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Sample records for black root rot

  1. 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...

  2. Etiology of phomopsis root rot in soybean

    Directory of Open Access Journals (Sweden)

    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.

  3. 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. PMID:22212462

  4. Heterobasidion root rot in Norway spruce

    OpenAIRE

    Thor, Magnus

    2005-01-01

    In spite of its biological and economic impact on Swedish forestry, root rot caused by Heterobasidion annosum (Fr.) Bref. sensu lato has received no or little attention in forest planning. This thesis summarizes and discusses two experiments involving prophylactic treatment of stumps, and three investigations on the modelling and simulation of root rot in coniferous stands with special emphasis on Norway spruce (Picea abies [L.] Karst.). In 14 previously unthinned stands of Norway spruce, the...

  5. 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...

  6. 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.

  7. 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

    2015-01-01

    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. PMID:26214435

  8. 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.

  9. 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.

  10. Root rot diseases of sugar beet

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. Stand tending and root rot in Norway spruce stands - economical effects caused by root rot at different thinning regimes

    International Nuclear Information System (INIS)

    This report is divided into three parts: 1) a literature study describing the most common fungi causing rot in wood and descriptions of various strategies to reduce economic loss from root rot, 2) a check of a model describing the development of butt rot in pure Norway spruce plantations in southern Sweden, and 3) simulated economic effects of root rot in stands with various stand tending. The rot model was used to estimate future rot frequencies in the economic calculations. In order to avoid overestimations of rot frequencies, the calculations were also executed when assuming slower growth of rot than shown in the model. When analysing the economical effects of rot, the following three thinning programmes were used: Program 1: thinning at the ages of 30- and 45 years. Final felling at the ages 50-, 55-, 60-, 65-, and 70 years. Program 2: thinning at the ages of 40- and 60- years. Final felling at the ages 65 and 75 years. Program 3: thinning at the ages of 30-, 40-, 55-, and 70 years. Final felling at the ages 80 and 90 years. With an interest rate of 3%, programme 2 (final felling at the age of 65 years) had the highest value at present. This result was valid when presuming butt rot in the stand as well as when presuming no butt rot in the stand. There was a small difference between the value at present in programme 1 (final felling at the age of 60 years) and in programme 3 (final felling at the age of 80 years). When presuming butt rot in the stand, the value at present in programme 3 decreased somewhat more in comparison to the value at present in programme 1. Compared to no butt rot in the stand, the optimal final felling time appeared five to ten years earlier when assuming butt rot in the stand. Stand tending programme 1 and an interest rate of 3% were used. Interest rates 2 and 4% did not indicate shorter rotation. The calculated optimal time of final felling appeared at the same stand age whether assuming rot preset or not. The results in this study

  13. Root rot of sugarbeet in the Vojvodina Province

    Directory of Open Access Journals (Sweden)

    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

  14. 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

  15. Root rots of common and tepary beans in Puerto Rico

    Science.gov (United States)

    Root rots are a disease complex affecting common bean and can be severe in bean growing areas in the tropics and subtropics. The presence of several pathogens makes it difficult to breed for resistance because of the synergistic effect of the pathogens in the host and the interaction of soil factors...

  16. Phytophthora root rot resistance in soybean E00003

    Science.gov (United States)

    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...

  17. 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

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

    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.

  19. Resistance to black rot in a Spanish Brassica collection.

    OpenAIRE

    Lema Márquez, Margarita; Soengas Fernández, María del Pilar; Velasco Pazos, Pablo; Abilleira Ambroa, Rosaura; Cartea González, María Elena

    2011-01-01

    Xanthomonas campestris pv. campestris (Xcc), causal agent of black rot, is widely distributed around the world in Brassica crops causing severe yield losses. The seedborne bacteria can survive in crop debris or crucifer weeds, introducing in the plant through hydathodes and wounds. While in warm and humid regions Xcc can cause plant dead, in coastal temperate areas it produces necrotic lesions on leaf margin, which decrease the value of the product on fresh market. In northwestern Spain, blac...

  20. 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.

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

    Science.gov (United States)

    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...

  2. Monitoring cotton root rot progression within a growing season using airborne multispectral imagery

    Science.gov (United States)

    Cotton root rot, caused by the fungus Phymatotrichopsis omnivora, is a serious and destructive disease affecting cotton production in the southwestern United States. Accurate delineation of cotton root rot infections is important for cost-effective management of the disease. The objective of this st...

  3. Comparison of airborne multispectral and hyperspectral imagery for mapping cotton root rot

    Science.gov (United States)

    Cotton root rot, caused by the soilborne fungus, Phymatotrichum omnivorum, is a major cotton disease affecting cotton production in the southwestern and south central U.S. Accurate delineation of root rot infestations is necessary for cost-effective management of the disease. The objective of this s...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Incidence of root and butt rot in consecutive rotations of Picea abies

    Energy Technology Data Exchange (ETDEWEB)

    Roennberg, Jonas [Swedish Univ. of Agricultural Sciences, Alnarp (Sweden). Southern Swedish Forest Research Centre; Joergensen, B.B. [Danish Forest and Landscape Research Inst., Hoersholm (Denmark)

    2000-07-01

    The incidence of butt rot in two consecutive rotations of Norway spruce [Picea abies (L.) Karst.] in 28 permanent sample plots at four different sites in Denmark was evaluated. Incidence of butt rot was estimated by visual examination of stumps at final felling of the previous rotation and by examination of bore cores taken at the butt from a random sample of trees before first thinning of the subsequent rotation. There was no correlation between the incidence of butt rot at final felling of the previous rotation of Norway spruce and the incidence of butt rot at first thinning of the subsequent rotation of Norway spruce. The incidence of butt rot at final felling was between 19 and 100%, and at first thinning between 0 and 20%. The S-form of Heterobasidion annosum (Fr.) Bref. was the most commonly found decay-causing organism at all sites. Root systems of 28 trees without decay at stump height in the present rotation were excavated to estimate the incidence of root rot. Heterobasidion annosum was found in only one root. Resinicium bicolor (Alb. and Schw. ex Fr.) Parm. was found in 25% of the excavated root systems. The result of the study shows that the incidence of butt rot at first thinning of Norway spruce is not necessarily higher on sites where the previous rotation was heavily infected than on sites where infection in the previous rotation was low.

  7. Colonization Of Exopolysaccharide Producing Paenibacillus Polymyxa On Maize ( Zea Mays L.) Roots For Enhancing Resistance Against Root Rot Disease

    OpenAIRE

    T. Sheela; Usharani

    2013-01-01

    Root rot disease of maize (zae mays L) caused by the highly virulent strain of Aspergillus niger and Fusairum graminearam . The very important plant disease in India and other countries. Maize seeds infected by seed-borne fungi have been reported to produce seed abortion, reduced seed size, seed rot, seed necrosis, seed discoloration, reduce seed germination capacity and physiological alternation of seed. Biological control represents an attractive alternative for the future because for the m...

  8. Phytophthora Root and Crown Rot on Apples in Bulgaria

    Directory of Open Access Journals (Sweden)

    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

  9. 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. PMID:24808737

  10. 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

  11. 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

  12. Change detection of cotton root rot infection over a 10-year interval using airborne multispectral imagery

    Science.gov (United States)

    Cotton root rot is a very serious and destructive disease of cotton grown in the southwestern and south central United States. Accurate information regarding the spatial and temporal infections of the disease within fields is important for effective management and control of the disease. The objecti...

  13. 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

  14. Creating prescription maps from historical imagery for site-specific management of cotton root rot

    Science.gov (United States)

    Cotton root rot, caused by the soilborne fungus Phymatotrichopsis omnivore, is a severe plant disease that has affected cotton production for over a century. Recent research found that a commercial fungicide, Topguard (flutriafol), was able to control this disease. As a result, Topguard Terra Fungic...

  15. 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...

  16. Rhizoctonia crown and root rot resistance evaluation of Beta PIs in Fort Collins, CO, 2015

    Science.gov (United States)

    Thirty beet accessions of either cultivated beet or sea beet (Beta vulgaris subsp. vulgaris or Beta vulgaris subsp. maritima (L.) Arcang) from the Beta collection of the USDA-Agricultural Research Service National Plant Germplasm System were screened for resistance to Rhizoctonia crown and root rot ...

  17. Rhizoctonia crown and root rot resistance evaluation of Beta PIs in Fort Collins, CO, 2014

    Science.gov (United States)

    Thirty-six sugar beet (Beta vulgaris subsp. vulgaris) germplasm from the USDA-Agricultural Research Service pre-breeding program at Fort Collins, Colorado were screened for resistance to Rhizoctonia crown and root rot (RCRR) at the Colorado State University ARDEC facility in Fort Collins, CO. There...

  18. Rhizoctonia root rot resistance of Beta PIs from the USDA-ARS NPGS, 2007.

    Science.gov (United States)

    Thirty-two plant introductions (PI) from the USDA-ARS National Plant Germplasm System (NPGS) (including garden beet, sugar beet, leaf beet, fodder beet, and wild beet) were evaluated for resistance to Rhizoctonia root rot. The trial was a randomized complete-block design with five replications in ...

  19. 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...

  20. Development of Phytophthora root rot-resistant avocado rootstocks for the Caribbean.

    Science.gov (United States)

    Phytophtora root rot (PRR), caused by Phytopthora cinnamoni Rands, poses the greatest limitation to avocado production worldwide. Through a collaborative effort between researchers at the USDA-ARS facility in Miami and the University of Florida in Homestead, PRR-resistant avocado rootstocks are bein...

  1. Mechanisms of biological control of Fusarium root and stem rot of greenhouse cucumber by Gliocladium catenulatum

    OpenAIRE

    Chatterton, Syama Gauri Dasi

    2010-01-01

    Gliocladium catenulatum strain J1446 (formulated as Prestop WP, Verdera Oy) is a biological control agent of Fusarium root and stem rot caused by Fusarium oxysporum f. sp. radicis-cucumerinum on greenhouse cucumber plants. The mechanisms involved in biocontrol efficacy are currently unknown. Following transformation of G. catenulatum with the ß-glucuronidase (uidA) gene, blue-stained mycelia could be seen growing on the surface and within epidermal and cortical cells of roots, stems and shoot...

  2. 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.

  3. Fusarium species from the cassava root rot complex in west Africa.

    Science.gov (United States)

    Bandyopadhyay, Ranajit; Mwangi, Maina; Aigbe, Sylvester O; Leslie, John F

    2006-06-01

    ABSTRACT Fusarium species are a significant component of the set of fungi associated with cassava root rot. Yield losses due to root rot average 0.5 to 1 ton/ha but losses >3 ton/ha, an equivalent of 15 to 20% yield, often occur. This paper reviews previous work on cassava root rot and summarizes a few recent studies on Fusarium species associated with the disease. Our studies in Cameroon showed that 30% of rotted tubers were infected by Fusarium spp. 12 months after planting and represented 25% of all the fungal isolates recovered. Other commonly recovered fungi were Botryodiplodia theobromae and Armillaria spp. Numerous and diverse species of Fusarium were associated with rotted cassava roots in Nigeria and Cameroon. At least 13 distinct amplified fragment length polymorphism (AFLP) groups of Fusarium were distinguishable, each group probably a distinct species, and many of them might represent previously undescribed Fusarium species. The two largest of the AFLP groups correspond to F. oxysporum and F. solani species complex. The distribution of Fusarium spp. varied among countries and among locations within a country, suggesting that germ plasm resistant at one location may not be resistant at another. Fusarium spp. also cause seedling blight of cassava and can be recovered from the stems of infected plants up to 1 m above the ground. Therefore, the pathogen can spread with stems cut as planting material. Fusarium spp. also can colonize Chromolaena odorata, the dominant weed in short fallows, which could further complicate management efforts by serving as an alternative host for strains that colonize cassava. PMID:18943189

  4. A DNA based method to detect the grapevine root-rotting fungus Roesleria subterranea in soil and root samples

    OpenAIRE

    Neuhauser, Sigrid; Huber, Lars; Kirchmair, Martin

    2009-01-01

    Roesleria subterranea causes root rot in grapevine and fruit trees. The fungus has long been underestimated as a weak parasite, but during the last years it has been reported to cause severe damages in German vineyards. Direct, observation-based detection of the parasite is time consuming and destructive, as large parts of the rootstocks have to be uprooted and screened for the tiny, stipitate, hypogeous ascomata of R. subterranea. To facilitate rapid detection in vineyards, protocols to extr...

  5. 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.

  6. Wide Variation in Virulence and Genetic Diversity of Binucleate Rhizoctonia Isolates Associated with Root Rot of Strawberry in Western Australia

    OpenAIRE

    Xiangling Fang; 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 ...

  7. MANAGEMENT OF ROOT ROT DISEASE [MACROPHOMINA PHASEOLINA (TASSI. GOID] OF CHICKPEA THROUGH BOTANICALS AND OIL CAKES

    Directory of Open Access Journals (Sweden)

    S. S. KANSARA

    2013-01-01

    Full Text Available Occurrence of root rot disease in chickpea has become a major constraint for cultivation of chickpea. Consideringthe fact, below investigation was carried out for this pathological problem. The efficacy of various botanicals andoil cakes were evaluated against Macrophomina phaseolina (Tassi. Goid causing dry root rot of chickpea. Thephyto extracts of thirteen plant species were evaluated in vitro by poisoned food technique against M. phaseolina.The extract of garlic cloves (Allium sativum L. was proved excellent with maximum inhibiting (73 % mycelialgrowth and sclerotial formation followed by rhizome extract of turmeric (Curcuma longa L (63.98 %. The fourorganic extracts were tested against M. phaseolina by poisoned food technique in vitro. Significantly least growthof mycelium and maximum mycelium inhibition was recorded in extracts of neem cake (59.40 % followed byfarm yard manure (42.56 %. Next best in order of merit were castor cake and mustard cake.

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

    OpenAIRE

    Hassan, Naglaa; Shimizu, Masafumi; Hyakumachi, Mitsuro

    2014-01-01

    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 wit...

  9. 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.

  10. 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. PMID:25606010

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. Use of homeopathic drugs in combination with fertilizers for the control of root rot fungi

    International Nuclear Information System (INIS)

    This study was conducted to evaluate the fungicidal effectiveness of homeopathic drugs in combination with fertilizers on the growth production and controlling of root rot fungi. Seeds treated with homeopathic drugs in addition of phosphorous and nitrogen fertilizers as soil amendment showed significant inhibitory effect on fungal growth as well as improved the plant growth. Remarkable control of root infecting fungi was shown by the seeds treated with Thuja occidentalis and Arnica montana at rate of 75 percentage v/v concentration and soil amended with urea at rate of 0.1 percentage w/w but greater increased in plant growth was observed by urea at rate of 0.01 percentage in the tested plants viz. mung bean, mash bean, sunflower and okra. Whereas, when A. montana and T. occidentalis at rate of 75 percentage v/v concentration along with the addition of DAP at rate of 0.01 and 0.1 percentage w/w respectively showed maximum suppression of Fusarium spp, R. solani and M. phaseolina and enhanced the plant height and weight followed by A. montana and T. occidentalis at rate of 50 percentage v/v concentration respectively showed a maximum control of root rot fungi and also strengthened the crop plant for better growth. (author)

  17. Irradiation seed treatment reduces scald, common root rot and increases phosphorus absorption of barley

    International Nuclear Information System (INIS)

    The effect of low doses of gamma irradiation on severity of barley to scald and common root rot diseases, and phosphorus absorption was studied seeds were exposed to doses of 0, 10, 15, 20, 30, 40 and 50 Gy. A stimulatory effect was observed at irradiation doses of 30 and 40 Gy, which decreased the severity of barley to scald by 34% and 31% respectively. On the other hand, doses 20 and 30 Gy decreased the severity to CRR by 54% and 49% respectively, whereas, phosphorus absorption was significantly increased at doses of 15 and 20 Gy

  18. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  20. IMPROVMENT BIOCONTROL OF DAMPING-OFF AND ROOT ROT/WILT OF FABA BEAN BY SALICYLIC ACID AND HYDROGEN PEROXIDE

    OpenAIRE

    Montaser F. Abdel-Monaim

    2013-01-01

    Rhizoctonia solani, Fusarium solani, F. oxysporum and Macrophomina phaseolina were found to be associated with root rot and wilt symptoms of faba bean plants collected from different fields 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 pathogenici...

  1. 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

  2. Biological control of Rhizoctonia root rot on bean by phenazine- and cyclic lipopeptide-producing Pseudomonas CMR12a

    Science.gov (United States)

    Pseudomonas CMR12a was previously selected as an efficient biocontrol strain producing phenazines and cyclic lipopeptides (CLPs). In this study, biocontrol capacity of Pseudomonas CMR12a against Rhizoctonia root rot of bean and the involvement of phenazines and CLPs in this ability were tested. Two ...

  3. 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

  4. Using airborne multispectral imagery to monitor cotton root rot progression in fungicide-treated and non-treated cotton fields

    Science.gov (United States)

    Cotton root rot has affected cotton production in the southwestern and south central U.S for over 100 years. A fungicide, flutriafol, has shown considerable promise for controlling this disease in field studies in the last few years. With the temporary authorization for use of the fungicide to contr...

  5. 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...

  6. 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...

  7. Sugar beet breeding lines evaluated for resistance to Rhizoctonia crown and root rot in Fort Collins, CO, 2015

    Science.gov (United States)

    Thirty-nine beet sugar beet breeding lines (Beta vulgaris subsp. vulgaris) from the USDA-Agricultural Research Service breeding program at Fort Collins, CO, were screened for resistance to Rhizoctonia crown and root rot (Rcrr) at the Colorado State University ARDEC facility in Fort Collins, CO. The...

  8. USDA-ARS germplasm evaluated for resistance to Rhizoctonia crown and root rot in Fort Collins, CO, 2014

    Science.gov (United States)

    Thirty-six sugar beet (Beta vulgaris subsp. vulgaris) germplasm from the USDA-Agricultural Research Service pre-breeding program at Fort Collins, Colorado were screened for resistance to Rhizoctonia crown and root rot (RCRR) at the Colorado State University ARDEC facility in Fort Collins, CO. There...

  9. 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) ...

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Improved horticultural practices against leaf wilting, root rot and nutrient uptake in mango (mangiferaindica l.)

    International Nuclear Information System (INIS)

    Poor plant health condition due to various known biotic and abiotic stresses; becoming a disaster in each mango growing country of the world including Pakistan. On the basis of previous researches on the identification of pathogen and several abiotic factors; Soil drenching and foliar spray of various concentrations of Topsin M (TMIC), Aliette (ATP) and Ridomil Gold (ACE) in combination with CuSO/sub 4/(Copper sulphate) was done on mango plants of cv. S.B. (Samar Bahist) Chaunsa showing wilting of leaves and shoots. Foliar application of micro-nutrients (Fe, B and Zn) (Iron, Boron and Zinc) was also practiced to improve general health of experimental plants Month-wise emergence of flushes was significantly higher in all treated plants compared with control. Percentage of wilted leaves and root rot in plants, which received drenching and foliar treatments, was significantly reduced (50%) compared with untreated plants. Nitrogen, phosphorus and potassium (N, P and K) levels in leaves were significantly improved in treated plants compared with control. Sigmoid relatioship was observed between fungicides and copper sulphate concentrations and uptake of N, P and K in treated plants. Application of 250g ATP fungicide by foliar spray plus 125g by soil drench, each along with 50g CuSO/sub 4/proved to be the best against leaf wilting and it improved the N and P level in leaves. While, application of 250g TMIC by foliar spray and 125g by soil drench, each with 50g CuSO/sub 4/, was found to be the best to reduce the spread of root rot in experimental plants. Preliminary spray of TMIC along with Copper sulphate is effective to improve plant health of mango cv. S.B. Chounsa. (author)

  13. Development of a DNA Microarray-Based Assay for the Detection of Sugar Beet Root Rot Pathogens.

    Science.gov (United States)

    Liebe, Sebastian; Christ, Daniela S; Ehricht, Ralf; Varrelmann, Mark

    2016-01-01

    Sugar beet root rot diseases that occur during the cropping season or in storage are accompanied by high yield losses and a severe reduction of processing quality. The vast diversity of microorganism species involved in rot development requires molecular tools allowing simultaneous identification of many different targets. Therefore, a new microarray technology (ArrayTube) was applied in this study to improve diagnosis of sugar beet root rot diseases. Based on three marker genes (internal transcribed spacer, translation elongation factor 1 alpha, and 16S ribosomal DNA), 42 well-performing probes enabled the identification of prevalent field pathogens (e.g., Aphanomyces cochlioides), storage pathogens (e.g., Botrytis cinerea), and ubiquitous spoilage fungi (e.g., Penicillium expansum). All probes were proven for specificity with pure cultures from 73 microorganism species as well as for in planta detection of their target species using inoculated sugar beet tissue. Microarray-based identification of root rot pathogens in diseased field beets was successfully confirmed by classical detection methods. The high discriminatory potential was proven by Fusarium species differentiation based on a single nucleotide polymorphism. The results demonstrate that the ArrayTube constitute an innovative tool allowing a rapid and reliable detection of plant pathogens particularly when multiple microorganism species are present. PMID:26524545

  14. Effect of (/sup 60/cobalt) gamma rays on growth and root rot diseases in mungbean (vigna radiata L.)

    International Nuclear Information System (INIS)

    Present investigation showed that gamma rays influences suppressive effect on root rot fungi such as Macrophomina phaseolina (Tassi) Goid, Rhizoctonia solani Kuhn and Fusarium spp., and inducive effect on growth parameters of mung bean (Vigna radiata L.). Seeds of mung bean were treated with gamma rays (/sup 60/Cobalt) at time periods of 0 and 4 minutes and stored for 90 days at room temperature to determine its effect on growth parameters and infection of root infecting fungi. All treatments of gamma rays enhanced the growth parameters as compared to untreated plants. Infection of M. phaseolina, R. solani and Fusarium spp., were significantly decreased on mung bean seeds treated with gamma rays. Gamma rays significantly increased the growth parameters and controlled the root rot fungi up to 90 days of storage of seeds. (author)

  15. Somaclonal variation of sugar beet resistant to pathogenic root rot Fusarium oxysporum var. orthoceras

    Directory of Open Access Journals (Sweden)

    Urazaliev Kairat

    2013-01-01

    Full Text Available Sugar beet (Beta vulgaris L. - one of the most important crop in the world. In Kazakhstan, it is a traditional and major source of domestic sugar. The industry of cultivation and production of sugar beet is one of the priority areas of agricultural development of the country. In this paper, we studied the regeneration ability of different genotypes of sugar beet explants on selective media with the culture filtrate of the pathogen fungus F. oxysporum var. orthoceras. From the roots and shoots of sugar beet the pathogen Fusarium root rot was isolated. Was obtained pure cultures of the isolated pathogen. As a result, of morphological and cultural descriptions, as well as microbiological analysis it was revealed that the isolated pathogen is Fusarium Oxysporum. The results showed the pathogenicity of the fungus. For regeneration in vitro of the sugar beet genotypes resistant to the pathogen the culture media was optimized to the culture filtrate of the fungus F. oxysporum var. orthoceras. The frequency of shoot regeneration, depending on the genotype, was 1,0-12,5 %. On these explants the multiple shoot formations were observed.

  16. Incidence of root and butt rot in consecutive rotations, with emphasis on Heterobasidion annosum in Norway spruce

    Energy Technology Data Exchange (ETDEWEB)

    Roennberg, J. [Swedish Univ. of Agricultural Sciences, Alnarp (Sweden). Southern Swedish Forest Research Centre

    1999-06-01

    The incidence of root and butt rot in consecutive rotations was evaluated in five separate studies. The susceptibility to infections by Heterobasidion annosum was examined in a 28-year-old tree species experiment in northern Jutland, Denmark, established after a heavily infected mountain pine (Pinus uncinata) stand. Pseudotsuga menziesii and Abies nobilis showed greatest mortality due to H. annosum within five years of planting. The highest incidences of butt rot at first thinning, mainly caused by H. annosum of the P-group, were recorded in A. nobilis, Larix leptolepis and Picea sitchensis, with 44 %, 43 % and 36 % of the thinned trees infected respectively. Abies alba and A. nordmanniana were almost free from infections. The incidence of H. annosum was examined in three young hybrid larch (Larix x eurolepis) plantations in southern Sweden established after heavily infected Picea abies stands. The incidence of H. annosum was 7 %, 33 %, and 70 % respectively, in the 2-, 3-, and 5-year-old plantations. Transfer of H. annosum from infected old P. abies stumps to hybrid larch occurs early after planting. The incidence of butt rot in two consecutive rotations in 28 permanent sample plots of P. abies at four different sites in Denmark and at six plots in southwestern Sweden was evaluated. No correlation between the incidence of butt rot at final felling of the previous rotation of P. abies and the incidence of butt rot at first thinning of the subsequent rotation of P. abies was found. In two studies the effects of clear felling operations on stump root damage to P. abies were examined. Numerous cases of damage on stumps and roots were found. However, few cases of damage get infected by spores of H. annosum, and treatment of clear felled P. abies stumps may be a way of reducing the possible infection source transferring the infection of H. annosum to the subsequent rotation 173 refs, 1 fig

  17. 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.

  18. Control of root rot of chickpea caused by Sclerotium rolfsii by different agents and gamma radiation

    International Nuclear Information System (INIS)

    Sclerotium rolfsii causes root rot disease in several crops including chickpea that result in low yield. Artificial infection of chickpea seedlings by S. rolfsii in vitro demonstrated that different tissues of the plant completely disintegrated by fungal infection. In vitro and green house pot experiments demonstrated that inducers in combination with fungicides, oils and bio agents resulted in about 80 % suppression of root rot disease. Treatments have no phyto toxic effect on chickpea seedlings at low doses. Gliocladium virens and Gliocladium deliquescens were effective as biocontrol agents against Sclerotium rolfsii. The percent of survival plants, fresh weight, dry weight and plant height of chickpea plants increased with different treatments with inducers compared with the control. Chlorophyll a, b, and total chlorophyll amounts increased to the maximum values. The activity of two plant enzymes, peroxidase and polyphenol oxidase increased. In this study, gamma irradiation of chickpea seeds at doses 5, 10, 15, 20, 25 and 30 Gy have negative effect on survival, plant height, fresh weight and dry weight of chickpea. The effect of gamma irradiation at doses 0.25, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 kGy on the antagonistic effect of Gliocladium virens and Gliocladium deliquescens against S. rolfsii were investigated. The results revealed that gamma irradiation increase the antagonistic effect of Gliocladium virens and Gliocladium deliquescens against S. rolfsii . Effect of gamma irradiation at doses of 0, 0.25, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0 and 5 kGy on the mycelial growth and pathogenicity of S. rolfsii were investigated. The results revealed that gamma irradiation at doses 0.25 up to 3.0 kGy increase the pathogenicity of S. rolfsii but gamma irradiation at dose 5.0 kGy completely inhibited the growth of S. rolfsii. Extracellular polygalacturonase was characterized and purified by precipitation with 70 % ammonium sulfate, dialysis and gel filtration through Sephadex 75

  19. Reaction of selected soybean cultivars to Rhizoctonia root rot and other damping-off disease agents.

    Science.gov (United States)

    Amer, M A

    2005-01-01

    Eight soybean cultivars; Giza 21. Giza 22, Giza 35, Giza 82, Giza 83, Crawford, Holladay and Toamo were evaluated to Rhizoctonia root rot using agar plate and potted plant techniques. Data cleared that, in agar plate assay all soybean cultivars were moderately susceptible (MS), although the differences between them were significant (P=0.05). Generally, in potted assay, the reactions were resistant (R) or moderately resistant (MR) to root rots. Also, the differences between cultivars were significant (P=0.05). These cultivars were inoculated under greenhouse conditions with Fusarium solani, Macrophomina phaseolina, Rhizoctonia solani and Sclerotium rolfsii Generally, G21 had the least pre-emergence damping-off followed by Giza 35, Crawford and Giza 83 with averages of 19.0, 20.0, 20.5 and 21.5%, respectively. In case of post-emergence, Giza 35 had the least values, followed by Giza 21, Crawford and Giza 82 with averages 3.95, 4.10, 4.10 and 4.25%, respectively. Under naturally infested soil in the field conditions the reactions of the same cultivars to damping-off were evaluated in two successive seasons. In 2002 season, G35 had the least pre-emergence damping-off % followed by Giza 21 and Giza 22 with averages of 22.61, 24.33 and 29.33%, respectively. Also, G35 had the least post-emergence damping-off % followed by Toamo and Giza 21 with averages of 9.40, 10.33 and 10.41%, respectively. In 2003 season, the same trend was appeared with light grade where Giza 35 had the least pre-emergence damping of % followed by Giza 22 and Giza 21 with averages of 30.67, 31.00 and 36.67%, respectively and Giza 35 was the most resistant cultivar against post-emergence damping-off, followed by Giza 21 and Giza 22 with averages of 10.91, 11.32 and 11.80%, respectively. Generally, Giza 21 significantly surpassed the other cultivars in plant height, number of pods per plant and 100-seed weight. Moreover, also it had second grade with the other traits. PMID:16637203

  20. 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.

  1. 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.

  2. 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.

  3. 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. PMID:27490955

  4. 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. PMID:27490955

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

    Directory of Open Access Journals (Sweden)

    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.

  6. IMPROVMENT BIOCONTROL OF DAMPING-OFF AND ROOT ROT/WILT OF FABA BEAN BY SALICYLIC ACID AND HYDROGEN PEROXIDE

    Directory of Open Access Journals (Sweden)

    Montaser F. Abdel-Monaim

    2013-04-01

    Full Text Available Rhizoctonia solani, Fusarium solani, F. oxysporum and Macrophomina phaseolina were found to be associated with root rot and wilt symptoms of faba bean plants collected from different fields 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, Bacillus megaterium and chemical inducers (salicylic acid and hydrogen peroxide individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promotion 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 survival of plants. Also, these treatments increased fresh and dry weights of the survived plants in pots compared with control.  The combination of biocontrol agents and chemical inducers were more effective than using them individually and SA+ T. viride was the best treatment in this respect. Under field conditions, all these treatments significantly increased growth parameters (plant height and No. of branches plant-1 and yield components (No. of pods and seedsplant-1, weight of 100 seeds and total yield feddan-1 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 combination of biocontrol agents and

  7. Effect of Environment and Sugar Beet Genotype on Root Rot Development and Pathogen Profile During Storage.

    Science.gov (United States)

    Liebe, Sebastian; Varrelmann, Mark

    2016-01-01

    Storage rots represent an economically important factor impairing the storability of sugar beet by increasing sucrose losses and invert sugar content. Understanding the development of disease management strategies, knowledge about major storage pathogens, and factors influencing their occurrence is crucial. In comprehensive storage trials conducted under controlled conditions, the effects of environment and genotype on rot development and associated quality changes were investigated. Prevalent species involved in rot development were identified by a newly developed microarray. The strongest effect on rot development was assigned to environment factors followed by genotypic effects. Despite large variation in rot severity (sample range 0 to 84%), the spectrum of microorganisms colonizing sugar beet remained fairly constant across all treatments with dominant species belonging to the fungal genera Botrytis, Fusarium, and Penicillium. The intensity of microbial tissue necrotization was strongly correlated with sucrose losses (R² = 0.79 to 0.91) and invert sugar accumulation (R² = 0.91 to 0.95). A storage rot resistance bioassay was developed that could successfully reproduce the genotype ranking observed in storage trials. Quantification of fungal biomass indicates that genetic resistance is based on a quantitative mechanism. Further work is required to understand the large environmental influence on rot development in sugar beet. PMID:26474333

  8. 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.

  9. Biological Control of Pathogens Causing Root Rot Complex in Field Pea Using Clonostachys rosea Strain ACM941.

    Science.gov (United States)

    Xue, Allen G

    2003-03-01

    ABSTRACT Pea root rot complex (PRRC), caused by Alternaria alternata, Aphanomyces euteiches, Fusarium oxysporum f. sp. pisi, F. solani f. sp. pisi, Mycosphaerella pinodes, Pythium spp., Rhizoctonia solani, and Sclerotinia sclerotiorum, is a major yield-limiting factor for field pea production in Canada. A strain of Clonostachys rosea (syn. Gliocladium roseum), ACM941 (ATCC 74447), was identified as a mycoparasite against these pathogens. When grown near the pathogen, ACM941 often was stimulated to produce lateral branches that grew directly toward the pathogen mycelium, typically entwining around the pathogen mycelium. When applied to the seed, ACM941 propagated in the rhizosphere and colonized the seed coat, hypocotyl, and roots as the plant developed and grew. ACM941 significantly reduced the recovery of all fungal pathogens from infected seed, increased in vitro seed germination by 44% and seedling emergence by 22%, and reduced root rot severity by 76%. The effects were similar to those of thiram fungicide, which increased germination and emergence by 33 and 29%, respectively, and reduced root rot severity by 65%. When soil was inoculated with selected PRRC pathogens in a controlled environment, seed treatment with ACM941 significantly increased emergence by 26, 38, 28, 13, and 21% for F. oxysporum f. sp. pisi, F. solani f. sp. pisi, M. pinodes, R. solani, and S. sclerotiorum, respectively. Under field conditions from 1995 to 1997, ACM941 increased emergence by 17, 23, 22, 13, and 18% and yield by 15, 6, 28, 6, and 19% for the five respective pathogens. The seed treatment effects of ACM941 on these PRRC pathogens were greater or statistically equivalent to those achieved with thiram. Results of this study suggest that ACM941 is an effective bioagent in controlling PRRC and is an alternative to existing chemical products. PMID:18944343

  10. The root rot fungus Armillaria mellea introduced into South Africa by early Dutch settlers.

    Science.gov (United States)

    Coetzee, M P; Wingfield, B D; Harrington, T C; Steimel, J; Coutinho, T A; Wingfield, M J

    2001-02-01

    Dead and dying oak (Quercus) and numerous other woody ornamental trees and shrubs showing signs and symptoms of Armillaria root rot were identified in the Company Gardens, Cape Town, South Africa, which were established in the mid-1600s by the Dutch East Indies Trading Company. Nineteen isolates from dying trees or from mushrooms were collected and analysed to identify and characterize the Armillaria sp. responsible for the disease. The AluI digestion of the amplified product of the first intergenic spacer region (IGS-1) of the rRNA operon of 19 isolates from the Company Gardens was identical to that of some of the European isolates of A. mellea s. s. The IGS-1 region and the internal transcribed spacers (ITS) were sequenced for some of the Cape Town isolates. Phylogenetic analyses placed the Cape Town isolates in the European clade of A. mellea, which is distinct from the Asian and North American clades of this species. Identification based on sexual compatibility was conducted using A. mellea tester strains in diploid-haploid pairings, which showed some compatibility between the Cape Town isolates and testers from Europe. Somatic compatibility tests (diploid-diploid pairings) and DNA fingerprinting with multilocus, microsatellite probes indicated that the Cape Town isolates were genetically identical and may have resulted from vegetative (clonal) spread from a single focus in the centre of the original Company Gardens (c. 1652). The colonized area is at least 345 m in diameter. Assuming a linear spread rate underground of 0.3 m/year to 1.6 m/year, the genet (clone) was estimated to be between 108 and 575 years old. These data suggest that A. mellea was introduced into Cape Town from Europe, perhaps on potted plants, such as grapes or citrus, planted in the Company Gardens more than 300 years ago. PMID:11298953

  11. 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

  12. Bioagents and Commercial Algae Products as Integrated Biocide Treatments for Controlling Root Rot Diseases of Some Vegetables under Protected Cultivation System

    Directory of Open Access Journals (Sweden)

    Mokhtar M. Abdel-Kader

    2013-01-01

    Full Text Available Integrated commercial blue-green algae extracts and bioagents treatments against vegetables root rot incidence when used as soil drench under greenhouse and plastic house conditions were evaluated. All applied treatments reduced significantly root rot incidence at both pre- and postemergence growth stages of cucumber, cantaloupe, tomato, and pepper plants compared with untreated check control. In pot experiment, the obtained results showed that treatments of Trichoderma harzianum or Bacillus subtilis either alone or combined with commercial algae extracts were significantly superior for reducing root rot disease for two tested vegetable plants compared with the other tested treatments as well as control. It is also observed that rising concentrations of either algae products, Oligo-X or Weed-Max, were reflected in more disease reduction. Promising treatments for controlling root rot disease incidence were applied under plastic houses conditions. As for field trails carried out under plastic houses conditions at different locations, the obtained results revealed that the applied combined treatments significantly reduced root rot incidence compared with fungicide and check control treatments. At all locations it was observed that Weed-Max (2 g/L + Bacillus subtilis significantly reduced disease incidence of grown vegetables compared with Oligo-X (2 mL/L + Trichoderma harzianum treatments. An obvious yield increase in all treatments was significantly higher than in the control. Also, the harvested yield in applied combined treatments at all locations was significantly higher than that in the fungicide and control treatments.

  13. 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.

  14. 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.

  15. Conidioma production of the white root rot fungus [Rosellinia] in axenic culture under near-ultraviolet light radiation

    International Nuclear Information System (INIS)

    Conidiomata of the white root rot fungus were produced in axenic culture under near-ultraviolet light radiation. Pieces of sterilized Japanese pear twigs were placed on 7-day-old oatmeal agar culture in plates. The plates were further incubated for 5 days and then illuminated by near-ultraviolet light. Synnemata developed on the twigs within 5 weeks in 19 of 20 isolates tested, and conidia were observed in 12 of the 19 isolates. The synnemata and conidia produced were morphologically identical to those of Dematophora necatrix

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

    OpenAIRE

    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 stock plants. Any lot of such plants with even just a trace of the disease has to be destroyed. The plot on which the plants were harvested has to be abandoned for commercial strawberry propagation...

  17. 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.

  18. 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.

  19. Role of Antagonistic Microorganisms and Organic Amendment in Stimulating the Defense System of Okra Against Root Rotting Fungi.

    Science.gov (United States)

    Shafique, Hafiza Asma; Sultana, Viqar; Ara, Jehan; Ehteshamul-Haque, Syed; Athar, Mohammad

    2015-01-01

    Without application of chemical pesticides control of soilborne diseases is a great challenge. Stimulation of natural plant's defense is considered as one of the most promising alternative strategy for crop protection. Organic amendment of soil besides direct suppressing the pathogen, has been reported to have an influence on phytochemicals in plants. In the present study, Pseudomonas aeruginosa, a plant growth promoting rhizobacterium and Paecilomyces lilacinus, an egg parasite of root knot and cysts nematodes were examined individually and in combination in soil amended with cotton cake for suppressing the root rotting fungi and stimulating the synthesis of polyphenols and improving the antioxidant status in okra. Application of P. aeruginosa and P. lilacinus in soil amended with cotton cake significantly (P Rhizoctonia solani. Combine use of biocontrol agents in cotton cake amended soil showed maximum positive impact on plant growth, polyphenol concentration and antioxidant activity in okra. PMID:26373176

  20. 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.

  1. Rhizoctonia Crown and Root Rot Resistance of Beta Plant Introductions from the USDA, Agricultural Research Service's National Plant Germplasm System, 2010

    Science.gov (United States)

    Thirty wild beet (Beta vulgaris subsp. maritima (L.) Arcang) plant introduction (PI) accessions from the Beta collection of the USDA-ARS National Plant Germplasm System were screened for resistance to Rhizoctonia root and crown rot, at the USDA-ARS Fort Collins, CO Research Farm. The Rhizoctonia sc...

  2. 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 reduci...

  3. Effects of silvicultural practices on the incidence of root and butt rot in Norway spruce with special emphasis on Heterobasidion annosum

    Energy Technology Data Exchange (ETDEWEB)

    Vollbrecht, G.

    1994-01-01

    The results from six separate studies investigating the effects of silvicultural practices on the incidence of root and butt rot in Norway spruce (Picea abies (L.) Karst.), are summarized and discussed. Norway spruce, planted in a site where the previous generation consisted of Norway spruce heavily infected by Heterobasidion annosum (Fr.) Bref., was attacked less by H. annosum than were European larch (Larix decidua Mill.) Japanese larch (Larix kaempferi (Lamb.) Carr.) or Sitka spruce (Picea sitchensis (Bong.) Carr.). Scots pine (Pinus sylvestris L.) exhibited the least damage from butt rot. In a pre-commercial thinning experiment involving young planted Norway spruce, no residual trees were found to be infected by H. annosum as a result of the thinning. It is concluded that control measures to prevent stump surface infection of H. annosum do not seem necessary when pre-commercial thinning is carried out in young planted Norway spruce. The initial effects of late, heavy pre-commercial thinning in 19 year old Norway spruce on the incidence of butt root, storm damage and stem and branch thickness were studied. Forest management including pre-commercial thinning resulted in more storm damage, greater height of the rot column and greater branch and stem thickness than forest management without pre-commercial thinning. The incidence of butt rot in uprooted trees was 4-5 times greater than in residual trees, which emphasizes the importance of root and butt rot when assessing the hazard of windthrow. Two empirical models to forecast the incidence of butt rot at stand level, one for southern Sweden and one for Denmark, are presented. 120 refs, 3 figs, 1 tab

  4. 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.

  5. 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

  6. Pathogenicity of some Rhizoctonia solaniz isolates associated with root/collar rots on the cultivars of bean in greenhouse.

    Science.gov (United States)

    Bohlooli, A; Okhovvat, S M; Javan-Nikkhah, M

    2006-01-01

    One hundred and eighteen isolates of Rhizoctonia solani were gathered from infected roots and hypocotyls of bean (Phaseolus vulgaris L.) grown in the fields of Tehran Province, Iran. Two isolates of the collected samples belonged to binucleate and 81 isolates to multinucleate of R. solani. The multinucleate isolates showed different anastomosis groups as AG-4 (subg. AG-4 HGI, AG-4HGII), AG-6 and AG-2. In greenhouse, pathogenicity tests carried out on bean cv. Naz in randomized design with 4 replications and each replication (pots) with 5 seeds of bean. Infection was done with seeds of wheat which were infected to the fungus with pasteurized soil. Results showed that the highest disease severity was caused by AG-4 (Rs21) isolates, whereas AG-4 (Rs74) isolates were weakly pathogenic with 90% and 21% infection, respectively. In this test the major pathogenic isolates belonged to AG-4 and they caused seed rot and damping-off of bean and AG-6 isolates were non-pathogenic. Five isolates of the fungus with major pathogenicity (Rs7, Rs18, Rs21, Rs62 and Rs71) selected and used for the reaction with different cultivars of bean. In this test, the cultivars and lines of bean (Pinto, red, white, green) studied in factorial experiment as randomized block design with 4 replications (pots). Results showed that none of the cultivars was completely resistant, however green bean cv. Sanry and pinto cv. Shad with number 4.8 disease severities had the highest susceptibility to seed rot and damping-off and red bean cv. Goli with 2.58 had the lowest susceptibility to the infection. Reaction of the cultivars and lines to the isolates of R. solani was significantly different at 1% level. Isolates of the fungus, Rs7, Rs21 with 84%, 90% pathogenicity was more virulent than the others. PMID:17390878

  7. 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.

  8. Management of root rot and root knot disease of mungbean with the application of mycorrhizospheric fluorescent pseudomonas under field condition

    International Nuclear Information System (INIS)

    The mycorrhizosphere is the region around a mycorrhizal fungus in which nutrients released from the hyphae increases microbial population and its activities. In this study five mycorrhizospheric fluorescent Pseudomonas (MRFP) were evaluated for biocontrol potential under field condition using mungbean (Vigna radiata) as test plant. MRFP-249 significantly reduced Fusarium solani, Rhizoctonia solani and Macrophomina phaseolina. Whereas MRFP246 and MRFP-247 were also found effective against M. phaseolina. Mycorrhizospheric fluorescent Pseudomonas were also found effective against root knot nematode by reducing the galls on roots and nematode's penetration in roots. Highest fresh shoot weight and plant height was produced by MRFP-248. Plants grown in soil treated with Pseudomonas showed higher number of VAM spores around the mungbean roots than untreated control plants. The mycorrhizal symbiosis should not be considered merely as bipartite, plant-fungus interaction, but should instead include the associated microorganisms, particularly fluorescent Pseudomonas. (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. 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

    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 )。%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.

  11. 大豆疫霉根腐病的几种实验室检验方法%Several Lab. Quarantine Methods of Soybean Phytophthora Root Rot

    Institute of Scientific and Technical Information of China (English)

    肖迪; 葛红霞; 肖威

    2006-01-01

    大豆疫霉根腐病(Soybean Phytophthora Root Rot)是我国一类检疫对象.近年,大豆疫霉根腐病的检验技术研究也相继开展起来,本文综述了大豆疫霉根腐病的土壤检测、病植检测、种子检测等几种实验室检测方法.

  12. The Effects of Arbuscular Mycorrhizal Fungus (AMF) and Humic Acid on the Growth of Pepper (Capsicum annuum L.) Plant and Root Rot Disease Caused by Phytophthora capsici Leonian

    OpenAIRE

    ASLANPAY, Burcu; Semra DEMİR

    2015-01-01

    In this study, the effects of singular and double combinations of Arbuscular Mycorrhizal Fungi (AMF) and humic acid (HA) were investigated on the growth of pepper (Capsicum annuum L.) and rot root disease caused by Phytophthora capsici Leonian which has been known as an important problem of pepper cultivation and leading yield losses. Under controlled conditions, four F1 pepper cultivars (Ergenekon, Bafra, Sirena and Yıldız) were inoculated with three different AMF strains (Glomus intraradice...

  13. 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...... resources, application of PRD irrigation could be a promising approach for saving water and for preventing BER development in tomatoes....

  14. 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

  15. Differential Responses of Vanilla Accessions to Root Rot and Colonization by Fusarium oxysporum f. sp. radicis-vanillae.

    Science.gov (United States)

    Koyyappurath, Sayuj; Conéjéro, Geneviève; Dijoux, Jean Bernard; Lapeyre-Montès, Fabienne; Jade, Katia; Chiroleu, Frédéric; Gatineau, Frédéric; Verdeil, Jean Luc; Besse, Pascale; Grisoni, Michel

    2015-01-01

    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 accessions

  16. Differential Responses of Vanilla Accessions to Root Rot and Colonization by Fusarium oxysporum f. sp. radicis-vanillae.

    Science.gov (United States)

    Koyyappurath, Sayuj; Conéjéro, Geneviève; Dijoux, Jean Bernard; Lapeyre-Montès, Fabienne; Jade, Katia; Chiroleu, Frédéric; Gatineau, Frédéric; Verdeil, Jean Luc; Besse, Pascale; Grisoni, Michel

    2015-01-01

    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 accessions

  17. A Colletotrichum sp. causing root rot in sugar beet (Beta vulgaris)

    Science.gov (United States)

    In fall of 2014 sugar beets were observed in a field in Washington State with shallow, dark, firm lesions on the surface. When examined under magnification, minute black “dots” were observed on the surface of the lesions. Isolations were made from the lesions and a Colletotrichum species was consist...

  18. 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...

  19. First report of root rot of Chicory caused by Phytophthora cryptogea in Chile

    Science.gov (United States)

    Chicory (Cichorium intybus L. var sativum Bisch.), a relatively new high value crop in Chile, was introduced for commercial production of inulin. Inulins are polysaccharides extracted from chicory tap roots that are used in processed foods due to their beneficial gastrointestinal properties. Approxi...

  20. 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.

  1. 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.

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

    OpenAIRE

    Montaser Fawzy ABDEL-MONAIM

    2013-01-01

    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 pathogen...

  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. Seed priming with extracts of Acacia nilotica (L.) Willd. ex Delile and Sapindus mukorossi (L.) plant parts in the control of root rot fungi and growth of plants

    International Nuclear Information System (INIS)

    Seed priming with plant extracts and chemicals has been used as an important growth enhancement tool in crop plants. In this research, an attempt was made to understand the mechanism of various seed priming treatments on greenhouse-grown okra (Abelmoschus esculentus (L.) Moench.), sunflower (Helianthus annuus L.), peanut (Arachis hypogaea L.) and chickpea (Cicer arietinum L.) for the control of root infecting fungi like Rhizoctonia solani (Kn), Fusarium spp. and Macrophomina phaseolina (Tassi) Goid by plant parts extracts (stem, leaves and seeds) of Acacia nilotica (L.) Willd. ex Delile and Sapindus mukorossi (L) at different time intervals (5, 10, 20, 40 minutes). Results showed significant suppression of root rot fungi and significantly enhanced the growth parameters like shoot length, root length, shoot weight and root weight. Seed-priming with A. nilotica and S. mukorossi leaves extract for 10 minutes time interval was found to be effective for the control of root rot fungi and growth of all tested leguminous and non-leguminous plants. (author)

  5. 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.

  6. EFFECT OF SHADING ON INCIDENCE OF BLACK ROT DISEASE AND YIELD QUALITY OF BROCCOLI IN HUMID TROPICAL REGIONS OF THAILAND

    Directory of Open Access Journals (Sweden)

    Karistsapol Nooprom

    2013-08-01

    Full Text Available The study was carried out in the experimental location of Department of Plant Science, Faculty of Natural Resources, Prince of Songkla University, Thailand, from April to June, 2012. Split-plot in randomized complete block design was used in this experiment with four replications. The broccoli plants under the shading had the lowest incidence of black rot disease (14.48% which was significantly lower than the full sunlight (76.91%. There was a positive impact of the shading on yield quality of the broccoli. The Yok Kheo had the highest head length and diameter (39.13 cm and 12.11 cm, respectively when planting under the shading. These results consistent with broccoli total yield, the highest total yield was obtained from the Yok Kheo under the both shading and full sunlight (10.92 t.ha-1 and 8.29 t.ha-1, respectively, followed by the Green Queen under the shading (6.21 t.ha-1. Therefore, the appropriate variety for planting during dry season in humid tropical regions of Thailand was the Yok Kheo and Green Queen because its total yield per hectare was higher than of the Top Green and they also had higher quality of head.

  7. Effect of inoculum density and soil tillage on the development and severity of rhizoctonia root rot.

    Science.gov (United States)

    Schroeder, K L; Paulitz, T C

    2008-03-01

    Rhizoctonia spp. cause substantial yield losses in direct-seeded cereal crops compared with conventional tillage. To investigate the mechanisms behind this increased disease, soils from tilled or direct-seeded fields were inoculated with Rhizoctonia spp. at population densities from 0.8 to 250 propagules per gram and planted with barley (Hordeum vulgare). The incidence and severity of disease did not differ between soils with different tillage histories. Both R. solani AG-8 and R. oryzae stunted plants at high inoculum densities, with the latter causing pre-emergence damping-off. High inoculum densities of both species stimulated early production of crown roots in barley seedlings. Intact soil cores from these same tilled and direct-seeded fields were used to evaluate the growth of Rhizoctonia spp. from colonized oat seeds. Growth of R. oryzae was not affected by previous tillage history. However, R. solani AG-8 grew more rapidly through soil from a long-term direct-seeded field compared to tilled soils. The differential response between these two experiments (mixed, homogenized soil versus intact soil) suggests that soil structure plays a major role in the proliferation of R. solani AG-8 through soils with different tillage histories. PMID:18944081

  8. 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

  9. FcStuA from Fusarium culmorum controls wheat foot and root rot in a toxin dispensable manner.

    Directory of Open Access Journals (Sweden)

    Matias Pasquali

    Full Text Available Fusarium culmorum is one of the most harmful pathogens of durum wheat and is the causal agent of foot and root rot (FRR disease. F. culmorum produces the mycotoxin deoxynivalenol (DON that is involved in the pathogenic process. The role of the gene FcStuA, a StuA ortholog protein with an APSES domain sharing 98.5% homology to the FgStuA protein (FGSG10129, was determined by functional characterisation of deletion mutants obtained from two F. culmorum wild-type strains, FcUk99 (a highly pathogenic DON producer and Fc233B (unable to produce toxin and with a mild pathogenic behavior. The ΔFcStuA mutants originating from both strains showed common phenotypic characters including stunted vegetative growth, loss of hydrophobicity of the mycelium, altered pigmentation, decreased activity of polygalacturonic enzymes and catalases, altered and reduced conidiation, delayed conidial germination patterns and complete loss of pathogenicity towards wheat stem base/root tissue. Glycolytic process efficiency [measured as growth on glucose as sole carbon (C source] was strongly impaired and growth was partially restored on glutamic acid. Growth on pectin-like sources ranked in between glucose and glutamic acid with the following order (the lowest to the highest growth: beechwood xylan, sugarbeet arabinan, polygalacturonic acid, citrus pectin, apple pectin, potato azogalactan. DON production in the mutants originating from FcUK99 strain was significantly decreased (-95% in vitro. Moreover, both sets of mutants were unable to colonise non-cereal plant tissues, i.e. apple and tomato fruits and potato tubers. No differences between mutants, ectopic and wild-type strains were observed concerning the level of resistance towards four fungicides belonging to three classes, the demethylase inhibitors epoxiconazole and tebuconzole, the succinate dehydrogenase inhibitor isopyrazam and the cytochrome bc1 inhibitor trifloxystrobin. StuA, given its multiple functions in cell

  10. 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.

  11. 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.

  12. 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

  13. Modeling Lolium perenne L. roots in the presence of empirical black holes

    Science.gov (United States)

    Plant root models are designed for understanding structural or functional aspects of root systems. When a process is not thoroughly understood, a black box object is used. However, when a process exists but empirical data do not indicate its existence, you have a black hole. The object of this re...

  14. Microbial Properties of Composts That Suppress Damping-Off and Root Rot of Creeping Bentgrass Caused by Pythium graminicola.

    Science.gov (United States)

    Craft, C M; Nelson, E B

    1996-05-01

    pressure was high (i.e., disease ratings high in uninoculated plots). A 1991 batch of turkey litter compost and the 1990 batch of Endicott biosolids were consistently suppressive to foliar symptoms of Pythium root rot on creeping bentgrass. This study indicates that suppression of Pythium diseases of creeping bentgrass in batches of brewery sludge and Endicott biosolids composts, and possibly in other suppressive composts examined in less detail in this study, is related directly to the microbial activities in the composts. On the other hand, the mechanisms of Pythium suppression in turkey litter and perhaps other poultry-based composts is not related directly to the compost microbial activity. Although turkey litter showed a lack of suppressiveness in laboratory bioassays and low microbial populations and activity, it resulted in a significant and consistent level of suppressiveness in field experiments. Therefore, the microbiological properties of Pythium-suppressive composts may differ substantially, and measurements of microbial populations and activity may not be predictive of the level of disease suppression in all composts. PMID:16535307

  15. Nutrient Dynamics of Fine Roots in the Mixed Plantation of Poplar and Black Locust

    Institute of Scientific and Technical Information of China (English)

    Zhai Mingpu; Jiang Sannai; Jia Liming

    2006-01-01

    The mixed plantation of poplar (Populus spp.)and black locust (Robinia pseudoacacia) is one of the typical mixed stands with nitrogen-fixing and non-nitrogen-fixing species.Interaction between the two species in the mixed stand is harmonious and productivity is high,making this kind of mixed plantation a very successful pattern on poor sandy sites in north China.In this study,the fine root decomposition of the two species was investigated in the mixed plantation of 27-year-old Canadian poplar (P.canadansis)and 22-year-old black locust on sandy sites along the Chaobai River in Beijing.Mechanism of harmonious interaction between the two species was observed in the view of the nutrient cycle of fine roots.Results showed that:(1) the fine root decomposition of Canadian poplar and black locust trees was different.Concentrations of N,Ca and Mg gradually increased and those of P and K gradually decreased in the fine roots of poplar during the period of decomposition.Concentrations of N,P and K gradually decreased in the fine roots of black locust during decomposition.The speed of nutrient decomposition in mixed fine roots of the two species fell between the speed of the two pure samples.(2) During decomposition,the annual return amount of N,K and Mg in fine roots of black locust was highest,followed by the mixed fine roots of the two species,and then the fine roots of poplar.(3) The increased return amount of N in mixed fine roots could improve the N nutrient condition of poplar trees.The return amount of P in poplar Fine roots was greater than that of black locust,which could improve the P nutrient of black locust trees.The interaction of mutual supplements of N and P nutrient cycle of fine roots between these two species formed.

  16. 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.

  17. 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.

  18. WEED PLANTS OF THE FAMILY POACEAE AS SOURCES OF INFECTION OF WINTER WHEAT ROOT ROT Сорные растения семейства poaceae как источники инфекции корневых гнилей озимой пшеницы

    Directory of Open Access Journals (Sweden)

    Shutko A. P.

    2013-01-01

    Full Text Available In the article, there are the data of a specific variety of cereal weed plants in crops of winter wheat on a black leached soil depending on the predecessor and the way of processing of a soil and its role as a source of an infection root rot. The greatest number of isolates of mushrooms – causative agents of a disease, was allocated from such weed plants as wheat grass creeping, eras galli, field (chess brome grass; the smallest – from Lolium temulentum. Fusariosis root decay dominates in community of cereal weed plants

  19. 黄芪根腐病病根的显微及超微结构研究%Study on the structure of Astragalus membranaceus roots infected by the root rot disease

    Institute of Scientific and Technical Information of China (English)

    赵庆芳; 张艳芳; 李巧峡

    2012-01-01

    The anatomical structure of Astragalus membranaceus roots infected by root rot, the way of pathogenic fungi invaded and the distribution of the fungi in the root are studied by paraffin sectioning and thin sectioning, taking the healthy roots as comparison, the result provide the theory basis for deeply researching the pathogenic mechanism of Astragalus membranaceus root rot. The results indicate that the only difference on the basic anatomical structure is that the fungi invade in the diseased roots and many pelotons in parenchymatous cells; The fungi don't infect the periderm, they enter the phloem parenchymas through periderm, and then, form pelotons, colonize and infect other cells continuously by means of hypha penetrating the cell wall, then they continue to infect the next parenchymatous cells, even xylem. The growth and proliferation of the fungi inhibite the growth of cells.%利用石蜡切片和超薄切片方法,以黄芪(Astragalus membranaceus)的健康植株作为对照,研究了黄芪根腐病病根的解剖结构、致病真菌的侵入方式以及在根内的分布,为进一步从细胞水平研究黄芪根腐病致病机理提供理论依据.结果表明:病根与健根的基本解剖结构没有明显的区别,主要差异是病根中有入侵的真菌,大量染色较深的茵丝结分布在薄壁组织细胞中;真菌侵入时不破坏周皮,其菌丝穿过周皮组织细胞进入韧皮薄壁组织,在薄壁细胞中形成菌丝结,并逐步扩展成一定的侵染区域,继而向下一层薄壁组织细胞内侵入,严重时甚至侵染到木质部.真菌的生长和增殖抑制了细胞的生长.

  20. 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

  1. Decolourization potential of white-rot fungus Phanerochaete chrysosporium on synthetic dye bath effluent containing Amido black 10B

    OpenAIRE

    Senthilkumar, S.; M. Perumalsamy; H. Janardhana Prabhu

    2014-01-01

    Synthetic azo dyes are extensively used in textile industry and are not easily degraded into the environment due to their complex structure. Due to the low degree of fixation of these dyes to fabrics, more than 10–15% of the dye does not bind to fabrics during colour processing and release into water bodies as effluent cause serious environmental pollution. White-rot fungus is found to be capable of degrading lignin which has a complex structure similar to azo dyes. In this study, the decolou...

  2. Identification of a nematode isolate from rot root of ramie%1种苎麻根腐病线虫的鉴定

    Institute of Scientific and Technical Information of China (English)

    余永廷; 薛召东; 曾粮斌; 张岗; 陈权; 朱爱国

    2011-01-01

    【Objective】 The study conducted morphological and molecular identification of a plant parasitic nematode isolated from rot root of ramie,which may lay a foundation for developing a molecular detection method of pathogen and integrated control.【Method】 A plant pathogenic nematode was isolated from rot root of ramie in Yuanjiang.The nematode was investigated under the microscope for initial identification.rDNA-ITS region was amplified using DNA extracted from single nematode and sequenced.The sequence was analysed by DNAstar and DNAMAN software for further identification.【Result】 The nematode was preliminarily identified as Pratylenchus coffeae by morphological characters.Furthermore,the identity of rDNA-ITS sequence is 99.8%,99.0%,98.0%,97.8% and 94.6% with populations from Hubei(China),Vet Nam,Taiwan,Japan and Nigeria,respectively.The GenBank accession number of this rDNA-ITS sequence is HQ403649.【Conclusion】 The morphological and molecular character indicated that the nematode was P.coffeae.%【目的】对分离的一种苎麻根腐病线虫进行形态和分子生物学鉴定,为病原线虫分子生物学检测技术的研发及苎麻根腐病的防治奠定基础。【方法】从感染苎麻根腐病植株根中分离出一种植物病原线虫,利用显微技术观察线虫的形态特征,对其进行初步鉴定;之后采用分子生物学技术,提取单条线虫的DNA,利用通用保守性引物扩增了线虫核糖体DNA内部转录间隔区(rDNA-ITS)序列,并用软件DNAstar和DNAMAN进行序列分析,对该植物病原线虫进行进一步鉴定。【结果】根据形态特征,将获得的苎麻根腐病线虫初步鉴定为咖啡短体线虫。序列分

  3. Screening of Indoor Biological Agents for Ginseng Root Rot Fungus%防治人参根腐病的生物制剂筛选

    Institute of Scientific and Technical Information of China (English)

    钟嘉丽; 张苏宏; 魏书琴; 王艳玲; 张忠宝

    2015-01-01

    To determine 6 kinds of biological agents for inhibition effect of ginseng root rot fungus by the mycelium growth rate method.The results showed that the sequence of the inhibiting effect from strong to weak was Bacillus subtilis,Bacillus mucilaginosus,Efective Micro-organisms,Bacillus mucilaginosus,Phosphate-solubilizing microorganisms,Sporotrichum thermophile, Trichoserma harzianum.B.subtili,B. mucilaginosus had obviously inhibitory effect on ginseng root rot fungus. B. Subtilis had the strongest inhibiting effect whose EC50 was 0.17 mg/L. B. mucilaginosus had the second best inhibiting effect whose EC50 was 707 mg/L. The inhibitory effect of Efective Micro-organisms,B. mucilaginosus,Phosphate-solubilizing microorganisms,S. ther-mophile ans T. harzianum were relatively poor, whose EC50 were 1 148、3 630、7 943、91 201 mg/L respectively.%通过菌丝生长速率法测定了6种生物制剂对人参根腐病菌的抑制效果. 结果显示,抑制作用由强到弱依次为枯草芽孢杆菌、苏云金杆菌、EM菌肥、解磷菌、嗜热性侧孢霉、哈茨木霉菌. 其中枯草芽孢杆菌、苏云金杆菌对人参根腐病菌均具有明显的抑制作用,以枯草芽孢杆菌抑制作用最强,其EC50为0.17 mg/L;苏云金杆菌次之,EC50为707 mg/L;EM菌肥、解磷菌、嗜热性侧孢霉、哈茨木霉菌的EC50分别为1 148、3 630、7 943、91 201 mg/L,抑菌效果较差.

  4. Effect of Bio-Control Agents on Yield, Yield Components and Root Rot Control in two Wheat Cultivars at New Valley Region

    Directory of Open Access Journals (Sweden)

    Mohamed Yosseif MOUBARK

    2011-11-01

    Full Text Available This study evaluated the effectiveness of applying the bioagents Bacillus subtilis (isolate BSM1, B. megaterium (isolate BMM5, Trichoderma viride (isolate TVM2 and T. harzianum (isolate THM4 for the control of rot root disease caused by Fusarium graminearum, Drechslera halodes and Rhizoctonia solani on two wheat cultivars (�Sakha 93� and �Bani Suif 5� under greenhouse conditions. Moreover, their effect wheat growth and yield were also studied under field conditions. In vitro, all tested bioagents were significantly in the reduced redial growth of the pathogenic fungi. Trichoderma viride was active more than the other tested bioagents followed by T. harzianum, while B. subtilis was the least ones. Under greenhouse conditions, all tested bioagents were able to reduce significantly damping-off and root rot caused by the tested pathogens compared with control and increased fresh and dry weight of the survival plants when applied as soil or grain treatments however, there was variation among bioagent isolates effect on reduction of disease severity both application methods. Trichoderma viride and B. megaterium were recorded the highest effective in this respect compared with other tested bioagents. Under field conditions, analysis of variance and mean performance were estimated for four characters: grain yield 4.8 m-2, No. of spikes m-2, No. of kernels spike-1 and 1000-kernel weight. Significant mean squares were obtained for all studied characters between the seasons (S, methods (M, (S (M, treatments (T, (S (T, (M (T and (S (M (T for �Sakha 93� cultivar and �Bani Suif 5� cultivars except application methods and (S (M for number of kernels spike-1 and 1000-kernel weight, respectively. While the treatments T. harzianum and B. megaterium were best treatments to increase grain yield, the treatments B. subtilis and T. harzianum were best treatments to increase number of spikes and the treatments B. subtilis and B. megaterium were best

  5. Decolourization potential of white-rot fungus Phanerochaete chrysosporium on synthetic dye bath effluent containing Amido black 10B

    Directory of Open Access Journals (Sweden)

    S. Senthilkumar

    2014-12-01

    Full Text Available Synthetic azo dyes are extensively used in textile industry and are not easily degraded into the environment due to their complex structure. Due to the low degree of fixation of these dyes to fabrics, more than 10–15% of the dye does not bind to fabrics during colour processing and release into water bodies as effluent cause serious environmental pollution. White-rot fungus is found to be capable of degrading lignin which has a complex structure similar to azo dyes. In this study, the decolourization potential of white-rot fungus Phanerochaete chrysosporium, which is capable of decolourizing synthetic dye bath effluent, was investigated. Maximum decolourization of 98% was achieved on the third day under normal conditions. The rate of decolourization carried out at different concentrations revealed that the increase in dye effluent concentration suppresses the percentage decolourization. The optimized amounts of nutrients were found to be 0.5%, 0.1% and 0.5% of glucose, manganese sulphate and ammonium salts, respectively. The addition of inducers such as starch and lignin increased enzyme production and the rate of decolourization.

  6. 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.

  7. 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.

  8. In-Vitro Evaluation of Fungicides and Fungicide Combinations Against Fusarium Root-Rot Fungal Pathogens of French Beans(Phaseolus Vulgaris L. c v. Monel

    International Nuclear Information System (INIS)

    Laboratories studies were undertaken to evaluate In-vitro efficacy of captan, thiram, pyrazophos, triforine and metalaxyl + mancozeb fungicides against Fusarium solani (Mart.) Appel and Wollenw fsp. phaseoli (Burk) Synder and Hansen Fusarium oxysporum Schlecht fsp. phaseoli kend and Synder root-rot fungal pathogens of French beans. Five fungicides and four combinations were tested for their antifungal activity. Fungicides treatments significantly (P=0.05) inhibited mycelial growth and spore germination. Fungicides suppressed the growth of F. oxysporum fsp. Phaseoli more than that of F. solani fsp. phaseoli. All fungicides except metalaxyl + mancozeb failed to suppress sporulation of the two fungi In-vitro. In the case of thiram the sporulation capacity of F. oxysporum fsp. phaseoli 3.43 times higher than in the control. Although, no fungicides treatment was seen to inhibitor of all the three measures of fungitoxicity, the ranking of the best three fungicide treatments would be, thiram 50 + captan so > triforine > metalaxyl + mancozeb. The relatively higher inhibitory effect of fungicides on the growth of F. oxysporum Ssp. Phaseoli than that of F. solani fsp. Phaseoli suggested that F. oxysporum Esp. Phaseoli was more sensible to fungicide treatments. Such differences may reflect inherent variations in accessibility of the active toxicants within the fungal systems. The ability attributed to the low growth rate, N depletion temperature and oxygen

  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. Microbial Properties of Composts That Suppress Damping-Off and Root Rot of Creeping Bentgrass Caused by Pythium graminicola

    OpenAIRE

    Craft, C M; Nelson, E. B.

    1996-01-01

    Composts prepared from a variety of feedstocks were tested for their ability to suppress seedling and root diseases of creeping bentgrass caused by Pythium graminicola. Among the most suppressive materials in laboratory experiments were different batches of a brewery sludge compost and a biosolids compost from Endicott, N.Y. Batches of these composts that were initially not suppressive to Pythium damping-off became more suppressive with increasing compost age. Leaf, yard waste, food, and spen...

  12. Reading the “Schwarz” in the “Schwarz-Rot-Gold”: Black German Studies in the 21st Century

    OpenAIRE

    Nenno, Nancy P.

    2016-01-01

    In 2016, Black German Studies celebrates the 30th anniversary of the publication of Farbe bekennen: Afrodeutsche Frauen auf den Spuren ihrer Geschichte. The result of the encounter of Black German women in Berlin with Afro-Caribbean American activist-poet Audre Lorde in the mid-1980s, this text testifies to the power of transnational collaboration in the assertion of Black agency, as well as to the influence of American feminist and civil rights discourses in the West German context. The trut...

  13. 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.

  14. 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

    solarization (SPT; 6 black plastic solarization (SPN; 7 SPT + EB; 8 SPT + CR; 9 SPN + EB; 10 SPN + SO; 11 Trichodef (Trichoderma harzianum; and 12 control. In Experiment II (2008, treatments were the same except treatment 2, replaced by a protective agent (plant extracts, and in experiment III (2009 the treatments were: 1 SPT + sheep manure (EO; 2 SPN + EO; 3 SPT; 4 SPN; 5 biological control (Trichoderma spp.; and 6 chemical control (2 - (thiocyanomethylthio benzothiazole 30%. the results indicated that the clear plastic solarization treatments with or without organic amendments showed significant increases (p<0.05 from 22 to 34%yield and diameterwith respect to biological and chemical control, but the latter two treatments in the incidence and severity decreasedsignificantly (p<0.05 , so that the clearplastic solarization and biological control, are viable alternatives to control root rot in onion crops in Baja California, Mexico.

  15. Control of Black Rot Disease in Tomato Fruits by Using Formulated Ginger Essential oil Treated by Gamma Radiation

    International Nuclear Information System (INIS)

    Ginger essential oil (Zingiber officinale) treated by gamma radiation at dose of 10 kGy was selected as an active ingredient for formulation of the biocide. Liquid formulations (emulsifiable concentrates) were prepared using different emulsifiers (Emulgator B.L.M. and tween 80 or tween 20) and additive oil (soybean oil). Physicochemical properties of the formulated oil (spontaneous emulsification, emulsion stability; cold stability and heat stability, viscosity, surface tension and ph) were measured. The formulated oil was tested in vivo to investigate its efficiency for controlling the growth of Alternaria alternata inoculated into tomato fruits. The results indicated that soaking inoculated tomato fruits in the formulated oil (ginger essential oil + soybean oil + emulgator B.L.M. + tween 80) treatment at concentration of 300 ppm for a period of 12 minute was the most effective for controlling the growth of the tested fungus. In addition, the formulated oil had efficiency for controlling the rot development on tomato fruits when applied as therapeutic and protective agents

  16. 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.

  17. In vitro selection of an effective fungicide against Armillaria mellea and control of white root rot of grapevine in the field.

    Science.gov (United States)

    Aguín, Olga; Mansilla, J Pedro; Sainz, María J

    2006-03-01

    Armillaria mellea (Vahl ex Fr) Kummer is an aggressive pathogen which causes white root rot in a wide range of hosts. Most chemicals tested so far against Armillaria, both in vitro and in the field, have not been effective in reducing fungal growth and/or preventing plant decline and mortality. In the present work the effects of four DMI (sterol demethylation inhibitor) fungicides, cyproconazole, hexaconazole, propiconazole and tetraconazole, and another six downwardly mobile systemic chemicals, azoxystrobin, cubiet (copper bis(ethoxy-dihydroxy-diethylamino)sulfate), fosetyl-Al, potassium phosphite, sodium tetrathiocarbonate (STTC) and 2-(thiocyanomethylthio)benzothiazole (TCMTB), on the mycelial growth of A. mellea were compared and evaluated; the product yielding the best results in in vitro experiments was selected to determine its efficacy in preventing decline and mortality of grapevines in the field. Best results on in vitro fungal growth reduction were obtained with the four azoles tested, in particular with cyproconazole and hexaconazole, achieving 67-72% mycelial growth inhibition at the lowest dose. Results obtained in the field showed that a dose of 50 mg AI litre(-1) of cyproconazole once or twice a year was efficient in controlling the disease even in vines seriously affected by the pathogen. However, further research is required to study minimum effective doses, residual effects and the convenience of the application of annual dressings in damaged vineyards, so as to gradually reduce the pathogen inoculum potential in soil and control the disease while reducing chemical residues in the plant and preventing development of fungal resistance. PMID:16475239

  18. 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.

  19. 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.

  20. Efficacy of wild plant in combination with microbial antagonists for the control of root rot fungi on mungbean and cowpea

    International Nuclear Information System (INIS)

    Present work was carried out to investigate the efficacy of Aerva javanica in combination with different microbial antagonists namely Rhizobium meliloti, Pseudomonas aeruginosa, Trichoderma harzianum and Aspergillus niger. Soil amended with A. javanica stem, leaves, flower powder at the rate1% w/w and seeds of cowpea (Vigna unguiculata L.) and mungbean (Vigna radiata L.) were coated with microbial antagonists for the control of root infecting fungi like Macrophomina phaseolina (Tassi) Goid, Fusarium spp. and Rhizoctonia solani Kiihn. Infection of M. phaseolina and R. solani were completely suppressed when seeds were coated with P. aeruginosa, T. harzianum, A. niger, R. meliloti and A. javanica leaves powder mixed in soil at the rate 1% w/w. All antagonists showed reduction in combination with A. javanica leaves powder at the rate1% but T. harzianum and P. aeruginosa in combination with A. javanica leaves showed promising results in complete reduction of R. solani and M. phaseolina on both crops. All growth parameters were maximum when soil was amended with A. javanica leaves powder at the rate 1% w/w and seeds were coated with T. harzianum and P. aeruginosa. (author)

  1. 文山三七根腐病病原真菌的鉴定与药剂防治%Identification of Root Rot Pathogen of Panax notoginseng from Wenshan

    Institute of Scientific and Technical Information of China (English)

    汪静; 梁宗锁; 康冰; 罗美佳

    2015-01-01

    从云南文山三七药材基地感染根腐病的三七组织获得分离物,并对其进行培养和纯化,并运用科赫法则(Koch,s Postulate)进行病原菌回接感染,得3株致病明显的菌株,后对此菌株进行生物学和18S-rDNA全序列分析鉴定及室内药效防治.结果表明,此3株菌分别是尖孢镰刀菌(Fusarium oxysporum),茄病镰刀菌(Fusarium solani)和链格孢菌(Alternaria alternata).甲基硫菌灵、根康、多菌灵对茄孢镰孢菌、尖镰孢菌的抑菌效果最好,腐霉利、甲基硫菌灵对链格孢菌的抑菌效果最好.该研究可为尖孢镰刀菌、茄病镰刀菌和链格孢菌引起的三七根腐病的防治提供参考.%To isolate and identify root rot pathogens of Panax notoginseng to lay the foundation for the prevention of the root rot disease.P.notoginseng root rot tissues and soils around roots were colleted in Wenshan,Yunnan.Microorganisms were examined based on Koch 's Postulate and 18S-rDNA sequence analysis.The results showed that in vitro pathogenecity tests demonstrated that Fusarium oxysporum,Fusarium solani and Alternaria alternate could result in the disease at different levels.The results of the PDA plate bacteriostatic experiment indoor showed that thiophanate-methyl,Genkang,and carbendazim had the best control effects on F.oxysporum,F.solani.While thiophanate-methyl,procymidone had the best control effect on A.alternate.F.oxysporum,F.solani and A.alternate were considered as three of the most important fungi causing P.notoginseng root-rot diseases.

  2. Analysis on the Field Tests of Several Kinds of Fungicides to Prevent Root Rot in Mung Bean%几种杀菌剂防治绿豆根腐病田间药效试验分析

    Institute of Scientific and Technical Information of China (English)

    曾玲玲; 刘峰; 崔秀辉; 李清泉; 王成; 闫锋; 赵秀梅; 季生栋

    2011-01-01

    以绿豆品种绿丰5号为试材,研究了35%甲霜灵干粉剂、50%福美双可湿性粉剂和35%多.福.克悬浮种衣剂3种药剂对其根腐病的防治效果。结果表明:35%多.福.克悬浮种衣剂,药种比1∶40拌种处理的产量极显著高于其它处理,为1 413.7 kg.hm-2;其对绿豆根腐病的防治效果较好,并且持效期长。绿豆出苗后10、30、60 d对绿豆根腐病的防治效果分别为82.6%、64.1%和69.4%。%The prevention effect of 35 % Metalaxyl DP, 50 % Thiram WP and 35 % Carbendazim· Thiram · Carhofuran FS on root rot of mung bean was studied. The results showed that., the yield of the treatment by seed dressing on the ratio of 1 : 40 of 35 % Carbendazim. Thiram- Carbofuran FS was extremely significant higher than the other treatments,and it was 1 413.7 kg·hm^2. Its prevention effect on the root rot of mung bean was the best and had long lasting time. The prevention effect of mung bean root rot were 82. 6 %-0.64. 1 % and 69.4% respectively at 10,30 and 60 days after mung bean emergence.

  3. 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.

  4. 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.

  5. 北疆地区打瓜镰刀菌根腐病药剂防治研究%Study on Fungicides for Controlling Root Rot of Seed Watermelon in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    朱亚峰; 李平; 金玉华; 张莉

    2013-01-01

    [Objective] Root rot of seed watermelon (Fusarium solani) is a major disease to seed watermelon in Xinjiang,the control efficacy of six fungicides to root rot was studied.The objective was to make some contributions to the control of the disease.[Method] The control efficacy of six bactericides to root rot of seed watermelon with experiments of indoor toxicity trials,potted trials and field plot trials were compared.[Result] Indoor toxicity trials shows that ethylicin is the most effective fungicide against the pathogen with EC50 of 31 mg/L,then it is followed by carbendazim,hymexazol,difenoconazole-thiram,bacillus subtilis,trichloroisocyanuric acid.Potted trials show that the control efficacy of irrigating roots is better than seed dressing.The control effects of carbendazim is the highest,the average control efficacy reached to 83.0%,followed by hymexazol and difenoconazole-thiram,with the average control efficacy of 64.4% and 60.2%.Field plot trials show that the control effects of difenoconazole-thiram is the highest,which the average control efficacy reached to 46.6%,followed by carbendazim and hymexazol,with the average control efficacy of 45.3% and 45.1%.[Conclusion] Difenoconazole-thiram,carbendazim and hymexazol have better control effect against root rot of seed watermelon%[目的]打瓜根腐病是北疆地区打瓜上的重要病害,明确几种杀菌剂对打瓜根腐病的防治效果,为打瓜根腐病的有效防治奠定基础.[方法]采用室内毒力测定、盆栽药效试验和小区药效试验,比较6种杀菌剂对打瓜根腐病的防治差异.[结果]室内毒力测定表明:乙蒜素对菌丝生长抑制效果最好,EC50值为31 mg、L,其他依次为多菌灵、恶霉灵、苯甲·福美双、枯草芽孢杆菌、三氯异氰尿酸.盆栽试验表明:药剂灌根的防治效果比药剂拌种好,其中多菌灵灌根防治效果最好,防治效果为83.0%,其次是恶霉灵和苯甲·福美双,防治效果分别为64.4

  6. Research Progress of Controlling Conifer Root and Butt Rots by Phlebiopsis gigantea%大伏革菌防治针叶树根腐病的研究进展

    Institute of Scientific and Technical Information of China (English)

    李杏春; 何双辉

    2014-01-01

    Conifer root and butt rots is an common forest disease in the north temperate zone, and the pathogen is Heterobasidion spp. But with the development of molecular biology, transcriptomics and genomics, we will change our mind to the genes related to controlling efficacy of Phlebiopsis gigantea. Phlebiopsis gigantea is the best antagonistic fungus to prevent the disease. This paper began with controlling Heterobasidion spp. and expounded research progress of controlling conifer root and butt rots by Phlebiopsis gigantea, which included the history of controlling disease, products based on Phlebiopsis gigantea, the mechanisms, ecological influence and process of screening.%叶树根腐病是北温带地区一种重要的森林病害,其病原为异担子菌Heterobasidion,应用大伏革菌对该病害进行生物防治是目前最常用的方法。而随着分子生物学、转录组学及基因组学的发展,未来的研究重点将集中在与大伏革菌拮抗效率相关的基因上。从异担子菌的防治入手,重点阐述了用大伏革菌防治针叶树根腐病的国内外研究进展,包括大伏革菌防病历史、商业化制剂产生、防病机制、生态影响和筛选过程等。

  7. Effect of BRF-1 and BRF-2 on Root Rot and Seed Yield in Soybean%生防菌BRF-1和BRF-2对大豆根腐病和产量的影响

    Institute of Scientific and Technical Information of China (English)

    周克琴; 韩秉进; 张秋英; 刘文志; 宫学凯; 李艳华; 孟英; 王光华

    2012-01-01

    BRF-1 (Paenibacillus Polymyxa) and BRF-2 {Bacillus subtilis) are gram-positive bacteria obtained from soybean root rhizosphere. Dual-culture tests showed they had strong antagonism to many fungal pathogens,while they inhibited the development of plant diseases in vitro experiment. In 2010,a field trial with BRF-1 and BRF-2 was carried out in northern region of Heilongjiang Province to investigate their field performance in reducing disease incidence of soybean. Both BRF-1 and BRF-2 inhibited soybean root rot with a reduction in disease severity index by 44.4% and 8. 8% ,respectively. BRF-1 was a potential plant growth promoting bacteria in controlling soybean root rot,which increased above-ground dry matter and root dry matter accumulation at flowering and initial seed-filling stages,and thus enhanced seed yield by 5.9%.%BRF-1和BRF-2是中国科学院东北地理与农业生态农田分子生态学科组从大豆根际土壤筛选得到的2株革兰氏阳性生防细菌,为了检测它们对田间大豆根腐病的防治效果,2010年在沈阳军区龙镇农副业基地对BRF-1和BRF-2进行田间试验.结果表明:2株生防细菌均有效地抑制了大豆根腐病的发生,发病程度分别降低44.4%和8.8%,BRF-1菌株效果较好,在降低大豆根腐病病情指数的同时,能增加大豆植株花期、始粒期地上部和地下部干物重,提高大豆产量5.9%,是一株很有潜力的生防菌.

  8. Root mass, net primary production and turnover in aspen, jack pine and black spruce forests in Saskatchewan and Manitoba, Canada.

    Science.gov (United States)

    Steele, Sarah J.; Gower, Stith T.; Vogel, Jason G.; Norman, John M.

    1997-01-01

    Root biomass, net primary production and turnover were studied in aspen, jack pine and black spruce forests in two contrasting climates. The climate of the Southern Study Area (SSA) near Prince Albert, Saskatchewan is warmer and drier in the summer and milder in the winter than the Northern Study Area (NSA) near Thompson, Manitoba, Canada. Ingrowth soil cores and minirhizotrons were used to quantify fine root net primary production (NPPFR). Average daily fine root growth (m m(-2) day(-1)) was positively correlated with soil temperature at 10-cm depth (r(2) = 0.83-0.93) for all three species, with black spruce showing the strongest temperature effect. At both study areas, fine root biomass (measured from soil cores) and fine root length (measured from minirhizotrons) were less for jack pine than for the other two species. Except for the aspen stands, estimates of NPPFR from minirhizotrons were significantly greater than estimates from ingrowth cores. The core method underestimated NPPFR because it does not account for simultaneous fine root growth and mortality. Minirhizotron NPPFR estimates ranged from 59 g m(-2) year(-1) for aspen stands at SSA to 235 g m(-2) year(-1) for black spruce at NSA. The ratio of NPPFR to total detritus production (aboveground litterfall + NPPFR) was greater for evergreen forests than for deciduous forests, suggesting that carbon allocation patterns differ between boreal evergreen and deciduous forests. In all stands, NPPFR consistently exceeded annual fine root turnover and the differences were larger for stands in the NSA than for stands in the SSA, whereas the difference between study areas was only significant for black spruce. The imbalance between NPPFR and fine root turnover is sufficient to explain the net accumulation of carbon in boreal forest soils. PMID:14759831

  9. Screening,Identification and Biocontrol Potential of Antagonistic Fungi Against Strawberry Root Rot and Plant Growth Promotion%草莓根腐病拮抗真菌筛选鉴定及其防病促生作用

    Institute of Scientific and Technical Information of China (English)

    申光辉; 薛泉宏; 张晶; 段佳丽; 王东胜; 杨兴华

    2012-01-01

    fungi based on root-zone microflora differentiae between healthy and root rot diseased strawberry plants. [Method] The isolated antagonistic fungi were identified according to colony and morphological characteristics observed by scanning electron microscope (SEM) and rDNA-ITS sequences analysis. Mycelium growth rate method and slide dual culture method were used to investigate antagonistic activity of cell-free culture filtrate and the antagonistic effect of antagonistic fungi against soil-borne pathogens, respectively. The seed germination promotion activity of culture filtrate was measured by Petri dish assays: A pot experiment was conducted to evaluate the control efficiency of antagonistic fungi against strawberry root rot caused by Cylindrocarpon macrodidyma CF9 and plant growth promotion effect. Colonization capacity and microbial flora were also determined by dilution plate count method. [Result] Strain HF3 and strain HF7 were identified as Penicillium griseofulvum and Aspergillus terreus, respectively. The cell-free culture filtrate both of two strains exhibited strong antagonistic effect on mycelium growth of test pathogens. The mycelium inhibitory rate of strain HF3 culture filtrate on Rhizoctonia solani and Verticillium dahliae were 100.0% after 96 h. It was also observed that HF3 broke the hyphae of C. macrodidyma CF9, such as contorting, slimmer, bulging, dissolved, protoplasm condense. It was observed that 103 and 104 diluted-fold filtrate of two strains enhanced the melon seed germination and growth, 104 diluted-fold filtrate of HF7 promoted seed germination, plumule and radicle growth of watermelon. In a pot experiment, the control efficiency against root rot of strawberry of HF3 and HF7 were 53.0% and 46.9%, respectively. Moreover, two antagonistic strains exhibited strawberry plant growth promotion as well as fruit yield enhancement. HF3 and HF7 efficiently colonized strawberry root with rhizoplane densities 2.23×105, 1.02×l05 CFU·g-1 dry soil

  10. Contribution of root respiration to soil surface CO2 flux in a boreal black spruce chronosequence.

    Science.gov (United States)

    Bond-Lamberty, Ben; Wang, Chuankuan; Gower, Stith T

    2004-12-01

    We quantified the contributions of root respiration (RC) and heterotrophic respiration to soil surface CO2 flux (RS) by comparing trenched and untrenched plots in well-drained and poorly drained stands of a black spruce (Picea mariana (Mill.) BSP) fire chronosequence in northern Manitoba, Canada. Our objectives were to: (1) test different equations for modeling RS as a function of soil temperature; and (2) model annual RS and RC for the chronosequence from continuous soil temperature measurements. The choice of equation to model RS strongly affected annual RS and RC, with an Arrhenius-based model giving the best fit to the data, especially at low temperatures. Modeled values of annual RS were positively correlated with soil temperature at 2-cm depth and were affected by year of burn and trenching, but not by soil drainage. During the growing season, measured RC was low in May, peaked in late July and declined to low values by the end of the growing season. Annual RC was < 5% of RS in the recently burned stands, approximately 40% in the 21-year-old stands and 5-15% in the oldest (152-year-old) stands. Evidence suggests that RC may have been underestimated in the oldest stands, with residual root decay from trenching accounting for 5-10% of trenched plot RS at most sites. PMID:15465701

  11. Effect of phosphate 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...... to measure the activity of the pathogen in roots. The enzyme activity increased with disease severity and disease incidence, except in plants supplemented with P at the highest level, where a peak in activity was seen 12 days after inoculation with the pathogen, followed by a decrease in activity...

  12. Screening of Rhizobacteria for Their Plant Growth Promotion Ability and Antagonism Against Damping off and Root Rot Diseases of Broad Bean (Vicia faba L.)

    OpenAIRE

    S Indira Devi; Talukdar, N. C.; K. Chandradev Sharma; Jeyaram, K.; Rohinikumar, M.

    2011-01-01

    Development of microbial inoculants from rhizobacterial isolates with potential for plant growth promotion and root disease suppression require rigorous screening. Fifty-four (54) fluorescent pseudomonads, out of a large collection of rhizobacteria from broad bean fields of 20 different locations within Imphal valley of Manipur, were initially screened for antifungal activity against Macrophomina phaseolina and Rhizoctonia solani, of diseased roots of broad bean and also three other reference...

  13. 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

  14. Levantamento da intensidade da alternariose e da podridão negra em cultivos orgânicos de brássicas em Pernambuco e Santa Catarina Survey of the intensity of Alternaria black spot and black rot on brassica species under organic farming systems in Pernambuco and Santa Catarina states, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz A M Peruch

    2006-12-01

    Full Text Available O objetivo deste trabalho foi avaliar a intensidade da alternariose, causada por Alternaria brassicicola e/ou Alternaria brassicae, e da podridão negra, causada por Xanthomonas campestris pv. campestris, em cultivos orgânicos de brássicas em Pernambuco e Santa Catarina. Os levantamentos foram realizados no período de novembro de 2001 a fevereiro de 2002, num total de 103 cultivos orgânicos de várias espécies de brássicas. Foram registradas elevadas prevalências das doenças nos estados, com exceção em couve-chinesa em Santa Catarina. A prevalência da alternariose foi 100% nos cultivos de brócolis em Pernambuco, bem como em couve-flor nos dois estados, enquanto a podridão negra atingiu esse nível nos cultivos de brócolis e couve-flor em Santa Catarina. Na média das diferentes espécies de brássicas, as doenças foram mais prevalentes em Pernambuco que Santa Catarina. Entretanto, as médias de severidade de cada doença no conjunto das brássicas não foram diferentes entre os estados, embora as condições climáticas tenham sido nitidamente distintas. A severidade da alternariose variou entre as espécies de brássicas somente em Pernambuco, com a menor severidade registrada em couve-manteiga. Em relação à podridão negra, apenas em Santa Catarina houve diferença na severidade entre as brássicas, sendo registrados os menores níveis em couve-chinesa. Não foram constatadas correlações significativas entre os níveis de severidade da alternariose e da podridão negra, bem como da severidade destas com o número total de plantas e a idade das plantas nos cultivos.The objective of this research was to evaluate the intensity of Alternaria black spot, caused by Alternaria brassicicola and/or Alternaria brassicae, and black rot, caused by Xanthomonas campestris pv. campestris in organic cultivation of brassicas in Pernambuco and Santa Catarina. The survey was carried aut from November 2001 to February 2002, in 103 fields under

  15. Screening of Rhizobacteria for Their Plant Growth Promotion Ability and Antagonism Against Damping off and Root Rot Diseases of Broad Bean (Vicia faba L.).

    Science.gov (United States)

    Indira Devi, S; Talukdar, N C; Chandradev Sharma, K; Jeyaram, K; Rohinikumar, M

    2011-01-01

    Development of microbial inoculants from rhizobacterial isolates with potential for plant growth promotion and root disease suppression require rigorous screening. Fifty-four (54) fluorescent pseudomonads, out of a large collection of rhizobacteria from broad bean fields of 20 different locations within Imphal valley of Manipur, were initially screened for antifungal activity against Macrophomina phaseolina and Rhizoctonia solani, of diseased roots of broad bean and also three other reference fungal pathogens of plant roots. Fifteen fluorescent pseudomonas isolates produced inhibition zone (8-29 mm) of the fungal growth in dual plate assay and IAA like substances (24.1-66.7 μg/ml) and soluble P (12.7-56.80 μg/ml) in broth culture. Among the isolates, RFP 36 caused a marked increase in seed germination, seedling biomass and control of the root borne pathogens of broad bean. PCR-RAPD analysis of these isolates along with five MTCC reference fluorescent pseudomonas strains indicated that the RFP-36 belonged to a distinct cluster and the PCR of its genomic DNA with antibiotic specific primers Phenazine-1-carboxylic acid and 2, 4-diacetyl phloroglucinol suggested possible occurrence of gene for the potent antibiotics. Overall, the result of the study indicated the potential of the isolate RFP 36 as a microbial inoculant with multiple functions for broad bean. PMID:22282623

  16. Identification of the Pathogen of Black-rot Disease in Dracaena sanderiaha cv. Golden edge and Its Control Method%金边富贵竹黑腐病病原鉴定及防治方法研究

    Institute of Scientific and Technical Information of China (English)

    吴赟生; 张森泉; 高洋; 张荣

    2011-01-01

    [ Objective ] The research aimed to determine the species of pathogen caused the black-rot disease in Dracaena sanderiana cv. Golden edge, and to screen the effective fungicides to control the disease. [ Method ] Disease samples with typical symptoms were collected to isolate the pathogen based on Koch's rule, and the morphological characteristics of the pathogen was observed under microscope. The inhibition effect of 9 different fungicides with two different concentrations against the pathogen was determined. [ Result ] The black-rot disease of Dracaena sanderiana cv. Golden edge was caused by Aspergillus niger N.Tiegh. Thiophanate-methyl, Hymexazol, Mancozeb, Viziam, Dimethomorph and Fuklasin had strong inhibition effects on the mycelia growth of A. niger. When the concentration of the above fungicides was 500 mg/L,the inhibitory rate against A. niger was 100%. Artificial inoculation test showed that when the solutions of Viziam and Dimethomorph with the effective concentration of 1 000 mg/L were sprayed on the leaves, the control effect was 100%. [ Conclusion ]50% Viziam and 69% Dimethomorph were recommended to select for control the black-rot disease of Dracaena sanderiana cv. Golden edge.%[目的]明确金边富贵竹黑腐病病原菌种类,筛选出对该病害有防治作用的杀菌剂.[方法]采集具有典型症状的病害标本,根据柯赫氏法则分离病原物,在显微镜下观察病原物形态特征;分别测试2种不同浓度下的9种供试杀菌剂对该病原菌的抑制作用.[结果]引起金边富贵竹黑腐病的病原为半知菌亚门曲霉属的黑曲霉(Aspergillus niger N.Tiegh).杀菌剂甲基托布津、恶霉灵、代森锰锌、维鲜、烯酰吗啉、福·福锌等对该菌菌丝生长有较强的抑制作用,有效浓度为500mg/L时,抑菌率为100%.人工接种试验表明,有效浓度为1000 mg/L的维鲜或烯酰吗啉溶液喷施叶片防治效果为100%.[结论]防治金边富贵竹黑腐病推荐选用50%

  17. 薰衣草精油对樱桃番茄采后黑斑病的抑制活性%Control of black rot disease in postharvest cherry tomato with lavender oil

    Institute of Scientific and Technical Information of China (English)

    任雪艳; 梁卓; 王慧敏; 闫帆; 魏玉荣; 孔庆军

    2014-01-01

    This experiment was conducted to study the inhibitory effect and action mode of lavender oil against black rot in postharvest cherry tomato caused by Alternaria alternata by means of fumigation and direct contact. Lavender oil fumi-gation with the dosage of 5 μl per petri dish or direct contact at 400 μl/L could inhibit the growth of A. alternata complete-ly. The incidences of black rot were reduced by 54% and 60% in post harvest cherry tomatoes fumigated with 100 μl/L lavender oil and directly contacted with 500 μl/L lavender oil respectively. An inhibitory effect of short-time lavender oil treatment was shown on A. alternata while a lethal effect of long-time lavender oil treatment was exhibited.%为薰衣草精油用于防治樱桃番茄采后黑斑病提供依据,研究了薰衣草精油熏蒸和直接接触对病原真菌链格孢( Alternaria alternata)的抑制活性及作用方式。结果表明,在培养基培养试验中,每皿5μl的薰衣草精油熏蒸即可完全抑制病原菌的生长;当400μl/L薰衣草精油直接接触链格孢病原菌时,可完全抑制病原菌的生长。在薰衣草精油对樱桃番茄果实采后黑斑病抑制效果试验中发现,100μl/L精油熏蒸处理果实时,处理组果实发病率比对照组降低54%,用500μl/L精油直接处理果实时,处理组果实发病率则比对照组降低60%。在薰衣草精油对病原真菌链格孢作用方式试验中,薰衣草精油作用时间短时,对链格孢病原菌生长有抑制作用,薰衣草精油作用时间长时(5 d和7 d)对链格孢病原菌有致死效应。

  18. 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.

  19. 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.

    Directory of Open Access Journals (Sweden)

    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.

  20. 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

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

    OpenAIRE

    Montaser Fawzy ABDEL-MONAIM

    2011-01-01

    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...

  2. Black Locust (Robinia pseudoacacia L. Root Cuttings: Diversity and Identity Revealed by SSR Genotyping: A Case Study

    Directory of Open Access Journals (Sweden)

    Maria Emilia Malvolti

    2015-10-01

    Full Text Available Background and Purpose: Black locust (Robinia pseudoacacia L. is a valuable species native to North America and today widely planted throughout the world for biomass production. In Hungary, where Robinia has great importance in the forest management, the clones have been selected for plantations on good, medium and poor quality sites. To conserve the identity, superior clones are vegetatively propagated by root cuttings. At times the collection of root cuttings can cause uncertainty for clonal identity because of the overlap of roots from neighboring plants. This can occur especially when the repository is damaged from severe environmental accidents and the planting layout has been lost. The aim of this study has been to verify by molecular markers the diversity or identity of black locust clones by root cuttings harvested in a damaged trial. Materials and Methods: Root cuttings of 91 clones belonging to five cultivars were collected in a trial severely damaged by storms and flooding periods. The obtained plantlets were analyzed with nine microsatellite (SSR markers and the genetic identity/diversity within and among the plants was tested using the software GenAlEx version 6. Results: Multilocus genotypes (MLG and the Paetkau’s assignation test (1985 revealed genetic variability among the samples: the analyzed plantlets were grouped in four classes instead of the five expected. In addition, 6 unique genotypes have been detected. Conclusions: This study remarks problems that may arise during the harvest of Robinia’s root cuttings, especially when the planting layout has been confused. Molecular analyses can be successfully used to control the germplasm before its sale as guaranty for nurseries, farmers and stakeholders.

  3. 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

    Directory of Open Access Journals (Sweden)

    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

  4. 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

  5. New roots: Jamaican ontologies of blackness from Africa to the ghetto

    NARCIS (Netherlands)

    W. Modest; R. Jaffe

    2014-01-01

    This article explores contemporary ontologies of blackness in the Caribbean island of Jamaica. Approaching blackness as an ontological issue - an issue that pertains to the being, or the existence, of a category of people - we emphasize the spatial dimension of such ontologies. Drawing on Jamaican c

  6. Propagation of Black Plum (Vitex donania Sweet) Using Stem and Root Cuttings in the Ecological Conditions of South-Benin

    OpenAIRE

    Sanoussi, A.; Ahoton, LE.; Odjo, T.

    2012-01-01

    The black plum is a multi-purpose tree well known to the rural and urban populations of tropical Africa. Its uses are well documented, but its regeneration possibilities have not yet been studied, despite the importance of this species. The objective of this study is to ensure that this tree can be propagated from other organs instead of seeds. In order to achieve this, a trial propagation, using stem and root cuttings, was conducted on two types of substrate: topsoil at the planting site (sa...

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

    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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Screening Experiments for the Effective Fungicides of Black Rot Disease of Gonggan(Alternaria citri)%贡柑黑腐病有效防治药剂筛选

    Institute of Scientific and Technical Information of China (English)

    邓明学; 谢艳芳; 谭有龙; 覃旭; 覃星瑜; 覃宗典

    2012-01-01

    [目的]筛选防治贡柑黑腐病的有效药剂.[方法]用生长速率法和孢子萌发法测定苯醚甲环唑等15种药剂的EC50、EC95值,并做氟硅唑等5种药剂的田间药效试验.[结果]以EC95(mg a.i./L)排序,抑菌活性较高的有氟硅唑、吡唑醚菌酯·咪鲜胺、吡唑醚菌酯、苯醚甲环唑、咪鲜胺、代森锰锌、丙森锌、百菌清·多菌灵·代森锰锌;田间防效较好的有10%氟硅唑WP、25%苯醚甲环唑·咪鲜胺WP、50%百菌清·多菌灵·代森锰锌WP和72%代森锰锌·霜脲氰WP,而10%氟硅唑EW防效较差.[结论]耐雨水冲刷的杀菌剂和剂型防效较好.%[Aims] This paper aims to screen out the effective fungicides for controlling black rot disease of Gonggan(Alteranria citri). [Methods] The EC50 and EC95(mg a.i./L) of 15 different kinds of fungicides, such as ifenoconazole, pyraclostrobin, were tested with the both methods of the growth rate and spore emergence, meanwhile, the field control of five kinds of fungicides, such as flusilazole, were conducted. [Results] Sorting by EC,,, the effect on inhibition of mycelial growth and spore germination from high to low: flusilazole, pyraclostrobin+prochloraz, pyraclostrobin, difenoconazole, prochloraz, mancozeb, propineb. The field trial results showed that the following .fungicides have good effect: flusilazole 10% WP 1 g/L, difenoconazole+prochloraz 25% WP 1 g/L, chlorothalonil+carbendazim+mancozeb 50% WP 1.67 g/L and mancozeb+cymoxanil 72% WP 1.25 g/L, while flusilazole 10% EW 1 g/L with poor control efficiency. [Conclusions] The control effect is better of the fungicides whose formulations can resist rain erosion.

  13. 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

  14. 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.

  15. Severidade da podridão-radicular de Rhizoctonia do feijoeiro influenciada pela calagem, e pelas fontes e doses de nitrogênio Severity of Rhizoctonia root rot in beans influenced by liming, nitrogen sources and rates

    Directory of Open Access Journals (Sweden)

    Fabrício de Ávila Rodrigues

    2002-09-01

    Full Text Available Avaliou-se o efeito da calagem e de doses e fontes de N na severidade da podridão-radicular de Rhizoctonia (PRR em feijoeiro em condições controladas. No primeiro ensaio, utilizaram-se as doses de 0, 1,75, 2,25, 2,75, 3,25 e 3,75 g de calcário dolomítico por quilograma de solo. No segundo ensaio, os tratamentos constituíram um fatorial 2x6, ou seja: duas fontes de N (sulfato de amônio e nitrato de sódio e seis doses de N (0, 11, 16, 21, 26 e 31 mg kg-1 de solo. A acidez do material de solo usado no segundo ensaio foi corrigida com 1,75 g de calcário por quilograma de solo. Foram colocados 16 g de grãos de arroz infestados por R. solani em cada vaso com 1 kg de material de solo. Utilizou-se, em ambos os ensaios, o delineamento inteiramente casualizado, com cinco repetições. A severidade da PRR foi avaliada 25 dias após a emergência das plantas, atribuindo-se nota para cada planta de acordo com o tamanho das lesões formadas no hipocótilo. Os dados obtidos foram usados para calcular o índice de doença (ID, %. Foram obtidas equações lineares significativas que permitiram descrever as relações entre a calagem e fontes de N com a severidade da PRR. Houve um acréscimo de 32% no ID, em virtude das doses crescentes de calcário. Após a calagem, a aplicação de sulfato de amônio reduziu em 22% o ID, enquanto o nitrato de sódio o aumentou em 18%, com relação ao controle.The objective of this study was to determine the effects of liming, nitrogen sources and rates on the severity of Rhizoctonia root rot (RRR in beans under controlled conditions. In the first experiment, the soil was amended with 0, 1.75, 2.25, 2.75, 3.25 and 3.75 g of dolomitic lime per kilogram of soil. In the second experiment, the soil was fertilized with 0, 11, 16, 21, 26 and 31 mg N kg-1 of soil, using ammonium sulfate and sodium nitrate as N sources. For the second experiment, soil acidity was adjusted by applying 1.75 g of dolomitic lime per kilogram of

  16. 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.

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

    OpenAIRE

    Salami Olusola Abiodun; Popoola Omololu Olumide

    2007-01-01

    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 specie...

  18. Dynamics of depletion and replenishment of water storage in stem and roots of black spruce measured by dendrometers

    Directory of Open Access Journals (Sweden)

    Audrey eTurcotte

    2011-06-01

    Full Text Available In the short term, trees rely on the internal storage of water because it affects their ability to sustain photosynthesis and growth. However, water is not rapidly available for transpiration from all the compartments of the plant and the living tissues of the stem act as a buffer to preclude low water potentials during peaks of transpiration. In this paper, electronic dendrometers were used from mid-June to mid-September 2008 to compare the radius variations in stem and roots of black spruce [Picea mariana (Mill. B.S.P.] in two sites of the boreal forest of Quebec, Canada, with different soil characteristics and water retention. The duration of the daily cycles was similar between sites and measurement heights but greater amplitudes of contraction and expansion were observed on the stem and in the site with the shallowest soil organic layer. The expansion phase had higher amplitudes and lasted longer than contraction. On average, the contraction phase occurred between 07:00 and 16:30 (legal time, while expansion lasted 14.5 h. The roots in the site with the deepest organic layer showed a wider variation in the onset of contraction, which could be as late as 13:00. The probability of observing the contraction phase depended on precipitation. With a precipitation <0.5 mm h-1, the bivariate posterior probabilities estimated >60% probability of observing contraction between 05:00 and 21:00, decreasing to 20% with precipitation >1.1 mm h-1. These findings demonstrated that the depth of the organic layer plays an important role in maintaining the internal water reserve of trees. The dynamics of water depletion and replenishment can modify the water potential of xylem and cell turgor during the enlargement phase, thus affecting radial growth. Changes in temperature and precipitation regime could influence the dynamics of internal water storage in trees growing on shallower and drier soils.

  19. Dynamics of Depletion and Replenishment of Water Storage in Stem and Roots of Black Spruce Measured by Dendrometers

    Science.gov (United States)

    Turcotte, Audrey; Rossi, Sergio; Deslauriers, Annie; Krause, Cornelia; Morin, Hubert

    2011-01-01

    In the short term, trees rely on the internal storage of water because it affects their ability to sustain photosynthesis and growth. However, water is not rapidly available for transpiration from all the compartments of the plant and the living tissues of the stem act as a buffer to preclude low water potentials during peaks of transpiration. In this paper, electronic dendrometers were used from mid-June to mid-September 2008 to compare the radius variations in stem and roots of black spruce [Picea mariana (Mill.) B.S.P.] in two sites of the boreal forest of Quebec, Canada, with different soil characteristics and water retention. The duration of the daily cycles was similar between sites and measurement heights but greater amplitudes of contraction and expansion were observed on the stem and in the site with the shallowest soil organic layer. The expansion phase had higher amplitudes and lasted longer than contraction. On average, the contraction phase occurred between 07:00 and 16:30 (legal time), while expansion lasted 14.5 h. The roots in the site with the deepest organic layer showed a wider variation in the onset of contraction, which could be as late as 13:00. The probability of observing the contraction phase depended on precipitation. With a precipitation 60% probability of observing contraction between 05:00 and 21:00, decreasing to 20% with precipitation >1.1 mm h−1. These findings demonstrated that the depth of the organic layer plays an important role in maintaining the internal water reserve of trees. The dynamics of water depletion and replenishment can modify the water potential of xylem and cell turgor during the enlargement phase, thus affecting radial growth. Changes in temperature and precipitation regime could influence the dynamics of internal water storage in trees growing on shallower and drier soils. PMID:22639583

  20. Determination of caffeic acid in root and rhizome of Black cohosh (Cimicifuga racemosa (L. Nutt.

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    Zapala Karolina

    2014-06-01

    Full Text Available Cimicifuga racemosa, is a plant with a diverse and long history of medicinal use. Caffeic acid, bioactive compound, which often occurs with other polyphenols can influence the biological activity of this plant. The aim of our work was quantitative analysis of caffeic acid in roots and rhizomes of two varieties of C. racemosa. Analysis was performed by HPLC method. The extracts were separated on C18 reversed-phase column using mixture of methanol, water and formic acid (25:75:0.5 v/v/v as a mobile phase. The flow rate of eluent was 1.0 ml·min-1. The obtained validation parameters such as linearity, linear regression equation and precision expressed as a relative standard deviation were adequate for quantitative determination. Caffeic acid was found in all tested extracts. The highest total amount of caffeic acid was determined in C. racemosa var. racemosa (255.3 μg·g-1 while its concentration in C. racemosa var. cordifolia was significantly lower (213.0 μg·g-1.

  1. Differential expression of metallothionein type-2 homologues in leaves and roots of Black pepper (Piper nigrum L

    Directory of Open Access Journals (Sweden)

    Susan M. Alex

    2008-01-01

    Full Text Available Black pepper (Piper nigrum L., member of the family Piperaceae is indigenous to India and is one of the most widely used spices in the world. In this paper we report the results of our attempts to identify a set of genes differentially expressed in the leaves of Piper nigrum, which could facilitate targeted engineering of this valuable crop. A PCR-based Suppression Subtractive Hybridization (SSH technique was used to generate a leaf-specific subtracted cDNA library of Piper nigrum. A tester population of leaf cDNA was subtracted with a root derived driver cDNA. The efficiency of subtraction was confirmed by PCR analysis using the housekeeping gene actin. On sequence analysis, almost 30% of the clones showed homology to metallothionein type-2 gene. The predominance of metallothionein transcripts in the leaf was further confirmed using Real-Time PCR analyses and Northern blot. The possible role of metallothionein type-2 homologues in the leaf is discussed along with the feasibility of using SSH technique for identification of more number of tissue-specific genes from Piper nigrum.

  2. Arbuscular mycorrhizal colonization in black poplar roots after defoliation by a non-native and a native insect

    Directory of Open Access Journals (Sweden)

    Zampieri E

    2016-08-01

    Full Text Available A major goal in ecology is to understand how interactions among organisms influence ecosystem services. This work compares the effects of two Lepidoptera defoliators, one non-native (Hyphantria cunea and one native (Lymantria dispar to Europe, on the colonization of black poplar (the Populus nigra clone “Jean Pourtet” roots by an arbuscular mycorrhizal (AM symbiotic fungus (Funneliformis mosseae in a pot experiment. The effects of defoliation have also been assessed on the expression of fungal and plant genes playing a role during symbiosis. Both control and defoliated poplars have shown a low level of mycorrhization. Additionally, neither the non-native nor the native insect seem to strongly affect the AM colonization, at least at the time of observation (eight days from the end of the defoliation. Concerning the gene expression analysis, our results suggest that defoliation does not influence neither the expression of genes coding for a fungal and a plant phosphate transporter nor that of a gene coding for a fungal ATPase, and that there were no differences between defoliation carried out by the non-native and the native insect.

  3. 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.

  4. Avaliação da atividade de indutores de resistência abiótica, fungicida químico e extratos vegetais no controle da podridão-negra em Abacaxi 'Pérola' Activity evaluation of abiotic resistance inducers, chemical fungicide and natural plant extracts on black rot of pineapple, cv. pérola

    Directory of Open Access Journals (Sweden)

    Mônica Danielly de Mello Oliveira

    2009-03-01

    probabilidade. O tratamento que apresentou melhor resultado foi o indutor de resistência Ecolife®, aumentando o período de vida útil dos frutos e diminuindo a severidade dos sintomas da doença.Black rot of pineapple, caused by Chalara paradoxa (De Seyn. Sacc., is a postharvest disease responsible by high losses on fruits destined to the fresh market and to the processing industry. Penetration of fungus inside cells occurs through wounds and stem cutting, causing infection. The objective of this work was to evaluate the effect of abiotic resistance inducers, chemical fungicide and natural plant extracts on black rot of pineapple control. 32 fruits of pineapple cv pérola were used. They were disinfested with sodium hypochlorite (commercial product at 4% for 5 minutes. After drying at room temperature, fruits were treated, by spraying, with: 1 Distilled water (control, 2 Derosal 3 Bion® (Acibenzolar-S-methyl; 4 Ecolife®; 5 Agro-Mos®; 6 Allium sativum extract at 20%; 7 A. cepa at 20% and 8 Azadirachta indica at 20%. Treated fruits were incubated on humid chamber with polyethylene bags during 24 hours before inoculation procedure using a mycelia disk added to a wound at the epidermic area of the fruit. Evaluation of disease progress was done by a disease index: 1- no symptoms, 2- black rot on epidermis reaching 1-5 simple fruits, 3- black rot on epidermis reaching 6-10 simple fruits, 4- internal brown yellow rot, 5- black rot and disintegration of internal area in more than 50%. The experimental design was a completely randomized with eight treatments and five replicates, using general linear models with multinomial distribution and the averages were compared by Scott-Knott test at 5%. The best results were found in the Ecolife treatment with longer fruit life span and less severity in the symptoms of the disease.

  5. 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。

  6. Biomethanation of white rotted and brown rotted rice straw

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, A.; Bhattacharyya, B.C. [Chemical Engineeringg Dept., Biotechnology Unit, IIT Kharagpur, (India)

    1999-04-01

    Biomethanation of white rotted and brown rotted rice straw was taken for the present investigation and their efficiency on biomethanation has been tested. Rice straw was treated with white rot fungus Phanerochaete chrysosporium (P{sub C}) and brown rot fungus Polyporus ostreiformis (P{sub O}). Biogas and methane production was increased by about 34.73% and 46.19% in P{sub C}-treated straw and 21.12% and 31.94% in P{sub O}-treated straw respectively. VFA production has also been increased in P{sub C} and P{sub O} treated straw compared to control straw which were 76.73% and 30.69% respectively. Reduction of COD has also been found during biomethanation. The rate of reduction of COD during the initial period of digestion was 59.01%, 55.55% and 26.00% in P{sub C}-treated, P{sub O}-treated and control straw respectively after 21 days of digestion. (orig.) With 12 figs., 3 tabs., 14 refs.

  7. DEVELOPMENT AND SUPPRESSION OF GRAPEVINE BLACK FOOT CAUSED BY ILYONECTRIA RADICICOLA

    Directory of Open Access Journals (Sweden)

    Khadeeja A. Saido

    2013-04-01

    Full Text Available Present study investigated the development and suppression of grapevine black foot using a highly virulent strain of Ilyonectria radicicola during 2010-2012 after its widespread outbreak in Duhok - Iraq since 2008. Inoculated roots showed distinctive symptoms of sunken necrotic lesions with internal black streaking of rootstocks. Production of mycelial mass (in vitro was higher at pH 5.0 resulting in 57% severity of foot rot compared to 46.16% at pH 7.0. In general, Kamali cv. was the most susceptible cultivar with 59.29% of stubby root growth affected compared to 53.32% and 40.83% on Rashmew and Taefi cvs. respectively. Wounding roots of a susceptible cultivar developed the conspicuous symptoms of black foot rot with a severity of 90%. Increasing the conidial inoculum was essential for severe infection development to more than 62%, whereas interaction between inoculation and wounding of roots increased lesion severity to 80.09%. However, acidic pH significantly enhanced disease progression on inoculated vine cuttings to 84.41% compared to 40% at neutral pH. Unfortunately, inoculum of Ilyonectria radicicola was not suppressed significantly even with fungicide application and continued its damage on Rashmew cv. Resulting in disease severity of 23.70% . More than 25% of the inoculated vines grown in amendments of Trichoderma harzianum and farmyard manures were infected compared to 14.80% and 20.73% of the non-inoculated. Exclusion of fungal inoculum improved the plant vigours as measured by dry weight and shoot growth, whereas significant stimulation of root growth were evidenced in the amended treatments particularly those with farmyard manures and fungicides. 

  8. The Phenotype Evolution and Transfer Breeding of Black Rot Resistance in Somatic Hybrids Between Cauliflower and Black Mustard%花椰菜—黑芥体细胞杂种的性状演变和对黑腐病抗性的转育

    Institute of Scientific and Technical Information of China (English)

    张洁; 王桂香; 韩硕; 严红; 宗梅; 郭宁; 刘凡

    2016-01-01

    以对黑腐病(Black rot)感病的花椰菜(Brassica oleraceaL.var.botrytisL.,2n=18,CC)‘Korso’和抗病的黑芥(B.nigra,black mustard,2n=16,BB)‘G1/1’的体细胞杂种(简称PFCN,protoplast fusion of cauliflower and Brassica nigra)高代自交及回交后代为材料,根据表型特征将其分为4大类:性状介于花椰菜和黑芥之间的中间型材料(M)、向花椰菜过渡的过渡型(M-K)、偏花椰菜型(-K)和花椰菜型(K).连续5年的黑腐病人工接种鉴定结果显示:‘Korso’的病情指数在44 ~ 57之间,表现为耐病到感病;‘G1/1’在12 ~ 32之间,表现为抗病,从M、M-K、-K至K型,杂种后代病情指数总体上呈逐渐升高的趋势,其中M型和M-K型材料表现为高抗至抗病,-K型材料表现为抗病至耐病,K型材料表现为耐病.对2014年的15份典型-K至K型材料进行了形态演变及黑腐病抗性变化追溯:总体上,偏花椰菜的形态转变发生在S1BC4、55、S1BC3和BC3(S为自交,BC为回交)世代中,伴随着形态的转变,黑腐病病情指数急剧升高;同一年中来源相同或者相近的株系病情指数相差不多.2015年进一步对2014年25个单株的自交后代进行黑腐病抗病性跟踪鉴定:整体上病情指数呈下降趋势,仅少数株系表现上升;来源相同的衍生株系变化趋势几乎一致,且差异不大,说明这些材料系内对黑腐病抗病性逐年趋于稳定.目前获得了6份相对于受体亲本‘Korso’表现出了对黑腐病抗性显著提高的材料:PFCN14-15-4.1、PFCN14-15-5.1、PFCN 14-29-1.1和PFCN 14-29-1.2,连续3年病情指数呈下降趋势,并最终稳定在30左右;PFCN14-14-1.1和PFCN14-14-1.2则连续6年保持在20 ~ 38之间.

  9. 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

  10. Research on Forma Specialis of Fusarium solani Causing Root Rot of Tea Cutting Seedling and Discussion of Relevant Issues%茶扦插苗根腐性苗枯病菌茄镰孢霉专化型研究及相关问题的商榷

    Institute of Scientific and Technical Information of China (English)

    赖传雅; 赖传碧; 曾凡凯; 韦少敏; 李复新; 周国辉

    2012-01-01

    茶扦插苗根腐性苗枯病是广西一些茶圃的常见病害,严重影响茶苗出圃.明确该病病原菌分类地位可以为病害防治提供理论依据.为此,作者从桂北茶扦插苗圃中随机采得18株病株标本,分离出镰孢霉纯菌株16株,单孢菌纯系培养18株(GF01 ~ GF18号).参照BOOTH镰刀菌分类鉴定标准,对代表性单孢菌株GF08号的培养菌进行了形态鉴定;以蘸根法和土壤伤根法测试其致病性,同时在12科22种植物上进行接种试验.结果表明,该菌与茄镰孢霉[ Fusarium solani( Mart.)Sacc.]形态特征一致,经柯赫氏法则验证确定其为茶扦插苗根腐性苗枯病的病原菌.该菌除侵染山茶科的福云六号大叶种和白毛茶外,对其余11科20种植物均不致病.因此鉴定该菌为茄镰孢霉一新专化型:Fusarium solani (Mart.) Sacc.f sp.theae Chuan-Ya Lai et Chuan-Bi Lai.%Root rot of tea cutting seedling is a common and serious disease occurred in some tea nurseries in Guangxi, China. Determination of taxonomy status of the pathogen can provide theoretic basis for the disease control. So 18 diseased samples were collected from the tea nurseries in north Guilin of Guangxi, and pure cultures of 16 Fusarium isolates and monospore cultures of 18 strains (GF01 ~ GF18) were obtained. Typical strain GF08 was identified based on BOOTH's species concept for Fusarium and tested for pathogenicity by dipping seedling roots and micro injuring roots methods. Twenty-two plant species of 12 families were inoculated with strain GF08. The results showed that the morphological characters of strain GF08 was consistent with Fusarium solani (Mart. ) Sacc and its pathogenicity was confirmed by Koch's postulates. Except for Camellia sinensis and C. sinensis (Theaceae) , the pathogen did not infect other 20 plant species of 11 families. Therefore, the pathogen of root rot of tea cutting seedling was identified as a new forma specialis that was Fusarium solani ( Mart. ) Sacc

  11. Common roots: a contextual review of HIV epidemics in black men who have sex with men across the African diaspora.

    Science.gov (United States)

    Millett, Gregorio A; Jeffries, William L; Peterson, John L; Malebranche, David J; Lane, Tim; Flores, Stephen A; Fenton, Kevin A; Wilson, Patrick A; Steiner, Riley; Heilig, Charles M

    2012-07-28

    Pooled estimates from across the African diaspora show that black men who have sex with men (MSM) are 15 times more likely to be HIV positive compared with general populations and 8·5 times more likely compared with black populations. Disparities in the prevalence of HIV infection are greater in African and Caribbean countries that criminalise homosexual activity than in those that do not criminalise such behaviour. With the exception of US and African epidemiological studies, most studies of black MSM mainly focus on outcomes associated with HIV behavioural risk rather than on prevalence, incidence, or undiagnosed infection. Nevertheless, black MSM across the African diaspora share common experiences such as discrimination, cultural norms valuing masculinity, concerns about confidentiality during HIV testing or treatment, low access to HIV drugs, threats of violence or incarceration, and few targeted HIV prevention resources. PMID:22819654

  12. Growth Inhibition of Cocoa Pod Rot Fungus Phytophthora palmivora byPseudomonas fluorescence and Bacillus subtilis bacteria

    OpenAIRE

    Sakti Widyanta Pratama; Sri Sukamto; Lis Nur Asyiah; Yeni Vida Ervina

    2013-01-01

    Black pod disease caused by Phytophthora palmivorafungus is one of the important diseases on cocoa crop. Pod rot is the most important disease because it may cause loss of cocoa pod. Until now, the fungal pathogen of cocoa black pod disease is still a crucial problem and there is no fungicide that is really effective against the disease. One alternative to control the cocoa black pod disease is by using biological agents as biofungicide, including utilizing Pseudomonas fluorescenceand Bacillu...

  13. 花椰菜——黑芥体细胞杂交获得抗黑腐病异附加系新材料%New Alien Additon Lines Resistance to Black Rot Generated by Somatic Hybridization Between Cauliflower and Black Mustard

    Institute of Scientific and Technical Information of China (English)

    王桂香; 严红; 曾兴莹; 盛小光; 唐宇; 韩硕; 宗梅; 陆坤; 刘凡

    2011-01-01

    In this study, the asymmetrical somatic hybrids of cauliflower and Brassica nigra and their selfed or backcrossed progenies were analysed using morphological, cytological and molecular methods. Fifty advanced selfing or backcrossing descendants were obtained. Besides 30 lines with an intermediate morphology to that of the parents, there were 20 lines with a nuclear DNA content below 2.24 pg · cell-1 and chromosomes number less than 28 displaying the cauliflower-like morphology. Combining with successive black rot resistance assay, a set of alien additon lines were obtained, in which 12 lines with high resistance, 17 lines being resistant, those accounted for 14% of the total materials tested. Three plants (PFCN29 BC3-3-5, PFCNI6-1 S2BC3-107 and PFCN14-1 S1BC4-123) displayed a more cauliflower-like morphology and high resistance to Xcc strain CH15 were confirmed to have a total set of cauliflower chromosomes added with 2, 7 and 8 B. nigra-derived chromosomes respectively by genomic in situ hybridization (GISH) .%以花椰菜——黑芥体细胞杂种的自交及回交后代为材料,建立了结合抗病性人工接种鉴定,流式细胞仪DNA含量分析,B基因组特异分子标记和染色体原位杂交的大规模群体分析技术,在50份高代自交及回交材料中筛选获得了20份形态学特征偏向花椰菜,30份呈花椰菜一黑芥中间类型的材料。细胞DNA含量检测(FLC)及染色体计数结果表明,偏花椰菜的类型,DNA含量基本在2.24Pg·cell^-1以下,染色体数在28条以下。经连续3年黑腐病病菌人工接种鉴定,获得高抗株系12个,抗性株系17个,占全部受试材料的14%。对其中3个(PFCN29BC3-3-5、PFCNl6-1S2BC3-107和PFCNl4-1S1BC4—123)形态偏花椰菜且高抗黑腐病的植株进行基因组原位杂交,结果显示其分别为花椰菜染色体组附加了2、7和8条黑芥染色体的异附加系材料。这些植株可以用于后续的研究和

  14. 葡萄白腐病、炭疽病、黑痘病、霜霉病和白粉病的识别与防治%ldentification and Control of White Rot, Anthrac-nose, Black Pox, Downy Mildew and Powdery Mildew of Grape

    Institute of Scientific and Technical Information of China (English)

    李婷

    2013-01-01

    Damage symptom and onset characteristics of white rot, anthracnose, black pox,downy mildew and powdery mildew of grape were introduced. More-over, the comprehensive prevention measures were proposed mainly on pre-vention.These diseases should be con-trolled on the basis of enhancing culti-vation management,improving diseasere-sistant capacity of plants, and chemicals should be applied timely at the initial infection stage .The study provided a support for relieving damages of grape diseases, improving yield and quality of grape.%介绍了葡萄白腐病、炭疽病、黑痘病、霜霉病和白粉病的危害症状及发病特点,提出防治这些病害应以预防为主,在加强栽培管理、增强树势、提高树体抗病能力的基础上,在发病初期及时施用化学药剂,以达综合防治的目的。为减轻病害危害,提高葡萄的产量和品质提供了一定的依据。

  15. 利用辣椒疫霉培养滤液体外筛选胡椒抗瘟病无性系研究%In vitro Selection of Black Pepper (Piper nigrum Linn.) Somaclones Resistant to Foot Rot Using Culture Filtrate of Phytophthora capsici

    Institute of Scientific and Technical Information of China (English)

    刘进平; 郑成木

    2004-01-01

    Based on shoot-tip multiplication technique, the application of in vitro selection of black pepper somaclones resistant to foot rot disease caused by fungus Phytophthora capsici was carried out using a large-leaf variety Daye (Lampong Type) which is widely cultivated in Hainan but highly susceptible to P. capsici as explant resources. The results demonstrated that sterilization methods significantly influenced on the toxicity of the culture filtrate of P. capsici. The fungal filtrate toxicity could be maintained using filtrate sterilization by addition of the fungal filtrate into selective medium instead of autoclave sterilization. The survival rate of shoot tips and multiple shoots decreased with the increasing concentrations of the fungal culture filtrate. Some cultures blackened and died finally, and some formed calli or remained dormant. After 2 subcultures onto the same selective medium,microshoots were rooted in vitro and transferred to the greenhouse conditions for screening the resistance to fungus P. capsici. The plants exhibited no external symptoms of the disease during three successive times of resistance assay once two weeks were considered to be resistant. As the concentrations of fungal culture filtrate increased, the total number of regenerated plants obtained declined but the frequencies of plants resistant to P. capsici increased. 1 (1.54%), 4 (20.00%) and 3 (42.86%) disease resistant somaclonal variants were obtained at concentration of 25%, 50% and 75% fungal culture filtrate as selective agents, respectively, with the total number of 8 plants resistant to P. capsici.%在胡椒(Piper nigrum Linn.)茎尖丛生增殖技术的基础上,以印尼大叶种"Lampong Type"无菌实生苗作外植体源,利用辣椒疫霉(Phytophthora capsici)培养滤液对胡椒茎尖及其增殖形成的丛生芽进行体外选择.辣椒疫霉培养滤液的不同灭菌方法对辣椒疫霉培养滤液的毒性影响显著,过滤灭菌方式可以保持辣椒疫霉

  16. 生物有机肥对防治山药根茎腐病和促进山药生长的研究%Effects of Bio-organic Fertilizer on Controlling Root and Stem Rot and Promoting Growth of Yam

    Institute of Scientific and Technical Information of China (English)

    马田田; 杨兴明; 沈其荣; 陈巍

    2013-01-01

    为了探讨生物有机肥(BOF)对山药根茎腐病的防治效果和促生效果,在山药根茎腐病重发地块进行了田间小区试验.结果表明:施用生物有机肥的处理Tl(CK+450 kg/hm2 BOF)、T2(CK+750 kg/hm2 BOF)和T3(CK+1050kg/hm2 BOF)与CK相比,山药根茎腐病病斑的长度分别减小了65.1%、77.2%、78.0%,病斑所占的比例分别下降了67.6%、80.0%、81.7%,对山药根茎腐病有很好的防治效果;山药块茎的鲜重分别增加了15.2%、32.0%、37.1%,块茎长度分别增加了6.0%、11.3%、19.5%,块茎茎粗分别增加了10.9%、23.6%、50.9%,山药产量提高了15.3%、32.2%、37.3%;T1、T2和T3与CK相比,细菌的数量分别增加1.04、1.31、1.41倍、放线菌的数量分别增加1.09、1.18、1.71倍,真菌的数量分别减少了21.9%、46.9%、50.0%,从而改善土壤微生态环境.施用生物有机肥不仅可以明显减少山药根茎腐病的发生,同时对山药有较强的促生效果,具有广阔的应用前景.%Root and stem rot of yam is a main soil-borne disease which severely inhibits the development of yam production industry in China.A field plot experiment was carried out to study the effects of bio-organic fertilizer on the suppression on root and stem rot of yam and plant growth.The results indicated that bio-organic fertilizer could control root and stem rot of yam by reducing the length and the percentage of disease spot.The length of the disease spot of yam tuber in the treatments T1 (CK+450 kg/hm2 BOF),T2 (CK+750 kg/hm2 BOF) and T3 (CK+1050 kg/hm2 BOF) were reduced by 65.1%,77.2% and 78.0%,the percentage of disease spot were reduced by 67.6%,80.0% and 81.7% respectively compared with CK.Bio-organic fertilizer could promote the growth of yam,compared with CK the fresh weight of yam tuber in the treatments T1,T2and T3 were increased by 15.2%,32.0% and 37.1%,the length of yam tuber were increased by 6.0%,11.3% and 19.5

  17. Changes in carbohydrate metabolism in fine roots of the native European black poplar (Populus nigra L.) in a heavy-metal-polluted environment.

    Science.gov (United States)

    Stobrawa, Krzysztof; Lorenc-Plucińska, Gabriela

    2007-02-01

    Effects of copper-smelter-related deposition of heavy metals in the soil on carbohydrate metabolism of fine roots of the native European black poplar were investigated in spring and autumn. Total soluble non-structural carbohydrates in fine roots from trees growing in the polluted habitat were lower than in a control site, but this was directly associated only with a lower raffinose concentration. Neither glucose nor fructose concentrations differed significantly between polluted and unpolluted sites. In contrast, the galactose concentration was higher in the presence of heavy metals, especially in autumn. Also the stachyose concentration was higher in the polluted site, but only in autumn, suggesting it could be an alternative way of detoxification of galactose. No difference between control and polluted stands was observed in sucrose concentration. However, estimates of sucrolytic activity revealed markedly higher activities of sucrose synthase (SuSy), soluble acid (AI) and neutral (NI) invertases in the polluted stand than in the control. In contrast, the estimated glycolytic enzyme activities were not affected by the presence of heavy metals in soil. PMID:17182084

  18. 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.

  19. The effect of crops roots on the content of different form C in black soil%不同作物根系对黑土碳组分及其含量的影响

    Institute of Scientific and Technical Information of China (English)

    耿贵; 汪景宽; 於丽华; 杨云; 邳植

    2011-01-01

    以黑龙江省寒地黑土为研究对象,通过室内培养试验研究了大豆、玉米、甜菜根系对土壤呼吸释放CO2量、水溶性有机碳、微生物量碳和土壤有机碳含量变化的影响.结果表明:大豆、玉米、甜菜根系普遍提高土壤有机碳含量,但是不同作物根系及根系施用量之间还存在一定的差异,大豆根系要好于玉米根系,而玉米根系明显好于甜菜根系.玉米、大豆、甜菜根系提高了土壤呼吸,增加了土壤CO2排放量,提高了土壤微生物量碳含量;而普遍降低了土壤可溶性有机碳含量.%The experiment with three crops ( sugar beet, maize and soybean) roots and black soil was conducted to study the changes of soil respiration and C02 emissions, soil water soluble organic C, soil microorganism biomass C and soil organic C content in soil at different crops roots treatments. The results showed that; soil organic C content was increased after applying of sugar beet, corn, soybean roots to black soil, and the increase were the most to soybean roots, then corn roots, the less increase was sugar beet roots. Soil respiration was enhanced and CO2 emissions were increased after applying of sugar beet, corn, soybean roots to black soil. Soil microorganism biomass C dramatically enhanced in black soil, but soil water soluble organic C was decreased after applying of sugar beet, corn, soybean roots to black soil. These results are different for the different types and quantities of crops roots.

  20. Caracterização de isolados de Xanthomonas campestris pv campestris de sistemas de produção orgânico e reação de brássicas à podridão-negra Characterization of strains of Xanthomonas campestris pv campestris from organic farming systems and reaction of brassicas to black rot

    Directory of Open Access Journals (Sweden)

    Liliana Andréa dos Santos

    2008-12-01

    .3%, resistance to amoxicilin (70%, gentamicin (40.0% and norfloxacin (45.5% and medium sensitivity (44.4% or resistance (44.4% to neomycin. Fifty-five strains of Xcc were resistant to copper sulfate at 50 mg mL-1 and all of them to 200 mg mL-1; 92.22% of the strains showed esterase activity. Strains were grouped in seven similarity groups by the Euclidean analysis-single linkage. The reaction of 14 genotypes of brassicas to strain "B21" of Xcc was also studied. The genotypes significantly differed among them in relation to incubation period, incidence and disease severity. The highest disease severity was recorded on broccoli "Ramoso", cauliflower "Bola de Neve" and "Piracicaba de Verão", and cabbage "Chato de Quintal", classified as highly susceptible to black rot. The Chinese cabbage hybrids "AF 70", "AF 72", "AF 69" and "AF 66" were highly resistant to black-rot, while broccolis "Ramoso" and "Piracicaba Precoce", cauliflower "Piracicaba de Verão" and "Híbrido Cindy" and cabbage "60 Dias" showed intermediate resistance.

  1. 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% .

  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. The Black Black Woman and the Black Middle Class.

    Science.gov (United States)

    Jeffers, Trellie

    1981-01-01

    Reprint of a 1973 article that describes the discrimination that particularly dark-skinned Black women suffer, especially at the hands of a color-conscious Black middle class. Calls for dark women to look to the African appearance and working-class roots as sources of pride and strength. (GC)

  4. 黑豆根尖边缘细胞对盐胁迫的防护效应%Protective Effect of Root Border Cells on Salt Stress in Black Soybean

    Institute of Scientific and Technical Information of China (English)

    邢承华; 郑寨生; 张尚法; 孔向军

    2012-01-01

    The effects of salt stress on root growth,root border cells(RBCs)development,Na+ and K+ content and physiological characteristic in black soybean [ Glycine max ( L. ) Merrill ] were investigated, with RBCs adhered to root tips using a static cultivation method,or with RBCs removed from root tips using a shaking cultivation method. Salt stress treated with 100 and 200 mmol · L-1 NaCl inhibited RBCs development and increased relative electric conductivity and MDA content in roots. Physical removal of RBCs from root tips for 36 h resulted in a more severe inhibition of root elongation and a higher Na+ accumulation in the root tips, the relative electric conductivity and MDA content in roots were also significantly increased when RBCs were removed. The results revealed that RBCs adhered to the root tips tended to regulate the uptake of Na+ and K + , and maintain cell membrane integrity, thereby increased salt tolerance in black soybean seedlings.%采用振荡培养(移除根尖边缘细胞)和静置培养(保持边缘细胞附着在根尖)方法,对比研究盐胁迫对黑豆根系生长和根尖边缘细胞发育、根系Na+、K+含量的影响以及根系生理特性的变化.结果显示:100和200mmol·L-1NaCl处理抑制边缘细胞发育,引起根系相对电导率和MDA含量增加.振荡培养去除根尖边缘细胞处理36 h,黑豆根相对伸长率、根尖K+含量明显低于对应NaCl浓度的静置培养处理,同时根尖Na+含量、相对电导率和MDA含量在去除边缘细胞后显著增加.说明包裹于根尖的边缘细胞通过调节Na+和K+的吸收和维持较高的细胞膜完整性,以适应盐害环境.

  5. 黑豆边缘细胞对干旱胁迫的响应和对根系生理特性的影响%Response of root border cells to drought stress and their effects on physiological characteristics of roots of black soybean seedlings

    Institute of Scientific and Technical Information of China (English)

    邢承华; 吴韶辉; 梅忠; 陈雪; 罗小会

    2012-01-01

    Root border cells and root cap cells secrete mucilage into root rhizosphere which acts as a chemical, physical and biological interface between roots and their surrounding environment. The effects of root border cells (RBCs) and root mucilage on protection of roots from drought stress were carried out by two cultivation methods, a shaking cultivation method to remove RBCs from root tips and a static cultivation method to maintain RBCs adhered to the root tips. Compared to the control, the root border cells nomber are decreased by about 18.1% -21.6% and 28. 8% -30. 4%, respectively under the treatments of the roots with 11% and 22% PEG, while the thicknesses of the mucilage layer around RBCs are increased by about 62. 8% - 140. 7% and 133.8% - 172.7%. These results suggest that the drought stress inhibits RBCs development and enhances mucilage secretion. The physical removal of RBCs from root tips results in a more severe drought-induced inhibition of root elongation, relative electric conductivity and malondialchehyche (MDA) content. The proline content in roots of black soybean with RBCs removed is significantly lower than that in roots with RBCs surrounding. These results suggest that RBCs adhered to the root tips tend to enhance RBCs' mucilage secretion, decrease the damage to root cells, promote root growth, and thereby promote drought tolerance in black soybean seedlings.%以黑豆Glycine max(L.)Merrill为材料,采用静置培养(保持边缘细胞和黏液附着在根尖)和振荡培养(移除边缘细胞及根尖黏液)的方法,比较研究干旱胁迫下黑豆根尖边缘细胞(root border cells,RBCs)产生和黏液分泌以及对根系生理特性的影响。结果表明,与对照相比,11%和22%的聚乙二醇(PEG)处理使RBCs数目分别降低了18.1%~21.6%和28.8%~30.4%,胞外黏液分泌量分别增加了62.8%~140.7%和133.8%~172.7%,表明干旱胁迫抑制了RBCs的发育,增加了RBCs黏液分泌量。移除

  6. 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

  7. 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

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

    Science.gov (United States)

    Basidiomycota (basidiomycetes) make up 32% 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 ...

  9. Black to Black

    DEFF Research Database (Denmark)

    Langkjær, Michael Alexander

    2012-01-01

    Pop musicians performing in black stage costume take advantage of cultural traditions relating to matters black. Stylistically, black is a paradoxical color: although a symbol of melancholy, pessimism, and renunciation, black also expresses minimalist modernity and signifies exclusivity (as...

  10. De Novo Sequencing, Assembly, and Analysis of the Root Transcriptome of Persea americana (Mill.) in Response to Phytophthora cinnamomi and Flooding

    OpenAIRE

    Reeksting, Bianca J.; Coetzer, Nanette; Mahomed, Waheed; Engelbrecht, Juanita; van den Berg, Noëlani

    2014-01-01

    Avocado is a diploid angiosperm containing 24 chromosomes with a genome estimated to be around 920 Mb. It is an important fruit crop worldwide but is susceptible to a root rot caused by the ubiquitous oomycete Phytophthora cinnamomi. Phytophthora root rot (PRR) causes damage to the feeder roots of trees, causing necrosis. This leads to branch-dieback and eventual tree death, resulting in severe losses in production. Control strategies are limited and at present an integrated approach involvin...

  11. Everbearing strawberry cultivars - susceptibility to crown rot

    OpenAIRE

    Parikka, Päivi; Karhu, Saila; Hietaranta, Tarja

    2009-01-01

    Studies on the production of everbearing strawberry cultivars were started at MTT Plant Production Research in 2007. MTT Horticulture makes trials in tunnel and open fields to study the growth, yield and overwintering of cultivars in northern conditions. Resistance to crown rot is also being tested.

  12. Molecular Characterization of Resistant Accessions of Cocoa (Theobroma cocoa L.) to Phytophthora Pod Rot Selected on-Farm in Côte-d’Ivoire.

    Science.gov (United States)

    Cocoa is (Theobroma cacao L.) is a significant agricultural commodity in Côted’Ivoire which ranks 1st in the world cocoa export. Phytophthora pod rot (Ppr)also call Black pod is the most widespread disease of cocoa. Lost due to this disease depends on the species of the pathogen and vary globally fr...

  13. 赞皇枣黑腐病菌拮抗链霉菌的室内多重筛选及发酵条件优化%Screening in vitro of Antagonistic Streptomyces against the Black Rot Disease (Alternaria tenuissima) of Zanhuang Jujube Fruit and Optimization of Fermentation Conditions

    Institute of Scientific and Technical Information of China (English)

    高芬; 李静虹; 王俊宏; 王梦亮

    2015-01-01

    【目的】本研究旨在获得对赞皇枣黑腐病菌具有良好抑制作用的拮抗链霉菌,并对其发酵培养基配方和条件进行优化,以期为进行田间试验和开发生防制剂奠定基础。【方法】以赞皇枣黑腐病优势病原真菌———细极链格孢菌为靶标,采用琼脂块法、牛津杯法和含药平板法对从特殊生境分离获得的10株抗真菌链霉菌进行室内多重筛选,并采用二次回归正交旋转设计和单因素试验对筛选获得的拮抗链霉菌分别进行发酵培养基优化和最佳发酵条件确立。【结果】活体筛选试验中,菌株 AC03、AC04和 AC07表现出了明显的拮抗效果,抑菌圈直径分别为(32.09±1.45),(15.75±1.34),(18.33±0.78)mm;上述3株菌的无菌发酵滤液活性测定表明:菌株AC03、AC07的抑菌圈直径分别为(20.94±0.92)和(23.44±1.63) mm,而菌株 AC04仅为(14.5±0.71) mm;对菌株 AC03和AC07进行无菌发酵滤液的菌丝生长抑制试验,结果表明:菌株 AC07代谢产生的拮抗物质抑菌效果、持效性均优于 AC03。综上可知,菌株 AC07对赞皇枣黑腐病菌的抑菌效果最优。AC07的最优发酵培养基配方为:麦芽糖5.7%,大豆粉2.7%,( NH4)2 SO40.17%,CaCO30.22%,NaCl 0.17%,酵母粉0.2%;最佳发酵条件为:种子液浓度1.5×107~2×108 cfu·mL -1时,接种量2%(V/V),装液量40 mL/250 mL三角瓶,原始pH7.0,发酵温度28℃,发酵时间108 h。【结论】筛选获得的目标拮抗菌 AC07可为开发针对赞皇枣黑腐病的生物农药提供新的原材料,且发酵培养基和条件的优化,提高了目标代谢物的产量,为后续的研究和开发奠定基础。%[Objective]The Zanhuang jujube ( Ziziphus jujuba‘Zanhuang’) fruit black rot disease is one of the most serious fungal pathogens in China. Bio-control of the disease is of great significance to the fruit green production and its sustained efficacy as well as

  14. 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.

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

    Science.gov (United States)

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

    2014-07-01

    Basidiomycota (basidiomycetes) make up 32% 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. PMID:24958869

  16. 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.

  17. Bioremediation of the heavy metal complex dye Isolan Dark Blue 2SGL-01 by white rot fungus Irpex lacteus

    Energy Technology Data Exchange (ETDEWEB)

    Kalpana, Duraisamy [Department of Forest Science and Technology, Institute of Agricultural Science and Technology, Chonbuk National University, Jeonju (Korea, Republic of); Shim, Jae Hong; Oh, Byung-Taek [Division of Biotechnology, Advanced Institute of Environment and Bioscience, College of Environmental and Bioresource Sciences, Chonbuk National University, Iksan (Korea, Republic of); Senthil, Kalaiselvi [Department of Biochemistry, Biotechnology and Bioinformatics, Avinashilingam University for Women, Tamil Nadu (India); Lee, Yang Soo, E-mail: ysoolee@chonbuk.ac.kr [Department of Forest Science and Technology, Institute of Agricultural Science and Technology, Chonbuk National University, Jeonju (Korea, Republic of)

    2011-12-30

    Highlights: Black-Right-Pointing-Pointer Application of the White rot fungus Irpex lacteus. Black-Right-Pointing-Pointer Heavy metal (Cr) conjugated dye. Black-Right-Pointing-Pointer Economic, easy, and rapid. Black-Right-Pointing-Pointer Non toxic nature of the degraded products. Black-Right-Pointing-Pointer Decolorization and degradation at higher concentrations. - Abstract: The present study was conducted to evaluate the decolorization and degradation of the chromium metal complex dye Isolan Dark Blue 2SGL-01 by Irpex lacteus, a white rot lignolytic fungus. I. lacteus effectively decolorized the sulphonated reactive dye at a high concentration of 250 mg/l over a wide range of pH values of 5-9 and temperatures between 20 and 35 Degree-Sign C. Complete (100%) decolorization occurred within 96 h, and I. lacteus demonstrated resistance to the metallic dye. UV-vis spectroscopy, HPLC, GC-MS, and FT-IR analyses of the extracted metabolites confirmed that the decolorization process occurred due to degradation of the dye and not merely by adsorption. GC-MS analysis indicated the formation of 1(2H)-naphthalenone, 3,4-dihydro- and 2-naphthalenol as the main metabolite. ICP analysis demonstrated the removal of 13.49% chromium, and phytotoxicity studies using germinated seeds of Vigna radiata and Brassica juncea demonstrated the nontoxic nature of the metabolites formed during the degradation of Isolan Dark Blue 2SGL-01 dye.

  18. Wood and humus decay strategies by white-rot basidiomycetes correlate with two different dye decolorization and enzyme secretion patterns on agar plates.

    Science.gov (United States)

    Barrasa, José M; Blanco, María N; Esteve-Raventós, Fernando; Altés, Alberto; Checa, Julia; Martínez, Angel T; Ruiz-Dueñas, Francisco J

    2014-11-01

    During several forays for ligninolytic fungi in different Spanish native forests, 35 white-rot basidiomycetes growing on dead wood (16 species from 12 genera) and leaf litter (19 species from 10 genera) were selected for their ability to decolorize two recalcitrant aromatic dyes (Reactive Blue 38 and Reactive Black 5) added to malt extract agar medium. In this study, two dye decolorization patterns were observed and correlated with two ecophysiological groups (wood and humus white-rot basidiomycetes) and three taxonomical groups (orders Polyporales, Hymenochaetales and Agaricales). Depending on the above groups, different decolorization zones were observed on the dye-containing plates, being restricted to the colony area or extending to the surrounding medium, which suggested two different decay strategies. These two strategies were related to the ability to secrete peroxidases and laccases inside (white-rot wood Polyporales, Hymenochaetales and Agaricales) and outside (white-rot humus Agaricales) of the fungal colony, as revealed by enzymatic tests performed directly on the agar plates. Similar oxidoreductases production patterns were observed when fungi were grown in the absence of dyes, although the set of enzyme released was different. All these results suggest that the decolorization patterns observed could be related with the existence of two decay strategies developed by white-rot basidiomycetes adapted to wood and leaf litter decay in the field.

  19. 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.

  20. 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.

  1. 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.

  2. Roots Revisited.

    Science.gov (United States)

    Hughes, Barnabas

    1998-01-01

    Offers historical information about square roots. Presents three different methods--Hero's method, visual method, and remainder method--which can be used to teach the finding of square roots and one method for determining cube roots. (ASK)

  3. 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.

  4. 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.

  5. Influence by physical properties of coal combustion residues (CCRs on dry root productivity of Withania somnifera grown in black cotton soil

    Directory of Open Access Journals (Sweden)

    Bhisham Yadav

    2013-05-01

    Full Text Available In India, presently ~40% Coal Combustion Residues (CCRs generated by burning of pulverized coal at Thermal Power Station is being used for cement, bricks, land reclamation etc. Now a day it has also been considered for agriculture applications. This study, an attempt was made to use of CCRs as soil modifier and micro fertilizer for cultivation of Withania somnifera under two cropping. Results revealed that production of dry root yields of Withania somnifera was found higher in T5 treatment (35.545g and 39.002g per plant as compared to control treatment (T1. It is showed significant (p<0.001% from all the treatments in both the years. The essential elements like Cu, Zn, Fe and Mn were found increasing trends in dry root of Withania somnifera with increase the concentration of CCRs application. This study is found the bulk utilization of CCRs for cultivation of Withania somnifera improved their root yield and chemical quality.

  6. 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.

  7. Rot Morphology and Root-water-uptake Charac teristics of Soybean Seedlings in Response to Different Levels of Phosphorus Supply%不同供磷水平下苗期大豆根系形态特征及吸水特性

    Institute of Scientific and Technical Information of China (English)

    朱向明; 韩秉进

    2014-01-01

    A nutrient solution experiment was conducted to investigate the effect of different levels of phosphorus supply on root morphol -ogy and rootw-ater-uptake characteristics of soybean seedlings .Phosphorus concentration had less effect on root dry weight than on shoot dry weight.Low phosphorus stress increased root dry weight and root /shoot ratio.Phosphorus concentration has significant effect on root morphology of soybean seedlings.Root length,root surface area and root volume initially decreased and then increased with increasing phosphorus concentration.The proportion of root length within 0 ~1 mm diameter was 93%.Daily average root-water-uptake rates per plant increased with increasing phosphorus concentration within 0 ~30μmol· L-1 , but decreased when phosphorus concentration was over 30 μmol· L-1.Thus, the soybean roots would change their root morphology in response to various phosphorus concentrations to some extent.In other words , soybean roots would increase under low phosphorus condition but decrease under high phosphorus condi -tion.%采用水培试验方法,研究了供磷水平对苗期大豆根系形态特征及吸水特性的影响。结果显示:同一时期,供磷水平对根干重的影响小于对地上部干重的影响,缺磷胁迫促进了根干重和根冠比增加;供磷水平对大豆根系形态影响显著,大豆根长、根表面积和根体积基本随供磷水平的升高呈现先减小后增大的趋势,0~1 mm直径范围内根长所占比例最高,约在93%以上;磷素浓度介于0~30μmol· L-1之间时,大豆日平均吸水速率随磷素浓度的增大而增大,当磷素浓度大于30μmol· L-1时,反而随着磷素浓度的增大而减小。由此可见,大豆根系对不同浓度磷素处理具有一定的自我调节能力,表现为“低促高抑”现象,但这种能力是有限的。图4,表1,参12。

  8. Distribuição do sistema radicular de árvores de acáia-negra oriundas de mudas produzidas em diferentes recipientes Influence of seedling production method on the root system distribution of black wattle trees

    Directory of Open Access Journals (Sweden)

    Aline Fagote Paulino

    2003-10-01

    Full Text Available O objetivo deste trabalho foi estudar a distribuição do sistema radicular de árvores de acácia-negra (Acacia mearnsii com 3 anos de idade, provenientes de mudas formadas em diferentes recipientes e instaladas em um Argissolo no Rio Grande do Sul. Os recipientes utilizados foram: laminado, tubete redondo e bandeja de isopor. As avaliações da distribuição das raízes foram feitas pelo método da parede do perfil até 1 m de profundidade, na linha e na entrelinha de plantio. Foram feitas, também, análises físicas do solo: densidade, porosidade total e distribuição de poros. O recipiente usado na formação da muda influenciou o crescimento do sistema radicular da planta no campo. O laminado de madeira apresentou-se superior ao tubete quanto ao comprimento de raízes nas linhas de plantio. As raízes cresceram melhor nas linhas de plantio, onde as condições de densidade e porosidade do solo se encontravam mais adequadas.The purpose of this study was to evaluate the root system distribution of three-year-old black wattle (Acacia mearnsii trees. The plants were originated from seedlings grown in different containers and planted in an Argisol in the state of Rio Grande do Sul, Brazil. The containers used for seedling production were: wood laminated pots, round plastic tubettes and styrofoam trays. The evaluations were carried out using the trench profile method up to 1 m depth on tree rows and inter-rows. The following soil analyses were also carried out: bulk density, total porosity and pore distribution. The type of container used influenced the development of the root system of trees on the field. Wood laminated pots were better than the round tubettes for root length in the tree rows. The roots developed better on the tree rows where soil density and porosity conditions were more adequate.

  9. Production of Ligninolytic Enzymes by White-Rot Fungus Datronia sp. KAPI0039 and Their Application for Reactive Dye Removal

    OpenAIRE

    Pilanee Vaithanomsat; Waraporn Apiwatanapiwat; Oncheera Petchoy; Jirawate Chedchant

    2010-01-01

    This study focused on decolorization of 2 reactive dyes; Reactive Blue 19 (RBBR) and Reactive Black 5 (RB5), by selected white-rot fungus Datronia sp. KAPI0039. The effects of reactive dye concentration, fungal inoculum size as well as pH were studied. Samples were periodically collected for the measurement of color unit, Laccase (Lac), Manganese Peroxidase (MnP), and Lignin Peroxidase (LiP) activity. Eighty-six percent of 1,000 mg L−1 RBBR decolorization was achieved by 2% (w/v) Datronia sp....

  10. 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%.

  11. 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.

  12. 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.

  13. 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.

  14. 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. PMID:27178300

  15. Suppression of seed rot and preemergence of chickpea by seed treatments with fluorescent pseudomonads in Iran.

    Science.gov (United States)

    Ahmadzadeh, M; Sharifi-Tehrani, A

    2006-01-01

    Species of Pythium isolated from rotted chickpea seeds and damped-off seedlings and chickpea soils at experimental field of Agriculture faculty of Tehran University in Karaj area that caused seed rot and preemergence damping-off of chickpea were Pyhium ultimum var. ultimum. One of the most important of soilborne fungal pathogens of the chickpea in Iran is seed rot and preemergence damping-off caused by Pythium ultimum Trow. Consequently, growers can expect as much as > 80% reduction in stand and yield if measures are not taken to control Pythium. Currently, most commercial seeds of chickpea are treated with pesticides. Fluorescent pseudomonads applied to seed are known to reduce soilborne diseases of chickpea caused by Pythium spp. In this study rotted chickpea seeds and diseased seedlings and soil samples were collected from experimental field in Karaj. Soils and roots used as sources of bacteria were collected from field. Fluorescent pseudomonads were isolated by plating samples on S1 and King's Medium B (KMB). Bacteria were preserved in 0.1 M MgSO4 for long-term storage; and NAG (containing 2% glucose) slants and plates at 4 degrees C short-term storage. Of 20 fluorescent pseudomonads isolated on S1 medium, 2 isolates selected for next tests. All strains significantly increased emergence as compared to the infested control in greenhouse trial; isolate Pf-4 consistently provided the best protection against Pythium. Seedling emergence from all bacteria seed treatments was statistically lower than the chemical treatments. All strains significantly increased fresh weight of chickpea as compared to the infested control in greenhouse trial. Seed treatment with metalaxyl were statistically better than captan in sterilized soil. In nonsterilized soil collected from the field artificially infested with P. ultimum, all strains significantly increased fresh weight of chickpea as compared to the infested control in greenhouse trial. Seedling emergence from seed treatment

  16. 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....

  17. Square Root +

    Science.gov (United States)

    Frederiksen, John G.

    1969-01-01

    A rational presentation of the so-called long division method for extracting the square root of a number. Diagrams are used to show relationship of this technique to the binomial theorem. Presentation exposes student to many facets of mathematics in addition to the mechanics of funding square root and cube root. Geometry, algebraic statements,…

  18. 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.

  19. La Nation et ses mémoires The Nation and its Memories. Indian and Black Narratives on Roots and Belonging (Mexico, Columbia

    Directory of Open Access Journals (Sweden)

    Anath Ariel de Vidas

    2011-04-01

    Full Text Available Les grands récits des constructions nationales latino-américaines opposent généralement l’ancestralité des Indiens à l’arrivée postérieure des esclaves noirs. L’analyse des régimes mémoriels de groupes indiens et afrodescendants contemporains, au Mexique et en Colombie, démontre que leur mémoire collective ne s’organise pas forcément en fonction de cette opposition binaire, mais qu’elle s’agence plutôt selon les modalités d’insertion territoriale et d’appartenance régionales. Cet article nuance et réfute donc la pierre de touche que représente cette catégorie classificatrice d’autochtonie et propose une vision contextualisée des dispositifs mémoriels, dans le temps et l’espace social. Ces dispositifs articulent des dimensions culturelles et politiques pour forger des configurations identitaires originales et non déterminées par l’origine ethnique ou raciale des groupes concernés.The main narratives of Latin-American national constructions generally oppose the ancestrality of the Indians to the later arrival of black slaves. This analysis of the memorial systems of Indian groups and contemporary afro-descendants, in Mexico and in Colombia, shows that their collective memory does not organize itself necessarily according to this binary opposition but rather according to specific modalities of territorial integration and of regional belonging. This article qualifies and refutes the validity of this classifying category of autochthony and proposes a contextualized vision of the memorial mechanisms in social time and space. These mechanisms articulate cultural and political dimensions to forge original identitarian configurations not determined by the ethnic or racial origin of the concerned groups.

  20. Genes of resistance to carrot soft rot in Daucus carota germplasm

    International Nuclear Information System (INIS)

    Erwinia carotovora is a casual agent of soft rot in the carrot. This disease causes severe root losses in the crop, mainly during post-harvest storage but also in the field in the late growing season. Of the many cultivars screened in our department between 1988 and 1990, we found none that was resistant. Consequently, we started to look for sources of resistance genes among wild Daucus carota subspecies. Resistant plants were used for callus production, which will constitute the material for in vitro selection. Resistance to Erwinia carotovora is rather rare. Proof of this is research on the potato, which has been conducted for many years and where the only source of resistance that has been found is the wild species Solanumb brevidens. 3 refs

  1. 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.

  2. Aplicação superficial de diferentes fontes de corretivos no crescimento radicular e produtividade da aveia preta Surface application by different lime source in root growth and yield of black oat

    Directory of Open Access Journals (Sweden)

    Juliano Corulli Corrêa

    2008-08-01

    Full Text Available Em solos ácidos, a prática da calagem superficial favorece o crescimento radicular, principalmente na superfície do solo, bem como a produtividade das culturas em condições normais de precipitação pluviométrica. Entretanto, pouco se sabe sobre a adoção desta prática e suas eventuais ações, no solo e nas plantas, em relação a outras fontes de corretivos. O objetivo do trabalho foi avaliar o efeito da aplicação superficial de diferentes corretivos nos atributos químicos do solo, no crescimento radicular, da parte aérea e na produtividade da aveia preta. O trabalho foi desenvolvido em campo sobre Latossolo Vermelho distrófico, durante o ano agrícola de 2004, dois anos após a aplicação superficial dos corretivos, no sistema plantio direto. Os tratamentos constituíram da aplicação superficial de calcário dolomítico, escoria de aciaria - E, lama cal - Lcal, lodo de esgoto centrifugado - LC e sem aplicação de corretivo, em delineamento em blocos casualizados com quatro repetições. A aplicação superficial de calcário, escória de aciaria, lama cal, lodo de esgoto centrifugado permitiu o aumento nos valores de pH, no teor de Ca, na maior disponibilidade de P e na redução dos teores de Al no solo. O crescimento do sistema radicular, o desenvolvimento da parte aérea e a produtividade da aveia preta foram incrementados com a aplicação superficial dos corretivos de acidez no sistema plantio direto.Surface lime application to an acid soil under no-till system and normal rainfall conditions increases yield and crop root growth near the soil surface, but the effects of lime sources like flue dust, sewage sludge and aqueous lime have not been fully investigated . The experiment aimed to evaluate the effects of surface application of different lime sources on soil chemical attributes of a clayey, dystrophic Oxisol and black oat root growth and yield under a no-till system. Evaluations were conducted two years after the

  3. 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.

  4. CHARACTERIZATION OF WOOD DECAY BY ROT FUNGI USING COLORIMETRY AND INFRARED SPECTROSCOPY

    OpenAIRE

    Mírian de Almeida Costa; Alexandre Florian da Costa; Tereza Cristina Monteiro Pastore; Jez Willian Batista Braga; Joaquim Carlos Gonçalez

    2011-01-01

    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 w...

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

    OpenAIRE

    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, and New Zealand, were identical in an analysis based on 96 polymorphic bands from seven primer combinations. Leather rot isolates of strawberry could not be distinguished from isolates from other...

  6. 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

  7. 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.

  8. Root doctors as providers of primary care.

    Science.gov (United States)

    Stitt, V J

    1983-07-01

    Physicians in primary care recognize that as many as 65 percent of the patients seen in their offices are there for psychological reasons. In any southern town with a moderate population of blacks, there are at least two "root doctors." These root doctors have mastered the power of autosuggestion and are treating these patients with various forms of medication and psychological counseling. This paper updates the practicing physician on root doctors who practice primary care.

  9. 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.

  10. 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.

  11. 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.

  12. 日本落叶松人工林心腐率的调查%Investigation on Heart Rot Rate of Larix kaemp f eri

    Institute of Scientific and Technical Information of China (English)

    贾明; 李永生; 李宏; 马颖; 姜海; 王永祥

    2013-01-01

    Heart rot of Larix kaempferi above 40-year-old were investigated .Result shows that :root rot of Larix kaempferi will become increasingly serious with the increase of forest age ;heart rot rate of 40 ,50 & 60-year-old Larix kaempferi are 39% ,69% ,84% ,respectively ;influence of heart rot on the growth of Larix kaempferi is great ;growth of tree height & diameter decrease significantly ;the quality & value of trees were seriously affected . Therefore ,final felling regeneration should be conducted on Larix kaempferi with more tree rings to avoid huge los-ses by too sever heart rot to the economy .%通过对40年生以上的日本落叶松(Larix kaempferi)人工林心腐的调查研究,结果表明,日本落叶松随林龄的增长,根部腐朽会越来越重,40年时腐蚀率达39%,50年达69%,60年达84%。心腐对日本落叶松的生长影响很大,树高和胸径生长量明显下降,同时也严重地影响林木的质量和产值。所以,对林龄较大的日本落叶松应及时主伐更新,避免因心腐过重给经济带来巨大的损失。

  13. Root patterning

    NARCIS (Netherlands)

    Scheres, Ben; Laskowski, Marta

    2016-01-01

    The mechanisms that pattern lateral root primordial are essential for the elaboration of root system architecture, a trait of key importance for future crop breeding. But which are most important: periodic or local cues? In this issue of Journal of Experimental Botany (pages 1411-1420), Kircher a

  14. 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

    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...... in richness were observed between samples associated with diseased and healthy roots. Health status and field both had significant effects on fungal community structures in roots, whereas only field had significant effects on communities in rhizosphere and bulk soils. Indicator species analysis across...... 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...

  15. Black Consciousness

    Science.gov (United States)

    Hraba, Joseph; Siegman, Jack

    1974-01-01

    Black militancy is treated as an instance of class consciousness with criteria and scales developed to measure black consciousness and "self-placement" into black consciousness. These dimensions are then investigated with respect to the social and symbolic participation in the ideology of the black movement on the part of a sample of black…

  16. EVIDENCE FOR CLEAVAGE OF LIGNIN BY A BROWN ROT FUNGUS

    Science.gov (United States)

    Biodegradation by brown-rot fungi is quantitatively one of the most important fates of lignocellulose in nature. It has long been thought that these fungi do not degrade lignin significantly, and that their activities on this abundant aromatic biopolymer are limited to minor oxidative modifications....

  17. Production and degradation of oxalic acid by brown rot fungi

    International Nuclear Information System (INIS)

    Our results show that all of the brown rot fungi tested produce oxalic acid in liquid as well as in semisolid cultures. Gloeophyllum trabeum, which accumulates the lowest amount of oxalic acid during decay of pine holocellulose, showed the highest polysaccharide-depolymerizing activity. Semisolid cultures inoculated with this fungus rapidly converted 14C-labeled oxalic acid to CO2 during cellulose depolymerization. The other brown rot fungi also oxidized 14C-labeled oxalic acid, although less rapidly. In contrast, semisolid cultures inoculated with the white rot fungus Coriolus versicolor did not significantly catabolize the acid and did not depolymerize the holocellulose during decay. Semisolid cultures of G. trabeum amended with desferrioxamine, a specific iron-chelating agent, were unable to lower the degree of polymerization of cellulose or to oxidize 14C-labeled oxalic acid to the extent or at the rate that control cultures did. These results suggest that both iron and oxalic acid are involved in cellulose depolymerization by brown rot fungi

  18. 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...

  19. Genome Sequence of Mushroom Soft-Rot Pathogen Janthinobacterium agaricidamnosum

    OpenAIRE

    Graupner, Katharina; Lackner, Gerald; Hertweck, Christian

    2015-01-01

    Janthinobacterium agaricidamnosum causes soft-rot disease of the cultured button mushroom Agaricus bisporus and is thus responsible for agricultural losses. Here, we present the genome sequence of J. agaricidamnosum DSM 9628. The 5.9-Mb genome harbors several secondary metabolite biosynthesis gene clusters, which renders this neglected bacterium a promising source for genome mining approaches.

  20. Calibrating echelle spectrographs with Fabry-Pérot etalons

    Science.gov (United States)

    Bauer, F. F.; Zechmeister, M.; Reiners, A.

    2015-09-01

    Context. Over the past decades hollow-cathode lamps have been calibration standards for spectroscopic measurements. Advancing to cm/s radial velocity precisions with the next generation of instruments requires more suitable calibration sources with more lines and fewer dynamic range problems. Fabry-Pérot interferometers provide a regular and dense grid of lines and homogeneous amplitudes, which makes them good candidates for next-generation calibrators. Aims: We investigate the usefulness of Fabry-Pérot etalons in wavelength calibration, present an algorithm to incorporate the etalon spectrum in the wavelength solution, and examine potential problems. Methods: The quasi-periodic pattern of Fabry-Pérot lines was used along with a hollow-cathode lamp to anchor the numerous spectral features on an absolute scale. We tested our method with the HARPS spectrograph and compared our wavelength solution to the one derived from a laser frequency comb. Results: The combined hollow-cathode lamp/etalon calibration overcomes large distortion (50 m/s) in the wavelength solution of the HARPS data reduction software. The direct comparison to the laser frequency comb shows differences of only 10 m/s at most. Conclusions: Combining hollow-cathode lamps with Fabry-Pérot interferometers can lead to substantial improvements in the wavelength calibration of echelle spectrographs. Etalons can provide economical alternatives to the laser frequency comb, especially for smaller projects.

  1. Examining African self-consciousness and Black racial identity as predictors of Black men's psychological well-being.

    Science.gov (United States)

    Pierre, Martin R; Mahalik, James R

    2005-02-01

    This study investigated African self-consciousness and Black racial identity as predictors of psychological distress and self-esteem for Black men. One hundred thirty Black men from a college and community sample completed the African Self-Consciousness Scale, the Racial Identity Attitude Scale-B, the Symptom Checklist 90-Revised, and the Coopersmith Self-Esteem Inventory. Canonical correlation analysis found 2 significant roots with the 1st root indicating that Black men whose attitudes reflected Preencounter and Immersion racial identity attitudes and who do not resist against anti-African/Black forces reported greater psychological distress and less esteem. Results from the 2nd root suggested that Black men whose attitudes reflect greater Internalization racial identity attitudes, greater resistance to anti-African/Black forces, and less identification with Blacks reported greater self-esteem. PMID:15727493

  2. Control of lettuce bottom rot by isolates of Trichoderma spp

    Directory of Open Access Journals (Sweden)

    Zayame Vegette Pinto

    2014-06-01

    Full Text Available Bottom rot, caused by Rhizoctonia solani AG 1-IB, is an important disease affecting lettuce in Brazil, where its biological control with Trichoderma was not developed yet. The present study was carried out with the aim of selecting Trichoderma isolates to be used in the control of lettuce bottom rot. Forty-six Trichoderma isolates, obtained with baits containing mycelia of the pathogen, were evaluated in experiments carried out in vitro and in vivo in a greenhouse in two steps. In the laboratory, the isolates were evaluated for their capabilities of parasitizing and producing toxic metabolic substances that could inhibit the pathogen mycelial growth. In the first step of the in vivo experiments, the number and the dry weight of lettuce seedlings of the cultivar White Boston were evaluated. In the second step, 12 isolates that were efficient in the first step and showed rapid growth and abundant sporulation in the laboratory were tested for their capability of controlling bottom rot in two repeated experiments, and had their species identified. The majority of the isolates of Trichoderma spp. (76% showed high capacity for parasitism and 50% of them produced toxic metabolites capable of inhibiting 60-100% of R. solani AG1-IB mycelial growth. Twenty-four isolates increased the number and 23 isolates increased the dry weight of lettuce seedlings inoculated with the pathogen in the first step of the in vivo experiments.In both experiments of the second step, two isolates of T. virens, IBLF 04 and IBLF 50, reduced the severity of bottom rot and increased the number and the dry weight of lettuce seedlings inoculated with R. solani AG1-IB. These isolates had shown a high capacity for parasitism and production of toxic metabolic substances, indicating that the in vitro and in vivo steps employed in the present study were efficient in selecting antagonists to be used for the control of lettuce bottom rot.

  3. Root resorption

    DEFF Research Database (Denmark)

    Kjaer, Inger

    2014-01-01

    -an ectodermal tissue layer (Malassez′s epithelium), a middle layer-composed by the collagen-mesodermal tissue layer, and an innermost root-close innervation layer. Abnormalities in one of these tissue layers are thought to cause inflammatory processes in the periodontal membrane comparable to inflammatory...... formerly been demonstrated how demyelinization of the myelin sheaths in the peripheral nerves close to the root provoke resorption. Accordingly, conditions affecting these tissue layers can be associated not only with different morphologies but also with general symptoms and diseases (e.g., ectodermal...... 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...

  4. Diversity study on Sclerotinia trifoliorum Erikks., the causal agent of clover rot in red clover crops (Trifolium pratense L.).

    Science.gov (United States)

    Vleugels, T; Baert, J; De Riek, J; Heungens, K; Malengier, M; Cnops, G; Van Bockstaele, E

    2010-01-01

    Since the 16th century, red clover has been an important crop in Europe. Since the 1940s, the European areal of red clover has been severely reduced, due to the availability of chemical fertilizers and the growing interest in maize. Nowadays there is a growing interest in red clover again, although some setbacks still remain. An important setback is the low persistence of red clover crops. Clover rot, caused by the ascomycete fungus Sclerotinia trifoliorum Erikss., is a major disease in Europe and reduces the persistence of red clover crops severely. The fungus infects clover plants through ascospores in the autumn, the disease develops during the winter and early spring and can kill many plants in this period. In early spring, black sclerotia, serving as surviving bodies, are formed on infected plants. Sclerotia can survive up to 7 years in the soil (Ohberg, 2006). The development of clover rot is highly dependent on the weather conditions: a humid fall, necessary for the germination of the ascospores and an overall warm winter with short periods of frost are favourable for the disease. Cold and dry winters slow the mycelial growth down too much and prevent the disease from spreading. Clover rot is difficult to control and completely resistant red clover varieties have yet to be developed. Because of the great annual variation in disease severity, plant breeders cannot use natural infection as an effective means to screen for resistant material. Breeding for resistant cultivars is being slowed down by the lack of a bio-test usable in breeding programs. When applying artificial infections, it is necessary to have an idea of the diversity of the pathogen. A diverse population will require resistance screening with multiple isolates. The objective of this research is to investigate the genetic diversity among isolates from the pathogen S. trifoliorum from various European countries. We assessed diversity using a species identification test based on the sequence of

  5. Black Droplets

    CERN Document Server

    Santos, Jorge E

    2014-01-01

    Black droplets and black funnels are gravitational duals to states of a large N, strongly coupled CFT on a fixed black hole background. We numerically construct black droplets corresponding to a CFT on a Schwarzchild background with finite asymptotic temperature. We find two branches of such droplet solutions which meet at a turning point. Our results suggest that the equilibrium black droplet solution does not exist, which would imply that the Hartle-Hawking state in this system is dual to the black funnel constructed in \\cite{Santos:2012he}. We also compute the holographic stress energy tensor and match its asymptotic behaviour to perturbation theory.

  6. Control of Postharvest Fusarium Rot and Trichothecium Rot in Harvested Muskmelon (cv. Yindi) by Harpin

    Institute of Scientific and Technical Information of China (English)

    GE Yong-hong; BI Yang; LI Mei; LI Xuan

    2005-01-01

    Preharvest and postharvest application of Harpin was evaluated for its ability to induce resistance in muskmelon fruit and control rots. Preharvest treatments were 30 mg L-1, 60 mg L-1 Harpin or 1 mg L-1 Imazalil either 1 week or 1 day before harvest.The CK was untreated. Fruit were then inoculated with Fusarium semitectum or Trichothecium roseum 48 h after harvest,and stored at 23 ± 1℃, RH (relative humidity) 50-60% for 4 d. All treatments were effective in reducing the lesion area with 60 mg L-1 Harpin the most effectively. No treatments inhibited infection rate. Postharvest treatment was fruit dips of 30 mg L-1, 60 mg L-1 Harpin, 0.1 mg L-1 Imazalil. Fruit were inoculated with F. semitectum or T. roseum 24, 72, 120 or 168 h after treatment, and stored at 23 ± 1 ℃, RH 50-60% for 4 days. All treatments were effective in reducing the lesion area with 60 mg L-1 Harpin the most effectively. No treatments inhibited the infection rate. Postharvest Harpin treatment induced the peroxidase activity increase, peroxidase activity reached maximum after 8 d and the activation lasted at least 10 d.

  7. Black Eye

    Science.gov (United States)

    ... eyesight if not treated. If both eyes are black after a head injury, it could signify a skull fracture or other serious injury. Next Black Eye Symptoms Related Ask an Ophthalmologist Answers How ...

  8. 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.

  9. Korrektur von Rot- bzw. Grünanomalie mittels Farbfilter

    OpenAIRE

    Junger, Barbara

    2009-01-01

    Zielsetzung Farbensehen ist ein physiologisches Vermögen basierend unter anderem auf Pigmentgenen, erzeugten Photopigmenten und deren Absorptionsspektren. Im Falle von Störungen des Rot- und Grüngenes resultiert fehlerhaftes Farbensehen im Sinne von anomaler Trichromasie, Dichromasie oder Blauzapfenmonochromasie. Zur Therapie der anomalen Trichromasie wurden korrigierende Farbfilter (Coloryte) mit Spezialbeschichtung entwickelt, deren Einfluss auf das Farbensehen Gegenstand dieser Studie w...

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

    OpenAIRE

    Nityananda Chakraborty; Balen Nandi

    2015-01-01

    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 du...

  11. Stabilization of lignin peroxidases in white rot fungi by tryptophan.

    OpenAIRE

    Collins, P. J.; Field, J. A.; Teunissen, P; Dobson, A D

    1997-01-01

    Supplementation of various cultures of white rot fungi with tryptophan was found to have a large stimulatory effect on lignin peroxidase activity levels. This enhancement was greater than that observed in the presence of the lignin peroxidase recycling agent veratryl alcohol. Using reverse transcription-PCR, we found that tryptophan does not act to induce lignin peroxidase expression at the level of gene transcription. Instead, the activity enhancement observed is likely to result from the pr...

  12. 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 ...

  13. Fusarium rot of onion and possible use of bioproduct

    OpenAIRE

    Klokočar-Šmit Zlata; Lević Jelena; Maširević Stevan; Grozdanović-Varga Jelica; Vasić Mirjana; Aleksić Svjetlana

    2008-01-01

    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, express...

  14. Biological control of Black Pod Disease and Seedling Blight of cacao caused by Phytophthora Species using Trichoderma from Aceh Sumatra

    Science.gov (United States)

    The cocoa tree, Theobroma cacao L., suffers large yield losses in Aceh Indonesia to the disease black pod rot, caused by Phytophthora spp. Despite having the largest area under cacao production in Sumatra, farmers in the Aceh region have low overall production because of losses to insect pests and b...

  15. Black Holes

    Science.gov (United States)

    Luminet, Jean-Pierre

    1992-09-01

    Foreword to the French edition; Foreword to the English edition; Acknowledgements; Part I. Gravitation and Light: 1. First fruits; 2. Relativity; 3. Curved space-time; Part II. Exquisite Corpses: 4. Chronicle of the twilight years; 5. Ashes and diamonds; 6. Supernovae; 7. Pulsars; 8. Gravitation triumphant; Part III. Light Assassinated: 9. The far horizon; 10. Illuminations; 11. A descent into the maelstrom; 12. Map games; 13. The black hole machine; 14. The quantum black hole; Part IV. Light Regained: 15. Primordial black holes; 16. The zoo of X-ray stars; 17. Giant black holes; 18. Gravitational light; 19. The black hole Universe; Appendices; Bibliography; Name index; Subject index.

  16. Eradicant and curative treatments of hexanal against peach brown rot

    Directory of Open Access Journals (Sweden)

    Juliana Silveira Baggio

    2014-02-01

    Full Text Available Brown rot, caused by Monilinia spp. , is one of the most important peach (Prunuspersica (L. Batsch diseases and the main cause of postharvest losses. Currently, alternative methods for postharvest disease control, such as the use of volatiles, are under investigation. The objective of this study was to determine the effects of hexanal on the in vitro development of Monilinia fructicola and M. laxa and on monocyclic components of brown rot on peaches. To evaluate the effect on pathogen development in vitro, a single dose of 215 µL of liquid hexanal was placed on glass jars in closed plastic containers (4.3 L at the moment of fungi transfer, 24 or 48 h after transferring to Petri dishes. After hexanal application, the Petri dishes were kept inside the containers that were closed for 24 h at 20 ºC. Mycelial growth was measured seven days after hexanal removal. For in vivo assays, inoculated fruits were kept in closed plastic containers, and hexanal was applied at the moment of fruit inoculation or 24 hours thereafter. The monocyclic components infection frequency, expressed as brown rot incidence, lesion diameter and lesion sporulation, were assessed daily for seven days. Overall, hexanal was more effective in inhibiting mycelial growth when applied at the moment of pathogen transfer. Hexanal did not prevent pathogen infection, but reduced lesion diameter and completely inhibited spore production on the fruit for both treatments. Hexanal provides a promising alternative for chemical control and can be used in postharvest handling systems.

  17. Root canal

    Science.gov (United States)

    Endodontic therapy ... the root of a tooth. Generally, there is pain and swelling in the area. The infection can ... You may have some pain or soreness after the procedure. An over-the-counter anti-inflammatory drug, such as ibuprofen or naproxen, can help relieve ...

  18. Detection of potato brown rot and ring rot by electronic nose: from laboratory to real scale.

    Science.gov (United States)

    Biondi, E; Blasioli, S; Galeone, A; Spinelli, F; Cellini, A; Lucchese, C; Braschi, I

    2014-11-01

    A commercial electronic nose (e-nose) equipped with a metal oxide sensor array was trained to recognize volatile compounds emitted by potatoes experimentally infected with Ralstonia solanacearum or Clavibacter michiganensis subsp. sepedonicus, which are bacterial agents of potato brown and ring rot, respectively. Two sampling procedures for volatile compounds were tested on pooled tubers sealed in 0.5-1 L jars at room temperature (laboratory conditions): an enrichment unit containing different adsorbent materials (namely, Tenax(®) TA, Carbotrap, Tenax(®) GR, and Carboxen 569) directly coupled with the e-nose (active sampling) and a Radiello(™) cartridge (passive sampling) containing a generic Carbograph fiber. Tenax(®) TA resulted the most suitable adsorbent material for active sampling. Linear discriminant analysis (LDA) correctly classified 57.4 and 81.3% total samples as healthy or diseased, when using active and passive sampling, respectively. These results suggested the use of passive sampling to discriminate healthy from diseased tubers under intermediate and real scale conditions. 80 and 90% total samples were correctly classified by LDA under intermediate (100 tubers stored at 4°C in net bag passively sampled) and real scale conditions (tubers stored at 4°C in 1.25 t bags passively sampled). Principal component analysis (PCA) of sensorial analysis data under laboratory conditions highlighted a strict relationship between the disease severity and the responses of the e-nose sensors, whose sensitivity threshold was linked to the presence of at least one tuber per sample showing medium disease symptoms. At intermediate and real scale conditions, data distribution agreed with disease incidence (percentage of diseased tubers), owing to the low storage temperature and volatile compounds unconfinement conditions adopted. PMID:25127615

  19. Antagonistic effect of fungi from Scots pine stump roots against Heterobasidion annosum and Armillaria ostoyae

    Directory of Open Access Journals (Sweden)

    Hanna Kwaśny

    2014-08-01

    Full Text Available The study presents quantitative and qualitative aspects of fungal colonization of the 2-year-old stump roots of the 30- and 49-year-old Scots pines, and biotic relations between fungi inhabiting the stump roots and major agent s of butt and root rot in Poland, i.e.: H. annosum and A. ostoyae. Compared to the live roots, the increase in density of fungi communities as well as the frequency of the fungi antagonistic towards H. annosum and A. ostoyae, particularly of Trichoderma species. in pine stump roots resulted in the increase of the suppressive effect of these communities towards both pathogens, studied in vitro. This finding may suggest a stronger resistance of pine stump roots to H. annosum and A. ostoyae what under forest conditions may be the example of natural control of both pathogens.

  20. EFFECTS OF PHYTOPHTHORA ROOT ROT AND METALAXYL TREATMENT ON THE YIELD OF SOME FORAGE BRASSICA SPECIES

    OpenAIRE

    Karakaya, Aziz; KOCH, D.W.; Gray, F. A.

    1995-01-01

    Three forage Brassica species were evaluated for their growth and adaptability to the Rocky Mountain region. Brassicas were grown in fields infested with a Phytophthora disease previoıısly observed on kale (Brassica oleracea var. Acephala) Metalaxyl treatmıent did not affect Brassica yields signifıcantly. Although pest problems were detected, Brassica crops tolerated low temperatures and produced excellent yields ( up to 9.90 Mg/ha). The Phytophthora isolates from Brassica, which were identif...

  1. Impact of Heterobasidion spp. root rot in conifer trees and assessment of stump treatment

    OpenAIRE

    Wang, Liying

    2012-01-01

    In the thesis four studies were conducted to understand the impact of Heterobasidion spp. on Picea abies, Pinus sylvestris, and Larix × eurolepis in southern Sweden, and the efficacy of stump treatment against infection in order to economically assess control measures. The ability of secondary spread of H. parviporum inoculated on Norway spruce stumps created at precommercial thinning (PCT) was investigated. Stumps with a minimum diameter of 2.5 cm were able to transfer infection to adjace...

  2. Nematode Control Related to Fusarium Wilt in Soybean and Root Rot and Zinc Deficiency in Corn

    OpenAIRE

    Minton, N. A.; Parker, M. B.; Sumner, D. R.

    1985-01-01

    Nematode and disease problems of irrigated, double-cropped soybean and corn, and zinc deficiency of corn were investigated. Ethylene dibromide, phenamiphos, and aldicarb were equally effective for controlling nematodes and increasing yields of corn planted minimum-till and soybean planted in a moldboard plow prepared seedbed. The residual effects on yields of nematicides applied to the preceeding crop occurred during 3 years for soybean and 1 year for corn. Fusarium wilt symptoms of soybean t...

  3. 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.

  4. 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 ...

  5. Isolation and Characterization of Trichoderma spp. for Antagonistic Activity Against Root Rot and Foliar Pathogens.

    Science.gov (United States)

    Kumar, Krishna; Amaresan, N; Bhagat, S; Madhuri, K; Srivastava, R C

    2012-06-01

    Trichoderma, soil-borne filamentous fungi, are capable of parasitising several plant pathogenic fungi. Twelve isolates of Trichoderma spp. isolated from different locations of South Andaman were characterized for their cultural, morphological and antagonistic activity against soil borne and foliar borne pathogens. The sequencing of these isolates showed seven different species. The isolates revealed differential reaction patterns against the test pathogens viz., Sclerotium rolfsii, Colletotrichum gloeosporioides and C. capsici. However, the isolates, TND1, TWN1, TWC1, TGD1 and TSD1 were most effective in percentage inhibition of mycelial growth of test pathogens. Significant chitinase and β-1,3-glucanase activities of all Trichoderma isolates has been recorded in growth medium. T. viride was found with highest chitinase whereas T. harzianum was recorded with highest β-1,3-glucanase activities. PMID:23729873

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

    OpenAIRE

    Montaser Fawzy ABDEL-MONAIM; Mamdoh Ewis ISMAIL

    2010-01-01

    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 pathogeni...

  7. 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.

  8. Black Culture

    Directory of Open Access Journals (Sweden)

    Angela Khristin Brown

    2013-07-01

    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life. 

  9. Locally Finite Root Supersystems

    OpenAIRE

    YOUSOFZADEH, Malihe

    2013-01-01

    We introduce the notion of locally finite root supersystems as a generalization of both locally finite root systems and generalized root systems. We classify irreducible locally finite root supersystems.

  10. Temporal changes in wood crystalline cellulose during degradation by brown rot fungi

    DEFF Research Database (Denmark)

    Howell, Caitlin; Hastrup, Anne Christine Steenkjær; Goodell, Barry;

    2009-01-01

    The degradation of wood by brown rot fungi has been studied intensely for many years in order to facilitate the preservation of in-service wood. In this work we used X-ray diffraction to examine changes in wood cellulose crystallinity caused by the brown rot fungi Gloeophyllum trabeum, Coniophora...

  11. First report of brown rot on apple fruit caused by Monilinia fructicola in the United States

    Science.gov (United States)

    Brown rot, caused by Monilinia fructicola (G. Wint.) Honey, is the most devastating disease of stone fruits in North America resulting in significant economic losses. The fungus has been recently reported to cause pre and postharvest brown rot on apple fruit in Germany, Italy, and Serbia. However, M...

  12. 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...

  13. 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

  14. Sorghum pathology and biotechnology - A fungal disease perspective: Part II. Anthracnose, stalk rot, and downy mildew

    Science.gov (United States)

    Foliar diseases and stalk rots are among the most damaging diseases of sorghum in terms of lost production potential, thus commanding considerable research time and expenditure. This review will focus on anthracnose, a fungal disease that causes both foliar symptoms and stalk rots along with the st...

  15. Evaluation of Pseudomonas syringae Strain ESC11 for Biocontrol of Crown Rot and Anthracnose of Banana

    Science.gov (United States)

    Pseudomonas syringae strain ESC11, and 250 'g/ml each of thiabendazole (TBZ) and imazalil reduced crown rot of banana caused by a Fusarium sp. by 0-88% and 73-88%, respectively, in laboratory experiments. ESC11 alone did not significantly reduce rot, mold, or anthracnose in most field trials. TBZ an...

  16. 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

  17. 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...

  18. The ovipositional response of the Australian sheep blowfly, Lucilia cuprina, to fleece-rot odours.

    Science.gov (United States)

    Watts, J E; Merritt, G C; Goodrich, B S

    1981-10-01

    The ovipositional response of Lucilia cuprina flies to odours emanating from fleece-rot lesions of greasy wool in which Pseudomonas aeruginosa bacteria proliferated, was studied. Fractionation of the fleece-rot odours was carried out by bubbling the volatile components through hydrochloric acid and sodium hydroxide solutions to remove basic odours and acidic odours respectively. It was found that the acidic/neutral odours of fleece-rot wool, when perfused into wet, greasy wool stimulated L. cuprina to oviposit. On the other hand, the basic/neutral odours of fleece-rot wool were virtually unattractive to the gravid fly. Similarly, the acidic/neutral odours emanating from fleece-rot lesions of clean wool from which the non-fibre components, wax, suint and epithelial debris, had been removed by scouring, were found to be unattractive to the gravid fly in choice tests. PMID:7337595

  19. 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.

  20. 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.

  1. 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

  2. Growth Inhibition of Cocoa Pod Rot Fungus Phytophthora palmivora byPseudomonas fluorescence and Bacillus subtilis bacteria

    Directory of Open Access Journals (Sweden)

    Sakti Widyanta Pratama

    2013-08-01

    Full Text Available Black pod disease caused by Phytophthora palmivorafungus is one of the important diseases on cocoa crop. Pod rot is the most important disease because it may cause loss of cocoa pod. Until now, the fungal pathogen of cocoa black pod disease is still a crucial problem and there is no fungicide that is really effective against the disease. One alternative to control the cocoa black pod disease is by using biological agents as biofungicide, including utilizing Pseudomonas fluorescenceand Bacillus subtilis bacteria. The research was done by isolation of P. palmivora from infected pods of Kaliwining Experimental Station to obtain pure cultures of fungus and by multiplication of P. fluorescence and B. subtilis. Antagonist test was performed by inoculating P. palmivora into a petri dish in a distance of 3 cm from the edge. P. fluorescenceand B. Subtilis were inoculated into petridishes in three days after the fungal treatment. Control was inoculated with isolate of P. palmivora only. Fungal growth was measured everyday by measuring radius of fungal colonies first time 24 hours after inoculation. Growth of Phytophthora palmivora in the two treatmens were used to calculate the percentage of inhibition. The results of this study indicated that P. fluorescence and B. subtiliswere able to inhibit fungal growth of P. palmivora. Both bacterial antagonists had the same effectiveness in inhibiting the growth of P. palmivora fungus based on the percentage of inhibition and effectiveness criteria. Based on the results of translucent zones indicated that B. subtiliswas more powerfull in inhibiting growth of P. Palmivora compared to P. fluorescence. Key words: Black pod disease of cocoa, biological control, Phytophthora palmivora, Pseudomonas fluorescence, Bacillus subtilis

  3. Monilinia species causing brown rot of peach in China.

    Directory of Open Access Journals (Sweden)

    Meng-Jun Hu

    Full Text Available In this study, 145 peaches and nectarines displaying typical brown rot symptoms were collected from multiple provinces in China. A subsample of 26 single-spore isolates were characterized phylogenetically and morphologically to ascertain species. Phylogenetic analysis of internal transcribed spacer (ITS regions 1 and 2, glyceraldehyde-3-phosphate dehydrogenase (G3PDH, β-tubulin (TUB2 revealed the presence of three distinct Monilinia species. These species included Monilinia fructicola, Monilia mumecola, and a previously undescribed species designated Monilia yunnanensis sp. nov. While M. fructicola is a well-documented pathogen of Prunus persica in China, M. mumecola had primarily only been isolated from mume fruit in Japan. Koch's postulates for M. mumecola and M. yunnanensis were fulfilled confirming pathogenicity of the two species on peach. Phylogenetic analysis of ITS, G3PDH, and TUB2 sequences indicated that M. yunnanensis is most closely related to M. fructigena, a species widely prevalent in Europe. Interestingly, there were considerable differences in the exon/intron structure of the cytochrome b (Cyt b gene between the two species. Morphological characteristics, including spore size, colony morphology, lesion growth rate, and sporulation, support the phylogenetic evidence suggesting the designation of M. yunnanensis as a new species. A new multiplex PCR method was developed to facilitate the detection of M. yunnanensis and differentiation of Monilinia spp. causing brown rot of peach in China.

  4. 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.

  5. Efficient xylose fermentation by the brown rot fungus Neolentinus lepideus.

    Science.gov (United States)

    Okamoto, Kenji; Kanawaku, Ryuichi; Masumoto, Masaru; Yanase, Hideshi

    2012-02-10

    The efficient production of bioethanol on an industrial scale requires the use of renewable lignocellulosic biomass as a starting material. A limiting factor in developing efficient processes is identifying microorganisms that are able to effectively ferment xylose, the major pentose sugar found in hemicellulose, and break down carbohydrate polymers without pre-treatment steps. Here, a basidiomycete brown rot fungus was isolated as a new biocatalyst with unprecedented fermentability, as it was capable of converting not only the 6-carbon sugars constituting cellulose, but also the major 5-carbon sugar xylose in hemicelluloses, to ethanol. The fungus was identified as Neolentinus lepideus and was capable of assimilating and fermenting xylose to ethanol in yields of 0.30, 0.33, and 0.34 g of ethanol per g of xylose consumed under aerobic, oxygen-limited, and anaerobic conditions, respectively. A small amount of xylitol was detected as the major by-product of xylose metabolism. N. lepideus produced ethanol from glucose, mannose, galactose, cellobiose, maltose, and lactose with yields ranging from 0.34 to 0.38 g ethanol per g sugar consumed, and also exhibited relatively favorable conversion of non-pretreated starch, xylan, and wheat bran. These results suggest that N. lepideus is a promising candidate for cost-effective and environmentally friendly ethanol production from lignocellulosic biomass. To our knowledge, this is the first report on efficient ethanol fermentation from various carbohydrates, including xylose, by a naturally occurring brown rot fungus. PMID:22226194

  6. Resistance of Brassica rapa L. and B. napus L. to black rot and leaf spot pathogens

    OpenAIRE

    IGNATOV A.N.; A.M. Artemyeva; Yu.V. Chesnokov; POLITYKO V.A.; E.V. Matveeva; A.A. Oraevskiy; Schaad, N. W.

    2011-01-01

    Изучали географическое и таксономическое распределение расоспецифической устойчивости к фитопатогенным ксантомонадам среди образцов Brassica rapa и B. napus. Выявлено, что устойчивые к расе 4 Xanthomonas campestris Pam. (Dow.) (Xcc) подвиды B. rapa в основном сконцентрированы в Центральной Азии и Японии. Впервые обнаружены доноры комплексной устойчивости B. rapa ко всем исследованным расам патогена и источники устойчивости к расам Xcc 1 и Xcc 3 среди образцов B. rapa и B. napus....

  7. Black psyllium

    Science.gov (United States)

    ... block your throat or esophagus and may cause choking. Do not take this product if you have ... take enough water. Otherwise, black psyllium might cause choking. Take at least 150 mL water for each ...

  8. Black tea

    Science.gov (United States)

    ... product containing black tea extract plus green tea extract, asparagus, guarana, kidney bean, and mate along with a combination of kidney bean pods, garcinia, and chromium yeast for 12 weeks does not reduce body weight ...

  9. Black tea

    Science.gov (United States)

    ... heartburn, dizziness, ringing in the ears, convulsions, and confusion. Also, people who drink black tea or other ... glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide ( ...

  10. Re-imagining South Africa: Black Consciousness, radical Christianity and the New Left, 1967 – 1977

    OpenAIRE

    Macqueen, Ian Martin

    2011-01-01

    This thesis places Black Consciousness in comparative perspective with progressive politics in South Africa in the late 1960s and the 1970s. It argues that the dominant scholarly focus on Black Consciousness, which is passed over as a ‘stage’ in the Black struggle against white supremacy, insufficiently historicises the deeper roots, and the wider resonances and ideological contestations of the Black Consciousness movement. As they refined their political discourse, Black Consciousness activi...

  11. The Differences in Root Traits and Photosynthesis of Wheat in Lime Concretion Black Soil under Long-term Different Fertilization Patterns%长期不同施肥模式下砂姜黑土小麦根系和光合的差异性研究

    Institute of Scientific and Technical Information of China (English)

    张向前; 曹承富; 张存岭; 乔玉强; 杜世州; 李玮; 赵竹; 陈欢

    2016-01-01

    In order to clarify the difference in the effects of long-term single fertilization model,we studied the effects of five kinds of long-term (34 years)located fertilization models on root traits,photosynthesis and yield of wheat in lime concretion black soil.The results showed that the root traits of CK(no fertilizer application)was the worst,the total root length,total root surface area,total root volume and total root tips of MNPK(mixed application of organic and chemical fertilizer with the same amount of nitrogen)and HMNPK(mixed application of organic and chemical fertilizer with the larger amount of nitrogen)were significant higher than that of NPK(application of single chemical fertilizer)and M(application of single organic fertilizer),in addition,the differences between NPK and M in total root surface area,average root diameter and total root volume were insignificant.When compared to long-term application of single chemical fertilizer(NPK)and organic fertilizer(M),the treatment of long-term mixed ap-plication of organic and chemical fertilizer(MNPK and HMNPK)could help to enhance the top-three leaves width and length of wheat.At booting stage,the photosynthetic rate,stomatal conductance and transpiration rate of MNPK were the highest,but there was no significant difference with HMNPK;at middle of filling stage(MNPK and HMNPK happen lodging),the photosynthetic characteristics of NPK and M were better than that of MNPK and HMNPK,and the photosynthetic characteristics of MNPK was also better than that of HMNPK(the most serious lodging).At boo-ting stage,compared to long-term application of single chemical fertilizer and organic fertilizer,the treatment of mixed application of organic and chemical fertilizer could help to improve wheat chlorophyll fluorescence parame-ters;At middle of filling stage,the chlorophyll fluorescence parameters of M was perform the best,and the ΦpsⅡ , Fv /Fm,ETR,qP of MNPK were significant higher than that of HMNPK.Total root length

  12. Control of Ralstonia Solanacearum The Causal Agent of Brown Rot in Potato Using Essential Oils

    International Nuclear Information System (INIS)

    Five essential oils, namely peppermint (Mentha piperita L.), caraway (Carium carvum L.), fennel (Foeniculum vulgare Mill.), lemongrass (Cymbopogon citratus Staph.) and thyme (Thymus vulgaris), were used separately against Ralstonia solanacearum; the causal agent of brown rot in potato. The most two effective oils (peppermint and thyme) were used in vitro and in vivo after testing their effects on potato tubers buds germination. Peppermint inhibited buds germination but thyme have no effects on buds germination. In vivo, the control of brown rot using thyme oil in glass house experiment reduced the percentage of brown rot infection to 30.6% and reduced the severity of disease from 5 to 3.

  13. 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.

  14. 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...

  15. Evaluación de estrés hídrico en plantas de fresa a raíz desnuda Evaluation of water stress on bare-root strawberry plants

    Directory of Open Access Journals (Sweden)

    César Gutiérrez Vaca

    Full Text Available En el estudio realizado se determinó el tiempo disponible antes de aplicar riego vía goteo, después de plantar fresa a raíz desnuda en suelo acolchado con humedad a punto de marchitamiento permanente, sin poner en riesgo de muerte a la planta. Con el propósito de diseñar una trasplantadora para plantas a raíz desnuda que opere sobre suelos secos acolchados. Se analizaron 4 tratamientos de riego; se regó una hora antes del trasplante, al momento del trasplante, 1 y 2 horas después del trasplante. El experimento se llevó a cabo en noviembre de 2007 en la comunidad "El Copal", municipio de Irapuato, Guanajuato, México; donde la altura sobre el nivel del mar es de 1 720 m; el suelo de la región es de textura arcillo-limoso cuya humedad de punto de marchitamiento permanente es alrededor de 18%. El plástico utilizado fue de color blanco al exterior, negro al interior con 30 µm de espesor. Se determinó que es viable aplicar el riego al momento de realizar el trasplante y hasta dos horas después sin exponer la integridad de la planta, con 95% de certidumbre. Se concluye que es posible realizar el trasplante mecanizado de plantas de fresa a raíz desnuda sobre suelo acolchado seco al ambiente, lo que permitirá que la trasplantadora en cuestión pueda operar.This study determined the time available before irrigating, after planting bare-root strawberry plants in soil cushioned with moisture before rotting permanently, without risking the plant's life. This, in order to design a grafting device for bare-root plants that runs on dry cushioned soils.Four irrigation treatments were analyzed; one was applied an hour before transplanting, another when transplanting, and 1 and 2 hours afterwards. The experiment was carried out in November 2007 in the town of "El Copal", in the municipality of Irapuato, Guanajuato, Mexico; the location's height is 1 720 masl; the soil is silty clay loam and the rotting point humidity is around 18%. The plastic

  16. 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).

  17. 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.

  18. Black holes

    CERN Document Server

    Chrúsciel, P T

    2002-01-01

    This paper is concerned with several not-quantum aspects of black holes, with emphasis on theoretical and mathematical issues related to numerical modeling of black hole space-times. Part of the material has a review character, but some new results or proposals are also presented. We review the experimental evidence for existence of black holes. We propose a definition of black hole region for any theory governed by a symmetric hyperbolic system of equations. Our definition reproduces the usual one for gravity, and leads to the one associated with the Unruh metric in the case of Euler equations. We review the global conditions which have been used in the Scri-based definition of a black hole and point out the deficiencies of the Scri approach. Various results on the structure of horizons and apparent horizons are presented, and a new proof of semi-convexity of horizons based on a variational principle is given. Recent results on the classification of stationary singularity-free vacuum solutions are reviewed. ...

  19. 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.

  20. Biodegradation of hazardous waste using white rot fungus: Project planning and concept development document

    International Nuclear Information System (INIS)

    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 ampersand 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

  1. Effect of sterilization on mineralization of straw and black carbon

    DEFF Research Database (Denmark)

    Bobul'ská, Lenka; Bruun, Sander; Fazekašová, Danica

    2013-01-01

    The study was aimed at investigating the role of microorganisms in the degradation of BC (black carbon). CO evolution was measured under sterilized and non-sterilized soil using BC and straw amendments. Black carbon and straw were produced from homogenously C labelled roots of barley (Hordeum vul...... abiotic source must also be present perhaps abiotic mineralization of labile BC components....

  2. Hendersonia Creberrima, the cause of soft brown rot of mango in South Africa

    International Nuclear Information System (INIS)

    A soft brown rot of mangoes in South Africa, is especially severe in export fruit kept in cold storage for prolonged periods. At present mangoes can be exported most economically by sea. This involves storage at 110C for approximately 21 days. Unfortunately, these appear to be ideal conditions for the development of soft brown rot. Losses as high as 80% were recorded. The South African fungus agrees in morphology and cultural characters with Hendersonia Creberrima

  3. Zwalczanie zgnilizny powodowanej przez grzyby z rodzaju Penicillium [Control of Penicillium apple rot

    Directory of Open Access Journals (Sweden)

    H. Borecka

    2015-06-01

    Full Text Available Control of Pezicula spp. fungi reduced Penicillium apple rot. The Penicillium apple rot process began slowly under the modified atmosphere of 5% CO2 and 3% O2. The lower concentration of Benlate – 0.05% did not influence this fungicide's effectiveness, The lower concentration– 0.05% of Topsin M decreased the effectiveness of this fungicide. The resistant strains of Penicillium spp. to benzimidazole fungicides under laboratory conditions were obtained.

  4. 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.

  5. Experimental and Numerical Characterization of a Hybrid Fabry-Pérot Cavity for Temperature Sensing

    Directory of Open Access Journals (Sweden)

    Aitor Lopez-Aldaba

    2015-04-01

    Full Text Available A hybrid Fabry-Pérot cavity sensing head based on a four-bridge microstructured fiber is characterized for temperature sensing. The characterization of this cavity is performed numerically and experimentally in the L-band. The sensing head output signal presents a linear variation with temperature changes, showing a sensitivity of 12.5 pm/°C. Moreover, this Fabry-Pérot cavity exhibits good sensitivity to polarization changes and high stability over time.

  6. Prospects for Inhibition of lignin degrading enzymes to control ganoderma white rot of oil palm

    OpenAIRE

    Paterson, R. R. M.; Meon, Sariah; Abidin, M. A. Zainal; Lima, Nelson

    2008-01-01

    Oil palm (OP) is prone to a rot by the fungus Ganoderma which may be capable of being controlled by enzyme inhibitors. Palm oil is used in the production of vegetable oil for foods, cosmetics, pharmaceuticals and, most recently, biodiesel. However, the fundamental process of the disease as “white rot” has been ignored by researchers. White rot fungi are capable of degrading lignin ultimately to carbon dioxide and water: Celluloses become available as nutrients for the fungus. One potential co...

  7. Potato brown rot incidence and severity under different management and amendment regimes in different soil types

    OpenAIRE

    Messiha, N.A.S.; Bruggen, van, C.; Diepeningen, van, A.D.; Vos; 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 organic agriculture, it was timely to compare the effects of organic and conventional management and various amendments on brown rot development in different soils (type: sand or clay; origin: Egypt ...

  8. Evaluation of fungicide programs for management of Botrytis bunch rot of grapes: 2009 field trial

    OpenAIRE

    Janousek, Christopher N; Bay, Ian S.; Herche, Ryan W; Gubler, W D

    2009-01-01

    Botrytis bunch rot is an important grapevine disease in California. Twenty eight fungicide programs were evaluated for control of bunch rot in a field experiment in a Chardonnay (clone 4) vineyard in the Carneros region of Napa Valley, California during 2009. Four fungicide applications were made from bloom to harvest with the final application made just prior to heavy rainfall. Disease was rated three weeks following the final application. Disease developed rapidly during the month of Octobe...

  9. Evaluation of fungicide programs for management of Botrytis bunch rot of grapes: 2010 field trial

    OpenAIRE

    Bay, Ian S.; Eynard, James; Gubler, W D

    2010-01-01

    Bunch rot of grapes is caused by Botrytis cinerea, a fast-growing pathogen infecting numerous crops of commercial value. Bunch rot can potentially lead to a reduction in the yield and quality of table, raisin, and wine grapes, with high economic losses in some locations or years (Flaherty et al. 1992). Botrytis overwinters as sclerotia in mummified berries on the ground or on canes. The disease can first appear as shoot blight following frequent spring rains; flowers can become infected durin...

  10. Losses due to lenticel rot are an increasing concern for Kern County potato growers

    OpenAIRE

    Farrar, Jim; Nunez, Joe; Davis, R. M.

    2009-01-01

    In recent years, lenticel rot of potato tubers, caused by the bacterium Erwinia carotovora subsp. carotovora, has become an economically important postharvest disease for Kern County growers. Disease symptoms are sunken and rotted tissue surrounding tuber lenticels, which develop after harvest and packing. In the field, the bacterium also causes Erwinia early dying, characterized by wilt and progressive necrosis of leaves, eventually resulting in potato plant death. This study confirms Erwini...

  11. Polycyclic aromatic hydrocarbon degradation by the white rot fungus Bjerkandera sp. strain BOS55.

    OpenAIRE

    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 anthracene and the ligninolytic indicator dye Poly R-478 by the white rot fungus, were studied. Two parameters were identified as the most important PAH oxidation rate-limiting factors: the hydrogen peroxide production r...

  12. Zwalczanie zgnilizny powodowanej przez grzyby z rodzaju Penicillium [Control of Penicillium apple rot

    OpenAIRE

    H. Borecka

    2015-01-01

    Control of Pezicula spp. fungi reduced Penicillium apple rot. The Penicillium apple rot process began slowly under the modified atmosphere of 5% CO2 and 3% O2. The lower concentration of Benlate – 0.05% did not influence this fungicide's effectiveness, The lower concentration– 0.05% of Topsin M decreased the effectiveness of this fungicide. The resistant strains of Penicillium spp. to benzimidazole fungicides under laboratory conditions were obtained.

  13. X-ray computed tomography uncovers root-root interactions: quantifying spatial relationships between interacting root systems in three dimensions

    Directory of Open Access Journals (Sweden)

    Alexander Martin Paya

    2015-04-01

    Full Text Available Research in the field of plant biology has recently demonstrated that inter- and intra-specific interactions belowground can dramatically alter root growth. Our aim was to answer questions related to the effect of inter- vs. intra-specific interactions on the growth and utilization of undisturbed space by fine roots within three dimensions (3D using micro X-ray computed tomography. To achieve this, Populus tremuloides (quaking aspen and Picea mariana (black spruce seedlings were planted into containers as either solitary individuals, or inter-/intra-specific pairs, allowed to grow for two months, and 3D metrics developed in order to quantify their use of belowground space. In both aspen and spruce, inter-specific root interactions produced a shift in the vertical distribution of the root system volume, and deepened the average position of root tips when compared to intra-specifically growing seedlings. Inter-specific interactions also increased the minimum distance between root tips belonging to the same root system. There was no effect of belowground interactions on the radial distribution of roots, or the directionality of lateral root growth for either species. In conclusion, we found that significant differences were observed more often when comparing controls (solitary individuals and paired seedlings (inter- or intra-specific, than when comparing inter- and intra-specifically growing seedlings. This would indicate that competition between neighboring seedlings was more responsible for shifting fine root growth in both species than was neighbor identity. However, significant inter- vs. intra-specific differences were observed, which further emphasizes the importance of biological interactions in competition studies.

  14. 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.

  15. 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.

  16. Soft rot decay capabilities and interactions of fungi and bacteria from fumigated utility poles

    International Nuclear Information System (INIS)

    The objectives were to (1) identify microfungi and bacterial associates isolated from fumigated southern pine poles from EPRI project RP 1471-72, (2) study the soft-rot capabilities of predominant fungi, and (3) study interactions among microorganisms in relation to wood decay. Methods for identification followed standard techniques using morphological and physiological criteria. Soft-rot by microfungi alone and with bacteria was determined as weight loss and anatomical examination of wood blocks using light microscopy and limited electron microscopy. Acinetobacter calcoaceticus was the predominant bacterium. Twenty-one species of microfungi were identified including four new species. A book entitled IDENTIFICATION MANUAL FOR FUNGI FROM UTILITY POLES IN THE EASTERN UNITED STATES was published. An improved soft-rot test was devised. Fifty-one of 84 species (60%) of microfungi from poles tested were soft-rot positive; that is much greater than previously reported. Three types of anatomical damage of wood of pine or birch caused by soft-rot fungi were described. Interaction tests showed that, in some cases, there was a strong synergism between bacteria and fungi in causing weight loss, but results were inconsistent. Although soft rot is often most apparent under conditions of very high moisture, intermediate moisture levels appear to be optimal, as with basidiomycete decayers

  17. 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

  18. Effects of eco-biochar fertilizer on soil renovating and control of tobacco root-knot nematode and black shank%利用生态炭肥修复土壤防治烟草根结线虫病与黑胫病

    Institute of Scientific and Technical Information of China (English)

    张涵; 焦永吉; 赵世民; 赵云波; 刘涛; 蒋士君

    2016-01-01

    The occurrence and epidemic of tobacco root-knot nematode and black shank closely relate to soil micro-ecology environment. To study the effects on soil micro-ecology environment and control efficiency of eco-biochar fertilizers, field experiments including soil renovating, soil micro-ecology environment improving and tobacco root-knot nematode and black shank controlling with eco-biochar fertilizer were conducted in Luoyang dryland tobacco fields where tobacco was planted for four consecutive years and tobacco root-knotnematode and black shank occurred seriously. Furthermore, the control efficiencies of eco-biochar fertilizers, plant-based nematicide, fosthiazate (chemical pesticide) and avermectins (biological pesticide) were compared. The results showed that: 1) The amounts of bacteria and actinomycetes and the invertase activity in soil were significantly increased by the application of eco-biochar fertilizer M-20 (300 kg/ha), eco-biochar fertilizer EC-10 (150 kg/ha) and plant-based nematicide (30 kg/ha) during transplanting. The effects of M-20, EC-10 and plant-based nematicide on soil micro-ecology environment renovating were better than those of fosthiazate (30 kg/ha) and avermectins (45 kg/ha). 2) At late harvesting stage, the treatments in the order of control efficiency to tobacco root-knot nematode were EC-10 (80.53%)> plant-based nematicide (75.69%)> M-20 (75.46%)> fosthiazate(61.92%)> avermectins(26.71%). Meanwhile, the control efficiencies of M-20, EC-10 and plant-based nematicide to black shank were significantly higher than those of other treatments. Therefore, eco-biochar fertilizers can renovate soil and control tobacco root-knot nematode and black shank effectively.%烟草根结线虫病与黑胫病的发生流行与土壤微生态环境关系密切。为明确生态炭肥对土壤微生态的调节作用及防病效果,选择洛阳烟区连作4年且根结线虫病和黑胫病危害严重的旱地烟田,进行了生态炭肥修复土壤、

  19. Fischer Black

    OpenAIRE

    Robert C. Merton; Myron S. Scholes

    2013-01-01

    ReprintThis article was originally published by Wiley for the American Finance Association (Merton RC, Scholes MS. 1995. Fischer Black. J. Finance 50(5):1359–70). It is reprinted with permission from John Wiley and Sons © 1995. Reference formatting was updated to facilitate linking.

  20. Pharmacognostic and phytochemical investigation of root of Solanum nigrum Linn.: An ethnomedicinally important herb

    OpenAIRE

    Chandrashekhar Yuvaraj Jagtap; Pradeep Kumar Prajapati; Harisha Chinnappa Rudrappa; Shukla, Vinay J.

    2013-01-01

    Background: Roots of Solanum nigrum Linn. (Solanaceae), commonly known as black night shade (Kakamachi), is traditionally used in the treatment of worms and abdominal pain. Until date no scientific evaluation has been reported on its roots. Aim: The present study deals with the microscopical, histochemical, physicochemical, fluorescence analysis, preliminary phytochemical and chromatographic study of roots of S. nigrum L. Materials and Methods: Thin sections of fresh root were used for the mi...

  1. 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.

  2. Revised Phylogeny and Novel Horizontally Acquired Virulence Determinants of the Model Soft Rot Phytopathogen Pectobacterium wasabiae SCC3193

    OpenAIRE

    Johanna Nykyri; Outi Niemi; Patrik Koskinen; Jussi Nokso-Koivisto; Miia Pasanen; Martin Broberg; Ilja Plyusnin; Petri Törönen; Liisa Holm; Minna Pirhonen; E Tapio Palva

    2012-01-01

    Soft rot disease is economically one of the most devastating bacterial diseases affecting plants worldwide. In this study, we present novel insights into the phylogeny and virulence of the soft rot model Pectobacterium sp. SCC3193, which was isolated from a diseased potato stem in Finland in the early 1980s. Genomic approaches, including proteome and genome comparisons of all sequenced soft rot bacteria, revealed that SCC3193, previously included in the species Pectobacterium carotovorum, can...

  3. Root canal irrigants

    OpenAIRE

    Kandaswamy Deivanayagam; Venkateshbabu Nagendrababu

    2010-01-01

    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...

  4. Black Pete through the Eyes of Dutch Children.

    Science.gov (United States)

    Mesman, Judi; Janssen, Sofie; van Rosmalen, Lenny

    2016-01-01

    The traditional figure of Black Pete seen during the December festivities around Sinterklaas (the Dutch Santa Claus) in the Netherlands has sparked fierce debates about his racial stereotypical characteristics and his potentially negative effects on children's opinions about black people. The Black Pete phenomenon has even been discussed by the United Nations Committee on the Elimination of Racial Discrimination, resulting in a report urging the Netherlands to eliminate this form of racial stereotyping. The adult debate about Black Pete is clearly important, but Sinterklaas is essentially a children's holiday. Surprisingly, there have never been any systematic studies to examine children's views on Black Pete. The current study is the first to do so. In a sample of 201 children aged 5-7 years, we collected free descriptions of Black Pete, asked children to group him in relation to other figures, and to assign characteristics to him and comparison figures. The results showed that (1) Children are clearly aware of Black Pete's skin color and subordinate status; (2) Children associate Black Pete more with clowns than with black people; (3) Children evaluate Black Pete very positively, but the positive characteristics do not generalize to their evaluation of black people. The findings illustrate the deep-rooted childhood origins of many Dutch people's affection for Black Pete and their lack of awareness of his relation to racial stereotypes. This explains the resistance to changing the Black Pete figure and the slowness of the change process on this front. PMID:27322583

  5. 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

  6. FTIR and XPS analysis of the changes in bamboo chemical structure decayed by white-rot and brown-rot fungi

    International Nuclear Information System (INIS)

    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.

  7. 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.

  8. black cat

    Institute of Scientific and Technical Information of China (English)

    杜铁梅

    2016-01-01

    The black cat is a masterpiece of short fiction of Poe. He successfully solved the problem of creating of the horror effect by using scene description, symbol, repetition and first-person narrative methods. And created a complete and unified mysterious terror, achieved the effect of shocking. This paper aims to discuss the mystery in-depth and to enrich the research system in Poe’s novels.

  9. White-rot fungal growth on sugarcane lignocellulosic residue

    Energy Technology Data Exchange (ETDEWEB)

    Rolz, C.; Leon, R. de; Arriola, M.C. de; Cabrera, S. de

    1987-03-01

    Twelve white-rot fungi were grown in solid state culture on sugarcane chips previously fermented by yeast employing the EX-FERM process. The lignocellulosic sugarcane residue had 12.5% permanganate lignin and 81.3% holocellulose. After 5 to 6 weeks at 20/sup 0/C, all fungi produced a solid residue which had a lower in vitro dry matter enzymatic digestibility than the original bagasse, with the exception of Coriolus versicolor which showed a slight increase of 0.6 units. Four fungi produced a residue with higher soluble solids that the original sample. Lignin losses were rather similar for all fungi tested, an average value of 38.64% of the original value was obtained. About the same amount of hemicellulose was degreaded, 32.22%. Most fungi showed a preference for hemicellulose hydrolysis over cellulose degradation. The two fungi that showed greater cellulolytic activity were Sporotrichum pulverulentum and Dichomitus squalens. No appreciable dry matter losses were detected for Agrocybe aergerita and Flammulina velutipes.

  10. Production of Ligninolytic Enzymes by White-Rot Fungus Datronia sp. KAPI0039 and Their Application for Reactive Dye Removal

    Directory of Open Access Journals (Sweden)

    Pilanee Vaithanomsat

    2010-01-01

    Full Text Available This study focused on decolorization of 2 reactive dyes; Reactive Blue 19 (RBBR and Reactive Black 5 (RB5, by selected white-rot fungus Datronia sp. KAPI0039. The effects of reactive dye concentration, fungal inoculum size as well as pH were studied. Samples were periodically collected for the measurement of color unit, Laccase (Lac, Manganese Peroxidase (MnP, and Lignin Peroxidase (LiP activity. Eighty-six percent of 1,000 mg L−1 RBBR decolorization was achieved by 2% (w/v Datronia sp. KAPI0039 at pH 5. The highest Lac activity (759.81 UL−1 was detected in the optimal condition. For RB5, Datronia sp. KAPI0039 efficiently performed (88.01% decolorization at 2% (w/v fungal inoculum size for the reduction of 600 mg L−1 RB5 under pH 5. The highest Lac activity (178.57 UL−1 was detected, whereas the activity of MnP and LiP was absent during this hour. The result, therefore, indicated that Datronia sp. KAPI0039 was obviously able to breakdown both reactive dyes, and Lac was considered as a major lignin-degradation enzyme in this reaction.

  11. 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.

  12. 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. PMID:26671414

  13. Developmental and Metabolic Plasticity of White-Skinned Grape Berries in Response to Botrytis cinerea during Noble Rot1[OPEN

    Science.gov (United States)

    Collins, Thomas S.; Vicente, Ariel R.; Doyle, Carolyn L.; Ye, Zirou; Allen, Greg; Heymann, Hildegarde

    2015-01-01

    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. PMID:26450706

  14. Comparing lignocellulose physiochemistry after decomposition by brown rot fungi with distinct evolutionary origins.

    Science.gov (United States)

    Kaffenberger, Justin T; Schilling, Jonathan S

    2015-12-01

    Among wood-degrading fungi, lineages holding taxa that selectively metabolize carbohydrates without significant lignin removal (brown rot) are polyphyletic, having evolved multiple times from lignin-removing white rot fungi. Given the qualitative nature of the 'brown rot' classifier, we aimed to quantify and compare the temporal sequence of carbohydrate removal among brown rot clades. Lignocellulose deconstruction was compared among fungi using distinct plant substrates (angiosperm, conifer, grass). Specifically, aspen, pine and corn stalk were harvested over a 16-week time series from microcosms containing Gloeophyllum trabeum, Fomitopsis pinicola, Ossicaulis lignatilis, Fistulina hepatica, Serpula lacrymans, Wolfiporia cocos or Dacryopinax sp. After quantifying plant mass loss, a thorough compositional analysis was complemented by a saccharification test to determine wood cell wall accessibility. Mass loss and accessibility varied depending on fungal decomposer and substrate, and trajectories of loss for hemicellulosic components and cellulose differed among plant tissue types. At any given stage of decomposition, however, lignocellulose accessibility and the fraction remaining of carbohydrates and lignin within a plant tissue type were generally the same, regardless of fungal isolate. This suggests that the sequence of plant component removal at this typical scale of characterization is shared among these brown rot lineages, despite their diverse genomes and secretomes. PMID:25181619

  15. 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.

  16. Root Graded Lie Superalgebras

    OpenAIRE

    Yousofzadeh, Malihe

    2015-01-01

    We define root graded Lie superalgebras and study their connection with centerless cores of extended affine Lie superalgebras; our definition generalizes the known notions of root graded Lie superalgebras.

  17. Using Square Roots

    Science.gov (United States)

    Wilson, William Wynne

    1976-01-01

    This article describes techniques which enable the user of a comparatively simple calculator to perform calculations of cube roots, nth roots, trigonometric, and inverse trigonometric functions, logarithms, and exponentials. (DT)

  18. 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 are predominant in stone fruit culture, whereas M. fructigena is i

  19. 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...

  20. First report of Lasiodiplodia theobromae causing inflorescence blight and fruit rot of longan (Dimocarpus longan L.) in Puerto Rico

    Science.gov (United States)

    Longan is a tropical fruit tree in the Sapindaceae family. During a disease survey from 2008 to 2010, fruit rot and inflorescence blight (rotting of the rachis, rachilla and flowers) were observed at the USDA-ARS Research Farm in Isabela, Puerto Rico. Tissue sections (1 mm2) of diseased inflorescenc...

  1. 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.

  2. 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.

  3. 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

  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. 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.

  6. Evaluation of the bioremediation ability of the isolated white rot fungus on the textile effluents

    Directory of Open Access Journals (Sweden)

    Indira Priyadarsini* R

    2012-08-01

    Full Text Available Every one contributes to the environmental pollution by theiractivities either directly or indirectly and it is our moral responsibility to uncover a solution in order to come out of it also. Hence an attempt was made to isolate a white rot fungus with better remediation ability. The white rot fungus was isolated from decay wood sample and identified as Trametes hirsuta by molecular identification methods. The assessment of the bioremediation ability of the isolated organism was done with four textile effluent samples and the physico-chemical parameters namely colour, pH, TSS, TDS, COD, BOD, Total Hardness, level of Calcium, Magnesium, Chloride and Sulphate were evaluated. The change in the initial pH values of the four textile effluents after treatment with the isolated organism was not significant. All the other parameters were found to be reduced from their respective initial level after treatment with the isolated white rot fungus.

  7. 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.

  8. Using the Resistograph®to distinguish different types of wood rot on living silver fir in Molise (Italy

    Directory of Open Access Journals (Sweden)

    Lasserre B

    2010-10-01

    Full Text Available he study was performed in two silver-fir forests (Abies alba Mill. located in Alto Molise, Province of Isernia: Collemeluccio, near Pescolanciano and Abeti Soprani near Capracotta. The aim of this work was to distinguish different types of wood rot on living silver fir individuals by using the Resistograph® (IML-RESI E400, a device that allows to estimate the variation of wood density by measuring the resistance to micro-perforation. The occurrence of different types of wood rot (white rot and brown rot in living trees was pointed out and discriminated by the device. In the detected deteriorated zones, fungal pathogens and decomposers were isolated and identified, causing either white (Phellinus hartigii, Ganoderma adspersum, Heterobasidion abietinum and Armillaria ostoyae or brown rot (Fomitopsis pinicola.

  9. Screening preharvest/postharvest strategies to prevent fruit rot decay.

    Science.gov (United States)

    Vorstermans, B; Creemers, P

    2007-01-01

    In fruit growing preharvest sprayings in the orchard are mainly applied to protect fruit from decaying. Next to multisite fungicides (captan, thiram, tolylfluanid) the most commonly used products recognized for the Belgium market are Bellis (pyraclostrobin & boscalid) and the combination of Topsin M (thiophanate-methyl) and Frugico (diethofencarb). In general the spraying schedule varies depending on weather conditions (infection risk), preharvest interval of available fungicides, fruitgrower and cultivar of pome fruit (apple/pear). Facing the climatological conditions before picking the residue loading on the fruit surface can differ enormously. Also wet (pre)grading is considered to decrease the product residue resulting to fruits which are less protected before entering the cold storage room. In this context a partially replacement of the preharvest treatments by one postharvest application could offer a reliable alternative to the PPP reduction program (Plant Protection Products) in the orchard. A standardized application method by dipping or drenching will cover the fruits homogenically resulting in a rationalized fungicide use compared to the preharvest sprayings in the orchard. For the Belgium market Philabuster (imazalil & pyrimethanil) is registered for postharvest treatments since for this product a proper solution for the waste water of postharvest uses was developed to protect surface waters (Funds technology). Philabuster provides an advanced mould control towards fruit rot pathogens Gloeosporium spp., Botrytis cinerea and Penicillium spp. In this context several trials were set up to evaluate the biological efficacy of Philabuster alone or in combination with preharvest sprayings in the orchard. In concrete different preharvest spraying schedules were applied in the last six weeks before harvest on apple and pear facing parameters as rational fungicide use, antifungal effectiveness and cost price. The purpose was to select the optimal combination in

  10. Pathogenicity of and plant immunity to soft rot pectobacteria

    Directory of Open Access Journals (Sweden)

    Pär Roland Davidsson

    2013-06-01

    Full Text Available Soft rot Pectobacteria are broad host range enterobacterial pathogens that cause disease on a variety of plant species including the major crop potato. Pectobacteria are aggressive necrotrophs that harbor a large arsenal of plant cell wall degrading enzymes as their primary virulence determinants. These enzymes together with additional virulence factors are employed to macerate the host tissue and promote host cell death to provide nutrients for the pathogens. In contrast to (hemibiotrophs such as Pseudomonas, type three secretion systems (T3SS and T3 effectors do not appear central to pathogenesis of Pectobacteria. Indeed, recent genomic analysis of several Pectobacterium species including the emerging pathogen Pectobacterium wasabiae has shown that many strains lack the entire T3SS as well as the T3 effectors. Instead, this analysis has indicated the presence of novel virulence determinants. Resistance to broad host range Pectobacteria is complex and does not appear to involve single resistance genes. Instead, activation of plant innate immunity systems including both SA and JA/ET mediated defenses appears to play a central role in attenuation of Pectobacterium virulence. These defenses are triggered by detection of pathogen-associated molecular patterns (PAMPs or recognition of modified-self such as damage-associated molecular patterns (DAMPs and result in enhancement of basal immunity (Pattern-triggered immunity, PTI. In particular plant cell-wall fragments released by the action of the degradative enzymes secreted by Pectobacteria are major players in enhanced immunity towards these pathogens. Most notably bacterial pectin degrading enzymes release oligogalacturonide (OG fragments recognized as DAMPs activating innate immune responses. Recent progress in understanding OG recognition and signaling allows novel genetic screens for OG-insensitive mutants and will provide new insights into plant defense strategies against necrotrophs such as

  11. 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.

  12. 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.

  13. A new Approach for Quantifying Root-Reinforcement of Streambanks: the RipRoot Model

    Science.gov (United States)

    Pollen, N. L.; Simon, A.

    2003-12-01

    Riparian vegetation plays an important role in controlling geotechnical and fluvial processes acting along and within streambanks through the binding effects of roots. Quantification of this mechanical effect is therefore essential to accurately model streambank stability. Until now, most attempts to include the effects of root reinforcement by riparian vegetation have used root-cohesion values estimated using the Wu et al. (1979) equation, requiring the tensile strengths and diameters of the roots crossing the potential shear-plane. However, the Wu et al. equation is a static model that assumes that all roots break, and that they all break simultaneously. Field observations and laboratory experiments have shown that in reality the roots do not all break simultaneously, and that the breaking of roots during mass failure is in fact a dynamic process. Static models such as the Wu et al. equation are therefore likely to produce overestimations of cohesion due to roots. As a response to this concern, a dynamic root reinforcement model (RipRoot) was developed, based on the concepts of fiber bundle models (FBM's) used in materials science. Within the model the root-soil system is loaded incrementally resulting in progressive root breaking and redistribution of stresses from the broken roots to the remaining intact roots in the soil matrix. The redistribution and loading process continues until either all of the roots have broken, or equilibrium is reached where the root network supports the driving force imposed on the bank. The increase in bank cohesion using the static Wu et al. equation are 18% to 38% higher than RipRoot for riparian tree species, including Black Willow, Sandbar Willow, Cottonwood, River Birch and Eastern Sycamore, and 49% higher for Switch Grass. These variations in cohesion values can have a significant impact on streambank Factor of Safety (Fs) values calculated using the Simon et al. (2000) bank-stability model. For example, a 3m high silt

  14. Evidence from Serpula lacrymans that 2,5-dimethoxyhydroquinone Is a lignocellulolytic agent of divergent brown rot basidiomycetes.

    Science.gov (United States)

    Korripally, Premsagar; Timokhin, Vitaliy I; Houtman, Carl J; Mozuch, Michael D; Hammel, Kenneth E

    2013-04-01

    Basidiomycetes that cause brown rot of wood are essential biomass recyclers in coniferous forest ecosystems and a major cause of failure in wooden structures. Recent work indicates that distinct lineages of brown rot fungi have arisen independently from ligninolytic white rot ancestors via loss of lignocellulolytic enzymes. Brown rot thus proceeds without significant lignin removal, apparently beginning instead with oxidative attack on wood polymers by Fenton reagent produced when fungal hydroquinones or catechols reduce Fe(3+) in colonized wood. Since there is little evidence that white rot fungi produce these metabolites, one question is the extent to which independent lineages of brown rot fungi may have evolved different Fe(3+) reductants. Recently, the catechol variegatic acid was proposed to drive Fenton chemistry in Serpula lacrymans, a brown rot member of the Boletales (D. C. Eastwood et al., Science 333:762-765, 2011). We found no variegatic acid in wood undergoing decay by S. lacrymans. We found also that variegatic acid failed to reduce in vitro the Fe(3+) oxalate chelates that predominate in brown-rotting wood and that it did not drive Fenton chemistry in vitro under physiological conditions. Instead, the decaying wood contained physiologically significant levels of 2,5-dimethoxyhydroquinone, a reductant with a demonstrated biodegradative role when wood is attacked by certain brown rot fungi in two other divergent lineages, the Gloeophyllales and Polyporales. Our results suggest that the pathway for 2,5-dimethoxyhydroquinone biosynthesis may have been present in ancestral white rot basidiomycetes but do not rule out the possibility that it appeared multiple times via convergent evolution. PMID:23377930

  15. 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.

  16. Evaluation of some garlic (Allium Sativum L.) mutants resistant to white rot disease by RAPD analysis

    International Nuclear Information System (INIS)

    Random amplified polymorphic DNA (RAPD) analysis was used to evaluate genetic diversity among eight garlic mutants resistant to white rot disease (Sclerotium cepivorum) and two controls. Twelve of 13 synthetic random primers were found to identify polymorphism in amplification products. Mutants characterised with moderate resistance to white rot were closely related to the control using cluster and correlation analyses. On the other hand, highly resistant mutants were quite distant from the control with low correlation coefficients. The banding patterns produced by primer OPB-15 (GGAAGGGTGTT) with highly resistant mutants may be used as genetic markers for early selection of resistant plants. (author)

  17. Analysis of Fusarium avenaceum Metabolites Produced during Wet Apple Core Rot

    DEFF Research Database (Denmark)

    Sørensen, Jens Laurids; Phipps, Richard Kerry; Nielsen, Kristian Fog;

    2009-01-01

    Wet apple core rot (wACR) is a well-known disease of susceptible apple cultivars such as Gloster, Jona Gold, and Fuji. Investigations in apple orchards in Slovenia identified Fusarium avenaceum, a known producer of several mycotoxins, as the predominant causal agent of this disease. A LC-MS/MS me......Wet apple core rot (wACR) is a well-known disease of susceptible apple cultivars such as Gloster, Jona Gold, and Fuji. Investigations in apple orchards in Slovenia identified Fusarium avenaceum, a known producer of several mycotoxins, as the predominant causal agent of this disease. A LC...

  18. Characterisation of Alternaria species-groups associated with core rot of apples in South Africa

    DEFF Research Database (Denmark)

    Serdani, M.; Kang, J.C.; Andersen, Birgitte;

    2002-01-01

    Alternaria core rot of red apple cultivars is a serious post-harvest disease in South Africa. Thirty isolates of Alternaria spp. previously isolated from apple, together with reference isolates of A. alternata and A. infectoria, were characterised and grouped according to their sporulation patterns...... the other species-groups, as all isolates had a distinction of 35 base pair insertions and 6 base pair deletions in the ITS regions. The results obtained in the present study showed that the major pathogens associated with core rot disease of Top Red apples in South Africa belong to the A. tenuissima...

  19. Radionic nonuniform black strings

    Science.gov (United States)

    Tamaki, Takashi; Kanno, Sugumi; Soda, Jiro

    2004-01-01

    Nonuniform black strings in the two-brane system are investigated using the effective action approach. It is shown that the radion acts as a nontrivial hair of the black strings. From the brane point of view, the black string appears as the deformed dilatonic black hole which becomes a dilatonic black hole in the single brane limit and reduces to the Reissner-Nordström black hole in the close limit of two-branes. The stability of solutions is demonstrated using catastrophe theory. From the bulk point of view, the black strings are proved to be nonuniform. Nevertheless, the zeroth law of black hole thermodynamics still holds.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Environmental Impact of Using Phlebiopsis gigantea in Stump Treatment Against Heterobasidion annosum sensu lato and Screening Root Endophytes to Identify Other Novel Control Agents

    OpenAIRE

    Terhonen, Eeva-Liisa

    2015-01-01

    Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) cover large areas in boreal regions with significant economic importance to Finnish forest industry. Approximately 15% of the spruce trees felled in Finland are rotten and thus commercially less valuable. The majority of this conifer wood decay is due to the root and butt rot pathogen Heterobasidion annosum sensu lato. Extensive logging of conifer forests has changed the environment into favouring this pathogen in stands where it o...

  2. Evaluating paradox walnut rootstocks for resistance to Armillaria root disease

    Science.gov (United States)

    The most common Juglans regia (English walnut) rootstock in California is Paradox, a hybrid between J. hindsii (Northern California black walnut) and J. regia. Unfortuntely, Paradox rootstock is highly susceptible to Armillaria root disease. The relative resistance of new clonal, Paradox rootstock...

  3. Grass Roots: African Origins of an American Art

    OpenAIRE

    E. N. Anderson

    2010-01-01

    Review of Grass Roots: African Origins of an American Art. Dale Rosengarten, Theodore Rosengarten, and Enid Schildkrout, eds. 2008. Museum for African Art, New York. Distributed by University of Washington Press, Seattle. Pp. 269, copiously illustrated in black-and-white and color. ISBN (cloth) 978-0-945802-50-1, (paper) 978-0-945802-51-8.

  4. Black Urine

    Directory of Open Access Journals (Sweden)

    Rahim Vakili

    2016-06-01

    Full Text Available A 2-year-old boy was born at term of healthy, non-consanguineous Iranian parents. His mother attended in the clinic with the history of sometimes discoloration of diapers after passing urine. She noticed that first at the age of one month with intensified in recent months. His Physical examination and growth parameters were normal. His mother denied taking any medication (sorbitol, nitrofurantoin, metronidazole, methocarbamol, sena and methyldopa (5. Qualitative urine examination showed dark black discoloration. By this history, alkaptonuria was the most clinical suspicious. A 24-hour-urine sample was collected and sent for quantitative measurements. The urine sample was highly positive for homogentisic acid and negative for porphyrin metabolites.

  5. Genetic association among root morphology, root quality and root yield in ashwagandha (Withania somnifera)

    OpenAIRE

    Kumar Ramesh R.; Reddy Anjaneya Prasanna L.; Subbaiah Chinna J.; Kumar Niranjana A.; Prasad Nagendra H.N.; Bhukya Balakishan

    2011-01-01

    Ashwagandha (Withania somnifera) is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes) and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant) and crude fiber content exhibited strong association among them and ...

  6. 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.

  7. Root canal irrigants

    Directory of Open Access Journals (Sweden)

    Kandaswamy Deivanayagam

    2010-01-01

    Full Text Available 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.

  8. Interaction between N-fertilizer and water availability on borer-rot complex in sugarcane

    Directory of Open Access Journals (Sweden)

    Luiz Eduardo da Rocha Pannuti

    2015-03-01

    Full Text Available This study aimed to evaluate the effects of nitrogen availability in fertigation and rainfed management, as well as their interactions with the incidence of and damage caused by D. saccharalis and red rot in sugarcane. The experiment consisted of four treatments (0 and 150 kg ha–1 of N-fertilizer with irrigation; 0 and 150 kg ha–1 of N-fertilizer in rainfed management in a randomized complete block design with four replications. The evaluated parameters were the number of holes and internodes with red rot per meter of cultivation, stalk yield and sugar content. In the laboratory (T = 25 ± 2 °C; R.H. = 70 ± 10%: 12:12-L:D, we evaluated the attractiveness and consumption of fragments of stalks from the different treatments for fourth instar larvae through choice and no-choice tests in a randomized complete block design with ten replications. Nitrogen fertilization via irrigation has favorable effects on borer-rot complex and leads to higher gains in stalk and sugar yields when compared to rainfed management. The increments of stalk and sugar yields due to nitrogen fertilization compensates for the increase in borer-rot complex infestation. In laboratory tests, D. saccharalis larvae were similarly attracted to all treatments regardless of the doses of N-fertilizer or the water regimes evaluated. However, fragments of sugarcane stalks produced with nitrogen fertilization were consumed more by D. saccharalis in both water regimes.

  9. Draft Genome Sequence of the White-Rot Fungus Obba rivulosa 3A-2.

    Science.gov (United States)

    Miettinen, Otto; Riley, Robert; Barry, Kerrie; Cullen, Dan; de Vries, Ronald P; Hainaut, Matthieu; Hatakka, Annele; Henrissat, Bernard; Hildén, Kristiina; Kuo, Rita; LaButti, Kurt; Lipzen, Anna; Mäkelä, Miia R; Sandor, Laura; Spatafora, Joseph W; Grigoriev, Igor V; Hibbett, David S

    2016-01-01

    We report here the first genome sequence of the white-rot fungus Obba rivulosa (Polyporales, Basidiomycota), a polypore known for its lignin-decomposing ability. The genome is based on the homokaryon 3A-2 originating in Finland. The genome is typical in size and carbohydrate active enzyme (CAZy) content for wood-decomposing basidiomycetes. PMID:27634999

  10. 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.

  11. 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...

  12. Resident bacteria of plums and their potential for controlling brown rot after harvest

    Science.gov (United States)

    Fruit microflora has been the richest source of antagonists against fruit decays and the active ingredient in all currently available commercial biocontrol products. A comprehensive evaluation of plum bacteria for biocontrol activity against Monilinia fructicola, causing brown rot of stone fruit, w...

  13. 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. PMID:24502208

  14. Short read sequencing for Genomic Analysis of the brown rot fungus Fibroporia radiculosa

    Science.gov (United States)

    The practical capability of short read sequencing for whole genome gene prediction was investigated for Fibroporia radiculosa, a copper-tolerant basidiomycete fungus that causes brown rot decay of wood. Illumina GAIIX reads from a single run of a paired-end library (75 nt read length, 300 bp insert...

  15. Control of brown rot of stone fruits by brief heated water immersion treatments

    Science.gov (United States)

    The effectiveness of brief (30 or 60 s) immersion in water at 24, 50, 55, 60, 65, or 70 ºC was evaluated for the control of brown rot, caused by Monilinia fructicola, on California-grown peaches, nectarines, and plums. Inoculated fruits were treated and either stored at 20 ºC for 5 days or at 0 ºC f...

  16. Culturable bacteria from plum fruit surfaces and their potential for controlling brown rot after harvest

    Science.gov (United States)

    Fruit microflora has been the richest source of antagonists against fruit decays and the active ingredient in all currently available commercial biocontrol products. A comprehensive evaluation of plum bacteria for biocontrol activity against Monilinia fructicola, causing brown rot of stone fruit, w...

  17. Organics and mineral fertilizers and biological control on the incidence of stalk rot and corn yield

    Directory of Open Access Journals (Sweden)

    Elena Blume

    2014-06-01

    Full Text Available The expansion of area under maize (Zea mays L. and the use of no tillage have favored the incidence of stalk rot on this crop. The study aimed to evaluate the organic fertilizers and the treatment of corn seeds with Trichoderma spp. on the production of dry matter (DM of shoot, incidence of stalk rot and corn yield. The experiment consisted in a factorial with split-plot in strips, on the randomized block design with four replicates, and the fertilization treatments (pig slurry; swine deep bedding; cattle slurry; mineral fertilizer; control treatment were applied to the plots and the seeds treatment (with and without Trichoderma spp. in the subplots. At the flowering stage, three corn plants per subplot were collected for the assessment of DM production. At physiological maturity stage, the incidence of stalk rot was assessed, and the ears of corn harvested for productivity assessment. The organic and mineral fertilizers increased the production of DM and productivity of corn. Trichoderma spp. increased the production of DM of corn, but had no reflection on productivity. The incidence of stalk rot in corn was higher in treatments with organic and mineral fertilization. Organic fertilizers increase dry matter production of shoot and corn yield, and Trichoderma spp. provides an increase in dry matter production of shoot.

  18. 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

  19. 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.

  20. Draft Genome Sequence of a Virulent Pectobacterium carotovorum subsp. brasiliense Isolate Causing Soft Rot of Cucumber

    OpenAIRE

    Onkendi, Edward M.; Ramesh, Aadi Moolam; Kwenda, Stanford; Naidoo, Sanushka; Moleleki, Lucy

    2016-01-01

    Pectobacterium carotovorum subsp. brasiliense causes soft rot and blackleg diseases on potatoes, ornamentals, and other crops of economic importance. Here, we report a draft genome sequence of a highly virulent P. carotovorum subsp. brasiliense strain, PcbHPI01, isolated from a cucumber in South Africa.

  1. Draft Genome Sequence of the White-Rot Fungus Obba rivulosa 3A-2

    Science.gov (United States)

    Riley, Robert; Barry, Kerrie; Cullen, Dan; de Vries, Ronald P.; Hainaut, Matthieu; Hatakka, Annele; Henrissat, Bernard; Kuo, Rita; LaButti, Kurt; Lipzen, Anna; Mäkelä, Miia R.; Sandor, Laura; Spatafora, Joseph W.; Grigoriev, Igor V.; Hibbett, David S.

    2016-01-01

    We report here the first genome sequence of the white-rot fungus Obba rivulosa (Polyporales, Basidiomycota), a polypore known for its lignin-decomposing ability. The genome is based on the homokaryon 3A-2 originating in Finland. The genome is typical in size and carbohydrate active enzyme (CAZy) content for wood-decomposing basidiomycetes. PMID:27634999

  2. Resistance in watermelon rootstocks to crown rot caused by Phytophthora capsici

    Science.gov (United States)

    Phytophthora crown and fruit rot caused by Phytophthora capsici is becoming an important and emerging disease of watermelon (Citrullus lanatus) in south eastern United States. In recent years, the practice of grafting seedless watermelons (triploids) onto rootstocks belonging to other Cucurbitaceae...

  3. Effect of phytophthora capsici crown rot on watermelon rootstocks and grafts

    Science.gov (United States)

    Crown and fruit rot caused by Phytophthora capsici is becoming an important and emerging disease of watermelon in the southeastern United States. In recent years, the practice of grafting seedless watermelons onto rootstocks belonging to other Cucurbitaceae genera is also gaining acceptance in our l...

  4. Characterization of Resistance Gene Analog Polymorphisms in sugarcane cultivars with varying levels of red rot resistance

    Directory of Open Access Journals (Sweden)

    J. Jayashree, A. Selvi and N.V. Nair

    2010-07-01

    Full Text Available Resistance Gene Analog (RGA strategy is being exploited perfectly for the identification, tagging and mapping of majorgenes or Quantitative Trait Loci for disease resistance. About 29 RGA primers designed from the conserved domains ofresistance proteins, were used to analyse the genetic diversity among the 40 sugarcane cultivars that vary in their resistanceto red rot disease. The genetic similarity values ranged from 58.4 - 90% with the mean genetic similarity of 74.2%. Clusteranalysis resulted in a dendrogram with 3 major clusters and a clear distinction of resistant and susceptible varieties wasobserved. A total of 25 specific fragments amplified by 14 primers were identified to be associated with resistance and 8specific fragments amplified by 8 primers were associated with susceptibility. The primers RGA – 137, RGA 396, RGA-231 and RGA-118 amplified maximum number of resistant or susceptible specific fragments (3. Amplification of the red rotresistant variety Bo 91 and the red rot susceptible variety CoC 671 with the twenty nine RGA primers, followed bysequencing and homology analysis revealed significant homologies with the RGA’s of rice, maize and sugarcane. TheseRGA’s that were found to be associated with red rot resistant/ susceptible varieties are a valuable source of markers that canbe tested for screening red rot resistance in breeding programs

  5. 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.

  6. Ft. Collins sugar beet germplasm evaluated for rhizomania and storage rot resistance in Idaho, 2015

    Science.gov (United States)

    Fifty-seven sugar beet (Beta vulgaris L.) lines from the USDA-ARS Ft. Collins sugar beet program and four check cultivars were screened for resistance to Beet necrotic yellow vein virus (BNYVV), the causal agent of rhizomania, and storage rot. The rhizomania evaluation was conducted at the USDA-ARS...

  7. 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

  8. 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...

  9. Description of Pseudacrobeles (Bunobus) arboricola sp. n. (Rhabditida: Cephalobidae) from rotting wood in Roztochya, Ukraine

    NARCIS (Netherlands)

    Holovachov, O.V.; Boström, S.

    2006-01-01

    Pseudacrobeles (Bunobus) arboricola sp. n., a new species of free-living nematodes from rotting wood in Ukraineis described. It is characterised by the absence of labial and cephalic probolae, presence of bar-shaped cheilorhabdia, low corpus-isthmus ratio (1.5-2.3), excretory pore anterior to corpus

  10. 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

  11. 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.

  12. 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.

  13. In-fiber silicon microsphere as a hybrid Fabry-Pérot microcavity for temperature sensing

    OpenAIRE

    Xiao, L.M.; Healy, N; Hawkins, T.; Jones, M; Ballato, J.; Gibson, U.; Peacock, A. C.

    2015-01-01

    A silicon microsphere was fabricated inside a fiber forming a hybrid Fabry-Pérot microcavity. The large difference in indices and thermal-optic coefficients of the sphere and its silica cladding are exploited for high-sensitivity temperature sensing.

  14. 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.

  15. Aplikace Balanced Scorecard ve společnosti BATR šrot, a. s.

    OpenAIRE

    Bartoš, Vít

    2014-01-01

    This Master's thesis applies Balanced Scorecard in BATR šrot, a.s. It consists of theoretical part and practical part. Theoretical part defines Balanced Scorecard components, tools of strategic analysis and INFA Performance Indicator Diagnostic System. Practical part applies the aforementioned tools. The outcome of this Master's thesis is a strategy map and evaluation of the company performance.

  16. 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,

  17. 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.

  18. Black hole evaporation in an expanding universe

    International Nuclear Information System (INIS)

    We calculate the quantum radiation power of black holes which are asymptotic to the Einstein-de Sitter universe at spatial and null infinities. We consider two limiting mass accretion scenarios, no accretion and significant accretion. We find that the radiation power strongly depends on not only the asymptotic condition but also the mass accretion scenario. For the no accretion case, we consider the Einstein-Straus solution, where a black hole of constant mass resides in the dust Friedmann universe. We find negative cosmological correction besides the expected redshift factor. This is given in terms of the cubic root of ratio in size of the black hole to the cosmological horizon, so that it is currently of order 10-5(M/106Mo-dot)1/3(t/14Gyr)-1/3 but could have been significant at the formation epoch of primordial black holes. Due to the cosmological effects, this black hole has not settled down to an equilibrium state. This cosmological correction may be interpreted in an analogy with the radiation from a moving mirror in a flat spacetime. For the significant accretion case, we consider the Sultana-Dyer solution, where a black hole tends to increase its mass in proportion to the cosmological scale factor. In this model, we find that the radiation power is apparently the same as the Hawking radiation from the Schwarzschild black hole of which mass is that of the growing mass at each moment. Hence, the energy loss rate decreases and tends to vanish as time proceeds. Consequently, the energy loss due to evaporation is insignificant compared to huge mass accretion onto the black hole. Based on this model, we propose a definition of quasi-equilibrium temperature for general conformal stationary black holes

  19. Black Silicon Solar Cells with Black Ribbons

    DEFF Research Database (Denmark)

    Davidsen, Rasmus Schmidt; Tang, Peter Torben; Mizushima, Io;

    2016-01-01

    We present the combination of mask-less reactive ion etch (RIE) texturing and blackened interconnecting ribbons as a method for obtaining all-black solar panels, while using conventional, front-contacted solar cells. Black silicon made by mask-less reactive ion etching has total, average...... in the range 15.7-16.3%. The KOH-textured reference cell had an efficiency of 17.9%. The combination of black Si and black interconnecting ribbons may result in aesthetic, all-black panels based on conventional, front-contacted silicon solar cells....... reflectance below 0.5% across a 156x156 mm2 silicon (Si) wafer. Black interconnecting ribbons were realized by oxidizing copper resulting in reflectance below 3% in the visible wavelength range. Screen-printed Si solar cells were realized on 156x156 mm2 black Si substrates with resulting efficiencies...

  20. Noncommutative black holes

    International Nuclear Information System (INIS)

    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole

  1. Black Entrepreneurship in America.

    Science.gov (United States)

    Green, Shelley; Pryde, Paul

    The economic condition of black Americans is discussed, proceeding from the assumption that black economic progress does not depend on a renewed struggle for unobtained civil rights, but rather on the creative response of black Americans to economic opportunity and problems. In the long run, black economic development must rely on the…

  2. 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.

  3. Diversity of symbiotic root endophytes of the Helotiales in ericaceous plants and the grass, Deschampsia flexuosa

    OpenAIRE

    Zijlstra, J.D.; Hof, van 't, G.; Baar, J.; Verkley, G.J.M.; Summerbell, R.C; Paradi, I.; Braakhekke, W.G.; Berendse, F.

    2005-01-01

    In a study of fungi growing in various root-associated habitats in and around Picea mariana, black spruce, in northern Ontario, Canada, an examination was made of the degree to which differences in growth sites within an area of a few square kilometers might influence the structure of root-associated filamentous microfungal populations. Picea mariana roots were collected at four strongly differing boreal forest sites: an undisturbed forest site with deep litter and humus layers; a recently re...

  4. Roots and routes

    DEFF Research Database (Denmark)

    Christensen, Ann-Dorte; Jensen, Sune Qvotrup

    2011-01-01

    arguing that there is a dynamic interplay between roots and routes in people's lives. The empirical point of departure is narratives about roots and routes by ethnic minorities settled in Aalborg East, an underprivileged neighbourhood in northern Denmark. One of the main findings is a gap between the...... somewhat paradoxical finding is that it appears to be more difficult for transnational migrants to maintain their roots in the country of origin when they go back than it was to establish new roots in the host country...

  5. Roots of Dehn twists

    OpenAIRE

    McCullough, Darryl; Rajeevsarathy, Kashyap

    2009-01-01

    D. Margalit and S. Schleimer found examples of roots of the Dehn twist about a nonseparating curve in a closed orientable surface, that is, homeomorphisms whose nth power is isotopic to the Dehn twist. Our main theorem gives elementary number-theoretic conditions that describe the values of n for which an nth root exists, given the genus of the surface. Among its applications, we show that n must be odd, that the Margalit-Schleimer roots achieve the maximum value of n among the roots for a gi...

  6. 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 ...

  7. Fusarium species associated with fruit rot of banana (Musa spp.), papaya (Carica papaya) and guava (Psidium guajava)

    OpenAIRE

    Zakaria, L.; Mazzura, W. C.; Kong, W. H.; S. Baharuddin

    2012-01-01

    A total of 60 isolates of Fusarium were isolated from fruit rot of banana (Musa spp.), papaya (Carica papaya) and guava(Psidium guajava). The most common species recovered from the fruit rot of the three fruit crops were F. semitectum(40 %), F. solani (38.3 %), F. verticillioides (11.7 %) and F. oxysporum (10 %). Fusarium semitectum was isolated from fruit rot of banana, papaya and guava; F. oxysporum from banana and papaya; F. solani from banana and guava and F.verticillioides from banana. F...

  8. 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].

  9. 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.

  10. 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. PMID:27050573

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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.

  16. The genome of black raspberry (Rubus occidentalis).

    Science.gov (United States)

    VanBuren, Robert; Bryant, Doug; Bushakra, Jill M; Vining, Kelly J; Edger, Patrick P; Rowley, Erik R; Priest, Henry D; Michael, Todd P; Lyons, Eric; Filichkin, Sergei A; Dossett, Michael; Finn, Chad E; Bassil, Nahla V; Mockler, Todd C

    2016-09-01

    Black raspberry (Rubus occidentalis) is an important specialty fruit crop in the US Pacific Northwest that can hybridize with the globally commercialized red raspberry (R. idaeus). Here we report a 243 Mb draft genome of black raspberry that will serve as a useful reference for the Rosaceae and Rubus fruit crops (raspberry, blackberry, and their hybrids). The black raspberry genome is largely collinear to the diploid woodland strawberry (Fragaria vesca) with a conserved karyotype and few notable structural rearrangements. Centromeric satellite repeats are widely dispersed across the black raspberry genome, in contrast to the tight association with the centromere observed in most plants. Among the 28 005 predicted protein-coding genes, we identified 290 very recent small-scale gene duplicates enriched for sugar metabolism, fruit development, and anthocyanin related genes which may be related to key agronomic traits during black raspberry domestication. This contrasts patterns of recent duplications in the wild woodland strawberry F. vesca, which show no patterns of enrichment, suggesting gene duplications contributed to domestication traits. Expression profiles from a fruit ripening series and roots exposed to Verticillium dahliae shed insight into fruit development and disease response, respectively. The resources presented here will expedite the development of improved black and red raspberry, blackberry and other Rubus cultivars. PMID:27228578

  17. The genome of black raspberry (Rubus occidentalis).

    Science.gov (United States)

    VanBuren, Robert; Bryant, Doug; Bushakra, Jill M; Vining, Kelly J; Edger, Patrick P; Rowley, Erik R; Priest, Henry D; Michael, Todd P; Lyons, Eric; Filichkin, Sergei A; Dossett, Michael; Finn, Chad E; Bassil, Nahla V; Mockler, Todd C

    2016-09-01

    Black raspberry (Rubus occidentalis) is an important specialty fruit crop in the US Pacific Northwest that can hybridize with the globally commercialized red raspberry (R. idaeus). Here we report a 243 Mb draft genome of black raspberry that will serve as a useful reference for the Rosaceae and Rubus fruit crops (raspberry, blackberry, and their hybrids). The black raspberry genome is largely collinear to the diploid woodland strawberry (Fragaria vesca) with a conserved karyotype and few notable structural rearrangements. Centromeric satellite repeats are widely dispersed across the black raspberry genome, in contrast to the tight association with the centromere observed in most plants. Among the 28 005 predicted protein-coding genes, we identified 290 very recent small-scale gene duplicates enriched for sugar metabolism, fruit development, and anthocyanin related genes which may be related to key agronomic traits during black raspberry domestication. This contrasts patterns of recent duplications in the wild woodland strawberry F. vesca, which show no patterns of enrichment, suggesting gene duplications contributed to domestication traits. Expression profiles from a fruit ripening series and roots exposed to Verticillium dahliae shed insight into fruit development and disease response, respectively. The resources presented here will expedite the development of improved black and red raspberry, blackberry and other Rubus cultivars.

  18. Black Travesty

    Directory of Open Access Journals (Sweden)

    Angela Khristin Brown

    2013-01-01

    Full Text Available Quincy Troupe is a visionary poet who is always reaching out to walk and dance words upon a single page. Quincy uses his imagination through dialog with certain looks of rhythm of words which bounce off the page of unforgotton sound. Quincy prances accross word that burst from childhood dreams that make you smile. Perhaps there is an explanation to why he creates hope to the deturbed voices in our head. It is through language that he decodes similes, metaphores and apostrophes out of clarity that trace our roots to our dark past which is from the eye of the beholder. Quincy's words bounce back at us with words of wisdom from the voice that humms in our head. Quincy maps his experience into beautiful shcemes of imprisoned thought. Quincy has mirrored a managerie of space on a blank page using pain and agony to slowly develop an illusion for movement. Quincy's sentex is the blues in space that echoes in the air in spoken tongues. It is from dreams we pulsate life through shared idioms of time. When we can identify in how sorrow has touched our lives, we believe in fear itself will keep us alive. Fear is an invisible ploom we live through rituals from desire. It is from this madness we imagine love is far deeper than fear itself. 

  19. Trends of development of soybean root rot%大豆根腐病发育动态

    Institute of Scientific and Technical Information of China (English)

    白雪梅

    2003-01-01

    @@ 加强不同农作物专业化和集中化种植,全面要求科学依据的轮作结构和大豆轮作饱和度,推广到生产上可获得稳定的产量和经济效益,并达到植物卫生部门的认可.

  20. Biocontrol of Fusarium Crown and Root Rot and Promotion of Growth of Tomato by Paenibacillus Strains Isolated from Soil

    OpenAIRE

    Xu, Sheng Jun; Kim, Byung Sup

    2014-01-01

    In this study, bacterial strains were isolated from soils from 30 locations of Samcheok, Gangwon province. Of the isolated strains, seven showed potential plant growth promoting and antagonistic activities. Based on cultural and morphological characterization, and 16S rRNA gene sequencing, these strains were identified as Paenibacillus species. All seven strains produced ammonia, cellulase, hydrocyanic acid, indole-3-acetic acid, protease, phosphatase, and siderophores. They also inhibited th...

  1. Black holes thermodynamics, information, and firewalls

    CERN Document Server

    Mann, Robert B

    2015-01-01

    This book reflects the resurgence of interest in the quantum properties of black holes, culminating most recently in controversial discussions about firewalls. On the thermodynamic side, it describes how new developments allowed the inclusion of pressure/volume terms in the first law, leading to a new understanding of black holes as chemical systems, experiencing novel phenomena such as triple points and reentrant phase transitions. On the quantum-information side, the reader learns how basic arguments undergirding quantum complementarity have been shown to be flawed; and how this suggests that a black hole may surround itself with a firewall: a violent and chaotic region of highly excited states. In this thorough and pedagogical treatment, Robert Mann traces these new developments from their roots to our present-day understanding, highlighting their relationships and the challenges they present for quantum gravity.

  2. 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 is...

  3. 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...

  4. BIODEGRADATION OF ENVIRONMENTAL POLLUTANTS BY THE WHITE ROT FUNGUS PHANEROCHATETE CHRYSOSPORIUM: INVOLVEMENT OF THE LIGNIN DEGRADING SYSTEM

    Science.gov (United States)

    The white-rot fungus Phanerochaete chrysosporium has the ability to degrade's wide variety of structurally diverse organic compounds, including a number of environmentall3 persistent organopollutants. he unique biodegradative abilities of this fungus appears to be dependent upon ...

  5. Study on the Occurrence and Epidemic Model of Rape Sclerotinia Stem Rot of ‘Zheyou 50’

    Directory of Open Access Journals (Sweden)

    Xu Sen-fu

    2013-03-01

    Full Text Available In order to investigate invading and epidemic rules of rape sclerotinia stem rot of ‘Zheyou 50’ and promote the development of brassica campestris industry, this paper studied the outbreak regularity and epidemic model of rape sclerotinia stem rot according to field investigation and infection. The result showed that machinery direct seeding rape was good for the occurrence of sclerotinia stem rot for the reason of late seeding and high density. The period from water damage appeared to wilting death was about 15 days only, when latent period from nature mycelium to invade to total was about 8-17 days with a infected rate up to 13.2%. The epidemic dynamic showed to be linear-rise trend. Flowering stage was the main epidemic period of disease. Diffusion of rape sclerotinia stem rot fitted a logistic function model.

  6. Biodegradation of 1,2,3,4-tetrachlorodibenzo-p-dioxin in liquid broth by brown-rot fungi.

    Science.gov (United States)

    Perlatti, Bruno; da Silva, Maria Fátima das Graças Fernandes; Fernandes, João Batista; Forim, Moacir Rossi

    2013-11-01

    Dioxins are a class of extremely hazardous molecules that might pose a threat to the environment. This work evaluated the microbial degradation of 1,2,3,4-tetrachlorodibenzo-p-dioxin (1,2,3,4-TCDD), in liquid broth using three brown-rot fungi and one white-rot fungi as control. A fast and reliable extraction method with recoveries of over 98% together with a validated GC-MS method was developed, and applied to quantify 1,2,3,4-TCDD in liquid broth, mycelia and reaction flask, with detection limits of 10 ppb. Among the four strains tested, brown-rot fungus Aspergillus aculeatus showed best results, removing up to 21% of dioxin after 30-day incubation. The results open both a path for biotechnological interest in bioremediation purposes and environmental behavior studies by using brown-rot fungus.

  7. 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...

  8. ESTROGEN RECEPTORS OF HAIRS BLACKS AND WHITES

    Directory of Open Access Journals (Sweden)

    H. Laswati

    2014-12-01

    Full Text Available Background: Aging is termed as same as degenerative process, in which all part of tissue organs retarted the microstructure either macrostructure, forming and function even the colour, including black hair change to white hair. Several researchers have been recommended that estrogen hormone be able ease black to white hair, but hormone without any presenting of receptor won’t be work properly. The main aim of this study were to determine amount of estrogen receptor contents in famales and males black and white hairs included the microscopically structure. Method: Twelve females and males there were 50 -56 years old each pairs black and white head hairs were plucked along with follicles. This estrogen receptors analyzed using radioreceptor binding assay there were 5mm eah hair follices including the root cutted and each pair put its in 2 ml glass tube already filled in with 500 µl 125I-estradiol and incubated in 37oC for 3 hrs. Following times were over the tube flushed twice carefully the hair won’t be flushed. Then count by putting in the gamma counter chamber for 1 minute each. The values that shown in the monitor as CPM (count per minute, recorded as receptor of estradiol. Results: Mean (±SD sum estrogen receptor in females black and white hairs were 479.3 ± 37.5 and 387.7 ± 33.0, but significantly decreased in male black hair was 316.9±17.8 and 274.0 ± 19.8. All those pairs significantly different either female black and white hairs or male black and white hair and also significantly different among groups. Conclusion: The lowest estrogen receptors recorded in male white hairs and microstructure decreasing of melanin contents.

  9. Study on the effect of rhamnoIipid-enhanced white rot fungi on the treatment of puIping bIack Iiquor%鼠李糖脂强化白腐菌处理制浆黑液效果研究

    Institute of Scientific and Technical Information of China (English)

    张祥胜; 邹学东; 顾光辉

    2016-01-01

    The enhancement effects of different additives,including tween,rhamnolipids,CuSO4,ethanol,etc. on the treatment of white-rot fungi treated black liquid have been studied. It is found that rhamnolipids can enhance reme-diation effect better. When its mass concentration is in the range of 50-60 mg/L ,the treatment effect is the best. Cul-turing after the rhamnolipid-producing Pseudomonas aeruginosa strain and white rot fungi inoculate black liquor ,the COD can be reduced by 44%. This research provides a new idea for the microbial treatment of pulping black liquid.%研究了吐温、鼠李糖脂、硫酸铜和乙醇等不同添加物对白腐菌处理黑液效果的强化作用,发现鼠李糖脂能够较好地强化修复效果,当其质量浓度在50~60 mg/L时处理效果最佳。将产生鼠李糖脂的铜绿假单胞菌与白腐菌共同接种黑液后培养,可将COD降低44%。本研究为黑液的微生物处理提供了新的思路。

  10. Visualization of the mycelia of wood-rotting fungi by fluorescence in situ hybridization using a peptide nucleic acid probe.

    Science.gov (United States)

    Nakada, Yuji; Nakaba, Satoshi; Matsunaga, Hiroshi; Funada, Ryo; Yoshida, Makoto

    2013-01-01

    White rot fungus, Phanerochaete chrysosporium, and brown rot fungus, Postia placenta, grown on agar plates, were visualized by fluorescence in situ hybridization (FISH) using a peptide nucleic acid (PNA) probe. Mycelia grown on wood chips were also clearly detected by PNA-FISH following blocking treatment. To the best of our knowledge, this is the first report on the visualization of fungi in wood by FISH. PMID:23391931

  11. Application of genomic and quantitative genetic tools to identify candidate resistance genes for brown rot resistance in peach.

    Directory of Open Access Journals (Sweden)

    Pedro J Martínez-García

    Full Text Available The availability of a complete peach genome assembly and three different peach genome sequences created by our group provide new opportunities for application of genomic data and can improve the power of the classical Quantitative Trait Loci (QTL approaches to identify candidate genes for peach disease resistance. Brown rot caused by Monilinia spp., is the most important fungal disease of stone fruits worldwide. Improved levels of peach fruit rot resistance have been identified in some cultivars and advanced selections developed in the UC Davis and USDA breeding programs. Whole genome sequencing of the Pop-DF parents lead to discovery of high-quality SNP markers for QTL genome scanning in this experimental population. Pop-DF created by crossing a brown rot moderately resistant cultivar 'Dr. Davis' and a brown rot resistant introgression line, 'F8,1-42', derived from an initial almond × peach interspecific hybrid, was evaluated for brown rot resistance in fruit of harvest maturity over three seasons. Using the SNP linkage map of Pop-DF and phenotypic data collected with inoculated fruit, a genome scan for QTL identified several SNP markers associated with brown rot resistance. Two of these QTLs were placed on linkage group 1, covering a large (physical region on chromosome 1. The genome scan for QTL and SNP effects predicted several candidate genes associated with disease resistance responses in other host-pathogen systems. Two potential candidate genes, ppa011763m and ppa026453m, may be the genes primarily responsible for M. fructicola recognition in peach, activating both PAMP-triggered immunity (PTI and effector-triggered immunity (ETI responses. Our results provide a foundation for further genetic dissection, marker assisted breeding for brown rot resistance, and development of peach cultivars resistant to brown rot.

  12. Utilization of white rot fungi for textile dye decolourisation under alkaline condition and high salt concentration in solid medium

    OpenAIRE

    Ottoni, C. A.; Santos, Cledir; Lima, Nelson

    2010-01-01

    A large amount of azo dyes are used for dyeing textiles. However, the dyes contaminate wastewaters and need to be treated. This is important because of the aesthetic, toxic and carcinogenic effects of the affected waters. Recently there has been an increase in interest in using white rot fungi (wrf) which degrade xenobiotic compounds including azo dyes. Wrf degrade lignin and others recalcitrant molecules using nonspecific extracellular enzymes. Four white rot fungi...

  13. Educational Lynching: Critical Race Theory and the Suspension of Black Boys

    Science.gov (United States)

    Payne, Macheo

    2010-01-01

    Looking at the disproportionate suspension of African American, Black male students through the lens of critical race theory, this presents arguments from a CRT how the disproportionate suspension of Black male students is rooted in white supremacy and racist policy in the United States. Local recommendations are offered for Oakland Unified School…

  14. Black Pete through the Eyes of Dutch Children

    Science.gov (United States)

    Mesman, Judi; Janssen, Sofie; van Rosmalen, Lenny

    2016-01-01

    The traditional figure of Black Pete seen during the December festivities around Sinterklaas (the Dutch Santa Claus) in the Netherlands has sparked fierce debates about his racial stereotypical characteristics and his potentially negative effects on children’s opinions about black people. The Black Pete phenomenon has even been discussed by the United Nations Committee on the Elimination of Racial Discrimination, resulting in a report urging the Netherlands to eliminate this form of racial stereotyping. The adult debate about Black Pete is clearly important, but Sinterklaas is essentially a children’s holiday. Surprisingly, there have never been any systematic studies to examine children’s views on Black Pete. The current study is the first to do so. In a sample of 201 children aged 5–7 years, we collected free descriptions of Black Pete, asked children to group him in relation to other figures, and to assign characteristics to him and comparison figures. The results showed that (1) Children are clearly aware of Black Pete’s skin color and subordinate status; (2) Children associate Black Pete more with clowns than with black people; (3) Children evaluate Black Pete very positively, but the positive characteristics do not generalize to their evaluation of black people. The findings illustrate the deep-rooted childhood origins of many Dutch people’s affection for Black Pete and their lack of awareness of his relation to racial stereotypes. This explains the resistance to changing the Black Pete figure and the slowness of the change process on this front. PMID:27322583

  15. Evaluation of stem rot in 339 Bornean tree species: implications of size, taxonomy, and soil-related variation for aboveground biomass estimates

    Science.gov (United States)

    Heineman, K. D.; Russo, S. E.; Baillie, I. C.; Mamit, J. D.; Chai, P. P.-K.; Chai, L.; Hindley, E. W.; Lau, B.-T.; Tan, S.; Ashton, P. S.

    2015-10-01

    Fungal decay of heart wood creates hollows and areas of reduced wood density within the stems of living trees known as stem rot. Although stem rot is acknowledged as a source of error in forest aboveground biomass (AGB) estimates, there are few data sets available to evaluate the controls over stem rot infection and severity in tropical forests. Using legacy and recent data from 3180 drilled, felled, and cored stems in mixed dipterocarp forests in Sarawak, Malaysian Borneo, we quantified the frequency and severity of stem rot in a total of 339 tree species, and related variation in stem rot with tree size, wood density, taxonomy, and species' soil association, as well as edaphic conditions. Predicted stem rot frequency for a 50 cm tree was 53 % of felled, 39 % of drilled, and 28 % of cored stems, demonstrating differences among methods in rot detection ability. The percent stem volume infected by rot, or stem rot severity, ranged widely among trees with stem rot infection (0.1-82.8 %) and averaged 9 % across all trees felled. Tree taxonomy explained the greatest proportion of variance in both stem rot frequency and severity among the predictors evaluated in our models. Stem rot frequency, but not severity, increased sharply with tree diameter, ranging from 13 % in trees 10-30 cm DBH to 54 % in stems ≥ 50 cm DBH across all data sets. The frequency of stem rot increased significantly in soils with low pH and cation concentrations in topsoil, and stem rot was more common in tree species associated with dystrophic sandy soils than with nutrient-rich clays. When scaled to forest stands, the maximum percent of stem biomass lost to stem rot varied significantly with soil properties, and we estimate that stem rot reduces total forest AGB estimates by up to 7 % relative to what would be predicted assuming all stems are composed strictly of intact wood. This study demonstrates not only that stem rot is likely to be a significant source of error in forest AGB estimation

  16. Interactions between cranberries and fungi: the proposed function of organic acids in virulence suppression of fruit rot fungi

    Directory of Open Access Journals (Sweden)

    Mariusz eTadych

    2015-08-01

    Full Text Available Cranberry fruit are a rich source of bioactive compounds that may function as constitutive or inducible barriers against rot-inducing fungi. The content and composition of these compounds change as the season progresses. Several necrotrophic fungi cause cranberry fruit rot disease complex. These fungi remain mostly asymptomatic until the fruit begins to mature in late August. Temporal fluctuations and quantitative differences in selected organic acid profiles between fruit of six cranberry genotypes during the growing season were observed. The concentration of benzoic acid in fruit increased while quinic acid decreased throughout fruit development. In general, more rot-resistant genotypes showed higher levels of benzoic acid early in fruit development and more gradual decline in quinic acid levels than that observed in the more rot-susceptible genotypes. We evaluated antifungal activities of selected cranberry constituents and found that most bioactive compounds either had no effects or stimulated growth or reactive oxygen species (ROS secretion of four tested cranberry fruit rot fungi, while benzoic acid and quinic acid reduced growth and suppressed secretion of ROS by these fungi. We propose that variation in the levels of ROS suppressive compounds, such as benzoic and quinic acids, may influence virulence by the fruit rot fungi. Selection for crops that maintain high levels of virulence suppressive compounds could yield new disease resistant varieties. This could represent a new strategy for control of disease caused by necrotrophic pathogens that exhibit a latent or endophytic phase.

  17. Survey of Basal Stem Rot Disease on Oil Palms (Elaeis guineensis Jacq.) in Kebun Bukit Kijang,North Sumatera, Indonesia

    Science.gov (United States)

    Lisnawita; Hanum, H.; Tantawi, A. R.

    2016-08-01

    Basal stem rot disease caused by Ganoderma sp. is a significant disease on oil palm plantations in Indonesia, especially in North Sumatera. Currently, the pathogen does not only attack the plants that have produced (old plants) but also attacks the plants that have not produced in the first generation yet. A survey of the distribution of the basal stem rot disease in the plantation of the community has been completed in order to illustrate the distribution and the incidence of the basal stem rot disease in 5 locations of the oil palm plantation of the community in Desa Bukit Kijang, Region of Asahan, North Sumatera, Indonesia. From the research, it is revealed that the basal stem rot disease has spread to all of the observed locations with the level of disease incidence between 0.71% in Kebun Bukit Kijang 3 to 50% in the 17 years old oil palm in Kebun Bukit Kijang 4 and Bukit Kijang 5. The observable symptoms of the basal stem rot disease are chlorotic leaves, the appearance of fruiting body, collapsed plants, and the existence of holes on the basal stem. The incidence of basal stem rot disease is higher on land due to a high sand content (>50%).

  18. Comparative pathobiology of Heterobasidion annosum during challenge on Pinus sylvestris and Arabidopsis roots: an analysis of defensin gene expression in two pathosystems.

    Science.gov (United States)

    Jaber, Emad; Xiao, Chaowen; Asiegbu, Fred O

    2014-03-01

    Heterobasidion annosum is widely known as a major root and butt rot pathogen of conifer trees, but little information is available on its interaction with the roots of herbaceous angiosperm plants. We investigated the infection biology of H. annosum during challenge with the angiosperm model Arabidopsis and monitored the host response after exposure to different hormone elicitors, chemicals (chitin, glucan and chitosan) and fungal species that represent diverse basidiomycete life strategies [e.g., pathogen (H. annosum), saprotroph (Stereum sanguinolentum) and mutualist (Lactarius rufus)]. The results revealed that the tree pathogen (H. annosum) and the saprotroph (S. sanguinolentum) could infect the Col-8 (Columbia) ecotype of Arabidopsis in laboratory inoculation experiments. Germinated H. annosum spores had appressorium-like penetration structures attached to the surface of the Arabidopsis roots. Subsequent invasive fungal growth led to the disintegration of the vascular region of the root tissues. Progression of root rot symptoms in Arabidopsis was similar to the infection development that was previously documented in Scots pine seedlings. Scots pine PsDef1 and Arabidopsis DEFLs (AT5G44973.1) and PDF1.2 were induced at the initial stage of the infection. However, differences in the expression patterns of the defensin gene homologs from the two plant groups were observed under various conditions, suggesting functional differences in their regulation. The potential use of the H. annosum-Arabidopsis pathosystem as a model for studying forest tree diseases is discussed. PMID:24366684

  19. ROOT User Workshop 2013

    CERN Document Server

    2013-01-01

    Since almost two decades, ROOT has established itself as the framework for HENP data processing and analysis. The LHC upgrade program and the new experiments being designed at CERN and elsewhere will pose even more formidable challenges in terms of data complexity and size. The new parallel and heterogeneous computing architectures that are either announced or already available will call for a deep rethinking of the code and the data structures to be exploited efficiently. This workshop, following from a successful series of such events, will allow you to learn in detail about the new ROOT 6 and will help shape the future evolution of ROOT.

  20. Occuring and preventing and curing of soybean root maggot and root rot%大豆根潜蝇及根腐病的发生与防治

    Institute of Scientific and Technical Information of China (English)

    蔡红

    2001-01-01

    近年来,随着大豆播种面积的增长,受病虫危害日趋严重.特别是大豆根潜蝇(又名根蛆)与根腐病共同发生危害,严重影响大豆的生产.综合防治技术主要手段是三年以上轮作,适时播种及种衣荆拌种等措施.

  1. The Black Studies Boondoggle

    Science.gov (United States)

    Long, Richard A.

    1970-01-01

    Indicates tendencies dangerous to the basic purpose of Black Studies, and identifies four external challeges--imperialism, paternalism, nihilism, and materialism. An internal challenge is considered to be the use of European and Establishment constructs to analyze black reality. (DM)

  2. Quantitative measurements of root water uptake and root hydraulic conductivities

    Science.gov (United States)

    Zarebanadkouki, Mohsen; Javaux, Mathieu; Meunier, Felicien; Couvreur, Valentin; Carminati, Andrea

    2016-04-01

    How is root water uptake distributed along the root system and what root properties control this distribution? Here we present a method to: 1) measure root water uptake and 2) inversely estimate the root hydraulic conductivities. The experimental method consists in using neutron radiography to trace deuterated water (D2O) in soil and roots. The method was applied to lupines grown aluminium containers filled with a sandy soil. When the lupines were 4 weeks old, D2O was locally injected in a selected soil regions and its transport was monitored in soil and roots using time-series neutron radiography. By image processing, we quantified the concentration of D2O in soil and roots. We simulated the transport of D2O into roots using a diffusion-convection numerical model. The diffusivity of the roots tissue was inversely estimated by simulating the transport of D2O into the roots during night. The convective fluxes (i.e. root water uptake) were inversely estimating by fitting the experiments during day, when plants were transpiring, and assuming that root diffusivity did not change. The results showed that root water uptake was not uniform along the roots. Water uptake was higher at the proximal parts of the lateral roots and it decreased by a factor of 10 towards the distal parts. We used the data of water fluxes to inversely estimate the profile of hydraulic conductivities along the roots of transpiring plants growing in soil. The water fluxes in the lupine roots were simulated using the Hydraulic Tree Model by Doussan et al. (1998). The fitting parameters to be adjusted were the radial and axial hydraulic conductivities of the roots. The results showed that by using the root architectural model of Doussan et al. (1998) and detailed information of water fluxes into different root segments we could estimate the profile of hydraulic conductivities along the roots. We also found that: 1) in a tap-rooted plant like lupine water is mostly taken up by lateral roots; (2) water

  3. Genetic association among root morphology, root quality and root yield in ashwagandha (Withania somnifera

    Directory of Open Access Journals (Sweden)

    Kumar Ramesh R.

    2011-01-01

    Full Text Available Ashwagandha (Withania somnifera is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant and crude fiber content exhibited strong association among them and showed significant positive genotypic correlation with yield. Starch-fiber ratio (SFR, determinant of brittle root texture showed strong negative association with root yield. The total alkaloid content had positive genotypic correlation with root yield. So genetic upgradation should aim at optimum balance between two divergent groups of traits i.e. root yield traits (root morphometric traits and crude fiber content and root textural quality traits (starch content and SFR to develop superior genotypes with better yield and quality.

  4. Biological Control Of The Egyptian Brown Rot In Potato (Solanum Tuberosum L.)

    International Nuclear Information System (INIS)

    Pseudomonas fluorescence, P. aeruginosa, Bacillus subtillus and streptomyces spp. Were used in control of Ralstonia solanacearum, the casual agent of brown rot in potato. In vitro, antagonistic activities showed that streptomyces spp. was the most antagonistic followed by P. fluorescence, Bacillus subtilus and P. aeruginosa respectively. Also, in vivo, biological control of R. solanacearum showed that Streptomyces spp. was found to reduce the percentage of brown rot infection to 5% followed by P. fluorescence, Bacillus subtilus and P. aeruginosa reducing the percentage of infection to 15 , 25 and 40%, respectively. Also, the disease severity when using Streptomyces spp. and P. fluorescence was reduced from 5 to 1 and reduced from 5 to 2 when using Bacillus subtilus and P. aeruginosa.

  5. Hybrid integration of Fabry-Pérot cavity with waveguide photodetector on silicon substrate

    Science.gov (United States)

    Hu, Fuquan; Huang, Yongqing; Ren, Xiaomin; Duan, Xiaofeng; Zhang, Xu; Fan, Xinye; Wang, Wei; Shang, Yufeng; Cai, Shiwei

    2013-06-01

    This paper demonstrated a novel device which was fabricated by the integration of a Fabry-Pérot cavity with waveguide photodetectors on silicon substrate. The design of this device integrates two functions on a single semiconductor chip, which is a current trend to make the compact on-chip photonic system. Due to the introduction of waveguide photodetectors, the tradeoff between efficiency and bandwidth could be improved and these two important factors could be specified almost independently. The Fabry-Pérot cavity was grown by metal-organic chemical vapor deposition (MOCVD), which was used for wavelength selectivity. The waveguide photodetector fabricated by the wet etching technique was used for light detection. The peak wavelength of the hybrid integrated device was at 1538 nm. The full-width at half-maximum was about 0.3 nm, and a dark current of 3.2 nA was achieved at the reverse bias of 3.0 V.

  6. Biological decolourisation of pulp mill effluent using white rot fungus Trametes versicolor.

    Science.gov (United States)

    Srinivasan, S V; Murthy, D V S; Swaminathan, T

    2012-07-01

    The conventional biological treatment methods employed in the pulp and paper industries are not effective in reducing the colour and chemical oxygen demand (COD). The white-rot fungi are reported to have the ability to biodegrade the lignin and its derivatives. This paper is focused on the biological treatment of pulp mill effluent from a bagasse-based pulp and paper industry using fungal treatment. Experiments were conducted using the white rot fungus, Trametes versicolor in shake flasks operated in batch mode with different carbon sources. The decolourisation efficiencies of 82.5% and 80.3% were obtained in the presence of 15 g/L and 5 g/L of glucose and sucrose concentrations respectively with a considerable COD reduction. The possibility of reusing the grown fungus was examined for repeated treatment studies.

  7. 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......-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...... against the dry rot isolates. These wood preservatives are less toxic toward the environment than traditional copper based preservatives....

  8. Dynamics of black holes

    OpenAIRE

    Hayward, Sean A.

    2008-01-01

    This is a review of current theory of black-hole dynamics, concentrating on the framework in terms of trapping horizons. Summaries are given of the history, the classical theory of black holes, the defining ideas of dynamical black holes, the basic laws, conservation laws for energy and angular momentum, other physical quantities and the limit of local equilibrium. Some new material concerns how processes such as black-hole evaporation and coalescence might be described by a single trapping h...

  9. Noncommutative black holes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-DomInguez, J C [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); RamIrez, C [Facultad de Ciencias FIsico Matematicas, Universidad Autonoma de Puebla, PO Box 1364, 72000 Puebla (Mexico); Sabido, M [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico)

    2007-11-15

    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole.

  10. Black holes without firewalls

    Science.gov (United States)

    Larjo, Klaus; Lowe, David A.; Thorlacius, Larus

    2013-05-01

    The postulates of black hole complementarity do not imply a firewall for infalling observers at a black hole horizon. The dynamics of the stretched horizon, that scrambles and reemits information, determines whether infalling observers experience anything out of the ordinary when entering a large black hole. In particular, there is no firewall if the stretched horizon degrees of freedom retain information for a time of the order of the black hole scrambling time.

  11. Relationship between potassium chloride suppression of corn stalk rot and soil microorganism characteristics

    Institute of Scientific and Technical Information of China (English)

    LIU Xiaoyan; JIN Jiyun; HE Ping; LIU Hailong; LI Wenjuan

    2007-01-01

    Observations from a site-fixed field trial of 12 years in Jilin Province show that potassium chloride (KC1)application has a significant positive influence on corn stalk rot incidence.Incubation experiments were conducted to study the effects of KC1 and soil extracts on the growth of Fusarium graminearum,the most common stalk rot fungi in this area,and the population changes in rhizosphere fungi,bacteria and actinomyces at different growth stages of corn.The results show that KC1 addition to the potato dextrose agar (PDA) medium could not directly suppress Fusarium graminearum development.Soil extracts from soil samples taken from the field plots with and without KC1 application affected Fusarium graminearum development,with soil extracts with KC1 treatments suppressing Fusarium graminearum development more significantly,compared with that from the KC1-free treatment.These results indicate that soil extracts play a role in the interaction between corn and Fusarium graminearum.Long-term KC1 application may increase the populations of rhizosphere fungi and actinomyces in the early growth stages,while there is no significant difference in the number of bacteria in rhizosphere among the treatments.Also,the populations of rhizosphere fungi are negatively correlated with the incidence of stalk rot in the early growth stages of corn.The sensitive infection stages of pathogen to corn consist of the stages when there is significant difference in the populations of rhizosphere fungi and actinomyces.The change of microorganism populations (especially fungi) in soil may be associated with the incidence decrease and is one of the mechanisms of KC1 suppressing corn stalk rot.

  12. Chemical Characterization of Different Sumac and Pomegranate Extracts Effective against Botrytis cinerea Rots

    OpenAIRE

    Romeo, Flora V.; Gabriele Ballistreri; Simona Fabroni; Sonia Pangallo; Maria Giulia Li Destri Nicosia; Leonardo Schena; Paolo Rapisarda

    2015-01-01

    Pomegranate (Punica granatum L.) peel and sumac (Rhus coriaria L.) fruit and leaf extracts were chemically characterized and their ability to inhibit table grape (cv. Italia) rots caused by Botrytis cinerea was evaluated on artificially inoculated berries. Different extraction methods were applied and extracts were characterized through Ultra Fast High Performance Liquid Chromatography coupled to Photodiode array detector and Electrospray ionization Mass spectrometer (UPLC-PDA-ESI/MSn) for th...

  13. Using a grass substrate to compare decay among two clades of brown rot fungi.

    Science.gov (United States)

    Kaffenberger, Justin T; Schilling, Jonathan S

    2013-10-01

    Interest in the mechanisms of wood-degrading fungi has grown in tandem with lignocellulose bioconversion efforts, yet many potential biomass feedstocks are non-woody. Using corn stover (Zea mays) as a substrate, we tracked degradative capacities among brown rot fungi from the Antrodia clade, including Postia placenta, the first brown rot fungus to have its genome sequenced. Decay dynamics were compared against Gloeophyllum trabeum from the Gloeophyllum clade. Weight loss induced by P. placenta (6.2 %) and five other Antrodia clade isolates (average 7.4 %) on corn stalk after 12 weeks demonstrated inefficiency among these fungi, relative to decay induced by G. trabeum (44.4 %). Using aspen (Populus sp.) as a woody substrate resulted in, on average, a fourfold increase in weight loss induced by Antrodia clade fungi, while G. trabeum results matched those on stover. The sequence and trajectories of chemical constituent losses differed as a function of substrate but not fungal clade. Instead, chemical data suggest that characters unique to stover limit decay by the Antrodia clade, rather than disparities in growth rate or extractives toxicity. High p-coumaryl lignin content, lacking the methoxy groups characteristically cleaved during brown rot, is among potential rate-distinguishing characters in grasses. This ineptitude among Antrodia clade fungi on grasses was supported by meta-analysis of other unrelated studies using grass substrates. Concerning application, results expose a problem if adopting the strategy of the model decay fungus P. placenta to treat corn stover, a widely available plant feedstock. Overall, the results insinuate phylogenetically distinct modes of brown rot and demonstrate the benefit of using non-woody substrates to probe wood degradation mechanisms. PMID:23917637

  14. Wood Degradation by White Rot Fungi: Cytochemical Studies Using Lignin Peroxidase-Immunoglobulin-Gold Complexes

    OpenAIRE

    Garcia, Susana; Latge, Jean Paul; Prevost, Marie Christine; Leisola, Matti

    1987-01-01

    Using an anti-lignin peroxidase antiserum-protein A-gold complex, we found lignin peroxidase mainly intracellularly in several white rot fungi colonizing sawdust under laboratory conditions. This enzyme was also present in fungi found in naturally decayed wood. However, in all cases, lignin peroxidase was located mainly inside the fungal cells. Labeled lignin peroxidase did not bind to the lignocellulosic samples tested, with the exception of poplar milled-wood lignin. These results are discu...

  15. Lignin as a facilitator, not a barrier, during saccharification by brown rot fungi

    Energy Technology Data Exchange (ETDEWEB)

    Schilling, Jonathan S. [Univ. of Minnesota, Minneapolis, MN (United States); Tschirner, Ulrike [Univ. of Minnesota, Minneapolis, MN (United States); Blanchette, Robert A [Univ. of Minnesota, Minneapolis, MN (United States); Filley, Timothy [Purdue Univ., West Lafayette, IN (United States)

    2012-11-28

    This research focused on the biology of a group of wood-degrading fungi that cause brown rot in wood, with particular attention to the potential to mimic this biological approach ex situ for bioprocessing lignocellulosic biomass. Supported by the long-standing theory that these fungi use a two-step oxidative/enzymatic approach during brown rot, our team’s objectives were as follows: 1) to determine the discrete timing of lignin modifications, 2) to correlate these alterations with biocatalyst efficiency and ingress into plant cell walls, and 3) to reproduce modifications prior to saccharification for efficient bioprocessing. The core findings of our research were that 1) lignin modifications occur nearly coincident with enzyme secretion during brown rot and 2) there is no specificity to the benefit that a brown rot pretreatment has on the efficacy of cellulases – it is a general enhancement best predicted by chemical changes to lignin and side-chain hemicellulose sugars. In our work, this meant we could attain and predict broad improvements in saccharification using commercial cellulase cocktails, in some cases more than three-fold of that in untreated biomass. This project was completed with minimal variance from the original project management plan (PMP), resulting in fourteen presentations and posters, four peer-reviewed publications, and one additional publication now in review. The publications have been valuable to other scientists working toward similar goals and have been cited in thirteen peer-reviewed publications written by others since 2010. We are working with ADM to advance application options for industry, building on the lessons learned during this DOE award period.

  16. Rhizoctonia solani as a component in the bottom rot complex of glasshouse lettuce

    OpenAIRE

    Kooistra, T

    1983-01-01

    The basal parts of maturing glasshouse lettuce can be attacked by several soil fungi, which cause bottom rot. Until recently quintozene was generally applied against this disease complex. The study of the causal fungi - especially Rhizoctonia solani - and their control was undertaken in view of the need for quintozene replacing fungicides.A survey revealed that Botrytis cinerea was the most frequently observed pathogen, especially in winter crops. The incidence of Sclerotinia minor, Sclerotin...

  17. Treatment of micropollutants in municipal wastewater using white-rot fungi

    OpenAIRE

    Margot, Jonas; Vargas, Micaela; Contijoch, Andreu; Barry, David Andrew; Holliger, Christof

    2014-01-01

    Treatment of micropollutants such as pharmaceuticals and pesticides in municipal wastewater is challenging due to their very low concentrations (ng/l to µg/l), their relatively low biodegradability, and their different physico-chemical characteristics. One potential way to improve micropollutant biodegradation in wastewater treatment plant (WWTP) effluent is by using microorganisms such as white-rot fungi that produce powerful unspecific oxidative exo-enzymes (laccase, peroxidase) that are ab...

  18. Pectinase Activity of Anaerobic and Facultatively Anaerobic Bacteria Associated with Soft Rot of Yam (Diascorea rotundata)

    OpenAIRE

    Obi, Samuel K. C.

    1981-01-01

    Anaerobic and facultatively anaerobic bacteria associated with soft rot of yam (Diascorea rotundata) were isolated by the looping-out method and found to consist of Clostridium (three isolates), Corynebacterium (three isolates), Vibrio (one isolate), and Bacillus lentus (one isolate). Enzyme assay for hydrolase, lyase, and pectinesterase activities by the cup-plate method showed that except for Vibrio sp., B. lentus, and two isolates of Corynebacterium no pectinase activity could be detected ...

  19. Diversity and biological control of Sclerotium rolfsii, causal agent of stem rot of groundnut

    OpenAIRE

    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 mostly rely on the extensive use of fungicides and on cultural practices. Both methods are not always effective and repeated fungicide use can lead to resistance development in the pathogen population. To further impro...

  20. Degradation of selected agrochemicals by the white rot fungus Trametes versicolor

    OpenAIRE

    Mir-Tutusaus, Josep Anton; Caminal i Saperas, Glòria; Sarrà i Adroguer, Montserrat

    2014-01-01

    Use of agrochemicals is a worldwide practice that exerts an important effect on the environment; therefore the search of approaches for the elimination of such pollutants should be encouraged. The degradation of the insecticides imiprothrin (IP) and cypermethrin (CP), the insecticide/nematicide carbofuran (CBF) and the antibiotic of agricultural use oxytetracycline (OTC) were assayed with the white rot fungus Trametes versicolor. Experiments with fungal pellets demonstrated extensive degradat...