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Sample records for monosporascus root rot

  1. Root transcriptional responses of two melon genotypes with contrasting resistance to Monosporascus cannonballus (Pollack et Uecker infection

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    Roig Cristina

    2012-11-01

    Full Text Available Abstract Background Monosporascus cannonballus is the main causal agent of melon vine decline disease. Several studies have been carried out mainly focused on the study of the penetration of this pathogen into melon roots, the evaluation of symptoms severity on infected roots, and screening assays for breeding programs. However, a detailed molecular view on the early interaction between M. cannonballus and melon roots in either susceptible or resistant genotypes is lacking. In the present study, we used a melon oligo-based microarray to investigate the gene expression responses of two melon genotypes, Cucumis melo ‘Piel de sapo’ (‘PS’ and C. melo ‘Pat 81’, with contrasting resistance to the disease. This study was carried out at 1 and 3 days after infection (DPI by M. cannonballus. Results Our results indicate a dissimilar behavior of the susceptible vs. the resistant genotypes from 1 to 3 DPI. ‘PS’ responded with a more rapid infection response than ‘Pat 81’ at 1 DPI. At 3 DPI the total number of differentially expressed genes identified in ‘PS’ declined from 451 to 359, while the total number of differentially expressed transcripts in ‘Pat 81’ increased from 187 to 849. Several deregulated transcripts coded for components of Ca2+ and jasmonic acid (JA signalling pathways, as well as for other proteins related to defence mechanisms. Transcriptional differences in the activation of the JA-mediated response in ‘Pat 81’ compared to ‘PS’ suggested that JA response might be partially responsible for their observed differences in resistance. Conclusions As a result of this study we have identified for the first time a set of candidate genes involved in the root response to the infection of the pathogen causing melon vine decline. This information is useful for understanding the disease progression and resistance mechanisms few days after inoculation.

  2. Disease notes - Bacterial root rot

    Science.gov (United States)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  3. Root rot in sugar beet piles at harvest

    Science.gov (United States)

    Sugar beet root rots are not only a concern because of reduced yields, but can also be associated with losses in storage. Our primary sugar beet root rot disease problem in the Amalgamated production area is Rhizoctonia root rot. However, this rot frequently only penetrates a short distance past t...

  4. Sugarbeet root rot in drought conditions

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    Jasnić Stevan M.

    2005-01-01

    Full Text Available In recent years several types of sugarbeet root rot have occurred in our country causing significant economic damage. The most frequent symptoms are leaf chlorosis and brown-black wet necrosis of the root. The necrosis spread through the entire root and vascular strands. In the course of this study F. oxysporum was the most frequently isolated from infected sugar beet roots. The incidence of other fungi (Fusarium solani, Rhizoctonia solani and Macrophomina phaseolina was much lower and it depended on weather conditions. High temperatures occurring during dry years encourage the development of F. oxysporum, the causer of sugar beet root rot. In 2000, an extremely dry year, plant vitality was satisfactory in the experiment with irrigation and the average root rot incidence was low (2,91%. In the nonirrigated variant the average incidence was high (71,02%. It may be concluded on the basis of the results from five years (2000-2004 that the major causal agents of sugarbeet root rot in our country are species from genus Fusarium, especially F. oxysporum. Fusarium wilt and root rot are due to the increased frequency of dry and warm years.

  5. Etiology of phomopsis root rot in soybean

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    Valéria Cecília Ghissi

    2014-09-01

    Full Text Available In a survey of damages caused by soybean root rot to crops in the south of Brazil for several years, a root rot caused by Phomopsis sp has been found with increasing frequency. The primary symptoms are seen when the main root is cut longitudinally, including the death of the wood which shows white coloration and well-defined black lines that do not have a defined format. Thus, based on similarity, it has been called geographic root rot due to its aspect resembling irregular lines that separate regions on a map. In isolations, colonies and alpha spores of Phomopsis have prevailed. Pathogenicity test was done by means of inoculation in the crown of plants cultivated in a growth chamber. The geographic symptoms were reproduced in plants and the fungus Phomopsis sp. was reisolated. In soybean stems naturally infected with pod and stem blight, geographic symptoms caused by Phomopsis phaseoli are found. To the known symptoms on stems, pods and grains, that of root rot caused by P. phaseoli is now added.

  6. Response of the Andean diversity panel to root rot in a root rot nursery in Puerto Rico

    Science.gov (United States)

    The Andean Diversity Panel (ADP) was evaluated under low-fertility and root rot conditions in two trials conducted in 2013 and 2015 in Isabela, Puerto Rico. About 246 ADP lines were evaluated in the root rot nursery with root rot and stem diseases caused predominantly by Fusarium solani, which cause...

  7. MANAGEMENT OF ROOT ROT IN AVOCADO TREES

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    SIMONE RODRIGUES DA SILVA

    Full Text Available ABSTRACT Root rot (Phytophthora cinnamomi Rands is one of the most restrictive factors to avocado growing in main producing regions worldwide. In Brazil, scientific reports on the effectiveness of control methods are scarce. The objective of this study was to evaluate the efficiency of gypsum applications and dolomitic limestone to the soil and potassium phosphite sprays in controlling this disease in ‘Hass’ avocado, grown without irrigation. The application of dolomitic limestone or gypsum alone is not effective to recover plants affected by root rot. The application of potassium phosphite, combined or not with dolomitic lime or gypsum enables the partial recovery ‘Hass’ avocado plants affected by the disease.

  8. A diagnostic guide for Fusarium Root Rot of pea

    Science.gov (United States)

    Fusarium root rot, caused by Fusarium solani f. sp. pisi, is a major root rot pathogen in pea production areas worldwide. Here we provide a diagnostic guide that describes: the taxonomy of the pathogen, signs and symptoms of the pathogen, host range, geographic distribution, methods used to isolate ...

  9. Root rot diseases of sugar beet

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    Jacobsen Barry J.

    2006-01-01

    Full Text Available Root rot diseases of sugar beet caused by Rhizoctonia solani (AG 2-2 IIIB and AG 2-2 IV, R. crocorum, Aphanomyces cochlioides, Phoma betae, Macrophomina phaeseolina, Fusarium oxysporum f.sp. radicis-betae, Pythium aphanidermatum Phytophthora drechsleri, Rhizopus stolonifer, R. arrhizus and Sclerotium rolfsii cause significant losses wherever sugar beets are grown. However, not all these soil-borne pathogens have been reported in all sugar beet production areas. Losses include reduced harvestable tonnage and reduced white sugar recovery. Many of these pathogens also cause post harvest losses in storage piles. Control for diseases caused by these pathogens include disease resistant cultivars, avoidance of stresses, cultural practices such as water management and the use of fungicides.

  10. Etiology and Epidemiological Conditions Promoting Fusarium Root Rot in Sweetpotato.

    Science.gov (United States)

    Scruggs, A C; Quesada-Ocampo, L M

    2016-08-01

    Sweetpotato production in the United States is limited by several postharvest diseases, and one of the most common is Fusarium root rot. Although Fusarium solani is believed to be the primary causal agent of disease, numerous other Fusarium spp. have been reported to infect sweetpotato. However, the diversity of Fusarium spp. infecting sweetpotato in North Carolina is unknown. In addition, the lack of labeled and effective fungicides for control of Fusarium root rot in sweetpotato creates the need for integrated strategies to control disease. Nonetheless, epidemiological factors that promote Fusarium root rot in sweetpotato remain unexplored. A survey of Fusarium spp. infecting sweetpotato in North Carolina identified six species contributing to disease, with F. solani as the primary causal agent. The effects of storage temperature (13, 18, 23, 29, and 35°C), relative humidity (80, 90, and 100%), and initial inoculum level (3-, 5-, and 7-mm-diameter mycelia plug) were examined for progression of Fusarium root rot caused by F. solani and F. proliferatum on 'Covington' sweetpotato. Fusarium root rot was significantly reduced (P Fusarium spp. revealed the production of fumonisin B1 by F. proliferatum when infecting sweetpotato. This study is a step toward characterizing the etiology and epidemiology of Fusarium root rot in sweetpotato, which allows for improved disease management recommendations to limit postharvest losses to this disease.

  11. Root rot of sugarbeet in the Vojvodina Province

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    Stojšin Vera B.

    2006-01-01

    Full Text Available Large changes introduced in the sugar beet production technology in the Vojvodina Province over last 40 years resulted in changes in the etiology and harmfulness of different agents of sugar beet root diseases. Improvements in cultivation practices reduced the harmfulness of some diseases while increased the harmfulness of others. Some disease agents became obsolete, but others gained importance. New agents of root diseases were found. The most frequent damages, persisting over long periods of time were caused by seedling damping-off, Fusarium root rot, charcoal root rot, parasitic (Rhizomania and non-parasitic root bearding. The parasitic damping-off caused by several fungal species but most frequently by Phoma betae occurred at the time when multigerm seeds were used in combination with extensive cultural practices. The agents of seedling diseases completely lost their significance as the consequence of switching to fungicide - treated monogerm seeds, earlier planting and improved soil tillage. In the period of intensive use of agricultural chemicals, seedling damping-off occurred frequently due to the phytotoxic action of chemicals (insecticides, herbicides and mineral fertilizers. In some years, frosts caused damping- off of sugar beet seedlings on a large scale in the Vojvodina Province. Poor sugar beet germination and emergence were frequently due to spring droughts. Sometimes they were due to strong winds. The occurrence of Fusarium root rot and charcoal root rot intensified on poor soils. Fusariosis symptoms were exhibited as plant wilting and different forms of root rot. In recent years root tip rot has occurred frequently in the first part of the growing season causing necrosis and dying of plants. Lateral roots tended to proliferate from the healthy tissue, giving the root a bearded appearance similar to Rhizomania. Fusarium oxysporum was the most frequent agent of this fusariosis. F. graminearum, F. equiseti, F. solani have also been

  12. Molecular systematics of the cotton root rot pathogen, Phymatotrichopsis omnivora

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    Marek, S.M.; Hansen, K.; Romanish, M.; Thorn, R.G.

    2009-01-01

    Cotton root rot is an important soilborne disease of cotton and numerous dicot plants in the south-western United States and Mexico. The causal organism, Phymatotrichopsis omnivora (= Phymatotrichum omnivorum), is known only as an asexual, holoanamorphic (mitosporic) fungus, and produces conidia

  13. Phytophthora root rot resistance in soybean E00003

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    Phytophthora root rot (PRR), caused by the oomycete Phytophthora sojae, is a devastating disease in soybean production. Using resistant cultivars has been suggested as the best solution for disease management. Michigan elite soybean E00003 is resistant to P. sojae and has been used as a PRR resist...

  14. Susceptibility of highbush blueberry cultivars to Phytophthora root rot

    Science.gov (United States)

    Phytophthora cinnamomi Rands is a ubiquitous soilborne pathogen associated with root rot in many woody perennial plant species, including highbush blueberry (Vaccinium sp.). To identify genotypes with resistance to the pathogen, cultivars and advanced selections of highbush blueberry were grown in a...

  15. Molecular systematics of the cotton root rot pathogen, Phymatotrichopsis omnivora

    NARCIS (Netherlands)

    Marek, S.M.; Hansen, K.; Romanish, M.; Thorn, R.G.

    2009-01-01

    Cotton root rot is an important soilborne disease of cotton and numerous dicot plants in the south-western United States and Mexico. The causal organism, Phymatotrichopsis omnivora (= Phymatotrichum omnivorum), is known only as an asexual, holoanamorphic (mitosporic) fungus, and produces conidia res

  16. Identification of soil-borne pathogens in a common bean root rot nursery in Isabela, Puerto Rico

    Science.gov (United States)

    Limited research has been completed on the root rot complex of the common bean (Phaseolus vulgaris L.) in the Caribbean, while yield losses of over 50% due to root rot disease have been reported worldwide. In this study, the predominant root rot pathogens in a 40-year old common bean root rot nurser...

  17. The occurrence of root rot and crown rot of rice in Gilan and Zanjan provinces, Iran.

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    Saremi, H; Okhovat, S M

    2004-01-01

    Root rot and crown rot of rice is one of the important fungal diseases of rice in Gilan and Zanjan provinces, Iran. During 1999--2002, samples of plant and soil around the roots of infected rice plants were collected and used to identify the causal agent. Root and crown parts were surface sterilized with sodium hypochlorite and then cultured on PDA (potato dextrose agar), PPA (pepton pentacholoritobenzene agar) and CLA (carnation leaf agar) media. Soil samples prepared in water agar were used to isolate the pathogen. The causal agent was identified as Fusarium moniliforme. Colonies were initially white but turned violet to grey late. Microconidia were arranged in chain and macroconidia were cylindrical and long with 3-5 septa. The disease was severe in Zanjan province particularly along Ghezel Ozan river where the infection ranged from 70-80%. Root and crown rot was more prevalent in areas where Champa and Gerdeh were being cultivated continuously. On the other hand, Sadri cultivars had relatively less infection. Persistent cultivation of rice and seed sowing method intensified disease development and caused significant economic losses.

  18. An integrated control of Pythium root rot of greenhouse tomato.

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    Tu, J C

    2002-01-01

    Pythium root rot caused by Pythium aphanidermatum is one of the most important diseases of greenhouse tomatoes. Hydroponic culture exacerbates the problem. Both nutrient film technique (NFT) and recirculating growing systems pose a challenge in the control of this disease, because the pathogen, especially the zoospores, can spread easily in the recirculating solution to the whole growing system. Fortunately, hydroponically grown plants are easier to manipulate than soil grown plants, proper manipulation of root environments can lead to excellent disease control. This paper reports the development of an effective integrated control measure for pythium root rot of tomato by integrating pH, bioagent, and ultra-violet irradiation in a specific manner. This integrated control consists of three operations: a) before transplanting, the UV system is connected to sterilize the recirculating solution using 100 mJcm-2; b) after transplanting, the nutrient solution is delivered at pH 5.0 regime for five weeks followed by adjusting pH to 5.8 to 6.2 regime for one week; and c) bacterial bioagent, such as Pseudomonas is introduced into the root zone at 100 mL per plant at 10(8) bacteria mL-1 or added to the nutrient solution to arrive at 10(6) bacteria mL-1 in the solution. This report also discusses the advantages and limitations of this measure in the control of pythium root rot.

  19. Survival of southern highbush blueberry cultivars in Phytophthora Root Rot Infested fields in South Mississippi

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    Phytophthora root rot is an important disease of commercial blueberries and is most severe when blueberries are grown in wet soils with poor drainage. Symptoms of Phytophthora root rot include small, yellow or red leaves, lack of new growth, root necrosis, and a smaller root system than healthy plan...

  20. Trichoderma spp. decrease Fusarium root rot in common bean

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    Hudson Teixeira

    2012-12-01

    Full Text Available The effectiveness of six Trichoderma-based commercial products (TCP in controlling Fusarium root rot (FRR in common bean was assessed under field conditions. Three TCP, used for seed treatment or applied in the furrow, increased seedling emergence as much as the fungicide fludioxonil. FRR incidence was not affected, but all TCP and fludioxonil reduced the disease severity, compared to control. Application of Trichoderma-based products was as effective as that of fludioxonil in FRR management.

  1. Resistance to Fusarium dry root rot disease in cassava accessions

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    Saulo Alves Santos de Oliveira

    2013-10-01

    Full Text Available The objective of this work was to identify sources of resistance to dry root rot induced by Fusarium sp. in cassava accessions. A macroconidial suspension (20 µL of 11 Fusarium sp. isolates was inoculated in cassava roots, from 353 acessions plus seven commercial varieties. Ten days after inoculation, the total area colonized by the pathogen on the root pulp was evaluated by digital image analysis. Cluster analysis revealed the presence of five groups regarding resistance. The root lesion areas ranged from 18.28 to 1,096.07 mm² for the accessions BGM 1518 and BGM 556, respectively. The genotypes BGM 1042, BGM 1552, BGM 1586, BGM 1598, and BGM 1692 present the best agronomical traits.

  2. Mapping Fusarium solani and Aphanomyces euteiches root rot resistance and root architecture quantitative trait loci in common bean (Phaseolus vulgaris)

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    Root rot diseases of bean (Phaseolus vulgaris L.) are a constraint to dry and snap bean production. We developed the RR138 RIL mapping population from the cross of OSU5446, a susceptible line that meets current snap bean processing industry standards, and RR6950, a root rot resistant dry bean in th...

  3. Efficacy of management tools for control of Pythium root rot of Douglas fir seedlings, 2010

    Science.gov (United States)

    This study investigated the efficacy of management tools for control of Pythium root rot of Douglas fir seedlings. This effort was conducted as part of the IR-4 Ornamental Horticulture program to evaluate fungicides and biopesticides for management of root, crown and stem rot of ornamental plants ca...

  4. Interaction of Rhizoctonia solani and Rhizopus stolonifer Causing Root Rot of Sugar Beet

    Science.gov (United States)

    In recent years, growers in Michigan and other sugar beet production areas of the United States have reported increasing incidence of root rot with little or no crown or foliar symptoms in sugar beet with Rhizoctonia crown and root rot. In addition, Rhizoctonia-resistant beets have been reported wit...

  5. Induce systemic resistance in lupine against root rot diseases.

    Science.gov (United States)

    Ali, Abeer A; Ghoneem, K M; El-Metwally, M A; Abd El-Hai, K M

    2009-02-01

    Root rot caused by soil borne pathogenic fungi is the most sever disease attacks lupine plants. Isolation trials from diseased plants in some areas of Dakahlia Province (Egypt) was carried out. Rhizoctonia solani and Fusarium solani proved to be the most dominant isolates. Meanwhile, Fusarium oxysporum and Sclerotium rolfsii were less frequent. Efficacies of some plant resistance elicitors viz.: chitosan (CHI), Salicylic Acid (SA) and hydroquinone (HQ) in comparing to the fungicide Rhizolex T-50 as seed treatments showed significant reduction in the fungal growth in vitro. Chitosan at 8 g L(-1) and fungicide completely inhibited the growth of all isolated fungi, while SA at 1.4 g L(-1) and HQ at 1.2 g L(-1) inhibited the growth of Fusarium solani and F. oxysporum, respectively. The greenhouse experiments showed that S. rolfesii (No. 6) and R. solani (No. 2) followed by F. solani (No. 5) and F. oxysporum (No. 9) were the most aggressive root rot fungi. Soaking susceptible lupine seeds (Giza 1) in each one of the three selected elicitors showed a significant reduction in seedlings mortality. CHI at 8 g L(-1) was superior in increasing the percentage of healthy plants to record 72.5, 80.9, 62.7and 64.3%, when seeds were grown in soil infested with of F. solani, F. oxysporum, R. solani and S. rolfesii, respectively. These results were confirmed under field conditions in two different locations i.e., Tag El-Ezz and El-Serow Research Stations. CHI 8 g L(-1) proved to be the best elicitor after fungicide, in reducing lupine root rot disease. It showed 41 and 60% reduction in the plants mortality comparing to 56.37 and 69.13% in case of Rhizolex-T in Tag El-Ezz and El-Serow locations, respectively. The treatments were accompanied with a significant increase in lupine growth parameters, yield components and physiological aspects. Application of CHI at 8 g L(-1) or HQ at 1.2 g L(-1) was the most potent in this respect as compared to check treatment.

  6. Rhizoctonia root rot (Rhizoctoni solani K ü h n of sugar beet in province Vojvodina

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    Stojšin Vera B.

    2006-01-01

    Full Text Available Sugar beet root rot appears regularly each year, but its intensity depends on agro ecological conditions. The predominant causers of root rot in Vojvodina are fungi from Fusarium genus and species Macrophomina phaseolina. Over the last couple of years, more intense occurrence of Rhizoctonia root rot has been observed. Rhizoctonia solani, the causal agent of root rot is present in sugar beet fields. During 2000-2005, on the territory of Vojvodina, the frequency of Rhizoctonia solani in phytopathological isolations from rotted sugar beet roots was between 0,0-18,2%. The intensity of the disease depends on localities, agro ecological conditions and genotypes. Symptoms of Rhizoctonia root rot were registered at some localities in all regions of Vojvodina: Srem, Banat and Bačka. The disease appearance is above all local. It occurs in small patches, on heavy, non-structured soil and on depressed wet parts of plots. Individual diseased plants can be found during July. Brown rot appears on sugar beet roots, with dried tissue on surface, which is present on the tail as well as on the middle part and the head of root. Tissues with described symptoms are deeper regarding the healthy part of root. On vertical root section, the necrotic changes are clearly visible comparing to tissue section without symptoms. The heavily infected tissue forms fissures on roots in most cases. Besides the above-mentioned symptoms on roots, the plant wilting and leaf handle necrosis as well as leaf dying are also observed. When rot spreads to the whole root head, plants quickly die.

  7. Root rot diseases of sugarbeet (Beta vulgaris L as affected by defloliation intensity

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    Karadimos Dimitros A.

    2006-01-01

    Full Text Available The aim of this work was to study the effect of sugar beet re-growth after water stress defoliation on root rots of three cultivars (Europa, Rival Corsica, which were spring sown in Thessaly, central Greece, for two growing seasons (2003-04. At the beginning of July, sugar beets were subjected to water deficit with irrigation withholding. A month later, three defoliation levels (control - C, moderate - MD, severe - SD and irrigation were applied. Thus, sugar beets were forced to re-grow and three harvests (15, 30 and 40 days after defoliation - DAD were conducted. Rotted roots per hectare were counted and pathogens were identified. Data were analyzed as a four-factor randomized complete block design with years, defoliation levels, sampling times and cultivars as main factors. The number of rotted roots was increased with the defoliation level and was significantly higher for SD sugar beets (3748 roots ha–1. No significant differences were found between C and MD treatments (1543 and 2116 roots ha–1, respectively. Rival was the most susceptible cultivar to root rots. Sugar beets were more susceptible to rotting 15 and 40 DAD (2778 and 2998 roots ha–1. The causal agents of root rots were the fungi, Fusarium spp., Rhizopus stolonifer, Macrophomina phaseolina and Rhizoctonia solani.

  8. Factors Influencing Development of Root Rot on Ginseng Caused by Cylindrocarpon destructans.

    Science.gov (United States)

    Rahman, Mahfuzur; Punja, Zamir K

    2005-12-01

    ABSTRACT The fungus Cylindrocarpon destructans (Zins) Scholten is the cause of root rot (disappearing root rot) in many ginseng production areas in Canada. A total of 80 isolates of C. destructans were recovered from diseased roots in a survey of ginseng gardens in British Columbia from 2002-2004. Among these isolates, 49% were classified as highly virulent (causing lesions on unwounded mature roots) and 51% were weakly virulent (causing lesions only on previously wounded roots). Pectinase and polyphenoloxidase enzymes were produced in vitro by C. destructans isolates when they were grown on pectin and phenol as a substrate, respectively. However, highly virulent isolates produced significantly (P disease development, ginseng roots were grown hydroponically in Hoagland's solution. Lesions were significantly larger (P disease by a highly virulent isolate at both pHs. In artificially infested soil, 2-year-old ginseng roots were most susceptible to Cylindrocarpon root rot among all root ages tested (1 to 4 years) when evaluated using a combined scale of disease incidence and severity. Root rot severity was significantly (P Disease severity was higher at 20 degrees C compared with 15 and 25 degrees C and at -0.02 MPa soil moisture compared with -0.005 and -0.001 MPa. A significant interaction between soil moisture and temperature was observed for root rot severity.

  9. Interaction of Meloidogyne javanica and Macrophomina phaseoli in Kenaf Root Rot.

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    Tu, C C; Cheng, Y H

    1971-01-01

    Incidence and severity of root-rot caused by the fungus Macrophomina phaseoli was increased in screenhouse-grown kenaf (Hibiscus cannabinus L.) seedlings simultaneously infected by the nematode Meloidogyne javanica. In seedlings inoculated at 5, 10 and 15 days of age, root rot lesions increased 70.3, 44.1 and 21.8%, and nematode penetration increased 49.0, 36.7, and 12.3% when both fungus and nematode were present.

  10. Leuconostoc spp. Associated with Root Rot in Sugar Beet and Their Interaction with Rhizoctonia solani.

    Science.gov (United States)

    Strausbaugh, Carl A

    2016-05-01

    Rhizoctonia root and crown rot is an important disease problem in sugar beet caused by Rhizoctonia solani and also shown to be associated with Leuconostoc spp. Initial Leuconostoc studies were conducted with only a few isolates and the relationship of Leuconostoc with R. solani is poorly understood; therefore, a more thorough investigation was conducted. In total, 203 Leuconostoc isolates were collected from recently harvested sugar beet roots in southern Idaho and southeastern Oregon during 2010 and 2012: 88 and 85% Leuconostoc mesenteroides, 6 and 15% L. pseudomesenteroides, 2 and 0% L. kimchi, and 4 and 0% unrecognized Leuconostoc spp., respectively. Based on 16S ribosomal RNA sequencing, haplotype 11 (L. mesenteroides isolates) comprised 68 to 70% of the isolates in both years. In pathogenicity field studies with commercial sugar beet 'B-7', all Leuconostoc isolates caused more rot (P rot (P rot when both Leuconostoc spp. and R. solani are present in sugar beet roots.

  11. First Report of Root Rot of Cowpea Caused by Fusarium equiseti in Georgia in the United States

    Science.gov (United States)

    Root rot was observed on cowpea in Tift County, Georgia, in May of 2015. The disease occurred on approximately 10% of cowpea plants in 2 fields (2 ha). Symptoms appeared as sunken reddish brown lesions on roots and stems under the soil line, secondary roots became dark brown and rotted, and infected...

  12. Morphological and RAPD Analysis of Fusarium Species Associated with Root and Stem Rot of Dendrobium Orchid in Northern Peninsula Malaysia

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    LATIFFAH ZAKARIA

    2009-06-01

    Full Text Available A total of 29 Fusarium isolates were isolated from Dendrobium orchid showing symptoms of root and stem rots. Based on morphological characteristics, three species were identified namely, F. oxysporum, F. solani, and F. proliferatum which were recovered from root and stem rots of Dendrobium. Cluster analysis of RAPD bands clearly separated F. oxysporum, F. proliferatum, and F. solani into distinct clusters. The present studies showed that three Fusarium species were isolated from root and stem rot of Dendrobium and cluster analysis of RAPD bands was in agreement with morphological characterization of the Fusarium species from root and stem rot of Dendrobium.

  13. Survey of root rot diseases of sugar bett in Central Greece

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    Karadimos Dimitros A.

    2006-01-01

    Full Text Available An extensive survey was conducted during the summer and autumn of 2004 in sugar beet fields in the area of Larissa, Thessaly region, with plants showing symptoms of root rot diseases. The aim of the monitoring was to identify the causal agents of root rot diseases. In total, 76 sugar beet fields were surveyed and 5-10 diseased roots were examined from each field. Isolations, carried out on PDA, showed that two main fungal pathogens causing root rot were Rhizoctonia solani and Phytophthora cryptogea. The former was isolated in 46% of the fields and the latter in 38% of the fields. In addition, Rhizopus stolonifer, Fusarium spp., Scerotium rolfsii and Rhizoctonia violacea were isolated in 14%, 7%, 4% and 1% of the fields respectively. In most of the surveyed fields only one pathogen species was isolated and only in a few of them more than one fungal species was identified.

  14. Root rot symptoms in sugar beet lines caused by Fusarium oxysporum f. sp. betae

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    The soil-borne fungus Fusarium oxysporum may cause both Fusarium yellows and Fusarium root rot diseases with severe yield losses in cultivated sugar beet worldwide. These two diseases cause similar foliar symptoms but different root response and have been proposed to be due to two distinct F. oxyspo...

  15. Management of Phytophthora cinnamomi root rot disease of blueberry with gypsum and compost

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    Root rot disease of blueberry caused by Phytophthora cinnamomi is becoming more prevalent as a consequence of widespread adoption of drip irrigation. This creates higher moisture content in the root zone more conducive for the pathogen. Options for disease control under organic management are limi...

  16. A novel penicillium sp. causes rot in stored sugar beet roots in Idaho

    Science.gov (United States)

    Penicillium vulpinum along with a number of other fungi can lead to the rot of stored sugar beet roots. However, Penicillium isolates associated with necrotic lesions on roots from a recent sugar beet storage study were determined to be different from P. vulpinum and other recognized Penicillium sp...

  17. Root rot of peas in the Netherlands: fungal pathogens, inoculum potential and soil receptivity.

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    Oyarzun, P.J.

    1994-01-01

    Fungi associated to pea (Pisum sativum L.) root rot were studied. Fusarium and Oomycetes were most common. Fusarium solani f. sp. pisi, Fsp, was widely distributed and the most frequent fungus in roots of diseased crops. The pathogens Thielaviopsis basicola , Tb, and Aphanomyces euteiches, Ae, wer

  18. Phytophthora Root and Crown Rot on Apples in Bulgaria

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    Mariana Nakova

    2010-01-01

    Full Text Available Phytophthora is a genus of Oomycota responsible for some of the most serious diseases with great economic impact (Judelson and Blanco, 2005. While 54 species were found in the 20th century (Erwin and Ribeiro, 1996 another 51-54 new species have been identified(Brasier, 2008 since the year 2000. They are spread worldwide and have broad range of host plants – fruit trees, citrus, forest and park species. Phytophthora can cause serious damages in orchards and nurseries of apples, cherries, etc. In Bulgaria they have been found first on young apples and cherries (1998-1999 in Plovdiv region (Nakova, 2003. Surveys have been done for discovering disease symptoms in Plovdiv and Kjustendil regions. Isolates have been obtained from infected plant material (roots and stem bases applying baiting bioassay (green apples, variety Granny Smith and/or PARP 10 selective media. Phytophthora strains were identified based on standard morphology methods – types of colonies on PDA, CMA, V 8, type and size of sporangia, oogonia and antheridia, andoospores. Cardial temperatures for their growth were tested on CMA and PDA.For molecular studies, DNA was extracted from mycelium using the DNA extraction kit.DNA was amplified using universal primers ITS 6 and ITS 4. Amplification products concentrations were estimated by comparison with the standard DNA. Sequencing was done at the Scottish Crop Research Institute (SCRI, Dundee, Scotland. Phytophthora root and crown rot symptoms first appear in early spring. Infected trees show bud break delay, have small chlorotic leaves, and branches die all of a sudden. Later symptoms are found in August-September. Leaves of the infected trees show reddish discoloration and drop down. Both symptoms are connected with lesions (wet, necrotic in appearance at stem bases of the trees.Disease spread was 2-3% in most gardens, only in an apple orchard in Bjaga (Plovdiv region it was up to 8-10%. Morphologically, the isolates acquired from

  19. Occurrence of Root Rot and Vascular Wilt Diseases in Roselle (Hibiscus sabdariffa L.) in Upper Egypt.

    Science.gov (United States)

    Hassan, Naglaa; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-03-01

    Roselle (Hibiscus sabdariffa L.) family Malvaceae is an important crop used in food, cosmetics and pharmaceutics industries. Roselle is cultivated mainly in Upper Egypt (Qena and Aswan governorates) producing 94% of total production. Root rot disease of roselle is one of the most important diseases that attack both seedlings and adult plants causing serious losses in crop productivity and quality. The main objective of the present study is to identify and characterize pathogens associated with root rot and wilt symptoms of roselle in Qena, Upper Egypt and evaluate their pathogenicity under greenhouse and field condition. Fusarium oxysporum, Macrophomina phaseolina, Fusarium solani, Fusarium equiseti and Fusarium semitectum were isolated from the natural root rot diseases in roselle. All isolated fungi were morphologically characterized and varied in their pathogenic potentialities. They could attack roselle plants causing damping-off and root rot/wilt diseases in different pathogenicity tests. The highest pathogenicity was caused by F. oxysporum and M. phaseolina followed by F. solani. The least pathogenic fungi were F. equiseti followed by F. semitectum. It obviously noted that Baladi roselle cultivar was more susceptible to infection with all tested fungi than Sobhia 17 under greenhouse and field conditions. This is the first report of fungal pathogens causing root rot and vascular wilt in roselle in Upper Egypt.

  20. rDNA-based characterization of a new binucleate Rhizoctonia spp. causing root rot on kale in Brazil

    NARCIS (Netherlands)

    Kuramae, E.E.; Buzeto, A.L.; Nakatani, A.K.; Souza, N.L.

    2007-01-01

    In this paper we present the first report of the occurrence of a binucleate Rhizoctonia spp. causing hypocotyl and root rot in kale in Brazil. Rhizoctonia spp. were isolated from kale (Brassica oleracea var. acephala) with symptoms of hypocotyl and root rot. The isolates, characterized as binucleate

  1. rDNA-based characterization of a new binucleate Rhizoctonia spp. causing root rot on kale in Brazil

    NARCIS (Netherlands)

    Kuramae, E.E.; Buzeto, A.L.; Nakatani, A.K.; Souza, N.L.

    2007-01-01

    In this paper we present the first report of the occurrence of a binucleate Rhizoctonia spp. causing hypocotyl and root rot in kale in Brazil. Rhizoctonia spp. were isolated from kale (Brassica oleracea var. acephala) with symptoms of hypocotyl and root rot. The isolates, characterized as binucleate

  2. Root Rot of Balloon Flower (Platycodon grandiflorum) Caused by Fusarium solani and Fusarium oxysporum.

    Science.gov (United States)

    Jeon, Chi Sung; Kim, Gyoung Hee; Son, Kyeong In; Hur, Jae-Seoun; Jeon, Kwon-Seok; Yoon, Jun-Hyuck; Koh, Young Jin

    2013-12-01

    Balloon flower (Platycodon grandiflorum) is a kind of mountain herbs whose roots have restorative properties and the cultivating acreage of balloon flower has been steadily increasing in Korea. More frequent rain and high amount of rainfalls as a result of climate changes predisposed balloon flower to the outbreaks of root rot at high-density cultivation area in recent years. Root crowns were usually discolored into brown to blackish brown at first and the infected plants showed slight wilting symptom at early infection stage. Severely infected roots were entirely rotted and whole plants eventually died at late infection stage. The overall disease severities of root rot of balloon flower were quite variable according to the surveyed fields in Jeonnam, Gyeongnam and Jeju Provinces, which ranged from 0.1% to 40%. The root rot occurred more severely at the paddy or clay soils than the sandy soils and their severities were much higher at lowland than upland in the same localty. The disease increased with aging of the balloon flower. The causal fungi were identified as Fusarium solani and F. oxysporum on the basis of their mycological characteristics. The optimum temperature ranges of their mycelial growths was found to be 24°C. The pathogenic characters of F. solani and F. oxysporum treated by artificial wounding inoculation on healthy roots of balloon flower revealed that F. solani was more virulent than F. oxysporum. This study identified the causal agents of root rot of balloon flower as Fusarium solani and F. oxysporum, probably for the first time.

  3. Cylindrocarpon root rot: multi-gene analysis reveals novel species within the Ilyonectria radicicola species complex

    NARCIS (Netherlands)

    Cabral, A.; Groenewald, J.Z.; Rego, C.; Oliveira, H.; Crous, P.W.

    2012-01-01

    Ilyonectria radicicola and its Cylindrocarpon-like anamorph represent a species complex that is commonly associated with root rot disease symptoms on a range of hosts. During the course of this study, several species could be distinguished from I. radicicola sensu stricto based on morphological and

  4. Identification of markers associated with race-specific resistance to Aphanomyces root rot in alfalfa

    Science.gov (United States)

    Aphanomyces root rot, caused by Aphanomyces euteiches, is one of the most important diseases of alfalfa in the United States. Two races of the pathogen are recognized and although most cultivars are resistant to race 1, fewer have resistance to race 2, the predominant race in North America. Molecula...

  5. Efficacy of management tools for control of Pythium root rot of Douglas-fir seedlings, 2013

    Science.gov (United States)

    This study was conducted as part of the IR-4 Ornamental Horticulture program to evaluate fungicides and biopesticides for management of root, crown and stem rots of ornamental plants caused by Pythium species. Pythium species used in this study were P. vipa (isolate 09), P. dissotocum (isolate 41-08...

  6. Study of the influence of winter rye on soybean seedling and root rot diseases

    Science.gov (United States)

    Cover crops can enhance or suppress plant diseases, but little is known about the effect of cover crops on soybean diseases. In 2015, the effect of winter rye (Secale cereale L.) cover crop on soybean seedling and root rot was studied at two experimental sites, Boyd and ISUAG-USB, in Ames, IA. Both ...

  7. Rhizosphere ecology and phytoprotection in soils naturally suppressive to Thielaviopsis black root rot of tobacco.

    Science.gov (United States)

    Almario, Juliana; Muller, Daniel; Défago, Geneviève; Moënne-Loccoz, Yvan

    2014-07-01

    Soil suppressiveness to disease is an intriguing emerging property in agroecosystems, with important implications because it enables significant protection of susceptible plants from soil-borne pathogens. Unlike many soils where disease suppressiveness requires crop monoculture to establish, certain soils are naturally suppressive to disease, and this type of specific disease suppressiveness is maintained despite crop rotation. Soils naturally suppressive to Thielaviopsis basicola-mediated black root rot of tobacco and other crops occur in Morens region (Switzerland) and have been studied for over 30 years. In Morens, vermiculite-rich suppressive soils formed on morainic deposits while illite-rich conducive soils developed on sandstone, but suppressiveness is of microbial origin. Antagonistic pseudomonads play a role in black root rot suppressiveness, including Pseudomonas protegens (formerly P. fluorescens) CHA0, a major model strain for research. However, other types of rhizobacterial taxa may differ in prevalence between suppressive and conducive soils, suggesting that the microbial basis of black root rot suppressiveness could be far more complex than solely a Pseudomonas property. This first review on black root rot suppressive soils covers early findings on these soils, the significance of recent results, and compares them with other types of suppressive soils in terms of rhizosphere ecology and plant protection mechanisms.

  8. Combining fuzzy set theory and nonlinear stretching enhancement for unsupervised classification of cotton root rot

    Science.gov (United States)

    Cotton root rot is a destructive disease affecting cotton production. Accurate identification of infected areas within fields is useful for cost-effective control of the disease. The uncertainties caused by various infection stages and newly infected plants make it difficult to achieve accurate clas...

  9. Cylindrocarpon root rot: multi-gene analysis reveals novel species within the Ilyonectria radicicola species complex

    NARCIS (Netherlands)

    Cabral, A.; Groenewald, J.Z.; Rego, C.; Oliveira, H.; Crous, P.W.

    2012-01-01

    Ilyonectria radicicola and its Cylindrocarpon-like anamorph represent a species complex that is commonly associated with root rot disease symptoms on a range of hosts. During the course of this study, several species could be distinguished from I. radicicola sensu stricto based on morphological and

  10. Identification and Characterization of Partial Resistance to Fusarium root rot in the Pisum Core Collection

    Science.gov (United States)

    Fusarium solani f. sp. pisi (Fsp) is a serious seed and root rot pathogen found in both dryland and irrigated peas in the USA. Resistance to Fsp in 44 wild pea accessions from the Pisum Core Collection located in Pullman, WA, USA was characterized under greenhouse conditions. Germination rates, ro...

  11. QTL analysis for Fusarium root rot resistance in snap bean under greenhouse conditions

    Science.gov (United States)

    Fusarium root rot (FRR), caused by Fusarium solani f. sp. phaseoli (syn.F. phaseoli T. Aoki & O’Donnell, F. cuneirostrum O’Donnell & T. Aoki), is considered as one of the most economically important and widespread fungal diseases of common bean (1). Progress in breeding for FRR resistance has been h...

  12. Evaluation of pea accessions and commercial cultivars for Fusarium Root Rot resistance

    Science.gov (United States)

    Fusarium root rot caused by Fusarium solani f. sp. pisi (Fsp) can result in major yield losses in pea (Pisum sativum L.). Currently no fungicides effectively manage this disease. Previous studies evaluated the Pisum germplasm collection for resistance to Fsp, however, evaluations of commercial marke...

  13. Controlled release fungicide, soil amendments and biofumigation effects on cotton root rot suppression

    Science.gov (United States)

    The cotton root rot pathogen (Phymatotrichopsis ominora) causes major losses in cotton produced in the Southwest. Granular controlled release formulations (CRF) of the fungicide, Propiconazole, developed to be soil applied at planting were studied at 1.0 and 3.0 lb a.i./ac. applications and with tw...

  14. Mechanisms of qualitative and quantitative resistance to Aphanomyces root rot in alfalfa

    Science.gov (United States)

    Aphanomyces root rot (ARR), caused by Aphanomyces euteiches, is one of the most important diseases of alfalfa (Medicago sativa) in the United States. Two races of the pathogen are currently recognized. Most modern alfalfa cultivars have high levels of resistance to race 1 but few cultivars have resi...

  15. Irrigation affects severity of root rot caused by Phythophthora plurivora and P. cinnamomi on rhododendron

    Science.gov (United States)

    Plant pathogens in the genus Phytophthora cause root rot that decrease product quality and result in plant death and economic losses to the nursery industry. Recently, we found Phytophthora plurivora prevalent on rhododendron in nurseries in the Pacific Northwest, USA, but there is little informatio...

  16. Armillaria root rot of tea in Kenya. Characterization of the pathogen and approaches to disease management

    NARCIS (Netherlands)

    Otieno, W.

    2002-01-01

    The rare occurrence of basidiomata and rhizomorphs constrains diagnosis of Armillaria root rot and identification of Armillaria species in Africa. This has had a negative impact on taxonomic research on the genus Armillaria in the continent, where the existence of various genetic groups of the fungu

  17. Rhizoctonia root rot resistance in experimental sugar beet cultivars in Twin Falls County, ID, 2012

    Science.gov (United States)

    Rhizoctonia root rot continues to be a concerning problem in sugar beet production areas. To investigate resistance to this disease in 26 experimental sugar beet cultivars, field studies were conducted with three Rhizoctonia solani AG-2-2 IIIB strains. Based on means for the 26 cultivars, surface ...

  18. Rhizoctonia root rot resistance in commercial sugar beet cultivars in Twin Falls County, ID, 2012

    Science.gov (United States)

    Rhizoctonia root rot continues to be a concerning problem in sugar beet production areas. To investigate resistance to this disease in 26 commercial sugar beet cultivars, field studies were conducted with three Rhizoctonia solani AG-2-2 IIIB strains. Based on means for the 26 cultivars, surface ro...

  19. New record of Phytophthora root and stem rot of Lavandula angustifolia

    Directory of Open Access Journals (Sweden)

    Leszek B. Orlikowski

    2013-12-01

    Full Text Available Phytophthora cinnamomi was isolated from rotted root and stem parts of lavender as well as from soil taken from containers with diseased plants. Additionally Botrytis cinerea, Fusarium spp. and Sclerotinia sclerotiorum were often isolated from diseased tissues. P. cinnamomi colonised leaves and stem parts of 4 lavender species in laboratory trials and caused stem rot of plants in greenhouse experiments. Cardinal temperature for in vitro growth were about 7,5 and 32°C with optimum 25-27,5°C. The species colonised stem tissues at temperature ranged from 10° to 32°C.

  20. Phytophthora root and stem rot – new disease of Ilex aquifolium "Myrtifolia” in Poland

    Directory of Open Access Journals (Sweden)

    Leszek B. Orlikowski

    2014-08-01

    Full Text Available Phytophthora cinnamomi was often isolated from rotted roots and stems of English holly "Myrtifolia" together with Alternaria alternata, Cylindrocarpon destructanss, Fusarium avenaceum and other fungal species. Inoculation of leaf blades and stem parts of 4 species and 12 holly cultivars with P. cinnamomi showed the spread of rot symptoms on the most of them. On Ilex crenata tissues necrosis did not develop or spread slowly. Isolation of P. cinnamomi only from one holly cultivar in surveyed nursery indicate on transmission of the pathogen with imported young plants.

  1. Insights Into Triticum aestivum Seedling Root Rot Caused by Fusarium graminearum.

    Science.gov (United States)

    Wang, Qing; Vera Buxa, Stefanie; Furch, Alexandra; Friedt, Wolfgang; Gottwald, Sven

    2015-12-01

    Fusarium graminearum is one of the most common and potent fungal pathogens of wheat (Triticum aestivum), known for causing devastating spike infections and grain yield damage. F. graminearum is a typical soil-borne pathogen that builds up during consecutive cereal cropping. Speculation on systemic colonization of cereals by F. graminearum root infection have long existed but have not been proven. We have assessed the Fusarium root rot disease macroscopically in a diverse set of 12 wheat genotypes and microscopically in a comparative study of two genotypes with diverging responses. Here, we show a 'new' aspect of the F. graminearum life cycle, i.e., the head blight fungus uses a unique root-infection strategy with an initial stage typical for root pathogens and a later stage typical for spike infection. Root colonization negatively affects seedling development and leads to systemic plant invasion by tissue-adapted fungal strategies. Another major outcome is the identification of partial resistance to root rot. Disease severity assessments and histological examinations both demonstrated three distinct disease phases that, however, proceeded differently in resistant and susceptible genotypes. Soil-borne inoculum and root infection are considered significant components of the F. graminearum life cycle with important implications for the development of new strategies of resistance breeding and disease control.

  2. Synergistic Effects of Nanochitin on Inhibition of Tobacco Root Rot Disease.

    Science.gov (United States)

    Zhou, Yang; Jiang, Shijun; Jiao, Yongji; Wang, Hezhong

    2017-02-22

    Nanomaterials have great potential for use in various fields, due to their unique properties. In order to explore the bioactivity of nanochitin on tobacco, the effects of nanochitin suspensions on tobacco seed germination, seedling growth, and synergistic effects with fungicides were studied in indoor and field trials. Results showed that 0.004% (w/v) of nanochitin improved tobacco seed germination and shortened mean time to germination significantly; 0.005% (w/v) of nanochitin increased tobacco stem length, stem girth, leaf number and leaf area, and 0.001% (w/v) of nanochitin had synergistic effects on inhibition of tobacco root rot when mixed with metalaxyl mancozeb and thiophanate methyl fungicides. This indicates that nanochitin suspensions have a strong potential to protect tobacco from tobacco root rot diseases and reduce the use of chemical fungicides in tobacco plantations.

  3. The Use of Antioxidants to Control Root Rot and Wilt Diseases of Pepper

    Directory of Open Access Journals (Sweden)

    Montaser Fawzy ABDEL-MONAIM

    2010-06-01

    Full Text Available Ten isolates of Fusarium spp were isolated from pepper plants collected from different locations in New Valley Governorate, Egypt. Fusarium solani isolate FP2 and F. oxysporum isolate FP4 were highly pathogenic isolates but the other isolates moderate or less pathogenic to pepper plants (cv. Anaheim-M. The four antioxidant compounds (coumaric acid, citric acid, propylgalate and salicylic acid each at 100 and 200 ppm were evaluated for their in vitro and in vivo agonist to Fusarium pathogenic isolates caused root rot and wilt diseases in pepper plants. All tested antioxidant compounds reduced damping-off, root rot/wilt and area under root rot/wilt progress curve when used as seed soaking, seedling soaking, and soil drench especially at 200 ppm under greenhouse and field conditions compared with untreated plants. All chemicals increased fresh and dry weight of seedling grown in soil drenching or seed treatment with any antioxidants. At the same time, all tested chemicals significantly increase plant growth parameters i.e plant length, plant branching, and total yield per plant in case of seedling soaking or soil drench. In general, propylgalate at 200 ppm was more efficient in reducing infection with damping-off, root rot and wilt diseases as well as increasing the seedling fresh weight, dry weight, plant length, plant branching, number of pod plant-1 and pod yield plant-1. On the other hand, all tested antioxidants had less or no effect on mycelial dry weight and mycelial leaner growth. On the contrary, all chemicals much reduced spore formation in both Fusarium species at 100 or 200 ppm and the inhibitory effect of antioxidants increased with increasing their concentrations.

  4. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions

    Science.gov (United States)

    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi

    2014-01-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle. PMID:25606010

  5. Control of Root Rot and Wilt Diseases of Roselle under Field Conditions.

    Science.gov (United States)

    Hassan, Naglaa; Elsharkawy, Mohsen Mohamed; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-12-01

    Roselle (Hibiscus sabdariffa L.) is one of the most important medicinal crops in many parts of the world. In this study, the effects of microelements, antioxidants, and bioagents on Fusarium oxysporum, F. solani, and Macrophomina phaseolina, the causal pathogens of root rot and wilt diseases in roselle, were examined under field conditions. Preliminary studies were carried out in vitro in order to select the most effective members to be used in field control trials. Our results showed that microelements (copper and manganese), antioxidants (salicylic acid, ascorbic acid, and EDTA), a fungicide (Dithane M45) and biological control agents (Trichoderma harzianum and Bacillus subtilis) were significantly reduced the linear growth of the causal pathogens. Additionally, application of the previous microelements, antioxidants, a fungicide and biological control agents significantly reduced disease incidence of root rot and wilt diseases under field conditions. Copper, salicylic acid, and T. harzianum showed the best results in this respect. In conclusion, microelements, antioxidants, and biocontrol agents could be used as alternative strategies to fungicides for controlling root rot and wilt diseases in roselle.

  6. Diaporthaceae associated with root and crown rot of maize

    NARCIS (Netherlands)

    Lamprecht, S.C.; Crous, P.W.; Groenewald, J.Z.; Tewoldemedhin, Y.T.; Marasas, W.F.O.

    2011-01-01

    Several isolates of coelomycetous fungi with pigmented conidia were consistently isolated from diseased roots of Zea mays in irrigated plots monitored in the KwaZulu-Natal Province of South Africa. Based on their morphology, these isolates could be identified as representative of Stenocarpella macro

  7. The Genetic Structure of Phellinus noxius and Dissemination Pattern of Brown Root Rot Disease in Taiwan.

    Science.gov (United States)

    Chung, Chia-Lin; Huang, Shun-Yuan; Huang, Yu-Ching; Tzean, Shean-Shong; Ann, Pao-Jen; Tsai, Jyh-Nong; Yang, Chin-Cheng; Lee, Hsin-Han; Huang, Tzu-Wei; Huang, Hsin-Yu; Chang, Tun-Tschu; Lee, Hui-Lin; Liou, Ruey-Fen

    2015-01-01

    Since the 1990s, brown root rot caused by Phellinus noxius (Corner) Cunningham has become a major tree disease in Taiwan. This fungal pathogen can infect more than 200 hardwood and softwood tree species, causing gradual to fast decline of the trees. For effective control, we must determine how the pathogen is disseminated and how the new infection center of brown root rot is established. We performed Illumina sequencing and de novo assembly of a single basidiospore isolate Daxi42 and obtained a draft genome of ~40 Mb. By comparing the 12,217 simple sequence repeat (SSR) regions in Daxi42 with the low-coverage Illumina sequencing data for four additional P. noxius isolates, we identified 154 SSR regions with potential polymorphisms. A set of 13 polymorphic SSR markers were then developed and used to analyze 329 P. noxius isolates collected from 73 tree species from urban/agricultural areas in 14 cities/counties all around Taiwan from 1989 to 2012. The results revealed a high proportion (~98%) of distinct multilocus genotypes (MLGs) and that none of the 329 isolates were genome-wide homozygous, which supports a possible predominant outcrossing reproductive mode in P. noxius. The diverse MLGs exist as discrete patches, so brown root rot was most likely caused by multiple clones rather than a single predominant strain. The isolates collected from diseased trees near each other tend to have similar genotype(s), which indicates that P. noxius may spread to adjacent trees via root-to-root contact. Analyses based on Bayesian clustering, FST statistics, analysis of molecular variance, and isolation by distance all suggest a low degree of population differentiation and little to no barrier to gene flow throughout the P. noxius population in Taiwan. We discuss the involvement of basidiospore dispersal in disease dissemination.

  8. The Genetic Structure of Phellinus noxius and Dissemination Pattern of Brown Root Rot Disease in Taiwan.

    Directory of Open Access Journals (Sweden)

    Chia-Lin Chung

    Full Text Available Since the 1990s, brown root rot caused by Phellinus noxius (Corner Cunningham has become a major tree disease in Taiwan. This fungal pathogen can infect more than 200 hardwood and softwood tree species, causing gradual to fast decline of the trees. For effective control, we must determine how the pathogen is disseminated and how the new infection center of brown root rot is established. We performed Illumina sequencing and de novo assembly of a single basidiospore isolate Daxi42 and obtained a draft genome of ~40 Mb. By comparing the 12,217 simple sequence repeat (SSR regions in Daxi42 with the low-coverage Illumina sequencing data for four additional P. noxius isolates, we identified 154 SSR regions with potential polymorphisms. A set of 13 polymorphic SSR markers were then developed and used to analyze 329 P. noxius isolates collected from 73 tree species from urban/agricultural areas in 14 cities/counties all around Taiwan from 1989 to 2012. The results revealed a high proportion (~98% of distinct multilocus genotypes (MLGs and that none of the 329 isolates were genome-wide homozygous, which supports a possible predominant outcrossing reproductive mode in P. noxius. The diverse MLGs exist as discrete patches, so brown root rot was most likely caused by multiple clones rather than a single predominant strain. The isolates collected from diseased trees near each other tend to have similar genotype(s, which indicates that P. noxius may spread to adjacent trees via root-to-root contact. Analyses based on Bayesian clustering, FST statistics, analysis of molecular variance, and isolation by distance all suggest a low degree of population differentiation and little to no barrier to gene flow throughout the P. noxius population in Taiwan. We discuss the involvement of basidiospore dispersal in disease dissemination.

  9. The Growth of Root Rot Disease on Pepper Seed Applied by Trichoderma Harzianum Inoculum

    Directory of Open Access Journals (Sweden)

    S. Sofian

    2013-06-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 Root rot disease on pepper caused by Phytophthora capsici is one of the most important diseases on pepper. The using of antagonistic fungus of Trichoderma harzianum as a biological control agent of the pathogen is one of the important alternatives in controlling P. capsici without causing negative effects on the environment. The objectives of the research were to study about the ability of T. harzianum inoculum application in inhibiting the development of root-rot disease, influenced the growth of pepper seed, to studythe effective length time application of T. harzianum inoculum in inhibiting the development of root rot disease, and increased the growth of pepper seedlings. This research was arranged in a completely randomized design, with five treatments of length time application of T. harzianum inoculum i.e. control treatment without applicationtime of T. harzianum inoculum (K, application time of T. harzianum inoculum for 0 week (S0, application time of T. harzianum inoculum for 1 week (S1, application time of T. harzianum inoculum for two weeks (S2, application time of T. harzianum inoculum for three weeks (S3, and application time of T. harzianum inoculum for 4 weeks (S4 before planting. Each treatment was repeated15 times. The observed parameterswere disease percentage, the inhibition of antagonistic fungus, disease infection rate, plant height, number of leaves, wet and dry weight of plant, stem and leaves on pepper seed, and P. capsici population density. The result showed that application time of T. harzianum inoculumfor 4 weeks (S4 before planting is the most effective time in inhibiting the development of root rot disease than the other treatment sand also had significant effect on increasing the growth of pepper seed. The antagonism test showed that T. harzianum could inhibit P. capsiciin vitro. This result proves that application time of T. harzianum inoculums

  10. Basal Root Rot, a new Disease of Teak (Tectona grandis in Malaysia caused by Phellinus noxius

    Directory of Open Access Journals (Sweden)

    Mohd Farid, A.

    2005-01-01

    Full Text Available Basal root rot of teak was first reported from Sabak Bernam, Selangor making this the first report of the disease on teak in Peninsular Malaysia. The fungus found associated with the disease was Phellinus noxious. The disease aggressively killed its host irrespective of the host health status. Bark depression at the root collar which was visible from a distance was the characteristic symptom and the main indicator in identifying the disease in the plantation since above ground symptoms of the canopy could not be differentiated from crowns of healthy trees. However, although above ground symptoms were not easily discernible, the disease was already advanced and the trees mostly beyond treatment; 3.4 % of the trees in the plantation were affected and the disease occurred both on solitary trees and in patches. Below ground, infected trees had rotted root systems, mainly below and around the collar region with brown discolored wood and irregular golden-brown honeycomb-like pockets of fungal hyphae in the wood. Pathogenicity tests showed that the fungus produced symptoms similar to those observed in the plantation and killed two year-old teak plants. The disease killed all the inoculated hosts within three months, irrespective of wounded or unwounded treatments.

  11. Selection of potential antagonists against asparagus crown and root rot caused by Fusarium spp.

    Science.gov (United States)

    Rubio-Pérez, E; Molinero-Ruiz, M L; Melero-Vara, J M; Basallote-Ureba, M J

    2008-01-01

    Crown and root rot is one of the most important diseases of asparagus crop worldwide. Fusarium oxysporum f.sp. asparagi and F. proliferatum are the two species more frequently associated to this complex and their prevalence depends on the production area. The control of the disease on asparagus crop is difficult to achieve because its perennial condition and the long survival of the pathogen in the soil as chlamydospores or as mycelium in infected plant debris. Furthermore, Fusarium spp. are easily disseminated with asparagus propagation materials. Thus, control measures should aim at obtaining seedlings protection for longer than achieved with conventional pre-planting chemical treatments. The effectiveness of fungal antagonists on the control of diseases caused by soil borne fungi has been reported. The potential of Trichoderma spp. as a biological control agent against diseases caused by Fusarium spp. in tomato and asparagus has been studied . It has been suggested that microorganisms isolated from the root or rhizosphere of a specific crop may be better adapted to that crop and may provide better disease control than organisms originally isolated from other plant species. The objective of this work was the evaluation of the potential of fungal isolates from symptomless asparagus plants as biocontrol agents of Fusarium crown and root rot.

  12. Etiology and epidemiology of Pythium root rot in hydroponic crops: current knowledge and perspectives

    Directory of Open Access Journals (Sweden)

    John Clifford Sutton

    2006-09-01

    Full Text Available The etiology and epidemiology of Pythium root rot in hydroponically-grown crops are reviewed with emphasis on knowledge and concepts considered important for managing the disease in commercial greenhouses. Pythium root rot continually threatens the productivity of numerous kinds of crops in hydroponic systems around the world including cucumber, tomato, sweet pepper, spinach, lettuce, nasturtium, arugula, rose, and chrysanthemum. Principal causal agents include Pythium aphanidermatum, Pythium dissotocum, members of Pythium group F, and Pythium ultimum var. ultimum. Perspectives are given of sources of initial inoculum of Pythium spp. in hydroponic systems, of infection and colonization of roots by the pathogens, symptom development and inoculum production in host roots, and inoculum dispersal in nutrient solutions. Recent findings that a specific elicitor produced by P. aphanidermatum may trigger necrosis (browning of the roots and the transition from biotrophic to necrotrophic infection are considered. Effects on root rot epidemics of host factors (disease susceptibility, phenological growth stage, root exudates and phenolic substances, the root environment (rooting media, concentrations of dissolved oxygen and phenolic substances in the nutrient solution, microbial communities and temperature and human interferences (cropping practices and control measures are reviewed. Recent findings on predisposition of roots to Pythium attack by environmental stress factors are highlighted. The commonly minor impact on epidemics of measures to disinfest nutrient solution as it recirculates outside the crop is contrasted with the impact of treatments that suppress Pythium in the roots and root zone of the crop. New discoveries that infection of roots by P. aphanidermatum markedly slows the increase in leaf area and whole-plant carbon gain without significant effect on the efficiency of photosynthesis per unit area of leaf are noted. The platform of

  13. The effect of mangroves amendments to soil on root rot and root knot of potato (Solanum tuberosum L.

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    Marium Tariq

    2012-12-01

    Full Text Available Leaves, stem and pneumatophore of Avicennia marina and leaves and stem of Rhizophora mucronata were used as the organic amendments at 0.1, 1 and 5% concentrations in the control of root rot fungi like (Fusarium spp., Rhizoctonia solani and Macrophomina phasoelina and root knot nematode Meloidogyne javanica on potato. In pot experiments, germination of seeds, shoot length, shoot weight, root length, root weight and number of knots were significantly increased when plant parts like leaves, stem and pneumatophore of A. marina and R. mucronata were used at 1 and 5% concentrations. There was a complete suppression in infection of R. solani and M. phaseolina when A. marina and R. mucronata were used at 5% concentration on potato. Maximum inhibition of knots of M. javanica was observed when powder made from mangrove plant parts was used at 1 and 5% concentrations. Powder from all plant parts, like leaves, stem and pneumatophore, was effective in suppression of root infecting fungi and root knot nematode.

  14. SSR-based detection of genetic variability in the charcoal root rot pathogen Macrophomina phaseolina.

    Science.gov (United States)

    Jana, Tarakanta; Sharma, Tilak R; Singh, Nagendra K

    2005-01-01

    Macrophomina phaseolina, the causal agent of charcoal root or collar rot, is an important plant pathogen especially in soybean and cotton. Single primers of simple sequence repeats (SSR) or microsatellite markers have been used for the characterization of genetic variability of different populations of M. phaseolina obtained from soybean and cotton grown in India and the USA. Genetic similarity between isolates was calculated, and cluster analysis was used to generate a dendrogram showing relationships between isolates collected from the two hosts. Forty isolates could be clustered into three major groups corresponding to their hosts and geographical region. The wide distribution of microsatellites in M. phaseolina genome was assessed by agarose gel electrophoresis of the PCR products generated by direct amplification of inter SSR regions DNA. This is the first report of the use of microsatellite markers to characterize the charcoal root rot pathogen. The SSR fingerprints (0.25-3.5 kb) generated using DNA from different populations of M. phaseolina of two hosts indicated that these repeats are interspersed within the genome of this pathogen. The variability found within closely related isolates of M. phaseolina indicated that such microsatellites are useful in population studies and represents a step towards identification of potential isolate diagnostic markers specific to soybean and cotton.

  15. A combination of biocontrol agents improves the management of dry root rot (Macrophomina phaseolina in greengram

    Directory of Open Access Journals (Sweden)

    R. Thilagavathi

    2007-08-01

    Full Text Available The biocontrol agents Trichoderma viride (strains Tv1 and Tv13, Pseudomonas fluorescens (Pf1 and Py15 and Bacillus subtilis (Bs16 were tested individually and in combination for their effectiveness against root rot of greengram caused by Macrophomina phaseolina. As regards the compatibility of the biocontrol agents with each other, T. viride strains were not compatible with B. subtilis (Bs16, but P. fluorescens strains were compatible with B. subtilis and T. viride. Of the biocontrol agents tested in vitro against M. phaseolina, combinations of P. fluorescens+T. viride (Pf1+Tv1, Pf1+Tv13 and Py15+Tv1 inhibited mycelial growth of the pathogen and they also promoted the growth of the greengram seedlings. A combination of Pf1+Tv1 was most effective in reducing root rot incidence under glass-house and field conditions as compared with other single or combined treatments or the untreated control. The activity of the defense-related enzymes peroxidase, polyphenol oxidase and phenyl alanine ammonia lyase was significantly greater in greengram plants treated with a talc based formulation containing Pf1+Tv1 followed by Pf1+Tv13 and Py15+Tv1, than in plants receiving other treatments or the untreated control. Moreover, a combination of Pf1+Tv1 followed by Pf1+Tv13 and Py15+Tv1 significantly increased yield under glass house and field conditions.

  16. Efficacy of Chaetomium Species as Biological Control Agents against Phytophthora nicotianae Root Rot in Citrus.

    Science.gov (United States)

    Hung, Phung Manh; Wattanachai, Pongnak; Kasem, Soytong; Poeaim, Supattra

    2015-09-01

    Thailand is one of the largest citrus producers in Southeast Asia. Pathogenic infection by Phytophthora, however, has become one of major impediments to production. This study identified a pathogenic oomycete isolated from rotted roots of pomelo (Citrus maxima) in Thailand as Phytophthora nicotianae by the internal transcribed spacer ribosomal DNA sequence analysis. Then, we examined the in vitro and in vivo effects of Chaetomium globosum, Chaetomium lucknowense, Chaetomium cupreum and their crude extracts as biological control agents in controlling this P. nicotianae strain. Represent as antagonists in biculture test, the tested Chaetomium species inhibited mycelial growth by 50~56% and parasitized the hyphae, resulting in degradation of P. nicotianae mycelia after 30 days. The crude extracts of these Chaetomium species exhibited antifungal activities against mycelial growth of P. nicotianae, with effective doses of 2.6~101.4 µg/mL. Under greenhouse conditions, application of spores and methanol extracts of these Chaetomium species to pomelo seedlings inoculated with P. nicotianae reduced root rot by 66~71% and increased plant weight by 72~85% compared to that in the control. The method of application of antagonistic spores to control the disease was simple and economical, and it may thus be applicable for large-scale, highly effective biological control of this pathogen.

  17. The preventive Control of White Root Rot Disease in Small Holder Rubber Plantation Using Botanical, Biological and Chemical Agents

    Directory of Open Access Journals (Sweden)

    Joko Prasetyo

    2014-03-01

    Full Text Available The preventive control of white root rot disease in small holder plantation using botanical, biological, and chemical agents. A field and laboratory experiment were conducted from June 2008 to December 2009 in Panumangan, Tulang Bawang - Lampung. The  field experiment was intended to evaluate the effect of  botanical plants (Alpinia galanga, Sansiviera auranthii, and Marantha arundinacea, biological agents (organic matter and Trichoderma spp., and chemical agents (lime and natural sulphur on the incidence of white root rot disease and population of some soil microbes. The laboratory experiment was conducted  to observe the mechanism of botanical agents  in controlling white root rot disease. In the field experiment, the treatments were applied  in the experimental plot with cassava plant infection as the indicator. The variables  examined were the incidence of  white root rot and population of soil microbes. In the laboratory experiment, culture of R. microporus was grown in PDA containing root exudate of the antagonistic plant (botanical agent. The variable examined was colony diameter of R. microporus growing in the PDA plates. The results of the  field experiment  showed that planting of the botanical agents, and application of Trichoderma spp., as well as natural sulphur, decreased the incidence of white root rot disease. The effectiveness of M. arundinacea and Trichoderma spp. was comparable to natural  sulphur. The laboratory experiment showed only root exudate of  A. galanga and  S. auranthii that were significantly inhibit the growth of R. microporus.

  18. Adaptive expression of host cell wall degrading enzymes in fungal disease: an example from Fusarium root rot of medicinal Coleus.

    Science.gov (United States)

    Bhattacharya, A

    2013-12-15

    Quantity of extracellular proteins and activities two cell wall degrading enzymes pectinase and cellulase were determined in the culture filtrate of Fusarium solani, the causal organism of root rot of Coleus forskohlii. Substitution of carbon source in the medium with either pectin or carboxymethyl cellulose led to the increased production of extracellular proteins by the fungus. Pectinase and cellulase activity in the culture filtrate was detected only when the growth medium contained substituted carbon source in the form of pectin and CMC, respectively. Pectinase activity was highest after 5 days incubation and then decreased gradually with time but cellulase activity showed a steady time dependent increase. In vitro virulence study showed the requirement of both the enzymes for complete expression of rot symptoms on Coleus plants. Thus the present study established the adaptive, substrate dependent expression of the two enzymes by the fungus and also their involvement in the root rot disease of Coleus forskohlii.

  19. Wilt, crown, and root rot of common rose mallow (Hibiscus moscheutos) caused by a novel Fusarium sp.

    Science.gov (United States)

    A new crown and root rot disease of landscape plantings of the malvaceous ornamental common rose mallow (Hibiscus moscheutos) was first detected in Washington State in 2012. The main objectives of this study were to identify the causal agent using multilocus molecular phylogenetics and to complete K...

  20. Gene-for-gene relationships between strawberry and the causal agent of red stele root rot, Phytophthora fragariae var. fragariae.

    NARCIS (Netherlands)

    Weg, van de W.E.

    1997-01-01

    Red stele (red core) root rot is the major soil-borne disease of strawberries (Fragaria spp.) in many areas with cool, moist soil conditions. It is caused by the soil-borne fungus Phytophthora fragariae var. fragariae. Red stele is a quarantine disease in Europe with a zero tolerance for commercial

  1. Conduciveness of different soilless growing media to Pythium root and crown rot of cucumber under near-commercial conditions

    NARCIS (Netherlands)

    Gaag, van der D.J.; Wever, G.

    2005-01-01

    Substrates made from rockwool, coir dust, pumice and perlite were compared for conduciveness to Pythium root and crown rot in cucumber under near-commercial conditions. Rockwool slabs of 7 cm height were more conducive to the Pythium disease than coir dust slabs, pumice or perlite under these condit

  2. Effect of cultural practices and fungicide treatments on the severity of Phytophthora root rot of blueberries grown in Mississippi

    Science.gov (United States)

    Phytophthora root rot is an important disease of blueberries, especially those grown in areas with poor drainage. Reliable cultural and chemical management strategies are needed for control of this disease. Two studies were conducted to evaluate the effects of cultural practices and fungicide treat...

  3. Occurrence of the root-rot pathogen, Fusarium commune, in forest nurseries of the midwestern and western United States

    Science.gov (United States)

    Mee-Sook Kim; Jane E. Stewart; R. Kasten Dumroese; Ned B. Klopfenstein

    2012-01-01

    Fusarium commune can cause damping-off and root rot of conifer seedlings in forest nurseries, and this pathogen has been previously reported from Oregon, Idaho, and Washington, USA. We collected Fusarium isolates from additional nurseries in the midwestern and western USA to more fully determine occurrence of this pathogen. We used DNA sequences of the mitochondrial...

  4. Isolates of Rhizoctonia solani can produce both web blight and root rot symptoms in common bean (Phaseolus vulgaris L.)

    Science.gov (United States)

    Rhizoctonia solani Kühn (Rs) is an important pathogen in the tropics, causing web blight (WB), and a widespread soil-borne root rot (RR) pathogen of common bean (Phaseolus vulgaris L.) worldwide. This pathogen is a species complex classified into 14 anastomosis groups (AG). Some AGs have been report...

  5. The prevalence of different strains of Rhizoctonia solani associated with Rhizoctonia crown and root rot symptoms in Ontario sugarbeet fields

    Science.gov (United States)

    Rhizoctonia crown and root rot (RCRR) [Rhizoctonia solani Kühn] is an important disease of sugarbeets in southwestern Ontario, Canada. A survey of commercial sugarbeet fields was completed in 2010 and 2011 to determine the range of R. solani anastomosis groups (AGs) and inter-specific groups (ISGs) ...

  6. ROOT ROT OF CHILLI INCITED BY Sclerotium rolfsii Sacc. AND ITS MANAGEMENT- A REVIEW

    Directory of Open Access Journals (Sweden)

    V.Madhuri

    2014-02-01

    Full Text Available Chilli (Capsicum annum L. belongs to the family solanaceae is mainly cultivated for its vegetable green fruits and dry chilli as the spice. It is believed to be originated from South America. It is a rich source of Vitamin C, A and B. Chilli is valued for pungency which is imparted by an alkaloid, Capsaicin and the red pigments (Capsanthin, Capsorubin and Capxanthin. Chillies are widely used as spice, condiment, culinary, supplement, medicine, vegetable and are ornamental plants too. It is an important food flavouring ingredientfor flavouring many vegetarian and non-vegetarian food products. In view of its multifarious uses, the demand for chillies has been on the increase world over. In India it is an important cash crop, which is grown for the domestic market and for export. In India, chillies are grown in almost all states of the country and the major growing states in terms of production are Andhra Pradesh, Karnataka, Orissa, Maharashtra, West Bengal, Rajasthan and Tamil Nadu. There are several varieties of chilli cultivated in India. The most popular among these are, Sannam, LC334, Byadagi, Wonderhot, Jwala etc. The crop suffers from many diseases like damping off, anthracnose or fruit rot or dieback, wilt, leaf spots and powdery mildew. Among the fungal diseases, root rot of chilli caused by Sclerotium rolfsii has attained the economic importance. In recent years, this disease is causing the economic losses in chillies crop (Kalmesh and Gurjar 2001.

  7. A Simple Method for Assessing Severity of Common Root Rot on Barley

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    Mohammad Imad Eddin Arabi

    2013-12-01

    Full Text Available Common root rot caused by Cochliobolus sativus is a serious disease of barley. A simple and reliable method for assessing this disease would enhance our capacity in identifying resistance sources and developing resistant barley cultivars. In searching for such a method, a conidial suspension of C. sativus was dropped onto sterilized elongated subcrown internodes and incubated in sandwich filter paper using polyethylene transparent envelopes. Initial disease symptoms were easily detected after 48h of inoculation. Highly significant correlation coefficients were found in each experiment (A, B and C between sandwich filter paper and seedling assays, indicating that this testing procedure was reliable. The method presented facilitates a rapid pre-selection under uniform conditions which is of importance from a breeder’s point of view.

  8. Unconventional alternatives for control of tomato root rot caused by Rhizoctonia solani under greenhouse conditions

    Directory of Open Access Journals (Sweden)

    Hamza Amany

    2016-07-01

    Full Text Available This study was done to assess the antifungal effect of some biocontrol agents effective microorganisms (EMs1, Pseudomonas fluorescens, and Bacillus pumilus, titanium dioxide (TiO2 nanoparticles, black cumin and wheat germ oils as well as the recommended fungicide (flutolanil against root rot of tomato. Moreover, gas chromatography-mass spectrometry (GC-MS examination was completed to identify the bioactive compounds in plant oils (dark cumin and wheat germ. Also the impact of these medicines on some biochemical and growth parameters of tomato was examined. Flutolanil was the best treatment followed by dark cumin, TiO2, EMs1, Pseudomonas fluorescens, Bacillus pumilus and wheat germ oil, individually in both test seasons. The outcomes demonstrated a marked increase in each biochemical character (chlorophyll substance, peroxidase and polyphenoloxidase and plant development (height and fresh and dry weight under all the tried treatments in comparison to the controls.

  9. Primary structure of the histone 2B gene in the white root rot fungus, Rosellinia necatrix.

    Science.gov (United States)

    Aimi, Tadanori; Taguchi, Hiroyuki; Morinaga, Tsutomu

    2002-12-01

    The nucleotide sequence of the histone 2B (H2B) gene in the white root rot fungus, Rosellinia necatrix, was determined. The gene has two introns in the coding region at positions conserved in the Neurospora crassa and Aspergillus nidulans H2B genes, but the third intron present in the H2B gene from N. crassa and A. nidulans is absent in the R. necatrix H2B gene. The amino acid sequence of the coding region of the R. necatrix gene resembled that of N. crassa and A. nidulans. Therefore, the third intron in the H2B gene of N. crassa and A. nidulans may have been inserted into the present position after species diversification.

  10. FIRST REPORT OF Phytophthora nicotianae CAUSING ROOT ROT OF SOURSOP IN NORTHEASTERN BRAZIL

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    JAQUELINE FIGUEREDO DE OLIVEIRA COSTA

    Full Text Available ABSTRACT In 2013, soursop trees showing symptoms of root rot were observed in a field in Maceió, state of Alagoas, Brazil. It was isolated Phytophthora sp. which pathogenicity was confirmed in the host seedlings. Morphological and physiological characteristics in carrot-agar modified medium were consistent with Phytophthora nicotianae description. The PCR sequences products obtained with ITS1/ITS4 primers were compared to sequences of ribosomal DNA of Phytophthora species from the GenBank database observing high identity with other P. nicotianae isolates. A phylogenetic tree was performed to compare the isolate with other sequences of P. nicotianae, which clustering has been verified with 99% of bootstrap, confirming the morphophysiological studies. This is the first report of this pathogen on annonaceous plants in the Northeastern Brazil.

  11. Incorporation of plant materials in the control of root pathogens in muskmelon

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    Andréa Mirne de Macêdo Dantas

    2013-12-01

    Full Text Available The effect of plant materials[Sunn Hemp (Crotalaria juncea, Castor Bean (Ricinus communis L., Cassava (Manihot esculenta Crantz and Neem (Azadirachta indica] and the times of incorporation of these materials in regards to the incidence of root rot in melon was evaluated in Ceará state, Brazil. The experiment was conducted in a commercial area with a history of root pathogens in cucurbitaceae. The randomized block design was used, in a 5 x 3 factorial arrangement with four repetitions. The treatments consisted of a combination of four plant materials (sunn hemp, castor beans, cassava and neem and a control with no soil incorporation of plant material and three times of incorporation (28, 21, and 14 days before the transplanting of the seedlings. Lower incidence of root rot was observed in practically all of the treatments where materials were incorporated at different times, with variation between the materials, corresponding with the time of incorporation, in relation to the soil without plant material. The pathogens isolated from the symptomatic muskmelon plants were Fusarium solani, Macrophomina phaseolina, Monosporascus cannonballus and Rhizoctonia solani, F. solani being encountered most frequently.

  12. Resistance in tomato and wild relatives to crown and root rot caused by Phytophthora capsici.

    Science.gov (United States)

    Quesada-Ocampo, L M; Hausbeck, M K

    2010-06-01

    Phytophthora capsici causes root, crown, and fruit rot of tomato, a major vegetable crop grown worldwide. The objective of this study was to screen tomato cultivars and wild relatives of tomato for resistance to P. capsici. Four P. capsici isolates were individually used to inoculate 6-week-old seedlings (1 g of P. capsici-infested millet seed per 10 g of soilless medium) of 42 tomato cultivars and wild relatives of tomato in a greenhouse. Plants were evaluated daily for wilting and death. All P. capsici isolates tested caused disease in seedlings but some isolates were more pathogenic than others. A wild relative of cultivated tomato, Solanum habrochaites accession LA407, was resistant to all P. capsici isolates tested. Moderate resistance to all isolates was identified in the host genotypes Ha7998, Fla7600, Jolly Elf, and Talladega. P. capsici was frequently recovered from root and crown tissue of symptomatic inoculated seedlings but not from leaf tissue or asymptomatic or control plants. The phenotype of the recovered isolate matched the phenotype of the inoculum. Pathogen presence was confirmed in resistant and moderately resistant tomato genotypes by species-specific polymerase chain reaction of DNA from infected crown and root tissue. Amplified fragment length polymorphisms of tomato genotypes showed a lack of correlation between genetic clusters and susceptibility to P. capsici, indicating that resistance is distributed in several tomato lineages. The results of this study create a baseline for future development of tomato cultivars resistant to P. capsici.

  13. GmPGIP3 enhanced resistance to both take-all and common root rot diseases in transgenic wheat.

    Science.gov (United States)

    Wang, Aiyun; Wei, Xuening; Rong, Wei; Dang, Liang; Du, Li-Pu; Qi, Lin; Xu, Hui-Jun; Shao, Yanjun; Zhang, Zengyan

    2015-05-01

    Take-all (caused by the fungal pathogen Gaeumannomyces graminis var. tritici, Ggt) and common root rot (caused by Bipolaris sorokiniana) are devastating root diseases of wheat (Triticum aestivum L.). Development of resistant wheat cultivars has been a challenge since no resistant wheat accession is available. GmPGIP3, one member of polygalacturonase-inhibiting protein (PGIP) family in soybean (Glycine max), exhibited inhibition activity against fungal endopolygalacturonases (PGs) in vitro. In this study, the GmPGIP3 transgenic wheat plants were generated and used to assess the effectiveness of GmPGIP3 in protecting wheat from the infection of Ggt and B. sorokiniana. Four independent transgenic lines were identified by genomic PCR, Southern blot, and reverse transcription PCR (RT-PCR). The introduced GmPGIP3 was integrated into the genomes of these transgenic lines and could be expressed. The expressing GmPGIP3 protein in these transgenic wheat lines could inhibit the PGs produced by Ggt and B. sorokiniana. The disease response assessments postinoculation showed that the GmPGIP3-expressing transgenic wheat lines displayed significantly enhanced resistance to both take-all and common root rot diseases caused by the infection of Ggt and B. sorokiniana. These data suggested that GmPGIP3 is an attractive gene resource in improving resistance to both take-all and common root rot diseases in wheat.

  14. Endophytic fungi harbored in Panax notoginseng: diversity and potential as biological control agents against host plant pathogens of root-rot disease

    Directory of Open Access Journals (Sweden)

    You-Kun Zheng

    2017-07-01

    Conclusion: Our results suggested that P. notoginseng harbors diversified endophytic fungi that would provide a basis for the identification of new bioactive compounds, and for effective biocontrol of notoginseng root rot.

  15. Prevention and Control of Gentiana macrophylla Pall Root Rot Disease%秦艽根腐病的防治

    Institute of Scientific and Technical Information of China (English)

    程远辉; 侯志江; 徐中志

    2014-01-01

    The root rot is a major disease affecting yield of Gentiana macrophyl a pal , reducing yield or even causing total crop failure. This research introduced the occurrence characteristics and various control techniques of root rot of Gentiana macrophyl a pal , in order to provide references for farmers.%根腐病是影响秦艽产量的最主要病害,发病后会造成秦艽严重减产甚至绝收。笔者总结了秦艽根腐病的发生特点及各种防治技术,以期为广大药农提供指导。

  16. Wide variation in virulence and genetic diversity of binucleate Rhizoctonia isolates associated with root rot of strawberry in Western Australia.

    Directory of Open Access Journals (Sweden)

    Xiangling Fang

    Full Text Available Strawberry (Fragaria×ananassa is one of the most important berry crops in the world. Root rot of strawberry caused by Rhizoctonia spp. is a serious threat to commercial strawberry production worldwide. However, there is no information on the genetic diversity and phylogenetic status of Rhizoctonia spp. associated with root rot of strawberry in Australia. To address this, a total of 96 Rhizoctonia spp. isolates recovered from diseased strawberry plants in Western Australia were characterized for their nuclear condition, virulence, genetic diversity and phylogenetic status. All the isolates were found to be binucleate Rhizoctonia (BNR. Sixty-five of the 96 BNR isolates were pathogenic on strawberry, but with wide variation in virulence, with 25 isolates having high virulence. Sequence analysis of the internal transcribed spacers of the ribosomal DNA separated the 65 pathogenic BNR isolates into six distinct clades. The sequence analysis also separated reference BNR isolates from strawberry or other crops across the world into clades that correspond to their respective anastomosis group (AG. Some of the pathogenic BNR isolates from this study were embedded in the clades for AG-A, AG-K and AG-I, while other isolates formed clades that were sister to the clades specific for AG-G, AG-B, AG-I and AG-C. There was no significant association between genetic diversity and virulence of these BNR isolates. This study demonstrates that pathogenic BNR isolates associated with root rot of strawberry in Western Australia have wide genetic diversity, and highlights new genetic groups not previously found to be associated with root rot of strawberry in the world (e.g., AG-B or in Australia (e.g., AG-G. The wide variation in virulence and genetic diversity identified in this study will be of high value for strawberry breeding programs in selecting, developing and deploying new cultivars with resistance to these multi-genetic groups of BNR.

  17. Wide variation in virulence and genetic diversity of binucleate Rhizoctonia isolates associated with root rot of strawberry in Western Australia.

    Science.gov (United States)

    Fang, Xiangling; Finnegan, Patrick M; Barbetti, Martin J

    2013-01-01

    Strawberry (Fragaria×ananassa) is one of the most important berry crops in the world. Root rot of strawberry caused by Rhizoctonia spp. is a serious threat to commercial strawberry production worldwide. However, there is no information on the genetic diversity and phylogenetic status of Rhizoctonia spp. associated with root rot of strawberry in Australia. To address this, a total of 96 Rhizoctonia spp. isolates recovered from diseased strawberry plants in Western Australia were characterized for their nuclear condition, virulence, genetic diversity and phylogenetic status. All the isolates were found to be binucleate Rhizoctonia (BNR). Sixty-five of the 96 BNR isolates were pathogenic on strawberry, but with wide variation in virulence, with 25 isolates having high virulence. Sequence analysis of the internal transcribed spacers of the ribosomal DNA separated the 65 pathogenic BNR isolates into six distinct clades. The sequence analysis also separated reference BNR isolates from strawberry or other crops across the world into clades that correspond to their respective anastomosis group (AG). Some of the pathogenic BNR isolates from this study were embedded in the clades for AG-A, AG-K and AG-I, while other isolates formed clades that were sister to the clades specific for AG-G, AG-B, AG-I and AG-C. There was no significant association between genetic diversity and virulence of these BNR isolates. This study demonstrates that pathogenic BNR isolates associated with root rot of strawberry in Western Australia have wide genetic diversity, and highlights new genetic groups not previously found to be associated with root rot of strawberry in the world (e.g., AG-B) or in Australia (e.g., AG-G). The wide variation in virulence and genetic diversity identified in this study will be of high value for strawberry breeding programs in selecting, developing and deploying new cultivars with resistance to these multi-genetic groups of BNR.

  18. Research Progress of Root Rot Disease in Barley%大麦根腐病研究进展

    Institute of Scientific and Technical Information of China (English)

    兰国防; 张凤英; 包海柱; 武海明; 刘志萍

    2014-01-01

    As one of the most serious worldwide disease affecting the yield and quality of barley,Root Rot Disease was widely distribu-ted in the Daxinganling mountain area and the Yangtze River basin in China. Root Rot Disease in Barely is the fungal disease caused by Biplaris sorokiniana and its pathogenic bacteria can be parasitized and also can be saprophyticed with strong adaptability. This paper mainly reviewed the cause of root rot disease,its biological characteristics,host range,disease symptoms,identification of the disea-ses,genetics of resistance,and measures on how to control this disease as well as the outlook of the research prospects in root rot dis-ease in barley.%大麦根腐病是严重危害大麦产量和品质的世界性病害之一,在我国的大兴安岭西麓和长江流域分布广泛。大麦根腐病是由根腐离蠕孢菌( Biplaris sorokiniana)引起的真菌性病害,其致病菌可寄生也可腐生,适应性极强。本文主要从大麦根腐病的病原及其生物学特性、寄主范围、病害症状、病害鉴定、抗性遗传和防治方法等方面进行了综述,并展望了大麦根腐病的研究前景。

  19. Fusarium paranaense sp. nov., a member of the Fusarium solani species complex causes root rot on soybean in Brazil.

    Science.gov (United States)

    Costa, Sarah S; Matos, Kedma S; Tessmann, Dauri J; Seixas, Claudine D S; Pfenning, Ludwig H

    2016-01-01

    Isolates of Fusarium obtained from soybean plants showing symptoms of root rot collected in subtropical southern and tropical central Brazil were characterized based on phylogenetic analyses, sexual crossing, morphology, and pathogenicity tests. A novel species within the Fusarium solani species complex (FSSC) causing soybean root rot is formally described herein as Fusarium paranaense. This species can be distinguished from the other soybean root rot pathogens in the FSSC, which are commonly associated with soybean sudden death syndrome (SDS) based on analyses of the combined DNA sequences of translation elongation factor 1-α and the second largest subunit of RNA polymerase II and on interspecies mating compatibility. Bayesian and maximum parsimony phylogenetic analyses showed that isolates of F. paranaense formed a distinct group in clade 3 of the FSSC in contrast to the pathogens currently known to cause SDS, which are in clade 2. Female fertile tester strains were developed that can be used for the identification of this new species in the FSSC based on sexual crosses. All isolates were heterothallic and belonged to a distinct mating population. Fusarium tucumaniae, a known SDS pathogen, was found in the subtropical southern region of the country.

  20. Microbiota Characterization of Compost Using Omics Approaches Opens New Perspectives for Phytophthora Root Rot Control.

    Science.gov (United States)

    Blaya, Josefa; Marhuenda, Frutos C; Pascual, Jose A; Ros, Margarita

    2016-01-01

    Phytophthora root rot caused by Phytophthora nicotianae is an economically important disease in pepper crops. The use of suppressive composts is a low environmental impact method for its control. Although attempts have been made to reveal the relationship between microbiota and compost suppressiveness, little is known about the microorganisms associated with disease suppression. Here, an Ion Torrent platform was used to assess the microbial composition of composts made of different agro-industrial waste and with different levels of suppressiveness against P. nicotianae. Both bacterial and fungal populations responded differently depending on the chemical heterogeneity of materials used during the composting process. High proportions (67-75%) of vineyard pruning waste were used in the most suppressive composts, COM-A and COM-B. This material may have promoted the presence of higher relative abundance of Ascomycota as well as higher microbial activity, which have proved to be essential for controlling the disease. Although no unique fungi or bacteria have been detected in neither suppressive nor conducive composts, relatively high abundance of Fusarium and Zopfiella were found in compost COM-B and COM-A, respectively. To the best of our knowledge, this is the first work that studies compost metabolome. Surprisingly, composts and peat clustered together in principal component analysis of the metabolic data according to their levels of suppressiveness achieved. This study demonstrated the need for combining the information provided by different techniques, including metagenomics and metametabolomics, to better understand the ability of compost to control plant diseases.

  1. Short Rotations in Forest Plantations Accelerate Virulence Evolution in Root-Rot Pathogenic Fungi

    Directory of Open Access Journals (Sweden)

    Jean-Paul Soularue

    2017-06-01

    Full Text Available As disease outbreaks in forest plantations are causing concern worldwide, a clear understanding of the influence of silvicultural practices on the development of epidemics is still lacking. Importantly, silvicultural practices are likely to simultaneously affect epidemiological and evolutionary dynamics of pathogen populations. We propose a genetically explicit and individual-based model of virulence evolution in a root-rot pathogenic fungus spreading across forest landscapes, taking the Armillaria ostoyae–Pinus pinaster pathosystem as reference. We used the model to study the effects of rotation length on the evolution of virulence and the propagation of the fungus within a forest landscape composed of even-aged stands regularly altered by clear-cutting and thinning operations. The life cycle of the fungus modeled combines asexual and sexual reproduction modes, and also includes parasitic and saprotrophic phases. Moreover, the tree susceptibility to the pathogen is primarily determined by the age of the stand. Our simulations indicated that the shortest rotation length accelerated both the evolution of virulence and the development of the epidemics, whatever the genetic variability in the initial fungal population and the asexuality rate of the fungal species

  2. Zinc Induced Enzymatic Defense Mechanisms in Rhizoctonia Root Rot Infected Clusterbean Seedlings

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    Neha Wadhwa

    2014-01-01

    Full Text Available This investigation was planned to determine the effect of different concentrations of zinc (Zn on biochemical constituents of clusterbean, which play an important role in disease resistance mechanisms. Clusterbean seedlings were grown with 0, 10, or 20 mg Zn kg−1 soil treatments in earthen pots filled with 700 g inoculated soil. Soil was inoculated by pretreatment with 250 mg (wet weight of Rhizoctonia inoculums per pot. A similar set was maintained in uninoculated soil. Root rot incidence decreased to 41 and 27 per cent with 10 and 20 mg Zn kg−1 soil treatments, respectively, as compared to 68 percent at control. Antioxidative enzyme activity (polyphenol oxidase, peroxidase, phenylalanine ammonia lyase, and tyrosine ammonia lyase increased in inoculated seedlings and was increased further by 20 mg Zn kg−1 soil treatment. Antioxidative enzymes play an important role against fungal invasion, as peroxidase is involved in the formation of barrier via lignifications at the site of pathogen penetration. PAL and TAL play a key role in phenylpropanoid metabolism and could perform defense-related functions. Zn acts as a cofactor for these enzymes, so it can be concluded that Zn may be used as a soil-nutritive agent to increase resistance in plants against fungal diseases.

  3. Postharvest salicylic acid treatment reduces storage rots in water-stressed but no unstressed sugarbeet roots

    Science.gov (United States)

    Exogenous application of salicylic acid (SA) reduces storage rots in a number of postharvest crops. SA’s ability to protect sugarbeet (Beta vulgaris L.) taproots from common storage rot pathogens, however, is unknown. To determine the potential of SA to reduce storage losses caused by three common...

  4. Temperature, moisture, and fungicide effects in managing Rhizoctonia root and crown rot of sugar beet.

    Science.gov (United States)

    Bolton, Melvin D; Panella, Lee; Campbell, Larry; Khan, Mohamed F R

    2010-07-01

    Rhizoctonia solani AG-2-2 is the causal agent of Rhizoctonia root and crown rot in sugar beet; however, recent increases in disease incidence and severity were grounds to reevaluate this pathosystem. To assess the capacity at which other anastomosis groups (AGs) are able to infect sugar beet, 15 AGs and intraspecific groups (ISGs) were tested for pathogenicity on resistant ('FC708 CMS') and susceptible ('Monohikari') seedlings and 10-week-old plants. Several AGs and ISGs were pathogenic on seedlings regardless of host resistance but only AG-2-2 IIIB and AG-2-2 IV caused significant disease on 10-week-old plants. Because fungicides need to be applied prior to infection for effective disease control, temperature and moisture parameters were assessed to identify potential thresholds that limit infection. Root and leaf disease indices were used to evaluate disease progression of AG-2-2 IIIB- and AG-2-2 IV-inoculated plants in controlled climate conditions of 7 to 22 growing degree days (GDDs) per day. Root disease ratings were positively correlated with increasing temperature of both ISGs, with maximum disease symptoms occurring at 22 GDDs/day. No disease symptoms were evident from either ISG at 10 GDDs/day but disease symptoms did occur in plants grown in growth chambers set to 11 GDDs/day. Using growth chambers adjusted to 22 GDDs/day, disease was evaluated at 25, 50, 75, and 100% moisture-holding capacity (MHC). Disease symptoms for each ISG were highest in soils with 75 and 100% MHC but disease still occurred at 25% MHC. Isolates were tested for their ability to cause disease at 1, 4, and 8 cm from the plant hypocotyl. Only AG-2-2 IIIB was able to cause disease symptoms at 8 cm during the evaluation period. In all experiments, isolates of AG-2-2 IIIB were found to be more aggressive than AG-2-2 IV. Using environmental parameters that we identified as the most conducive to disease development, azoxystrobin, prothioconazole, pyraclostrobin, difenoconazole

  5. 油梨根腐病发病规律及防治技术%Occurrence regularity of Avocado Root Rot and Its Control Techniques

    Institute of Scientific and Technical Information of China (English)

    劳有德; 陈川

    2016-01-01

    油梨根腐病是油梨根部重要病害,近年来逐渐增多,严重时可造成油梨整株死亡,已成为油梨产业发展的重要病害。目前广西已发现有4种油梨根腐病,是较难防治的土传病害。重点介绍4种油梨根腐病的特点、发生、病因、症状等,从农业、物理、生物、化学防治方面介绍油梨根腐病的防治技术。%Avocado root rot is one of the most important root diseases on avocado, the disease is increasing in recent years. It can cause the death of the whole plant of avocado when this disease becomes seriously. The avocado root rot disease has become an important disease in avocado industry. Nowadays, there are four kinds of avocado root rot diseases are found in GuangXi Province. It is more difficult to control these soil borne diseases. This paper introduces the traits, causes, symptoms and occurrence of avocado root rot disease. And then, the control techniques for avocado root rot in agricultural, physical, biological and chemical control field and so on are introduced.

  6. Conjunctively screening of biocontrol agents (BCAs) against fusarium root rot and fusarium head blight caused by Fusarium graminearum.

    Science.gov (United States)

    Wang, Lu-Yao; Xie, Yue-Shen; Cui, Yuan-Yu; Xu, Jianjun; He, Wei; Chen, Huai-Gu; Guo, Jian-Hua

    2015-08-01

    Fusarium root-rot and fusarium head blight are plant diseases caused by Fusarium sp. in different growth periods of wheat, bring heavy losses to crop production in China. This research is aiming to screen biocontrol agents conjunctively for controlling these two diseases at the same time, as well as evaluate our previous BCAs (Biological Control Agents) screening strategies in more complex situation, considering biocontrol is well concerned as an environmental-friendly plant disease controlling method. Totally 966 bacterial isolates were screened from different parts of wheat tissues, of which potential biocontrol values were detected according to their abilities in antagonism inhibition and secreting extracellular hydrolytic enzyme. Biocontrol tests against fusarium root rot and fusarium head blight were carried out on 37 bacterial isolates with potential biocontrol capacity after pre-selection through ARDRA- and BOX-PCR analysis on strains with high assessment points. We acquired 10 BCAs with obvious biocontrol efficacy (more than 40%) in greenhouse and field tests. Pseudomonas fluorescens LY1-8 performed well in both two tests (biocontrol efficacy: 44.62% and 58.31%), respectively. Overall, correlation coefficient is 0.720 between assessment values of 37 tested BCA strains and their biocontrol efficacy in trails against fusarium root rot; correlation coefficient is 0.806 between their assessment values and biocontrol efficacy in trails against fusarium head blight. We acquired 10 well-performed potential BCAs, especially P. fluorescens LY1-8 displayed good biocontrol capacity against two different diseases on wheat. Biocontrol efficacies results in both greenhouse and field tests showed high positive correlation with assessment values (0.720 and 0.806), suggesting that the BCAs screening and assessing strategy previously developed in our lab is also adaptable for conjunctively screening BCAs for controlling both root and shoot diseases on wheat caused by same

  7. Heterobasidion annosum root rot in Picea abies: Variability in aggressiveness and resistance

    Energy Technology Data Exchange (ETDEWEB)

    Swedjemark, G.

    1995-12-31

    In greenhouse experiments 3-4 year-old plants of Picea abies and Pinus sylvestris were inoculated with the root rot fungus Heterobasidion annosum. The growth rates of 25 S and 14 P isolates of the fungus were measured in the sapwood of about 25 rametes each of 98 Norway spruce clones and in 150 seedlings each of Norway spruce and Scots pine. Correlations were determined between fungal sapwood growth and a variety of variables, i.e. the physical stage, growth rhythm, size and condition of the cuttings, provenance and the growth capacity of the clones estimated in field tests. Genetic parameters such as phenotypic and genotypic variance, genotypic coefficient of variance and broad sense heritability were calculated. H. annosum infection incidence was close to 100 % for inoculated Norway spruce clones, and the mortality rate was about 1 %. Fungal growth in sapwood differed significantly among clones and among fungal isolates. The genotypic correlation coefficient was large (30 %) and broad sense heritability was 0.35. This suggests that good selection progress can be achieved in breeding programs. The physical stage (bud-flush, vegetative and post bud-set stage) of the clones contributed significantly to the total variation in fungal growth. The population structure of H. annosum was studied in two 25-year-old, first generation stands of Norway spruce. The stands had been thinned one and seven years earlier, respectively. All stumps and remaining trees were sampled for H. annosum isolates. The isolates were tested with somatic incompatibility to detect single genets and the distribution of genets in the stand was determined. About 70 % of the 7-year-old thinning stumps were colonized by H, annosum, and 50 % of these stumps were colonized by more than one fungal genet. Sixty-three percent of the remaining trees were infected with H. annosum but among them there was only one genet per tree. 104 refs, 12 figs

  8. Effect of corn steep liquor on lettuce root rot (Fusarium oxysporum f.sp. lactucae) in hydroponic cultures.

    Science.gov (United States)

    Chinta, Yufita D; Kano, Kazuki; Widiastuti, Ani; Fukahori, Masaru; Kawasaki, Shizuka; Eguchi, Yumi; Misu, Hideyuki; Odani, Hiromitsu; Zhou, Songying; Narisawa, Kazuhiko; Fujiwara, Kazuki; Shinohara, Makoto; Sato, Tatsuo

    2014-08-01

    Recent reports indicate that organic fertilisers have a suppressive effect on the pathogens of plants grown under hydroponic systems. Furthermore, microorganisms exhibiting antagonistic activity to diseases have been observed in organic hydroponic systems. This study evaluated the effect of corn steep liquor (CSL) on controlling lettuce root rot disease [Fusarium oxysporum f.sp. lactucae (FOL)] in a hydroponic system. The effect of CSL and Otsuka A (a chemical fertiliser) on the inhibition of FOL in terms of mycelial growth inhibition was tested in vivo. Addition of CSL suppressed FOL infection rates. CSL inhibited FOL infection by 26.3-42.5% from 2 days after starting incubation. In comparison, Otsuka A inhibited FOL growth by 5.5-19.4%. In addition, four of 10 bacteria isolated from the nutrient media containing CSL exhibited inhibition zones preventing FOL mycelial growth. We found that CSL suppressed FOL in lettuce via its antifungal and biostimulatory effects. We suggest that activation of beneficial microorganisms present in CSL may be used to decrease lettuce root rot disease and contribute to lettuce root growth. © 2014 Society of Chemical Industry.

  9. Effect of Potassium on Ultrastructure of Maize Stalk Pith and Young Root and Their Relation to Stalk Rot Resistance

    Institute of Scientific and Technical Information of China (English)

    LI Wen-juan; HE Ping; JIN Ji-yun

    2010-01-01

    To study the mechanism of potassium(K)application on improvement of maize resistance to stalk rot at cellular level,scanning electron microscope and transmission electron microscope were used to observe the effect of K on the ultrastructure of maize stalk pith tissue and young root tip cell influenced by K and pathogen.In K deficient treatment,parenchyma cells of stalk pith had abnormal structure,and the cell wall between upper and lower adjacent cell was damaged,resulting in the loss of connections between vascular cells and insufficient supporting capacity.However,an improved K nutrition helped to keep a quite tight arrangement of root cell with thick cell wall,and prevent the invasion of pathogen effectively.Moreover,K treated root cell had abundant golgi apparatus,which could excrete large amount of secretions to degrade mycelium.Papillary and highly electronic intensity dot were accumulated at the invading point to prevent the development of the mycelium.Improved K nutrition could increase the resistant ability of maize plant to stalk rot,through keeping cell structure stability,preventing the expansion of intracellular space to reduce the chances of pathogen invasions,and through reinforcing cell wall and formation of intercellular and intracellular material to restrict further development of pathogen in host cell.

  10. Root interactions in a maize/soybean intercropping system control soybean soil-borne disease, red crown rot.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available BACKGROUND: Within-field multiple crop species intercropping is well documented and used for disease control, but the underlying mechanisms are still unclear. As roots are the primary organ for perceiving signals in the soil from neighboring plants, root behavior may play an important role in soil-borne disease control. PRINCIPAL FINDINGS: In two years of field experiments, maize/soybean intercropping suppressed the occurrence of soybean red crown rot, a severe soil-borne disease caused by Cylindrocladium parasiticum (C. parasiticum. The suppressive effects decreased with increasing distance between intercropped plants under both low P and high P supply, suggesting that root interactions play a significant role independent of nutrient status. Further detailed quantitative studies revealed that the diversity and intensity of root interactions altered the expression of important soybean PR genes, as well as, the activity of corresponding enzymes in both P treatments. Furthermore, 5 phenolic acids were detected in root exudates of maize/soybean intercropped plants. Among these phenolic acids, cinnamic acid was released in significantly greater concentrations when intercropped maize with soybean compared to either crop grown in monoculture, and this spike in cinnamic acid was found dramatically constrain C. parasiticum growth in vitro. CONCLUSIONS: To the best of our knowledge, this study is the first report to demonstrate that intercropping with maize can promote resistance in soybean to red crown rot in a root-dependent manner. This supports the point that intercropping may be an efficient ecological strategy to control soil-borne plant disease and should be incorporated in sustainable agricultural management practices.

  11. PATHOGENICITY TESTS AND EVALUATION OF EFFICACY OF FUNGICIDES AGAINST RHIZOCTONIA BATATICOLA, THE CAUSAL AGENT OF DRY ROOT ROT OF CHICKPEA

    Directory of Open Access Journals (Sweden)

    G Amrutha Veena

    2014-03-01

    Full Text Available The pathogen was identified based on its mycelial and sclerotial characters and pathogenicity test was proved by soil inoculation method. Efficacy of two non systemic fungicides (copper oxychloride and captan, two systemic fungicides (hexaconazole and tebuconazole and one antifungal antibiotic validamycin each at different concentrations were tested against Rhizoctonia bataticola, incitant of dry root rot of chickpea under in vitro conditions. The fungicides copper oxychloride, captan, hexaconazole and tebuconazole were found to be highly effective (100% in inhibiting the mycelial growth of the highly virulent pathogen at all the concentrations tested.

  12. Isolation screening and characterisation of local beneficial rhizobacteria based upon their ability to suppress the growth of Fusarium oxysporum f. sp. radicis-lycopersici and tomato foot and root rot

    Science.gov (United States)

    Tomato crown and root rot or tomato foot and root rot (TFRR) is caused by the phytopathogenic fungus Fusarium oxysporum f. sp. radicis-lycopersici (Forl). The disease occurs in both greenhouse and outdoor tomato cultivations and cannot be treated efficiently with the existing fungicides. We conducte...

  13. Ganoderma species, including new taxa associated with root rot of the iconic Jacaranda mimosifolia in Pretoria, South Africa.

    Science.gov (United States)

    Coetzee, Martin P A; Marincowitz, Seonju; Muthelo, Vuledzani G; Wingfield, Michael J

    2015-06-01

    Jacaranda mimosifolia trees have been progressively dying due to Ganoderma root and butt rot disease in Pretoria (the "City of Jacarandas") for many years. Ganoderma austroafricanum was described from these trees previously but this was based on a single collection. This study treats a substantially expanded collection of isolates of Ganoderma made from all dying trees where basidiomes were present in a Pretoria suburb. DNA sequences were obtained from the ITS and LSU region for the isolates and compared against sequences on GenBank. Phylogenetic analyses were used to compare sequences with those for other Ganoderma species. Based on sequence comparisons and morphological characters, two new Ganoderma species were discovered and these are described here as G. enigmaticum and G. destructans spp. nov. Interestingly, the previously described G. austroafricanum was not found, G. enigmaticum was found on only one Ceratonia siliqua tree and G. destructans was found on all other trees sampled. The latter species appears to be the primary cause of root rot of J. mimosifolia in the area sampled.

  14. Relative Efficacy of On-Farm Weeds as Soil-Amendement for Managing Dry Root Rot of Clusterbean in an Arid Environment

    Directory of Open Access Journals (Sweden)

    R. Mawar

    2006-12-01

    Full Text Available The effectiveness of certain on-farm weeds as soil amendments was ascertained against Macrophomina phaseolina, a soil-borne pathogen causing dry root rot of crops grown under rainfed conditions in arid regions. Population changes in M. phaseolina were determined in soils amended separately with residues (1%, w:w of Aerva persica, Celosia argentea, Corchorus depressus, Euphorbia hirta, Heliotropium subulatum and Polycarpaea corymbosa, for a period of 90 days. Significant reductions by 90.4–100% in the population of M. phaseolina were achieved with all the weed residues except P. corymbosa. Celosia and Euphorbia residues completely eradicated viable propagules of M. phaseolina. A strong increase (44–61% in the population of antagonistic actinomycetes was also found in soil amended with Corchorus and Euphorbia. In field tests, soil amended (50 g m2 with Euphorbia, Aerva and Celosia residues significantly reduced dry root rot incidence on clusterbean and also reduced M. phaseolina propagules in the soil. However, dry root rot incidence in Polycarpaea-amended soil (5.8–24.6% was not significantly different from that in non-amended soil (4.3–25.3% in both years of the experiment. P. corymbosa also increased the number of propagules of M. phaseolina in the soil. The results demonstrate that dry root rot of rainfed-cultivated annual crops in arid land can be managed with certain weeds as a soil amendment.

  15. Efficacy of seed treatments in reducing seed and root rot of peas in the presence of metalaxyl-resistant Pythium, 2007

    Science.gov (United States)

    Five organic seed treatments and eighteen commercial seed treatments were evaluated in a commercial pea field (sandy loam soil) in Paterson, WA to manage seed and root rot of processed peas. The soil from the field site had a mean of 89 total Pythium colonies and 27 metalaxyl-resistant Pythium colo...

  16. Influência do agrotêxtil sobre a densidade populacional de Monosporascus cannonballus em solo cultivado com melancia (Citrullus lanatus Influence of the row cover on the population density of Monosporascus cannonballus in soil cultivated with watermelon (Citrullus lanatus

    Directory of Open Access Journals (Sweden)

    Erika Valente de Medeiros

    2008-06-01

    Full Text Available O fungo Monosporascus cannonballus é um importante patógeno radicular que ocasiona a síndrome denominada colapso em cucurbitáceas. No presente trabalho, objetivou-se, avaliar os efeitos da cobertura de planta com agrotêxtil branco de 15 g m-2, sobre a densidade populacional de M. cannonballus, em solo cultivado com melancia [Citrullus lanatus (Thumb. Matsu & Nakai]. O delineamento experimental utilizado foi o de blocos casualizados em esquema de parcelas subdivididas, com três repetições. As parcelas foram constituídas por utilização ou não do agrotêxtil e as subparcelas pelas épocas de coleta de solo (0, 12, 24, 36, 48 dias após o transplantio. As variáveis analisadas foram densidade de ascósporos, temperatura do solo e do ar. Não houve influência da utilização da cobertura de agrotêxtil perante a densidade de ascósporos de M. cannonballus, no solo cultivado com melancia, mesmo que tenha proporcionado redução nas temperaturas médias do ar e do solo, sendo uma alternativa eficaz de manejo, na produção da melancia Mickylee.The fungus M. cannonballus is an important root pathogen that causes collapse in cucurbitaceas. The present work had as objective to evaluate the effect of the row cover with white polypropylene of 15 g m-2 on the population density of M.cannonballus in soil cultivated with watermelon [Citrullus lanatus (Thumb. Matsu & Nakai]. The experimental design was of randomized blocks using parcels subdivided scheme with three replications. The parcels consisted of use or not row cover and subparcelas through the time of soil collected (0, 12, 24, 36, 48 days after the transplanting. The variables evaluates were ascospores density, soil temperature and air temperature. There was not influence of the characteristics gotten for the row cover before the ascospores density of M. cannonballus, in the soils cultivated with watermelon and proportioning reduction of soil temperature means and air temperature means

  17. Rapid and sensitive diagnoses of dry root rot pathogen of chickpea (Rhizoctonia bataticola (Taub.) Butler) using loop-mediated isothermal amplification assay.

    Science.gov (United States)

    Ghosh, Raju; Tarafdar, Avijit; Sharma, Mamta

    2017-02-20

    Dry root rot (DRR) caused by the fungus Rhizoctonia bataticola (Taub.) Butler, is an emerging disease in chickpea. The disease is often mistaken with other root rots like Fusarium wilt, collar rot and black root rot in chickpea. Therefore, its timely and specific detection is important. Current detection protocols are either based on mycological methods or on protocols involving DNA amplification by polymerase chain reaction (PCR). Here we report the rapid and specific detection of R. bataticola using loop-mediated isothermal amplification (LAMP) assay targeting fungal specific 5.8S rDNA sequence for visual detection of R. bataticola. The reaction was optimized at 63 °C for 75 min using minimum 10 fg of DNA. After adding SYBR Green I in LAMP products, the amplification was found to be highly specific in all the 94 isolates of R. bataticola collected from diverse geographical regions as well as DRR infected plants and sick soil. No reaction was found in other pathogenic fungi infecting chickpea (Fusarium oxysporum f. sp. ciceris, Rhizoctonia solani, Sclerotium rolfsii and Fusarium solani) and pigeonpea (Fusarium udum and Phytophthora cajani). The standardised LAMP assay with its simplicity, rapidity and specificity is very useful for the visual detection of this emerging disease in chickpea.

  18. The effect of temperature and rainfall on participation of the pathogens causing root and stem rot in spring barley (Hordeum vulgare L.

    Directory of Open Access Journals (Sweden)

    Barbara Łacicowa

    2013-12-01

    Full Text Available Field experiments conducted in the years 1990-1995 were localized at the Plaiit Cultivation Station, Ulhówek to repeat the cultivation of spring barley cultivars Roland and Lot. In conditions of monoculture, Bipolaris sorokiniana and Fusarium culmorum were of the foremost importance in causing root and stem rot. The proportion of infected plants did not increase with time. Depending on the period of vegetation and the cultivar, the percentage of seedlings with necrosis symptoms ranged from 6% to 53,5% and that of stem base rot from 14% to 59%. In the case of both cultivars. root and stem rot was especially intensive in the third successive season of vegetation, i, e,. in 1992. That season was characterized by warm and wet weather conditions. favourable for the infection of seedlings by B.sorokiniane during the period of six weeks after the sowing of grain. Bipolaris sorokiniana always had the greatest proportion in the infction of spring barley but not in the seasons distinguished by hot and dry weather conditions. On the other hand, during dry and hot weather conditions the only or the dominating fungus obtained from the infcted stem base after the heading of spring barley was F. culmorum. In conditions of monoculture, favourable for root and stem rot of spring barley, the temperature and rainfalls clearly distinguished the proportion of B. sorokiniana and F. culmorum in plant infection.

  19. Endophytic Bacteria Improve Plant Growth, Symbiotic Performance of Chickpea (Cicer arietinum L. and Induce Suppression of Root Rot Caused by Fusarium solani under Salt Stress

    Directory of Open Access Journals (Sweden)

    Dilfuza Egamberdieva

    2017-09-01

    Full Text Available Salinity causes disturbance in symbiotic performance of plants, and increases susceptibility of plants to soil-borne pathogens. Endophytic bacteria are an essential determinant of cross-tolerance to biotic and abiotic stresses in plants. The aim of this study was to isolate non–rhizobial endophytic bacteria from the root nodules of chickpea (Cicer arietinum L., and to assess their ability to improve plant growth and symbiotic performance, and to control root rot in chickpea under saline soil conditions. A total of 40 bacterial isolates from internal root tissues of chickpea grown in salinated soil were isolated. Four bacterial isolates, namely Bacillus cereus NUU1, Achromobacter xylosoxidans NUU2, Bacillus thuringiensis NUU3, and Bacillus subtilis NUU4 colonizing root tissue demonstrated plant beneficial traits and/or antagonistic activity against F. solani and thus were characterized in more detail. The strain B. subtilis NUU4 proved significant plant growth promotion capabilities, improved symbiotic performance of host plant with rhizobia, and promoted yield under saline soil as compared to untreated control plants under field conditions. A combined inoculation of chickpea with M. ciceri IC53 and B. subtilis NUU4 decreased H2O2 concentrations and increased proline contents compared to the un-inoculated plants indicating an alleviation of adverse effects of salt stress. Furthermore, the bacterial isolate was capable to reduce the infection rate of root rot in chickpea caused by F. solani. This is the first report of F. solani causing root rot of chickpea in a salinated soil of Uzbekistan. Our findings demonstrated that the endophytic B. subtilis strain NUU4 provides high potentials as a stimulator for plant growth and as biological control agent of chickpea root rot under saline soil conditions. These multiple relationships could provide promising practical approaches to increase the productivity of legumes under salt stress.

  20. Soil amendment with Aerva javanica (Burm. F. Juss. ex Schult. in the control of root rot fungi of cowpea [Vigna unguiculata (L. Walp.] and mung bean [Vigna radiata (L.

    Directory of Open Access Journals (Sweden)

    Naheed Ikram

    2012-10-01

    Full Text Available Root rot fungi cause severe losses of crop plants, so the present work was carried out to determine the effect of Aerva javanica parts powder on root infecting fungi of mung bean (Vigna radiata (L. and cowpea (Vigna unguiculata (L. Walp.. A. javanica parts (stem, leaves and flower were used as soil amendments at 0.1, 1 and 5% to check the effectiveness on growth parameters. All the plant parts showed a significant reduction in root rot fungi like Fusarium spp., Rhizoctonia solani Kuhn, and Macrophomina phaseolina (Tassi Goid. It was noted that germination percentage, fresh weight, leaf area and number of nodules were significantly higher and the inhibitory effect on root rot fungi increased when the soil was amended with A. javanica leaves at 1%. Thus, among all the treatments, A. javanica leaves at 1% were found to be the most effective against root rot fungi.

  1. SELEÇÃO DE GENÓTIPOS DE CUCURBITÁCEAS RESISTENTES A Monosporascus cannonballus E COMPATIBILIDADE DE PORTA-ENXERTOS

    Directory of Open Access Journals (Sweden)

    ANDRÉA CELINA FERREIRA DEMARTELAERE

    2015-01-01

    Full Text Available The Monosporascus Cannonballus is the main agent of decline roots. However, grafting is be-ing tested to overcome this disease. From this perspective, the current research, aimed to screen resistant root-stocks and evaluate the compatibility of grafting watermelon Crimson Sweet. The experiments were conducted in a greenhouse and Laboratory of Plant Pathology-II, UFERSA Mossoró, RN. In the first, 12 genotypes were used: watermelon (TPR- 02978 e TPR- 04329; melon (TPR- 05851 e TPR- 08689 e pumpkin (TPR- 06827, PES- 07, PEC- 01, PEM- 06, PED- 02, PEK- 05, Shintoza e Fito, sown in pots with soil naturally infected by M. cannonballus. After 60 days, the roots were evaluated (DR and (IGD and (IA. In the second, Crimson Sweet was used as graft and PEC-01, PES-07, PEK-05 and Shintoza as rootstocks. The seventeenth day, were evaluated (% PEG, (AB2, (AC, (L, (NF, (DC, (AP, (MSPA e (MSR. The experimental design was ran-domized, using the Scott-Knott and Tukey tests SAEG® 9.1. There were lower notes the (DR: TPR-02978, TPR-06827, TPR-08689, PES-07, PEC-01, PED-02, PEK-05 e Shintoza. The (IGD: TPR-02978, TPR-08689, TPR-06827, PES-07, PEC-01, PEM-06, PED-02, PEK-05, Shintoza e Fitó. And (IA: PES-07, PEC-01 and PEK-05. The PEC-01 had the highest (% PEG. And the highest rates of MSPA and the MSR were obtained in PEC-01 and Shintoza. The TPR- 02978, TPR- 04329, TPR- 05851, TPR- 08689, TPR- 06827, PEM- 06, PED- 02, Shintoza and Fito showed susceptibility. As for PEK-05, PES-07 and PEC-01, they were resistant to M. cannonballus and the latter presented to the graft compatibility Crimson Sweet.

  2. Isolation, characterization, and formulation of antagonistic bacteria for the management of seedlings damping-off and root rot disease of cucumber.

    Science.gov (United States)

    Khabbaz, Salah Eddin; Abbasi, Pervaiz A

    2014-01-01

    Antagonistic bacteria are common soil inhabitants with potential to be developed into biofungicides for the management of seedling damping-off, root rot, and other soil-borne diseases of various crops. In this study, antagonistic bacteria were isolated from a commercial potato field and screened for their growth inhibition of fungal and oomycete pathogens in laboratory tests. The biocontrol potential of the 3 most effective antagonistic bacteria from the in vitro tests was evaluated against seedling damping-off and root rot of cucumber caused by Pythium ultimum. Based on phenotypic characteristics, biochemical tests, and sequence analysis of 16S-23S rDNA gene, the 3 antagonistic bacteria were identified as Pseudomonas fluorescens (isolate 9A-14), Pseudomonas sp. (isolate 8D-45), and Bacillus subtilis (isolate 8B-1). All 3 bacteria promoted plant growth and suppressed Pythium damping-off and root rot of cucumber seedlings in growth-room assays. Both pre- and post-planting application of these bacteria to an infested peat mix significantly increased plant fresh masses by 113%-184% and percentage of healthy seedlings by 100%-290%, and decreased damping-off and root rot severity by 27%-50%. The peat and talc formulations of these antagonistic bacteria applied as seed or amendment treatments to the infested peat mix effectively controlled Pythium damping-off and root rot of cucumber seedlings and enhanced plant growth. The survival of all 3 antagonistic bacteria in peat and talc formulations decreased over time at room temperature, but the populations remained above 10(8) CFU/g during the 180-day storage period. The peat formulation of a mixture of 3 bacteria was the best seed treatment, significantly increasing the plant fresh masses by 245% as compared with the Pythium control, and by 61.4% as compared with the noninfested control. This study suggests that the indigenous bacteria from agricultural soils can be developed and formulated as biofungicides for minimizing

  3. INFLUENCE OF NPK AND LIME APLICATION ON ERVA-MATE GROWTH, ROOT-ROT SEVERITY AND SOIL FUNGI POPULATION1

    Directory of Open Access Journals (Sweden)

    Igor Poletto

    2011-09-01

    Full Text Available The present work evaluated the influence of the application of NPK and liming doses in the soil, on the growth of Erva-mate, the severity of rot-root and the fungi population of the soil. To do so, an experiment was installed at the green house, in the Forest Nursery of UFSM, using an experimental design completely randomized factorial 4x3x4 (Factor F: Fusarium spp. inoculation; Factor C: soil limestone; Factor A: NPK doses , totaling 48 treatments. The seedlings were cultivated in vases containing 2 kg of soil, classified as ‘Red-Yellow Argisoil’ (clay soil. At the end of the experiment was measured the stem diameter, height of the aerial part, leaves number, aerial dry biomass, root dry biomass and total dry biomass of the seedlings. Also, the soil was collected, from each treatment, for the chemical analysis and the counting of the fungi population. It was observed that the association among application of NPK and liming in the soil hampered the development of Erva-mate seedlings. The analysis of some variables suggests that the limestone absence provided greater resistance of seedlings to the attack of Fusarium spp. or the severity of Fusarium spp. was reduced in lower pH. The fungi population of the soil presented varied behavior depending on the applied treatments.

  4. In vitro and in vivo antagonism of actinomycetes isolated from Moroccan rhizospherical soils against Sclerotium rolfsii: a causal agent of root rot on sugar beet (Beta vulgaris L.).

    Science.gov (United States)

    Errakhi, R; Lebrihi, A; Barakate, M

    2009-08-01

    To evaluate the ability of the isolated actinomycetes to inhibit in vitro plant pathogenic fungi and the efficacy of promising antagonistic isolates to reduce in vivo the incidence of root rot induced by Sclerotium rolfsii on sugar beet. Actinomycetes isolated from rhizosphere soil of sugar beet were screened for antagonistic activity against a number of plant pathogens, including S. rolfsii. Ten actinomycetes out of 195 screened in vitro were strongly inhibitory to S. rolfsii. These isolates were subsequently tested for their ability to inhibit sclerotial germination and hyphal growth of S. roflsii. The most important inhibitions were obtained by the culture filtrate from the isolates J-2 and B-11, including 100% inhibition of sclerotial germination and 80% inhibition of hyphal growth. These two isolates (J-2 and B-11) were then screened for their ability to protect sugar beet against infection of S. rolfsii induced root rot in a pot trial. The treatment of S. rolfsii infested soil with a biomass and culture filtrate mixture of the selected antagonists reduced significantly (P beet. Isolate J-2 was most effective and allowed a high fresh weight of sugar beet roots to be obtained. Both antagonists J-2 and B-11 were classified as belonging to the genus Streptomyces species through morphological and chemical characteristics as well as 16S rDNA analysis. Streptomyces isolates J-2 and B-11 showed a potential for controlling root rot on sugar beet and could be useful in integrated control against diverse soil borne plant pathogens. This investigation showed the role, which actinomycete bacteria can play to control root rot caused by S. rolfsii, in the objective to reduce treatments with chemical fungicides.

  5. Integrated Management of Damping-off, Root and/or Stem Rot Diseases of Chickpea and Efficacy of the Suggested Formula

    Directory of Open Access Journals (Sweden)

    Montaser Fawzy ABDEL-MONAIM

    2011-08-01

    Full Text Available Eleven fungal isolates were isolated from naturally infected chickpea roots collected from different locations in New Valley Governorate (Egypt. The isolated fungi were purified and identified as Rhizoctonia solani (5 isolates, Fusarium solani (4 isolates and Sclerotinia sclerotiorum (2 isolates. The isolated fungi proved their pathogenicity on cv. Giza 3. Response of chickpea cvs. Giza 1, Giza 2, Giza 3, Giza 4, Giza 88, Giza 195, Giza 531 to infection by the tested fungi was significantly varied. Giza 1 was the most resistant one followed by Giza 531, while the other tested cvs. were highly susceptible. Seven biocontrol agents, namely Bacillus subtilis, B. megaterium, B. cereus, Trichoderma viride, T. harzianum, Aspergillus sp., Penicillium sp. isolated from chickpea rhizosphere, were tested for their antagonistic action against the tested pathogens. B. subtilis isolate BSM1, B. megaterium isolate TVM5, T. viride isolate TVM2 and T. harzianum isolate THM4 were the most antagonistic ones to the tested fungi in vitro, while the other isolates were moderate or weak antagonists. The most antagonistic isolates as well as the commercial biocide Rhizo-N were applied as seed treatment for controlling damping-off, root and/or stem rot diseases caused by the tested fungi under greenhouse conditions. The obtained data showed that all tested antagonistic isolates were able to cause significant reduction of damping-off, root and/or stem rot diseases in chickpea plants. T. viride (isolate TVM2 and B. megaterium (isolate BMM5 proved to be the most effective isolates for controlling the diseases. Under field condition, the obtained data indicated that all the tested antagonistic isolates significantly reduced damping-off, root and/or stem rot. T. viride (isolate TVM2 and B. megaterium (isolate BMM5 recorded the highest reduction of damping-off, root and/or stem rot in all sowing dates. Sowing of treated seeds with bioagents in first of November gave the

  6. Biocontrol traits of plant growth suppressive arbuscular mycorrhizal fungi against root rot in tomato caused by Pythium aphanidermatum

    DEFF Research Database (Denmark)

    Larsen, John; Graham, James H.; Cubero, Jaime

    2012-01-01

    Arbuscular mycorrhizal (AM) fungi known to cause plant growth depressions in tomato were examined for their biocontrol effects against root rot caused by Pythium aphanidermatum. The main hypothesis was that plant growth suppressive AM fungi would elicit a defence response in the host plant reducing...... Pythium root rot development. To test this hypothesis a fully factorial experiment was performed with AM fungi (Glomus intraradices, G. mosseae, G. claroideum or nonmycorrhizal), Pythium (± P. aphanidermatum) and harvest (7 and 14 days after pathogen inoculation (dapi)) as the main factors. Two weeks...... growth suppressions, but did not affect PR-1 gene expression or the phosphorous concentration in the host plant. Plants singly inoculated with P. aphanidermatum had an increased PR-1 expression and phosphorous concentration. Among the AM fungi included in the study only G. intraradices reduced...

  7. 丹参根腐病原菌的分离与鉴定%Isolation and identification of root rot pathogen of Salvia miltiorrhiza Bunge

    Institute of Scientific and Technical Information of China (English)

    袁孟娟; 藏香银; 韩军; 陈芳

    2015-01-01

    In order to further understand the variety and biology characteristics of the pathogens of Salvia miltiorrhiza Bunge root rot, one strain of fungi was isolated from the root rot samples of S.miltiorrhiza Bunge by tissue isolation.According to the pathogenicity test and the morphological observation of the pathogen, as well as molecular biological identification, it was identified as Fusarium solani.%为进一步了解丹参( Salvia miltiorrhiza Bunge)根腐病病原菌的种类及生物学特性,采用组织分离法从丹参根腐病样本中分离到1株真菌,经致病性测定、形态学观察和分子生物学鉴定,将其鉴定为腐皮镰刀菌( Fu-sarium solani )。

  8. Organic amendments conditions on the control of Fusarium crown and root rot of asparagus caused by three Fusarium spp

    Energy Technology Data Exchange (ETDEWEB)

    Borrego-Benjumea, A.I.; Melero-Vara, J.M.; Basallote-Ureba, M.J.

    2015-07-01

    Fusarium oxysporum (Fo), F. proliferatum (Fp) and F. solani (Fs) are causal agents associated with roots of asparagus affected by crown and root rot, a disease inflicting serious losses worldwide. The propagule viability of Fusarium spp. was determined on substrate artificially infested with Fo5, Fp3 or Fs2 isolates, amended with either poultry manure (PM), its pellet (PPM), or olive residue compost (ORC) and, thereafter, incubated at 30 or 35°C for different periods. Inoculum viability was significantly affected by these organic amendments (OAs) in combination with temperature and incubation period. The greatest reduction in viability of Fo5 and Fs2 occurred with PPM and loss of viability achieved was higher at 35°C than at 30ºC, and longer incubation period (45 days). However, the viability of Fp3 did not decrease greatly in most of the treatments, as compared to the infested and un-amended control, when incubated at 30ºC. After incubation, seedlings of asparagus Grande´ were transplanted into pots containing substrates infested with the different species of Fusarium. After three months in greenhouse, symptoms severity in roots showed highly significant decreases, but Fp3 caused lower severity than Fo5 and Fs2. Severity reduction was particularly high at 30ºC (by 15 days incubation for Fs2 and by 30-45 days for Fo5), after PPM treatment, as well as PM-2% for Fo5 and Fs2 incubated during 30 and 45 days at both temperatures, and with ORC (15-30 days incubation). Moreover, assessment of plants fresh weight showed significantly high increases in Fo5 and Fs2, with some rates of the three OAs tested, depending on incubat. (Author)

  9. Organic amendments conditions on the control of Fusarium crown and root rot of asparagus caused by three Fusarium spp.

    Directory of Open Access Journals (Sweden)

    Ana I. Borrego-Benjumea

    2015-12-01

    Full Text Available Fusarium oxysporum (Fo, F. proliferatum (Fp and F. solani (Fs are causal agents associated with roots of asparagus affected by crown and root rot, a disease inflicting serious losses worldwide. The propagule viability of Fusarium spp. was determined on substrate artificially infested with Fo5, Fp3 or Fs2 isolates, amended with either poultry manure (PM, its pellet (PPM, or olive residue compost (ORC and, thereafter, incubated at 30 or 35°C for different periods. Inoculum viability was significantly affected by these organic amendments (OAs in combination with temperature and incubation period. The greatest reduction in viability of Fo5 and Fs2 occurred with PPM and loss of viability achieved was higher at 35°C than at 30ºC, and longer incubation period (45 days. However, the viability of Fp3 did not decrease greatly in most of the treatments, as compared to the infested and un-amended control, when incubated at 30ºC. After incubation, seedlings of asparagus `Grande´ were transplanted into pots containing substrates infested with the different species of Fusarium. After three months in greenhouse, symptoms severity in roots showed highly significant decreases, but Fp3 caused lower severity than Fo5 and Fs2. Severity reduction was particularly high at 30ºC (by 15 days incubation for Fs2 and by 30-45 days for Fo5, after PPM treatment, as well as PM-2% for Fo5 and Fs2 incubated during 30 and 45 days at both temperatures, and with ORC (15-30 days incubation. Moreover, assessment of plants fresh weight showed significantly high increases in Fo5 and Fs2, with some rates of the three OAs tested, depending on incubation period and temperature.

  10. Biocontrol bacteria selected by a direct plant protection strategy against avocado white root rot show antagonism as a prevalent trait.

    Science.gov (United States)

    González-Sánchez, M Á; Pérez-Jiménez, R M; Pliego, C; Ramos, C; de Vicente, A; Cazorla, F M

    2010-07-01

    This study was undertaken to study bacterial strains obtained directly for their efficient direct control of the avocado white root rot, thus avoiding prescreening by any other possible mechanism of biocontrol which could bias the selection. A collection of 330 bacterial isolates was obtained from the roots and soil of healthy avocado trees. One hundred and forty-three representative bacterial isolates were tested in an avocado/Rosellinia test system, resulting in 22 presumptive protective strains, all of them identified mainly as Pseudomonas and Bacillus species. These 22 candidate strains were screened in a more accurate biocontrol trial, confirming protection of some strains (4 out of the 22). Analyses of the potential bacterial traits involved in the biocontrol activity suggest that different traits could act jointly in the final biocontrol response, but any of these traits were neither sufficient nor generalized for all the active bacteria. All the protective strains selected were antagonistic against some fungal root pathogens. Diverse bacteria with biocontrol activity could be obtained by a direct plant protection strategy of selection. All the biocontrol strains finally selected in this work were antagonistic, showing that antagonism is a prevalent trait in the biocontrol bacteria selected by a direct plant protection strategy. This is the first report on the isolation of biocontrol bacterial strains using direct plant protection strategy in the system avocado/Rosellinia. Characterization of selected biocontrol bacterial strains obtained by a direct plant protection strategy showed that antagonism is a prevalent trait in the selected strains in this experimental system. This suggests that antagonism could be used as useful strategy to select biocontrol strains. © 2009 The Authors. Journal compilation © 2009 The Society for Applied Microbiology.

  11. Plant growth-promoting rhizobacterial strain-mediated induced systemic resistance in tea (Camellia sinensis (L.) O. Kuntze) through defense-related enzymes against brown root rot and charcoal stump rot.

    Science.gov (United States)

    Mishra, A K; Morang, P; Deka, M; Nishanth Kumar, S; Dileep Kumar, B S

    2014-09-01

    Induction of systemic resistance in host plants through microbes and their bioactive metabolites are attaining popularity in modern agricultural practices. In this regard, individual application of two strains of Pseudomonas, RRLJ 134 and RRLJ 04, exhibited development of induced systemic resistance in tea plants against brown root rot and charcoal stump rot under split root experiments. The experimental findings also confirmed that the cuttings treated with fungal test pathogen and plant growth-promoting rhizobacteria (PGPR) strains survived longer as compared with pathogen-alone-treated cuttings. The enzyme level studies revealed that the presence of PGPR strains reduced the viscosity loss of cellulose and pectin by both the pathogens to a significant level. The activity of defense-related enzymes like L-phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase were also recorded higher in tea cuttings treated with PGPR strains in presence of pathogen. Crude bioactive metabolites isolated from these strains also showed in vitro antagonism against the test pathogens besides reducing the number of diseased plants under gnotobiotic conditions. These findings confirm the utilization of these two strains for induction of systemic resistance against two major root diseases in tea plants under plantation conditions.

  12. Identification and ControI of Root Rot in Wheat%小麦根腐病的识别与防治

    Institute of Scientific and Technical Information of China (English)

    潘万明

    2015-01-01

    Infection cycle and occur-rence regularity of two root rot in wheat (wheat common root rot and wheat Bipo-laris leaf spot and root rot) were intro-duced,and damage symptom and identifi-cation features of each disease were put forward.Then it proposed the correspond-ing control measures from two aspects including agricultural measures and chemical measures.The study aimed to reduce damages of diseases and improve yield and quality of wheat.%介绍了小麦2种常见根腐病———小麦根腐病和小麦蠕孢叶斑根腐病的侵染循环和发生规律,指出各病害的危害症状及识别特征,并从农业防治、化学防治等方面提出了相应的防治措施。为减轻病害危害,提高小麦的产量和品质提供了一定的依据。

  13. Differential responses of vanilla accessions to root rot and colonization by Fusarium oxysporum f. sp. radicis-vanillae.

    Directory of Open Access Journals (Sweden)

    Sayuj eKoyyappurath

    2015-12-01

    Full Text Available Root and stem rot (RSR disease caused by Fusarium oxysporum f. sp. radicis-vanillae (Forv is the most damaging disease of vanilla (Vanilla planifolia and V. ×tahitensis, Orchidaceae. Breeding programs aimed at developing resistant vanilla varieties are hampered by the scarcity of sources of resistance to RSR and insufficient knowledge about the histopathology of Forv. In this work we have i identified new genetic resources resistant to RSR including V. planifolia inbreds and vanilla relatives, ii thoroughly described the colonization pattern of Forv into selected vanilla accessions, confirming its necrotic non-vascular behavior in roots, and iii evidenced the key role played by hypodermis, and particularly lignin deposition onto hypodermal cell walls, for resistance to Forv in two highly resistant vanilla accessions.Two hundred and fifty-four vanilla accessions were evaluated in the field under natural conditions of infection and in controlled conditions using in-vitro plants root-dip inoculated by the highly pathogenic isolate Fo072. For the 26 accessions evaluated in both conditions, a high correlation was observed between field evaluation and in-vitro assay.The root infection process and plant response of one susceptible and two resistant accessions challenged with Fo072 were studied using wide field and multiphoton microscopy. In susceptible V. planifolia, hyphae penetrated directly into the rhizodermis in the hairy root region then invaded the cortex through the passage cells where it induced plasmolysis, but never reached the vascular region. In the case of the resistant accessions, the penetration was stopped at the hypodermal layer. Anatomical and histochemical observations coupled with spectral analysis of the hypodermis suggested the role of lignin deposition in the resistance to Forv. The thickness of lignin constitutively deposited onto outer cell walls of hypodermis was highly correlated with the level of resistance for 21

  14. Abscisic acid in salt stress predisposition to phytophthora root and crown rot in tomato and chrysanthemum.

    Science.gov (United States)

    Dileo, Matthew V; Pye, Matthew F; Roubtsova, Tatiana V; Duniway, John M; Macdonald, James D; Rizzo, David M; Bostock, Richard M

    2010-09-01

    Plants respond to changes in the environment with complex signaling networks, often under control of phytohormones that generate positive and negative crosstalk among downstream effectors of the response. Accordingly, brief dehydration stresses such as salinity and water deficit, which induce a rapid and transient systemic increase in levels of abscisic acid (ABA), can influence disease response pathways. ABA has been associated with susceptibility of plants to bacteria, fungi, and oomycetes but relatively little attention has been directed at its role in abiotic stress predisposition to root pathogens. This study examines the impact of brief salinity stress on infection of tomato and chrysanthemum roots by Phytophthora spp. Roots of plants in hydroponic culture exposed to a brief episode of salt (sodium chloride) stress prior to or after inoculation were severely diseased relative to nonstressed plants. Tomato roots remained in a predisposed state up to 24 h following removal from the stress. An increase in root ABA levels in tomato preceded or temporally paralleled the onset of stress-induced susceptibility, with levels declining in roots prior to recovery from the predisposed state. Exogenous ABA could substitute for salt stress and significantly enhanced pathogen colonization and disease development. ABA-deficient tomato mutants lacked the predisposition response, which could be restored by complementation of the mutant with exogenous ABA. In contrast, ethylene, which exacerbates disease symptoms in some host-parasite interactions, did not appear to contribute to the predisposition response. Thus, several lines of evidence support ABA as a critical and dominant factor in the salinity-induced predisposition to Phytophthora spp. infection.

  15. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan.

    Directory of Open Access Journals (Sweden)

    Mitsuteru Akiba

    Full Text Available Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands.

  16. Mycofumigation with Oxyporus latemarginatus EF069 for control of postharvest apple decay and Rhizoctonia root rot on moth orchid.

    Science.gov (United States)

    Lee, S O; Kim, H Y; Choi, G J; Lee, H B; Jang, K S; Choi, Y H; Kim, J-C

    2009-04-01

    To characterize the volatile antifungal compound produced by Oxyporus latemarginatus EF069 and to examine in vitro and in vivo fumigation activity of the fungus. An antifungal volatile-producing strain, O. latemarginatus EF069 inhibited the mycelial growth of Alternaria alternata, Botrytis cinerea, Colletotrichum gloeosporioides, Fusarium oxysporum f. sp. lycopersici, and Rhizoctonia solani by mycofumigation. An antifungal volatile compound was isolated from the hexane extract of wheat bran-rice hull cultures of O. latemarginatus EF069 by repeated silica gel column chromatography and identified as 5-pentyl-2-furaldehyde (PTF). The purified PTF inhibited mycelial growth of R. solani in a dose-dependent manner. The mycofumigation with solid cultures of EF069 also reduced effectively the development of postharvest apple decay caused by B. cinerea and Rhizoctonia root rot of moth orchid caused by R. solani. Oxyporus latemarginatus EF069 showed in vitro and in vivo fumigation activity against plant pathogenic fungi by producing 5-pentyl-2-furaldehyde. Oxyporus latemarginatus EF069 producing an antifungal volatile compound may be used as a biofumigant for the control of fungal plant diseases.

  17. Genetic Differentiation and Spatial Structure of Phellinus noxius, the Causal Agent of Brown Root Rot of Woody Plants in Japan.

    Science.gov (United States)

    Akiba, Mitsuteru; Ota, Yuko; Tsai, Isheng J; Hattori, Tsutomu; Sahashi, Norio; Kikuchi, Taisei

    2015-01-01

    Phellinus noxius is a pathogenic fungus that causes brown root rot disease in a variety of tree species. This fungus is distributed in tropical and sub-tropical regions of Southeast and East Asia, Oceania, Australia, Central America and Africa. In Japan, it was first discovered on Ishigaki Island in Okinawa Prefecture in 1988; since then, it has been found on several of the Ryukyu Islands. Recently, this fungus was identified from the Ogasawara (Bonin) Islands, where it has killed trees, including rare endemic tree species. For effective control or quarantine methods, it is important to clarify whether the Japanese populations of P. noxius are indigenous to the area or if they have been introduced from other areas. We developed 20 microsatellite markers from genome assembly of P. noxius and genotyped 128 isolates from 12 of the Ryukyu Islands and 3 of the Ogasawara Islands. All isolates had unique genotypes, indicating that basidiospore infection is a primary dissemination method for the formation of new disease foci. Genetic structure analyses strongly supported genetic differentiation between the Ryukyu populations and the Ogasawara populations of P. noxius. High polymorphism of microsatellite loci suggests that Japanese populations are indigenous or were introduced a very long time ago. We discuss differences in invasion patterns between the Ryukyu Islands and the Ogasawara Islands.

  18. Calonectria spp. causing leaf spot, crown and root rot of ornamental plants in Tunisia

    NARCIS (Netherlands)

    Lombard, L.; Polizzi, G.; Guarnaccia, V.; Vitale, A.; Crous, P.W.

    2012-01-01

    Calonectria spp. are important pathogens of ornamental plants in nurseries, especially in the Northern Hemisphere. They are commonly associated with a wide range of disease symptoms of roots, leaves and shoots. During a recent survey in Tunisia, a number of Calonectria spp. were isolated from tissue

  19. Calonectria spp. causing leaf spot, crown and root rot of ornamental plants in Tunisia

    NARCIS (Netherlands)

    Lombard, L.; Polizzi, G.; Guarnaccia, V.; Vitale, A.; Crous, P.W.

    2011-01-01

    Calonectria spp. are important pathogens of ornamental plants in nurseries, especially in the Northern Hemisphere. They are commonly associated with a wide range of disease symptoms of roots, leaves and shoots. During a recent survey in Tunisia, a number of Calonectria spp. were isolated from tissue

  20. First report of root rot caused by Phytopythium helicoides on pistachio rootstock in California

    Science.gov (United States)

    We examined pathogenicity of Phytopythium helicoides on UCB-1 rootstock to investigate its role in root disease and collapse observed on potted pistachio plants. Approximately 25 potted 2-year-old pistachio rootstock trees in a Kern County, CA, research plot maintained outdoors and irrigated to cont...

  1. Biocontrol of tomato foot and root rot by Pseudomonas bacteria in stonewool

    NARCIS (Netherlands)

    Validov, Shamil

    2007-01-01

    The research described in this thesis shows that the enrichment technique based on competitive root tip colonization allows the isolation of bacteria which can protect plants from TFRR through the mechanism competition for nutrients (and niches). The efficacy of biocontrol of one of these strains,

  2. Control of the root-rot and root-knot disease complex by Pseudomonas aeruginosa: impact of bacterial rhizosphere colonization

    Directory of Open Access Journals (Sweden)

    I. A. Siddiqui

    2013-12-01

    Full Text Available The potential of 3 Pseudomonas aeriuginosa strains as biocontrol agents of rootinfecting fungi Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani and the root-knot nematode Meloidogyne javanica was tested on chili and uridbean under greenhouse conditions. All the three strains significantly reduced nematode populations in soil, invasion, multiplication and gall formation due to M.javanica. Root infection by fungi was also effectively suppressed following P.aeruginosa application. Bacterial antagonists exhibited better biocontrol and growth promoting activity in 15-day-old plants than did those harvested at 30 or 45 days. Population of the bacterium in the rhizosphere declined rapidly after 15 days of nematode inoculation. Strain Pa-5 showed maximum nodulation in 15-day-old samplings while strain Pa-7 showed highest number of nodules in 30 and 45-day-old uridbean plants.

  3. Bipolaris sorokiniana (teleomorph Cochliobolus Sativus: Causer of barley leaf lesions and root rot in Macedonia

    Directory of Open Access Journals (Sweden)

    Karov Ilija K.

    2009-01-01

    Full Text Available Diseased barley plants (Hordeum vulgare, were noticed in the area of Kumanovo, Bitola, Probistip, Skopje and Kocani, at the beginning of March, 2006. Our investigations were carried out in the period from 2006 to 2009. The plants were highly diseased, probably in the stage of germination, dwarfed with necrotic leaves and with poorly developed root. A rotten root collar was noticed notice in some plants, which could be easily pulled out from the soil. Plants infected in a later developing stage became yellow from the top of the leaf, and many brown-olive, oval shape lesions were noticed. Conidia of Bipolaris sorokiniana (Sacc. Shoen., were isolated from symptomatic lesions. Pseudothecia with asci and ascospores from teleomorph Cochliobolus sativus, were found on the barley straw in the same field the previous year.

  4. Tobacco leaf spot and root rot caused by Rhizoctonia solani Kühn.

    Science.gov (United States)

    Gonzalez, Marleny; Pujol, Merardo; Metraux, Jean-Pierre; Gonzalez-Garcia, Vicente; Bolton, Melvin D; Borrás-Hidalgo, Orlando

    2011-04-01

    Rhizoctonia solani Kühn is a soil-borne fungal pathogen that causes disease in a wide range of plants worldwide. Strains of the fungus are traditionally grouped into genetically isolated anastomosis groups (AGs) based on hyphal anastomosis reactions. This article summarizes aspects related to the infection process, colonization of the host and molecular mechanisms employed by tobacco plants in resistance against R. solani diseases. Teleomorph: Thanatephorus cucumeris (Frank) Donk; anamorph: Rhizoctonia solani Kühn; Kingdom Fungi; Phylum Basidiomycota; Class Agaricomycetes; Order Cantharellales; Family Ceratobasidiaceae; genus Thanatephorus. Somatic hyphae in culture and hyphae colonizing a substrate or host are first hyaline, then buff to dark brown in colour when aging. Hyphae tend to form at right angles at branching points that are usually constricted. Cells lack clamp connections, but possess a complex dolipore septum with continuous parenthesomes and are multinucleate. Hyphae are variable in size, ranging from 3 to 17 µm in diameter. Although the fungus does not produce any conidial structure, ellipsoid to globose, barrel-shaped cells, named monilioid cells, 10-20 µm wide, can be produced in chains and can give rise to sclerotia. Sclerotia are irregularly shaped, up to 8-10 mm in diameter and light to dark brown in colour. Symptoms in tobacco depend on AG as well as on the tissue being colonized. Rhizoctonia solani AG-2-2 and AG-3 infect tobacco seedlings and cause damping off and stem rot. Rhizoctonia solani AG-3 causes 'sore shin' and 'target spot' in mature tobacco plants. In general, water-soaked lesions start on leaves and extend up the stem. Stem lesions vary in colour from brown to black. During late stages, diseased leaves are easily separated from the plant because of severe wilting. In seed beds, disease areas are typically in the form of circular to irregular patches of poorly growing, yellowish and/or stunted seedlings. Knowledge is scarce

  5. Molecular variability among isolates of Fusarium oxysporum associated with root rot disease of Agave tequilana.

    Science.gov (United States)

    Vega-Ramos, Karla L; Uvalle-Bueno, J Xavier; Gómez-Leyva, Juan F

    2013-04-01

    In this study, 115 isolates of Fusarium oxysporum from roots of Agave tequilana Weber cv azul plants and soil in commercial plantations in western Mexico were characterized using morphological and molecular methods. Genetic analyses of monosporic isolates included restriction enzyme analysis of rDNA (ARDRA) using HaeIII and HinfI, and genetic diversity was determined using Box-PCR molecular markers. Box-PCR analysis generated 14 groups. The groups correlated highly with the geographic location of the isolate and sample type. These results demonstrate the usefulness of ARDRA and Box-PCR techniques in the molecular characterization of the Fusarium genus for the discrimination of pathogenic isolates.

  6. CHANGES IN THE BIOCHEMICAL CONSTITUENTS OF CARROT ROOTS DUE TO BACTERIAL SOFT ROT

    Directory of Open Access Journals (Sweden)

    V. K. Parthiban

    2013-03-01

    Full Text Available Carrot is a rich source of nutrients. The carrot contains carotene and lycopene, which gives bright color to the roots. The quality of the carrots was assessed based on the carotene, lycopene and other biochemical constituents like sugars, starch and protein. To study the effect of various isolates of the Erwinia carotovora var. carotovora on the above biochemical constituents, the pathogens were inoculated and the contents were analyzed separately at 1, 2, 3, 4, 5 days after inoculation. The contents of β-carotene increased significantly due to all the three isolates of the pathogen and the Coimbatore isolate recorded highest of 36.03 per cent. A same trend was also observed in the lycopene content with 93.55 per cent increase over control. The contents of total and reducing sugars were found to significantly increase due to inoculation with the pathogen. The starch content showed a decreasing trend in all the isolates tested. The maximum reduction of 62.98 per cent was observed in the roots inoculated with Coimbatore isolate.

  7. Improvement of Biocontrol of Damping-off and Root Rot/Wilt of Faba Bean by Salicylic Acid and Hydrogen Peroxide.

    Science.gov (United States)

    Abdel-Monaim, Montaser Fawzy

    2013-03-01

    Rhizoctonia solani, Fusarium solani, F. oxysporum, and Macrophomina phaseolina were found to be associated with root rott and wilt symptoms of faba bean plants collected from different fieldes in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride and Bacillus megaterium) and chemical inducers (salicylic acid [SA] and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promoting of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi. Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA + B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/wilt severity and increased of survival plants. Also, these treatments increased fresh and weights of the survival plants in pots compared with control. The combination between biocontrol agents and chemical inducers were more effective than used of them individually and SA + T. viride was the best treatment in this respect. Also, under field conditions, all these treatments significantly increased growth parameters (plant height and number of branches per plant) and yield components (number of pods per plant and number of seeds per plant, weight of 100 seeds and total yield per feddan) and protein content in both seasons (2010~2011 and 2011~2012). Faba bean seeds soaked in SA + T. viride and SA + B. megaterium were recorded the highest growth parameters and yield components. Generally, the

  8. Disease Investigation and Identification of the Pathogens Causing Root Rot of Tussilago farfaral%款冬花根腐病的发病情况与病原鉴定

    Institute of Scientific and Technical Information of China (English)

    张爱香; 马海莲; 李雪萍; 仝在利; 李世东; 王晓涛

    2011-01-01

    为找出引起款冬花根腐病的主要病原,对其综合防治提供参考依据,通过田间调查款冬花根腐病的症状以及室内病原物的分离、培养、纯化、回接试验.结果表明:款冬花根腐病的症状主要是萎蔫和根腐,引起根腐病的病原主要是立枯丝核菌(Rhizoctonia solani)、灰葡萄孢菌(Botrytis cinerea)、尖孢镰孢菌(Fusarium oxysporum Schlecht).%Symptom of Tussilago far faral root rot was investigated in the field and pathogens of Tussilago farfaral root rot was isolated, cultured, purified and re-inoculated in the laboratory to find out the main pathogens causing root rot of Tussilago farfaral and provide a reference for its comprehensive control. The results showed that the symptoms of the disease were expressed as wilt and root rot. Rhizoctonia solani, Botrytis cinerea and Fusarium oxysporum were the major pathogens of Tussilago far faral root rot.

  9. 麻疯树根腐病的病原鉴定%Identification of the Causal Agent of Root Rot Disease of Jatropha curcas L.in Luodian County

    Institute of Scientific and Technical Information of China (English)

    吴跃开; 欧国腾; 朱秀娥; 余金勇

    2011-01-01

    [Objective] The aim was to identify the causal agent of root rot disease of Jatropha curcas L. In Luodian County. [ Method ] Typical root rot samples were collected from different planting areas of Jatropha curcas L. In Luodian County, and then pathogens of the root rot samples were isolated, cultured, made a pathogenic test and observed under the microscope. [Result] The causal agent of root rot disease of Jatropha curcas L. Was Fusarium solani ( Martius) Appel & Wollenweber. [ Conclusion] The research provides reference for the effective prevention and control of root rot disease of Jatropha curcas L. In Luodian County.%[目的]鉴定麻疯树根腐病的病原.[方法]从罗甸县境内的不同麻疯树种植地点采集典型的根腐病病根标本,并对其病原物进行了分离培养、致病性测试以及形态特征观察.[结果]最终确认麻疯树根腐病病原菌为腐皮镰孢菌(Fusarium solani).[结论]为贵州罗甸县境内麻疯树根腐病的有效防治提供了参考.

  10. Transgenic sweet potato expressing thionin from barley gives resistance to black rot disease caused by Ceratocystis fimbriata in leaves and storage roots.

    Science.gov (United States)

    Muramoto, Nobuhiko; Tanaka, Tomoko; Shimamura, Takashi; Mitsukawa, Norihiro; Hori, Etsuko; Koda, Katsunori; Otani, Motoyasu; Hirai, Masana; Nakamura, Kenzo; Imaeda, Takao

    2012-06-01

    Black rot of sweet potato caused by pathogenic fungus Ceratocystis fimbriata severely deteriorates both growth of plants and post-harvest storage. Antimicrobial peptides from various organisms have broad range activities of killing bacteria, mycobacteria, and fungi. Plant thionin peptide exhibited anti-fungal activity against C. fimbriata. A gene for barley α-hordothionin (αHT) was placed downstream of a strong constitutive promoter of E12Ω or the promoter of a sweet potato gene for β-amylase of storage roots, and introduced into sweet potato commercial cultivar Kokei No. 14. Transgenic E12Ω:αHT plants showed high-level expression of αHT mRNA in both leaves and storage roots. Transgenic β-Amy:αHT plants showed sucrose-inducible expression of αHT mRNA in leaves, in addition to expression in storage roots. Leaves of E12Ω:αHT plants exhibited reduced yellowing upon infection by C. fimbriata compared to leaves of non-transgenic Kokei No. 14, although the level of resistance was weaker than resistance cultivar Tamayutaka. Storage roots of both E12Ω:αHT and β-Amy:αHT plants exhibited reduced lesion areas around the site inoculated with C. fimbriata spores compared to Kokei No. 14, and some of the transgenic lines showed resistance level similar to Tamayutaka. Growth of plants and production of storage roots of these transgenic plants were not significantly different from non-transgenic plants. These results highlight the usefulness of transgenic sweet potato expressing antimicrobial peptide to reduce damages of sweet potato from the black rot disease and to reduce the use of agricultural chemicals.

  11. 勃利县红松根朽病防治技术的研究%Control Technology of Root-rot of Pinus koraiensis in Boli County

    Institute of Scientific and Technical Information of China (English)

    董双波; 曹月平; 朱宝珠

    2011-01-01

    通过调查、观测,掌握了红松根朽病在勃利县林区发病规律以及环境因素对该病害的影响。结果表明,红松根朽病的发病规律为:郁闭度大的林分病害较重,阴坡重于阳坡,山中下腹重于山上腹;使用树干基部涂药和根部注药相结合的方法防治效果最好,防治效果达95%以上。%Through survey observation,occurrence pattern of roo-rot of Pinus koraiensis in Boli county influence of environmental factors on this disease were mastered.Occurrence pattern of root-rot of Pinus koraiensis is that: plant disease of stand with large canopy density is severe;plant disease on shady slope are severe than that on sunny slope;plant disease on middle lower part of the mountain is severe than that on upper part of the mountain;combining the method of drug-coated on the base of the trunk and root injection can get the optimal control effect,which being 95% or more.

  12. Isolation and Pathogenicity of the Pathogens Causing Root Rot Disease of Atractylodes macrocephala Koidz%白术根腐病菌分离及致病性研究

    Institute of Scientific and Technical Information of China (English)

    杨成前; 吴中宝; 李品明; 韦中强; 肖杰易

    2012-01-01

    在同一地块通过对白术根腐病的发病情况进行调查,确定白术根腐病分为湿腐和干腐2种症状,湿腐为主要症状类型,在田间所占比例达69.68%.通过对30个病株样本进行病原分离,共分离得到131个菌株,12种分离菌中有7种对白术具有致病力,其中尖孢镰刀菌(Fusarium oxysporum)和茄病镰刀菌(F.solani)能产生白术根腐病的典型症状.尖孢镰刀菌为根腐病主要致病菌,并能导致两种症状,致病率达90%;茄病镰刀菌危害症状为湿腐,致病率为30%.%Investigation in one Atractylodes macrocephala plot showed that root rot of the plants had two different types of symptoms:dry rot and wet rot,and wet rot was the main symptom,accounting for 69.68% of the total.Altogether,131 fungus strains were isolated from 30 diseased plant samples.They belonged to 12 fungus species,of which 7 was pathogenic to A.macrocephala.Infection by Fusarium oxysporum and F.solani would produce typical symptoms of root rot.The main pathogen was F.oxysporum,which could cause both dry rot and wet rot,with a morbidity of 90%.F.solani had a morbidity of 30%,and its symptom was wet rot.

  13. Do jasmonates play a role in arbuscular mycorrhiza-induced local bioprotection of Medicago truncatula against root rot disease caused by Aphanomyces euteiches?

    Science.gov (United States)

    Hilou, Adama; Zhang, Haoqiang; Franken, Philipp; Hause, Bettina

    2014-01-01

    Bioprotective effects of mycorrhization with two different arbuscular mycorrhizal (AM) fungi, Funneliformis mosseae and Rhizophagus irregularis, against Aphanomyces euteiches, the causal agent of root rot in legumes, were studied in Medicago truncatula using phenotypic and molecular markers. Previous inoculation with an AM-fungus reduced disease symptoms as well as the amount of pathogen within roots, as determined by the levels of A. euteiches rRNA or transcripts of the gene sterol C24 reductase. Inoculation with R. irregularis was as efficient as that with F. mosseae. To study whether jasmonates play a regulatory role in bioprotection of M. truncatula by the AM fungi, composite plants harboring transgenic roots were used to modulate the expression level of the gene encoding M. truncatula allene oxide cyclase 1, a key enzyme in jasmonic acid biosynthesis. Neither an increase nor a reduction in allene oxide cyclase levels resulted in altered bioprotection by the AM fungi against root infection by A. euteiches. These data suggest that jasmonates do not play a major role in the local bioprotective effect of AM fungi against the pathogen A. euteiches in M. truncatula roots.

  14. The influence of soil moisture and Rhizoctonia solani anastomosis and intraspecific group on the incidence of damping-off and the incidence and severity of Rhizoctonia crown and root rot in sugar beet

    Science.gov (United States)

    Rhizoctonia crown and root rot (Rhizoctonia solani) reduces plant stands, sugar quality and yield in sugar beet. To evaluate the influence of R. solani anastomosis (AG) and intraspecific groups and soil moisture on disease incidence and severity, a field trial was established in Ridgetown, Ontario, ...

  15. Development of amplified fragment length polymorphism (AFLP)-derived specific primer for the detection of Fusarium solani aetiological agent of peanut brown root rot.

    Science.gov (United States)

    Casasnovas, F; Fantini, E N; Palazzini, J M; Giaj-Merlera, G; Chulze, S N; Reynoso, M M; Torres, A M

    2013-06-01

    The objective of this work was to design an amplified fragment length polymorphism (AFLP)-derived specific primer for the detection of Fusarium solani aetiological agent of peanut brown root rot (PBRR) in plant material and soil. Specific primers for the detection of the pathogen were designed based on an amplified region using AFLPs. The banding patterns by AFLPs showed that isolates from diseased roots were clearly distinguishable from others members of the F. solani species complex. Many bands were specific to F. solani PBRR, one of these fragments was selected and sequenced. Sequence obtained was used to develop specific PCR primers for the identification of pathogen in pure culture and in plant material and soil. Primer pair FS1/FS2 amplified a single DNA product of 175 bp. Other fungal isolates occurring in soil, included F. solani non-PBRR, were not detected by these specific primers. The assay was effective for the detection of pathogen from diseased root and infected soils. The designed primers for F. solani causing PBRR can be used in a PCR diagnostic protocol to rapidly and reliably detect and identify this pathogen. These diagnostic PCR primers will aid the detection of F. solani causing PBRR in diseased root and natural infected soils. The method developed could be a helpful tool for epidemiological studies and to avoid the spread of this serious disease in new areas. © 2013 The Society for Applied Microbiology.

  16. Variation of Saponins in Panax notoginseng Root Rot Diseases by LC -MS%LC -MS 分析三七根腐病的皂苷类成分变化

    Institute of Scientific and Technical Information of China (English)

    泰瑞清; 谈文状; 杨恩; 冯阳; 李海舟

    2015-01-01

    LC -MS method is used to study saponins in normal and root rot of P.notoginseng.and to meas-ure the concentration of H2 O2 and MDA in fresh herbs as a means to find out the possible reason for the change.The LC -MS analysis shows that 13 peaks in the normal of P.notoginseng are identified,and 7 new compounds from the root rot of P.notoginseng are detected.These new compounds are oxidation prod-ucts from saponins.Moreover,the levels of oxidation are significantly increased after being infected root rot diseases (P <0.01 ).The oxidation products of saponins from root rot P.notoginseng are probably caused by root rot diseases.%以高分辨的液质联用(LC -MS)技术分析正常三七和根腐病三七中皂苷类成分差异,检测新鲜药材中过氧化氢(H2 O2)和丙二醛(MDA)的浓度,探讨其变化可能的原因.正常三七中确定13个色谱峰,而根腐病三七中新产生7种成分,多为三七皂苷的氧化产物.此外,发现根腐病三七较正常的氧化水平显著提高(P <0.01).推测根腐病三七的皂苷类成分变化可能是由于病害后引起氧化水平升高而形成的氧化产物.

  17. Antagonism of local isolates of Trichoderna spp.on citrus root rot disease by Fusarium solani in the mekong delta of vietnam

    Institute of Scientific and Technical Information of China (English)

    Duong Minh; Jozef Coosemans; Le Lam Cuong; Ester Vandersmissen; Pham Van Kim

    2004-01-01

    @@ The local isolates of Trichoderrma spp. and Fusariun solani were colected from citrus orchards in the Mekong delta of Vietnam and isolated on PDA, PDB and TSM medium for antagonism and Koch's postulate testing. The results showed that the high chitinolytic enzymes content of Trichoderma isolates can antagonise with Fusarium solani isolates by preventing the germination of Fusarium macroconidia in in-vitro condition. There are five promising isolates of Trichoderna spp. having high antagonism with Fusarium solani. These Trichoderma isolates also grew well in rice straws, maize stems, weeds and water hyacinth biowaste materials. These results supply the promising trend for biological control of root rot disease on citrus orchards of the Mekong delta.

  18. Comparative effect of partial root-zone drying and deficit irrigation on incidence of blossom-end rot in tomato under varied calcium rates

    DEFF Research Database (Denmark)

    Sun, Yanqi; Feng, Hao; Liu, Fulai

    2013-01-01

    This study investigated the comparative effects of reduced irrigation regimes—partial root-zone drying (PRD) and conventional deficit irrigation (DI)—on the incidence of blossom-end rot (BER) in tomato (Solanum lycopersicum L.) under three Ca-fertilization rates: 0, 100, and 200mg Ca kg–1 soil...... xylem sap abscisic acid concentration, lower stomatal conductance, and higher plant water status in the PRD in relation to the DI plants might have contributed to the increased fruit Ca uptake, and could have reduced BER development in tomato fruits. Therefore, under conditions with limited freshwater...... resources, application of PRD irrigation could be a promising approach for saving water and for preventing BER development in tomatoes....

  19. Biological Control of Fusarium oxysporum f. sp. melonis, the Causal Agent of Root Rot Disease of Greenhouse Cucurbits in Kerman Province of Iran

    Directory of Open Access Journals (Sweden)

    Sara Shafii Bafti

    2005-01-01

    Full Text Available Antagonistic activity of 178 soil actinomycete isolates was assayed against Fusarium oxysporum f. sp. melonis Schlecht, Emend (Snyde and Hansen cause of root rot and fusarium wilt of greenhouse cucurbits in Kerman Province, southeast of Iran. From tested isolates, Streptomyces olivaceus (strain 115 showed anti-fusarium activity revealed through screening and bioassays by agar disk and well-diffusion methods. The active strain was grown in submerged cultures for determination of growth curve and preparation of crude extract for further biological characterizations. Antifungal activity was fungistatic type on the pathogen mycelia. It is prominent that amending greenhouse soil mix with the S. olivaceus (strain 115 will reduce crop losses by the pathogen.

  20. Managing Phytophthora crown and root rot on tomato by pre-plant treatments with biocontrol agents, resistance inducers, organic and mineral fertilizers under nursery conditions

    Directory of Open Access Journals (Sweden)

    Giovanna GILARDI

    2014-09-01

    Full Text Available Five trials were carried out under greenhouse conditions to test the efficacy of spray programmes based on biocontrol agents, phosphite-based fertilizers and a chemical inducer of resistance (acibenzolar-S-methyl, phosethyl-Al to control crown and root rot of tomato incited by Phytophthora nicotianae. The best disease control, under high disease pressure resulting from artificial inoculation, was obtained with three pre-plant leaf sprays at 7 d intervals with acibenzolar-S-methyl and with two mineral phosphite-based fertilizers. The disease reduction achieved was similar to that obtained with a single application of azoxystrobin and metalaxyl-M. Phosetyl-Al and the biocontrol agents Glomus spp. + Bacillus megaterium + Trichoderma, B. subtilis QST713, B. velezensis IT45 and the mixture T. asperellum ICC012 + T. gamsii ICC080 provided a partial disease control. Brassica carinata pellets did not control the disease.

  1. Impact of motility and chemotaxis features of the rhizobacterium Pseudomonas chlororaphis PCL1606 on its biocontrol of avocado white root rot.

    Science.gov (United States)

    Polonio, Álvaro; Vida, Carmen; de Vicente, Antonio; Cazorla, Francisco M

    2017-06-01

    The biocontrol rhizobacterium Pseudomonas chlororaphis PCL1606 has the ability to protect avocado plants against white root rot produced by the phytopathogenic fungus Rosellinia necatrix. Moreover, PCL1606 displayed direct interactions with avocado roots and the pathogenic fungus. Thus, nonmotile (flgK mutant) and non-chemotactic (cheA mutant) derivatives of PCL1606 were constructed to emphasize the importance of motility and chemotaxis in the biological behaviour of PCL1606 during the biocontrol interaction. Plate chemotaxis assay showed that PCL1606 was attracted to the single compounds tested, such as glucose, glutamate, succinate, aspartate and malate, but no chemotaxis was observed to avocado or R. necatrix exudates. Using the more sensitive capillary assay, it was reported that smaller concentrations (1 mM) of single compounds elicited high chemotactic responses, and strong attraction was confirmed to avocado and R. necatrix exudates. Finally, biocontrol experiments revealed that the cheA and fglK derivative mutants reduced root protection against R. necatrix, suggesting an important role for these biological traits in biocontrol by P. chlororaphis PCL1606. [Int Microbiol 20(2):94-104 (2017)]. Copyright© by the Spanish Society for Microbiology and Institute for Catalan Studies.

  2. Applications of volatile compounds acquired from Muscodor heveae against white root rot disease in rubber trees (Hevea brasiliensis Müll. Arg.) and relevant allelopathy effects.

    Science.gov (United States)

    Siri-Udom, Sakuntala; Suwannarach, Nakarin; Lumyong, Saisamorn

    The bioactive compounds of the volatile metabolite-producing endophytic fungus, Muscodor heveae, were examined by the process of biofumigation for the purposes of controlling white root rot disease in rubber trees (Hevea brasiliensis Müll. Arg.). Volatile organic compounds (VOCs) of M. heveae possess antimicrobial activity against Rigidoporus microporus in vitro with 100 % growth inhibition. The synthetic volatile compounds test confirmed that the major component, 3-methylbutan-1-ol, and the minor compounds, 3-methylbutyl acetate and 2-methylpropanoic acid, inhibited root and shoot growth in the tested plants 3-methylbutan-1-ol showed ED50 value and MIQ value on seed germination of ruzi grass, Arabidopsis thaliana Col-0 and tomato at 10, 5 and 5 μL(-1) airspace, respectively. In vivo tests were carried out under greenhouse conditions using M. heveae inoculum fumigated soil that had been inoculated with R. microporus inoculum. After which, all seven treatments were compared. Significant differences were observed with a disease score at 150 d after treatment. Biofumigation by M. heveae showed great suppression of the disease. Biocontrol treatments; RMH40 (40 g kg(-1)M. heveae inoculum) and RMH80 (80 g kg(-1)M. heveae inoculum) were not found to be significantly different when compared with fungicide treatment (RT) and the non-infected control, but results were found to be significantly different from R. microporus infested (R) treatment. RMH40 and RMH80 revealed a low disease scores with a high survival rate of rubber tree seedling at 100 %, while R treatment showed the highest disease score of 4.8 ± 0.5 with a survival rate of rubber tree seedling at 25 %. The infected roots, appearing as a white colour. We have concluded that the bioactive VOCs of M. heveae would be an alternative method for the control of white root rot disease in rubber trees. Copyright © 2017 British Mycological Society. Published by Elsevier Ltd. All rights reserved.

  3. 首次报道由异丝腐霉(Pythium diclinum)引起的烟草根腐病%First Report on Root Rot of Tobacco Caused by Pythium diclinum

    Institute of Scientific and Technical Information of China (English)

    劳超; 刘云龙; 谢勇; 王力; 田泽宇; 孔聪聪; 兰建强

    2012-01-01

    For the purpose of ascertaining the pathogen which caused root rot of tobacco seedling in floating system in Yanglin Town, Kunming City, Yunnan Province, the isolates that caused root rot in seedlings of tobacco floating were obtained from samples that they were fetched from three points of the tobacco NC297 seedling in floating system base and 10 samples were fetched from each point. These samples were analyzed by pathogenicity test, characteristic identified and 5. 8 rDNA-ITS sequence. Incidence rate of root rot of tobacco seedling was 100% . The homology between 5. 8 rDNA-ITS sequence of the pathogen and 5. 8 rDNA-ITS sequence of GenBank: AY666087. 1 (Pythium diclinum Tokunaga in Ito & Tokunaga) was 99% . The pathogen which was induced by the pieces of cucumber could generate a lot of spores. Pythium diclinum was identified to be the pathogen of root rot of tobacco seedlings in floating system. According to the symptoms and pathogen, the disease was defined as the root rot of tobacco seedling in floating system which was caused by P. Diclinum. This is the first report of root rot of tobacco caused by P. Diclinum.%为了明确引起云南省昆明市杨林镇烟草漂浮育苗过程中出现的根腐病的病原,在该烟草漂浮育苗基地取3点,分别在各点采集病株10个样本,烟草品种为NC297,对样本进行了病原菌分离、致病性测定、形态学鉴定和5.8 rDNA-ITS序列分析.结果表明,致病性试验中烟苗发病率为100%;病原菌的5.8 rDNA-ITS序列与GenBank:AY666087.1(Pythium diclinum Tokunaga in Ito&Tokunaga)同源性为99%;异丝腐霉通过黄瓜片诱导后能产生大量孢子;引起该烟草漂浮育苗根腐病的病原菌为异丝腐霉(Pythium diclinum);根据症状和病原菌,将此病害定为由异丝腐霉(Pythium diclinum)引起的烟草漂浮育苗根腐病;异丝腐霉引起烟草根腐病为首次报道.

  4. Biocontrol de la pudrición de raíz de nochebuena de interior con Trichoderma spp. Root rot biocontrol for indoor poinsettia with Trichoderma spp.

    Directory of Open Access Journals (Sweden)

    Felipe de Jesús Osuna-Canizalez

    2012-06-01

    Full Text Available En Morelos, la pudrición de la raíz causada por Fusarium spp., es una de las principales enfermedades de la nochebuena de interior. Por su efecto devastador, en su prevención o control se realizan aplicaciones frecuentes de productos químicos, con los riesgos inherentes a la salud humana y al ambiente. En la búsqueda de alternativas bioracionales al manejo de esta enfermedad, se realizó un ensayo en el que se evaluaron tres cepas comerciales de Trichoderma spp., en tres diferentes sustratos: S1= "tierra de hoja" (70% v/v+tezontle grueso (15% v/v+tezontle fino (10% v/v+agrolita (5% v/v; S2= turba (80% v/v+ fibra de coco (20% v/v; S3= "tierra de hoja" (70% + "tepojal" (30%, en las variedades comerciales más comunes, Freedom Red y Prestige Red. Se utilizó un diseño factorial de tratamientos 4 x 3 x 2 y los tratamientos resultantes se evaluaron en un diseño completamente al azar con seis repeticiones. Respecto a la incidencia de pudrición de la raíz, las cepas comerciales de Trichoderma spp., no mostraron diferencias entre sí ni con el testigo químico. La pudrición de la raíz estuvo asociada con S2, debido a una baja capacidad de aireación, y sólo se presentó en Prestige Red. La población (UFC g-¹ de Trichoderma spp., en el sustrato al término del ciclo, fue igual (pIn Morelos, root rot caused by Fusarium spp., is one of the main diseases of indoor poinsettia. In order to prevent or control its devastating effect, frequent applications of chemical products are performed, with inherent risks to human health and environment. In quest for alternative biorational options, an essay in which three commercial strains of Trichoderma spp., was done, in three different substrates: S1= "organic soil" (70% v/v+thick tezontle (15% v/v+thin tezontle (10% v/v+agrolita (5% v/v; S2= peat moss (80% v/v+ coconut fiber (20% v/v; S3= "organic soil" (70%+"tepojal" (30%, in most common commercial varieties, Freedom Red and Prestige Red. A factorial

  5. Trichoderma spp. decrease Fusarium root rot in common bean Trichoderma spp. reduzem a podridão-radicular de Fusário em feijoeiro comum

    Directory of Open Access Journals (Sweden)

    Hudson Teixeira

    2012-12-01

    Full Text Available The effectiveness of six Trichoderma-based commercial products (TCP in controlling Fusarium root rot (FRR in common bean was assessed under field conditions. Three TCP, used for seed treatment or applied in the furrow, increased seedling emergence as much as the fungicide fludioxonil. FRR incidence was not affected, but all TCP and fludioxonil reduced the disease severity, compared to control. Application of Trichoderma-based products was as effective as that of fludioxonil in FRR management.A eficácia de seis produtos comerciais à base de Trichoderma (PCT no controle da podridão-radicular-seca do feijoeiro (PRS foi avaliada em condições de campo. Três PCT, usados no tratamento de sementes ou aplicados no sulco de plantio, aumentaram a emergência das plântulas tanto quanto o fungicida fludioxonil. A incidência de PRS não foi afetada, mas todos os PCT e o fludioxonil reduziram a severidade em relação à testemunha. A aplicação de produtos à base de Trichoderma spp. foi tão eficaz quanto o fludioxonil no manejo da PRS.

  6. Genome sequences of two Phytophthora species responsible for Sudden Oak Death and Soybean Root Rot provide novel insights into their evolutionary origins and mechanisms of pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tyler, Brett M.; Tripathi, Sucheta; Aerts, Andrea; Bensasson, Douda; Dehal, Paramvir; Dubchak, Inna; Garbelotto, Matteo; Gijzen, Mark; Huang, Wayne; Ivors, Kelly; Jiang, Rays; Kamoun, Sophien; Krampis, Konstantinos; Lamour, Kurt; McDonald, Hayes; Medina, Monica; Morris, Paul; Putnam, Nik; Rash, Sam; Salamov, Asaf; Smith, Brian; Smith, Joe; Terry, Astrid; Torto, Trudy; Grigoriev, Igor; Rokhsar, Daniel; Boore, Jeffrey

    2005-12-01

    The approximately 60 species of Phytophthora are all destructive pathogens, causing rots of roots, stems, leaves and fruits of a wide range of agriculturally and ornamentally important plants (1). Some species, such as P. cinnamomi, P. parasitica and P. cactorum, each attack hundreds of different plant host species, whereas others are more restricted. Some of the crops where Phytophthora infections cause the greatest financial losses include potato, soybean, tomato, alfalfa, tobacco, peppers, cucurbits, pineapple, strawberry, raspberry and a wide range of perennial tree crops, especially citrus, avocado, almonds, walnuts, apples and cocoa, and they also heavily affect the ornamental, nursery and forestry industries. The economic damage overall to crops in the United States by Phytophthora species is estimated in the tens of billions of dollars, including the costs of control measures, and worldwide it is many times this amount (1). In the northern midwest of the U.S., P. sojae causes $200 million in annual losses to soybean alone, and worldwide causes around $1-2 billion in losses per year. P. infestans infections resulted in the Irish potato famine last century and continues to be a difficult and worsening problem for potato and tomato growers worldwide, with worldwide costs estimated at $5 billion per year.

  7. Transient silencing mediated by in vitro synthesized double-stranded RNA indicates that PsCdc14 is required for sporangial development in a soybean root rot pathogen.

    Science.gov (United States)

    Zhao, Wei; Yang, Xinyu; Dong, Suomeng; Sheng, Yuting; Wang, Yuanchao; Zheng, Xiaobo

    2011-12-01

    In many eukaryotic organisms, Cdc14 phosphatase regulates multiple biological events during anaphase and is essential for mitosis. It has been shown that Cdc14 is required for sporulation in the potato blight pathogen Phytophthora infestans; however, the role that the Cdc14 homolog (PsCdc14) plays in the soil-borne soybean root rot pathogen P. sojae remains ambiguous. PsCdc14 is highly expressed in sporulation, zoospore, and cyst life stages, but not in vegetative mycelia and infection stages, suggesting that it contributes to asexual reproduction and thus the spread of the disease. Double-stranded RNA (dsRNA) mediates gene silencing, a post-transcriptional and highly conserved process in eukaryotes, involving specific gene silencing through degradation of target mRNA. We combined in vitro dsRNA synthesis and a polyethylene glycol-mediated transformation system to construct a dsRNA-mediated transient gene silencing system; and then performed a functional analysis of PsCdc14 in P. sojae. PsCdc14 mRNA was dramatically reduced in transformants after protoplasts were exposed in in vitro synthesized PsCdc14 dsRNA, resulting in low sporangial production and abnormal development in P. sojae silencing lines. Furthermore, dsRNA-mediated transient gene silencing could enable elucidation of P. sojae rapid gene function, facilitating our understanding of the development and pathogenicity mechanisms of this oomycete fungus.

  8. 台湾褐根病发生情况及研究进展%Research advances of brown root rot (Phellinus noxius) in Taiwan, China

    Institute of Scientific and Technical Information of China (English)

    林石明; 廖富荣; 陈红运; 陈青; 陈华忠

    2012-01-01

    褐根病菌是中国大陆的检疫性有害生物。褐根病是由有害木层孔菌(Phellinus noxius(Comer)Cunningham)引起经济作物、果树、景观名木古树和园林绿化等植物的毁灭性土传病害。近年来,在台湾的59科140多种植物上普遍发生并严重危害。本文综述了台湾在褐根病方面的研究进展,内容包括该病原菌的寄主、形态特征和生物学特性,病害发生发展规律和防治措施以及检测与鉴定方法。%Phellinus noxius is one of the quarantine pest of China mainland. It causes brown root rot of fruit and ornamental tree, which is a destructive disease of ancient and famous trees. P. noxius is a soil - borne pathogen. The disease is spreading among 59 families, more than 140 species of host plants these years in Taiwan. We expatiated recent research advances in Taiwan, China, including morphological and biological characteristics, spread model and control measurements and the detection & identification methods.

  9. Reação de cultivares de abacateiro à podridão de raízes Reaction of avocado cultivars to avocado root rot

    Directory of Open Access Journals (Sweden)

    Ciro Hideki Sumida

    2009-07-01

    Full Text Available As cultivares de abacateiro (Persea americana Mill 'Margarida', 'Fortuna' e 'Hass' têm muita importância econômica no mercado nacional e internacional. Em função disso, este trabalho teve como objetivo avaliar a reação dessas cultivares frente à Phytophthora cinnamomi Rands., agente causal da podridão das raízes. A inoculação do patógeno foi feita por meio de implantação de tecidos de raízes sintomáticas. Foram inoculadas quatro raízes em três árvores diferentes, uma de cada cultivar, em três pontos diferentes da raiz. Em cada cultivar, das quatro raízes, uma foi utilizada como testemunha, nas quais foram implantados tecidos sadios. A avaliação foi realizada aos 120 dias após a inoculação, observando-se as raízes externamente quanto à alteração da coloração e presença de estruturas de patógenos na região da superfície da casca nos pontos inoculados. Internamente, foram removidas as cascas para visualização das alterações a partir do ponto inoculado, sendo observadas alterações de coloração dos tecidos e realizada mensuração da extensão do escurecimento (lesão aparente. Nas extremidades das lesões foram retirados segmentos de raízes e implantados em meio de cultivo farinha de milho-ágar e incubados, para verificação da colonização na área sem escurecimento, ou seja, a colonização não- aparente. Das cultivares avaliadas, a 'Hass' foi a menos suscetível ao P. cinnamomi, quando comparada às cultivares 'Fortuna' e 'Margarida'. O patógeno P. cinnamomi pode apresentar desenvolvimento ou colonização nos tecidos radiculares além da área sintomática.Cultivars of the avocado (Persea americana Mill 'Margarida', 'Fortuna' and 'Geada' have importance in the national and international markets. The present paper had as objective to evaluate the reaction of such cultivars to Phytophthora cinanamomi Rands, the causal agent of avocado root rot. They were inoculated four roots in three different

  10. Effect of CO2 enhancement on beech (Fagus sylvatica L. seedling root rot due to Phytophthora plurivora and Phytophthora cactorum

    Directory of Open Access Journals (Sweden)

    Tkaczyk Miłosz

    2014-09-01

    Full Text Available Global climate change is associated with higher concentrations of atmospheric carbon dioxide (CO2. The ongoing changes are likely to have significant, direct or indirect effects on plant diseases caused by many biotic agents such as phytopathogenic fungi. This study results showed that increased CO2 concentration did not stimulate the growth of 1-year-old beech Fagus sylvatica L seedlings but it activated pathogenic Phytophthora species (P. plurivora and P. cactorum which caused significant reduction in the total number of fine roots as well as their length and area. The results of the greenhouse experiment indicated that pathogens once introduced into soil survived in pot soil, became periodically active (in sufficient water conditions and were able to damage beech fine roots. However, the trees mortality was not observed during the first year of experiment. DNA analyses performed on soil and beech tissue proved persistence of introduced Phytophthora isolates.

  11. Monitoring of Soft Fruit Mother Plantings Aimed at Control of Phytophthora fragariae, Causal Agent of Root Rot

    Directory of Open Access Journals (Sweden)

    Slobodan Milenković

    2006-12-01

    Full Text Available Phytophthora fragariae was first detected in the Republic of Serbia in 2002, and it has been included in A2 quarantine list of damaging organisms since 2003. The project titled ‘Monitoring of soft fruit mother plantings aimed at the control of Phytophthora fragariae, causal agent of root rot’ was realized over 2004 – 2005 aiming at determination of population rate of the pathogen and the control of raspberry planting material. Over that period, the total 388 samples were tested. Collected samples were analyzed by PCR. The presence of Phytophthora fragariae was detected in 156 samples.

  12. 土壤生境抑制烟草根黑腐病研究进展%Research Advance of Suppression Effect of Soil Habitat on Tobacco Black Root Rot

    Institute of Scientific and Technical Information of China (English)

    饶兴义; 霍沁建; 曹务栋; 张梦; 蒋卫

    2011-01-01

    Tobacco black root rot once resulting in great loss was a worldwide fungal disease. This paper gave a concise introduction on the outbreak of tobacco black root rot in our nation recent years, and the pathogenicbacteria, biological characteristics, infection and symptom of this disease, and then summarized the effects of soil habitat factors, included soil physi-chemical properties, soil nutrient status, root exudates and soil microorganism, on tobacco black root rot. At last, we raised some procedures, such as improving field management and cultivation strategies, reasonable fertilization and biocontrol, to ameliorate soil habitat and control the disease.%烟草根黑腐病是一种世界性真菌病,曾给各主要种烟国造成巨大损失.为此简述了近20年来烟草根黑腐病在中国各主要种烟省份爆发流行的状况,并对此病害的病原菌、生物学特性、侵染和病症特征加以介绍,总结了土壤理化性质、土壤养分状况、根系分泌物和土壤微生物等土壤生境因子对该病病原菌存活、侵染、病害爆发的影响,提出通过加强田间管理、改进栽培策略、合理施用肥料、引入生物防治等措施,以改善土壤生境为目标,抑制烟草根黑腐病爆发.

  13. Mapping of a Novel Race Specific Resistance Gene to Phytophthora Root Rot of Pepper (Capsicum annuum) Using Bulked Segregant Analysis Combined with Specific Length Amplified Fragment Sequencing Strategy.

    Science.gov (United States)

    Xu, Xiaomei; Chao, Juan; Cheng, Xueli; Wang, Rui; Sun, Baojuan; Wang, Hengming; Luo, Shaobo; Xu, Xiaowan; Wu, Tingquan; Li, Ying

    2016-01-01

    Phytophthora root rot caused by Phytophthora capsici (P. capsici) is a serious limitation to pepper production in Southern China, with high temperature and humidity. Mapping PRR resistance genes can provide linked DNA markers for breeding PRR resistant varieties by molecular marker-assisted selection (MAS). Two BC1 populations and an F2 population derived from a cross between P. capsici-resistant accession, Criollo de Morelos 334 (CM334) and P. capsici-susceptible accession, New Mexico Capsicum Accession 10399 (NMCA10399) were used to investigate the genetic characteristics of PRR resistance. PRR resistance to isolate Byl4 (race 3) was controlled by a single dominant gene, PhR10, that was mapped to an interval of 16.39Mb at the end of the long arm of chromosome 10. Integration of bulked segregant analysis (BSA) and Specific Length Amplified Fragment sequencing (SLAF-seq) provided an efficient genetic mapping strategy. Ten polymorphic Simple Sequence Repeat (SSR) markers were found within this region and used to screen the genotypes of 636 BC1 plants, delimiting PhR10 to a 2.57 Mb interval between markers P52-11-21 (1.5 cM away) and P52-11-41 (1.1 cM). A total of 163 genes were annotated within this region and 31 were predicted to be associated with disease resistance. PhR10 is a novel race specific gene for PRR, and this paper describes linked SSR markers suitable for marker-assisted selection of PRR resistant varieties, also laying a foundation for cloning the resistance gene.

  14. Characterization of Fusarium isolates from asparagus fields in southwestern Ontario and influence of soil organic amendments on Fusarium crown and root rot.

    Science.gov (United States)

    Borrego-Benjumea, Ana; Basallote-Ureba, María J; Melero-Vara, José M; Abbasi, Pervaiz A

    2014-04-01

    Fusarium crown and root rot (FCRR) of asparagus has a complex etiology with several soilborne Fusarium spp. as causal agents. Ninety-three Fusarium isolates, obtained from plant and soil samples collected from commercial asparagus fields in southwestern Ontario with a history of FCRR, were identified as Fusarium oxysporum (65.5%), F. proliferatum (18.3%), F. solani (6.4%), F. acuminatum (6.4%), and F. redolens (3.2%) based on morphological or cultural characteristics and polymerase chain reaction (PCR) analysis with species-specific primers. The intersimple-sequence repeat PCR analysis of the field isolates revealed considerable variability among the isolates belonging to different Fusarium spp. In the in vitro pathogenicity screening tests, 50% of the field isolates were pathogenic to asparagus, and 22% of the isolates caused the most severe symptoms on asparagus. The management of FCRR with soil organic amendments of pelleted poultry manure (PPM), olive residue compost, and fish emulsion was evaluated in a greenhouse using three asparagus cultivars of different susceptibility in soils infested with two of the pathogenic isolates (F. oxysporum Fo-1.5 and F. solani Fs-1.12). Lower FCRR symptom severity and higher plant weights were observed for most treatments on 'Jersey Giant' and 'Grande' but not on 'Mary Washington'. On all three cultivars, 1% PPM consistently reduced FCRR severity by 42 to 96% and increased plant weights by 77 to 152% compared with the Fusarium control treatment. Populations of Fusarium and total bacteria were enumerated after 1, 3, 7, and 14 days of soil amendment. In amended soils, the population of Fusarium spp. gradually decreased while the population of total culturable bacteria increased. These results indicate that soil organic amendments, especially PPM, can decrease disease severity and promote plant growth, possibly by decreasing pathogen population and enhancing bacterial activity in the soil.

  15. Identification of Biocontrol Bacteria against Soybean Root Rot with Biolog Automatic Microbiology Analysis System%拮抗大豆根腐病细菌的Biolog鉴定

    Institute of Scientific and Technical Information of China (English)

    许艳丽; 刘海龙; 李春杰; 潘凤娟; 李淑娴; 刘新晶

    2012-01-01

    In order to identify the systematic position of taxonomy of two biocontrol bacteria against soybean root rot. Traditional morphological identification and BIOLOG automatic microbiology analysis system were used to identify strain B021a and B04b. The results showed that similarity value of strain B021a with Vibrio tubiashii was 0. 634, possibility to 86% and genetic distance to 4.00,and similarity value of strain B04b with Pasteurella trehalosi was 0. 610,probability to 75% and genetic distance to 2. 77. Strain B021a was identified as Vibrio tubiashii and strain B04b as Pasteurella trehalosi by colony morphological propertie and BIOLOC analysis system.%为明确2株生防细菌的分类地位,采用传统形态学方法结合Biolog微生物自动分析系统,鉴定了大豆根腐病的2株生防细菌.结果表明,菌株B021a与塔式弧菌相似度值为0.634,可能性是86%,遗传距离为4.00.菌株B04b与海藻巴斯德菌相似度值为0.610,可能性是75%,遗传距离为2.77.综合形态学和Biolog鉴定结果,认为菌株B021a是塔式弧菌,菌株B04b是海藻巴斯德菌.

  16. Investigations on root and stem rot diseases of oat (Avena sativa L. with a special regard to temperature and rainfalls

    Directory of Open Access Journals (Sweden)

    Irena Kiecana

    2013-12-01

    Full Text Available Investigations were carried out in 1996-2000 in the Experimental Station of Cultivars Evaluation in Uhnin. Disease symptoms were recorded twice - in the seedling stage (18 in the Tottman's scale and in milk ripe stage (77 in the Tottman's scale of oat. The seedlings with root and sheath necrosis or plants with diseased stem base were obtained every year. The percentage of diseased seedlings ranged from 6,0 to 39,5. and percentage of older plants with necrotic stripes on lower internodes ranged from 11,5 to 5O,0.Results of mycological analysis of diseased plants showed that Fusarium spp., especially F.avenaceum and F.culmorum were isolated the most frequently, F.avenaceum was obtained in the seasons with different weather conditions. This indicates great tolerance of this fungus to temperature and humidity. In the seasons with high temperature F.culmorum was predominant. This species also can be tolerant to changing weather conditions. Warm and wet weather was favourable for oat infection by Bipolaris sorokiniana. Rhizoctonia solani was isolated from plants in milk ripe stage in each vegetation seasons. and from seedlings in years 1998 and 1999.

  17. Detection and characterization of broad-spectrum antipathogen activity of novel rhizobacterial isolates and suppression of Fusarium crown and root rot disease of tomato.

    Science.gov (United States)

    Zhang, L; Khabbaz, S E; Wang, A; Li, H; Abbasi, P A

    2015-03-01

    To detect and characterize broad-spectrum antipathogen activity of indigenous bacterial isolates obtained from potato soil and soya bean leaves for their potential to be developed as biofungicides to control soilborne diseases such as Fusarium crown and root rot of tomato (FCRR) caused by Fusarium oxysporum f. sp. radicis-lycopersici (Forl). Thirteen bacterial isolates (Bacillus amyloliquefaciens (four isolates), Paenibacillus polymyxa (three isolates), Pseudomonas chlororaphis (two isolates), Pseudomonas fluorescens (two isolates), Bacillus subtilis (one isolate) and Pseudomonas sp. (one isolate)) or their volatiles showed antagonistic activity against most of the 10 plant pathogens in plate assays. Cell-free culture filtrates (CF) of five isolates or 1-butanol extracts of CFs also inhibited the growth of most pathogen mycelia in plate assays. PCR analysis confirmed the presence of most antibiotic biosynthetic genes such as phlD, phzFA, prnD and pltC in most Pseudomonas isolates and bmyB, bacA, ituD, srfAA and fenD in most Bacillus isolates. These bacterial isolates varied in the production of hydrogen cyanide (HCN), siderophores, β-1,3-glucanases, chitinases, proteases, indole-3-acetic acid, salicylic acid, and for nitrogen fixation and phosphate solubilization. Gas chromatography-mass spectrometry analysis identified 10 volatile compounds from 10 isolates and 18 compounds from 1-butanol extracts of CFs of five isolates. Application of irradiated peat formulation of six isolates to tomato roots prior to transplanting in a Forl-infested potting mix and field soil provided protection of tomato plants from FCRR disease and enhanced plant growth under greenhouse conditions. Five of the 13 indigenous bacterial isolates were antagonistic to eight plant pathogens, both in vitro and in vivo. Antagonistic and plant-growth promotion activities of these isolates might be related to the production of several types of antibiotics, lytic enzymes, phytohormones, secondary

  18. 甘肃渭源蒙古黄芪根腐病病原菌的分离与鉴定%Isolation and identification of the pathogens causing Astragalus membranaceus var.mongholicus root rot in Weiyuan of Gansu Province

    Institute of Scientific and Technical Information of China (English)

    陈垣; 朱蕾; 郭凤霞; 武志江

    2011-01-01

    Root rot is one of the limitations of sustainable Astragalus membranaceus var. Mongholicus production. Six kinds of fungi were isolated from diseased plant samples with root rot symptom in Weiyuan county of Gansu Province. Based on pathogenicity tests, the major pathogens were Fusarium oxysporum and F. Solani, with the isolation percentage of 15. 8% -38. 1% and 25. 0%-42. 1% respectively at different growth stages. The incidence of root rot after inoculation of pathogens on goring seedling radicles was significantly higher than that on non-goring radicles. F. Oxysporum was showed to have a strong pathogenicity. All the results indicated that the climate, soil condition and seedlings, healthy state were contributory factors for root rot disease. It is suggested that healthy plant seedlings without wound under the standard operation is important for controlling A. Membranaceus var. Mongholicus root rot.%黄芪是豆科黄芪属蒙古黄芪[Astragalus membranaceus(Fisch.)Bge.var.mongholicus(Bge.)Hsiao]或膜荚黄芪[A membranceus(Fisch.)Bge.]的干燥根,主要成分有皂苷类、黄酮类、多糖及其它成分.具有补气固表、利尿托毒、排脓、敛疮生肌之功效[1].黄芪为多年生药用植物,野生资源贫乏,需求量大,现主要人工种植.蒙古黄芪原产于山西、内蒙、河北、陕西和甘肃等地.甘肃陇西、渭源、临洮和岷县等地种植的蒙古黄芪因品质优、产量高已成为我国主要的道地黄芪产区.然而,近几年根腐病(root rot)普遍发生,感病后轻者根部表皮粗糙(占35%~92%),重者呈褐色腐朽状.经研究,其致病菌有尖孢镰刀菌(Fusarium oxysporum Schlecht.)和腐皮镰孢菌(F.solani (Mart.)Sacc)[2].Luo等[3]曾提出一些防治措施,这对黄芪根腐病的发生与综防提供了一定参考,但由于对黄芪根腐病病原菌缺乏系统研究,因此,开展甘肃道地产区蒙古黄芪根腐病病原菌的分离和鉴定对进一步认识和防治该病具有重要意义.

  19. Jasmonic acid and salicylic acid inhibit growth of three sugarbeet storage rot pathogens

    Science.gov (United States)

    Storage rots contribute to postharvest losses by consuming sucrose and increasing carbohydrate impurities that increase sugar loss to molasses during processing. They also increase root respiration rate, which causes additional sucrose loss and contributes to pile warming. Currently, storage rots ...

  20. Endophytic bacteria from Piper tuberculatum Jacq.: isolation, molecular characterization, and in vitro screening for the control of Fusarium solani f. sp piperis, the causal agent of root rot disease in black pepper (Piper nigrum L.).

    Science.gov (United States)

    Nascimento, S B; Lima, A M; Borges, B N; de Souza, C R B

    2015-07-06

    Endophytic bacteria have been found to colonize internal tissues in many different plants, where they can have several beneficial effects, including defense against pathogens. In this study, we aimed to identify endophytic bacteria associated with roots of the tropical piperaceae Piper tuberculatum, which is known for its resistance to infection by Fusarium solani f. sp piperis, the causal agent of black pepper (Piper nigrum) root rot disease in the Amazon region. Based on 16S rRNA gene sequence analysis, we isolated endophytes belonging to 13 genera: Bacillus, Paenibacillus, Pseudomonas, Enterobacter, Rhizobium, Sinorhizobium, Agrobacterium, Ralstonia, Serratia, Cupriavidus, Mitsuaria, Pantoea, and Staphylococcus. The results showed that 56.52% of isolates were associated with the phylum Proteobacteria, which comprised α, β, and γ classes. Other bacteria were related to the phylum Firmicutes, including Bacillus, which was the most abundant genus among all isolates. Antagonistic assays revealed that Pt12 and Pt13 isolates, identified as Pseudomonas putida and Pseudomonas sp, respectively, were able to inhibit F. solani f. sp piperis growth in vitro. We describe, for the first time, the molecular identification of 23 endophytic bacteria from P. tuberculatum, among which two Pseudomonas species have the potential to control the pathogen responsible for root rot disease in black pepper in the Amazon region.

  1. Evaluation of microbial products for the control of zucchini foot and root rot caused by Fusarium solani f. sp. cucurbitae race 1

    Directory of Open Access Journals (Sweden)

    Roberta ROBERTI

    2012-09-01

    for an effective management of zucchini Fusarium foot and root rot through rhizosphere competence and several mechanisms exerted by their microbial ingredients.

  2. 甘肃高寒阴湿区豌豆根腐镰刀菌种群及致病性研究%Fusarium Population and Pathogenicity of Pea Root Rot in the Cold and Humid Regions of Gansu Province

    Institute of Scientific and Technical Information of China (English)

    刘小娟; 侯思雯; 杨晓明; 李敏权

    2012-01-01

    甘肃省高寒阴湿区豌豆镰刀菌根腐病的病原有5种,即茄病镰刀菌[ Fusarium solani ( Mart.) Sacc]、茄病镰刀菌蓝色变种(Fusarium solani var.coeruleum)、半裸镰刀菌(Fusarium semitectum)、单隔镰刀菌(Fusarium dimerum)、拟丝孢镰刀菌(Fusarium trichothecioides).茄病镰刀菌致病性最强,拟丝孢镰刀菌和茄病镰刀菌蓝色变种次之,半裸镰刀菌和单隔镰刀菌的致病性较弱.其中半裸镰刀菌、单隔镰刀菌、拟丝孢镰刀菌是中国豌豆病原菌上的新纪录.%The pathogen of pea Fusarium root rot in the cold and humid regions of Gansu were Fusarium solani (Mart. ) Sacc., Fusarium solani var. Coeruleum,, Fusarium semitectum ? Fusarium dimerum and Fusarium trichothe-cioides. The most pathogeniciry pathogen was F. Solani, while F. Trichothecioides, and F. Solani var. Coeruleum were the second;however F. Semitectum and F. Dimerum were the least pathogenicity pathogens. F. semitectumNF. Dime-rum ^F. Trichothecioides were new recorded on pea Fusarium root rot in China.

  3. 豇豆根腐病病原分离鉴定及其核糖体rDNA-ITS序列分析%Pathogeny Isolation and Identification of Cowpea Root Rot Disease and Sequencing of Ribosomal rDNA-ITS

    Institute of Scientific and Technical Information of China (English)

    吴仁锋; 杨绍丽; 万鹏; 黄薇

    2011-01-01

    The fungal isolate JGF from cowpea root rot disease, which were collected from Wuhan, were studied morphologically and molecularly. The results showed that the isolate JGF were morphological Fusarium solani Schl. The rDNA-ITS genes of isolate JGF were amplified and sequenced. Based on the Blast search and the alignment analysis in GenBank database combined with morphological characters, the pathogen of cowpea root rot disease was identified as Fusarium solani Schl.%采用形态学及分子生物学的方法对采集自武汉的豇豆根腐病分离物进行形态学和分子生物学鉴定.结果表明,菌株JGF形态学上为茄腐皮镰孢菌;对JGF菌株的核糖体RNA基因内转录间隔区(rDNA-ITS)进行了PCR扩增和序列测定,并在GenBank中进行了Blast搜索和比对分析,根据rDNA-ITS序列分析结果结合豇豆病株症状和病菌的形态学特征,认为武汉地区豇豆根腐病的病原菌为茄腐皮镰孢菌(Fusarium solani Schl.)

  4. 烟草根黑腐病菌致病力分化及品种抗性差异研究%Pathogenicity differentiation of Thielaviopsis basicola and resistance difference of tobacco against black root rot

    Institute of Scientific and Technical Information of China (English)

    窦彦霞; 李兰; 彭雄; 肖崇刚; 周常勇

    2012-01-01

    Thielaviopsis basicola (Berk,et Br. ) Ferr. causing tobacco black root rot were isolated with modified carrot disks from 5 provinces of China, and their pathogenicity differentiation were studied by root cutting inoculation method. In the study, the disease resistances of 7 main tobacco cultivars against different T. basicola isolates were also evaluated. A total of 14 isolates of T. basicola were obtained, and their pathogenicity showed significant difference. The disease index of 14 isolates ranged from 29.2 to 62.5, in which 4 isolates showed high pathogenicity, 10 isolates were at moderate level, and no weak pathogenic isolate was found. The disease resistances were significantly different among the 7 cultivars when different cultivars were inoculated by a certain T. basicola isolates. The disease resistance changed from resistant, moderate resistant to susceptible and highly susceptible. The resistance of Guiyan 4, Qinyan 96 and Zhongyan 100 were higher than those of other tested cultivars.

  5. 大麦种质资源苗期根腐病抗性鉴定%Assessment of Root Rot Resistance in a Collection of Barley Germplasm at the Seedling Stage

    Institute of Scientific and Technical Information of China (English)

    吕二锁; 张凤英; 蔺瑞明; 包海柱; 刘志萍

    2015-01-01

    试验采用孢子悬浮液喷雾接种法,对国内外205份大麦种质资源材料进行实验室苗期根腐病抗性筛选、鉴定。结果表明,有11份材料高抗根腐病,35份材料中抗根腐病,156份材料中感或高感根腐病;以发病严重度为分析变量做品种抗病性聚类分析,取欧式距离为2.14时,品种抗病性可分为两大类,第一类抗病材料(包括高抗与中抗)总共有46份,占供试鉴定材料的22.44%;第二类感病材料(包括中感与高感)总共有156份,占供试鉴定材料的77.09%;获得的抗病材料可作为抗病育种亲本材料,为丰富和拓展我国大麦抗病育种种质资源奠定基础。%This study assessed root rot resistance in a collection of 205 samples of barley germplasm originating domestically and inter-nationally using the method of sprays for inoculating the spore suspension of the pathogen. As a result, 11 and 35 barley samples had high and medium resistance, respectively, to root rot disease, while 156 samples were moderately or highly susceptible to the disease. A clustering analysis was conducted using disease severity as the variable with Euclidean distance of 2. 14, which divided these samples into two groups based on their disease resistance. The first group was considered disease-resistant materials, which comprised 46 sam-ples with medium or high resistance to root rot disease, accounting for 22. 44% of all collected samples. The second group was consid-ered disease-susceptible materials, which consisted of 156 samples with moderate or high susceptibility to the disease, constituting 77. 09% of all samples. The samples resistant to the disease can be used as parental materials for breeding disease-resistant barley varieties. Therefore, the current study laid a foundation for enriching disease-resistant barley germplasm resources in China.

  6. Comparison of Four Kinds of Seed Coating Agents on Root Rot Control Efficiency of Soybean%4种种衣剂对大豆根腐病的防效比较

    Institute of Scientific and Technical Information of China (English)

    米娜瓦尔·艾买提; 刘利群

    2013-01-01

    [目的]研究4种种衣剂防治大豆根腐病的综合效应.[方法]以大豆主栽品种阿豆1号作为试材,将大豆种子采用4种种衣剂处理后播种在根腐病严重的病土中,测定其出苗率、株高、病株率、死亡率、病情指数等指标.[结果]在根腐病严重的土壤条件下,4种种衣剂处理中,除处理Ⅰ和Ⅳ的出苗率显著低于对照以外,处理Ⅱ和Ⅲ均保持与对照相同的水平;虽然种衣剂处理后,大豆须根数量有一定程度的减少,但其株高有所提高,病株率、死亡率和病情指数有不同程度的下降.[结论]4种种衣剂对大豆根腐病的防病效果有差异,效果大小顺序依次为36.8%阿维菌素·多菌灵·福美双(ADF)悬浮种衣剂(Ⅱ)、40%卫福悬浮种衣剂(Ⅲ)、35% kdf悬浮种衣剂(Ⅰ)、18%福克悬浮种衣剂(Ⅳ).%[Objective] To study the combined prevention effect of four kind of seed coating agent on soybean root rot.[Method] With soybean cultivar "Adou No.1" as test material,after soybean seeds were coated by four kinds of seed coating agent,sown it in serious root rot disease soil,and measured their emergence rate,plant height,diseased plant rate,mortality plant rate,disease index and disease prevention efficiency.[Result] Under serious root rot soil conditions,among four kind of seed coating agent,except the Ⅰ and Ⅳ has a significantly lower emergence rate compared with the control,treatment Ⅱ and Ⅲ kept the same level emergence rate compared with the control.Although there were some degree reduce on the fibrous root number and nodule number of soybean after treated with four seed coating agent,but the diseased plant rate,mortality plant rate,disease index decreased in some degrees.[Conclusion] Some differences were occurred on the disease prevention efficiency of four seed coating agents on soybean root rot disease,the order:36.8% aweijunsu duojunling fumeishuang (ADF) seed coating agent (Ⅱ) >40% fuwei seed

  7. Effect of composts on microbial dynamics and activity, dry root rot severity and seed yield of cowpea in the Indian arid region

    Directory of Open Access Journals (Sweden)

    Meenu BAREJA

    2011-01-01

    Full Text Available Nutrient-deficient sandy soil, having poor moisture retention, favors  Macrophomina phaseolina, a soil-borne plant pathogen, occurring in severe form on many important crops grown in the Indian arid region. In a 2-year field experiment, five composts (4 ton/ha prepared from residues of Calotropis procera, Prosopis juliflora, Azadirachta indica, Acacia nilotica, and on-farm weeds were tested on cowpea (Vigna unguiculata to determine their effectiveness in limiting the  severity of charcoal rot caused by M. phaseolina in relation to the microbial population dynamics, microbial activity and the seed yield of cowpea.  In general, compost-amended plots retained 8.9% higher moisture than unamended plots. The microbial population increased in amended plots during the crop season. Populations of total fungi and actinomycetes were heighest in Calotropis compost-amended soil, while total bacteria were maximum in weed- compost amended soil. Microbial activity in amended plots was  26.3% higher than in unamended plots. Among trace elements,  uptake of Zn, Mn, Fe and Cu was  heighest  in plants grown in weed-compost amended soil followed by A. nilotica compost-amended soil. Soil amendment with the composts significantly reduced  plant mortality due to charcoal rot. The lowest mortality was recorded in plants amended with A. nilotica compost (5.5% followed by P. juliflora compost (5.8, while the  highest plant mortality (11.5% from charcoal rot occurred in the unamended control on the basis of the pooled average of two years. There was a significant inverse correlation between microbial activity and charcoal rot incidence in cowpea at 20 days after planting. Composts also had a beneficial effect on yield, with a 28.3% increase in seed yield in P. juliflora compost-amended plots. These results suggest that in resource-deficient farming , certain on-farm wastes can be effectively utilized for managing soil-borne pathogens, as well as  for

  8. 不同类型生物农药对大豆疫霉根腐病的防治效果%Control Efficiency of Different Biopesticides on Soybean Phytophthora Root Rot

    Institute of Scientific and Technical Information of China (English)

    申宏波; 姚文秋; 于永梅; 丁俊杰; 顾鑫; 杨晓贺; 赵海红; 文景芝

    2011-01-01

    对Harpins蛋白、B5、G3、嗜线虫杆菌、蜡介轮支菌菌土、“818”发酵液和恩益碧种衣剂7种不同类型生物农药对大豆疫霉根腐病的防治效果进行了比较,结果表明:以南京农业大学提供的Harpins蛋白在使用浓度为45 mg·L-l时防治效果最好,大豆疫霉根腐病的平均发病率仅为0.12%,防治效果达到75%,平均产量比对照增加7%.其次是中国农业科学院生物防治所提供的“818”发酵液,防治效果达到58.3%.45 mg· L-1 Harpins蛋白、“818”发酵液防效与对照的差异均达极显著水平.%The control effects of seven different types of biological pesticide on soybean Phytopktkora root rot were compared in this research. The incidence and prevention efficiency of phytophthora root rat, as well as soybean yield were determined. The results showed that 45 mg·L-1 Harpins protein from Nanjing Agricultural University had the best control effect,the average incidence of Phytophthora root rot of was 0.12% ,the prevention effect reached 75% and average yield was 7% higher than CK. The second was "818" fermentation liquid provided by the Chinese Academy of Agricultural Sciences, the prevention effect reached 58.3%. The control effect of 45 mg·L-1 Hatpins protein and "818" fermentation liquid were extremely significant different with CK.

  9. Biocontrol of Isatis indigotica root rot by the bacterial strain Bs-0728%拮抗细菌Bs-0728对板蓝根根腐病的防治作用

    Institute of Scientific and Technical Information of China (English)

    高琳娜; 曹克强; 段英姿; 王树桐

    2011-01-01

    [Objective] To screen effective antagonistic bacterium to Isatis indigotica root rot. [Method] Dural culture was conducted to test the antagonism of 201 bacterial strains isolated from 137 /. Indigotica rhizosphere soil samples. [Result] The bacterial strain Bs-0728 showed the highest antagonistic effect against the major /saris root rot pathogen Fusarium solani. Bs-0728 was highly inhibitory to F. Solani by making the mycelia swollen and curly. Treated with fermentation broth of Bs-0728 in field trials, the disease control efficacy reached 72. 97%, and the yield of /. Indigotica root increased by 86.26% compared with the untreated control. Identification by morphological observations, physiological and biochemical determination, and 16S rDNA sequence analysis showed that the strain belonged to Bacillus subtilis. [Conclusion] The stain Bs-0728 is a promising biological strain for application.%[目的]筛选对板蓝根根腐病有较强拮抗作用的生防菌株.[方法]采用平板对峙法对137个板蓝根根际土壤样本中分离到的201株拮抗细菌进行测试.[结果]筛选出1个对板蓝根根腐病菌有强烈抑制作用的菌株Bs0728.结合显微镜观察确定Bs-0728菌株对板蓝根根腐病的主要致病菌茄腐镰刀菌(Fusarium solani)菌丝生长有较强的抑制作用,导致菌丝生长畸形,弯曲,部分细胞膨大.田间试验结果表明,Bs-0728的发酵液田间防效达72.97%,且增产86.26%.经形态观察、生理生化反应及16S rDNA序列分析,初步将此拮抗细菌鉴定为枯草芽胞杆菌Bacillus subtilis.[结论]枯草芽孢杆菌Bs-0728菌株是一株很有应用前景的生防菌株.

  10. Effect of phosphorus and the arbuscular mycorrhizal fungus Glomus intraradices on disease severity of root rot of peas (Pisum sativum) caused by Aphanomyces euteiches

    DEFF Research Database (Denmark)

    Bødker, Lars; Kjøller, Rasmus; Rosendahl, Søren

    1998-01-01

    The effects of inorganic phosphate levels and the presence of arbuscular mycorrhiza on disease severity of Aphanomyces euteiches in pea roots were studied. Disease severity on roots and epicotyl as well as the oospore number within infected root tissue were correlated with the phosphorus (P) level...... in the growth medium. The arbuscular mycorrhizal fungus Glomus intraradices increased P uptake and the P concentration in the plant but reduced disease development in peas. Polyacrylamide gel electrophoresis followed by densitometry of glucose-6-phosphate dehydrogenase specific to A.euteiches was used...

  11. Fungi Diversity of Rhizosphere Soil with Loquat Root Rot Disease in Yunnan Province%云南蒙自枇杷根腐病植株根际土壤真菌多样性研究

    Institute of Scientific and Technical Information of China (English)

    杨若鹏; 郑肖兰; 田学军; 李建平; 鲁海菊

    2012-01-01

    摘要摸清蒙自枇杷根腐病病株根际土壤真菌区系分布.为有效可持续防控枇杷根腐病提供理论依据。采用五点取样法采集土壤样品,稀释平板法在PDA培养基上分离纯化,获得114株枇杷根腐病病株根际土壤真菌,经显微镜形态鉴定。109株真菌鉴定为以下24种: A bs idia corymbifera, A bsidia cylindrospora, A bsidia spinosa,Acremonium cerealis, Acremonium murorum, Aspergillus niger, Cladosporium cladosporioides, Colletotrichum dematium, Fusarium flocciferum, Mucor circineUoides f. janssenii, Mucor circinelloides f. wsitanicus, PeniciUium atrovenetum, Penicillium canescens, PeniciUium chrysogenum, Penicillium corylophilum, Penicillium daleae, Penicillium digitatum, Penicillium nigricans, Penicillium oxalicum, Penicillium saceulum, Penicillium variabile,Pythium intermedium, Trichoderma strigosum, Verticillium fungicola,分属于11个属.其中青霉属(Penicillium)是优势属,另外5株真菌属于担子菌。%To establish the species and distribution of fungi of Loquat rhizosphere soil which had rot root disease at Mengzi in Yunnan Province and to provide theoretical basis for efficient control to disease of the root rot; Soil specimen were collected with the 5-point method. The fungi strains were isolated by the plate of gradient dilution with PDA medium. The strains were identified by morphology with microscope. The strains respectively belong to A bsidia corymbifera, A bsidia cylindrospora, A bsidia spinosa, A cremonium cerealis, Acremonium murorum, Aspergillus niger, Cladosporium cladosporioides, Colletotrichum dematium, Fusarium flocciferum, Mucor circinelloides f. janssenii, Mucor circineUoides f. wsitanicus, Penicillium atrovenetum, Penicillium canescens, Penicillium chrysogenum, Penicillium corylophilum, PeniciUium daleae, Penicillium digitatum, Penicillium nigricans, PeniciUium oxalicum, Penicillium saceulum, PeniciUium variabile, Pythium intermedium, Trichoderma strigosum

  12. Prediction of potential geographic distribution of strawberry red stele root rot (Phytophthora fragariae Hickman) in China using MAXENT%基于MAXENT的草莓疫霉红心病在中国的适生性分析

    Institute of Scientific and Technical Information of China (English)

    张静秋; 王振华; 龚国祥; 娄少之; 郑作良; 陈克

    2014-01-01

    Strawberry red stele root rot is a kind of destructive disease, it is important to prevent the expansion of the disease in China. Based on MAXENT model, we predicted the potential geographic distribution in China and analyzed the bioclimatic variables of the disease. The results showed that the main risky areas distributed in Yangtze River region, where there is also the main strawberry producing areas. Mean temperature of the coldest quarter, precipitation of the driest quarter and annual mean temperature were the main bioclimatic factors in the distribution of disease.%草莓疫霉红心病是草莓的重要病害,预防和控制该病害在中国扩展蔓延十分重要。本研究利用 MAXENT 生态位模型预测草莓疫霉红心病在中国的适生区并分析影响病害适生的环境变量,结果表明长江中下游流域草莓主产区是该病害的适生区。最冷季节平均温度、最干季度降水量和年平均温度是影响病害发展的主要因素。

  13. Role of the HaHOG1 MAP kinase in response of the conifer root and butt rot pathogen (heterobasidion annosum to osmotic and oxidative stress [corrected].

    Directory of Open Access Journals (Sweden)

    Tommaso Raffaello

    Full Text Available The basidiomycete Heterobasidion annosum (Fr. Bref. s.l. is a filamentous white rot fungus, considered to be the most economically important pathogen of conifer trees. Despite the severity of the tree infection, very little is known about the molecular and biochemical aspects related to adaptation to abiotic stresses. In this study, the osmotic and oxidative tolerance as well as the role of the HaHOG1 Mitogen Activated Protein Kinase (MAPK gene were investigated. The transcript levels of the yeast orthologues GPD1, HSP78, STL1, GRE2 and the ATPase pumps ENA1, PMR1, PMC1 known to have an important role in osmotolerance were also quantified under salt osmotic conditions. The HaHOG1 gene was used for a heterologous expression and functional study in the Saccharomyces cerevisiae Δhog1 strain. Moreover, the phosphorylation level of HaHog1p was studied under salt osmotic and oxidative stress. The result showed that H. annosum displayed a decreased growth when exposed to an increased concentration of osmotic and oxidative stressors. GPD1, HSP78, STL1 and GRE2 showed an induction already at 10 min after exposure to salt stress. Among the ATPase pumps studied, PMC1 was highly induced when the fungus was exposed to 0.2 M CaCl₂ for 60 min. The heterologous expression of the HaHOG1 sequence in yeast confirmed that the gene is able to restore the osmotolerance and oxidative tolerance in the S. cerevisiae hog1Δ mutant strain. The HaHog1p was strongly phosphorylated in the presence of NaCl, KCl, H₂O₂ but not in the presence of CaCl₂ and MgCl₂. The GFP-HaHog1p fusion protein accumulated in the nuclei of the S. cerevisiae hog1Δ cells when exposed to high osmotic conditions but not under oxidative stress. These results provide the first insights about the response of H. annosum to osmotic and oxidative stress and elucidate the role of the HaHOG1 gene in such conditions.

  14. Effects of cell suspension and cell·free culture filtrate of Pseudomonas aeruginosa in the control of root rot-root kont disease complex of tomato (Lycopersicon esculentum Mill.

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    I. A. Siddiqui

    2013-12-01

    Full Text Available The plant growth-promoting rhizobacterium Pseudomonas aeruginosa strain IE-6 was tested for antagonistic activity towards Meloidogyne javanica, the root-knot nematode and soilbome root-infecting fungi viz., Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani under laboratory and greenhouse conditions. Cell-free culture filtrate of the bacterium caused significant reduction in egg hatching of M.javanica and inhibited radial growth of fungi in vitro. Cell-free culture filtrate also caused lyses in mycelium of F.solani. Under greenhouse conditions, soil drenches with the aqueous cell suspension or cell-free culture resulted in a considerable reduction in nematode population densities in soil and subsequent root-knot development due to M.javanica. In addition to nematode control, rhizobacterium application also inhibited root-infection caused by soilborne root~infecting fungi with significant enhancement of growth of tomato seedlings.

  15. Heterobasidion annosum root and butt rot of Norway spruce, Picea abies: Colonization by the fungus and its impact on tree growth

    Energy Technology Data Exchange (ETDEWEB)

    Bendz-Hellgren, M. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology

    1997-12-31

    Diameter growth losses associated with decay were quantified on a nationwide scale, and volume growth losses were measured in two stands. Diameter growth losses were 8-10% during a 5-year period in the nationwide study and 23% in one of the stands, whereas in the other stand, no volume losses could be attributed to decay. The effects of stump moisture content, temperature and time elapsed between felling and inoculation on the establishment of H. annosum spore infections in stumps were investigated among stumps resulting from thinnings and clear-cuttings. Furthermore, inoculations with H. annosum conidia were made between 0 hours and 4 weeks after thinning. The incidence of stump infections was lower on clear-cut areas than in thinned stands, but high enough to warrant stump treatment on clear-cuttings. A positive relation was found between heartwood moisture content and the proportion of heartwood infected, whereas the opposite relation was found for sapwood. The establishment of new conidiospore infections decreased with time, and it appeared that stumps were no longer susceptible to infection after 3 weeks had elapsed since felling. Roots of stumps and trees on forest land or former arable land were inoculated with H. annosum treated sawdust. The growth rate of H. annosum in roots of stumps was 25 cm/year, corresponding to 2.5 to 3 times the growth rate in tree roots. Previous land use did not affect the fungal rate of spread. Also, the average initial spread rate of H. annosum in naturally infected Norway spruce stems was estimated at 30 cm/year 156 refs, 9 figs

  16. INFLUÊNCIA DO PREPARO DE SOLO E DA ROTAÇÃO DE CULTURAS NA SEVERIDADE DE PODRIDÕES RADICULARES NO FEIJOEIRO COMUM EFFECTS OF SOIL TILLAGE SYSTEM AND CROP ROTATION ON DRY BEAN ROOT ROT SEVERITY

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    Pedro Marques da Silveira

    2007-09-01

    Full Text Available

    As podridões radiculares do feijoeiro são causadas pelos fungos Rhizoctonia solani Kühn e Fusarium solani f. sp. phaseoli Snyd. & Hans. Neste trabalho testou-se a combinação dos fatores preparo de solo e rotação de culturas, além de se avaliarem seus efeitos sobre as podridões radiculares do feijoeiro. Os tipos de preparo de solo consistiram em: arado+grade (P1, arado (P2, grade (P3 e plantio direto (P4. As rotações de culturas foram: arroz-feijão (R1, milho-feijão (R2, arroz/calopogônio (Calopogonium muconoides-feijão (R3 e milho-feijão-milho-feijão-arroz-feijão (R4. A severidade de F. solani f. sp. phaseoli, avaliada aos 25 dias após o plantio, apresentou interação significativa, sendo a maior severidade encontrada na combinação da rotação R3 com o preparo de solo P1, e a menor severidade, na combinação da rotação R2 com o preparo de solo P3. Diferenças estatísticas ocorreram na severidade da doença provocada por R. solani. O preparo de solo P3 apresentou maior severidade que P4, e, entre as rotações, R3 apresentou a maior severidade da doença.

    PALAVRAS-CHAVE: Rhizoctonia solani; Fusarium solani f. sp. phaseoli; práticas culturais; fungos.

    Dry bean root rot is caused by the fungi Rhizoctonia solani Kühn and Fusarium solani f. sp. phaseoli Snyd. & Hans.The effects of the interaction between soil tillage systems andcrop rotation on the severity of root rot was tested. The soiltillage systems consisted of plough+harrow (P1, plough (P2,harrow (P3 and no tillage (P4 and the crop rotation treatmentswere rice-bean (R1, corn-bean (R2, rice/Calopogonium muconoides-bean (R3 and corn

  17. Indução de resistência do mamoeiro à podridão radicular por indutores bióticos e abióticos Resistance induction to root rot in papaya by biotic and abiotic elicitors

    Directory of Open Access Journals (Sweden)

    Giltembergue Macedo Tavares

    2009-11-01

    Full Text Available O objetivo deste trabalho foi avaliar o potencial do uso de indutores de resistência bióticos e abióticos na redução da podridão radicular em mamoeiro. Mudas de mamoeiro foram pulverizadas com os fungicidas fosetil-Al, metalaxil e Mancozeb (2 g L-1, com os indutores abióticos fosfito de potássio (2,5 e 5 mL L-1, ácido salicílico 0,15 e 0,30%, Reforce (indutor comercial + ácido salicílico a 5%, acibenzolar-S-metil (ASM (0,15 e 0,30 g L-1, e com o indutor biótico Saccharomyces cerevisiae (3 e 6 mL L-1, três e seis dias antes da pulverização de 1 mL de suspensão de 10(5 zoósporos mL-1 de Phytophthora palmivora. Todos os tratamentos tiveram efeito no controle da podridão de raízes em relação à testemunha, com exceção do Reforce + ácido salicílico a 5% (3 mL L-1, seis dias antes da inoculação. Os tratamentos com ASM, com exceção da dosagem 0,15 g L-1 seis dias antes da inoculação, apresentaram resultados similares aos dos fungicidas metalaxil e Mancozeb. Plantas pulverizadas com ASM apresentaram aumento de atividade da peroxidase e beta-1,3-glucanase e maior concentração de lignina que a testemunha. No entanto, esses tratamentos não tiverem efeito sobre a atividade da quitinase. O ASM é um potencial indutor de resistência a P. palmivora em mamoeiro.The objective of this work was to evaluate the potential use of biotic and abiotic elicitors of resistance in the reduction of root rot in papaya. Papaya seedlings were sprayed with the fosetil-Al and metalaxyl and Mancozeb (2 g L-1 fungicides, with the potassium phosphite (2.5 and 5 mL L-1, salicylic acid 0.15 e 0.30%, Reforce (commercial product + salicylic acid 5%, acibenzolar-S-methyl (ASM (0.15 and 0.30 g L-1 abiotic elicitors, and with the Saccharomyces cerevisiae (3 and 6 mL L-1 biotic elicitor, applied three and six days before the inoculation with 1 mL of 10(5 zoospores mL-1 suspension of Phytophthora palmivora. All treatments were effective in controlling

  18. BvGLP1过表达增强了转基因小麦对根腐病的抗性%Expression of BvGLP1 in Transgenic Wheat Enhances Resistance to Common Root Rot

    Institute of Scientific and Technical Information of China (English)

    党良; 宿振起; 叶兴国; 徐惠君; 李钊; 邵艳军; 张增艳

    2013-01-01

    BvGLP1 is a kind of germin-like protein (GLP) from sugar beet. GLP catalyzes the oxidation of oxalic acid to produce hydrogen peroxide that induces plant defense response to pathogen and results in enhanced-resistance. The open-reading-frame sequence of BvGLP1 was synthesized and used to construct a BvGLP1 expression vector pA20-RSS1P::BvGLP1. In the vector, the expression of BvGLP1 was controlled by rice sucrose synthase-1 promoter (RSS1P). BvGLP1 was introduced into wheat vari-ety Yangmai 18 through bombardment. The presence and expression of BvGLP1 in T0 to T3 transgenic wheat plants were charac-terized by PCR, RT-PCR, and QPCR analyses. The common root rot and sharp eyespot disease tests on BvGLP1 transgenic wheat plants following artificial inoculation with the pathogens revealed that the expression of BvGLP1 in five transgenic wheat lines significantly enhanced resistance to common root rot.%  类萌发素蛋白(germin-like protein, GLP)是一类含有cupins结构域的糖蛋白,在植物基础抗性等方面起着重要作用.本研究人工合成了甜菜GLP基因BvGLP1,并利用基因重组技术构建了受韧皮部特异表达启动子RSS1P驱动的BvGLP1基因单子叶植物表达载体pA20-RSS1P::BvGLP1.通过基因枪介导法将其转入小麦品种扬麦18中,对转基因扬麦18的T0至T3代植株中BvGLP1进行了PCR、半定量RT-PCR和荧光定量QPCR检测,并对转基因小麦进行根腐病和纹枯病抗性鉴定.结果表明, BvGLP1已转入转基因小麦扬麦18,并能在转基因小麦中遗传、转录表达;5个转BvGLP1基因小麦株系的根腐病抗性比受体品种扬麦18有显著提高,说明BvGLP1过表达增强了转基因小麦对根腐病的抗性.

  19. Alternativas de control en la pudrición radical de cebolla para el Valle de la Trinidad, Baja California Control Alternatives for Onion root rot in the Trinity Valley, Baja California

    Directory of Open Access Journals (Sweden)

    Armando Pulido-Herrera

    2012-02-01

    Full Text Available La pudrición radical en cebolla es la enfermedad más importante en el Valle de la Trinidad, Baja California, México. Con el propósito de evaluar estrategias de control para la enfermedad se realizaron tres experimentos durante 2007, 2008 y 2009. En el experimento I (2007 los tratamientos fueron: 1 Tiofanato metílico; 2 Smicobac (Trichoderma + Bacillus sp. + Azospirillum sp. + Pseudomonas sp.; 3 estiércol de bovino (EB; 4 residuos de cebolla (RC; 5 solarización plástico transparente (SPT, 6 solarización plástico negro (SPN; 7 SPT + EB; 8 SPT + RC; 9 SPN + EB; 10 SPN + RC; 11 Trichodef (Trichoderma harzianum;y 12testigo. En el experimento II (2008, los tratamientos fueron los mismos excepto el tratamiento 2, sustituido porprotector (extractos vegetales; y en el experimento III (2009 los tratamientos fueron: 1 SPT + estiércol de ovino (EO; 2 SPN + EO; 3 SPT; 4 SPN; 5 control biológico (Trichoderma spp.; y 6 control químico (2- (tiocianometiltio benzotiazol 30%. Los resultados indicaron que los tratamientos solarización plástico transparente con o sin enmiendas orgánicas, presentaron incrementos significativos (p≤ 0.05 de 22 a 34% en el rendimiento y diámetro del bulbo con respecto al control biológico y químico; sin embargo, en estos dos últimos tratamientos la incidencia y severidad se redujo significativamente (p≤ 0.05, por lo que la solarización con plástico transparente y el control biológico, son alternativas viables para el control de la pudrición radical en cultivos de cebolla en Baja California, México.Onion's root rot is the most important disease in the Trinidad Valle, Baja California, Mexico. In orderto evaluate strategies to control this disease, three experiments were conducted during 2007, 2008 and 2009. In experiment I (2007 the treatments were: 1 Thiophanate methyl; 2 Smicobac (Trichoderma+Bacillus sp. + Azospirillum sp. + Pseudomonas sp.; 3 cattle manure (EB; 4 waste of onion (RC; 5 clear plastic

  20. ldentification and Control Methods of Eggplant Southern Blight, Damp-ing-off, Root Rot, Verticil-lium Wilt and Fusarium Wilt%茄子白绢病、猝倒病、根腐病、黄萎病和枯萎病的识别与防治

    Institute of Scientific and Technical Information of China (English)

    高焕; 郑丹丹

    2012-01-01

    介绍了茄子白绢病、猝倒病、根腐病、黄萎病和枯萎病的危害症状、发病特点,并从农业措施、化学防治等方面总结了各病害的综合防治方法。%The symptom and disease characteristics of eggplant southern blight, damping-off, root rot, verticillium wilt and fusarium wilt were introduced. Then the integrated control methods were put forward, which contained measures of agricultural control, chemical control and so on.

  1. Biological control of Phytophthora root rot of avocato with microorganisms grown in organic mulches Controle biológico da podridão radicular de Phytophthora no abacateiro utilizando substratos orgânicos colonizados

    Directory of Open Access Journals (Sweden)

    Jefferson L. da S. Costa

    2000-10-01

    Full Text Available Organic mulches colonized with microbial biocontrol agents, termed bioenhanced mulches, were tested for their ability to reduce Phytophthora root rot of avocado (Persea americana Mill.. Benomyl-resistant mutants of Gliocladium virens (KA 230-1 and Trichoderma harzianum (KA 159.2 isolated from suppressive soils and selected as efficient antagonists of P. cinnamomi were evaluated for their ability to colonize different mulches under controlled laboratory conditions. Sudangrass and a coarse yardwaste were found to be better substrates than a fine yardwaste, woodwaste or rice hulls for biocontrol agents propagules production. The most suitable conditions for colonization were an optimum temperature of 24°C, a moisture content of 20% for sudangrass and 30% for the coarse yardwaste, and a continuous light exposure during a 15-day incubation period. In the greenhouse, fresh sudangrass and a coarse yardwaste colonized with G. virens and used as a surface mulch proved to be the best combination for reducing the population of P. cinnamomi in 4-liter pots containing artificially-infested soil. Healthy avocado roots made up 31-37% of the roots in the G. virens-mulch combinations compared to 0% healthy in infested controls after two months.Compostos orgânicos colonizados com agentes de controle microbiológico, então denominados compostos bioativados, foram testados quanto a sua habilidadade controlar à podridão radicular de Phytophtora no abacateiro (Persea americana Mill. Mutantes de Gliocladium virens (KA 230-1 e Trichoderma harzianun (KA 159-2 resistentes a benomyl recuperados de solos supressivos e selecionados como eficientes antagonistas à P. cinnamoni foram avaliados quanto à sua capacidade de colonizar diversos compostos orgânicos em condições de laboratório. O Capim Sudão e um Composto de Jardim de alta granulação demonstraram quanto à sua capacidade de multiplicar propágulos de agentes de biocontrole, serem superiores à um

  2. 8种植物挥发物和浸提液对三七根腐病菌的抑制活性研究%The Study of Inhibitory Activity of Eight Plant Volatiles and Extracts to Panax notoginseng Root Rot Pathogens

    Institute of Scientific and Technical Information of China (English)

    张伟; 廖静静; 朱贵李; 张卉; 段晓龙; 朱书生; 杨敏

    2013-01-01

    The purpose of this study was to screen crops which volatiles and extracts showing antifungal activity, and use them for rotation to control Panaxnotoginsengroot rot. This study tested the inhibitory activity of 8 plant volatiles and extracts to Phytophthora cactorum and Fusarium solani, the casual agent of panax notoginseng root rot using mycelial growth rate method. The results revealed that the volatiles and extracts of Alliumsativum, A.epa, A.tuberosum, A.fistulosumshowed obvious inhibition activity against P.cactorum and F. solani and the inhibition activity of A. sativum was the strongest. The volatiles of Zingiber officinale, Houttuynia cordata, Coriandrum sativum and Mentha haplocalyx had little inhibition activity on P. cactorum and F.solani, sometimes accelerated colony growth when treated with low concentration. However, the extracts of Z.officinale, the root and leaf of C.sativumshowed distinct inhibitory activity to P.cactorumand F.solani. This data would provide scientific basis for using rotation of these crops to control Panax notoginseng root rot, achieving ecological control of Panaxnotoginsengroot rot.%筛选挥发物及浸提液具有抑菌活性的作物,用于与三七轮作防治根腐病。采用菌丝生长速率法测定了8种植物的挥发物和浸提液对引起三七根腐病的恶疫霉菌和腐皮镰孢菌的抑制活性。葱属作物大蒜、洋葱、葱及韭菜的挥发物和浸提液对恶疫霉菌和腐皮镰孢菌均具有明显的抑制效果,且大蒜挥发物和浸提液的抑菌活性最强;生姜、鱼腥草、香菜茎和薄荷的挥发物抑菌效果不明显,甚至在低浓度下出现促进菌丝生长的现象,而生姜、香菜根和叶的浸提液则表现出明显的抑菌活性。本研究结果可为利用作物轮作控制三七根腐病提供科学依据,有利于实现三七根腐病的生态防控。

  3. Identification of Fusarium Pathogens for Root Rot of Vicia faba L.at Seedling Stage in the Cold and Humid Regions of Gansu%甘肃高寒阴湿地区蚕豆苗期镰刀菌根腐病病原鉴定

    Institute of Scientific and Technical Information of China (English)

    侯思雯; 李敏权; 杨晓明; 杨发荣

    2011-01-01

    Isolation and culture of typical diseased plants of Viciafaba L. With fusarium root rot at seedling stage in the cold and humid regions of Linxia, 34 single-spore isolates of fusarium were obtained and identified, which belonged to Fusarium solani, Fusarium semitectum and Fusarium dimerum, respectively. Their pathogenicity was tested by using pot inoculation and.culture plate inoculation in laboratory. The results showed that all isolates had strong pathogenicity to seedlings of Viciafaba L., in which the Fusarium semitectum and Fusarium dimerum were the pathogens for root rot of Viciafaba L. At seedling stage is the first confirmed record.%对临夏高寒阴湿地区蚕豆苗期镰刀菌根腐病典型病株进行分离培养,共获得34个镰刀菌单孢菌株,经鉴定分别是茄镰刀菌(Fusarium solani)、半裸镰刀菌(Fusarium semitectum)和单隔镰刀菌(Fusarium dimerum).采用室内盆栽接种和平皿接种法测定致病性,结果表明,茄镰刀菌、半裸镰刀菌和单隔镰刀菌对蚕豆幼苗都有较强的致病性.其中,半裸镰刀菌和单隔镰刀菌是蚕豆苗期根腐病病原属首次报道.

  4. Diaporthaceae associated with root rot of maize

    NARCIS (Netherlands)

    Lamprecht, S.C.; Crous, P.W.; Groenewald, J.Z.; Tewoldemedhin, Y.T.; Marasas, W.F.O.

    2011-01-01

    We investigated the identity and genetic diversity of more than 100 isolates belonging to Phyllosticta (teleomorph Guignardia), with particular emphasis on Phyllosticta citricarpa and Guignardia mangiferae s.l. occurring on Citrus. Phyllosticta citricarpa is the causal agent of Citrus Black Spot and

  5. Reaction of arracacha genotypes to the root soft rot caused by Pectobacterium chrysanthemi Reação de genótipos de mandioquinha-salsa à podridão-mole das raízes causada por Pectobacterium chrysanthemi

    Directory of Open Access Journals (Sweden)

    Gilmar Paulo Henz

    2005-01-01

    Full Text Available The purpose of this paper was to screen thirty-two arracacha genotypes for their reaction to root soft rot. Twenty roots of each genotype were inoculated with two Pectobacterium chrysanthemi isolates in a randomized experiment (10 roots/isolate. After inoculation, roots were individually wrapped with PVC film and kept at 26ºC in closed plastic bags. Soft rot lesions were recorded after 36 hours and genotypes were grouped in four classes of susceptibility by cluster analysis: 10 were less susceptible, 16 intermediate, 3 susceptible and 3 very susceptible. All the tested arracacha genotypes showed only variation in the degree of susceptibility.O objetivo deste trabalho foi avaliar a reação de 32 genótipos de mandioquinha-salsa à podridão-mole das raízes. Vinte raízes de cada genótipo foram inoculadas com dois isolados de Pectobacterium chrysanthemi em um experimento casualizado (10 raízes/isolado. Após a inoculação, as raízes foram embaladas com filmes de PVC e mantidas a 26ºC em sacos de plástico. As lesões de podridão-mole foram avaliadas após 36 horas e os genótipos agrupados em quatro classes de suscetibilidade por análise de agrupamento: 10 foram menos suscetíveis, 16 intermediários, 3 suscetíveis e 3 muito suscetíveis. Todos os genótipos avaliados demonstraram apenas variação no grau de suscetibilidade.

  6. Impact of management strategies in the basal rot, charcoal rots epidemiology and Phaseolus vulgaris L. yield.

    Directory of Open Access Journals (Sweden)

    Ulacio Osorio Dilcia

    2013-02-01

    Full Text Available The effect of chemical, physical, biologycal and cultural strategies individually or combinated were evaluated in the epidemiology of the basal rot (Sclerotium rolfsii, charcoal rot (Macrophomina phaseolina and the Phaseolus vulgaris cv Tacarigua yield at Barinas state from Venezuela. In the experiment, Tebuconazole (Teb was applicated at seed (1 L/Ton and at soil, a los 30 y 60 days after of the sow (1 L/ha; Trichoderma harzianum (Tri was applicated at seed (15 g for each 1.5 k and to 15, 30, 45 y 60 days after of the sow (30 g/10 L of water. On the other hand, soil was solarizated (Sol during 15 days and calcium nitrate (Ca (60 g/10 L of water was applicated each 15 days until 60 days of growth of cultivated plants. Basal rot was registered as far as 42 days after of the sow, showing less of 5.3% in Teb y the combination SolTeb. The hightest incidence of this disease was observed in the treatment Tri with 28.5%, being highter that control (14.5%. Last to 42 days predominated the charcoal rot in the rest of the plants for a total of 100% of incidente in everything the treatments. Nevertheless, Teb showed the hightest yield with 555 k/ha, being different estatistically at treatment TriCa, which showed the lowest yield with 31 k/ha, however, the roots not formed nodules nitrogen uptake in these replications with the fungicide and Ca. It is concluded that S. rolfsii was sensible at action of some of the treatments; but not M. phaseolina; nevertheless, the plants were capables to produce seeds health apparently in treatments in which observed less severity of charcoal rot.

  7. 枯草芽孢杆菌YB5对菜豆根腐病菌的抑菌机制测定及应用%Application and Antagonistic Mechanism of Bacillus subtilis YB5 Gainst Fusarium solani Causing Green Bean Root Rot

    Institute of Scientific and Technical Information of China (English)

    赵长龙; 赵慧妍

    2016-01-01

    Fusarium root rot of bean caused by Fusarium solani f .sp . phaseoli is an important disease of this crop worldwide and has economic impact in green bean producing areas .In order to biological control ,Bacillus subtilis YB5 was a potential bacterial biocontrol agent against F .solani causing green bean root rot .And appli‐cation and antagonistic mechanism of YB5 against F .solani was tested .The results showed that secondary me‐tabolite production by YB5 could effectively inhibit mycelial growth ,spores bearing and germination of F .sola‐ni and was sensitive to high‐temperature .And YB5 bacterial suspension had no effect on green bean seeds ger‐mination and could encourage root development .YB5 secondary metabolite and bacterial suspension could ef‐fectively protect green bean against root rot caused by F .solani .And its control effect was up to 94 .6% by potted plant experiments .%腐皮镰孢引起的菜豆根腐病是一种世界性病害,在菜豆生产中危害严重。为对其有效的生物防治,针对菜豆根腐病利用枯草芽孢杆菌进行了拮抗机制及应用的研究。结果表明:YB5能有效抑制菌丝生长、孢子产生和萌发。YB5的无菌滤液对高温敏感。YB5菌液对种子发芽没有抑制作用,且能促进根系的发育。YB5菌液及无菌滤液对菜豆腐皮镰孢根腐病的盆栽均具有较好的防效,YB5菌液防效可达94.6%。

  8. Antagonism of Trichoderma spp.to Fungi Caused Root Rot of Sophora tonkinensis%木霉菌对山豆根根腐病菌的拮抗作用

    Institute of Scientific and Technical Information of China (English)

    覃柳燕; 蒋妮; 唐美琼; 缪剑华; 李林轩

    2011-01-01

    目的:研究木霉菌对山豆根根腐病菌茄腐镰孢S9(Fusarium solani)的拮抗作用,探讨生物防治菌在防治中药材土传病害上的应用前景.方法:采用生长速度法、对峙培养法研究哈茨木霉H2(Trichoderma harsianum)、绿色木霉M6(Trichoderma viride)和康宁木霉K1(Trichoderma koningii)对山豆根根腐病菌S9的拮抗作用,并讨论了其作用机理.结果:发现H2、M6竞争优势显著,生长速度分别是S9的1.43~2.72倍和1.43~1.95倍;K1的空间竞争优势较弱,生长速度不如S9.3种木霉菌对S9均有不同程度的拮抗作用,其中,M6和H2对S9的拮抗作用较强,即使在提前3 d接入病原菌的情况下,M6和H2对S9的抑制率仍能分别达100%和82.35%,拮抗系数均达Ⅰ级;K1对S9的抑制率为46.36%,拮抗系数为Ⅳ级.在显微镜下观察到木霉菌通过缠绕、寄生等方式使S9发生菌丝断裂、缢缩、消解等现象.结论:哈茨木霉和绿色木霉作为生防菌在防治中药材土传病害上具有深入开发的前景.%Objective:To study the antagonism of Trichoderma spp. to fungi S9 ( Fusarium solani)which caused root rot of Sophora tonkinensis and discuss the further develop prospects of microbial biological control in soil-borne diseases on Chinese herbal medicines. Methods:Antagonism of H2 (Trichoderma harsianum ) , M6 (Trichoderma viride ) and K1 (Trichoderma koningii ) to Fusarium solani were researched by growth rate and confront culture. And their mechanisms were discussed. Results: H2 and M6 had obvious competitive advantage, the growth rate of which were 1.43 ~ 2. 72 times and 1.43 ~ 1.95 times as S9 respectively. The space competitive advantage of K1 was relatively weak ;the growth rate was slower than S9. The antagonism of three species of Trichoderma spp. to S9 was in varying degrees. The antagonism to S9 of M6 and H2 was better,the inhibition rate were 100% and 82. 35% respectively,even cultivated S9 for three days in advance. And their

  9. Toxicity Assay of Several Chemical Fungicides Against Pathogen of Wheat Root Rot%6种杀菌剂对小麦叶斑根腐病菌的毒力测定

    Institute of Scientific and Technical Information of China (English)

    袁胜亮; 刘峰; 张娜

    2011-01-01

    Screening and management of high performance chemical fungicide was the important way to control wheat disease caused by Bipolaris sorokiniana. Suitable fungicide used in the field could be sreened by virulence testing in laboratory. The inhibition of 6 kinds of fungicides on B. sorokiniana, the phynotype of wheat root rot, was studied using biometric methods in this study. The results showed that different fungicides on colony growth was different, in which Difenoconazole was the most effective one to the pathogen, 94.9%inhibition rate was obtained when the concentration was 40 mg/L. Metiram, Propineb, Thiram, Carbendazim and Mancozeb were effective in mm, with the inhibition rate of 89.5%, 86.3%, 48.2%, 40% and 37.8%,respectively. Strong inhibition of spore germination was also displayed with Difenoconazole, hemi-inhibitory concentration was 6.45 mg/L, showed that this agent can be used in production continuously.%筛选高效的防治药剂并研究出其配套的田间防治应用技术是防治小麦根腐病的重要措施,而通过不同杀菌剂对病原菌的毒力测定分析,可为田间防治药剂的筛选提供重要的参考依据.此研究采用生物测定的方法,研究了6种化学药剂对小麦叶斑根腐病菌菌丝生长的抑制作用.结果表明,不同药剂对病原菌生长的影响不同,世高对菌丝生长的抑制作用最显著,在质量浓度为40 mg/L时抑制率达94.9%;其次为唑醚-代森联、丙森锌、福美双、多菌灵和代森锰锌,在该浓度下对菌丝生长抑制率依次为89.5%、86.3%、48.2%、40%和37.8%.对病原菌菌丝生长抑制效果最好的世高对病原菌孢子萌发同样具有强烈的抑制作用,抑制萌发中浓度为6.45 mg/L,可在生产中继续合理使用.

  10. Field Efficiency Trial of 72% Streptomycin against Konjac Bacterial Soft Rot

    Institute of Scientific and Technical Information of China (English)

    Huang; Yongsheng; Li; Xiaojun; Zhu; Shijin; Ma; Yongsheng; Wang; Li

    2014-01-01

    72% Streptomycin soluble powder was used to control konjac bacterial soft rot in the study. The control efficiency and yield of different treatments were investigated,and the benefit was analyzed. The control scheme against konjac bacterial soft rot was as follows: spraying 72% atreptomycinon twice on rotation fields after all the seedlings were strong and uniform,or irrigating roots with 72% atreptomycinon once and spraying twice on continuous cropping fields.

  11. 朝鲜蓟细菌性根茎腐烂病病原的分离与鉴定%Isolation and identification of bacterial pathogen causing stem and root rot on artichoke

    Institute of Scientific and Technical Information of China (English)

    王晓丽; 夏花; 张平喜; 朱宏建; 高必达

    2012-01-01

    A new disease on globe artichoke (Cynara scolymus L.) was observed in commercial fields in Changde, Hunan Province, China. Typical symptoms were wilting and necrosis from the outermost leaves, dark brown discoloration of the vascular tissue and pith of main stem. Eventually, the plants wilted and died. Manual weeding and cuttings often led to the development of typical soft rot during propagation. To investigate the causal agent of the disease, isolations were made from rotted stems of field artichoke plants on nutrient agar (NA). Bacteria consistently isolated from the diseased tissues formed grey-white, glossy, convex, translucent, and round colonies on NA. The bacterial cells were gram-negative rods with 2 to 8 peritrichous flagclla and rounded ends under the microscope. In artificial inoculation test, these isolates could also cause stem rot of Chinese cabbage, pepper, lettuce and artichoke, and slice rot of carrot, tomato and potato within 48 h at 28t!. The results demonstrated that these isolates are causative agent of soft-rot disease. PCR amplification was carried out by utilizing universal 16S rDNA primer pair 16SF/16SR and pel gene primers Y1/Y2. The 16S rDNA and pel gene sequences of isolate HNXDT002 (GenBank accessions JF721958 and JF721960, respectively) had 99% and 93% nucleotide identity with strains of Pectobacterium carotovorum subsp.carotovorum (GenBank accessions U80197 and CP001657, respectively). It came to the conclusion that the causal agent of soft-rot disease on artichoke belonged to Pectobacterium carotovorum subsp. carotovorum.%在湖南省常德市西洞庭管区种植的朝鲜蓟(Cynara scolumus L.)上发现了一种新的病害,其症状表现为地上部分从外层叶片开始逐步枯萎,随后根部和主茎杆的髓部腐烂变褐,最后整株枯萎.从田间感病朝鲜蓟茎杆的病健交界处用NA 培养基分离,获得10个菌株,分别指定为HNXDT001~010,并进行了致病性测定、形态观察和细

  12. Identification of the pathogen isolated from root rot of Taxus chinensis var.mairer and screening of its antagonistic Bacillus%南方红豆杉根腐病病原及其拮抗芽胞杆菌的鉴定

    Institute of Scientific and Technical Information of China (English)

    谯天敏; 罗蓉; 朱天辉

    2015-01-01

    In this study,the pathogen isolated from root rot of Taxus chinensis var.mairer was first indentified. Based on morphological characteristics,pathogenicity and rDNA ITS sequence analysis,the results showed that the pathogen of root-rot disease of T .chinensis var.mairer was Fusarium oxysporum .The tablet confrontation training method was adopted to screen the antagonistic Bacillus species from the healthy plant rhizosphere,and three strains with obvious antagonistic effect were obtained,namely YB6,YB1 5 and YB37.Through morphologi-cal,physiological,biochemical and 1 6S rDNA homology analysis as well as the construction of 1 6S rDNA phy-logenetic tree,we found that YB6,YB15 and YB37 were Bacillus cereus ,B .amyloliquefaciens and Paenibacillus poly-myxa ,respectively.The antagonistic effect of P .polymyxa was the best with further research and development potential. This study provides some valuable information for effective prevention and treatment of this disease.%经形态学特征观察、致病性测定及 rDNA-ITS 序列分析,首次确定红豆杉根腐病病原为尖孢镰刀菌(Fusari-um oxysporum )。采用平板对峙培养法从健康植株根际土壤中筛选得到3株对尖孢镰刀菌具有明显拮抗作用的芽胞杆菌 YB6、YB15、YB37。经形态学、生理生化及16S rDNA 同源性分析,并通过构建16S rDNA 系统发育树,将YB6、YB15和 YB37分别鉴定为蜡样芽胞杆菌(Bacillus cereus )、解淀粉芽胞杆菌(B .amyloliquefaciens )和多黏类芽胞杆菌(Paenibacillu polymyxa ),其中多黏类芽胞杆菌拮抗效果最好,具有进一步研究开发的潜力。本研究通过对南方红豆杉根腐病病原鉴定及其拮抗芽胞杆菌的筛选,对该病的防治提供了理论依据。

  13. Preparation of Algae Agents forS. miltiorrhiza Bunge Root Rot BiocontrolBacillus subtilis2-1%丹参根腐病生防芽孢杆菌2-1海藻菌剂的研制

    Institute of Scientific and Technical Information of China (English)

    周莹; 袁孟娟; 韩军; 陈芳

    2015-01-01

    With algae residue as carrier,S. miltiorrhiza bunge root rot biocontrol agents:Bacillus subtilis2-1(CGMCC No.9256), were developed into algae agents, which features both nutritional and cell biological control function, also in line with the basic indicators of agricultural products, technical indicators microbial agents. Then appropriate ratio of seaweed broth and residue was chosen by physical means. Besides, the number of viable cells, moisture content, pH value and expiration date were measured by agricultural product quality testing methods, and field experiments was conducted to test biocontrol effect. Results showed that number of effective viable agents was 2.32×109/g, moisture content was 6.75%, pH value was 6.7, and the expiration date was about 11.6 months , all of which were in line with the technical specifications of the particles. The incidence of root rot in field trials rate decreased 37.6% compared with the blank control group, the effect of biocontrol was obvious.%以海藻渣为载体,菌种为丹参根腐病生防菌:枯草芽孢杆菌Bacillus subtilis2-1(已保存CGMCC No.9256),研制成的海藻菌剂兼具营养及生物防治功能,同时菌剂的基本指标符合农用微生物菌剂产品的技术指标。用物理方法选择菌种发酵液与海藻渣混合的最佳配比,结合农用微生物菌剂产品质量检测方法对菌剂中有效活菌数、含水量、pH值及有效期进行测定,并进行大田试验,测试生防效果。菌剂有效活菌数为2.32×109/g,含水量为6.75%,pH值为6.7,常温下有效期约为11.6个月,均符合颗粒菌剂的技术指标,大田试验中根腐病的发病率比空白对照组降低37.6%,生防效果较为显著。

  14. Isolation and Identification of Antagonistic Bacterium Strain JK-7Against the Pathogenic Fungi Causing Mulberry Root Rot Disease%桑树根腐病真菌病原拮抗细菌JK-7的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    张艳东; 曹梦琪; 王俊; 王凯旋; 孙国霞; 吴福安

    2013-01-01

    Mulberry root rot is a soil-borne infectious disease in mulberry root. In order to implement biological control a-gainst mulberry root rot disease, 84 strains of Bacillus were isolated from mulberry rhizospheric soil. A Bacillus strain which has antagonistic activity against Fusarium solani strain FS-1, the pathogenic fungi causing mulberry root rot disease, was screened by confrontation culture method and numbered as JK-7. The colonial morphology of strain JK-7 on LB medium was translucent, smooth and waxy on surface, and irregular at edge. Strain JK-7 is a Gram positive bacterium, rod-shaped and 0. 5 ~0. 7 μm ×1. 0 ~1. 2 μm in size. The oval-shaped spores located on middle or sub-terminal of bacterium. This strain could make use of starch and tyrosine. Its parasporal crystal was determined to be negative and reaction with peroxidase was positive. 16S rDNA sequence of strain JK-7 was amplified by PCR using a pair of bacterial universal primers and the obtained fragment size was 1 477 bp. Phylogenetic tree revealed that strain JK-7 had the closest genetic relationship with Bacillus cereus. Taken together, strain JK-7 was identified as Bacillus cereus. Plate confrontation test showed that strain JK-7 had inhibitory effect on hypha growth of pathogenic strain FS-1. Scanning electron microscopic observation indicated that strain JK-7 colonized on the surface of hyphae of FS-1, and caused deformity and breakage of mycelia, showing antagonistic effect to FS-1.%桑树根腐病是一类土壤传染性桑树根部病害.为了实施对这类病害的生物防治,从桑树根际土壤分离到84株芽孢杆菌,通过对峙培养法从中筛选出一株对桑树根腐病真菌病原腐皮镰刀菌(Fusarium solani)FS-1具有拮抗作用的菌株,将该菌株编号为JK-7.JK-7菌株在LB培养基上的菌落呈半透明、光滑蜡状,边缘不规则;为革兰阳性菌,杆状,大小0.5~0.7μm×1.0~1.2 μm,芽孢呈椭圆形,位于菌体中部或亚末端;菌株能

  15. ldentification and Control Methods of Eggplant Bacterial Wilt, Soft Rot, Necrotic Leaf Spot, Mo-saic Virus, Root-knot Ne-matode Disease, Sun-scald, Leaf Scorch and Dehiscent Fruit%茄子青枯病、软腐病、细菌性褐斑病、病毒病、根结线虫病、日灼病、叶烧病和裂果的识别与防治

    Institute of Scientific and Technical Information of China (English)

    郑丹丹; 张杨林

    2012-01-01

    介绍了茄子青枯病、软腐病、细菌性褐斑病、病毒病、根结线虫病、日灼病、叶烧病和裂果的危害症状、发病特点,并从农业措施、化学防治等方面总结了各病害的综合防治方法。%The symptom and disease characteristics of eggplant bacterial wilt, soft rot, necrotic leaf spot, mosaic virus, root-knot nematode disease, sunscald, leaf scorch and dehiscent fruit were in-troduced. Then the integrated control methods were put forward, which con-tained measures of agricultural control, chemical control and so on.

  16. Endophytic Trichoderma gamsii YIM PH30019: a promising biocontrol agent with hyperosmolar, mycoparasitism, and antagonistic activities of induced volatile organic compounds on root-rot pathogenic fungi of Panax notoginseng.

    Science.gov (United States)

    Chen, Jin-Lian; Sun, Shi-Zhong; Miao, Cui-Ping; Wu, Kai; Chen, You-Wei; Xu, Li-Hua; Guan, Hui-Lin; Zhao, Li-Xing

    2016-10-01

    Biocontrol agents are regarded as promising and environmental friendly approaches as agrochemicals for phytodiseases that cause serious environmental and health problems. Trichoderma species have been widely used in suppression of soil-borne pathogens. In this study, an endophytic fungus, Trichoderma gamsii YIM PH30019, from healthy Panax notoginseng root was investigated for its biocontrol potential. In vitro detached healthy roots, and pot and field experiments were used to investigate the pathogenicity and biocontrol efficacy of T. gamsii YIM PH30019 to the host plant. The antagonistic mechanisms against test phytopathogens were analyzed using dual culture, scanning electron microscopy, and volatile organic compounds (VOCs). Tolerance to chemical fertilizers was also tested in a series of concentrations. The results indicated that T. gamsii YIM PH30019 was nonpathogenic to the host, presented appreciable biocontrol efficacy, and could tolerate chemical fertilizer concentrations of up to 20%. T. gamsii YIM PH30019 displayed antagonistic activities against the pathogenic fungi of P. notoginseng via production of VOCs. On the basis of gas chromatography-mass spectrometry, VOCs were identified as dimethyl disulfide, dibenzofuran, methanethiol, ketones, etc., which are effective ingredients for antagonistic activity. T. gamsii YIM PH30019 was able to improve the seedlings' emergence and protect P. notoginseng plants from soil-borne disease in the continuous cropping field tests. The results suggest that the endophytic fungus T. gamsii YIM PH30019 may have a good potential as a biological control agent against notoginseng phytodiseases and can provide a clue to further illuminate the interactions between Trichoderma and phytopathogens.

  17. 大豆种质对花叶病毒病和疫霉根腐病抗病性的SSR标记辅助鉴定%SSR Identification of Soybean Cultivar with Resistance to Soybean Mosaic Virus and Phytophthpra Root Rot

    Institute of Scientific and Technical Information of China (English)

    韩英鹏; 赵雪; 李修平; 滕卫丽; 李文滨

    2014-01-01

    通过与花叶病毒病(soybean mosaic virus,SMV)抗性相关的SSR标记Satt114对30份大豆种质进行分子辅助鉴定,共发现10个抗SMV的种质,经摩擦接种法表型验证其中9个种质表现为抗病,即分子辅助鉴定的准确性为90%.另外,利用与疫霉根腐病(phytophthora root rot,PRR)相关的SSR标记Satt325、Satt343、Satt428、Satt005、Satt600、Satt611、Satt689、Satt579、Satt252、Satt274对相同的30份大豆种质进行分子辅助鉴定,共在2,3,5,6,12,2份大豆种质上分别检测到0,1,2,3,4,5个抗PRR的QTL,并利用菌土法盆栽验证种质的抗病性,结果表明拥有0~1个抗PRR的QTL大豆种质的病害损失率平均为94%,拥有2~3个抗PRR的QTL大豆种质的病害损失率平均为77.82%,拥有4~5个抗PRR的QTL大豆种质的病害损失率平均为36.70%.通过本研究筛选获得了1份既高抗SMV又高抗PRR的种质合05-31.

  18. Screening,identification and antibacterial activity of antagonistic bacteria FC12-05 against phytophthora root rot of tomato%番茄疫霉根腐病拮抗细菌FC12-05的筛选、鉴定及其抑菌活性初探

    Institute of Scientific and Technical Information of China (English)

    冯志珍; 李金岭; 陈太春; 马志远; 段军娜; 安德荣

    2012-01-01

    【Objective】 The strong effective biocontrol bacteria for phytophthora root rot of tomato were selected from greenhouse tomato farming soil for several years.【Method】 Random samples were conducted from greenhouse tomato farming soil for many years,separated the bacteria used plant dilute,selected directionally with several fungal pathogens such as P.capsici Leonian,Botrytis cirerea,Phytophthora nicotianae,Bipolaris sorokiniana,Fusarium oxysporum f.sp.vasinfectum,Pyricularia oryzae as the indicator bacteria;We identified the antagonistic bacteria based on morphological,physiological and biochemical characteristics,and 16S rDNA phylogenetic analysis;determined the effect of the mycelial configurationthe of pathogenic fungi,the mycelium growth of pathogenic fungi,the spore germination on pathogenic fungi spores broth germination and the control efficacy of bonsai experiment in greenhouse with the sterile fermentation of antagonistic bacteria.Then we deposited the sterile fermentation of antagonistic bacteria with ammonium sulfatem,which saturation concentration respectively was 10%,20%,25%,30%,35%,40%,50%,60%,70%,80%,90% and 100%,and tested the antifungal activity of ammonium sulfate precipitation of the antagonists.【Result】 253 strains bacterium were isolated from 30 soil samples,FC12-05,a strong effect of bacterial on Phytophthora capsici Leonian,Botrytis cirerea,Phytophthora nicotianae,Bipolaris sorokiniana,Fusarium oxysporum f.sp.vasinfectum,Pyricularia oryzae;The strain FC12-05 was identified as Bacillus siamensis.The fermented liquid of strain FC12-05 had great inhibition effect on mycelium growth of P.capsici Leonian and Botrytis cinerea,the inhibition rate of mycelium growth was 95.02% and 92.43%;the EC50 values was 10.14 and 10.78 mL/L;the inhibition rate of spore germination was 94.60% and 92.43%;the EC50 values was 2.09 and 2.53 mL/L;the control effect of FC12-05 strain on phytophthora root rot of tomato was up to 93.50%;The antifungal metabolite

  19. 7 CFR 29.6039 - Stem rot.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Stem rot. 29.6039 Section 29.6039 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... INSPECTION Standards Definitions § 29.6039 Stem rot. The deterioration of an uncured or frozen stem...

  20. Antagonistic potential of fluorescent pseudomonads and control of charcoal rot of chickpea caused by Macrophomina phaseolina.

    Science.gov (United States)

    Kumar, Vinod; Kumar, Anuj; Kharwar, R N

    2007-01-01

    The effectiveness of plant growth promoting rhizobacteria especially Pseudomonas fluorescens isolates were tested against charcoal rot of chickpea both in green house as well as in field conditions. Most of the isolates reduced charcoal rot disease and promoted plant growth in green house. A marked increase in shoot and root length was observed in P. fluorescens treated plants. Among all the P. fluorescens isolates Pf4-99, was found most effective in the improvement of chickpea crop in green house as well as in field. Pf4-99 effectively promoted plant growth and produced indole acetic acid in culture medium. This isolate also inhibited the mycelial growth of the M. phaseolina under in vitro conditions and reduced the disease severity Potential isolate (Pf4-99) also significantly increased the biomass of the chickpea plants, shoot length, root length and protein content of the chickpea seeds. A part from these, the total number of seeds per plant and their weight were also enhanced. The colonization of Pf4-99 reduced the incidence of seed mycoflora by which indirectly enhanced the seed germination and vigour index of seedlings. The observations revealed that isolate Pf4-99 is quite effective to reduce the charcoal rot disease both in field and greenhouse, and also increases seed yields significantly Therefore, this isolate appears to be an efficient biocontrol agent against charcoal rot disease as well as yield increasing rhizobacterium.

  1. Water relations in untreated and modified wood under brown-rot and white-rot decay

    DEFF Research Database (Denmark)

    Thybring, Emil Engelund

    2017-01-01

    One key requisite for fungal decay of wood is water within cell walls. While several reviews have focused on the mechanistic relationship between water and decay of wood, this study is the first review of water relations of decayed wood material. Based on a vast compilation of experimental data...... from several literature sources, the water relations of untreated and modified wood decayed by brown-rot and white-rot fungi are examined. The aim is to investigate to what extent observations and assumptions regarding brown-rot and white-rot decay can explain changes in water relations observed during...... and after decay. Although the available experimental data for modified wood is scarce, it indicates that brown-rot and white-rot decay of non-resistant modified wood occurs by similar degradation mechanisms with similar effects on water relations as for untreated wood. From simplistic, mathematical...

  2. Assessment of Production of Extracellular Enzymes by Trichoderma spp. For Control of Soybean Root Rot Pathogens (Fusarium oxysporum,Rhizoctonia solani)%木霉菌(胞外水解酶)拮抗大豆根腐病病原菌的机制研究

    Institute of Scientific and Technical Information of China (English)

    邵红涛; 许艳丽

    2006-01-01

    The role of extracellular enzymes by Trichoderma MM35 for control of soybean root rot pathogens(Fusarium oxysporum , Rhizoctonia solani) was assessed in vitro and in vivo. Detective levels of hydrolytic extracellular enzymes were recorded by Trichoderma MM35 using dried F. oxysporum mycelium as C-source in vitro or fresh F. oxysporum mycelium or fresh R.solani mycelium in vivo was found that there were significant increases in chitinase activities by Trichoderma MM35 in soil with inoculation of F. oxysporum. Soil infested with Trichoderma MM35 had significantly elevated chitinase and β-1,3-glueanase activities in presence of R. solani as compared to R. solani control.%通过室内试验与温室试验研究了具有生防能力的木霉菌株Trichoderma MM35所分泌的胞外水解酶在拮抗大豆根腐病病原菌(F.oxysporum、R.solani)中的作用.试验结果表明:以病原菌F.oxysporum烘干的菌丝体作唯一碳源,可以诱导Trichoderma MM35分泌几丁质酶、β-1,3-葡聚糖酶.β-1,3-葡聚糖酶高水平诱导表达在前,几丁质酶诱导表达在后.土壤中接种Trichoderma MM35、F.oxysporum和R.solani之后都能够检测到几丁质酶、β1,3-葡聚糖酶活性.向有病原菌F.oxysporum的土壤中接种Trichoderma MM35,土壤中几丁质酶活性能够显著升高.向有病原菌R.solani的土壤中接种Trichoderma MM35,土壤中的几丁质酶、β-1,3-葡聚糖酶活性都显著升高.

  3. Identification of bio-control bacterial strain KJB04-11 against soybean root rot disease and the produced lipopeptide antibiotics by the strain%大豆根腐病生防菌KJB04-11的鉴定及其产生的脂肽类抗生素

    Institute of Scientific and Technical Information of China (English)

    李旭; 马福海; 王秀娟; 孙健; 张惠文

    2012-01-01

    从大豆根围筛选到1株对尖孢镰刀菌和立枯丝核菌都具有很好拮抗作用的菌株KJB04-11,经形态观察、生理生化特征和16S rDNA序列分析,属于枯草芽孢杆菌(Bacillussubtilis).具有抗菌活性的KJB04-11发酵液无菌滤液对热和酸碱具有较强的稳定性.采用Sephadex G-25柱层析、反相HPLC和冷冻干燥从KJB04-11发酵液中分离纯化了抗菌活性成分.由红外光谱、MALDI-TOF-MS、氨基酸组成及脂肽合成酶基因扩增结果推测该菌株产生的抗菌物质为C16、C17的mycosubtilin和C15的surfactin.田间试验表明,大豆种子经KJB04-11发酵液包衣处理对大豆根腐病防效为53.6%,大豆产量提高12.5%.%A bacterial strain KJB04-11 with antagonistic effect against Fusarium oxysporum and Rhizoctonia solani was isolated from soybean rhizosphere. The strain was identified as Bacillus subtilis, based on its morphological, cultural, physiological, and biochemical characteristics, and 16S rDNA sequence analysis. The fermented filtrate with antagonistic activity showed certain thermostability and certain acidic and alkaline stability in the range of pH 1.0-13.0. The antagonistic active compositions in the fermented filtrate were purified by gel filtration on Sephadex G-25 column and RF-HPLC, and preliminarily identified as Cl6 mycosubtilin, C17 mycosubtilin, and C15 surfactin by infrared spectra, MALDI-TOF mass spectrum, amino acid composition analysis, and amplification of lipopeptide synthase gene. In field trial, the control efficacy of seed coating agent prepared with KJB04-11 against soybean root rot disease was 53. 6% , and the soybean yield was increased by 12.5% .

  4. Response of cultivars of malanga (Xanthosoma sagittifolium (L.) Schott) to dry rot

    OpenAIRE

    Ernesto Espinosa Cuéllar; Lidcay Herrera Isla; Alberto Espinosa Cuéllar; Amaurys Dávila Martínez; Alexander Bernal Cabrera; Jaime Simó González

    2017-01-01

    Malanga (Xanthosoma sagittifolium (L.) Schott) is an important food crop for over 400 million people in the tropics and subtropics. In order to determine the response of different varieties of malanga Xanthosoma to dry rot, a series of experiments were conducted in the period between 2012 and 2014. The experiments were performed on loamy Soil at the National Research Institute in Tropical Crops and Roots (INIVIT). We determined the incidence and severity of damage, yields and percent of losse...

  5. Strategies for managing foliar and root rot diseases of alfalfa

    Science.gov (United States)

    Diseases can be a major source of yield loss and stand decline in alfalfa. Surveys were conducted to determine the distribution of pathogens for which there is limited resistance in commercial varieties and tests were done with new crop chemicals to determine their effectiveness in controlling sever...

  6. improvement of resistance to fusarium root rot through gene ...

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    were crossed to each of the two susceptible cultivars to form five-parent and single crosses, respectively. Developed ... most effective control measure for FRR in common bean is through the ..... levels and/or stability of resistance beyond what.

  7. RHIZOBACTERIA AS BIOCONTROL AGENTS OF ROOT ROT DISEASE ON SHALLOT

    Directory of Open Access Journals (Sweden)

    Nunik Iriyanti Ramadhan

    2015-01-01

    Full Text Available Shallot is a high-economic value commodity, but so far the supply is still lower than the demand. One of the production problem is “moler” disease of shallot (MDS caused by Fusarium oxysporum f.sp. cepae (FOCe. The aim of this research was to study the potentiality of shallot rhizobacteria (SRB from various soil ordo to inhibit (MDS. This research was held in the Laboratory of Biology and Soil Health and Greenhouse at UNS. This research was carried out by exploring rhizobacteria of shallot planted on Entisols, Andisols, and Vertisols. Rhizobacteria exploration results were tested for their ability to control Fusarium oxysporum f.sp.cepae (FOCe. Inhibitory ability test of SRB to FOCe was carried out in vitro and on shallot in the greenhouse. The green house research used a Completely Randomized Design (CDR with two factors. The first factor was rhizobacteria combination and the second factor was various soil ordo (Andisols, Entisols, and Vertisols. Each treatment was replicated three times. It was obtained three rhizobacteria isolates from Vertisols (B15: 70%, Andisols (B12:45,55%, and Entisols (B10:46,67% being the highest inhibition results to FOCe. The combination of rhizobacteria B12 and B10 provided the lowest intensity.

  8. RESPONSE OF CABBAGE CULTIVARS TO BLACK ROT INFECTION

    African Journals Online (AJOL)

    Yield stability of white cabbage (Brassica oleracea var. capitata) cultivars were ... and stable cultivar(s) with adequate resistance to black rot caused by ..... Principles and Procedures of Statistics: ... black rot development in introduced cabbage.

  9. New source of bacterial soft rot resistance in potato tubers

    Science.gov (United States)

    Bacterial soft rot caused by Pectobacterium and Dickeya species can cause major losses to the potato (Solanum tuberosum L.) industry, mostly due to tuber rot in storage. There are few germplasm resources for soft rot resistance breeding. Here, we introduce a resistant diploid wild potato relative, M...

  10. QTL mapping of fruit rot resistance to the plant pathogen Phytophthora capsici in a recombinant inbred line Capsicum annuum population.

    Science.gov (United States)

    Naegele, R P; Ashrafi, H; Hill, T A; Chin-Wo, S Reyes; Van Deynze, A E; Hausbeck, M K

    2014-05-01

    Phytophthora capsici is an important pepper (Capsicum annuum) pathogen causing fruit and root rot, and foliar blight in field and greenhouse production. Previously, an F6 recombinant inbred line population was evaluated for fruit rot susceptibility. Continuous variation among lines and partial and isolate-specific resistance were found. In this study, Phytophthora fruit rot resistance was mapped in the same F6 population between Criollo del Morelos 334 (CM334), a landrace from Mexico, and 'Early Jalapeno' using a high-density genetic map. Isolate-specific resistance was mapped independently in 63 of the lines evaluated and the two parents. Heritability of the resistance for each isolate at 3 and 5 days postinoculation (dpi) was high (h(2) = 0.63 to 0.68 and 0.74 to 0.83, respectively). Significant additive and epistatic quantitative trait loci (QTL) were identified for resistance to isolates OP97 and 13709 (3 and 5 dpi) and 12889 (3 dpi only). Mapping of fruit traits showed potential linkage with few disease resistance QTL. The partial fruit rot resistance from CM334 suggests that this may not be an ideal source for fruit rot resistance in pepper.

  11. INFLUÊNCIA DA DENSIDADE DE INÓCULO DE Fusarium solani f.sp. phaseoli NA SEVERIDADE DA PODRIDÃO RADICULAR SECA DO FEIJOEIRO EFFECT OF Fusarium solani f.sp. phaseoli INOCULUM DENSITY ON DRY ROOT ROT SEVERITY IN THE COMMON BEAN

    Directory of Open Access Journals (Sweden)

    Gesimária Ribeiro Costa

    2007-09-01

    Full Text Available

    Foram testadas quatro densidades de inóculo de Fusarium solani, em gramas por litro de solo (1,0; 2,0; 4,0 e 8,0 e um tratamento testemunha, em solo tipo Latossolo Vermelho-Escuro, cultivado e não cultivado, com o objetivo de determinar a densidade mínima de inóculo no solo necessária para a ocorrência de podridão radicular seca do feijoeiro. Como variáveis respostas foram avaliadas: número de microorganismos totais do solo, número de propágulos de F. solani, atividade microbiológica total do solo e severidade da doença em plântulas. Os resultados indicaram que a densidade de inóculo do fungo variou com o tipo de solo. Para um solo não cultivado a densidade necessária para causar a doença esteve acima de 5.127 propágulos por grama de solo, enquanto para o solo cultivado a densidade de inóculo para causar doença foi de 3.701 propágulos por grama de solo. Os índices de doença em plântulas cultivadas sob o solo cultivado foram duas vezes superiores ao índice de doença de plântulas sob o solo não cultivado. A atividade microbiológica total nos solos, determinada pela desidrogenase de fluorescina diacetato, não se correlacionou com a população dos microorganismos, indicando que a simples presença desses não implica em que estejam ativos.

    PALAVRAS-CHAVE: Solo supressivo; solo conducivo; Phaseolus vulgaris.

    Four densities of Fusarium solani inoculum (1, 2, 4 and 8 g/L of soil were tested for determining the minimum inoculum density for the occurrence of bean dry root rot, in two soil types. The response variables evaluated were the total number of microorganisms in the soil, the number of F. solani f. sp. phaseoli propagules, total soil microbial activity and seedling disease severity

  12. Isolamento e seleção de fungos causadores da podridão-branca da madeira em florestas de Eucalyptus spp. com potencial de degradação de cepas e raízes Isolation and screening of wood white rot fungi from Eucalyptus spp. forests with potential for use in degradation of stumps and roots

    Directory of Open Access Journals (Sweden)

    Sandra Kunieda de Alonso

    2007-02-01

    Full Text Available Este trabalho objetivou isolar fungos causadores da podridão-branca da madeira, a partir de basidiocarpos e de fragmentos de madeira de eucalipto coletados em várias regiões do país, bem como testar seu potencial de degradação de cepas e raízes mortas em plantios comerciais de eucalipto, após o corte raso. Para o isolamento dos fungos foi desenvolvido um meio de cultura de serragem de eucalipto-ágar. Dentre 292 isolados obtidos e submetidos ao teste de Bavendamm, 144 foram classificados como causadores de podridão-branca, capazes de produzir fenoloxidases. Dentre as nove relações C/N testadas, observou-se uma tendência de ocorrer maior degradação de cavacos naquelas iguais a 60 : 1, 200 : 1 e 300 : 1. Utilizando a relação C/N igual a 60 : 1, realizaram-se dois experimentos para avaliar a degradação de cavacos de Eucalyptus saligna por isolados fúngicos de podridão-branca. No primeiro experimento, avaliado aos 90 dias de incubação, foram selecionados sete isolados, que causaram perda de peso em cavacos superior ou igual à causada por Trametes versicolor, usado para comparação. No segundo experimento foram testados 46 isolados fúngicos. Dentre os mais eficientes estavam os sete isolados selecionados no primeiro teste, além de outros quatro isolados. Baseado na análise de DNA, seis isolados foram identificados, sendo três pertencentes à espécie Pycnoporus sanguineus, um ao gênero Peniophora sp., um ao gênero Pestalotiopsis sp. e um ao gênero Ganoderma sp.The aim of this work was to isolate native wood white-rot fungi from fungal fruit-bodies and eucalyptus wood fragments from different regions of Brazil and to test their potential for degrading dead stumps and roots in Eucalyptus plantings after harvest. Fungi isolates were obtained in a culture medium composed by Eucalyptus sawdust and agar. Among 292 isolates submitted to the Banvedamm test, 144 were classified as phenoloxidases producing isolates. Among nine C

  13. Rhizosphere competent Mesorhizobiumloti MP6 induces root hair curling, inhibits Sclerotinia sclerotiorum and enhances growth of Indian mustard (Brassica campestris)

    National Research Council Canada - National Science Library

    Shikha Chandra; Kamlesh Choure; Ramesh C. Dubey; Dinesh K. Maheshwari

    2007-01-01

    .... loti MP6 in rhizosphere due to root exudates of B. campestris. In dual culture technique the strain showed a strong antagonistic effect against Sclerotinia sclerotiorum, a white rot pathogen of Brassica campestris. The growth of S...

  14. Myxomycetes of the rotting cherry wood

    Directory of Open Access Journals (Sweden)

    Wanda Stojanowska

    2014-08-01

    Full Text Available During the years 1974-1975 on rotting cherry wood development of some Myxomycetes was observed. In that time 6 species of slime molds were noted: Arcyria denudata, Comatricha typhoides, Dyctidium cancellatum, Lycogala epidendrum, Physarum cinereum, Stemonitis ferruginea. In the decomposition of organic compounds apart from Myxomycetes other organism (Coprinus dessiminafus also take part.

  15. Postharvest Rhizopus rot on sugar beet

    Science.gov (United States)

    Rhizopus species have been reported as a minor post-harvest rot on sugar beet, particularly under temperatures above 5 deg C. In 2010, Rhizopus was isolated from beets collected from Michigan storage piles in February at a low frequency. However, recent evidence from Michigan has found a high incide...

  16. Linking fungal communities in roots, rhizosphere, and soil to the health status of Pisum sativum

    DEFF Research Database (Denmark)

    Xu, Lihui; Ravnskov, Sabine; Larsen, John

    2012-01-01

    the three fields identified a number of OTUs that were more abundant in healthy roots. Pathogens such as Fusarium oxysporum were abundant in diseased roots in some fields. Patterns of disease and causal agents of root rot were different among the three fields, which were also reflected in fungal communities...

  17. Isolation of laccase gene-specific sequences from white rot and brown rot fungi by PCR

    Energy Technology Data Exchange (ETDEWEB)

    D`Souza, T.M.; Boominathan, K.; Reddy, C.A. [Michigan State Univ., East Lansing, MI (United States)

    1996-10-01

    Degenerate primers corresponding to the consensus sequences of the copper-binding regions in the N-terminal domains of known basidiomycete laccases were used to isolate laccase gene-specific sequences from strains representing nine genera of wood rot fungi. All except three gave the expected PCR product of about 200 bp. Computer searches of the databases identified the sequences of each of the PCR product of about 200 bp. Computer searches of the databases identified the sequence of each of the PCR products analyzed as a laccase gene sequence, suggesting the specificity of the primers. PCR products of the white rot fungi Ganoderma lucidum, Phlebia brevispora, and Trametes versicolor showed 65 to 74% nucleotide sequence similarity to each other; the similarity in deduced amino acid sequences was 83 to 91%. The PCR products of Lentinula edodes and Lentinus tigrinus, on the other hand, showed relatively low nucleotide and amino acid similarities (58 to 64 and 62 to 81%, respectively); however, these similarities were still much higher than when compared with the corresponding regions in the laccases of the ascomycete fungi Aspergillus nidulans and Neurospora crassa. A few of the white rot fungi, as well as Gloeophyllum trabeum, a brown rot fungus, gave a 144-bp PCR fragment which had a nucleotide sequence similarity of 60 to 71%. Demonstration of laccase activity in G. trabeum and several other brown rot fungi was of particular interest because these organisms were not previously shown to produce laccases. 36 refs., 6 figs., 2 tabs.

  18. Integrated management of foot rot of lentil using biocontrol agents under field condition.

    Science.gov (United States)

    Hannan, M A; Hasan, M M; Hossain, I; Rahman, S M E; Ismail, Alhazmi Mohammed; Oh, Deog-Hwan

    2012-07-01

    The efficacy of cowdung, Bangladesh Institute of Nuclear Agriculture (BINA)-biofertilizer, and Bangladesh Agricultural University (BAU)-biofungicide, alone or in combination, was evaluated for controlling foot rot disease of lentil. The results exhibited that BINA-biofertilizer and BAUbiofungicide (peat soil-based Rhizobium leguminosarum and black gram bran-based Trichoderma harzianum) are compatible and have combined effects in controlling the pathogenic fungi Fusarium oxysporum and Sclerotium rolfsii, which cause the root rot of lentil. Cowdung mixing with soil (at 5 t/ha) during final land preparation and seed coating with BINA-biofertilizer and BAU-biofungicide (at 2.5% of seed weight) before sowing recorded 81.50% field emergence of lentil, which showed up to 19.85% higher field emergence over the control. Post-emergence deaths of plants due to foot rot disease were significantly reduced after combined seed treatment with BINA-biofertilizer and BAU-biofungicide. Among the treatments used, only BAU-biofungicide as the seed treating agent resulted in higher plant stand (84.82%). Use of BINA-biofertilizer and BAU-biofungicide as seed treating biocontrol agents and application of cowdung in the soil as an organic source of nutrient resulted in higher shoot and root lengths, and dry shoot and root weights of lentil. BINA-biofertilizer significantly increased the number of nodules per plant and nodules weight of lentil. Seeds treating with BAUbiofungicide and BINA-biofertilizer and soil amendment with cowdung increased the biomass production of lentil up to 75.56% over the control.

  19. Rot is a key regulator of Staphylococcus aureus biofilm formation

    Science.gov (United States)

    Mootz, Joe M.; Benson, Meredith A.; Heim, Cortney E.; Crosby, Heidi A.; Kavanaugh, Jeffrey S.; Dunman, Paul M.; Kielian, Tammy; Torres, Victor J.; Horswill, Alexander R.

    2015-01-01

    AUTHOR SUMMARY Staphylococcus aureus is a significant cause of chronic biofilm infections on medical implants. We investigated the biofilm regulatory cascade and discovered that the repressor of toxins (Rot) is part of this pathway. A USA300 community-associated methicillin-resistant S. aureus (CA-MRSA) strain deficient in Rot was unable to form a biofilm using multiple different assays, and we found rot mutants in other strain lineages were also biofilm deficient. By performing a global analysis of transcripts and protein production controlled by Rot, we observed that all the secreted protease genes were upregulated in a rot mutant, and we hypothesized that this regulation could be responsible for the biofilm phenotype. To investigate this question, we determined that Rot bound to the protease promoters, and we observed that activity levels of these enzymes, in particular the cysteine proteases, were increased in a rot mutant. By inactivating these proteases, biofilm capacity was restored to the mutant, demonstrating they are responsible for the biofilm negative phenotype. Finally, we tested the rot mutant in a mouse catheter model of biofilm infection and observed a significant reduction in biofilm burden. Thus S. aureus uses the transcription factor Rot to repress secreted protease levels in order to build a biofilm. PMID:25612137

  20. Anchorage of mature conifers: resistive turning moment, root-soil plate geometry and root growth orientation.

    Science.gov (United States)

    Lundström, Tor; Jonas, Tobias; Stöckli, Veronika; Ammann, Walter

    2007-09-01

    Eighty-four mature Norway spruce (Picea abies L. Karst), silver fir (Abies alba Mill) and Scots pine (Pinus sylvestris L.) trees were winched over to determine the maximum resistive turning moment (M(a)) of the root-soil system, the root-soil plate geometry, the azimuthal orientation of root growth, and the occurrence of root rot. The calculation of M(a), based on digital image tracking of stem deflection, accounted not only for the force application and its changing geometry, but also for the weight of the overhanging tree, representing up to 42% of M(a). Root rot reduced M(a) significantly and was detected in 25% of the Norway spruce and 5% of the silver fir trees. Excluding trees with root rot, differences in M(a) between species were small and insignificant. About 75% of the variance in M(a) could be explained by one of the four variables--tree mass, stem mass, stem diameter at breast height squared times tree height, and stem diameter at breast height squared. Among the seven allometric variables assessed above ground, stem diameter at breast height best described the root-soil plate dimensions, but the correlations were weak and the differences between species were insignificant. The shape of the root-soil plate was well described by a depth-dependent taper model with an elliptical cross section. Roots displayed a preferred azimuthal orientation of growth in the axis of prevailing winds, and the direction of frequent weak winds matched the orientation of growth better than that of rare strong winds. The lack of difference in anchorage parameters among species probably reflects the similar belowground growth conditions of the mature trees.

  1. Extensive sampling of basidiomycete genomes demonstrates inadequacy of the white rot/ brown rot paradigm for wood decay fungi

    Energy Technology Data Exchange (ETDEWEB)

    Riley, Robert; Salamov, Asaf; Brown, Daren W.; Nagy, Laszlo G.; Floudas, Dimitris; Held, Benjamin; Levasseur, Anthony; Lombard, Vincent; Morin, Emmanuelle; Otillar, Robert; Lindquist, Erika; Sun, Hui; LaButti, Kurt; Schmutz, Jeremy; Jabbour, Dina; Luo, Hong; Baker, Scott E.; Pisabarro, Antonio; Walton, Jonathan D.; Blanchette, Robert; Henrissat, Bernard; Martin, Francis; Cullen, Dan; Hibbett, David; Grigoriev, Igor V.

    2014-03-14

    Basidiomycota (basidiomycetes) make up 32percent of the described fungi and include most wood decaying species, as well as pathogens and mutualistic symbionts. Wood-decaying basidiomycetes have typically been classified as either white rot or brown rot, based on the ability (in white rot only) to degrade lignin along with cellulose and hemicellulose. Prior genomic comparisons suggested that the two decay modes can be distinguished based on the presence or absence of ligninolytic class II peroxidases (PODs), as well as the abundance of enzymes acting directly on crystalline cellulose (reduced in brown rot). To assess the generality of the white rot/brown rot classification paradigm we compared the genomes of 33 basidiomycetes, including four newly sequenced wood decayers, and performed phylogenetically-informed Principal Components Analysis (PCA) of a broad range of gene families encoding plant biomass-degrading enzymes. The newly sequenced Botryobasidium botryosum and Jaapia argillacea genomes lack PODs, but possess diverse enzymes acting on crystalline cellulose, and they group close to the model white rot species Phanerochaete chrysosporium in the PCA. Furthermore, laboratory assays showed that both B. botryosum and J. argillacea can degrade all polymeric components of woody plant cell walls, a characteristic of white rot. We also found expansions in reducing polyketide synthase genes specific to the brown rot fungi. Our results suggest a continuum rather than a dichotomy between the white rot and brown rot modes of wood decay. A more nuanced categorization of rot types is needed, based on an improved understanding of the genomics and biochemistry of wood decay.

  2. Linking fungal communities in roots, rhizosphere, and soil to the health status of Pisum sativum

    DEFF Research Database (Denmark)

    Xu, Lihui; Ravnskov, Sabine; Larsen, John;

    2012-01-01

    the three fields identified a number of OTUs that were more abundant in healthy roots. Pathogens such as Fusarium oxysporum were abundant in diseased roots in some fields. Patterns of disease and causal agents of root rot were different among the three fields, which were also reflected in fungal communities......Changes in fungal communities associated with healthy and diseased pea roots were investigated using deep amplicon pyrosequencing in three spatial compartments: roots, rhizosphere, and surrounding soil. Thirty root systems were collected from three fields, half of which showing clear symptoms...... of root rot. In total, 500 461 internal transcribed spacer-1 sequences were obtained that were clustered into 123 (roots), 271 (rhizosphere), and 440 (bulk soil) nonsingleton operational taxonomic units (OTUs). Species richness was highest in bulk soils and lowest in roots; however, no notable differences...

  3. Evaluation of soybean genotypes for resistance to charcoal rot

    Science.gov (United States)

    Charcoal rot caused by Macrophomina phaseolina causes more yield loss in soybean than most other diseases in the southern U.S.A. There are no commercial genotypes marketed as resistant to charcoal rot of soybean. Reactions of 27 maturity group (MG) III, 29 Early MG IV, 34 Late MG IV, and 59 MG V gen...

  4. RotCFD Software Validation - Computational and Experimental Data Comparison

    Science.gov (United States)

    Fernandez, Ovidio Montalvo

    2014-01-01

    RotCFD is a software intended to ease the design of NextGen rotorcraft. Since RotCFD is a new software still in the development process, the results need to be validated to determine the software's accuracy. The purpose of the present document is to explain one of the approaches to accomplish that goal.

  5. Thermal control of some post-harvest rot pathogens of Irish potato (solanum tuberosum l.

    Directory of Open Access Journals (Sweden)

    Salami Olusola Abiodun

    2007-01-01

    Full Text Available Thermal control effect on the incidence of some post-harvest rot pathogens of Solanum tuberosum (potato was investigated in this study. Three cultivars of potato tuber whose local names are, Patiska, Mai Bawondoya and Nicola were used for the study. Five pathogenic fungi viz: Botryodiplodia theobromae, Fusarium redolens, Fusarium oxysporum, Penicillium sp. and Rhizopus oryzae associated with post harvest storage rot of root-tubers, were isolated from diseased potatoes. Among the three species of potatoes used in the study, Patiska was found most resistant followed by Mai Bawondoya, while Nicola was the least resistant. Increase in substrate (i.e. soluble starch or CMC concentration enhanced a proportional increase in mycelial growth and in the amount of extracellular enzymes produced. Some of these test pathogens were found to produce cell wall degrading enzymes (i.e. amylase and cellulase. Preferential utilization of carbohydrate sources was established in this study based on the growth of test pathogens. Growth on potato broth medium was highest followed by growth on Cocoyam and Sweet potato broth media and least on Cassava broth medium. Growth of the test pathogens on carbohydrate sources was found at variant. The use of hot water treatment at different temperatures was found to significantly reduce post-harvest fungal populations on the surface of root-tubers. The efficacy of blanching in hot water at 60˚C was significantly higher than that of blanching in hot water at other temperatures. The control method adopted in this study showed that the problems of potatoes’ rot disease in storage (especially by the peasant farmers can be eradicated by thermal treatments without reducing the quality of the Irish tuber.

  6. Biocontrol mechanisms of Trichoderma harzianum against soybean charcoal rot caused by Macrophomina phaseolina

    Directory of Open Access Journals (Sweden)

    Khaledi Nima

    2016-01-01

    Full Text Available Throughout the world, charcoal rot, caused by Macrophomina phaseolina, is one of the most destructive and widespread diseases of crop plants such as soybean. In this study, the biological control capability of 11 Trichoderma spp. isolates against M. phaseolina was investigated using screening tests. Among all the tested Trichoderma spp. isolates, inhibition varied from 20.22 to 58.67% in dual culture tests. Dual culture, volatile and non-volatile tests revealed that two isolates of Trichoderma harzianum (including the isolates T7 and T14 best inhibited the growth of M. phaseolina in vitro. Therefore, these isolates were selected for biocontrol of M. phaseolina in vivo. The results of greenhouse experiments revealed that disease severity in the seed treatment with T. harzianum isolates was significantly lower than that of the soil treatment. In most of the cases, though, soil treatment with T. harzianum resulted in higher plant growth parameters, such as root and shoot weight. The effects of T. harzianum isolates on the activity of peroxidase enzyme and phenolic contents of the soybean root in the presence and absence of M. phaseolina were determined in greenhouse conditions. Our results suggested that a part of the inhibitory effect of T. harzianum isolates on soybean charcoal rot might be related to the indirect influence on M. phaseolina. Plant defense responses were activated as an elicitor in addition to the direct effect on the pathogen growth.

  7. Jasmonic acid causes short- and long-term alterations to the transcriptome and the expression of defense genes in sugarbeet roots

    Science.gov (United States)

    Jasmonic acid (JA) induces native defense responses in plants and increases the resistance of postharvest sugarbeet roots to three common storage-rot causing organisms. To gain insight into the defense responses induced by JA in harvested sugarbeet roots, RNA was isolated from roots treated with wat...

  8. Prevalence of Erwinia soft rot affecting cut foliage, Dracaena sanderiana ornamental industry and solution towards its management.

    Science.gov (United States)

    Kayalvily, Thio Desiya; Jegathambigai, V; Karunarathne, M D S D; Svinningen, Arne; Mikunthan, G

    2012-01-01

    The study was carried out under net house conditions at Green Farms Ltd, Marawila to determine the occurrence and severity of Erwinia soft rot disease in Dracaena sanderiana plants and to formulate the possible control measures. Field experiment was carried out to manage the soft rot disease in D. sanderiana plants. Three different soil treatments with vermicompost, cow dung and poultry manure were tested to manage the disease and plots without application were kept as control. Percent disease incidence, disease reduction and growth parameters were recorded and data were statistically analyzed. Higher percentage of disease reduction was observed in vermicompost (80%) treated plots than those with cow dung (60%) and poultry manure treated. Sprinkler application of water was found favorable to spread soft rot disease and watering through horse pope had lessened the disease incidence significantly. Moreover plant height, shoot and root biomass, number of leaves per plant, leaf length and leaf width were significantly high in vermicompost media. Weeding, removal of diseased leaves and plants, and avoiding sprinkler irrigation were helpful to reduce the disease spread from plant to plant. Vermicompost is the best substrate for suppression of the disease and promoting the growth of plant. Among the different water management practices tested to reduce the disease severity of Erwinia soft rot disease in D. sanderiana plants, water irrigated through the horse pipe was effective compare to sprinkler application. In-vitro experiment conducted to manage the Erwinia soft rot disease by using bio-agent, Pseudomonas fluorescens was found effective to reduce the growth of Erwinia under in-vitro conditions.

  9. Effect of seed pelleting with biocontrol agents on growth and colonisation of roots of mungbean by root-infecting fungi.

    Science.gov (United States)

    Ramzan, Nadia; Noreen, Nayara; Perveen, Zahida; Shahzad, Saleem

    2016-08-01

    Mungbean (Vigna radiata (L.) Wilczek) is a leguminous pulse crop that is a major source of proteins, vitamins and minerals. Root-infecting fungi produce severe plant diseases like root rot, charcoal rot, damping-off and stem rot. The soil-borne pathogens can be controlled by chemicals, but these chemicals have several negative effects. Use of microbial antagonist such as fungi and bacteria is a safe, effective and eco-friendly method for the control of many soil-borne pathogens. Biological control agents promote plant growth and develop disease resistance. Application of bacteria and fungi as seed dressing suppressed the root-infecting fungi on leguminous crops. Seeds of mungbean were pelleted with different biocontrol agents to determine their effect on plant growth and colonisation of roots by root-infecting fungi, viz. Fusarium solani, Macrophomina phaseolina, Pythium aphanidermatum, Rhizoctonia solani and Sclerotium rolfsii. Treatment of mungbean seeds with fungal antagonists showed more shoot and root length as compared to bacterial antagonists, whereas seed treated with bacterial antagonists showed maximum shoot and root weight. Trichoderma harzianum and Bacillus subtilis were the best among all the biocontrol agents since they provided the highest plant growth and greater reduction in root colonisation by all root-infecting fungi. Bacillus cereus, Trichoderma virens, Pseudomonas fluorescens and Micrococcus varians were also effective against root-infecting fungi but to a lesser extent. T. harzianum, T. virens, B. subtilis and P. fluorescens were found to be best among all biocontrol agents. The root-infecting fungi can be controlled by pelleting seeds with biocontrol agents as it is safe and effective method. Additionally, plant growth was promoted more by this method. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  10. GammaScorpion: mobile gamma-ray tomography system for early detection of basal stem rot in oil palm plantations

    Science.gov (United States)

    Abdullah, Jaafar; Hassan, Hearie; Shari, Mohamad Rabaie; Mohd, Salzali; Mustapha, Mahadi; Mahmood, Airwan Affendi; Jamaludin, Shahrizan; Ngah, Mohd Rosdi; Hamid, Noor Hisham

    2013-03-01

    Detection of the oil palm stem rot disease Ganoderma is a major issue in estate management and production in Malaysia. Conventional diagnostic techniques are difficult and time consuming when using visual inspection, and destructive and expensive when based on the chemical analysis of root or stem tissue. As an alternative, a transportable gamma-ray computed tomography system for the early detection of basal stem rot (BSR) of oil palms due to Ganoderma was developed locally at the Malaysian Nuclear Agency, Kajang, Malaysia. This system produces high quality tomographic images that clearly differentiate between healthy and Ganoderma infected oil palm stems. It has been successfully tested and used to detect the extent of BSR damage in oil palm plantations in Malaysia without the need to cut down the trees. This method offers promise for in situ inspection of oil palm stem diseases compared to the more conventional methods.

  11. EXTRACELLULAR POLYSACCHARIDES OF POTATO RING ROT PATHOGEN

    Directory of Open Access Journals (Sweden)

    Shafikova Т.N.

    2006-03-01

    Full Text Available Many bacteria, including phytopathogenic ones produce extracellular polysaccharides or exopolysaccharides which are universal molecules. Causal agent of potato ring rot, Clavibacter michiganensis subspecies sepedonicus, secretes exopolysaccharides which role in pathogenesis is poorly investigated. The aim of our research is to ascertain the composition and structure of Clavibacter michiganensis subspecies sepedonicus exopolysaccharides. Exopolysaccharides of Clavibacter michiganensis subspecies sepedonicus are determined to consist of 4-6 anionic and neutral components which have molecular weights from 700 kDa. Glucose is a major monomer of polysaccharides and arabinose, rhamnose and mannose are minor monomers. Glucose is present in α-Dglucopyranose and β-D-glucopyranose configurations. Calcium is determined to be a component of exopolysaccharides. Components of exopolysaccharides of potato ring rot pathogen are probably capableto associate via calcium ions and other ionic interactions that may result in a change of their physiological activity. Further studies of Clavibacter michiganensis subspecies sepedonicus exopolysaccharides composition and structure can serve a base for the synthesis of their chemical analogues with elicitor action.

  12. Co-inoculation with rhizobia and AMF inhibited soybean red crown rot: from field study to plant defense-related gene expression analysis.

    Directory of Open Access Journals (Sweden)

    Xiang Gao

    Full Text Available BACKGROUND: Soybean red crown rot is a major soil-borne disease all over the world, which severely affects soybean production. Efficient and sustainable methods are strongly desired to control the soil-borne diseases. PRINCIPAL FINDINGS: We firstly investigated the disease incidence and index of soybean red crown rot under different phosphorus (P additions in field and found that the natural inoculation of rhizobia and arbuscular mycorrhizal fungi (AMF could affect soybean red crown rot, particularly without P addition. Further studies in sand culture experiments showed that inoculation with rhizobia or AMF significantly decreased severity and incidence of soybean red crown rot, especially for co-inoculation with rhizobia and AMF at low P. The root colony forming unit (CFU decreased over 50% when inoculated by rhizobia and/or AMF at low P. However, P addition only enhanced CFU when inoculated with AMF. Furthermore, root exudates of soybean inoculated with rhizobia and/or AMF significantly inhibited pathogen growth and reproduction. Quantitative RT-PCR results indicated that the transcripts of the most tested pathogen defense-related (PR genes in roots were significantly increased by rhizobium and/or AMF inoculation. Among them, PR2, PR3, PR4 and PR10 reached the highest level with co-inoculation of rhizobium and AMF. CONCLUSIONS: Our results indicated that inoculation with rhizobia and AMF could directly inhibit pathogen growth and reproduction, and activate the plant overall defense system through increasing PR gene expressions. Combined with optimal P fertilization, inoculation with rhizobia and AMF could be considered as an efficient method to control soybean red crown rot in acid soils.

  13. Root hairs

    NARCIS (Netherlands)

    Grierson, C.; Nielsen, E.; Ketelaar, T.; Schiefelbein, J.

    2014-01-01

    Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair

  14. Management of Fusarium corm rot of gladiolus (Gladiolus ...

    African Journals Online (AJOL)

    USER

    2010-07-26

    Jul 26, 2010 ... Developing disease suppressive soils by introducing allelopathic crop residue manage- ment takes time, but the benefits accumulate across ..... crop rotation on corm rots disease of Gladiolus. Sci. Hortic. 121: 218-222 ...

  15. Autochthonous white rot fungi from the tropical forest: Potential of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... Autochthonous white rot fungi from the tropical forest: Potential of Cuban ... organo-pollutants structurally similar to lignin (Pointing,. 2001). It has also ..... potentially have a positive action against complex pollution situations.

  16. Evaluation of bacteria isolated from rice rhizosphere for biological control of charcoal rot of sorghum caused by Macrophomina phaseolina (Tassi) Goid.

    Science.gov (United States)

    Gopalakrishnan, Subramaniam; Humayun, Pagidi; Kiran, Bandru Keerthi; Kannan, Iyer Girish Kumar; Vidya, Meesala Sree; Deepthi, Kanala; Rupela, Om

    2011-06-01

    A total of 360 bacteria, isolated from the rhizospheres of a system of rice intensification (SRI) fields, were characterized for the production of siderophore, fluorescence, indole acetic acid (IAA), hydrocyanic acid (HCN) and solubilization of phosphorus. Of them, seven most promising isolates (SRI-156, -158, -178, -211, -229, -305 and -360) were screened for their antagonistic potential against Macrophomina phaseolina (causes charcoal rot in sorghum) by dual culture assay, blotter paper assay and in greenhouse. All the seven isolates inhibited M. phaseolina in dual culture assay, whereas six isolates solubilized phosphorous (except SRI-360), all seven produced siderophore, four produced fluorescence (except SRI-178, -229 and -305), six produced IAA (except SRI-305) and five produced HCN (except SRI-158 and -305). In the blotter paper assay, no charcoal rot infection was observed in SRI-156-treated sorghum roots, indicating complete inhibition of the pathogen, while the roots treated with the other isolates showed 49-76% lesser charcoal rot infection compared to the control. In the antifungal activity test (in green house on sorghum), all the isolates increased shoot dry mass by 15-23% and root dry mass by 15-20% (except SRI-158 and -360), over the control. In order to confirm the plant growth-promoting (PGP) traits of the isolates, the green house experiment was repeated but, in the absence of M. phaseolina. The results further confirmed the PGP traits of the isolates as evidenced by increases in shoot and root dry mass, 22-100% and 5-20%, respectively, over the control. The sequences of 16S rDNA gene of the isolates SRI-156, -158, -178, -211, -229, -305 and -360 were matched with Pseudomonas plecoglossicida, Brevibacterium antiquum, Bacillus altitudinis, Enterobacter ludwigii, E. ludwigii, Acinetobacter tandoii and P. monteilii, respectively in BLAST analysis. This study indicates that the selected bacterial isolates have the potential for PGP and control of

  17. Comparative studies on thermochemical characterization of corn stover pretreated by white-rot and brown-rot fungi.

    Science.gov (United States)

    Zeng, Yelin; Yang, Xuewei; Yu, Hongbo; Zhang, Xiaoyu; Ma, Fuying

    2011-09-28

    The effects of white-rot and brown-rot fungal pretreatment on the chemical composition and thermochemical conversion of corn stover were investigated. Fungus-pretreated corn stover was analyzed by Fourier transform infrared spectroscopy and X-ray diffraction analysis to characterize the changes in chemical composition. Differences in thermochemical conversion of corn stover after fungal pretreatment were investigated using thermogravimetric and pyrolysis analysis. The results indicated that the white-rot fungus Irpex lacteus CD2 has great lignin-degrading ability, whereas the brown-rot fungus Fomitopsis sp. IMER2 preferentially degrades the amorphous regions of the cellulose. The biopretreatment favors thermal decomposition of corn stover. The weight loss of IMER2-treated acid detergent fiber became greater, and the oil yield increased from 32.7 to 50.8%. After CD2 biopretreatment, 58% weight loss of acid detergent lignin was achieved and the oil yield increased from 16.8 to 26.8%.

  18. Evaluation of natural plant extracts, antagonists and fungicides in controlling root rot, collar rot, fruit (brown rot and gummosis of citrus caused by Phytophthora spp. in vitro

    Directory of Open Access Journals (Sweden)

    G.P. Jagtap

    2012-07-01

    Full Text Available The results revealed that all the six bioagents tested in vitro applying dual culture technique against Phytophthora nicotianae, Phytophthora citrophthora and Phytophthora palmivora significantly inhibited the mycelial growth of the test pathogen over untreated control. However, bioagent, Trichoderma harzianum recorded minimum mean colony diameter (7.73 cm2 and highest inhibition (87.85% of mycelial growth of P. nicotianae over untreated control followed by the bioagent T. viride, T. koningii which recorded mean colony diameter of 9.95 cm2, 14.15 cm2 and mean mycelial inhibition of 84.36 %, 77.76%, respectively. Evaluation of different botanicals by Poisoned Food Technique showed that all plant extracts tested in vitro were found significantly effective in reducing the percentage mycelial growth of P. nicotianae, P. citrophthora and P. palmivora over untreated control. However, plant extract (@ 5, 10 and 15% of Garlic, recorded lowest mean colony diameter (47.45 mm and highest mean mycelial growth inhibition (47.26% followed by Neem, Onion which recorded the mycelial growth of 55.20 mm, 60.85 mm, and the mean mycelial growth inhibition of 38.65%, 32.38%, respectively. Results revealed that all the nine fungicides tested in vitro applying Poisoned Food Technique against P. nicotianae, P. citrophthora and P. palmivora significantly inhibited the mycelial growth of the test pathogen over untreated control. However, fungicide, Cymoxynil 8% + Mancozeb 64% (Curzate M-8 recorded minimum mean colony diameter (16.12 mm and maximum mean inhibition (82.09% of mycelial growth of the test pathogen over untreated control (mean colony diameter 90.00 mm and mean inhibition 0.00 followed by the fungicide Metalaxyl-M 4% + Mancozeb 64% (Ridomil Gold, Metyram (Polyram, which recorded mean colony diameter of 20.16 mm, 24.16 mm and mean mycelial inhibition of 77.59%, 73.14%, respectively.

  19. Identification and Pathogenicity of Phytopathogenic Bacteria Associated with Soft Rot Disease of Girasole Tuber

    Directory of Open Access Journals (Sweden)

    Mamdoh Ewis ISMAIL

    2012-02-01

    Full Text Available During 2010-2011 growing seasons six bacterial isolates were separated from naturally infected girasole plants tubers (Helianthus tuberosus L. cv. Balady, showing soft rot, collected from experimental Farm of the Faculty of Agriculture, in El-Minia University, Egypt. Pathogenicity tests showed various virulence for the bacteria isolated from girasole tubers, found pathogenic. These organisms were characterized as rod-shaped, Gram negative, ?-methyl-d-glucoside medium, reducing substances from sucrose, phos, phatase activity and deep cavities on pectate medium. Otherwise, diagnostic tests suggested that the pathogen was Erwinia carotovora ssp. carotovora. The isolated bacteria caused soft rot of wounded tubers when inoculated into tissues. The bacterial isolates were compared for their degree of pathogenicity as well as for differences in specific symptoms, induced in different hosts. The tested isolates could infect several host ranges, such as fruits of apricot, apple, olive, lemon, squash, eggplant and potato tubers, bulbs and garlic and onion cloves, roots radish, carrot, sweet potato and rape. On the other hand, no symptoms were exhibited on pods of bean and cowpea, faba bean, fruits of pepper and tomato. The extracts of experimentally diseased girasole tubers were active in pectinase and also in caboxymethyl cellulose at pH 6 compared to enzyme activities in healthy tissues. Also, the isolated bacteria increased the total and reducing sugars in infected tissues.

  20. Identification and Pathogenicity of Phytopathogenic Bacteria Associated with Soft Rot Disease of Girasole Tuber

    Directory of Open Access Journals (Sweden)

    Mamdoh Ewis ISMAIL

    2012-02-01

    Full Text Available During 2010-2011 growing seasons six bacterial isolates were separated from naturally infected girasole plants tubers (Helianthus tuberosus L. cv. �Balady�, showing soft rot, collected from experimental Farm of the Faculty of Agriculture, in El-Minia University, Egypt. Pathogenicity tests showed various virulence for the bacteria isolated from girasole tubers, found pathogenic. These organisms were characterized as rod-shaped, Gram negative, ?-methyl-d-glucoside medium, reducing substances from sucrose, phos, phatase activity and deep cavities on pectate medium. Otherwise, diagnostic tests suggested that the pathogen was Erwinia carotovora ssp. carotovora. The isolated bacteria caused soft rot of wounded tubers when inoculated into tissues. The bacterial isolates were compared for their degree of pathogenicity as well as for differences in specific symptoms, induced in different hosts. The tested isolates could infect several host ranges, such as fruits of apricot, apple, olive, lemon, squash, eggplant and potato tubers, bulbs and garlic and onion cloves, roots radish, carrot, sweet potato and rape. On the other hand, no symptoms were exhibited on pods of bean and cowpea, faba bean, fruits of pepper and tomato. The extracts of experimentally diseased girasole tubers were active in pectinase and also in caboxymethyl cellulose at pH 6 compared to enzyme activities in healthy tissues. Also, the isolated bacteria increased the total and reducing sugars in infected tissues.

  1. Response of cultivars of malanga (Xanthosoma sagittifolium (L. Schott to dry rot

    Directory of Open Access Journals (Sweden)

    Ernesto Espinosa Cuéllar

    2017-01-01

    Full Text Available Malanga (Xanthosoma sagittifolium (L. Schott is an important food crop for over 400 million people in the tropics and subtropics. In order to determine the response of different varieties of malanga Xanthosoma to dry rot, a series of experiments were conducted in the period between 2012 and 2014. The experiments were performed on loamy Soil at the National Research Institute in Tropical Crops and Roots (INIVIT. We determined the incidence and severity of damage, yields and percent of losses at harvest. The lowest values of incidence and the highest total return was achieved in clons ‘INIVIT MX-95-2’, ‘INIVIT MX-95-1’ and ‘INIVIT MX-2007’. Clones of malanga Xanthosoma belonging to the group purple, showed lower incidence that of white and yellow groups. These results will allow selecting cultivars of malanga with greater resistance to the dry rot and with this to diminish the losses in the harvest.

  2. QTLs for Resistance to Major Rice Diseases Exacerbated by Global Warming: Brown Spot, Bacterial Seedling Rot, and Bacterial Grain Rot.

    Science.gov (United States)

    Mizobuchi, Ritsuko; Fukuoka, Shuichi; Tsushima, Seiya; Yano, Masahiro; Sato, Hiroyuki

    2016-12-01

    In rice (Oryza sativa L.), damage from diseases such as brown spot, caused by Bipolaris oryzae, and bacterial seedling rot and bacterial grain rot, caused by Burkholderia glumae, has increased under global warming because the optimal temperature ranges for growth of these pathogens are relatively high (around 30 °C). Therefore, the need for cultivars carrying genes for resistance to these diseases is increasing to ensure sustainable rice production. In contrast to the situation for other important rice diseases such as blast and bacterial blight, no genes for complete resistance to brown spot, bacterial seedling rot or bacterial grain rot have yet been discovered. Thus, rice breeders have to use partial resistance, which is largely influenced by environmental conditions. Recent progress in molecular genetics and improvement of evaluation methods for disease resistance have facilitated detection of quantitative trait loci (QTLs) associated with resistance. In this review, we summarize the results of worldwide screening for cultivars with resistance to brown spot, bacterial seedling rot and bacterial grain rot and we discuss the identification of QTLs conferring resistance to these diseases in order to provide useful information for rice breeding programs.

  3. Root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed.......The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed....

  4. Repression of hla by rot is dependent on sae in Staphylococcus aureus.

    Science.gov (United States)

    Li, Dongmei; Cheung, Ambrose

    2008-03-01

    The regulatory locus sae is a two-component system in Staphylococcus aureus that regulates many important virulence factors, including alpha-toxin (encoded by hla) at the transcriptional level. The SarA homologs Rot and SarT were previously shown to be repressors of hla in selected S. aureus backgrounds. To delineate the interaction of rot and sae and the contribution of sarT to hla expression, an assortment of rot and sae isogenic single mutants, a rot sae double mutant, and a rot sae sarT markerless triple mutant were constructed from wild-type strain COL. Using Northern blot analysis and transcriptional reporter gene green fluorescent protein, fusion, and phenotypic assays, we found that the repression of hla by rot is dependent on sae. A rot sae sarT triple mutant was not able to rescue the hla defect of the rot sae double mutant. Among the three sae promoters, the distal sae P3 promoter is the strongest in vitro. Interestingly, the sae P3 promoter activities correlate with hla expression in rot, rot sae, and rot sae sarT mutants of COL. Transcriptional study has also shown that rot repressed sae, especially at the sae P3 promoter. Collectively, our data implicated the importance of sae in the rot-mediated repression of hla in S. aureus.

  5. High-throughput sequencing of black pepper root transcriptome

    Directory of Open Access Journals (Sweden)

    Gordo Sheila MC

    2012-09-01

    Full Text Available Abstract Background Black pepper (Piper nigrum L. is one of the most popular spices in the world. It is used in cooking and the preservation of food and even has medicinal properties. Losses in production from disease are a major limitation in the culture of this crop. The major diseases are root rot and foot rot, which are results of root infection by Fusarium solani and Phytophtora capsici, respectively. Understanding the molecular interaction between the pathogens and the host’s root region is important for obtaining resistant cultivars by biotechnological breeding. Genetic and molecular data for this species, though, are limited. In this paper, RNA-Seq technology has been employed, for the first time, to describe the root transcriptome of black pepper. Results The root transcriptome of black pepper was sequenced by the NGS SOLiD platform and assembled using the multiple-k method. Blast2Go and orthoMCL methods were used to annotate 10338 unigenes. The 4472 predicted proteins showed about 52% homology with the Arabidopsis proteome. Two root proteomes identified 615 proteins, which seem to define the plant’s root pattern. Simple-sequence repeats were identified that may be useful in studies of genetic diversity and may have applications in biotechnology and ecology. Conclusions This dataset of 10338 unigenes is crucially important for the biotechnological breeding of black pepper and the ecogenomics of the Magnoliids, a major group of basal angiosperms.

  6. Maize Stalk Rot and Ear Rot in China%中国玉米茎基腐病和穗腐病研究进展

    Institute of Scientific and Technical Information of China (English)

    徐书法; 陈捷; 高增贵; 邹庆道; 纪明山; 刘海南

    2006-01-01

    This review provides a broad overview of etiology, mechanism of pathogenesis and host resistance and IPM strategies involved in maize stalk rot and ear rot diseases in China. Some different viewpoints in the past are discussed in etiology of stalk rot occurring in China. The relation of both diseases is particularly evaluated based on Fusarium polymorphism analysis at the level of soluble protein, serology, isozymes and DNA, which are also further analyzed in accordance with the knowledge obtained by tracing pathogen infection process within the host root and stem tissue and trapping airborne spores nearby corn plants in the field. The recent researches of both diseases are summarized in physiological and biochemical mechanism of host resistance and resistant genetics, as well as IPM measures centered mainly in the application of biological control agents are summarized.%本文综述了我国在玉米茎基腐病和穗腐病病原学、致病性和寄主抗性机制与综合治理的研究进展.深入探讨了以往我国学者关于引起茎基腐病病原学的不同观点.根据2种病害的病原镰孢菌在可溶性蛋白质、血清学、同功酶和DNA等不同水平的多态性分析,镰孢菌在寄主根和茎组织内侵染过程示踪和孢子捕捉试验结果,重点讨论了2种镰孢菌病害在病原学侵染规律方面的相互关系,概述了2种病害寄主抗性生理生化机理、抗性遗传和以生物防治为核心的综合治理措施研究进展.

  7. Control of storage rot by induction of plant defense mechanisms using jasmonic acid and salicylic acid

    Science.gov (United States)

    Storage rots contribute to sugarbeet postharvest losses by consuming sucrose and producing carbohydrate impurities that increase sugar loss to molasses. Presently, storage rots are controlled by cooling storage piles. This method of control, however, requires favorable weather conditions for stora...

  8. Reaction of Cauliflower Genotypes to Black Rot of Crucifers

    Science.gov (United States)

    da Silva, Lincon Rafael; da Silva, Renan César Dias; Cardoso, Atalita Francis; de Mello Pelá, Gláucia; Carvalho, Daniel Diego Costa

    2015-01-01

    This study aimed to evaluate six cauliflower genotypes regarding their resistance to black rot and their production performance. To do so, it was conducted two field experiments in Ipameri, Goiás, Brazil, in 2012 and 2013. It was used a randomized block design, with four replications (total of 24 plots). Each plot consisted of three planting lines 2.5 m long (six plants/line), spaced 1.0 m apart, for a total area of 7.5 m2. Evaluations of black rot severity were performed at 45 days after transplanting, this is, 75 days after sowing (DAS), and yield evaluations at 90 to 105 DAS. The Verona 184 genotype was the most resistant to black rot, showing 1.87 and 2.25% of leaf area covered by black rot symptom (LACBRS) in 2012 and 2013. However, it was not among the most productive materials. The yield of the genotypes varied between 15.14 and 25.83 t/ha in both years, Lisvera F1 (21.78 and 24.60 t/ha) and Cindy (19.95 and 23.56 t/ha) being the most productive. However, Lisvera F1 showed 6.37 and 9.37% of LACBRS and Cindy showed 14.25 and 14.87% of LACBRS in 2012 and 2013, being both considered as tolerant to black rot. PMID:26060437

  9. Reaction of Cauliflower Genotypes to Black Rot of Crucifers

    Directory of Open Access Journals (Sweden)

    Lincon Rafael da Silva

    2015-06-01

    Full Text Available This study aimed to evaluate six cauliflower genotypes regarding their resistance to black rot and their production performance. To do so, it was conducted two field experiments in Ipameri, Goiás, Brazil, in 2012 and 2013. It was used a randomized block design, with four replications (total of 24 plots. Each plot consisted of three planting lines 2.5 m long (six plants/line, spaced 1.0 m apart, for a total area of 7.5 m². Evaluations of black rot severity were performed at 45 days after transplanting, this is, 75 days after sowing (DAS, and yield evaluations at 90 to 105 DAS. The Verona 184 genotype was the most resistant to black rot, showing 1.87 and 2.25% of leaf area covered by black rot symptom (LACBRS in 2012 and 2013. However, it was not among the most productive materials. The yield of the genotypes varied between 15.14 and 25.83 t/ha in both years, Lisvera F1 (21.78 and 24.60 t/ha and Cindy (19.95 and 23.56 t/ha being the most productive. However, Lisvera F1 showed 6.37 and 9.37% of LACBRS and Cindy showed 14.25 and 14.87% of LACBRS in 2012 and 2013, being both considered as tolerant to black rot.

  10. ROTS: An R package for reproducibility-optimized statistical testing.

    Science.gov (United States)

    Suomi, Tomi; Seyednasrollah, Fatemeh; Jaakkola, Maria K; Faux, Thomas; Elo, Laura L

    2017-05-01

    Differential expression analysis is one of the most common types of analyses performed on various biological data (e.g. RNA-seq or mass spectrometry proteomics). It is the process that detects features, such as genes or proteins, showing statistically significant differences between the sample groups under comparison. A major challenge in the analysis is the choice of an appropriate test statistic, as different statistics have been shown to perform well in different datasets. To this end, the reproducibility-optimized test statistic (ROTS) adjusts a modified t-statistic according to the inherent properties of the data and provides a ranking of the features based on their statistical evidence for differential expression between two groups. ROTS has already been successfully applied in a range of different studies from transcriptomics to proteomics, showing competitive performance against other state-of-the-art methods. To promote its widespread use, we introduce here a Bioconductor R package for performing ROTS analysis conveniently on different types of omics data. To illustrate the benefits of ROTS in various applications, we present three case studies, involving proteomics and RNA-seq data from public repositories, including both bulk and single cell data. The package is freely available from Bioconductor (https://www.bioconductor.org/packages/ROTS).

  11. DEGRADATION OF TEXTILE DYES BY WHITE ROT BASIDIOMYCETES

    Directory of Open Access Journals (Sweden)

    B.P. PARMAR, P.N. MERVANA B.R.M. VYAS*

    2014-12-01

    Full Text Available ABSTRACT: Dyes released by the textile industries pose a threat to environmental quality. Ligninolytic white-rot basidiomycetes can effectively degrade colored effluents and conventional dyes. White-rot fungi produce various isoforms of extracellular oxidases including laccase, Mn peroxidase and lignin peroxidase (LiP, which are involved in the degradation of lignin in their natural lignocellulosic substrates.  The textile industry, by far the most avid user of synthetic dyes, is in need of eco-efficient solutions for its colored effluents. White rot basidiomycetous fungi comprise the only group of organisms known to completely degrade lignin. Ligninolytic enzymes have potential applications in a large number of fields, including the chemical, fuel, food, agricultural, paper, textile, cosmetic industrial sectors and more. This ligninolytic system of white-rot fungi is also directly involved in the degradation of various xenobiotic compounds apart from textile dyes. Their capacities to remove xenobiotic substances make them a useful tool for bioremediation purposes. This paper reviews involvement of ligninolytic enzymes of white rot basidiomycetes in the degradation of textiles dyes and xenobiotic compounds for their industrial and biotechnological applications.

  12. Genetic variation between Phytophthora cactorum isolates differing in their ability to cause crown rot in strawberry

    NARCIS (Netherlands)

    Eikemo, H.; Klemsdal, S.S.; Riisberg, I.; Bonants, P.J.M.; Stensvand, A.; Tronsmo, A.M.

    2004-01-01

    Analysis of 44 isolates of Phytophthora cactorum, isolated from strawberry and other hosts, by AFLP showed that the crown rot pathotype is different from leather rot isolates and from P. cactorum isolated from other hosts. 16 of 23 crown rot isolates, including isolates from Europe, Japan, Australia

  13. Genetic variation between Phytophthora cactorum isolates differing in their ability to cause crown rot in strawberry

    NARCIS (Netherlands)

    Eikemo, H.; Klemsdal, S.S.; Riisberg, I.; Bonants, P.J.M.; Stensvand, A.; Tronsmo, A.M.

    2004-01-01

    Analysis of 44 isolates of Phytophthora cactorum, isolated from strawberry and other hosts, by AFLP showed that the crown rot pathotype is different from leather rot isolates and from P. cactorum isolated from other hosts. 16 of 23 crown rot isolates, including isolates from Europe, Japan, Australia

  14. Black rot of cabbage in The Netherlands: studies on spatial and temporal development.

    NARCIS (Netherlands)

    Kocks, C.G.

    1998-01-01

    Black rot in cabbage is caused by the bacterium Xanthomonas campestris pv. campestris . An exploratory survey at farm level suggested that major aspects contributing to black rot development are cultivar, initial inoculum, refuse management, origin of transplants, and seed quality. Black rot develop

  15. Biological Control of Phacidiopycnis Rot in ‘d’Anjou’ Pears

    Science.gov (United States)

    Phacidiopycnis rot, caused by Phacidiopycnis piri, is a recently reported postharvest fruit rot disease of pears (Pyrus) in the U.S. and a major disease of ‘d’Anjou’ pears grown in Washington State. Phacidiopycnis rot can originate from infection of wounds on the fruit. In this study, two biocontrol...

  16. Impacts of fungal stalk rot pathogens on physicochemical properties of sorghum grain

    Science.gov (United States)

    Stalk rot diseases are among the most ubiquitous and damaging fungal diseases of sorghum worldwide. Although reports of quantitative stalk rot yield losses are available, the impact of stalk rot on the physicochemical attributes of sorghum grain is currently unknown. This study was conducted to test...

  17. Bacillus seed and boll rot of cotton: Symptoms and transmission by Hemiptera

    Science.gov (United States)

    Bolls affected by seed rot and internal boll rot were sampled from various geographical areas over three years and examined for organisms capable of causing disease. After Pantoea species and Nematospora coryli, Bacillus species were one of the microorganisms often associated with seed and boll rot...

  18. The use of white-rot fungi as active biofilters

    Energy Technology Data Exchange (ETDEWEB)

    Braun-Luellemann, A.; Johannes, C.; Majcherczyk, A.; Huettermann, A. [Univ. Goettingen (Germany). Forstbotanisches Inst.

    1995-12-31

    White-rot fungi, growing on lignocellulosic substrates, have been successfully used as active organisms in biofilters. Filters using these fungi have a very high biological active surface area, allowing for high degrees of retention, a comparatively low pressure drop, and a high physical stability. The unspecific action of the extracellular enzymes of the white-rot fungi allows for the degradation of a wide variety of substances by the same organism. Degradation of several compounds in the gas phase by the white-rot fungi Trametes versicolor, Pleurotus ostreatus, Bjerkandera adusta, and Phanerochaete chrysosporium was tested. Among the aromatic solvents, styrene was the compound that was most readily degraded, followed by ethylbenzene, xylenes, and toluene. Tetrahydrofuran and dichloromethane were also degraded, whereas dioxane could not be attacked by fungi under the conditions used. Acrylonitrile and aniline were degraded very well, whereas pyridine was resistant to degradation. The process for removing styrene is now in the scaling-up stage.

  19. Decay threshold of acetylated rattan (Calamus manan) against soft rot

    Institute of Scientific and Technical Information of China (English)

    Norul Hisham Hamid; Mike Hale

    2013-01-01

    We investigated the resistance of acetylated rattan against soft rot and other soil inhabiting micro-organisms in comparison with wood of beech and Scots pine.Calamus manan of 10 and 13 years old under rubber tree canopy was acetylated to different levels by reaction times (0.25 to 30 hours) and was tested for soft rot decay for 32 weeks.Acetylated rattan at decay protection thresholds of 15.4% and 16.2% weight gain (WG) were fully protected,as shown by both weight loss and strength loss criteria.The static bending properties of untreated rattan decayed by soft rot were significantly lower than for acetylated rattan.

  20. Screening of Sweet Potato Germplasm Resources Resistant to Rot Nematode and Evaluation of Their Disease Resistance%甘薯抗茎线虫病种质资源的筛选与抗病性评价

    Institute of Scientific and Technical Information of China (English)

    孙厚俊; 赵永强; 谢逸萍; 陈晓宇; 邢继英

    2011-01-01

    对81份甘薯材料进行了茎线虫病、黑斑病和根腐病抗性鉴定和评价.结果表明:同时抗这3种病害的甘薯品种(系)较少,仅郑04-4-2和徐062826时甘薯茎线虫病抗侵入和抗扩展的同时,对黑斑病和根腐病也具有较高的抗性水平;另外有部分品种(系)如泰中7号、浙紫1号、徐060407等达到抗两病水平,可作为甘薯抗病育种的双抗亲本加以利用.%In this study, the resistances of 81 sweet potato germplasm resources to sweet potato rot nematode, black rot and root rot were identified and evaluated. The results indicated that very few sweet potato varieties (lines) could simultaneously resist these three diseases, only Zheng 04-4 -2 and Xu 062826 had high resistances not only to the invasion and expansion of rot nematode, but also to black rot and root rot. In addition, some tested resources such as Taizhong No. 7, Zhezi No. 1 and Xu 060407 had the double resistances, and they can be used as the double - resistant parents in the disease - resistant breeding of sweet potato.

  1. Fungicide seed treatment and host resistance for the management of wheat crown rot caused by Fusarium culmorum

    Directory of Open Access Journals (Sweden)

    Shree R Pariyar

    2014-11-01

    Full Text Available Seed treatment of wheat with the fungicide thiabendazole on the development of crown rot caused by Fusarium culmorum was evaluated on six wheat genotypes with different genetic sources of resistance under controlled conditions in a growth chamber. Seed of three susceptible (S cultivars, Seri 82 (Spring bread wheat, Kiziltan 91 (Winter durum Wheat, and Demir 2000 (Winter bread wheat and three moderately resistant (MR wheat lines, 2-49 (Spring bread wheat, Altay 2000 (Winter bread wheat, and Burbot-6 (Winter bread wheat were treated with thiabendazole at concentrations of 25, 50 and 100 g ai per 100 kg seeds. Thiabendazole seed treatment caused a significant (P< 0.05 reduction in severity of crown rot on 4 out of the 6 wheat genotypes. The highest crown score reduction was recorded on S genotypes Seri 82 and Demir 2000. Thiabendazole at 100 g ai per 100 kg seed gave the highest CS reduction on both the S and MR wheat genotypes. Seed coating with thiabendazole did not show any effect on plant height, plant weight, root length and root weight. No phytotoxicity symptoms were observed at any concentration of the fungicide.

  2. Incidence of crown rot disease of wheat caused by Fusarium pseudograminearum as a new soil born fungal species in north west Iran.

    Science.gov (United States)

    Saremi, H; Ammarellou, A; Jafary, H

    2007-10-15

    Root rot and crown rot is one of the main important fungal diseases on wheat in North West Iran. The disease was studied during 1999-2004 growing seasons in four provinces including Qazvin, Zanjan, East Azarbyjan and Ardabil. Different wheat fields in the areas studied were visited and samples of the plants showing symptoms like chlorosis, withering, whiting of spikes, growth reduction and white heads were collected and transferred to the laboratory. Samples were surface sterilized with sodium hypochlorite and then cultured on common media (PDA) and specific media (PPA and CLA). Totally 155 fungal isolates belonging to five genera were identified and the pathogen most frequently isolated was Fusarium pseudograminearum (formerly known as F. graminearum Group 1). This species normally causes crown rot resulting in severe damage in several locations under dry spring conditions. The disease caused losses from 18-45.5% in the fields where the season and crop rotation allowed the disease to build up. Prolonged moisture stresses coupled with relatively high soil temperature in the fall enhanced early disease development on the roots and sub crown internodes. Environmental conditions and genetic susceptibility of cultivars were the two main factors affecting diseases incidence.

  3. BIOCHEMICAL PULPING OF REED PRETREATED BY WHITE ROT FUNGI

    Institute of Scientific and Technical Information of China (English)

    ShiyuFu; AniwarApiz; HuaiyuZhan

    2004-01-01

    The Soda-AQ pulps were made from reed pretreated by white rot fungi Panus conchatus. Cyathus stercoreus and Pleurotus florida respectively. It was found that kappa number decreased and the brightness increased for Soda-AQ pulps from the reed treated by Pleurotus florida and Panus conchatus, but it was reverse for the pulp from reed treated by Cyathus stercoreus. The result indicated that white rot fungi Pleurotus .florida and Panus conchatus were selective to degrade lignin inreed, which were good for biopulping, but Cyathus stercoreus was preferential to degrade cellulose, which was not good for biopulping.

  4. BIOCHEMICAL PULPING OF REED PRETREATED BY WHITE ROT FUNGI

    Institute of Scientific and Technical Information of China (English)

    Shiyu Fu; Aniwar Apiz; Huaiyu Zhan

    2004-01-01

    The Soda-AQ pulps were made from reed pretreated by white rot fungi Panus conchatus,Cyathus stercoreus and Pleurotus florida respectively. It was found that kappa number decreased and the brightness increased for Soda-AQ pulps from the reed treated by Pleurotus florida and Panus conchatus, but it was reverse for the pulp from reed treated by Cyathus stercoreus. The result indicated that white rot fungi Pleurotus florida and Panus conchatus were selective to degrade lignin in reed, which were good for biopulping, but Cyathus stercoreus was preferential to degrade cellulose,which was not good for biopulping.

  5. Repression of hla by rot Is Dependent on sae in Staphylococcus aureus▿

    OpenAIRE

    Li, Dongmei; Cheung, Ambrose

    2008-01-01

    The regulatory locus sae is a two-component system in Staphylococcus aureus that regulates many important virulence factors, including alpha-toxin (encoded by hla) at the transcriptional level. The SarA homologs Rot and SarT were previously shown to be repressors of hla in selected S. aureus backgrounds. To delineate the interaction of rot and sae and the contribution of sarT to hla expression, an assortment of rot and sae isogenic single mutants, a rot sae double mutant, and a rot sae sarT m...

  6. Geographic differentiation of Pseudomonas brassicacearum populations and bio-control of take-all disease of wheat and Pythium root rot of canola%Pseudomonas brassicacearum的数量分布差异及生物防治小麦全蚀病和油菜根腐病

    Institute of Scientific and Technical Information of China (English)

    P. R. HARVEY; R. A. WARREN; W. ACHOUAK; M. H. RYDER

    2005-01-01

    Strains representing populations of Pseudomonas brassicacearum from two contrasting South Australian wheat field soils were characterised by 3 PCR-based genotyping techniques and 3 phenotypic traits. Populations were highly diverse and significant levels of genotypic and bacterial-haplotype differentiation (GST and X2) were observed between the two geographical and two root-zone (i.e. rhizoplane and rhizosphere) populations(P<0.05).Three quarters of all strains had unique haplotypes and greater than 90% of these were specific to their population of origin. The average haplotype similarity among all strains was low (22%) and cluster analysis provided no evidence of relatedness on geographical origin or position in the root zone. These analyses indicate restrictions to inter-population gene flow and suggest that differentiation was due to random genetic drift and rhizoplane-based genotypic selection associated with the contrasting soils. One third of all strains tested positive for the 2,4-diacetylphloroglucinol biosynthesis gene(PhlD) and formed a related group (60% similarity).Four PhlD-positive strains(two wild types and their phenotypic variants) gave significant (P<0.05) bio-control of wheat take-all disease and Pythium damping-off of canola,indicating potential to control root disease complexes caused by these pathogens.%通过3种PCR技术测定基因特征和测定3种生化特征,对来自南澳洲两块对比小麦田土壤中的Pseudomonas brassicacearum种群的菌株进行了分析研究.结果显示,两种不同土壤和两种不同根部区域(根表和根际),该种群具有高度多样性,其基因型和基因组也具有显著差异(P<0.05).所分离到的菌株中,四分之三具有独特的基因组,90%以上的基因组是其原种群所独具有的.所有菌株的基因组的平均同源性比较低(22%),聚类分析不能证明来自不同小麦田和不同根部区域的菌株具有亲缘性.聚类分析显示,种群内的基因流动是受

  7. Root Infection and Systemic Colonization of Maize by Colletotrichum graminicola▿

    Science.gov (United States)

    Sukno, Serenella A.; García, Verónica M.; Shaw, Brian D.; Thon, Michael R.

    2008-01-01

    Colletotrichum graminicola is a filamentous ascomycete that causes anthracnose disease of maize. While the fungus can cause devastating foliar leaf blight and stalk rot diseases, little is known about its ability to infect roots. Previously published reports suggest that C. graminicola may infect maize roots and that root infections may contribute to the colonization of aboveground plant tissues, leading to disease. To determine whether C. graminicola can infect maize roots and whether root infections can result in the colonization of aboveground plant tissues, we developed a green fluorescent protein-tagged strain and used it to study the plant root colonization and infection process in vivo. We observed structures produced by other root pathogenic fungi, including runner hyphae, hyphopodia, and microsclerotia. A mosaic pattern of infection resulted from specific epidermal and cortical cells becoming infected by intercellular hyphae while surrounding cells were uninfected, a pattern that is distinctly different from that described for leaves. Interestingly, falcate conidia, normally restricted to acervuli, were also found filling epidermal cells and root hairs. Twenty-eight percent of plants challenged with soilborne inoculum became infected in aboveground plant parts (stem and/or leaves), indicating that root infection can lead to asymptomatic systemic colonization of the plants. Many of the traits observed for C. graminicola have been previously reported for other root-pathogenic fungi, suggesting that these traits are evolutionally conserved in multiple fungal lineages. These observations suggest that root infection may be an important component of the maize anthracnose disease cycle. PMID:18065625

  8. Root infection and systemic colonization of maize by Colletotrichum graminicola.

    Science.gov (United States)

    Sukno, Serenella A; García, Verónica M; Shaw, Brian D; Thon, Michael R

    2008-02-01

    Colletotrichum graminicola is a filamentous ascomycete that causes anthracnose disease of maize. While the fungus can cause devastating foliar leaf blight and stalk rot diseases, little is known about its ability to infect roots. Previously published reports suggest that C. graminicola may infect maize roots and that root infections may contribute to the colonization of aboveground plant tissues, leading to disease. To determine whether C. graminicola can infect maize roots and whether root infections can result in the colonization of aboveground plant tissues, we developed a green fluorescent protein-tagged strain and used it to study the plant root colonization and infection process in vivo. We observed structures produced by other root pathogenic fungi, including runner hyphae, hyphopodia, and microsclerotia. A mosaic pattern of infection resulted from specific epidermal and cortical cells becoming infected by intercellular hyphae while surrounding cells were uninfected, a pattern that is distinctly different from that described for leaves. Interestingly, falcate conidia, normally restricted to acervuli, were also found filling epidermal cells and root hairs. Twenty-eight percent of plants challenged with soilborne inoculum became infected in aboveground plant parts (stem and/or leaves), indicating that root infection can lead to asymptomatic systemic colonization of the plants. Many of the traits observed for C. graminicola have been previously reported for other root-pathogenic fungi, suggesting that these traits are evolutionally conserved in multiple fungal lineages. These observations suggest that root infection may be an important component of the maize anthracnose disease cycle.

  9. Trichoderma rot on ‘Fallglo’ Tangerine Fruit

    Science.gov (United States)

    In September 2009, brown rot symptoms were observed on ‘Fallglo’ fruit after 7 weeks of storage. Fourteen days prior to harvest, fruit were treated by dipping into one of four different fungicide solutions. Control fruit were dipped in tap water. After harvest, the fruit were degreened with 5 ppm et...

  10. Advancing our understanding of charcoal rot in soybeans

    Science.gov (United States)

    Charcoal rot (Macrophomina phaseolina (Tassi) Goid ) of soybean [Glycine max (L.) Merr.], is an important but commonly misidentified disease, and very few summary articles exist on this pathosystem. Research conducted over the last 10 years has improved our understanding of the environment conducive...

  11. Evaluation of common bean (Phaseolus vulgaris) response to charcoal rot

    Science.gov (United States)

    Charcoal rot in common beans (Phaseolus vulgaris L.), caused by Macrophomina phaseolina (Tassi) Gold. (Mph), is an endemic disease in the prevailing hot and dry conditions in southern Puerto Rico. This study evaluated the 120 bean genotypes that compose the BASE 120 panel under screenhouse conditio...

  12. Antibacterial activity of plant defensins against alfalfa crown rot pathogens

    Science.gov (United States)

    Alfalfa (Medicago sativa) is the fourth most widely grown crop in the United States. Alfalfa crown rot is a disease complex that severely decreases alfalfa stand density and productivity in all alfalfa-producing areas. Currently, there are no viable methods of disease control. Plant defensins are sm...

  13. Detecting cotton boll rot with an electronic nose

    Science.gov (United States)

    South Carolina Boll Rot is an emerging disease of cotton, Gossypium hirsutum L., caused by the opportunistic bacteria, Pantoea agglomerans (Ewing and Fife). Unlike typical fungal diseases, bolls infected with P. agglomerans continue to appear normal externally, complicating early and rapid detectio...

  14. Rice Sheath Rot: An Emerging Ubiquitous Destructive Disease Complex.

    Science.gov (United States)

    Bigirimana, Vincent de P; Hua, Gia K H; Nyamangyoku, Obedi I; Höfte, Monica

    2015-01-01

    Around one century ago, a rice disease characterized mainly by rotting of sheaths was reported in Taiwan. The causal agent was identified as Acrocylindrium oryzae, later known as Sarocladium oryzae. Since then it has become clear that various other organisms can cause similar disease symptoms, including Fusarium sp. and fluorescent pseudomonads. These organisms have in common that they produce a range of phytotoxins that induce necrosis in plants. The same agents also cause grain discoloration, chaffiness, and sterility and are all seed-transmitted. Rice sheath rot disease symptoms are found in all rice-growing areas of the world. The disease is now getting momentum and is considered as an important emerging rice production threat. The disease can lead to variable yield losses, which can be as high as 85%. This review aims at improving our understanding of the disease etiology of rice sheath rot and mainly deals with the three most reported rice sheath rot pathogens: S. oryzae, the Fusarium fujikuroi complex, and Pseudomonas fuscovaginae. Causal agents, pathogenicity determinants, interactions among the various pathogens, epidemiology, geographical distribution, and control options will be discussed.

  15. Reference rot in scholarly statement: threat and remedy

    Directory of Open Access Journals (Sweden)

    Peter Burnhill

    2015-07-01

    Full Text Available As the scholarly communication system evolves to become natively web based, citations now commonly include hyperlinks to content that is issued on the web. The content at the end of those hyperlinks is subject to what has been termed ‘reference rot’: a link may break or the content at the end of the link may no longer represent what was first noted as significant. Reference rot threatens both the usability of what is published and the long-term integrity of the scholarly record. The aim of the Hiberlink project has been to focus on this problem and then to compile and analyse a large corpus of full-text publications in order to quantify the extent of reference rot. The results are now out, and the task has shifted to alerting publishers and libraries on what to do in order to ensure that published web-based references do not rot over time. This has implications for the integrity of the scholarly record and for authors of that record. Fortunately, the Hiberlink project has progressed further than originally envisaged and has recommended remedies aimed at alleviating reference rot.

  16. Production and optimization of ligninolytic enzymes by white rot ...

    African Journals Online (AJOL)

    Production and optimization of ligninolytic enzymes by white rot fungus ... size and nutritional factors (carbon and nitrogen ratio, mediators and metal ions). ... manganese peroxidase (MnP), 2700 IU/ml for lignins peroxidase (LiP) and 345 IU/ml ...

  17. Use of sodium metasilicate for management of peach brown rot

    Directory of Open Access Journals (Sweden)

    Elizandra Pivotto Pavanello

    2016-09-01

    Full Text Available Peach brown rot, caused by the Monilinia fructicola fungus, is the main disease affecting peach crops, and it is mainly controlled via frequent fungicide applications. This study aimed at searching for alternatives to the intensive use of chemicals, evaluating silicon doses to control pre and postharvest peach brown rot and their influence on maturation parameters and fruit quality. Treatments consisted of control (water and sodium metasilicate doses (2 g L-1, 4 g L-1, 6 g L-1, 8 g L-1 and 10 g L-1 of water. The following assessments were made: spore germination and in vitro mycelial growth, brown rot incidence, soluble solids, titratable acidity, flesh firmness, total polyphenol content and fruit ethylene production and respiration rate. The 2 g L-1 dose reduced spore germination by 95 %. Doses of 6 g L-1 and 8 g L-1 satisfactorily reduced the disease incidence in the field, with 77 % and 89.2 % control, respectively. Sodium metasilicate resulted in the maintenance of great fruit firmness, reduced respiration and ethylene production and increased total polyphenol synthesis, but it did not influence the titratable acidity or soluble solids. Applying 6 g L-1 may potentially control pre and postharvest peach brown rot, besides increasing the total polyphenol synthesis and maintaining a higher flesh firmness.

  18. Fusarium stalk blight and rot in sugar beet

    Science.gov (United States)

    Fusarium stalk blight of sugar beet can cause reductions or complete loss of seed production. The causal agent is Fusarium oxysporum. In addition, Fusarium solani has been demonstrated to cause a rot of sugar beet seed stalk, and other species have been reported associated with sugar beet fruit, but...

  19. OXIDATION OF PERSISTANT ENVIRONMENTAL POLLUTANTS BY A WHITE ROT FUNGUS

    Science.gov (United States)

    The white rot fungus Phanerochaete chrysosporium degraded DDT [1,1,-bis(4-chlorophenyl)-2,2,2-trichloroethane], 3,4,3',4'-tetrachlorobiphenyl, 2,4,5,2',-4',5'-hexachlorobiphenyl, 2,3,7,8-tetrachlorodibenzo-p-dioxin, lindane (1,2,3,4,5,6-hexachlorocylohexane), and benzo[a]pyrene t...

  20. Botanicals to Control Soft Rot Bacteria of Potato

    Directory of Open Access Journals (Sweden)

    M. M. Rahman

    2012-01-01

    Full Text Available Extracts from eleven different plant species such as jute (Corchorus capsularis L., cheerota (Swertia chiraita Ham., chatim (Alstonia scholaris L., mander (Erythrina variegata, bael (Aegle marmelos L., marigold (Tagetes erecta, onion (Allium cepa, garlic (Allium sativum L., neem (Azadiracta indica, lime (Citrus aurantifolia, and turmeric (Curcuma longa L. were tested for antibacterial activity against potato soft rot bacteria, E. carotovora subsp. carotovora (Ecc P-138, under in vitro and storage conditions. Previously, Ecc P-138 was identified as the most aggressive soft rot bacterium in Bangladeshi potatoes. Of the 11 different plant extracts, only extracts from dried jute leaves and cheerota significantly inhibited growth of Ecc P-138 in vitro. Finally, both plant extracts were tested to control the soft rot disease of potato tuber under storage conditions. In a 22-week storage condition, the treated potatoes were significantly more protected against the soft rot infection than those of untreated samples in terms of infection rate and weight loss. The jute leaf extracts showed more pronounced inhibitory effects on Ecc-138 growth both in in vitro and storage experiments.

  1. Monosporascus cannonballus在海洋环境中的发现%The finding of Monosporascus cannonballus in marine environment

    Institute of Scientific and Technical Information of China (English)

    金静; 黄金光

    2009-01-01

    @@ Troutman & Matejka(1970)从美国亚利桑那州(Arizona)的香瓜Cucumis melo L.病株上分离到一种未鉴定真菌(unidentified fungus),该菌能造成香瓜侧根的腐败,病部散生多数黑色圆形小点.

  2. Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis) fruits in Vietnam

    Science.gov (United States)

    Schena, Leonardo; Jung, Thomas; Evoli, Maria; Pane, Antonella; Van Hoa, Nguyen; Van Tri, Mai; Wright, Sandra; Ramstedt, Mauritz; Olsson, Christer; Faedda, Roberto; Magnano di San Lio, Gaetano

    2017-01-01

    Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana) rootstocks grafted with ‘King’ mandarin (Citrus nobilis) and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch’s postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi), sweet orange (Citrus x sinensis) and bergamot (Citrus x bergamia) as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on ‘Carrizo’ citrange (C. sinensis ‘Washington Navel’ x Poncirus trifoliata). This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity. PMID:28208159

  3. Root resorption

    DEFF Research Database (Denmark)

    Kjaer, Inger

    2014-01-01

    Introduction: This paper summarizes the different conditions, which have a well-known influence on the resorption of tooth roots, exemplified by trauma and orthodontic treatment. The concept of the paper is to summarize and explain symptoms and signs of importance for avoiding resorption during...... orthodontic treatment. The Hypothesis: The hypothesis in this paper is that three different tissue layers covering the root in the so-called periroot sheet can explain signs and symptoms of importance for avoiding root resorption during orthodontic treatment. These different tissue layers are; outermost...... processes provoked by trauma and orthodontic pressure. Inflammatory reactions are followed by resorptive processes in the periroot sheet and along the root surface. Evaluation of the Hypothesis: Different morphologies in the dentition are signs of abnormal epithelium or an abnormal mesodermal layer. It has...

  4. Evaluation of Trichoderma isolates as potential biological control agent against soybean charcoal rot disease caused by Macrophomina phaseolina

    Directory of Open Access Journals (Sweden)

    Elham Khalili

    2016-05-01

    Full Text Available Macrophomina phaseolina (Tassi Goid remains the prevailing causal agent of charcoal rot disease that significantly suppresses the yield of a variety of oilseed crops. Its wide host range and ability to survive under arid conditions, coupled with the ineffective use of fungicides against it, have spurred scientific endeavours for alternative avenues to control this phytopathogen. Hence, the present study aimed to provide empirical evidence of the efficacy of three fungal isolates (T2, T10 and T12 of Trichoderma harzianum as biological control agents against charcoal rot in soybean (Glycine max L.. The results of the in vitro studies revealed that all three fungal isolates significantly inhibited the growth of M. phaseolina phytopathogen, with T12 showing considerably higher inhibition effect than T2 and T10 isolates. T12 inhibited the growth of M. phaseolina in the dual culture (72.31% and volatile production (63.36% assays, and the hyperparasitism test indicated cell lysis following the interactions with T12 mycelia. T12 isolate was mostly effective in field experiments, observable in the attained minimum plant disease indices both in the soil incorporation (11.98% and seed inoculation (5.55% treatments, in comparison to isolates T2 and T10. Moreover, the stem and root lengths, as well as the seed weight, were considerably increased, as compared to the control. Hence, the findings reported in the present study supported the applicability of T12 isolate as possible alternative to fungicides for the control of charcoal rot in soybean.

  5. Application of scan line filling to leaf image segmentation of sugarcane red rot disease

    Science.gov (United States)

    Zhao, Jinhui; Liu, Muhua; Yao, Mingyin

    2009-07-01

    Red rot disease is a common disease at the seedling stage of sugarcane. In order to identify red rot disease effectively, a segmentation algorithm for leaf images of sugarcane red rot disease using scan line filling is proposed. The proposed algorithm has six stages. During the first stage, the class of green plants is separated from the class of non-green plants using the color feature of 2G-R-B. At the second stage, connected regions of the class of green plants are labeled. At the third stage, outer contours are extracted. At the fourth stage, the regions surrounded by outer contours are filled using scan line filling. At the fifth stage, the images are colorized. At the sixth stage, red rot diseased spots are extracted using the color feature. The experimental results show that this algorithm can extract red rot diseased spots effectively, and the accurate rate of image segmentation for red rot diseases is 96%.

  6. Pengaruh Penambahan Jamur Pelapuk Putih (White Rot Fungi pada Proses Pengomposan Tandan Kosong Kelapa Sawit

    Directory of Open Access Journals (Sweden)

    Nasrul Nasrul

    2010-12-01

    Full Text Available Composting is nowadays a general treatment method for agriculture waste such as empty fruit bunch. This research article reported the composting process of the empty fruit bunches. The effect of addition of white rot fungi (Phanerochaete Chrysosporium as an activator on composting product was studied. Experiment results indicated that white rot fungi is a good activator to improve degradation process of the empty fruit bunch become an organic fertilizer. White rot fungi has capable to increase composting period become shorter in compare with original composting without addition of white rot fungi. The organic fertilizer product as regulation issued by the Standar Nasional Indonesia (NSI can be achieved in duration of 3 months, while for original process without addition of white rot fungi longer degradation time is necessary. Keyword: Composting, empty fruit bunch, white rot fungi

  7. Fusarium rot of onion and possible use of bioproduct

    Directory of Open Access Journals (Sweden)

    Klokočar-Šmit Zlata

    2008-01-01

    Full Text Available Several species of Fusarium are causal agents of onion rot in field and storage. Most prevalent are F. oxysporum f. sp. cepae and F. solani, and recently F. proliferatum, a toxigenic species. Most frequently isolated fungi in our field experiments were F. solani and F. proliferatum with different pathogenicity. Certain differences in antagonistic activity of Trichoderma asperellum on different isolates of F. proliferatum and F. solani have been found in in vitro study in dual culture, expressed as a slower inhibition of growth of the former, and faster of the latter pathogen. Antagonistic abilities of species from genus Trichoderma (T. asperellum are important, and have already been exploited in formulated biocontrol products in organic and conventional production, in order to prevent soil borne pathogens inducing fusarium wilt and rot. The importance of preventing onion infection by Fusarium spp., possible mycotoxin producers, has been underlined.

  8. Cellulose Degradation by Cellulose-Clearing and Non-Cellulose-Clearing Brown-Rot Fungi

    OpenAIRE

    Highley, Terry L.

    1980-01-01

    Cellulose degradation by four cellulose-clearing brown-rot fungi in the Coniophoraceae—Coniophora prasinoides, C. puteana, Leucogyrophana arizonica, and L. olivascens—is compared with that of a non-cellulose-clearing brown-rot fungus, Poria placenta. The cellulose- and the non-cellulose-clearing brown-rot fungi apparently employ similar mechanisms to depolymerize cellulose; most likely a nonenzymatic mechanism is involved.

  9. Environmental Factors and Bioremediation of Xenobiotics Using White Rot Fungi

    OpenAIRE

    Magan, Naresh; Fragoeiro, Silvia; Bastos, Catarina

    2010-01-01

    This review provides background information on the importance of bioremediation approaches. It describes the roles of fungi, specifically white rot fungi, and their extracellular enzymes, laccases, ligninases, and peroxidises, in the degradation of xenobiotic compounds such as single and mixtures of pesticides. We discuss the importance of abiotic factors such as water potential, temperature, and pH stress when considering an environmental screening approach, and examples are provided of the ...

  10. Rice Sheath Rot: An Emerging Ubiquitous Destructive Disease Complex

    OpenAIRE

    Vincent de Paul Bigirimana; Khuong Hoang Gia Hua; Obedi Ishibwela Nyamangyoku; Monica eHöfte

    2015-01-01

    Around one century ago, a rice disease characterized mainly by rotting of sheaths was reported in Taiwan. The causal agent was identified as Acrocylindrium oryzae, later known as Sarocladium oryzae. Since then it has become clear that various other organisms can cause similar disease symptoms, including Fusarium spp. and fluorescent pseudomonads. These organisms have in common that they produce a range of phytotoxins that induce necrosis in plants. The same agents also cause grain discolorati...

  11. Solubilization and Mineralization of Lignin by White Rot Fungi

    OpenAIRE

    Boyle, C. David; Bradley R. Kropp; Reid, Ian D.

    1992-01-01

    The white rot fungi Lentinula edodes, Phanerochaete chrysosporium, Pleurotus sajor-caju, Flammulina velutipes, and Schizophyllum commune were grown in liquid media containing 14C-lignin-labelled wood, and the formation of water-soluble 14C-labelled products and 14CO2, the growth of the fungi, and the activities of extracellular lignin peroxidase, manganese peroxidase, and laccase were measured. Conditions that affect the rate of lignin degradation were imposed, and both long-term (0- to 16-da...

  12. Occurrence of Sclerotium Rot of Cucumber Caused by Sclerotium rolfsii

    Directory of Open Access Journals (Sweden)

    Jin-Hyeuk Kwon

    2015-06-01

    Full Text Available Sclerotium rot of cucumber (Cucumis sativus L. occurred at the experimental field of Gyeongsangnam-do Agricultural Research and Extension Services in July 2012. The typical symptoms included wilt, rot, and water-soaking on stems and fruits and severely infected plants eventually died. White mycelial mats spread over lesions, and then sclerotia were formed on fruit and near soil line. The sclerotia were globoid in shape, white to brown in color and 1−3 mm in size and the hyphal width was 4−8 μm. The optimum temperature for mycelial growth and sclerotia formation on PDA was 30oC. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. For further identification, the complete internal transcribed spacer (ITS rDNA region was amplified and sequenced. On the basis of mycological characteristics, ITS rDNA region comparison, and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report of sclerotium rot on cucumber caused by S. rolfsii in Korea.

  13. The First Report of Postharvest Stem Rot of Kohlrabi Caused by Sclerotinia sclerotiorum in Korea.

    Science.gov (United States)

    Kim, Joon-Young; Aktaruzzaman, Md; Afroz, Tania; Hahm, Young-Il; Kim, Byung-Sup

    2014-12-01

    In March 2014, a kohlrabi stem rot sample was collected from the cold storage room of Daegwallyong Horticultural Cooperative, Korea. White and fuzzy mycelial growth was observed on the stem, symptomatic of stem rot disease. The pathogen was isolated from the infected stem and cultured on potato dextrose agar for further fungal morphological observation and to confirm its pathogenicity, according to Koch's postulates. Morphological data, pathogenicity test results, and rDNA sequences of internal transcribed spacer regions (ITS 1 and 4) showed that the postharvest stem rot of kohlrabi was caused by Sclerotinia sclerotiorum. This is the first report of postharvest stem rot of kohlrabi in Korea.

  14. Role of Bradyrhizobium japonicum and Trichoderma spp. in the control of root rot disease of soybean

    Directory of Open Access Journals (Sweden)

    Syed Ehteshamul-Haque

    2014-08-01

    Full Text Available Seed treatment of soybean with Bndyrhizobium japonicum, Trichoderma harzianum, T. viride, T. hamatum, T. koningii and T. pseudokoningii significantly controlled the infection of 30-day-old seedlingsby Maerophomina phaseolina, Rhizoctonia solani and Fusarium spp. In 60-day-old plants Trichoderma spp.. and B. japonicum inhibited the grouth of R. solani and Fusarium spp., whereas the use of B. japonicum (TAL-102 with T. harzianum. T. viride, T. koningii and T. pseudokoningii controlled the infection by M. phaseolina. Greater grain yield was recorded when B. japonium (TAI-102 was used with T. hamatum.

  15. The potential of biological soil disinfestation to manage Fusarium foot and root rot in Asparagus

    NARCIS (Netherlands)

    Blok, W.J.; Coenen, G.C.M.; Lamers, J.G.; Termorshuizen, A.J.

    2008-01-01

    In a field experiment on an abandoned asparagus field we studied the effect of Biological Soil Disinfestation (BSD) on survival of buried inoculum samples of three test pathogens (Fusarium redolens f.sp. asparagi (FRA), Rhizoctonia tuliparum (RT) and Verticillium dahliae (VD)) and on the Fusarium in

  16. Managing foliar and root rot diseases of alfalfa for improving yield and persistance

    Science.gov (United States)

    Resistance to the six most common diseases across the United States is available in modern alfalfa cultivars. However, several diseases are becoming increasing problems in many parts of the country. Recognizing these problems is the first step in using crop management strategies to minimize diseases...

  17. Using Leaf Temperature to Detect Pythium Root Rot Stress in Geranium

    Science.gov (United States)

    Diagnosis of incipient disease based on visual symptoms of geraniums (Pelargonium × hortorum L. H. Bailey) exposed to water mold pathogens is often difficult, especially when the plants are maintained under optimum growing conditions. Such plants tend to be asymptomatic until late in the infection ...

  18. Antifungal effect of some plant extracts against factors wheat root rot

    Science.gov (United States)

    Atmaca, Sevim; Şimşek, Şeyda; Denek, Yunus Emre

    2017-04-01

    Methanol leaf extracts of Humulus lupulus L. and Achillea millefolium L. were evaluated for antifungal activity against economically important phytopathogenic fungi including Fusarium culmorum (W. G. Smith) Sacc. The final concentrations of the methanol extracts obtained from the plants were added to the Potato Dextrose Agar (PDA) at 1%, 2%, 4% and 8% doses. Mycelial disks of pathogens (6 mm in diameter) removed from the margins of a 7 days old culture were transferred to PDA media containing the plant extracts at tested concentrations. Four replicates were used per treatment. For each plant extract and concentration, inhibition of radial growth compared with the untreated control was calculated after 7 days of incubation at 24±1°C, in the dark. Extracts H. lupulus and A. millefolium inhibited the mycelial growth of F. culmorum of mycelial growth of 8% dose of the pathogens by 92.77% and 69.83%, respectively. It has been observed that the antifungal effect of the extracts increases with dose increase. As a result, at least micelle growth and the highest percent inhibition rate were obtained at 8% dose of the extract H. lupulus. H. lupulus extract can be used as a biological preparation.

  19. The potential of biological soil disinfestation to manage Fusarium foot and root rot in Asparagus

    NARCIS (Netherlands)

    Blok, W.J.; Coenen, G.C.M.; Lamers, J.G.; Termorshuizen, A.J.

    2008-01-01

    In a field experiment on an abandoned asparagus field we studied the effect of Biological Soil Disinfestation (BSD) on survival of buried inoculum samples of three test pathogens (Fusarium redolens f.sp. asparagi (FRA), Rhizoctonia tuliparum (RT) and Verticillium dahliae (VD)) and on the Fusarium

  20. Genetic differentiation of charcoal rot pathogen, Macrophomina phaseolina, into specific groups using URP-PCR.

    Science.gov (United States)

    Jana, T K; Singh, N K; Koundal, K R; Sharma, T R

    2005-02-01

    Forty isolates of Macrophomina phaseolina, a pathogen causing charcoal dry root rot of soybean, cotton, and chickpea, were genetically characterized with universal rice primers (URP; primers derived from DNA repeat sequences in the rice genome) using polymerase chain reaction (URP-PCR). Out of 12 URPs used in this study, 5 primers were effective in producing polymorphic fingerprint patterns from the DNA of M. phaseolina isolates. Three primers (URP-2F, URP-6R, and URP-30F) were quite informative and produced high levels of polymorphism among the isolates of M. phaseolina. Analysis of the entire fingerprint profiles using unweighted pair-group method with arithmetic averages (UPGMA) clearly differentiated M. phaseolina isolates obtained from soybean, cotton, and chickpea hosts into specific groups. In this study, we found for the first time transferability and use of PCR primers derived from plant genomes to generate host-specific fingerprint profiles of M. phaseolina, a broad host range plant pathogenic fungus. These results demonstrate that URPs are sensitive and technically simple to use for assaying genetic variability in M. phaseolina populations.

  1. Carbon Dioxide and Methane Formation in Norway Spruce Stems Infected by White-Rot Fungi

    Directory of Open Access Journals (Sweden)

    Ari M. Hietala

    2015-09-01

    Full Text Available Globally, billions of tons of carbon sequestered in trees are annually recycled back to the atmosphere through wood decomposition by microbes. In Norway, every fifth Norway spruce shows at final harvest infection by pathogenic white-rot fungi in the genera Heterobasidion and Armillaria. As these fungi can mineralize all components of wood, we predicted that they have a significant carbon footprint. Gas samples taken from infected stems were analyzed for CO2 and CH4 concentrations, and wood samples from different parts of the decay columns were incubated under hypoxic (4% O2 and anoxic laboratory conditions. In spring and summer the stem concentrations of CO2 were generally two times higher in trees with heartwood decay than in healthy trees. For most of the healthy trees and trees with heartwood decay, mean stem concentrations of CH4 were comparable to ambient air, and only some Armillaria infected trees showed moderately elevated CH4. Consistently, low CH4 production potentials were recorded in the laboratory experiment. Up-scaling of CO2 efflux due to wood decay in living trees suggests that the balance between carbon sequestration and emission may be substantially influenced in stands with high frequency of advanced root and stem heartwood decay.

  2. Effect of Trichoderma harzianum on maize rhizosphere microbiome and biocontrol of Fusarium Stalk rot.

    Science.gov (United States)

    Saravanakumar, Kandasamy; Li, Yaqian; Yu, Chuanjin; Wang, Qiang-Qiang; Wang, Meng; Sun, Jianan; Gao, Jin-Xin; Chen, Jie

    2017-05-11

    Fusarium stalk rot (FSR) caused by Fusarium graminearum (FG) significantly affects the productivity of maize grain crops. Application of agrochemicals to control the disease is harmful to environment. In this regard, use of biocontrol agent (BCA) is an alternative to agrochemicals. Although Trichoderma species are known as BCA, the selection of host-pathogen specific Trichoderma is essential for the successful field application. Hence, we screened a total of 100 Trichoderma isolates against FG, selected Trichoderma harzianum (CCTCC-RW0024) for greenhouse experiments and studied its effect on changes of maize rhizosphere microbiome and biocontrol of FSR. The strain CCTCC-RW0024 displayed high antagonistic activity (96.30%), disease reduction (86.66%), biocontrol-related enzyme and gene expression. The root colonization of the strain was confirmed by eGFP tagging and qRT-PCR analysis. Pyrosequencing revealed that exogenous inoculation of the strain in maize rhizosphere increased the plant growth promoting acidobacteria (18.4%), decreased 66% of FG, and also increased the plant growth. In addition, metabolites of this strain could interact with pathogenicity related transcriptional cofactor FgSWi6, thereby contributing to its inhibition. It is concluded that T. harzianum strain CCTCC-RW0024 is a potential BCA against FSR.

  3. Potassium and Phosphorus effects on disease severity of charcoal rot of soybean

    Science.gov (United States)

    The effects of potassium (K) and phosphorus (P) fertilizers on charcoal rot of soybean [Glycine max (L.) Merr.] are unknown. Therefore, the severity of charcoal rot was studied at five levels of K (0, 37, 75, 111 and 149 kg K ha-1) and a level that was equal to the recommended fertilizer applicatio...

  4. First Report of Calonectria hongkongensis Causing Fruit Rot of Rambutan (Nephelium lappaceum)

    NARCIS (Netherlands)

    Serrato-Diaz, L.M.; Latoni-Brailowsky, E.I.; Rivera-Vargas, L.I.; Goenaga, R.J.; Crous, P.W.; French-Monar, R.D.

    2013-01-01

    Fruit rot of rambutan is a pre- and post-harvest disease problem of rambutan orchards. In 2011, fruit rot was observed at USDA-ARS orchards in Mayaguez, Puerto Rico. Infected fruit were collected and 1 mm2 tissue sections were surface disinfested with 70% ethanol followed by 0.5% sodium hypochlorite

  5. Leaf Spot and Stem Rot on Wilford Swallowwort Caused by Stemphylium lycopersici in Korea.

    Science.gov (United States)

    Hong, Sung Kee; Choi, Hyo Won; Lee, Young Kee; Shim, Hong Sik; Lee, Sang Yeob

    2012-12-01

    In June 2012, leaf spot and stem rot were observed on Wilford Swallowwort plants grown in Cheonan, Korea. Three fungal isolates obtained from the diseased leaves and stems were identified as Stemphylium lycopersici, based on morphological, cultural, and molecular characteristics and pathogenicity. This is the first report of leaf spot and stem rot on Wilford Swallowwort caused by S. lycopersici.

  6. Characterizing butt-rot fungi on USA-affiliated islands in the western Pacific

    Science.gov (United States)

    Phil Cannon; Ned B. Klopfenstein; Robert L. Schlub; Mee-Sook Kim; Yuko Ota; Norio Sahashi; Roland J. Quitugua; John W. Hanna; Amy L. Ross-Davis; J. D. Sweeney

    2014-01-01

    Ganoderma and Phellinus are genera that commonly cause tree butt-rot on USA-affiliated islands of the western Pacific. These fungal genera can be quite prevalent, especially in older mangrove stands. Although the majority of infections caused by these fungi lead to severe rotting of the heartwood, they typically do not directly kill the living tissues of the sapwood,...

  7. Enzymatic oxalic acid regulation correlated with wood degradation in four brown-rot fungi

    Science.gov (United States)

    Anne Christine Steenkjær Hastrup; Frederick Green III; Patricia K. Lebow; Bo Jensen

    2012-01-01

    Oxalic acid is a key component in the initiation of brown-rot decay and it has been suggested that it plays multiple roles during the degradation process. Oxalic acid is accumulated to varying degrees among brown-rot fungi; however, details on active regulation are scarce. The accumulation of oxalic acid was measured in this study from wood degraded by the four brown-...

  8. Control of speck rot in apple fruit caused by Phacidiopycnis washingtonensis with pre- and postharvest fungicides

    Science.gov (United States)

    Speck rot caused by Phacidiopycnis washingtonensis is a recently reported postharvest fruit rot disease of apple. Infection of apple fruit by the fungus occurs in the orchard, but symptoms develop during storage. In this study, selected pre- and postharvest fungicides were evaluated for control of s...

  9. First report of Fusarium hostae causing crown rot of wheat (Triticum spp.) in Turkey

    Science.gov (United States)

    Crown rot disease of wheat is caused by a complex of Fusarium species. To identify species associated with crown rot in Turkey, crowns and stems of bread wheat (Triticum aestivum L.) and durum wheat (T. durum Desf.) were collected from the Central and Southeast Anatolia, Black Sea, Aegean, Mediterr...

  10. Studies on the epidemiology of spear rot in oil palm (Elaeis guineensis Jacq.) in Suriname.

    NARCIS (Netherlands)

    Lande, van de H.L.

    1993-01-01

    The epidemiology of spear rot, an infectious disease of unknown etiology, was studied over 10 years at three government-owned oil palm plantations in Suriname. As with other and similar diseases, amarelecimento fatal in Brazil and pudrición del cogollo in Latin America, which too show rot and yellow

  11. Preharvest applications of fungicides for control of Sphaeropsis rot in stored apples

    Science.gov (United States)

    Sphaeropsis rot caused by Sphaeropsis pyriputrescens is a recently reported postharvest fruit rot disease of apple in Washington State and causes significant economic losses. Infection of apple fruit by the fungus occurs in the orchard, but decay symptoms develop during storage or in the market. The...

  12. Vine kill interval and temperature effects on Fusarium dry rot development in Russet Burbank

    Science.gov (United States)

    Fusarium dry rot disease development in potato storage is universal to all market sectors and regions. The objective of this 2-year study was to evaluate three possible management decisions that may impact Fusarium dry rot development in storage: a) vine kill to harvest time, b) harvested tuber pulp...

  13. Optimization of manganese peroxidase production by the white rot fungus Bjerkandera sp. strain BOS55.

    NARCIS (Netherlands)

    Mester, T.; Field, J.A.

    1997-01-01

    Manganese dependent peroxidase (MnP) is the most ubiquitous peroxidase produced by white rot fungi. MnP is known to be involved in lignin degradation, biobleaching and in the oxidation of hazardous organopollutants. Bjerkandera sp. strain BOS55 is a nitrogen-unregulated white rot fungus which produc

  14. Optimization of manganese peroxidase production by the white rot fungus Bjerkandera sp. strain BOS55.

    NARCIS (Netherlands)

    Mester, T.; Field, J.A.

    1997-01-01

    Manganese dependent peroxidase (MnP) is the most ubiquitous peroxidase produced by white rot fungi. MnP is known to be involved in lignin degradation, biobleaching and in the oxidation of hazardous organopollutants. Bjerkandera sp. strain BOS55 is a nitrogen-unregulated white rot fungus which

  15. Development of dry gram-negative bacteria biocontrol products and small pilot tests against dry rot

    Science.gov (United States)

    Pseudomonas fluorescens strains S11:P:12, P22:Y:05, and S22:T:04 suppress four important storage potato maladies; dry rot, late blight, pink rot, and sprouting. Studies were designed to identify methods for producing a dried, efficacious biological control product. The strains were evaluated individ...

  16. BIO-DEINKING OF ONP AND ITS EFFLUENT TREATMENT BY WHITE ROT FUNGUS

    Institute of Scientific and Technical Information of China (English)

    Lu Lin; Chunsheng Pang; Deqing Zhao; Liping Jiang

    2004-01-01

    Deinking of secondary fiber of ONP and effluent treatment with white rot fungus were studied in this paper. Results showed that white rot fungus exerted significant effect on deinking of ONP and CODcr decrease and degradation of pollutants of deinking effluent.

  17. The presence and survival of soft rot (Erwinia) in flower bulb production systems

    NARCIS (Netherlands)

    Doorn, van J.; Vreeburg, P.J.M.; Leeuwen, van P.J.; Dees, R.H.L.

    2011-01-01

    Soft rot is causing increasing damage in the flower bulb industry. Bulbous ornamentals such as Hyacinthus, Dahlia, Iris, Muscari, Freesia and Zantedeschia can be infected. Soft rot in flower bulbs is mainly caused by Dickeya spp. (Dickeya spp.) and Erwinia carotovora subsp. carotovora (Pectobacteriu

  18. First Report of Calonectria hongkongensis Causing Fruit Rot of Rambutan (Nephelium lappaceum)

    NARCIS (Netherlands)

    Serrato-Diaz, L.M.; Latoni-Brailowsky, E.I.; Rivera-Vargas, L.I.; Goenaga, R.J.; Crous, P.W.; French-Monar, R.D.

    2013-01-01

    Fruit rot of rambutan is a pre- and post-harvest disease problem of rambutan orchards. In 2011, fruit rot was observed at USDA-ARS orchards in Mayaguez, Puerto Rico. Infected fruit were collected and 1 mm2 tissue sections were surface disinfested with 70% ethanol followed by 0.5% sodium hypochlorite

  19. Studies on the epidemiology of spear rot in oil palm (Elaeis guineensis Jacq.) in Suriname

    NARCIS (Netherlands)

    Lande, van de H.L.

    1993-01-01

    The epidemiology of spear rot, an infectious disease of unknown etiology, was studied over 10 years at three government-owned oil palm plantations in Suriname. As with other and similar diseases, amarelecimento fatal in Brazil and pudrición del cogollo in Latin America, which too show rot

  20. Infection of apple fruit by Sphaeropsis pyriputrescens in the orchard in relation to Sphaeropsis rot in storage

    Science.gov (United States)

    Sphaeropsis rot, caused by Sphaeropsis pyriputrescens, is a recently recognized postharvest fruit rot disease of apple in the United States. The objectives of this study were to determine the timing of apple fruit infection in the orchard in relation to development of Sphaeropsis rot in storage and ...

  1. Are white-rot fungi a real biotechnological option for the improvement of environmental health?

    Science.gov (United States)

    Tortella, G; Durán, N; Rubilar, O; Parada, M; Diez, M C

    2015-06-01

    The use of white-rot fungi as a biotechnological tool for cleaning the environment of recalcitrant pollutants has been under evaluation for several years. However, it is still not possible to find sufficiently detailed investigations of this subject to conclude that these fungi can decontaminate the environment. In the present review, we have summarized and discussed evidence about the potential of white-rot fungi to degrade such pollutants as polycyclic aromatic hydrocarbons, dyes or antibiotics as an example of the complex structures that these microorganisms can attack. This review also discusses field experiment results and limitations of white-rot fungi trials from contaminated sites. Moreover, the use of catabolic potential of white-rot fungi in biopurification systems (biobeds) is also discussed. The current status and future perspectives of white-rot fungi, as a viable biotechnological alternative for improvement of environmental health are noted.

  2. Positive Root Bounds and Root Separation Bounds

    Science.gov (United States)

    Herman, Aaron Paul

    In this thesis, we study two classes of bounds on the roots of a polynomial (or polynomial system). A positive root bound of a polynomial is an upper bound on the largest positive root. A root separation bound of a polynomial is a lower bound on the distance between the roots. Both classes of bounds are fundamental tools in computer algebra and computational real algebraic geometry, with numerous applications. In the first part of the thesis, we study the quality of positive root bounds. Higher quality means that the relative over-estimation (the ratio of the bound and the largest positive root) is smaller. We find that all known positive root bounds can be arbitrarily bad. We then show that a particular positive root bound is tight for certain important classes of polynomials. In the remainder of the thesis, we turn to root separation bounds. We observe that known root separation bounds are usually very pessimistic. To our surprise, we also find that known root separation bounds are not compatible with the geometry of the roots (unlike positive root bounds). This motivates us to derive new root separation bounds. In the second part of this thesis, we derive a new root separation for univariate polynomials by transforming a known bound into a new improved bound. In the third part of this thesis, we use a similar strategy to derive a new improved root separation bound for polynomial systems.

  3. Suppression of maize root diseases caused by Macrophomina phaseolina, Fusarium moniliforme and Fusarium graminearum by plant growth promoting rhizobacteria.

    Science.gov (United States)

    Pal, K K; Tilak, K V; Saxena, A K; Dey, R; Singh, C S

    2001-01-01

    A plant growth-promoting isolate of a fluorescent Pseudomonas sp. EM85 and two bacilli isolates MR-11(2) and MRF, isolated from maize rhizosphere, were found strongly antagonistic to Fusarium moniliforme, Fusarium graminearum and Macrophomina phaseolina, causal agents of foot rots and wilting, collar rots/stalk rots and root rots and wilting, and charcoal rots of maize, respectively. Pseudomonas sp. EM85 produced antifungal antibiotics (Afa+), siderophore (Sid+), HCN (HCN+) and fluorescent pigments (Flu+) besides exhibiting plant growth promoting traits like nitrogen fixation, phosphate solubilization, and production of organic acids and IAA. While MR-11(2) produced siderophore (Sid+), antibiotics (Afa+) and antifungal volatiles (Afv+), MRF exhibited the production of antifungal antibiotics (Afa+) and siderophores (Sid+). Bacillus spp. MRF was also found to produce organic acids and IAA, solubilized tri-calcium phosphate and fixed nitrogen from the atmosphere. All three isolates suppressed the diseases caused by Fusarium moniliforme, Fusarium graminearum and Macrophomina phaseolina in vitro. A Tn5:: lacZ induced isogenic mutant of the fluorescent Pseudomonas EM85, M23, along with the two bacilli were evaluated for in situ disease suppression of maize. Results indicated that combined application of the two bacilli significantly (P = 0.05) reduced the Macrophomina-induced charcoal rots of maize by 56.04%. Treatments with the MRF isolate of Bacillus spp. and Tn5:: lacZ mutant (M23) of fluorescent Pseudomonas sp. EM85 significantly reduced collar rots, root and foot rots, and wilting of maize caused by Fusarium moniliforme and F. graminearum (P = 0.05) compared to all other treatments. All these isolates were found very efficient in colonizing the rhizotic zones of maize after inoculation. Evaluation of the population dynamics of the fluorescent Pseudomonas sp. EM85 using the Tn5:: lacZ marker and of the Bacillus spp. MRF and MR-11(2) using an antibiotic resistance

  4. Bacteriophages of Soft Rot Enterobacteriaceae-a minireview.

    Science.gov (United States)

    Czajkowski, Robert

    2016-01-01

    Soft rot Enterobacteriaceae (Pectobacterium spp. and Dickeya spp., formerly pectinolytic Erwinia spp.) are ubiquitous necrotrophic bacterial pathogens that infect a large number of different plant species worldwide, including economically important crops. Despite the fact that these bacteria have been studied for more than 50 years, little is known of their corresponding predators: bacteriophages, both lytic and lysogenic. The aim of this minireview is to critically summarize recent ecological, biological and molecular research on bacteriophages infecting Pectobacterium spp. and Dickeya spp. with the main focus on current and future perspectives in that field.

  5. Microsatellites from the charcoal rot fungus (Macrophomina phaseolina).

    Science.gov (United States)

    Baird, Richard E; Wadl, Phillip A; Wang, Xinwang; Johnson, Denita H; Rinehart, Timothy A; Abbas, Hamed K; Shier, Thomas; Trigiano, Robert N

    2009-05-01

    Microsatellite loci were identified from the charcoal rot fungus (Macrophomina phaseolina). Primer pairs for 46 loci were developed, and of these, 13 were optimized and screened using genomic DNA from 55 fungal isolates collected predominantly from two soybean fields in Mississippi. Twelve of the optimized loci were polymorphic and the number of alleles per locus ranged from 6 to 22. These microsatellites will be useful in population and pathogenicity studies to correspond with development of potential disease-resistant soybean and other susceptible crops. © 2009 Blackwell Publishing Ltd. No claim to original US government works.

  6. Enzyme activity in banana fruits rotted by Botryodiplodia theobromae Pat.

    Directory of Open Access Journals (Sweden)

    Nityananda Chakraborty

    2015-06-01

    Full Text Available Peroxidase and polyphenol oxidase activities in fruits of two cultivars of banana, 'champa' and 'kanthali' rotted by Botryodiplodia theobromae Pat. was studied. The enzymes showed much higher activities in infected than that in uninfected 'tissues. Increase in peroxidase activity was evidently inhibited by cycloheximide. Polyphenol oxidase activity was also inhibited in presence of phenylthiourea and Na-diethyldithiocarbamate more strongly by the former. Increase in activities seemed to be due to increased sytheses of the enzymes. In an in vitro culture, the fungus exhibited some peroxidase but no polyphenoloxidase activity.

  7. The emerging contribution of social wasps to grape rot disease ecology

    Directory of Open Access Journals (Sweden)

    Anne A. Madden

    2017-04-01

    Full Text Available Grape sour (bunch rot is a polymicrobial disease of vineyards that causes millions of dollars in lost revenue per year due to decreased quality of grapes and resultant wine. The disease is associated with damaged berries infected with a community of acetic acid bacteria, yeasts, and filamentous fungi that results in rotting berries with high amounts of undesirable volatile acidity. Many insect species cause the initial grape berry damage that can lead to this disease, but most studies have focused on the role of fruit flies in facilitating symptoms and vectoring the microorganisms of this disease complex. Like fruit flies, social wasps are abundant in vineyards where they feed on ripe berries and cause significant damage, while also dispersing yeasts involved in wine fermentation. Despite this, their possible role in disease facilitation and dispersal of grape rots has not been explored. We tested the hypothesis that the paper wasp Polistes dominulus could facilitate grape sour rot in the absence of other insect vectors. Using marker gene sequencing we characterized the bacterial and fungal community of wild-caught adults. We used a sterilized foraging arena to determine if these wasps transfer viable microorganisms when foraging. We then tested if wasps harboring their native microbial community, or those inoculated with sour rot, had an effect on grape sour rot incidence and severity using a laboratory foraging arena. We found that all wasps harbor some portion of the sour rot microbial community and that they have the ability to transfer viable microorganisms when foraging. Foraging by inoculated and uninoculated wasps led to an increase in berry rot disease symptom severity and incidence. Our results indicate that paper wasps can facilitate sour rot diseases in the absence of other vectors and that the mechanism of this facilitation may include both increasing host susceptibility and transmitting these microbial communities to the grapes

  8. The emerging contribution of social wasps to grape rot disease ecology.

    Science.gov (United States)

    Madden, Anne A; Boyden, Sean D; Soriano, Jonathan-Andrew N; Corey, Tyler B; Leff, Jonathan W; Fierer, Noah; Starks, Philip T

    2017-01-01

    Grape sour (bunch) rot is a polymicrobial disease of vineyards that causes millions of dollars in lost revenue per year due to decreased quality of grapes and resultant wine. The disease is associated with damaged berries infected with a community of acetic acid bacteria, yeasts, and filamentous fungi that results in rotting berries with high amounts of undesirable volatile acidity. Many insect species cause the initial grape berry damage that can lead to this disease, but most studies have focused on the role of fruit flies in facilitating symptoms and vectoring the microorganisms of this disease complex. Like fruit flies, social wasps are abundant in vineyards where they feed on ripe berries and cause significant damage, while also dispersing yeasts involved in wine fermentation. Despite this, their possible role in disease facilitation and dispersal of grape rots has not been explored. We tested the hypothesis that the paper wasp Polistes dominulus could facilitate grape sour rot in the absence of other insect vectors. Using marker gene sequencing we characterized the bacterial and fungal community of wild-caught adults. We used a sterilized foraging arena to determine if these wasps transfer viable microorganisms when foraging. We then tested if wasps harboring their native microbial community, or those inoculated with sour rot, had an effect on grape sour rot incidence and severity using a laboratory foraging arena. We found that all wasps harbor some portion of the sour rot microbial community and that they have the ability to transfer viable microorganisms when foraging. Foraging by inoculated and uninoculated wasps led to an increase in berry rot disease symptom severity and incidence. Our results indicate that paper wasps can facilitate sour rot diseases in the absence of other vectors and that the mechanism of this facilitation may include both increasing host susceptibility and transmitting these microbial communities to the grapes. Social wasps are

  9. Enzyme production by wood-rot and soft-rot fungi cultivated on corn fiber followed by simultaneous saccharification and fermentation.

    Science.gov (United States)

    Shrestha, Prachand; Khanal, Samir K; Pometto, Anthony L; van Leeuwen, J Hans

    2009-05-27

    This research aims at developing a biorefinery platform to convert lignocellulosic corn fiber into fermentable sugars at a moderate temperature (37 °C) with minimal use of chemicals. White-rot (Phanerochaete chrysosporium), brown-rot (Gloeophyllum trabeum), and soft-rot (Trichoderma reesei) fungi were used for in situ enzyme production to hydrolyze cellulosic and hemicellulosic components of corn fiber into fermentable sugars. Solid-substrate fermentation of corn fiber by either white- or brown-rot fungi followed by simultaneous saccharification and fermentation (SSF) with coculture of Saccharomyces cerevisiae has shown a possibility of enhancing wood rot saccharification of corn fiber for ethanol fermentation. The laboratory-scale fungal saccharification and fermentation process incorporated in situ cellulolytic enzyme induction, which enhanced overall enzymatic hydrolysis of hemi/cellulose components of corn fiber into simple sugars (mono-, di-, and trisaccharides). The yeast fermentation of the hydrolyzate yielded 7.8, 8.6, and 4.9 g ethanol per 100 g corn fiber when saccharified with the white-, brown-, and soft-rot fungi, respectively. The highest ethanol yield (8.6 g ethanol per 100 g initial corn fiber) is equivalent to 35% of the theoretical ethanol yield from starch and cellulose in corn fiber. This research has significant commercial potential to increase net ethanol production per bushel of corn through the utilization of corn fiber. There is also a great research opportunity to evaluate the remaining biomass residue (enriched with fungal protein) as animal feed.

  10. Peaches tree genetic divergence for brown rot reaction

    Directory of Open Access Journals (Sweden)

    Américo Wagner Júnior

    2011-10-01

    Full Text Available It was evaluated the genetic divergence in peach genotypes for brown rot reaction. It was evaluated 26 and 29 peach genotypes in the 2009/2010 and 2010/2011 production cycle, respectively. The experiment was carried out at the Laboratório de Fitossanidade, da UTFPR - Campus Dois Vizinhos. The experimental design was entirely randomized, considering each peach genotype a treatment, and it was use three replication of nine fruits. The treatment control use three replication of three peach. The fruit epidermis were inoculated individually with 0.15 mL of M. fructicola conidial suspension (1.0 x 10(5 spores mL-1. In the control treatment was sprayed with 0.15 mL of distilled water. The fruits were examined 72 and 120 hours after inoculation, and the incidence and severity disease were evaluated. These results allowed realized study for genetic divergence, used as dissimilarity measure the Generalized Mahalanobis distance. Cluster analysis using Tocher´s optimization method and distances in the plan were applied. There was smallest genetic divergence among peach trees evaluated for brown rot, what can difficult to obtain resistance in the genotypes.

  11. Transforming Fabry-Pérot resonances into a Tamm mode

    Science.gov (United States)

    Durach, Maxim; Rusina, Anastasia

    2012-12-01

    We propose an optical structure composed of two metal nanolayers enclosing a distributed Bragg reflector (DBR) mirror. The structure is an open photonic system whose bound modes are coupled to external radiation. We apply the special theoretical treatment based on inversion symmetry of the structure to classify its resonances. We show that the structure supports resonances transitional between Fabry-Pérot modes and Tamm plasmons. When the dielectric contrast of the DBR is removed these modes are a pair of conventional Fabry-Pérot resonances. They spectrally merge into a Tamm mode at high contrast. The optical properties of the structure in the frequency range of the DBR stop band, including highly beneficial 50% transmittivity through thick structures with sub-skin-depth metal films, are determined by the hybrid quasinormal modes of the open nonconservative structure under consideration. The results can find a broad range of applications in photonics and optoelectronics, including the possibility of coherent control over optical fields in the class of structures similar to the one proposed here.

  12. Brown rot on nuts of Castanea sativa Mill: an emerging disease and its causal agent

    Directory of Open Access Journals (Sweden)

    Maresi G

    2013-07-01

    Full Text Available The quality and quantity of nut production are fundamental to the economic viability of chestnut cultivation, yet recent reports indicate that severe damage due to moulds represents a significant problem for growers. We carried out an investigation of the agents of chestnut rot and internal fruit damage in three orchards in Italy. Black and brown rot, as well as insect damage, were found in all the areas examined. Brown rot appeared to be the main cause of damage, affecting 8% to 49% and 2% to 24% of nuts collected from the ground and from burrs, respectively. With respect to morphology and DNA sequencing analyses, fungal isolates obtained from brown rot were homologous with Gnomoniopsis sp. obtained from Dryocosmus kuriphilus (Yasumatsu galls and with Gnomoniopsis castanea and Gnomoniopsis smithogilvyi described on chestnut in Italy and Australia, respectively. The same fungus was also isolated from the bark of one- and two-years-old healthy shoots at each site, supporting the endophytic behaviour of this rot agent. Brown rot symptoms on nuts associated with Gnomoniopsis sp. corresponded with those previously described by several authors and referred to as Phoma or Phomopsis endogena, suggesting a relationship between these fungi and Gnomoniopsis sp. It is to notice that the escalation of brown rot damage in Italy followed several periods of drought and probably the recent invasion of D. kuriphilus, both stress factors for chestnut trees.

  13. Citrus Black Rot is Caused by Phylogenetically Distinct Lineages of Alternaria alternata.

    Science.gov (United States)

    Peever, T L; Carpenter-Boggs, L; Timmer, L W; Carris, L M; Bhatia, A

    2005-05-01

    ABSTRACT Phylogenetic analysis revealed that isolates of Alternaria alternata causing black rot of citrus were associated with six well-supported evolutionary lineages. Isolates recovered from brown spot lesions on Minneola tangelo, leaf spot lesions on rough lemon, and healthy citrus tissue and noncitrus hosts were related closely to isolates from black-rotted fruit. Phylogenies estimated independently from DNA sequence data from an endopolygalacturonase gene (endoPG) and two anonymous regions of the genome (OPA1-3 and OPA2-1) had similar topologies, and phylogenetic analysis was performed on the combined data set. In the combined phylogeny, isolates from diverse ecological niches on citrus and noncitrus hosts were distributed in eight clades. Isolates from all lineages, regardless of ecological or host association, caused black rot in fruit inoculation assays, demonstrating that small-spored Alternaria isolates associated with different ecological niches on citrus and other plant hosts are potential black rot pathogens. These data also indicated that the fungi associated with black-rotted fruit do not form a natural evolutionary group distinct from other Alternaria pathogens and saprophytes associated with citrus. The use of the name A. citri to describe fungi associated with citrus black rot is not justified and it is proposed that citrus black rot fungi be referred to as A. alternata.

  14. Neofusicoccum luteum associated with leaf necrosis and fruit rot of olives in New South Wales, Australia

    Directory of Open Access Journals (Sweden)

    V. Sergeeva

    2009-09-01

    Full Text Available Neofusicoccum luteum is reported for the first time from olives (Olea europaea, causing fruit rot and leaf necrosis. Affected fruits initially became brown with pycnidia developing on the surface, later drying out and becoming mummified. The fungus was shown to be pathogenic on both fruits and leaves. The association of Botryosphaeriaceae with rotting olive fruits in Mediterranean regions and in New South Wales, Australia indicates that these fungi play a significant role in fruit rots of olives and deserve greater attention.

  15. Variation in oxalate and oxalate decarboxylase production by six species of brown and white rot fungi

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Oliver, Jason; Howell, Caitlin;

    cell lumen where it quickly dissociates into hydrogen ions and oxalate, resulting in a pH decrease of the environment, and oxalate-cation complexes. Generally, brown rot fungi accumulate larger quantities of oxalic acid in the wood than white rot fungi. The amount of oxalic acid has been shown to vary...... of formic acid and CO2 (Makela et al., 2002). So far only a few species of brown rot fungi have been shown to accumulate this enzyme (Micales, 1995, Howell and Jellison, 2006).   The purpose of this study was to investigate the variation in the levels of soluble oxalate and total oxalate, in correlation...

  16. Releasing nitrogen from ammoniated lignin by white rot fungus cometabolizes environmental pollutants

    Institute of Scientific and Technical Information of China (English)

    LIN Lu; ZHAO De-qing; ZHOU Xian-tao; QIU Yu-gui; ZHANG Gan

    2003-01-01

    The nitrogen-modified lignocelluloses(NML) produced under oxic ammoniation was metabolized by white rot fungus, NH4+-N was released, NO3--N concentration was decreased and total nitrogen loss was blocked within incubation period. During releasing nitrogen from the metabolism of NML, white rot fungus cometabolized recalcitrant environmental pollutants and showed higher degradation capability. Results indicated that this NML complex colonized by white rot fungus might be effective with economic feasibility when they are applied into the vast field ecosystem, it might stabilize NH4+ nitrogen flux and bioremediate the polluted environmental sites.

  17. Afrokoko Roots

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Give us a little background information about Afrokoko Roots.How long have you been performing together?It's an international Afrobeat outfit that I founded in Beijing three years ago.I founded it in order to show Chinese people that Africa is beyond what they see and hear on TV.For the purpose of cultural exchange,I hope it can help the Chinese learn about African culture,music,fashion,history and much more.Our band features two dancers,two backup singers,two percussionists,four brass players,a keyboard player,a guitar player and a drummer- and me as the lead vocal,drummer and dancer,which makes for live performances that are equally exciting sonically as they are visually.We have been traveling around,and so far,we have toured and performed in many Chinese cities such as Dalian (Liaoning Province),Hohhot (Inner Mongolia Autonomous Region) and Haikou (Hainan Province).

  18. Production of a biocontrol agent for crucifers black rot disease

    Directory of Open Access Journals (Sweden)

    C.L. Luna

    2002-04-01

    Full Text Available Of nine epiphytic isolates of the genus Bacillus, only B. subtilis R14, B. pumilus C116, B. megaterium pv. cerealis RAB7, and B. cereus C210 showed antibiotic activity when tested in vitro against the bacterium Xanthomonas campestris pv. campestris LFR-3. Aiming product a biocontrol agent for black rot in crucifers, the production of B. subtilis R14 was evaluated in a batch bioreactor. Rapid growth was observed in a medium containing molasses and yeast extract as C-source and N-source, respectively. During the exponential growth phase, the specific growth rate was 1.2 h-1. A quick sporulation was also observed in a C/N well-balanced medium. After the sporulation phase, maximum viable spore concentrations around 10(9 CFU/mL were obtained. Preliminary sedimentation tests at different pH values showed better biomass separation efficiencies at low pH values.

  19. Comparison of ligninolytic activities of selected white-rot fungi

    Energy Technology Data Exchange (ETDEWEB)

    Waldner, R.; Leisola, M.S.A.; Fiechter, A.

    1988-10-01

    Six fast growing ligninolytic white-rot fungi were compared with Phanerochaete chrysosporium. The results showed that the fungi have similar ligninolytic systems, although minor differences exist. Like in P. chrysosporium the ligninolytic system could be induced by veratryl alcohol in Coriolus versicolor and Chrysosporium pruinosum. These three lignin peroxidase producing fungi were the fastest lignin degraders in stationary cultures, whereas in agitated cultures Bjerkandera adusta showed highest lignin degradation rates. Metabolites accumulating during the degradation of veratryl alcohol were analyzed and compared. Peroxidase production seems to be a common feature of all the tested fungi. Polyclonal antibodies against the lignin peroxidase with pl of 4.65 from P. chrysosporium reacted with the extracellular peroxidases of C. pruinosum, C. versicolor and B. adusta, but not with those of Pleurotus ostreatus.

  20. Synthetic dye decolorization capacity of white rot fungus Dichomitus squalens.

    Science.gov (United States)

    Eichlerová, Ivana; Homolka, Ladislav; Nerud, Frantisek

    2006-11-01

    The ability to decolorize eight chemically different synthetic dyes (Orange G, Amaranth, Orange I, Remazol Brilliant Blue R (RBBR), Cu-phthalocyanin, Poly R-478, Malachite Green and Crystal Violet) by the white rot fungus Dichomitus squalens was evaluated on agar plates. The fungus showed high decolorization capacity and was able to decolorize all dyes tested, but not to the same extent. Some of the dyes did not limit the decolorization capacity of the strain tested even at a concentration of 2g/l. The presence of the dyes in solid media reduced the mycelial growth rate of D. squalens; a positive correlation was found between the growth rate and the decolorization ability. Decolorization of Orange G and RBBR was studied also in liquid culture, where both dyes caused an enhancement of ligninolytic enzyme and overall hydrogen peroxide production and a decrease of biomass production. RBBR was removed to a higher extent than Orange G.

  1. Molecular Karyotype of the White Rot Fungus Pleurotus ostreatus

    Science.gov (United States)

    Larraya, Luis M.; Pérez, Gumer; Peñas, María M.; Baars, Johan J. P.; Mikosch, Thomas S. P.; Pisabarro, Antonio G.; Ramírez, Lucía

    1999-01-01

    The white rot fungus Pleurotus ostreatus is an edible basidiomycete with increasing agricultural and biotechnological importance. Genetic manipulation and breeding of this organism are restricted because of the lack of knowledge about its genomic structure. In this study, we analyzed the genomic constitution of P. ostreatus by using pulsed-field gel electrophoresis optimized for the separation of its chromosomes. We have determined that it contains 11 pairs of chromosomes with sizes ranging from 1.4 to 4.7 Mbp. In addition to chromosome separation, the use of single-copy DNA probes allowed us to resolve the ambiguities caused by chromosome comigration. When the two nuclei present in the dikaryon were separated by protoplasting, analysis of their karyotypes revealed length polymorphisms affecting various chromosomes. This is, to our knowledge, the clearest chromosome separation available for this species. PMID:10427028

  2. Saturnispora bothae sp. nov., isolated from rotting wood.

    Science.gov (United States)

    Morais, Camila G; Lara, Carla A; Borelli, Beatriz M; Cadete, Raquel M; Moreira, Juliana D; Lachance, Marc-André; Rosa, Carlos A

    2016-10-01

    Two strains representing a novel species of the genus Saturnispora were isolated from rotting wood samples collected in an Atlantic Rainforest site in Brazil. Analyses of the sequences of the D1/D2 domains of the rRNA gene showed that this novel species belongs to a subclade in the Saturnispora clade formed by Saturnispora sanitii, Saturnispora sekii, Saturnispora silvae and Saturnisporasuwanaritii. The novel species differed in D1/D2 sequences by 60 or more nucleotide substitutions from these species. The strains produced asci with one to four hemispherical ascospores. A novel species named Saturnispora bothae sp. nov. is proposed to accommodate these isolates. The type strain is UFMG-CM-Y292T (=CBS 13484T). The MycoBank number is MB 817127.

  3. resistance to post-harvest microbial rot in yam: integration of ...

    African Journals Online (AJOL)

    ACSS

    interactions of yam genotypes and storage methods for controlling internal rot in yam. Four local .... hazards and environmental pollution. Moreover, ... material. Dried maize stocks were then used to .... MSc Thesis, University of Ibadan,. Ibadan ...

  4. Control of Fusarium verticillioides, cause of ear rot of maize, by Pseudomonas fluorescens

    DEFF Research Database (Denmark)

    Nayaka, Siddaiah Chandra; Shankar, Akarere C. Udaya; Reddy, Munagala S.

    2009-01-01

    elicited considerable attention over the past decade owing to their association with animal disease syndromes. Hence, the present study was conducted to evaluate ecofriendly approaches by using a maize rhizosphere isolate of Pseudomonas fluorescens (Trev.) Mig. and its formulation to control ear rot......Abstract BACKGROUND: Maize is one of the staple food crops grown in India. Fusarium verticillioides (Sacc.) Nirenberg is the most important fungal pathogen of maize, associated with diseases such as ear rot and kernel rot. Apart from the disease, it is capable of producing fumonisins, which have....... verticillioides and the level of fumonisins to a maximum extent compared with the other treatments. CONCLUSION: The study demonstrates the potential role of P. fluorescens and its formulations in ear rot disease management. The biocontrol potential of this isolate is more suited for fumonisin reduction in maize...

  5. Production of lignocellulolytic enzymes from three white-rot fungi by ...

    African Journals Online (AJOL)

    jan

    2015-04-15

    Apr 15, 2015 ... development of a future commercial process for lignocellulolytic enzyme production. Key words: White-rot .... this collection by the National Coffee Research Center, Cenicafé, located in Chinchiná (Colombia). C. versicolor ...

  6. Evaluation of ear rot (Fusarium verticillioides) resistance and fumonisin accumulation in Italian maize inbred lines

    National Research Council Canada - National Science Library

    Carlotta Balconi; Nicola Berardo; Sabrina Locatelli; Chiara Lanzanova; Alessio Torri; Rita Redaelli

    2014-01-01

    .... In order to find maize germplasm sources of resistance to Fusarium ear rot, 34 Italian and six public inbred lines were evaluated by means of artificial inoculation in field experiments during 2009 and 2010...

  7. Synthetic fertilization reduction with compost and irrigation optimization on maize stem rot (Fusarium spp)

    National Research Council Canada - National Science Library

    Blanca E. López Valenzuela; Adolfo D. Armenta B; Miguel A. Apodaca S; Jesús del Rosario Ruelas I; Cesar A. Palacios Mondaca; Fernando A. Valenzuela Escoboza

    2014-01-01

    ...; being Sinaloa de major producer. The same crop over repeated seasons has favored disease proliferation of stem and ear rot mainly attributed to Fusarium spp which represents a risk potential so that growers are warned top pay close...

  8. CHARACTERIZATION OF WOOD DECAY BY ROT FUNGI USING COLORIMETRY AND INFRARED SPECTROSCOPY

    Directory of Open Access Journals (Sweden)

    Mírian de Almeida Costa

    2011-09-01

    Full Text Available Wood samples of marupá (Simarouba amara and andiroba (Carapa guianenis were submitted to Trametes versicolor (white rot and Gloeophylum trabeum (brown rot fungi attack. Colorimetry was used to determine the color of the wood before and after wood decaying fungi. To evaluate the changes in chemical compounds levels in the wood samples, the diffuse reflectance medium infrared spectroscopy was used. Both wood were non resistant against white rot fungus, while with brown rot attack andiroba was resistant and marupá was not. After Gloeophyllum trabeum attack both woods changed to a darken color, and after Trametes versicolor attack andiroba changed to a lighter color and marupá darkened slightly, The analysis showed a reduction in the peak intensity of cellulose, hemicellulose and lignin, for both species, after Trametes versicolor attack and a reduction in the peak intensity of cellulose after Gloeophyllum trabeum attack.

  9. Fungi associated with post-harvest rot of black plum (Vitex doniana) in Nigeria.

    Science.gov (United States)

    Eseigbe, D A; Bankole, S A

    The fungi associated with rot of Vitex doniana fruits (blackplum) were isolated and identified. Aspergillus niger, Botryodiplodia theobromae, Candida spp. Penicillium chrysogenum, Rhizopus stolonifer, Fusarium pallidoroseum F. oxysporum and Mucor mucedo were the primary rot causing fungi in contrast to Cladosporium herbarum and Mucor circinelloides which were just present as secondary colonizers. The rot fungi penetrated mainly through wounds and bruises on the surface of fruits. Mature green fruits were less susceptible to infection than half ripe and fully ripened red fruits. Optimum rot by pathogenic isolates occurred at 25-30 degrees C and relative humidity 72.5-100%. The results of investigation of influence of storage temperatures and relative humidity on the quality of uninoculated healthy fruits are presented and discussed.

  10. Trichothecene mycotoxins associated with potato dry rot caused by Fusarium graminearum

    National Research Council Canada - National Science Library

    Delgado, Javier A; Schwarz, Paul B; Gillespie, James; Rivera-Varas, Viviana V; Secor, Gary A

    2010-01-01

    .... Due to the uncertainty of trichothecene production in these tubers, a study was conducted to determine the accumulation and diffusion of trichothecenes in potato tubers affected with dry rot caused by F. graminearum...

  11. RESEARCH ARTICLES : Ethanol Production from Various Sugars and Cellulosic Biomass by White Rot Fungus Lenzites betulinus

    National Research Council Canada - National Science Library

    Kyung Hoan Im; ; Trung Kien Nguyen; Jaehyuk Choi; Tae Soo Lee

    2016-01-01

    .... It was found that the mycelia of white rot fungus Lenzites betulinus IUM 5468 produced ethanol from various sugars, including glucose, mannose, galactose, and cellobiose with a yield of 0.38, 0.26, 0.07...

  12. Ethanol Production from Various Sugars and Cellulosic Biomass by White Rot Fungus Lenzites betulinus

    National Research Council Canada - National Science Library

    Im, Kyung Hoan; Nguyen, Trung Kien; Choi, Jaehyuk; Lee, Tae Soo

    2016-01-01

    .... It was found that the mycelia of white rot fungus Lenzites betulinus IUM 5468 produced ethanol from various sugars, including glucose, mannose, galactose, and cellobiose with a yield of 0.38, 0.26, 0.07...

  13. Biodegradation of hazardous waste using white rot fungus: Project planning and concept development document

    Energy Technology Data Exchange (ETDEWEB)

    Luey, J.; Brouns, T.M.; Elliott, M.L.

    1990-11-01

    The white rot fungus Phanerochaete chrysosporium has been shown to effectively degrade pollutants such as trichlorophenol, polychlorinated biphenyls (PCBs), dioxins and other halogenated aromatic compounds. These refractory organic compounds and many others have been identified in the tank waste, groundwater and soil of various US Department of Energy (DOE) sites. The treatment of these refractory organic compounds has been identified as a high priority for DOE's Research, Development, Demonstration, Testing, and Evaluation (RDDT E) waste treatment programs. Unlike many bacteria, the white rot fungus P. chrysosporium is capable of degrading these types of refractory organics and may be valuable for the treatment of wastes containing multiple pollutants. The objectives of this project are to identify DOE waste problems amenable to white rot fungus treatment and to develop and demonstrate white rot fungus treatment process for these hazardous organic compounds. 32 refs., 6 figs., 7 tabs.

  14. Combined effects of biocontrol agents and soil amendments on soil microbial populations, plant growth and incidence of charcoal rot of cowpea and wilt of cumin

    Directory of Open Access Journals (Sweden)

    Vijeta SINGH

    2012-09-01

    Full Text Available Field experiments were conducted for 2 years to determine the effectiveness of combined use of two biocontrol agents, Bacillus firmus and Aspergillus versicolor for control of Macrophomina phaseolina induced charcoal rot of cowpea and Fusarium oxysporum f. sp. cumini induced wilt of cumin. The lowest level of plant mortality (3‒4% due to charcoal rot of cowpea was recorded when bacterium coated seeds were sown in radish compost amended soil compared to the non-amended soil (13.8‒20.5%, but this was not significantly better than some other treatments. Cowpea roots from B. firmus coated seeds had better nodulation than any of the individual A. versicolor treatments. Although B. firmus coated seeds + A. versicolor + farmyard manure resulted in maximum nodulation this was not significantly different to B. firmus seed coating. Root colonization by the combined biocontrol agent treatments was better than the individual biocontrol agent treatments. Combining A. versicolor with farmyard manure supported the maximum populations of total fungi and actinomycetes. In both winter seasons, the lowest incidence of wilt (1.0‒5.2% on cumin was recorded when A. versicolor was amended with neem compost compared to the non-amended soil (5.7‒10.5%. Maximum colonization of A. versicolor on roots was observed in B. firmus + A. versicolor + farmyard manure amended plots. During both years, the treatment combination of A. versicolor in neem compost amended plots resulted in maximum populations of fungi, bacteria and A. versicolor in the soil, which was greater than in the non-amended soil. Significant increases in disease control were not recorded after single or repeated delivery of A. versicolor. These results suggest that combining B. firmus as seed coatings with A. versicolor as soil applications gives improved control of M. phaseolina and Fusarium induced diseases on legume and seed spice crops in arid soils.

  15. Effectiveness of Neutral Electrolyzed Water on Incidence of Fungal Rot on Tomato Fruits ( Solanum lycopersicum L.).

    Science.gov (United States)

    Vásquez-López, Alfonso; Villarreal-Barajas, Tania; Rodríguez-Ortiz, Gerardo

    2016-10-01

    We assessed the effect of neutral electrolyzed water (NEW) on the incidence of rot on tomato ( Solanum lycopersicum L.) fruits inoculated with Fusarium oxysporum , Galactomyces geotrichum , and Alternaria sp. at sites with lesions. The inoculated fruits were treated with NEW at 10, 30, and 60 mg liter(-1) active chlorine, with copper oxychloride fungicide, and with sterile distilled water (control) for 3, 5, and 10 min. In the experiment with F. oxysporum , 50 to 80% of the control fruits and 50 to 60% of the fruits treated with the fungicide exhibited symptoms of rot at the inoculated sites. The lowest incidence recorded was 30% for fruits treated with NEW at 60 mg liter(-1) active chlorine with an immersion time of 5 min. In the experiment with G. geotrichum , incidence of rot on control fruits was 70 to 90%, and for treatment with fungicide rot incidence was 50 to 90%. NEW at 60 mg liter(-1) active chlorine significantly reduced incidence of symptomatic fruit: only 30% of the inoculated fruits washed for 5 min had damage from rot. In the experiment with Alternaria sp., 60 to 90% of the fruits in the control group and 60 to 70% of the fruits in the fungicide group were symptomatic. The lowest incidence was recorded for the treatment in which the fruits were submerged in NEW with 60 mg liter(-1) active chlorine for 3 min. In this group, 40 to 50% of the fruits exhibited symptoms of rot. These results were obtained 8 days after inoculation. NEW, with 60 mg liter(-1) active chlorine, significantly reduced incidence of rot symptoms on fruits inoculated with one of the experimental fungi relative to the control (P ≤ 0.05). NEW at 60 mg liter(-1) is effective in the control of fungal rot in tomatoes.

  16. First Report of Myrothecium roridum Causing Leaf and Stem Rot Disease on Peperomia quadrangularis in Korea.

    Science.gov (United States)

    Han, Kyung-Sook; Choi, Seung-Kook; Kim, Hyeong-Hwan; Lee, Sung-Chan; Park, Jong-Han; Cho, Myoung-Rae; Park, Mi-Jeong

    2014-06-01

    In 2010, symptoms of leaf and stem rot were observed on potted plants (Peperomia quadrangularis) in a greenhouse in Yongin, Korea. The causative pathogen was identified as Myrothecium roridum based on morphological data, internal transcribed spacer sequence analysis, and pathogenicity test. To our knowledge, this is the first report of M. roridum causing leaf and stem rot disease on P. quadrangularis in Korea and elsewhere worldwide.

  17. Distribution and prevalence of crown rot pathogens affecting wheat crops in southern Chile

    Directory of Open Access Journals (Sweden)

    Ernesto Moya-Elizondo

    2015-03-01

    Full Text Available Crown rot pathogens are associated with higher losses for wheat crop farmers, but information about the distribution and prevalence of these pathogens in Chile is inadequate. Distribution and prevalence of wheat (Triticum aestivum L. crown rot pathogens were examined in a survey of 48 commercial fields from December 2011 to February 2012 in southern Chile. These fields were located between Collipulli (37°56'00" S; 72°26'39" W and Purranque (40°50'30" S; 73°22'03" W. Severity of crown rot disease was determined through visual assessment of the first internode of 20 tillers obtained from each field. Incidence of crown rot pathogens per field was determined by plating the 20 tillers on Petri plates with 20% potato dextrose agar amended with lactic acid (aPDA medium. Resulting fungal colonies from monoxenic culture were identified by morphological or molecular-assisted identification. Severity of crown rot varied between 11.3% and 80% for individual fields. Culture plate analysis showed 72.2% of stems were infected with some fungus. Fusarium avenaceum, F. graminearum, and F. culmorum, pathogens associated with Fusarium crown rot disease were isolated from 13.5% of tillers. Gaeumannomyces graminis, causal agent of take-all disease in cereals, was isolated from 11.1% of culms. Phaeosphaeria sp., an endophyte and possibly a non-pathogenic fungus, was isolated from 13.9% of tillers. Pathogenic fungi such as Rhizoctonia spp. and Microdochium nivale, other saprophyte, and several unidentified non-sporulating fungi were isolated at frequencies lower than 3% of the total. Fusarium crown rot and take-all were the most prevalent and distributed crown rot diseases present in wheat crops in southern Chile.

  18. No Reported Species, Botrytis aclada Causing Gray Mold Neck Rot Disease on Onion Bulbs in Korea

    OpenAIRE

    Hwang, Sun–Kyoung; Lee, Seung–Yeol; Back, Chang–Gi; Kang, In–Kyu; Lee, Hyang–Burm; Jung, Hee-Young; Ohga, Shoji; Oga, Shoji

    2016-01-01

    Gray mold neck rot was observed on onion bulbs (Allium cepa L.) in low–temperature warehouses in Changnyeong–gun, Korea. The causative pathogen was isolated from rotted onion bulb lesions and identified as Botrytis aclada based on morphological and culture characteristics, the sequences of three nuclear genes (G3PDH, HSP60, and RPB2), and polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) for Botrytis spp. identification. Although onion gray mold disease caused by B...

  19. Trichothecene mycotoxins associated with potato dry rot caused by Fusarium graminearum.

    Science.gov (United States)

    Delgado, Javier A; Schwarz, Paul B; Gillespie, James; Rivera-Varas, Viviana V; Secor, Gary A

    2010-03-01

    Fusarium graminearum, a known producer of trichothecene mycotoxins in cereal hosts, has been recently documented as a cause of dry rot of potato tubers in the United States. Due to the uncertainty of trichothecene production in these tubers, a study was conducted to determine the accumulation and diffusion of trichothecenes in potato tubers affected with dry rot caused by F. graminearum. Potato tubers of cv. Russet Burbank were inoculated with 14 F. graminearum isolates from potato, sugar beet, and wheat and incubated at 10 to 12 degrees C for 5 weeks to determine accumulation of trichothecenes in potato tubers during storage. Twelve of the isolates were classified as deoxynivalenol (DON) genotype and two isolates were as nivalenol (NIV) genotype. Trichothecenes were detected only in rotted tissue. DON was detected in all F. graminearum DON genotype isolates up to 39.68 microg/ml in rotted potato tissue. Similarly, both NIV genotype isolates accumulated NIV in rotted potato tissue up to 18.28 microg/ml. Interestingly, isolates classified as genotype DON accumulated both DON and NIV in the dry rot lesion. Potato tubers were then inoculated with two isolates of F. graminearum chemotype DON and incubated up to 7 weeks at 10 to 12 degrees C and assayed for DON diffusion. F. graminearum was recovered from >53% of the isolations from inoculated tubers at 3 cm distal to the rotted tissue after 7 weeks of incubation but DON was not detected in the surrounding tissue. Based in this data, the accumulation of trichothecenes in the asymptomatic tissue surrounding dry rot lesions caused by F. graminearum is minimal in cv. Russet Burbank potato tubers stored for 7 weeks at customary processing storage temperatures.

  20. Relation between combustion heat and chemical wood composition during white and brown rot

    Energy Technology Data Exchange (ETDEWEB)

    Dobry, J.; Dziurzynski, A.; Rypacek, V.

    1986-01-01

    Samples of beech and spruce wood were incubated with the white rot fungi Pleurotus ostreatus and Lentinus tigrinus and the brown rot fungi Fomitopsis pinicola and Serpula lacrymans (S. lacrimans) for four months. Decomposition (expressed as percent weight loss) and amounts of holocellulose, lignin, humic acids (HU), hymatomelanic acids (HY) and fulvo acids (FU) were determined and expressed in weight percent. Combustion heat of holocellulose and lignin was determined in healthy wood and in specimens where decomposition was greater than 50%. During white rot decomposition, combustion heat was unchanged even at high decomposition and the relative amounts of holocellulose and lignin remained the same. Total amounts of HU, HY and FU increased during the initial stages and stabilized at 20%. The content of HU plus HY was negligible even at the highest degree of decomposition. During brown rot decomposition, combustion heat was unchanged only in the initial stages, it increased continously with increasing rot. Lignin content was unchanged in the initial stages and increased after 30% weight loss. Total amounts of HU, HY and FU increased continuously, reaching higher values than in white rot decomposition; there were differences between the two species. Biosynthesis of HU plus HY began when weight loss reached 30%; there were differences in absolute and relative amounts between species. 24 references.

  1. Two genes conferring resistance to Pythium stalk rot in maize inbred line Qi319.

    Science.gov (United States)

    Song, Feng-Jing; Xiao, Ming-Gang; Duan, Can-Xing; Li, Hong-Jie; Zhu, Zhen-Dong; Liu, Bao-Tao; Sun, Su-Li; Wu, Xiao-Fei; Wang, Xiao-Ming

    2015-08-01

    Stalk rots are destructive diseases in maize around the world, and are most often caused by the pathogen Pythium, Fusarium and other fungi. The most efficient management for controlling stalk rots is to breed resistant cultivars. Pythium stalk rot can cause serious yield loss on maize, and to find the resistance genes from the existing germplasm is the basis to develop Pythium-resistance hybrid lines. In this study, we investigated the genetic resistance to Pythium stalk rot in inbred line Qi319 using F2 and F2:3 population, and found that the resistance to Pythium inflatum in Qi319 was conferred by two independently inherited dominant genes, RpiQI319-1 and RpiQI319-2. Linkage analysis uncovered that the RpiQI319-1 co-segregated with markers bnlg1203, and bnlg2057 on chromosome 1, and that the RpiQI319-2 locus co-segregated with markers umc2069 and bnlg1716 on chromosome 10. The RpiQI319-1 locus was further mapped into a ~500-kb interval flanked by markers SSRZ33 and SSRZ47. These results will facilitate marker-assisted selection of Pythium stalk rot-resistant cultivars in maize breeding. To our knowledge, this is the first report on the resistance to P. inflatum in the inbred line Qi319, and is also the first description of two independently inherited dominant genes conferring the resistance of Pythium stalk rot in maize.

  2. Neuropharmacological properties of Trichosanthes dioica root

    Institute of Scientific and Technical Information of China (English)

    Sanjib Bhattacharya; Pallab Kanti Haldar

    2013-01-01

    AIM:Trichosanthes dioica Roxb.(Cucurbitaceae),commonly known as pointed gourd in English,is a dioecious climber grown widely in the Indian subcontinent.Traditionally,this plant has been used in India for several medicinal purposes.The present study aimed to evaluate certain neuropharmacological properties of the hydroalcoholic extract of T.dioica root (TDA) in experimental animal models.METHODS:TDA (at 100 and 200 mg.kg-1 body weight,p.o.) was evaluated for anti-noeiceptive activity by the acetic acid-induced writhing and tail flick methods.Locomotor depressant activity was measured by means of an actophotometer.Skeletal muscle relaxant effects were evaluated by using a rots-rod apparatus,and the sedative potentiating property by a phenobarbitone-induced sleep potentiation study.RESULTS:The results of the present study revealed significant (P < 0.001) and dose dependent anti-nociceptive,locomotor depressant,muscle relaxant,and sedative potentiating effects of TDA,demonstrating its depressant action on the central nervous system (CNS).CONCLUSION:From the present study,it can be concluded that T.dioica root possessed prominent anti-nociceptive,as well as depressant,action on the CNS,as manifested by these important neuropharmacological properties in mice.

  3. Electrical Imaging of Roots and Trunks

    Science.gov (United States)

    Al Hagrey, S.; Werban, U.; Meissner, R.; Ismaeil, A.; Rabbel, W.

    2005-05-01

    We applied geoelectric and GPR techniques to analyze problems of botanical structures and even processes, e.g., mapping root zones, internal structure of trunks, and water uptake by roots. The dielectric nature of root zones and trunks is generally a consequence of relatively high moisture content. The electric method, applied to root zones, can discriminate between old, thick, isolated roots (high resistivity) and the network of young, active, and hydraulically conductive zones (low resistivity). Both types of roots show low radar velocity and a strong attenuation caused by the dominant effect of moisture (high dielectric constant) on the electromagnetic wave propagation. Single root branches could be observed in radargrams by their reflection and diffraction parabolas. We have perfected the inversion method for perfect and imperfect cylindrical objects, such as trunks, and developed a new multielectrodes (needle or gel) ring array for fast applications on living trees and discs. Using synthetic models we tested the technique successfully and analyzed it as a function of total electrode number and configuration. Measurements at a trunk show a well established inverse relationship between the imaged resistivity and the moisture content determined from cores. The central resistivity maximum of healthy trees strongly decreases toward the rim. This agrees with the moisture decrease to the outside where active sap flow processes take place. Branching, growth anomalies (new or old shoots) and meteorological effects (sunshine and wind direction) lead to deviations of the concentric electric structure. The strongest anomalies are related to infections causing wet, rotting spots or cavities. The heartwood resistivity is highest in olive and oak trunks, intermediate in young fruit trees and lowest in cork oak trunks that are considered to be anomalously wet. Compared to acoustic tomography our electric technique shows a better resolution in imaging internal ring structures

  4. Plant growth-promotion (PGP) activities and molecular characterization of rhizobacterial strains isolated from soybean (Glycine max L. Merril) plants against charcoal rot pathogen, Macrophomina phaseolina.

    Science.gov (United States)

    Choudhary, D K

    2011-11-01

    Charcoal rot disease, caused by the fungus Macrophomina phaseolina, leads to significant yield losses of soybean crops. One strategy to control charcoal rot is the use of antagonistic, root-colonizing bacteria. Rhizobacteria A(5)F and FPT(7)21 and Pseudomonas sp. strain GRP(3) were characterized for their plant growth-promotion activities against the pathogen. Rhizobacterium FPT(7)21 exhibited higher antagonistic activity against the pathogen on dual plate assay compared to strain A(5)F and GRP(3). FPT(7)21 and GRP(3) gave decreased disease intensity in terms of average number of pathogen-infested plants. Lipoxygenase (LOX), phenylalanine ammonia-lyase (PAL), and peroxidase (POD) activities were estimated in extracts of plants grown from seeds that were treated with rhizobacteria, and inoculated with spore suspension of M. phaseolina. The activity of these enzymes after challenge with the test pathogen increased. Strains FPT(7)21 and GRP(3) exhibited maximum increases in LOX, PAL and POD activity (U mg(-1) fresh leaf wt) compared to strain A(5)F.

  5. Structure-based functional characterization of repressor of toxin (Rot), a central regulator of Staphylococcus aureus virulence.

    Science.gov (United States)

    Killikelly, April; Benson, Meredith A; Ohneck, Elizabeth A; Sampson, Jared M; Jakoncic, Jean; Spurrier, Brett; Torres, Victor J; Kong, Xiang-Peng

    2015-01-01

    Staphylococcus aureus is responsible for a large number of diverse infections worldwide. In order to support its pathogenic lifestyle, S. aureus has to regulate the expression of virulence factors in a coordinated fashion. One of the central regulators of the S. aureus virulence regulatory networks is the transcription factor repressor of toxin (Rot). Rot plays a key role in regulating S. aureus virulence through activation or repression of promoters that control expression of a large number of critical virulence factors. However, the mechanism by which Rot mediates gene regulation has remained elusive. Here, we have determined the crystal structure of Rot and used this information to probe the contribution made by specific residues to Rot function. Rot was found to form a dimer, with each monomer harboring a winged helix-turn-helix (WHTH) DNA-binding motif. Despite an overall acidic pI, the asymmetric electrostatic charge profile suggests that Rot can orient the WHTH domain to bind DNA. Structure-based site-directed mutagenesis studies demonstrated that R(91), at the tip of the wing, plays an important role in DNA binding, likely through interaction with the minor groove. We also found that Y(66), predicted to bind within the major groove, contributes to Rot interaction with target promoters. Evaluation of Rot binding to different activated and repressed promoters revealed that certain mutations on Rot exhibit promoter-specific effects, suggesting for the first time that Rot differentially interacts with target promoters. This work provides insight into a precise mechanism by which Rot controls virulence factor regulation in S. aureus.

  6. In Vitro Antagonism of Bacillus thuringiensis NCIM2130 against Sclerotium rolfsii Sacc., A Stem Rot Pathogen of Groundnut

    OpenAIRE

    Ravindra. R. Rakh; Laxman S. Raut; Anand V. Manwar

    2016-01-01

    Stem rot is one of the most drastic diseases of groundnut that cause major crop loss. Stem rot pathogen of groundnut, Sclerotium rolfsii, was isolated from the infected groundnut stem. Present investigation was started to search for effective biocontrol agent against Sclerotium rolfsii. To find effective biocontrol agent, 120 Bacillus spp. isolated from various rhizospheric soils of healthy plants, screened in vitro against the stem rot pathogen by dual culture technique. Out of these Bacillu...

  7. ROOT Reference Documentation

    CERN Document Server

    Fuakye, Eric Gyabeng

    2017-01-01

    A ROOT Reference Documentation has been implemented to generate all the lists of libraries needed for each ROOT class. Doxygen has no option to generate or add the lists of libraries for each ROOT class. Therefore shell scripting and a basic C++ program was employed to import the lists of libraries needed by each ROOT class.

  8. 河西灌区马铃薯茎基腐病的发生规律与防治技术研究%Occurrence and control of potato crown rot in irrigated areas of Hexi Corridor

    Institute of Scientific and Technical Information of China (English)

    雷玉明; 张建朝; 费永祥; 邢会琴; 张建文

    2011-01-01

    本文首次报道马铃薯茎基腐病在田间表现为立枯型、萎蔫型、根腐型、黄化型4种症状类型,一般在苗期至现蕾期、开花期至结薯期为发病高峰期;明确了河西灌区种植的大多数品种对茎基腐病无明显抗性;发病程度与多种因素有关,灰钙土发病较重,其次为壤土,沙土发病较轻;土壤pH与含水量较高发病重;植株密度较高发病重;连作年限越长发病越重;与油菜、茄科蔬菜连作发病较重;高温有利于该病发生;经药剂种薯、土壤、灌根处理表明:以代森锰锌、菌核净和敌磺钠种薯和土壤处理,代森锰锌、井·1亿活枯草芽孢菌、菌核净灌根处理,防效达50.3%~65.9%.%The symptoms of potato crown rot were recorded for the first time, i.e.damping-off, wilt, root rot and yellowing.The disease severely occurred during seedling, budding, flowering and fruiting stages.No significant resistance to crown rot had been observed in most cultivars.The effect of soil texture on potato crown rot was that the disease index was highest in sierozem, lower in clay loam and lowest in sandy soils.The disease occurrence was more serious in alkaline soils with high water content than in weak acid or neutral soils with low water content.High density caused serious disease.The longer the consecutive cropping lasted, the more seriously the disease occurred.Rape-potato and solanaceae-potato cropping also caused more serious disease.High temperature and moisture were good for potato crown rot occurrence.Control tests indicated that the efficacy of mancozeb,dimetachlone and fenaminosulf with seed treatment and soil treatment, and mancozeb, dimetachlone and brevibacterium with root-irrigating treatment were between 50.3% and 65.9%.

  9. Enhanced bioprocessing of lignocellulose: Wood-rot fungal saccharification and fermentation of corn fiber to ethanol

    Science.gov (United States)

    Shrestha, Prachand

    This research aims at developing a biorefinery platform to convert corn-ethanol coproduct, corn fiber, into fermentable sugars at a lower temperature with minimal use of chemicals. White-rot (Phanerochaete chrysosporium), brown-rot (Gloeophyllum trabeum) and soft-rot (Trichoderma reesei) fungi were used in this research to biologically break down cellulosic and hemicellulosic components of corn fiber into fermentable sugars. Laboratory-scale simultaneous saccharification and fermentation (SSF) process proceeded by in-situ cellulolytic enzyme induction enhanced overall enzymatic hydrolysis of hemi/cellulose from corn fiber into simple sugars (mono-, di-, tri-saccharides). The yeast fermentation of hydrolyzate yielded 7.1, 8.6 and 4.1 g ethanol per 100 g corn fiber when saccharified with the white-, brown-, and soft-rot fungi, respectively. The highest corn-to-ethanol yield (8.6 g ethanol/100 g corn fiber) was equivalent to 42 % of the theoretical ethanol yield from starch and cellulose in corn fiber. Cellulase, xylanase and amylase activities of these fungi were also investigated over a week long solid-substrate fermentation of corn fiber. G. trabeum had the highest activities for starch (160 mg glucose/mg protein.min) and on day three of solid-substrate fermentation. P. chrysosporium had the highest activity for xylan (119 mg xylose/mg protein.min) on day five and carboxymethyl cellulose (35 mg glucose/mg protein.min) on day three of solid-substrate fermentation. T. reesei showed the highest activity for Sigma cell 20 (54.8 mg glucose/mg protein.min) on day 5 of solid-substrate fermentation. The effect of different pretreatments on SSF of corn fiber by fungal processes was examined. Corn fiber was treated at 30 °C for 2 h with alkali [2% NaOH (w/w)], alkaline peroxide [2% NaOH (w/w) and 1% H2O 2 (w/w)], and by steaming at 100 °C for 2 h. Mild pretreatment resulted in improved ethanol yields for brown- and soft-rot SSF, while white-rot and Spezyme CP SSFs showed

  10. FTIR and XPS analysis of the changes in bamboo chemical structure decayed by white-rot and brown-rot fungi

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Guoqi [College of Engineering and Technology, Northeast Forestry University, Harbin 150040 (China); Wang, Lihai, E-mail: xu12nefu@sina.cn [College of Engineering and Technology, Northeast Forestry University, Harbin 150040 (China); Liu, Junliang [Research Institute of Wood Industry, Chinese Academy of Forestry, Beijing 100091 (China); Wu, Jinzhuo [College of Engineering and Technology, Northeast Forestry University, Harbin 150040 (China)

    2013-09-01

    In order to investigate different types of decay mechanisms in bamboo (Phyllostachys edulis), the chemical structure and microstructure of bamboo samples decayed by P. chrysosporium (White-rot) and G. trabeum (Brown-rot) for 12 weeks were studied. The analysis methods include fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron spectroscopy (SEM). By using the SEM method, it was found that attacks to parenchyma cells and places near the inner skin of bamboo were the most frequent and the vessels were the primary paths for the spread of mycelium in the bamboo. FTIR and XPS results showed that the crystallinity (I1425/I896) of bamboo decreased after being decayed by these two fungi and the crystalline cellulose in bamboo was degraded. The white-rot P. chrysosporium had stronger degradability on lignin compared to hemicellulose and cellulose in bamboo. And the brown-rot G. trabeum had preferential degradability on hemicellulose fraction over cellulose and lignin. Oxidation and hydrolysis surface reactions occurred during the process of decay, but the reaction rates for cellulose and lignin were different.

  11. Identification of naphthalene metabolism by white rot fungus Pleurotus eryngii.

    Science.gov (United States)

    Hadibarata, Tony; Teh, Zee Chuang; Rubiyatno; Zubir, Meor Mohd Fikri Ahmad; Khudhair, Ameer Badr; Yusoff, Abdull Rahim Mohd; Salim, Mohd Razman; Hidayat, Topik

    2013-10-01

    The use of biomaterials or microorganisms in PAHs degradation had presented an eye-catching performance. Pleurotus eryngii is a white rot fungus, which is easily isolated from the decayed woods in the tropical rain forest, used to determine the capability to utilize naphthalene, a two-ring polycyclic aromatic hydrocarbon as source of carbon and energy. In the meantime, biotransformation of naphthalene to intermediates and other by-products during degradation was investigated in this study. Pleurotus eryngii had been incubated in liquid medium formulated with naphthalene for 14 days. The presence of metabolites of naphthalene suggests that Pleurotus eryngii begin the ring cleavage by dioxygenation on C1 and C4 position to give 1,4-naphthaquinone. 1,4-Naphthaquinone was further degraded to benzoic acid, where the proposed terepthalic acid is absent in the cultured extract. Further degradation of benzoic acid by Pleurotus eryngii shows the existence of catechol as a result of the combination of decarboxylation and hydroxylation process. Unfortunately, phthalic acid was not detected in this study. Several enzymes, including manganese peroxidase, lignin peroxidase, laccase, 1,2-dioxygenase and 2,3-dioxygenase are enzymes responsible for naphthalene degradation. Reduction of naphthalene and the presence of metabolites in liquid medium showed the ability of Pleurotus eryngii to utilize naphthalene as carbon source instead of a limited glucose amount.

  12. Biodegradation of ciprofloxacin by white rot fungus Pleurotus ostreatus.

    Science.gov (United States)

    Singh, Sushil Kumar; Khajuria, Robinka; Kaur, Loveleen

    2017-05-01

    Unrestricted and reckless use of antibiotics has resulted in their accumulation in environment. This, in turn, has led to the emergence of multiple drug-resistant microbes. The present study focuses on degradation of ciprofloxacin (CIP) by an edible white rot fungus Pleurotus ostreatus. Effect of CIP was determined on radial growth and biomass of P. ostreatus. Titrimetric and spectrophotometric assays were carried out to assess the degrading potential of P. ostreatus towards CIP. It was found that CIP has a stimulatory effect on growth and enzyme activity of P. ostreatus. Maximum enzyme (glucanase, ligninases, laccase) production was observed at the highest concentration of CIP (500 ppm). Antibiotic degradation of about 68.8, 94.25 and 91.34% was estimated after 14 days of incubation at 500 ppm CIP using Titrimetric, Indigo carmine and Methyl orange assay, respectively. Degradation of CIP was further validated by high performance liquid chromatography (HPLC) and microbiological analysis. HPLC analysis revealed 95.07% degradation while microbiological test also exhibited a decreased antimicrobial activity of degraded products against Escherichia coli, Staphylococcus aureus and Streptococcus pyogenes. To the best of our knowledge, this is the first study wherein P. ostreatus was used for the degradation of ciprofloxacin.

  13. Microsomal transformation of organophosphorus pesticides by white rot fungi.

    Science.gov (United States)

    Jauregui, Juan; Valderrama, Brenda; Albores, Arnulfo; Vazquez-Duhalt, Rafael

    2003-12-01

    The enzymatic mechanism for the transformation of organophosphorus pesticides (OPPs) by different white-rot fungi strains was studied. With the exception of Ganoderma applanatum 8168, all strains from a collection of 17 different fungi cultures were able to deplete parathion. Three strains showing the highest activities were selected for further studies: Bjerkandera adusta 8258, Pleurotus ostreatus 7989 and Phanerochaete chrysosporium 3641. These strains depleted 50 to 96% of terbufos, azinphos-methyl, phosmet and tribufos after four-days exposure to the pesticides. In order to identify the cellular localization of the transformation activity, the extracellular and microsomal fractions of Pleuronts ostreatus 7989 were evaluated in vitro. While the activities of ligninolytic enzymes (lignin peroxidase, manganese peroxidase and laccase) were detected in the extracellular fraction, no enzymatic modification of any of the five pesticides tested could be found, suggesting the intracellular origin of the transformation activity. In accordance with this observation the microsomal fraction was found able to transform three OPPs with the following rates: 10 micromol mg prot(-1) h(-1) for phosmet, 5.7 micromol mg prot(-1) h(-1) for terbufos, and 2.2 micromol mg prot(-1) h(-1) for azinphos-methyl. The products from these reactions and from the transformation of trichlorfon and malathion, were identified by mass-spectrometry. These results, supported by specific inhibition experiments and the stringent requirement for NADPH during the in vitro assays suggest the involvement of a cytochrome P450.

  14. Production of Dissolved Organic Matter During Fungal Wood Rot Decay

    Science.gov (United States)

    Filley, T. R.; Jellison, J.; Goodell, B.; Kelley, S.; Davis, M.

    2002-12-01

    Dissolved organic matter mediates numerous biogeochemical processes in soil systems impacting subsurface microbial activity, redox chemistry, soil structure, and carbon and nitrogen sequestration. The structure and chemistry of DOM is a function of the inherited chemistry of the source material, the type of microbial action that has occurred, and selective interaction with mineral substrates. The type of fungal decomposition imparted to woody tissue is a major factor in determining the nature of DOM in forest soils. In order to investigate the relationship between fungal decomposition and the nature of DOM in coniferous forest soils we conducted 32-week inoculation studies on spruce sapwood with basidiomycete brown-rot wood decay fungi where leachable dissolved and colloidal organic matter was separated from decayed residue. A detailed examination of the organic fractions was conducted using 13C-labeled tetramethylammonium hydroxide thermochemolysis, solid-state 13C-NMR, and electrospray mass spectrometry. The progressive stages of microbial decay (cellulolytic and ligninolytic) were manifested in the chemical composition of the DOM which showed an evolution from a composition initially polysaccharide rich to one dominated by mildly oxidized and demethylated lignin. Upon removal of all polysaccharides at 16 weeks the DOM (up to 10% by weight of the original tissue) looked chemically distinct from the degraded residue

  15. Multilocus phylogeny reveals an association of agriculturally important Fusarium solani species complex (FSSC) 11, and clinically important FSSC 5 and FSSC 3 + 4 with soybean roots in the north central United States.

    Science.gov (United States)

    Chitrampalam, P; Nelson, B

    2016-02-01

    The Fusarium solani species complex (FSSC) includes important root pathogens of soybean in the United States, but the evolutionary lineages associated with soybean root rot are unknown. A multilocus phylogeny based on 93 isolates from soybean and pea roots from North Dakota and Minnesota revealed that root rot was associated with three known phylogenetic species, FSSC 3 + 4 (=Fusarium falciforme) (3 % of isolates), FSSC 5 (60 %), FSSC 11 (34 %), and one unknown species, FSSC X (2 %). Of these species FSSC 5 and FSSC 3 + 4 are clinically important while FSSC 11 is a plant pathogen. Isolates from FSSC 11 were pathogenic on soybean, dry bean, pea and lentil, and did not grow at 37 °C. However, isolates from FSSC 5 were weakly to non-pathogenic, but grew at 37 °C. Isolates from both FSSC 5 and FSSC 11 were highly resistant to fludioxonil in vitro. This is the first study revealing the pathogenic robustness of FSSC 11 in causing root rot among Fabaceae crops and also the association of clinically important members of the FSSC with roots of a widely grown field crop in the United States.

  16. Developmental and Metabolic Plasticity of White-Skinned Grape Berries in Response to Botrytis cinerea during Noble Rot.

    Science.gov (United States)

    Blanco-Ulate, Barbara; Amrine, Katherine C H; Collins, Thomas S; Rivero, Rosa M; Vicente, Ariel R; Morales-Cruz, Abraham; Doyle, Carolyn L; Ye, Zirou; Allen, Greg; Heymann, Hildegarde; Ebeler, Susan E; Cantu, Dario

    2015-12-01

    Noble rot results from exceptional infections of ripe grape (Vitis vinifera) berries by Botrytis cinerea. Unlike bunch rot, noble rot promotes favorable changes in grape berries and the accumulation of secondary metabolites that enhance wine grape composition. Noble rot-infected berries of cv Sémillon, a white-skinned variety, were collected over 3 years from a commercial vineyard at the same time that fruit were harvested for botrytized wine production. Using an integrated transcriptomics and metabolomics approach, we demonstrate that noble rot alters the metabolism of cv Sémillon berries by inducing biotic and abiotic stress responses as well as ripening processes. During noble rot, B. cinerea induced the expression of key regulators of ripening-associated pathways, some of which are distinctive to the normal ripening of red-skinned cultivars. Enhancement of phenylpropanoid metabolism, characterized by a restricted flux in white-skinned berries, was a common outcome of noble rot and red-skinned berry ripening. Transcript and metabolite analyses together with enzymatic assays determined that the biosynthesis of anthocyanins is a consistent hallmark of noble rot in cv Sémillon berries. The biosynthesis of terpenes and fatty acid aroma precursors also increased during noble rot. We finally characterized the impact of noble rot in botrytized wines. Altogether, the results of this work demonstrated that noble rot causes a major reprogramming of berry development and metabolism. This desirable interaction between a fruit and a fungus stimulates pathways otherwise inactive in white-skinned berries, leading to a greater accumulation of compounds involved in the unique flavor and aroma of botrytized wines.

  17. Comparing root architectural models

    Science.gov (United States)

    Schnepf, Andrea; Javaux, Mathieu; Vanderborght, Jan

    2017-04-01

    Plant roots play an important role in several soil processes (Gregory 2006). Root architecture development determines the sites in soil where roots provide input of carbon and energy and take up water and solutes. However, root architecture is difficult to determine experimentally when grown in opaque soil. Thus, root architectural models have been widely used and been further developed into functional-structural models that are able to simulate the fate of water and solutes in the soil-root system (Dunbabin et al. 2013). Still, a systematic comparison of the different root architectural models is missing. In this work, we focus on discrete root architecture models where roots are described by connected line segments. These models differ (a) in their model concepts, such as the description of distance between branches based on a prescribed distance (inter-nodal distance) or based on a prescribed time interval. Furthermore, these models differ (b) in the implementation of the same concept, such as the time step size, the spatial discretization along the root axes or the way stochasticity of parameters such as root growth direction, growth rate, branch spacing, branching angles are treated. Based on the example of two such different root models, the root growth module of R-SWMS and RootBox, we show the impact of these differences on simulated root architecture and aggregated information computed from this detailed simulation results, taking into account the stochastic nature of those models. References Dunbabin, V.M., Postma, J.A., Schnepf, A., Pagès, L., Javaux, M., Wu, L., Leitner, D., Chen, Y.L., Rengel, Z., Diggle, A.J. Modelling root-soil interactions using three-dimensional models of root growth, architecture and function (2013) Plant and Soil, 372 (1-2), pp. 93 - 124. Gregory (2006) Roots, rhizosphere and soil: the route to a better understanding of soil science? European Journal of Soil Science 57: 2-12.

  18. Some new and noteworthy diseases of poplars in India. [Botryodiplodia sett-rot; Alternaria tip blight; Cladosporium leaf spot; Fusarium pink incrustation

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.

    1983-09-01

    Four new diseases of poplars namely Botryodiplodia sett-rott, Alternaria tip blight, Cladosporium leaf spot and Fusarium pink incrustation are described in this paper. Botryodiplodia palmarum causes sett-rott of poplars both at pre-sprouting and post-sprouting stage. The pathogen also causes mortality of poplar plants in the field within 4-6 weeks after planting. Alternaria stage of Pleuspora infectoria has been found as the cause of blackening and dying of growing tips and young leaves of a Populus sp. and P. deltoides in nurseries. Cladosporium humile has been recorded as the cause of brown spot followed by crumpling and premature shedding of leaves in P. ciliata, P. nigra and P. alba. The cause of Fusarium incrustation disease on P. cilata has been identified as Fusarium sp. of Gibbosum group. Pathogenicity of Botryodiplodia palmarum and Alternaria stage of Pleospora infectoria was confirmed by artificial inoculations. Brief descriptions of Alternaria, Cladosporium and Fusarium are also given. The paper also gives a short account of some noteworthy diseases recorded on poplars namely Ganoderma root rot, foliage ruts and stem cankers. Ganoderma root-rot is found to reach alarming proportions in closely spaced poplar plantations. Melampsora ciliata, an indigenous rust, is found to attack mainly clones of P. deltoides, P. yunnanensis, P. trichocarpa, P. alba and some cultivars of P. x euramericana in nurseries. A brief account of three types of stem cankers i.e. cankers due to pink disease fungus, Corticium salmonicolor, sun-scaled cankers and cankers associated with slime flux on various clones of P. deltoides is also given.

  19. Comparative transcriptome profiling of the early infection of wheat roots by Gaeumannomyces graminis var. tritici.

    Directory of Open Access Journals (Sweden)

    Lirong Yang

    Full Text Available Take-all, which is caused by the fungal pathogen, Gaeumannomyces graminis var. tritici (Ggt, is an important soil-borne root rot disease of wheat occurring worldwide. However, the genetic basis of Ggt pathogenicity remains unclear. In this study, transcriptome sequencing for Ggt in axenic culture and Ggt-infected wheat roots was performed using Illumina paired-end sequencing. Approximately 2.62 and 7.76 Gb of clean reads were obtained, and 87% and 63% of the total reads were mapped to the Ggt genome for RNA extracted from Ggt in culture and infected roots, respectively. A total of 3,258 differentially expressed genes (DEGs were identified with 2,107 (65% being 2-fold up-regulated and 1,151 (35% being 2-fold down-regulated between Ggt in culture and Ggt in infected wheat roots. Annotation of these DEGs revealed that many were associated with possible Ggt pathogenicity factors, such as genes for guanine nucleotide-binding protein alpha-2 subunit, cellulase, pectinase, xylanase, glucosidase, aspartic protease and gentisate 1, 2-dioxygenase. Twelve DEGs were analyzed for expression by qRT-PCR, and could be generally divided into those with high expression only early in infection, only late in infection and those that gradually increasing expression over time as root rot developed. This indicates that these possible pathogenicity factors may play roles during different stages of the interaction, such as signaling, plant cell wall degradation and responses to plant defense compounds. This is the first study to compare the transcriptomes of Ggt growing saprophytically in axenic cultures to it growing parasitically in infected wheat roots. As a result, new candidate pathogenicity factors have been identified, which can be further examined by gene knock-outs and other methods to assess their true role in the ability of Ggt to infect roots.

  20. Comparative transcriptome profiling of the early infection of wheat roots by Gaeumannomyces graminis var. tritici.

    Science.gov (United States)

    Yang, Lirong; Xie, Lihua; Xue, Baoguo; Goodwin, Paul H; Quan, Xin; Zheng, Chuanlin; Liu, Taiguo; Lei, Zhensheng; Yang, Xiaojie; Chao, Yueen; Wu, Chao

    2015-01-01

    Take-all, which is caused by the fungal pathogen, Gaeumannomyces graminis var. tritici (Ggt), is an important soil-borne root rot disease of wheat occurring worldwide. However, the genetic basis of Ggt pathogenicity remains unclear. In this study, transcriptome sequencing for Ggt in axenic culture and Ggt-infected wheat roots was performed using Illumina paired-end sequencing. Approximately 2.62 and 7.76 Gb of clean reads were obtained, and 87% and 63% of the total reads were mapped to the Ggt genome for RNA extracted from Ggt in culture and infected roots, respectively. A total of 3,258 differentially expressed genes (DEGs) were identified with 2,107 (65%) being 2-fold up-regulated and 1,151 (35%) being 2-fold down-regulated between Ggt in culture and Ggt in infected wheat roots. Annotation of these DEGs revealed that many were associated with possible Ggt pathogenicity factors, such as genes for guanine nucleotide-binding protein alpha-2 subunit, cellulase, pectinase, xylanase, glucosidase, aspartic protease and gentisate 1, 2-dioxygenase. Twelve DEGs were analyzed for expression by qRT-PCR, and could be generally divided into those with high expression only early in infection, only late in infection and those that gradually increasing expression over time as root rot developed. This indicates that these possible pathogenicity factors may play roles during different stages of the interaction, such as signaling, plant cell wall degradation and responses to plant defense compounds. This is the first study to compare the transcriptomes of Ggt growing saprophytically in axenic cultures to it growing parasitically in infected wheat roots. As a result, new candidate pathogenicity factors have been identified, which can be further examined by gene knock-outs and other methods to assess their true role in the ability of Ggt to infect roots.

  1. Genetic analysis of partial resistance to basal stem rot (Sclerotinia sclerotiorum in sunflower

    Directory of Open Access Journals (Sweden)

    Amouzadeh Masoumeh

    2013-01-01

    Full Text Available Basal stem rot, caused by Sclerotinia sclerotiorum (Lib. de Bary, is one of the major diseases of sunflower (Helianthus annuus L. in the world. Quantitative trait loci (QTLs implicated in partial resistance to basal stem rot disease were identified using 99 recombinant inbred lines (RILs from the cross between sunflower parental lines PAC2 and RHA266. The study was undertaken in a completely randomized design with three replications under controlled conditions. The RILs and their parental lines were inoculated with a moderately aggressive isolate of S. sclerotiorum (SSKH41. Resistance to disease was evaluated by measuring the percentage of necrosis area three days after inoculation. QTLs were mapped using an updated high-density SSR and SNP linkage map. ANOVA showed significant differences among sunflower lines for resistance to basal stem rot (P≤0.05. The frequency distribution of lines for susceptibility to disease showed a continuous pattern. Composite interval mapping analysis revealed 5 QTLs for percentage of necrotic area, localized on linkage groups 1, 3, 8, 10 and 17. The sign of additive effect was positive in 5 QTLs, suggesting that the additive allele for partial resistance to basal stem rot came from the paternal line (RHA266. The phenotypic variance explained by QTLs (R2 ranged from 0.5 to 3.16%. Identified genes (HUCL02246_1, GST and POD, and SSR markers (ORS338, and SSL3 encompassing the QTLs for partial resistance to basal stem rot could be good candidates for marker assisted selection.

  2. Eco-friendly Rot and Crease Resistance Finishing of Jute Fabric using Citric Acid and Chitosan

    Science.gov (United States)

    Samanta, A. K.; Bagchi, A.

    2013-03-01

    Citric acid (CA) along with chitosan was used on bleached jute fabrics to impart anti crease and rot resistance properties in one step. The treatment was carried out by pad-dry-cure method in presence of sodium hypophosphite monohydrate catalyst. Curing at 150° Centigrade for 5 min delivered good crease resistant property (dry crease recovery angle is 244°) and high rot resistance simultaneously by a single treatment, which are durable for five washings with distilled water. Strength retention of jute fabric after 21 days soil burial was found to be 81 % and the loss (%) in strength due to this treatment was 15-18 %. The results showed that chitosan and CA treated-fabric exhibited higher rot resistance (as indicated by soil burial test) when compared to either CA or chitosan by individual treatment. The effect of CA and chitosan combination on the resistance to rotting of jute fabric was found to be synergistic which is higher than the sum of the effects of individual chemicals. CA possibly reacts with hydroxyl groups in cellulose or chitosan to form ester. The CA and chitosan finished fabric has adverse effect on stiffness. Thermal studies showed that final residue left at 500° C was much higher for CA and chitosan treated fabric than untreated jute fabric. FTIR spectroscopy suggested the formation of ester cross-linkage between the jute fibre, CA and chitosan and hence it is understood that this rot resistant finish on jute fabric become durable by this mechanism.

  3. Synthetic fertilization reduction with compost and irrigation optimization on maize stem rot (Fusarium spp

    Directory of Open Access Journals (Sweden)

    Blanca E. López Valenzuela

    2014-09-01

    Full Text Available Maize is the most important grain crop in Mexico due to the largest area grown and as the main source of feeding nationwide; being Sinaloa de major producer. The same crop over repeated seasons has favored disease proliferation of stem and ear rot mainly attributed to Fusarium spp which represents a risk potential so that growers are warned top pay close attention to crop management. With the purpose of evaluating the effect of synthetic fertilization with compost and irrigation on maize stem and ear rot at Valle del Fuerte. Field experiments were conducted in the growing season of 2009 at INIFAP. The experiments were arranged under a split plot in randomized complete block design with three replicates. At the end of the season, it was found that fertilization or irrigation by themselves did not have any significant effect in yield and phenology variables evaluated. However, incidence on stem rot which was evaluated at 53 days after planting was that of 100%. Moreover, there were significant differences regarding severity of rotten ears when less irrigation was applied. Finally, morphological study showed that the main agent associated in maize stem rot was Fusarium verticilliodes. In contrast to that of ear rot that the main agents involved were Apergillus spp, Penicillum pinophilum, and with a higher incidence was Fusarium verticilliodes.

  4. Involvement of phenolic compounds in the susceptibility of bananas to crown rot. A review

    Directory of Open Access Journals (Sweden)

    Lassois, L.

    2012-01-01

    Full Text Available Crown rot of bananas, caused by a fungal parasitic complex, is one of the main quality defects of exported bananas. Major variations in the susceptibility of bananas to crown rot have been observed in different production zones. The physiological state of the banana fruit at harvest is said to influence its response to pathogenic attack and thus to modulate its susceptibility to crown rot. The susceptibility of bananas to this disease, however, appears to be influenced by many pre-harvest factors, although the underlying defense mechanisms have not been clearly identified. A recent report based on molecular analyses suggests that phenolic compounds might be involved in the different variations in the susceptibility of bananas to crown rot. Results of other earlier studies point to an involvement of phenolic compounds in the defensive reactions of banana plants against various pathogens. The present paper reviews the current state of knowledge on the variations in the susceptibility of bananas to crown rot and takes stock of what is known about phenolic compounds in relation to their potential involvement in the defense mechanisms of the banana plant.

  5. Behavior of hybrid corn crop as second rot incidence in West Region Paraná

    Directory of Open Access Journals (Sweden)

    Jean Sérgio Rosset

    2013-09-01

    Full Text Available The objective of this study was to evaluate the incidence and influence of stalk rot and ear in cultivation of hybrid corn second crop in west region Paraná. The experiment was conducted in randomized block design with six transgenic corn hybrids (DKB 330PRO, P4285HX, P3646HX, 30F53HX, P3340HX and P3161HX with four replications at spacing of 0.90 m between rows and 0.20 m between plants. The characteristics evaluated were: number of healthy and symptomatic plants, number of ears healthy and symptomatic and total number of spikes. After harvest, we assessed the length of ears healthy and symptomatic, bulk grain ears healthy and symptomatic, thousand grain weight of ears healthy and symptomatic, and grain mass per spike weighted, thousand grain weight and weighted productivity. The hybrid P3646HX showed 100% of plants with stem base rot (Colletotrichum graminicola and soft rot cob (Erwinia chrysanthemi pv. Zeae and 100% of ears with symptoms of soft rot, followed by hybrid 30F53HX, DKB 330PRO with 34.9 and 29.1% of ears with symptoms of soft rot respectively. The hybrid DKB330PRO showed healthy spikes and patients with superior size, resulting in less interference in the grain yield. The hybrid P3340 productivity was higher, with 7952 kg ha-1 , followed by hybrid 30F53HX and DKB330PRO. A positive correlation between agronomic characteristics and grain yield.

  6. Investigation on Resistance against White-rot and Brown-rot Fungi of some Fire Retardant Chemicals in Laminate Flooring

    Directory of Open Access Journals (Sweden)

    Ferhat Özdemir

    2013-11-01

    Full Text Available The objective of this study is to determine the effects of some fire retardants on decay resistance of the high density fiberboard (HDF panels covered with overlay, decorative and balance papers. Borax (BX, boric acid (BA, ammonium polyphosphate (APP and alpha-x (AX as fire retardant (FR chemicals were added as powder into the fibers made from 50% pine and 50% beech woods at 3%, 6% and 9% levels based on oven-dry fiber weight. HDF panels (400x400x6.5mm were produced. After, surfaces of the panels were coated with overlay, decorative and balance papers. The panels were exposed to white (Ceriporiopsis subvermisphora and brown (Coniophora puteana decay fungi. The decay resistance of panels was investigated. The results showed that the addition of FR chemicals increased resistance against white and brown rot fungi of the panels. Thus, it was ascertained that concentration and type of FR chemicals are effective on decay resistance of laminate flooring

  7. The brown rot fungi of fruit crops (Monilinia spp.), with special reference to Monilinia fructigena (Aderh. & Ruhl.) Honey

    NARCIS (Netherlands)

    Leeuwen, van G.C.M.

    2000-01-01

    The brown rot fungi of fruit crops ( Monilinia spp.) cause blossom blight, twig blight, and fruit rot in rosaceous fruit crops in the temperate regions of the world. Three species are distinguished, of which M. fructicola and M. laxa

  8. Effect of wheel traffic and green manure treatments on forage yield and crown rot in alfalfa (Medicago sativa)

    Science.gov (United States)

    Harvesting alfalfa (Medicago sativa) results in mechanical wheel traffic on plants, which may damage crowns and increase the opportunity for entry of pathogens causing crown rot. Developing resistance to crown rot is problematic due to the large number of pathogens involved. Incorporation of plant b...

  9. Characterizing forest root‐ and butt‐rot fungi in Yap, Palau, Pohnpei, Kosrae, Guam and Saipan [Chapter III

    Science.gov (United States)

    Phil Cannon; Ned B. Klopfenstein; Mee-Sook Kim; Yuko Ota; Norio Sahashi; Robert L. Schlub; Roger Brown; Sara M. Ashiglar; Amy L. Ross-Davis; John W. Hanna

    2014-01-01

    Ganoderma and Phellinus are two common fungal genera causing butt-rot on trees growing on USA-affiliated islands of the western Pacific. Although these fungi can be quite prevalent, especially in some older mangrove stands, it appears that the majority of infections caused by these fungi leads to severe rotting of the heartwood but do not kill the living...

  10. New insights into the ecological interaction between grape berry microorganisms and Drosophila flies during the development of sour rot.

    Science.gov (United States)

    Barata, André; Santos, Sara Correia; Malfeito-Ferreira, Manuel; Loureiro, Virgílio

    2012-08-01

    In this work, we studied the ecological interactions between grape berry microorganisms and Drosophila sp. flies involved in sour rot disease during grape ripening. After veráison the total microbial counts of grape berries affected by sour rot increased from about 2 log CFU/g of berries to more than 7 log CFU/g. Berry damage provoked a clear shift in yeast diversity from basidiomycetes to ascomycetous fermentative species. The latter were mostly Pichia terricola, Hanseniaspora uvarum, Candida zemplinina, and Zygoascus hellenicus. However, these species were not able to produce the metabolites characteristic of sour rot (gluconic and acetic acids) in inoculated berries. On the contrary, the acetic acid bacteria Gluconacetobacter saccharivorans produced high levels of these acids, mainly when berries were incubated in the presence of the insect Drosophila sp. Sour rot was not observed when grape bunches were physically separated from insects, even when berries were artificially injured. The wounds made in berry skin healed in the absence of insects, thus preventing the development of sour rot. Therefore, in the vineyard, the induction of sour rot depends on the contamination of wounded berries by a microbial consortium--yeasts and acetic acid bacteria--transported by drosophilid insects which disseminate sour rot among damaged berries. In the absence of these insects, plant defense mechanisms are effective and lead to skin healing, preventing disease spread. Thus, we showed that Drosophila sp. act as a vector for microorganisms associated with grape sour rot disease.

  11. Chitosan and oligochitosan enhance ginger (Zingiber officinale Roscoe) resistance to rhizome rot caused by Fusarium oxysporum in storage

    Science.gov (United States)

    The ability of chitosan and oligochitosan to enhance the resistance of ginger (Zingiber officinale) to rhizome rot, caused by Fusarium oxysporum, in storage was investigated. Both chitosan and oligochitosan at 1 and 5 g/L significantly inhibited rhizome rot, relative to the untreated control, with...

  12. Multiplex detection and identification of bacterial pathogens causing potato blackleg and soft rot in Europe, using padlock probes

    NARCIS (Netherlands)

    Slawiak, M.; Doorn, van R.; Szemes, M.; Speksnijder, A.G.C.L.; Waleron, M.; Wolf, van der J.M.; Lojkowska, E.; Schoen, C.D.

    2013-01-01

    The objective of this study was to develop a multiplex detection and identification protocol for bacterial soft rot coliforms, namely Pectobacterium wasabiae (Pw), Pectobacterium atrosepticum (Pba) and Dickeya spp., responsible for potato blackleg and tuber soft rot. The procedures were derived from

  13. Mucor rot - An emerging postharvest disease of mandarin fruit caused by Mucor piriformis and other Mucor spp. in California

    Science.gov (United States)

    In recent years, an emerging, undescribed postharvest fruit rot disease was observed on mandarin fruit after extended storage in California. We collected decayed mandarin fruit from three citrus packinghouses in the Central Valley of California in 2015 and identified this disease as Mucor rot caused...

  14. Formation of dry gram-negative bacteria biocontrol products and small pilot tests against potato dry rot

    Science.gov (United States)

    Pseudomonas fluorescens strains S11:P:12, P22:Y:05, and S22:T:04 reduce important potato maladies in storage including dry rot, late blight, pink rot, and sprouting. Experiments were conducted to identify methods for producing a dried, efficacious biological control product from one or more of these...

  15. The brown rot fungi of fruit crops (Monilinia spp.), with special reference to Monilinia fructigena (Aderh. & Ruhl.) Honey

    NARCIS (Netherlands)

    Leeuwen, van G.C.M.

    2000-01-01

    The brown rot fungi of fruit crops ( Monilinia spp.) cause blossom blight, twig blight, and fruit rot in rosaceous fruit crops in the temperate regions of the world. Three species are distinguished, of which M. fructicola and M.

  16. Use of plant growth-promoting rhizobacteria (PGPR and soil organic amendments for the management of root diseases complex of uridbean

    Directory of Open Access Journals (Sweden)

    I. A. Siddiqui

    2013-12-01

    Full Text Available Efficacy of two strains of Pseudomonas aeruginosa (Pa-5 and IE-2 and Bacillus subtilis isolate alone or in conjunction with neem cake or Datura fastuosa was tested for the management of three soilbrne root-infecting fungi including Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani and the root-knot nematode, Meloidogyne javanica on uridbean. Biocontrol bacteria used in combination with either neem cake or D.fastuosa gave better control of the root-rot and root-knot infection with the enhancement of growth of uridbean compared to the use ofeither component alone. Neem cake l% w/w mixed with P.aeruginosa strain IE-2 caused greatest inhibition of the root-knot development due to M.javanica, P.aeruginosa and B.subtilis used with organic amendment also increased Bradyrhizobium-nodules in the root system.

  17. The Root Pressure Phenomenon

    Science.gov (United States)

    Marsh, A. R.

    1972-01-01

    Describes experiments demonstrating that root pressure in plants is probably controlled by a circadian rhythm (biological clock). Root pressure phenomenon plays significant part in water transport in contradiction with prevalent belief. (PS)

  18. Serpula lacrymans, The Dry Rot Fungus and Tolerance Towards Copper-Based Wood Preservatives

    DEFF Research Database (Denmark)

    Hastrup, Anne Christine Steenkjær; Jensen, Bo; Clausen, Carol;

    2005-01-01

    wood preservatives were the most commonly used preservatives for pressure treatment of wood for building constructions. Because of a suspicion about tolerance toward copper components, a soil block test was undertaken to clarify the effect of two copper based preservatives, copper citrate and ACQ......Serpula lacrymans (Wulfen : Fries) Schröter, the dry rot fungus, is considered the most (Wulfen : Fries) Schröterthe dry rot fungus, is considered the most economically important wood decay fungus in temperate regions of the world i.e. northern Europe, Japan and Australia. Previously copper based......-D, on the dry rot fungus, Serpula lacrymans compared to an alternative non-copper containing wood preservative. The extensive use of copper-based wood preservatives has hastened the need for understanding why some fungi are able to attack copper-treated wood. The copper tolerance of S. lacrymans and other brown...

  19. Effect of Chitosan on Rhizome Rot Disease of Turmeric Caused by Pythium aphanidermatum.

    Science.gov (United States)

    Anusuya, Sathiyanarayanan; Sathiyabama, Muthukrishnan

    2014-01-01

    Chitosan was evaluated for its potential to induce antifungal hydrolases in susceptible turmeric plant (Curcuma longa L.). Under field conditions, the application of chitosan (crab shell) to turmeric plants by foliar spray method induces defense enzymes such as chitinases and chitosanases. Such an increase in enzyme activity was enhanced by spraying chitosan (0.1% w/v) on leaves of turmeric plants at regular intervals. Gel electrophoresis revealed new chitinase and chitosanase isoforms in leaves of turmeric plants treated with chitosan. Treated turmeric plants showed increased resistance towards rhizome rot disease caused by Pythium aphanidermatum, whereas control plants expressed severe rhizome rot disease. Increased activity of defense enzymes in leaves of chitosan treated turmeric plants may play a role in restricting the development of disease symptoms. The eliciting properties of chitosan make chitosan a potential antifungal agent for the control of rhizome rot disease of turmeric.

  20. The Chaperone ClpX Stimulates Expression of Staphylococcus aureus Protein A by Rot Dependent and Independent Pathways

    DEFF Research Database (Denmark)

    Jelsbak, Lotte; Ingmer, Hanne; Valihrach, Lukás;

    2010-01-01

    The Clp ATPases (Hsp100) constitute a family of closely related proteins that have protein reactivating and remodelling activities typical of molecular chaperones. In Staphylococcus aureus the ClpX chaperone is essential for virulence and for transcription of spa encoding Protein A. The present...... study was undertaken to elucidate the mechanism by which ClpX stimulates expression of Protein A. For this purpose, we prepared antibodies directed against Rot, an activator of spa transcription, and demonstrated that cells devoid of ClpX contain three-fold less Rot than wild-type cells. By varying Rot...... expression from an inducible promoter we showed that expression of Protein A requires a threshold level of Rot. In the absence of ClpX the Rot content is reduced below this threshold level, hence, explaining the substantially reduced Protein A expression in the clpX mutant. Experiments addressed...

  1. ISOLATION AND IDENTIFICATION OF BACTERIAL CAUSED SOFT ROT DISEASE ON CARROT (Daucus carota L. LOCAL VARIETY IN BALI

    Directory of Open Access Journals (Sweden)

    Ni Wayan Desi Bintari

    2015-03-01

    Full Text Available Soft rot bacteria infection in carrot tuber (D. carota L. causes severe economic losses. Soft rot disease can be caused by various bacteria belonging to Enterobacteriaceae. This study aimed to isolate and identify bacteria as causal agent of soft rot disease in local carrot variety in Bali. Samples were collected at Badung Tradisional Market, Denpasar, Bali. Isolation was carried out by serial dilution method (Platting Method. Eight bacteria (BL1, BL2, BL3, BL4, BL5, BL6, BL7 and BL8 were isolated from soft rot tuber. BL6 isolate showed positive result in Postulat Koch test that caused soft rot on carrot tuber. The result of identification by Microgen™ GnA+B-ID System and identification book Bergeys’s Manual of Determinative Bacteriology Ninth Edition (Holt et al., 1994, BL6 was identified as Citrobacter.

  2. The Root Canal Biofilm

    NARCIS (Netherlands)

    Sluis, van der L.W.M.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, M.; Chávez de Paz, E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  3. WHY ROOTING FAILS.

    Energy Technology Data Exchange (ETDEWEB)

    CREUTZ,M.

    2007-07-30

    I explore the origins of the unphysical predictions from rooted staggered fermion algorithms. Before rooting, the exact chiral symmetry of staggered fermions is a flavored symmetry among the four 'tastes.' The rooting procedure averages over tastes of different chiralities. This averaging forbids the appearance of the correct 't Hooft vertex for the target theory.

  4. Root canal irrigation

    NARCIS (Netherlands)

    L. van der Sluis; C. Boutsioukis; L.M. Jiang; R. Macedo; B. Verhaagen; M. Versluis

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  5. Rooting gene trees without outgroups: EP rooting.

    Science.gov (United States)

    Sinsheimer, Janet S; Little, Roderick J A; Lake, James A

    2012-01-01

    Gene sequences are routinely used to determine the topologies of unrooted phylogenetic trees, but many of the most important questions in evolution require knowing both the topologies and the roots of trees. However, general algorithms for calculating rooted trees from gene and genomic sequences in the absence of gene paralogs are few. Using the principles of evolutionary parsimony (EP) (Lake JA. 1987a. A rate-independent technique for analysis of nucleic acid sequences: evolutionary parsimony. Mol Biol Evol. 4:167-181) and its extensions (Cavender, J. 1989. Mechanized derivation of linear invariants. Mol Biol Evol. 6:301-316; Nguyen T, Speed TP. 1992. A derivation of all linear invariants for a nonbalanced transversion model. J Mol Evol. 35:60-76), we explicitly enumerate all linear invariants that solely contain rooting information and derive algorithms for rooting gene trees directly from gene and genomic sequences. These new EP linear rooting invariants allow one to determine rooted trees, even in the complete absence of outgroups and gene paralogs. EP rooting invariants are explicitly derived for three taxon trees, and rules for their extension to four or more taxa are provided. The method is demonstrated using 18S ribosomal DNA to illustrate how the new animal phylogeny (Aguinaldo AMA et al. 1997. Evidence for a clade of nematodes, arthropods, and other moulting animals. Nature 387:489-493; Lake JA. 1990. Origin of the metazoa. Proc Natl Acad Sci USA 87:763-766) may be rooted directly from sequences, even when they are short and paralogs are unavailable. These results are consistent with the current root (Philippe H et al. 2011. Acoelomorph flatworms are deuterostomes related to Xenoturbella. Nature 470:255-260).

  6. Greenhouse evaluation of rhizobia as biocontrol agent of root-infecting fungi in okra

    Directory of Open Access Journals (Sweden)

    I. A. Siddiqui

    2013-12-01

    Full Text Available Nine rhizobial strains isolated from the root nodules of Cicer arietinum, Vigna radiata, V. mungo, Samania saman, Sesbania sesban, Leucinia sp., Prosopis cineraria and Medicago sativa were used to study their effects on root-infecting fungi viz., Macrophomina phaseolina, Fusarium solani and Rhizoctonia solani. In dual culture plate assay, strains of Bradyrhizobium sp., and R. meliloti were found to inhibit radial growth of M. phaseolina, F. solani and R. solani producing zones of inhibition. Bradyrhizobium sp., and R. meliloti either used as seed dressing or as soil drench significantly suppressed root-rot infection caused by M. phaseolina, F. solani and R. solani in okra, a non-1eguminous crop under greenhouse conditions. Biomass of plants was also higher in the presence of rhizobia.

  7. Role of rhizobitoxine in protecting soybean roots from Macrophomina phaseolina infection.

    Science.gov (United States)

    Chakraborty, U; Purkayastha, R P

    1984-03-01

    Bacterization of soybean seeds or roots with Rhizobium japonicum significantly reduced charcoal rot disease caused by Macrophomina phaseolina . Rhizobium japonicum inhibited the growth of M. phaseolina on both liquid and solid media. Replacement of nutrient medium with culture filtrate of R. japonicum significantly reduced mycelial growth of M. phaseolina . Whole culture extracts of R. japonicum yielded a toxic substance which was identified as rhizobitoxine after chromatographic, ultraviolet, and infrared spectrophotometric analyses. This compound also was detected in the roots of soybean inoculated with either R. japonicum alone or in combination of R. japonicum and M. phaseolina . Dosage response curves with rhizobitoxine showed it to be antifungal. The possible role of rhizobitoxine in protecting soybean roots from M. phaseolina infection is discussed.

  8. Extracellular DNA is required for root tip resistance to fungal infection.

    Science.gov (United States)

    Wen, Fushi; White, Gerard J; VanEtten, Hans D; Xiong, Zhongguo; Hawes, Martha C

    2009-10-01

    Plant defense involves a complex array of biochemical interactions, many of which occur in the extracellular environment. The apical 1- to 2-mm root tip housing apical and root cap meristems is resistant to infection by most pathogens, so growth and gravity sensing often proceed normally even when other sites on the root are invaded. The mechanism of this resistance is unknown but appears to involve a mucilaginous matrix or "slime" composed of proteins, polysaccharides, and detached living cells called "border cells." Here, we report that extracellular DNA (exDNA) is a component of root cap slime and that exDNA degradation during inoculation by a fungal pathogen results in loss of root tip resistance to infection. Most root tips (>95%) escape infection even when immersed in inoculum from the root-rotting pathogen Nectria haematococca. By contrast, 100% of inoculated root tips treated with DNase I developed necrosis. Treatment with BAL31, an exonuclease that digests DNA more slowly than DNase I, also resulted in increased root tip infection, but the onset of infection was delayed. Control root tips or fungal spores treated with nuclease alone exhibited normal morphology and growth. Pea (Pisum sativum) root tips incubated with [(32)P]dCTP during a 1-h period when no cell death occurs yielded root cap slime containing (32)P-labeled exDNA. Our results suggest that exDNA is a previously unrecognized component of plant defense, an observation that is in accordance with the recent discovery that exDNA from white blood cells plays a key role in the vertebrate immune response against microbial pathogens.

  9. Biocontrol Characteristics of Bacillus Species in Suppressing Stem Rot of Grafted Cactus Caused by Bipolaris cactivora

    OpenAIRE

    Sooil Bae; Sang Gyu Kim; Young Ho Kim

    2013-01-01

    One of the most important limiting factors for the production of the grafted cactus in Korea is the qualitative and quantitative yield loss derived from stem rots especially caused by Bipolaris cactivora. This study is aimed to develop microbial control agents useful for the control of the bipolaris stem rot. Two bacteria (GA1-23 and GA4-4) selected out of 943 microbial isolates because of their strong antibiotic activity against B. cactivora were identified as Bacillus subtilis and B. amylol...

  10. The Three-Arm Michelson-Fabry-Pérot Detector for Gravitational Waves

    Institute of Scientific and Technical Information of China (English)

    Chao-Guang Huang; Yong-Gui Li; Ning Zhu

    2016-01-01

    A three-arm Michelson-Fabry-Pérot detector for gravitational waves is designed.It consists of three Michelson Fabry-Pérot interferometers,one for each pair of arms.The new detector can be used to confirm whether the gravitational waves are in general relativity polarization states and to set the strong constraints on non-GR gravitational wave polarization states.By the new detectors,the angular resolution of sources can be improved significantly.With the new detector,it is easier to search for and confirm a gravitational wave signal in the observation data.

  11. Model of Fabry-Pérot-type electromagnetic modes of a cylindrical nanowire

    DEFF Research Database (Denmark)

    Bordo, Vladimir

    2010-01-01

    The rigorous theory of normal electromagnetic modes of a cylindrical nanowire of finite length is developed. The exact integral equation which determines the solution of Maxwell's equations obeying the boundary conditions at the whole nanowire surface is derived. The nanowire normal (Fabry......-Pérot) modes are defined as non-trivial solutions of the source-free equation. The approach is considered in more detail for elongated nanowires whose length is much larger than their diameter. The resonance condition obtained for a single-mode nanowire resembles the formula for the Fabry-Pérot resonator...

  12. Functional Genomics of Lignocellulose Degradation in the Basidiomycete White Rot Schizophyllum commune

    Energy Technology Data Exchange (ETDEWEB)

    Ohm, Robin A. [Joint Genome Inst., Walnut Creek, CA (United States); Tegelaar, Martin [Utrecht Univ. (Netherlands); Henrissat, Bernard [Univ. of Marseille (France); Brewer, Heather M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Purvine, Samuel O. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baker, Scott [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wosten, Han A. B. [Utrecht Univ. (Netherlands); Grigoriev, Igor V. [Joint Genome Inst., Walnut Creek, CA (United States); Lugones, Luis G. [Utrecht Univ. (Netherlands)

    2013-03-01

    White and brown rot fungi are among the most important wood decayers in nature. Although more than 50 genomes of Basidiomycete white and brown rots have been sequenced by the Joint Genome Institute, there is still a lot to learn about how these fungi degrade the tough polymers present in wood. In particular, very little is known about how these fungi regulate the expression of genes involved in lignocellulose degradation. Here, we used transcriptomics, proteomics, and promoter analysis in an effort to gain insight into the process of lignocellulose degradation.

  13. Host Specialization in the Charcoal Rot Fungus, Macrophomina phaseolina.

    Science.gov (United States)

    Su, G; Suh, S O; Schneider, R W; Russin, J S

    2001-02-01

    ABSTRACT To investigate host specialization in Macrophomina phaseolina, the fungus was isolated from soybean, corn, sorghum, and cotton root tissue and soil from fields cropped continuously to these species for 15 years in St. Joseph, LA. Chlorate phenotype of each isolate was determined after growing on a minimal medium containing 120 mM potassium chlorate. Consistent differences in chlorate sensitivity were detected among isolates from different hosts and from soil versus root. To further explore genetic differentiation among fungal isolates from each host, these isolates were examined by restriction fragment length polymorphism and random amplified polymorphic DNA (RAPD) analysis. No variations were observed among isolates in restriction patterns of DNA fragments amplified by polymerase chain reaction covering the internal transcribed spacer region, 5.8S rRNA and part of 25S rRNA, suggesting that M. phaseolina constitutes a single species. Ten random primers were used to amplify the total DNA of 45 isolates, and banding patterns resulting from RAPD analysis were compared with the neighbor-joining method. Isolates from a given host were genetically similar to each other but distinctly different from those from other hosts. Chlorate-sensitive isolates were distinct from chlorate-resistant isolates within a given host. In greenhouse tests, soybean, sorghum, corn, and cotton were grown separately in soil infested with individual isolates of M. phaseolina that were chosen based on their host of origin and chlorate phenotype. Root colonization and plant weight were measured after harvesting. More colonization of corn roots occurred when corn was grown in soil containing corn isolates compared with isolates from other hosts. However, there was no host specialization in isolates from soybean, sorghum, or cotton. More root colonization in soybean occurred with chlorate-sensitive than with chlorate-resistant isolates.

  14. Decolorization of reactive brilliant red K-2BP by white rot fungus under sterile and non-sterile conditions

    Institute of Scientific and Technical Information of China (English)

    GAO Da-wen; WEN Xiang-hua; QIAN Yi

    2006-01-01

    Almost all the studies both domestic and international using white rot fungus for dye wastewater treatment are performed under sterile conditions. However, it is obviously unpractical that wastewater with dyes is treated under sterile conditions. A feasible study was made for using white rot fungus Phanerochaete chrysosporium to degrade reactive brilliant red K-2BP dye under non-sterile conditions. The results showed that there was no decolorizing effect under non-sterile condition if white rot fungus was incubated under non-sterile condition, and the decolorization was always near to 0% during decolorizing test for 3 d; in the meantime, a lot of yeast funguses were found in liquid medium when white rot fungus was incubated under non-sterile conditions; however, if white rot fungus was incubated under sterile condition firstly, its decolorization was above 90% under non-sterile condition, which was similar to that of sterile condition. So we point out that the treating process for wastewater with dyes should be divided into two stages. The first stage is that white rot fungus should be incubated under sterile conditions, and the second stage is that reactive brilliant red K-2BP is decolorized under non-sterile conditions. The method not only save the operation cost which decolorizing reactive brilliant red K-2BP under sterile condition, but also provide the feasibility for using white rot fungus to degrade wastewater with dyes under non-sterile conditions.

  15. Biological pretreatment of corn stover with white-rot fungus for improved enzymatic hydrolysis

    Science.gov (United States)

    Biological pretreatment of lignocellulosic biomass by white-rot fungus can represent a low-cost and eco-friendly alternative to harsh physical, chemical or physico-chemical pretreatment methods to facilitate enzymatic hydrolysis. However, fungal pretreatment can cause carbohydrate loss and it is, th...

  16. Biocontrol with Trichoderma species for the management of postharvest crown rot of banana

    Directory of Open Access Journals (Sweden)

    G. Sangeetha

    2009-09-01

    Full Text Available Lasiodiplodia theobromae and Colletotrichum musae cause the postharvest crown rot disease complex of banana. In vitro experiments evaluated the effect of twelve isolates of Trichoderma spp. from the soil of organic banana orchards (‘native isolates’ and eight isolates of Trichoderma spp. from culture collections (‘introduced isolates’ on the two pathogens. The native and introduced Trichoderma spp. had varied antagonistic effects against the two pathogens. Eight Trichoderma spp. isolates effective in the in vitro assays were evaluated singly on fruits both at room temperature and in cold storage. Single antagonists did not satisfactorily control crown rot on the fruits as compared with the fungicide carbendazim. However, two isolates of T. viride, one of T. harzianum and one of T. koningii performed well when applied singly, and these were selected for evaluation in isolate mixtures. There was very little antagonism between these isolates. Of 11 two-way, three-way and four-way mixtures of these isolates, the four-way and a three-way mixtures reduced crown rot incidence, both at room temperature and in cold storage, giving better control than carbendazim. The study identified consortia of compatible Trichoderma antagonists with superior biocontrol potential for the management of the postharvest crown rot complex of banana.

  17. CONTROL OF POSTHARVEST TOMATO ROT BY SPORE SUSPENSION AND ANTIFUNGAL METABOLITES OF TRICHODERMA HARZIANUM

    Directory of Open Access Journals (Sweden)

    Momein H. El-Katatny

    2012-06-01

    Full Text Available Rot of cherry tomato (Lycopersicon esculentum fruits caused by several fungal pathogens is a detrimental disease leading to substantial yield loses worldwide. Alternaria isolates were the most common fungal species isolated from healthy or rotten fruits. Trichoderma harzianum spore suspension and culture filtrate were tested for their antagonistic activity on controlling tomato fruit rot. T. harzianum isolates suppressed or interfered with the growth of different postharvest tomato fungal pathogens albeit at different degrees. Their culture filtrate inhibited pathogen spore germination possibly due to the released extracellular diffusible metabolite(s. Besides, aberrant morphology of conidia was observed with deformation of hyphal tips. Furthermore, the resulting mycelia appeared desiccated with coagulated protoplasm leading to complete collapse of protoplasm in presence of T. harzianum culture filtrate. Application of T. harzianum spores to tomato fruits decreased disease severity significantly with the most profound effect at higher spore concentrations (108 cells per ml. Similarly, culture filtrate of T. harzianum prevented pathogen spore germination on the surface of tomato fruits leading to decreased incidence of rot symptoms at high culture filtrate concentrations. This work provides strong evidence that T. harzianum is a competent antagonist and its spore suspension and culture filtrate can be used efficiently to control postharvest tomato rot.

  18. First report of truncatella angustata causing postharvest rot on ‘topaz’ apples in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Pham, K.T.K.; Boekhoudt, L.C.; Boer, de F.A.; Leeuwen, van P.J.; Hollinger, T.C.; Thomma, B.P.H.J.

    2017-01-01

    In the Netherlands, about 30% of the organic apple (Malus domestica Borkh.) production consists of apple scab resistant cultivars, such as Topaz and Santana. However, organic ‘Topaz’ apples show a high incidence of fungal rot after storage. Hot-water treatment (HWT) of freshly harvested apple fru

  19. Podridão do pimentão Black rot of green pepper fruits

    Directory of Open Access Journals (Sweden)

    A. P. Viégas

    1962-01-01

    Full Text Available Podridão do pimentão ainda verde, causada por Diaporthe phaseolorum, foi observada no Brasil, ao que parece, pela primeira vez.Black rot green fruits of Capsicum annuum L. caused by Diaporthe phaseolorum is reported for Brasil for the first time.

  20. Stenotrophomonas maltophilia: a new potential biocontrol agent of Ralstonia solanacearum, causal agent of potato brown rot

    NARCIS (Netherlands)

    Messiha, N.A.S.; Diepeningen, van A.D.; Farag, N.S.; Abdallah, S.A.; Janse, J.D.; Bruggen, van A.H.C.

    2007-01-01

    Stenotrophomonas maltophilia was isolated from the rhizosphere of eggplant in the Nile Delta of Egypt, and its antagonistic potential against Ralstonia solanacearum race 3 biovar 2, the causal agent of potato brown rot, was in vitro evaluated on KB agar medium and in vivo on potato plants. In vitro,

  1. Potato brown rot incidence and severity under different management and amendment regimes in different soil types

    NARCIS (Netherlands)

    Messiha, N.A.S.; Bruggen, van A.H.C.; Diepeningen, van A.D.; Vos, de O.J.; Termorshuizen, A.J.; Tjou-Tam-Sin, N.N.A.; Janse, J.D.

    2007-01-01

    Ralstonia solanacearum race 3 biovar 2, the causative agent of potato brown rot (bacterial wilt), is an economically important disease in tropical, subtropical and temperate regions of the world. In view of previous reports on suppression of the disease by organic amendments, and the expansion of or

  2. Host resistance to phytophthora fruit rot in U.S. watermelon plant introductions

    Science.gov (United States)

    Phytophthora capsici, distributed worldwide, is an aggressive pathogen with a broad host range, infecting solanaceous, leguminaceous, and cucurbitaceous crops. Phytophthora fruit rot of watermelon (Citrullus lanatus) caused by P. capsici was first reported in the U.S. in 1940. Since then, the dise...

  3. Genetic Architecture of Charcoal Rot (Macrophomina phaseolina) Resistance in Soybean Revealed Using a Diverse Panel

    Science.gov (United States)

    Charcoal rot disease caused by Macrophomina phaseolina is responsible for significant yield losses in soybean production. Among the methodologies available for controlling this disease, breeding for resistance is the most promising. Progress in breeding efforts has been slow due to the insufficient ...

  4. Evaluation of watermelon varieties for tolerance to powdery mildew and Phytophthora fruit rot, 2014

    Science.gov (United States)

    This experiment was conducted at the U.S. Vegetable Laboratory farm in Charleston, SC. The soil was Yonges loamy fine sand. This study was undertaken to determine the performance of seeded and seedless commercial watermelon varieties for tolerance to powdery mildew (PM) and Phytophthora fruit rot as...

  5. First report of truncatella angustata causing postharvest rot on ‘topaz’ apples in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Pham, K.T.K.; Boekhoudt, L.C.; Boer, de F.A.; Leeuwen, van P.J.; Hollinger, T.C.; Thomma, B.P.H.J.

    2017-01-01

    In the Netherlands, about 30% of the organic apple (Malus domestica Borkh.) production consists of apple scab resistant cultivars, such as Topaz and Santana. However, organic ‘Topaz’ apples show a high incidence of fungal rot after storage. Hot-water treatment (HWT) of freshly harvested apple

  6. Fruit age and development of Phytophthora fruit rot on resistant and susceptible watermelon lines

    Science.gov (United States)

    Phytophthora fruit rot caused by Phytophthora capsici is an emerging disease in most watermelon producing regions of Southeast U.S. and has resulted in severe losses to watermelon growers especially in GA, SC, and NC. We recently released four germplasm lines (USVL203-PFR, USVL020-PFR, USVL782-PFR,...

  7. Seasonal progress of charcoal rot and its impact on soybean productivity

    Science.gov (United States)

    The effects of charcoal rot caused by Macrophomina phaseolina on yield of soybean were evaluated in the field using two genotypes each in maturity groups III and IV. Four separate experiments were established in an area of a field fumigated with methyl bromide. The experiments were: 1) artificiall...

  8. POTATO RING ROT PATHOGEN DETECTION BY POLYMERASE CHAIN REACTION IN POTATO TUBERS

    Directory of Open Access Journals (Sweden)

    Shafikova T.N.

    2008-10-01

    Full Text Available Bacterial ring rot caused by Clavibacter michiganensis ssp. sepedonicus is a widespread disease of potato resulting in significant economic lost in agriculture and seed growing. A latent form of this infection makes difficulties for diagnostics and facilitates the quick disease propagation. Polymerase chain reaction is the best method for the disease control.

  9. Seed rot and damping-off of alfalfa in Minnesota caused by Pythium and Fusarium species

    Science.gov (United States)

    Globally, 15 Pythium species have been found to cause damping-off and seed rot of alfalfa, although surveys of species causing disease on alfalfa in the Midwestern U.S. are lacking. Pathogens were isolated by a seedling baiting technique from soil of five alfalfa fields in Minnesota with high levels...

  10. Processive endoglucanase active in crystalline cellulose hydrolysis by the brown rot Basidiomycete Gloeophyllum trabeum

    Science.gov (United States)

    Roni Cohen; Melissa R. Suzuki; Kenneth E. Hammel

    2005-01-01

    Brown rot basidiomycetes have long been thought to lack the processive cellulases that release soluble sugars from crystalline cellulose. On the other hand, these fungi remove all of the cellulose, both crystalline and amorphous, from wood when they degrade it. To resolve this discrepancy, we grew Gloeophyllum trabeum on microcrystalline cellulose (Avicel) and purified...

  11. Improving ruminal degradability of oil palm fronds using white rot fungi

    NARCIS (Netherlands)

    Rahman, M.M.; Lourenco, M.; Hassim, H.A.; Baars, J.J.P.; Sonnenberg, A.S.M.; Cone, J.W.; Boever, de J.L.; Fievez, V.

    2011-01-01

    The use of oil palm fronds (OPF) in livestock production is limited as up to 0.20 of their dry biomass is lignin. White rot fungi (WRF) are very effective basidiomycetes for biological pre-treatment as they degrade lignin extensively. Ten WRF were screened for their potential to increase OPF digesti

  12. A postharvest fruit rot of apple caused by Lambertella sp. in Washington state

    Science.gov (United States)

    During surveys for postharvest diseases of apples in 2003-05, a fruit rot disease was observed on stored apples collected from packinghouses. The disease appeared to originate from infections of wounds on the fruit, and lesions were brown and decayed tissues were spongy. Lambertella sp. was consiste...

  13. Indirect selection for resistance to ear rot and leaf diseases in maize lines using biplots.

    Science.gov (United States)

    Pereira, G S; Camargos, R B; Balestre, M; Von Pinho, R G; C Melo, W M

    2015-09-21

    Leaf disease and ear rot have caused reductions in maize yield in Brazil and other producer countries. Therefore, the aims of this study were to analyze the association between husked ear yield and the severity of maize white spot, gray leaf spot, helminthosporium, and ear rot caused by Fusarium verticillioides and Diplodia maydis using biplots in a mixed-model approach. The responses of 238 lines introduced to Brazil and four controls were evaluated using an incomplete block design with three replicates in two locations: Lavras and Uberlândia, Minas Gerais, Brazil. Two experiments were conducted in each location, one with F. verticillioides and the other with D. maydis. The mixed models elucidated the relationship between yield, leaf disease, and ear disease. Significant genotype x environment and genotype x pathogen interactions were observed. In conclusion, husked ear yield is more associated with ear rot than with the leaf diseases evaluated, justifying the indirect selection for resistance to kernel rot in maize-F. verticillioides and maize-D. maydis pathosystems by yield evaluation.

  14. Foliar application of β-D-glucan nanoparticles to control rhizome rot disease of turmeric.

    Science.gov (United States)

    Anusuya, Sathiyanarayanan; Sathiyabama, Muthukrishnan

    2015-01-01

    The soilborne Oomycete Pythium aphanidermatum is the causal agent of rhizome rot disease, one of the most serious threats to turmeric crops. At present, effective fungicides are not available. Researches on nanoparticles in a number of crops have evidenced the positive changes in gene expression indicating their potential use in crop improvement. Hence, experiments were carried out to determine the effect of β-D-glucan nanoparticles (nanobiopolymer) in protection of turmeric plants against rot disease by the way of products that reinforce plant's own defense mechanism. Foliar spray of β-D-glucan nanoparticles (0.1%, w/v) elicited marked increase in the activity of defense enzymes such as peroxidases (E.C.1.11.1.7), polyphenol oxidases (E.C.1.14.18.1), protease inhibitors (E.C.3.4.21.1) and β-1,3-glucanases (E.C.3.2.1.39) at various age levels. Constitutive and induced isoforms of these enzymes were investigated during this time-course study. β-D-glucan nanoparticles (GNPs) significantly reduced the rot incidence offering 77% protection. Increased activities of defense enzymes in GNPs-applied turmeric plants may play a role in restricting the development of disease symptoms. These results demonstrated that GNPs could be used as an effective resistance activator in turmeric for control of rhizome rot disease.

  15. Diversity and biological control of Sclerotium rolfsii, causal agent of stem rot of groundnut

    NARCIS (Netherlands)

    Lê, N.C.

    2011-01-01

    Groundnut (Arachis hypogaea L.) is an economically important legume crop in Vietnam and many other countries worldwide. Stem rot disease, caused by the soil-borne fungus Sclerotium rolfsii Sacc., is a major yield limiting factor in groundnut cultivation. Current control methods

  16. Diallel analysis of resistance to fusarium ear rot and fumonisin contamination in maize

    Science.gov (United States)

    The fungus Fusarium verticillioides infects maize ears and kernels, resulting in Fusarium ear rot disease, reduced grain yields, and contamination of grain with the mycotoxin fumonisin. Typical hybrid maize breeding programs involve selection for both favorable inbred and hybrid performance, and the...

  17. Loop-mediated isothermal amplification (LAMP) based detection of Colletotrichum falcatum causing red rot in sugarcane

    Science.gov (United States)

    Red rot, caused by Colletotrichum falcatum, is a destructive disease prevalent in most sugarcane-producing countries. Disease-free sugarcane planting materials are essential as the pathogen spreads primarily through infected setts. The present study was undertaken to develop loop-mediated isothermal...

  18. Modification of wheat straw lignin by solid state fermentation with white-rot fungi

    NARCIS (Netherlands)

    Dinis, M.J.; Bezerra, R.M.F.; Nunes, F.; Dias, A.A.; Guedes, C.; Ferreira, L.M.M.; Cone, J.W.; Marques, G.S.M.; Barros, A.R.N.; Rodrigues, M.A.M.

    2009-01-01

    The potential of crude enzyme extracts, obtained from solid state cultivation of four white-rot fungi (Trametes versicolor, Bjerkandera adusta, Ganoderma applanatum and Phlebia rufa), was exploited to modify wheat straw cell wall. At different fermentation times, manganese-dependent peroxidase (MnP)

  19. Chemical and biological control of Sclerotinia stem rot in the soybean crop

    Directory of Open Access Journals (Sweden)

    Ciro Hideki Sumida

    2015-05-01

    Full Text Available It was evaluated the effect of fungicides and the microbial control agent Trichoderma harzianum on the inhibition of the carpogenic and ascospore germination of Sclerotinia sclerotiorum. This study also evaluated the chemical, fungicidal and microbial control of white mold or Sclerotinia stem rot of soybean in the field. Three experiments were conducted, as follows: 1 inhibition of carpogenic germination of sclerotia, 2 inhibition of ascospore germination, and 3 control of Sclerotinia stem rot in a soybean crop under field conditions. The treatments evaluated were fluazinam, procymidone, iprodione, thiophanate-methyl, carbendazim, benzalkonium chloride + fluazinam, and T. harzianum. Procymidone resulted in an inhibition of 13.5% and benzalkonium chloride in an inhibition of 13.9% in an ascospore germination test. Fluazinam and procymidone were the most effective in reducing the production of ascospores/apothecium, representing 65.6% and 82.4% of inhibition. Procymidone and fluazinam if combined or not with benzalkonium chloride were the most effective in controlling sclerotinia stem rot under field conditions when applied at the onset of flowering and 15 days later. In the 2009-10 harvest, these two fungicides reduced the incidence of Sclerotinia stem rot by 73.1 and 71.6% and in the 2010-11 harvest by 75.7 and 77.6%, respectively.

  20. First report of frosty pod rot caused by Moniliophthora roreri on cacao in Bolivia

    Science.gov (United States)

    Frosty pod rot (FPR) is a devastating cacao disease caused by the basidiomycete Moniliophthora roreri (Aime and Phillips-Mora, 2005). The disease is confined to 13 countries in Central and South America and constitutes a permanent threat for cacao cultivation worldwide. In July 2012, FPR was detect...

  1. Status of maize stalk rot complex in western belts of Nepal and its integrated management

    Directory of Open Access Journals (Sweden)

    Subash Subedi

    2016-12-01

    Full Text Available Maize stalk rot complex is becoming a serious threat for maize growing areas of Nepal. A field monitoring for maize stalk rot complex was done during crop season (August, 2016 covering 10 farmers field each of Surkhet, Banke, Dang, Chitwan and Nawalparasi districts. Maize crop showed highly susceptible reaction to the disease at western belts of Dang and susceptible reaction was marked in Chitwan and Nawalparasi districts while the disease effect was mild at Banke and Surkhet district. Most of the plant diseases managed successfully through the application of bio-control agents, host resistance, chemicals and other different cultural control methods. The result of field experiment conducted at Dang showed that all the treatments had significant (P≤0.05 effect on percent disease index (PDI and crop yield over farmers practice to control maize stalk rot. The higher percent disease control (52.36% and yield increase (40.29% were recorded from the plot sprayed with streptocyclin @ 2 g L-1 and insecticide (cypermethrin + chloropyrifos @ 2.5 ml L-1 of water during knee height and subsequent spray after 15 days interval as compared to farmers practice. Out of 30 genotypes, Rampur composit, Arun 2, Rampur 34, RamS03F08, TLBRS07F16 and Rampur 24 were found resistant against stalk rot complex with higher yield at Rampur Chitwan.

  2. Dry Rot of Raphia hookeri and its Effect on Proximate Composition ...

    African Journals Online (AJOL)

    Prof. Ogunji

    Dry Rot of Raphia hookeri and its Effect on Proximate. Composition of the ... composition shows that R. hookeri fruit contains high amounts of mineral elements required for good health .... temperature of 28 ± 20C for 7 days. After the .... juice. J Food Prot. 61(11): 1515- 1517. Association of Official Analytical Chemists. (1990).

  3. Nitrogen Fertilizer and Growth Regulator Impacts on Tuber Deformity, Rot, and Yield for Russet Potatoes

    Directory of Open Access Journals (Sweden)

    Mark S. Reiter

    2012-01-01

    Full Text Available Potatoes (Solanum tuberosum are an important high-value commodity for producers in the Mid-Atlantic Region. Current production recommendations were based on white potatoes, and practices for Russet potatoes have not been researched in this region. The objective of this study was to test impacts of N rate (0, 67, 134, 201, and 268 kg N ha−1, N application timing (100% applied with planter, 2-way split (30% with planter and 70% band applied approximately 30 days after planting at dragoff, and three-way split (30% with planter, 50% band applied prior to drag-off, and 20% band applied at first sight of bloom, and additions of the growth regulator maleic hydrazide (MH-30. We tested “Goldrush” and “Norkotah” Russet potato varieties on marketability, total yield, tuber deformity, and tuber soft rot incidence for sandy loam soils in the Mid-Atlantic. Overall, year variations were significant with substantial rots (up to 86.5% occurring in year 3. Maleic hydrazide and N application timing had little consistent effect on any tested parameter. Nitrogen rate and variety factors had the greatest impacts on deformity, tuber rots, and yields for Russet potatoes in the Mid-Atlantic Region with 134 kg N ha−1 producing the highest total yields in 2009 and 2010. If tuber rots can be controlled, both “Goldrush” and “Norkotah” are acceptable varieties under the Mid-Atlantic production practices.

  4. Phytophthora megakarya, a causal agent of black pod rot in Africa

    Science.gov (United States)

    In most parts of the world where Theobroma cacao is grown, Phytophthora palmivora is the major concern for causing black pod rot (BPR). Phytophthora megakarya, on the other hand, occurs only in Africa, but represents a major threat to cacao production, the countries of West Africa being the largest ...

  5. Influence of fruit age on Phytophthora fruit rot development on susceptible and resistant watermelon germplasm

    Science.gov (United States)

    Phytophthora fruit rot of watermelon caused by Phytophthora capsici is an emerging disease in the southeastern United States. The disease has resulted in severe losses to watermelon growers in GA, SC, and NC, and is considered a top-research priority by the National Watermelon Association. We releas...

  6. Control of potato soft rot caused by Pectobacterium carotovorum and Pectobacterium atrosepticum by Moroccan actinobacteria isolates.

    Science.gov (United States)

    Baz, M; Lahbabi, D; Samri, S; Val, F; Hamelin, G; Madore, I; Bouarab, K; Beaulieu, C; Ennaji, M M; Barakate, Mustapha

    2012-01-01

    Pectobacterium carotovorum and Pectobacterium atrosepticum are dreadful causal agents of potato soft rot. Actually, there are no efficient bactericides used to protect potato against Pectobacterium spp. Biological control using actinobacteria could be an interesting approach to manage this disease. Thus, two hundred actinobacteria isolated from Moroccan habitats were tested for their ability to inhibit in vitro 4 environmental Pectobacterium strains and the two reference strains (P. carotovorum CFBP 5890 and P. atrosepticum CFBP 5889). Eight percent of these isolates were active against at least one of the tested pathogens and only 2% exhibited an antimicrobial activity against all tested Pectobacterium strains. Four bioactive isolates having the greatest pathogen inhibitory capabilities and classified as belonging to the genus Streptomyces species through 16S rDNA analysis were subsequently tested for their ability to reduce in vivo soft rot symptoms on potato slices of Bintje, Yukon Gold, Russet and Norland cultivars caused by the two pathogens P. carotovorum and P. atrosepticum. This test was carried out by using biomass inoculums and culture filtrate of the isolates as treatment. Among these, strain Streptomyces sp. OE7, reduced by 65-94% symptom severity caused by the two pathogens on potato slices. Streptomyces OE7 showed a potential for controlling soft rot on potato slices and could be useful in an integrated control program against potato soft rot pathogens in the objective to reduce treatments with chemical compounds.

  7. Characterization of Basidiomycetes associated with wood rot of citrus in southern Italy.

    Science.gov (United States)

    Roccotelli, Angela; Schena, Leonardo; Sanzani, Simona M; Cacciola, Santa O; Mosca, Saveria; Faedda, Roberto; Ippolito, Antonio; di San Lio, Gaetano Magnano

    2014-08-01

    The characterization of Basidiomycetes associated with wood rots in commercial citrus orchards in southern Italy revealed that both white and brown rot fungi are implicated in this disease. Fomitiporia mediterranea was the most prevalent species causing a white rot, followed by Fomitopsis sp. which, by contrast, was associated with brown rot wood decay. Furthermore, Phellinus spp. and other nonidentified basidiomycetous fungi showing genetic affinity with the genera Phellinus and Coniophora were occasionally isolated. Artificial inoculations on lemon (Citrus limon) branches showed a faster wood colonization by Fomitopsis sp. compared with F. mediterranea, indicating that the former species as a potentially serious pathogen of citrus trees. The analysis of F. mediterranea internal transcribed spacer (ITS) sequences revealed a high level of genetic variability, with 13 genotypes which were both homozygous (6 genotypes) and heterozygous (7 genotypes). The presence of heterozygous genomes based on ITS sequences has never been reported before for F. mediterranea. This, together with the high frequency of basidiomata on infected wood, unambiguously confirms the outcrossing nature of reproduction in F. mediterranea and the primary role of basidiospores in the dissemination of inoculum. Similarly, high genetic variability was observed analyzing Fomitopsis sp. Because basidiomata of this fungus have not been observed on citrus trees, it can be hypothesized that basidiospores are produced on alternative host plants.

  8. Mechanism of antibacterial activity of the white-rot fungus Hypholoma fasciculare colonizing wood

    NARCIS (Netherlands)

    De Boer, W.; Folman, L.B.; Klein Gunnewiek, P.J.A.; Svensson, T.; Bastviken, D.; Oberg, G.; Del Rio, J.C.; Boddy, L.

    2010-01-01

    In a previous study it was shown that the number of wood-inhabiting bacteria was drastically reduced after colonization of beech (Fagus sylvatica) wood blocks by the white-rot fungus Hypholoma fasciculare, or sulfur tuft (Folman et al. 2008). Here we report on the mechanisms of this fungal-induced a

  9. Polycyclic aromatic hydrocarbon degradation by the white rot fungus Bjerkandera sp. strain BOS55

    NARCIS (Netherlands)

    Kotterman, M.

    1998-01-01

    Outline of this thesis
    In this thesis the conditions for optimal PAH oxidation by the white rot fungus Bjerkandera sp. strain BOS55 were evaluated. In Chapter 2, culture conditions like aeration and cosubstrate concentrations,

  10. Improving ruminal degradability of oil palm fronds using white rot fungi

    NARCIS (Netherlands)

    Rahman, M.M.; Lourenco, M.; Hassim, H.A.; Baars, J.J.P.; Sonnenberg, A.S.M.; Cone, J.W.; Boever, de J.L.; Fievez, V.

    2011-01-01

    The use of oil palm fronds (OPF) in livestock production is limited as up to 0.20 of their dry biomass is lignin. White rot fungi (WRF) are very effective basidiomycetes for biological pre-treatment as they degrade lignin extensively. Ten WRF were screened for their potential to increase OPF digesti

  11. Polycyclic aromatic hydrocarbon degradation by the white rot fungus Bjerkandera sp. strain BOS55

    NARCIS (Netherlands)

    Kotterman, M.

    1998-01-01

    Outline of this thesis
    In this thesis the conditions for optimal PAH oxidation by the white rot fungus Bjerkandera sp. strain BOS55 were evaluated. In Chapter 2, culture conditions like aeration and cosubstrate concentrations, whic

  12. Pythium and Fusarium species causing seed rot and damping-off of alfalfa

    Science.gov (United States)

    Seed rot and damping-off is an important disease of alfalfa, severely affecting stand establishment when conditions favor the disease. This disease may have been overlooked as a cause of poor stand establishment and reduced vigor of adult plants. Globally, 15 Pythium species have been found to cause...

  13. Biodegradation of pentachlorophenol by the white rot fungus Phanerochaete chrysosporium (1988)

    Science.gov (United States)

    Extensive biodegradation of pentachlorophenol (PCP) by the white rot fungus Phanerochaete chrysosporium was demonstrated by the disappearance and mineralization of [14C]PCP in nutrient nitrogen-limited culture. Mass balance analyses demonstrated the formation of water-soluble met...

  14. First report of truncatella angustata causing postharvest rot on ‘topaz’ apples in the Netherlands

    NARCIS (Netherlands)

    Wenneker, M.; Pham, K.T.K.; Boekhoudt, L.C.; Boer, de F.A.; Leeuwen, van P.J.; Hollinger, T.C.; Thomma, B.P.H.J.

    2017-01-01

    In the Netherlands, about 30% of the organic apple (Malus domestica Borkh.) production consists of apple scab resistant cultivars, such as Topaz and Santana. However, organic ‘Topaz’ apples show a high incidence of fungal rot after storage. Hot-water treatment (HWT) of freshly harvested apple fru

  15. Incidence and Severity of Maize Ear Rots and Factors Responsible for Their Occurrence in Uganda

    Science.gov (United States)

    Bigirwa, G.; Kaaya, A. N.; Sseruwu, G.; Adipala, E.; Okanya, S.

    Eleven major maize growing districts of Uganda were surveyed for three consecutive seasons between 2002 and 2003 to establish maize ear rot incidence and severity. Sternocarpella maydis and Fusarium species particularly F. graminearum and F. verticillioides were the identified maize ear rot causing fungi. Incidence of S. maydis ranged from 2.5 to 32.5% while that of Fusarium sp. was in the range of 1.9 and 15.3%. In districts of higher altitude (above 1,800 m above sea level) F. graminearum dominated in all seasons while in districts with an altitude between 900 and 1,500 m above sea level, S. maydis was the major cause of ear rots. This observation was attributed to differences in temperature, altitude and rainfall. There was a strong positive correlation (p = 0.001) between incidence and severity for S. maydis and a weak one for Fusarium sp. because the latter would rarely infect the entire cob unlike the former. All farmers expressed concern about the quality of maize due to ear rots and sort out infected grain after harvest. However, varied uses of infected grain were noted. For example, in Kapchorwa district 82% of the respondents indicated that the infected grain is used for making local brew because the moulds give it a good taste and aroma, while in Kamuli and Masaka districts, 36% use it as animal feed ingredient. This indicates that people and animals could be ingesting mycotoxins unknowingly thus the need for sensitization programmes.

  16. Molecular phylogenetics of the Gloeophyllales and relative ages of clades of Agaricomycotina producing a brown rot.

    Science.gov (United States)

    Garcia-Sandoval, Ricardo; Wang, Zheng; Binder, Manfred; Hibbett, David S

    2011-01-01

    The Gloeophyllales is a recently described order of Agaricomycotina containing a morphologically diverse array of polypores (Gloeophyllum), agarics (Neolentinus, Heliocybe) and resupinate fungi (Veluti-Veluticeps, Boreostereum, Chaetodermella), most of which have been demonstrated to produce a brown-rot mode of wood decay and are found preferentially on coniferous substrates. Multiple phylogenetic studies have included taxa of Gloeophyllales, but none have sampled the order thoroughly, and so far only ribosomal RNA genes have been used. Consequently the limits and higher level placement of the Gloeophyllales are obscure. We obtained sequence data for three protein-coding genes (rpb2, atp6, tef1) and three rRNA regions (nuc-ssu, nuc-lsu, 5.8S) in 19 species of Gloeophyllales representing seven genera and analyzed them together with a diverse set of Agaricomycotina, emphasizing Polyporales. Boreostereum, which is suspected to produce a white rot, is the sister group of the rest of the Gloeophyllales, all of which produce a brown rot. Gloeophyllum contains at least two independent clades, one of which might correspond to the genus Osmoporus. White rot and resupinate fruiting bodies appear to be plesiomorphic in Gloeophyllales. Relaxed molecular clock analyses suggest that the Gloeophyllales arose in the Cretaceous, after the origin of Pinaceae.

  17. Polycyclic aromatic hydrocarbon degradation by the white rot fungus Bjerkandera sp. strain BOS55.

    NARCIS (Netherlands)

    Kotterman, M.J.J.

    1998-01-01

    Outline of this thesisIn this thesis the conditions for optimal PAH oxidation by the white rot fungus Bjerkandera sp. strain BOS55 were evaluated. In Chapter 2, culture conditions like aeration and cosubstrate concentrations, which influenced the oxidation of the PAH compound anthra

  18. Agrobacterium-mediated transformation of the white-rot fungus Physisporinus vitreus.

    Science.gov (United States)

    Schubert, M; Stührk, C; Fuhr, M J; Schwarze, F W M R

    2013-11-01

    The biotechnologically important white-rot fungus Physisporinus vitreus was co-cultivated with Agrobacterium tumefaciens AGL-1 carrying plasmids with nourseothricin resistance as the selectable marker gene and red fluorescence protein as a visual marker. Mitotically stable transformed isolates were obtained showing red fluorescence protein activity.

  19. Use of Pseudomonas aeruginosa in the control od root-knot disease complex in tomato: the effects of different inoculum levels of Meloidogyne javanica and Rhizoctonia solani

    Directory of Open Access Journals (Sweden)

    I. A. Siddiqui

    2013-12-01

    Full Text Available The potential impact of Pseudomons aeruginosa strain IE-6 as a biological control agent against Meloidogyne javanica at four inoculum densities (0, 250, 500 and 1000 eggs/plant and Rhizoctonia solani at three inoeulum levels (0, 1 and 3 ml culture suspension/kg of soil was examined on tomato in the greenhouse experiments. The biocontrol bacterium suppressed root infection caused by R. solani and M. javanica on tomato in both sterilized and non-sterilized soils. Root-rot infection increased with the increase in pathogen(s concentration. P. aeruginosa showed better biocontrol effects at low population levels of M.javanica and R. solani than at higher population densities of the pathogen(s. Root-rot disease severity was more pronounced in sterilized soil compared to the non-sterilized one. Soil infested with high population densities ofR. solani (3 ml /kg of soil and M. javanica (2000 eggs/pot resulted in complete mortality of tomato seedlings in sterilized soil, whereas some plants were found to survive in non-stenlized soil. There seems to be a correlation between population density of M. javanica and root colonization by R. solani. Root colonization by other three root-infecting fungi including Macrophomina phaseolina, Fusarium oxysporum and Fusarium solani was also lower in the presence of P. aeruginosa in non-sterilized soil. P. aeruginosa enhanced plant growth in both types of soil.

  20. Root canal irrigants.

    Science.gov (United States)

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-10-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were 'root canal irrigants' and 'endodontic irrigants.' The reference lists of each article were manually checked for additional articles of relevance.

  1. Conjoined lumbosacral nerve roots

    Directory of Open Access Journals (Sweden)

    Atila Yılmaz

    2012-03-01

    Full Text Available Lumbosacral nerve root anomalies are a rare group ofcongenital anatomical anomalies. Various types of anomaliesof the lumbosacral nerve roots have been documentedin the available international literature. Ttheseanomalies may consist of a bifid, conjoined structure, ofa transverse course or of a characteristic anastomizedappearance. Firstly described as an incidental findingduring autopsies or surgical procedures performed forlumbar disk herniations and often asymptomatic, lumbosacralnerve root anomalies have been more frequentlydescribed in the last years due to the advances made inradiological diagnosis.

  2. ISOLATION AND IDENTIFICATION OF BACTERIAL CAUSED SOFT ROT DISEASE ON CARROT (Daucus carota L.) LOCAL VARIETY IN BALI

    OpenAIRE

    Ni Wayan Desi Bintari; Retno Kawuri; Meitini Wahyuni Proborini

    2015-01-01

    Soft rot bacteria infection in carrot tuber (D. carota L.) causes severe economic losses. Soft rot disease can be caused by various bacteria belonging to Enterobacteriaceae. This study aimed to isolate and identify bacteria as causal agent of soft rot disease in local carrot variety in Bali. Samples were collected at Badung Tradisional Market, Denpasar, Bali. Isolation was carried out by serial dilution method (Platting Method). Eight bacteria (BL1, BL2, BL3, BL4, BL5, BL6, BL7 and BL8) were ...

  3. Decolorization of reactive brilliant red K-2BP with the white- rot fungi under non-sterile conditions

    Institute of Scientific and Technical Information of China (English)

    GAO Dawen; WEN Xianghua; QIAN Yi

    2004-01-01

    @@ In recent years, many researches indicate that white rot fungus is a promising microbe in wastewater treatment. The basidiomycete Phanerochaete chrysosporium in white rot fungi is the most extensively studied and discussed[1]. The extracellular ligninolytic enzymes of white rot fungi have the ability to degrade a wide spectrum of recalcitrant organo-pollutants such as chlorinated phenols and various types of synthetic dyes because of their nonspecific characteristics[2-6]. And some significant mineralization (20%-48%) was observed during degradation of azo dyes[7].

  4. Occurrence, characterization and management of fruit rot of immature cucumber fruits under arid greenhouse conditions

    Directory of Open Access Journals (Sweden)

    ABDULLAH M AL-SADI

    2012-01-01

    Full Text Available A study was undertaken to characterize and manage pathogens associated with fruit rot of immature cucumber fruits in greenhouses in Oman. A survey over 5 growing seasons from 2008 to 2010 in 99 different greenhouses in Oman showed that the disease is prevalent in 91 (92% greenhouses and results in losses of 10 to 60% (avg. 33% of immature fruits per plant. Incidence of the disease was not found to be affected by growing seasons, which could be attributed to the limited fluctuations in ambient temperatures in greenhouses. Isolations from diseased cucumber fruits yielded Alternaria alternata (isolation frequency = 52%, Fusarium equiseti (40%, Cladosporium tenuissium (27%, Botrytis cinerea (6%, Fusarium solani (6%, Corynespora cassiicola (3%, Aspergillus spp. (2%, Curvularia sp. (1% and Bipolaris sp. (1%. With the exception of Curvularia and Bipolaris species, all other fungi were pathogenic on cucumber fruits, with Fusarium equiseti being the most aggressive, followed by Corynespora cassiicola, Botrytis cinerea and Alternaria alternata. Cladosporium and Aspergillus spp. were found to be weakly pathogenic. Comparing the efficacy of foliar and soil applications of carbendazim fungicide on fruit rot of cucumber showed that foliar applications significantly reduced fruit rot and increased cucumber yield when compared to soil application or to control (P < 0.01. This appears to be the first report of the association of Corynespora cassiicola and Fusarium equiseti with fruit rot of immature greenhouse cucumbers. This is also the first report in Oman for the association of Cladosporium tenuissimum with fruit rot of immature cucumbers. Findings are discussed in terms of factors affecting disease control in greenhouses using carbendazim.

  5. Effects of bunch rot (Botrytis cinerea) and powdery mildew (Erysiphe necator) fungal diseases on wine aroma

    Science.gov (United States)

    Lopez Pinar, Angela; Rauhut, Doris; Ruehl, Ernst; Buettner, Andrea

    2017-03-01

    This study aimed to characterize the effects of bunch rot and powdery mildew on the primary quality parameter of wine, the aroma. The influence of these fungal diseases was studied by comparative Aroma Extract Dilution Analyses (AEDA) and sensory tests. The effect of bunch rot was investigated on three grape varieties, namely White Riesling, Red Riesling and Gewürztraminer and that of powdery mildew on the hybrid Gm 8622-3; thereby, samples were selected that showed pronounced cases of infection to elaborate potential currently unknown effects. Both infections revealed aromatic differences induced by these fungi. The sensory changes were not associated with one specific compound only, but were due to quantitative variations of diverse substances. Bunch rot predominantly induced an increase in the intensities of peach-like/fruity, floral and liquor-like/toasty aroma notes. These effects were found to be related to variations in aroma substance composition as monitored via AEDA, mainly an increase in the FD factors of lactones and a general moderate increase of esters and alcohols. On the other hand, powdery mildew decreased the vanilla-like character of the wine while the remaining sensory attributes were rather unaffected. Correspondingly, FD factors of the main aroma constituents were either the same or only slightly modified by this disease. Moreover, bunch rot influenced the aroma profiles of the three varieties studied to a different degree. In hedonic evaluation, bunch rot-affected samples were rated as being more pleasant in comparison to their healthy controls in all three varieties while the powdery mildew-affected sample was rated as being less pleasant than its healthy control.

  6. Scholarly context not found: one in five articles suffers from reference rot.

    Directory of Open Access Journals (Sweden)

    Martin Klein

    Full Text Available The emergence of the web has fundamentally affected most aspects of information communication, including scholarly communication. The immediacy that characterizes publishing information to the web, as well as accessing it, allows for a dramatic increase in the speed of dissemination of scholarly knowledge. But, the transition from a paper-based to a web-based scholarly communication system also poses challenges. In this paper, we focus on reference rot, the combination of link rot and content drift to which references to web resources included in Science, Technology, and Medicine (STM articles are subject. We investigate the extent to which reference rot impacts the ability to revisit the web context that surrounds STM articles some time after their publication. We do so on the basis of a vast collection of articles from three corpora that span publication years 1997 to 2012. For over one million references to web resources extracted from over 3.5 million articles, we determine whether the HTTP URI is still responsive on the live web and whether web archives contain an archived snapshot representative of the state the referenced resource had at the time it was referenced. We observe that the fraction of articles containing references to web resources is growing steadily over time. We find one out of five STM articles suffering from reference rot, meaning it is impossible to revisit the web context that surrounds them some time after their publication. When only considering STM articles that contain references to web resources, this fraction increases to seven out of ten. We suggest that, in order to safeguard the long-term integrity of the web-based scholarly record, robust solutions to combat the reference rot problem are required. In conclusion, we provide a brief insight into the directions that are explored with this regard in the context of the Hiberlink project.

  7. Susceptibility of Maize to Stalk Rot Caused by Fusarium graminearum Deoxynivalenol and Zearalenone Mutants.

    Science.gov (United States)

    Quesada-Ocampo, L M; Al-Haddad, J; Scruggs, A C; Buell, C R; Trail, F

    2016-08-01

    Fusarium graminearum is a destructive pathogen of cereals that can cause stalk rot in maize. Stalk rot results in yield losses due to impaired grain filling, premature senescence, and lodging, which limits production and harvesting of ears. In addition, mycotoxins can make infected tissues unfit for silage. Our objectives were to evaluate the natural variation in stalk rot resistance among maize inbreds, to establish whether deoxynivalenol (DON)- and zearalenone (ZEA)-deficient strains are pathogenic on a panel of diverse inbreds, and to quantify the accumulation of DON in infected stalk tissue. Wild-type F. graminearum and mycotoxin mutants (DON and ZEA) were used to separately inoculate stalks of 9-week-old plants of 20 inbreds in the greenhouse. Plants were evaluated for lesion area at the inoculation point at 0, 2, 14, and 28 days postinoculation and tissues around lesions were sampled to determine the DON content. Regardless of their ability to produce DON or ZEA, all tested F. graminearum strains caused stalk rot; however, significant differences in disease levels were detected. Among the tested inbreds, Mp717 was resistant to all three F. graminearum strains while Mp317 and HP301 were only partially resistant. Accumulation of DON was significantly lower in infected stalks of the resistant and partially resistant inbreds than the susceptible inbreds. Analysis of the 20 inbreds using data from 17 simple-sequence repeats revealed population structure among the individuals; however, there was no association between genetic clustering and stalk rot resistance. These findings are an additional step toward breeding maize inbreds suitable for planting in fields infested with F. graminearum.

  8. The Efficiency of Trichoderma harzianum and Aneurinobacillus migulanus in the Control of Gladiolus Corm Rot in Soil-Less Culture System

    Directory of Open Access Journals (Sweden)

    Nosir Walid

    2010-01-01

    Full Text Available Problem statement: Gladiolus is cultivated commonly for cut flower production, frequently as a protected crop. The glasshouse or polytunnel environment, providing excellent conditions for flower production, also make conditions more favorable for disease to develop. Approach: The pathogen Fusarium oxysporum f. sp. gladioli causes wilt diseases in a wide range of economically important plants and can have devastating effects on crop production. Trichoderma harzianum and Aneurinobacillus migulanus were tested separately and in combination for controlling F. oxysporum f. sp. gladioli activity in soilless culture using Perlite as the substrate. Results: The efficiency of both of antagonists against corm rot was evaluated based on vegetative and root growth parameters and on flowering parameters. T. harzianum was more effective than A. migulanus in disease suppression and also enhanced plant growth, increased flower production and quality. A. migulanus enhanced plant growth when tested alone. The mixture of antagonists reduced the efficiency of T. harzianum. Numbers of T. harzianum CFU in the substrate and on corms increased following application compared with treating with both antagonists. No T. harzianum was detected in the substrate by 120 day after planting, however, A. migulanus CFU significantly decreased on corms when inoculated in combination with T. harzianum and F. oxysporum f. sp. gladioli. However, A. migulanus CFU was not detected in the substrate of the same combination. SEM and Glasshouse results suggested that suppressive mechanisms of T. harzianum and A. migulanus differed. T. harzianum appeared to operate through a combination of antibiosis and substrate competition, whereas A. migulanus produced an electron-dense substance which may have inhibited the penetration of host tissues by F. oxysporum f. sp. gladiolus. Greater growth of T. harzianum was observed when inoculated alone or with F. oxysporum f. sp

  9. The ectomycorrhizal fungus Paxillus involutus converts organic matter in plant litter using a trimmed brown-rot mechanism involving Fenton chemistry

    Science.gov (United States)

    Rineau, Francois; Roth, Doris; Shah, Firoz; Smits, Mark; Johansson, Tomas; Canbäck, Björn; Olsen, Peter Bjarke; Persson, Per; Grell, Morten Nedergaard; Lindquist, Erika; Grigoriev, Igor V; Lange, Lene; Tunlid, Anders

    2012-01-01

    Soils in boreal forests contain large stocks of carbon. Plants are the main source of this carbon through tissue residues and root exudates. A major part of the exudates are allocated to symbiotic ectomycorrhizal fungi. In return, the plant receives nutrients, in particular nitrogen from the mycorrhizal fungi. To capture the nitrogen, the fungi must at least partly disrupt the recalcitrant organic matter–protein complexes within which the nitrogen is embedded. This disruption process is poorly characterized. We used spectroscopic analyses and transcriptome profiling to examine the mechanism by which the ectomycorrhizal fungus Paxillus involutus degrades organic matter when acquiring nitrogen from plant litter. The fungus partially degraded polysaccharides and modified the structure of polyphenols. The observed chemical changes were consistent with a hydroxyl radical attack, involving Fenton chemistry similar to that of brown-rot fungi. The set of enzymes expressed by Pa. involutus during the degradation of the organic matter was similar to the set of enzymes involved in the oxidative degradation of wood by brown-rot fungi. However, Pa. involutus lacked transcripts encoding extracellular enzymes needed for metabolizing the released carbon. The saprotrophic activity has been reduced to a radical-based biodegradation system that can efficiently disrupt the organic matter–protein complexes and thereby mobilize the entrapped nutrients. We suggest that the released carbon then becomes available for further degradation and assimilation by commensal microbes, and that these activities have been lost in ectomycorrhizal fungi as an adaptation to symbiotic growth on host photosynthate. The interdependence of ectomycorrhizal symbionts and saprophytic microbes would provide a key link in the turnover of nutrients and carbon in forest ecosystems. PMID:22469289

  10. Study on Prevention and Control Technique of Pickled Radish Soft Rot%泡菜萝卜软腐病防治技术研究

    Institute of Scientific and Technical Information of China (English)

    冉茂林; 彭化贤; 刘独臣; 雍晓平; 陈琳

    2012-01-01

    Through influencing factors screening of disease resistance, different varieties, chemistry agents, planting ways and soil disinfection ways prevention and control technique of pickle radish soft rot was put forward. The ways were disease resistance/tolerance variety of pickled radish selecton, such as Luluo 5, long-white Japanese radish, C9292; ridge culture adopton, and rotaton different types of same species and rotating different crop plant. Soft rot could be effectively reduced by this method: soil disinfect with lime 2.25 t/hm2 before sowing seeds, "kejia" 2 000 mg/kg or thiazole copper 1 500 mg/kg to sprinkle radish root at the early infection once a week for 3 times.%通过不同萝卜品种抗病性筛选,不同化学药剂、种植方式及土壤消毒方式对萝卜软腐病的影响研究,提出泡菜萝卜软腐病防治技术.结果表明,选用抗(耐)病萝卜品种如泸萝5号、日本长白萝卜、C9292,采用垄作,同种不同类型萝卜品种轮作或不同作物轮茬,播种前每公顷土壤用石灰2.25 t撒施消毒,发病初期用科佳2000 mL/L或噻唑铜1500 mL/L淋根,每隔7d淋灌一次,连续3次,可有效减轻萝卜软腐病的发生.

  11. Economic strategies of plant absorptive roots vary with root diameter

    Science.gov (United States)

    Kong, D. L.; Wang, J. J.; Kardol, P.; Wu, H. F.; Zeng, H.; Deng, X. B.; Deng, Y.

    2016-01-01

    Plant roots typically vary along a dominant ecological axis, the root economics spectrum, depicting a tradeoff between resource acquisition and conservation. For absorptive roots, which are mainly responsible for resource acquisition, we hypothesized that root economic strategies differ with increasing root diameter. To test this hypothesis, we used seven plant species (a fern, a conifer, and five angiosperms from south China) for which we separated absorptive roots into two categories: thin roots (thickness of root cortex plus epidermis perspective on our understanding of the root economics spectrum.

  12. Registration of SR98 sugar beet germplasm with resistances to Rhizoctonia seedling and crown and root rot diseases

    Science.gov (United States)

    Sugar beet (Beta vulgaris L.) germplasms SR98 (PI 655951) and SR98/2 (659754) are being released as potential pollinators or populations from which to select pollinators for hybrid seed production, and were developed by the USDA-ARS, at East Lansing, MI, in cooperation with the Beet Sugar Developmen...

  13. Involvement of phenazines and biosurfactants in biocontrol of Pythium myriotylum root rot on cocoyam by Pseudomonas sp. CMR12A

    Science.gov (United States)

    Pseudomonas sp. CMR12a was isolated from the rhizosphere of the tropical tuber crop cocoyam and produces both phenazines and cyclic lipopeptide (CLP) biosurfactants. CMR12a was shown to be an efficient biocontrol agent of P. myriotylum on cocoyam. To assess the importance of phenazine and biosurfact...

  14. Microbial antagonism as a potential solution for controlling selected root pathogens of crops

    Science.gov (United States)

    Cooper, Sarah; Agnew, Linda; Pereg, Lily

    2016-04-01

    Root pathogens of crops can cause large reduction in yield, however, there is a limited range of effective methods to control such pathogens. Soilborne pathogens that infect roots often need to survive in the rhizosphere, where there is high competition from other organisms. In such hot spots of microbial activity and growth, supported by root exudates, microbes have evolved antagonistic mechanisms that give them competitive advantages in winning the limited resources. Among these mechanisms is antibiosis, with production of some significant antifungal compounds including, antibiotics, volatile organic compounds, hydrogen cyanide and lytic enzymes. Some of these mechanisms may suppress disease through controlling the growth of root pathogens. In this project we isolated various fungi and bacteria that suppress the growth of cotton pathogens in vitro. The pathogen-suppressive microbes were isolated from cotton production soils that are under different management strategies, with and without the use of organic amendments. The potential of pathogen-suppressing microbes for controlling the black root rot disease, caused by the soilborne pathogen Thielaviopsis basicola, was confirmed using soil assays. We identified isolates with potential use as inoculant for cotton production in Australia. Having isolated a diverse group of antagonistic microbes enhances the probability that some would survive well in the soil and provide an alternative approach to address the problem of root disease affecting agricultural crops.

  15. Chromatic roots and hamiltonian paths

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2000-01-01

    We present a new connection between colorings and hamiltonian paths: If the chromatic polynomial of a graph has a noninteger root less than or equal to t(n) = 2/3 + 1/3 (3)root (26 + 6 root (33)) + 1/3 (3)root (26 - 6 root (33)) = 1.29559.... then the graph has no hamiltonian path. This result...

  16. Biological control of botrytis bunch rot in organic wine grapes with the yeast antagonist Candida sake CPA‐1

    National Research Council Canada - National Science Library

    Calvo‐Garrido, C; Elmer, P. A. G; Viñas, I; Usall, J; Bartra, E; Teixidó, N

    2013-01-01

    ... ‐1 in suppressing botrytis bunch rot development, in an organic vineyard under M editerranean conditions for two seasons, and compare its performance with that of two biologically based products...

  17. NODC Standard Format Pathology Data Sets (1973-1975): Fin Rot (F006) Data (NODC Accession 0014147)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Fin Rot (F006) dataset contains data from examinations of the biological condition of diseased fishes. For tow samples collected, data include: total number of...

  18. Growth kinetics and efficacy as parameters for ranking and selecting biocontrol agents that reduce pink rot in stored potatoes

    Science.gov (United States)

    Increased production of organic agricultural products and the relative ineffectiveness of traditional control measures support development of new biocontrol technologies for use against pink rot infections in storage. The microbiota of 84 different agricultural soils was individually transferred to...

  19. Antagonistic and Biocontrol Potential of Trichoderma asperellum ZJSX5003 Against the Maize Stalk Rot Pathogen Fusarium graminearum

    National Research Council Canada - National Science Library

    Li, Yaqian; Sun, Ruiyan; Yu, Jia; Saravanakumar, Kandasamy; Chen, Jie

    2016-01-01

    ...) the causal agent of corn stalk rot of maize were in vitro for their antagonistic properties followed by statistical model of principal compound analysis to identify the beneficial antagonist T. asperellum strain...

  20. BIODEGRADATION OF ENVIRONMENTAL POLLUTANTS BY THE WHITE ROT FUNGUS PHANEROCHAETE CHRYSOPORIUM: INVOLVEMENT OF THE LIGNIN DEGRADING SYSTEM

    Science.gov (United States)

    The white-rot fungus Phanrochaete chrysosporium has the ability to degrade a wide variety of structurally diverse organic compounds, including a number of environmentally persistent organopollutants. The unique biodegradative abilities of this fungus appears to be depend...