chlorothalonil standard. The incidence of stem rot for all penthiopyrad treatments was usually less than that for the tebuconazole or azoxystrobin standard treatments. Pod yields for all penthiopyrad treatments were similar to or higher than those for the respective standards. CONCLUSION: Penthiopyrad has excellent potential for management of late leaf spot and stem rot of peanut, and may complement current SBI and QoI fungicides. Copyright © 2008 Society of Chemical Industry 相似文献
18.
Zs. D. Rozsnyay 《EPPO Bulletin》1977,7(1):69-80
Cytosporal canker and dieback (Cytospora cincta Sacc.) is a widespread disease in apricot growing areas of Europe, excluding the Mediterranean. The pathogen attacks xylem and phloem. If the necrotic phloem completely girdles the branches or trunk, the section above the girdled region dies. When cambium necrosis does not girdle the branch or trunk, canker development ensues. Apricot trees are susceptible to Cytospora infection between July and the next bud opening. 相似文献
19.
粟白发病抗病性研究Ⅱ我国粟白发病菌生理小种及其分布 总被引：1，自引：1，他引：0
1988~1993年在北京用采自中国4个谷子生态区白发病菌[Sclerospora graminicola(Sacc.) Schröt.]标样,以新创造的单病株(系)卵孢子菌土种子包衣接种法研究了我国粟白发病菌的生理小种。结果显示,白发病菌株与粟品种间有强互作反应,说明粟白发病菌的致病力有特异性。经选择,确定三三二、西城白、大青苗、柳条青和189等5个品种为一套适宜于测试粟白发病菌生理小种的鉴别品种。根据68个参试菌株在5个鉴别品种上的反应特征,初步将我国白发病菌区分为6群20个生理小种,并明确了各小种在各生态区的分布,我国4个谷子生态区中,黄土高原病菌小种类群最多,致病力也较强。 相似文献
20.
Histological and histochemical characteristics of leaves from resistant and susceptible groundnut genotypes (Arachis hypogaea L.) were observed after inoculation withCercospora arachidicola Hori andCercosporidium personatum (Berk. and Curt.) Deighton. Both the pathogens induced almost similar anatomical responses in the inoculated leaves. The epidermal and mesophyll cells were shrunken or collapsed; damage to protoplasts was more obvious than damage to cell walls. The histochemical localizations revealed a gradual depletion of polysaccharides, proteins, ascorbic acid, and nucleic acids from the diseased host tissue at the site of contact with the pathogen and their subsequent accumulation in the pathogen in the later stages of disease development. Differential staining for these metabolites was not observed in healthy tissues of these genotypes. 相似文献