Effects on Glomus mosseae Root Colonization by Paenibacillus polymyxa and Paenibacillus brasilensis Strains as Related to Soil P-Availability in Winter Wheat

International Nuclear Information System (INIS)

Arthurson, V; Granhall, U; Derlund, L; Hjort, K; Muleta, D

2011-01-01

Greenhouse experiments were conducted to assess the effects of inoculating winter wheat (Triticum aestivum) with plant growth promoting rhizobacteria (PGPR) of the genus Paenibacillus under phosphate P-limited soil conditions in the presence or absence of the arbuscular mycorrhizal fungus (AMF) Glomus mosseae. Four P. polymyxa strains and one P. brasilensis strain were compared at two cell concentrations (10 6 and 10 8 cells g -1 seeds) of inoculation, and surface sterilized AMF spores were added to pots. Mycorrhizal root colonization, plant growth, and plant uptake of phosphorus were analyzed. Bacterial phosphate solubilization was examined separately in vitro. Most P. polymyxa strains, isolated from wheat, had dramatic effects per se on root growth and root P-content. No treatment gave significant effect on shoot growth. AMF root colonization levels and total plant uptake of P were much stimulated by the addition of most P. polymyxa strains. The AM fungus alone and the P. brasilensis, alone or in combination with the fungus, did not affect total plant P-levels. Our results indicate that practical application of inoculation with plant host-specific rhizobacteria (i.e., P. polymyxa) could positively influence uptake of phosphorus in P-

Arbuscular mycorrhizal fungi improve the growth of olive trees and ...

African Journals Online (AJOL)

Two native Algerian mycorrhizal fungi (Glomus mosseae and Glomus intraradices) were tested for their effect on the growth of micropropagated olive tree (Olea europaea L.). The effect of inoculation of plantlets with G. mosseae was also compared with chemical fertilization using osmocote. Specific molecular techniques ...

Arbuscular mycorrhizal fungi improve the growth of olive trees and ...

African Journals Online (AJOL)

STORAGESEVER

quality olive plants. To study the potential of the mycorrhizal fungi Glomus mosseae and Glomus intraradices to stimulate the growth of micropropagated olive plants and to compare their ... phosphate, 15% potassium oxide, 2% magnesium oxide, 4.5% sulphur, 0.02% ..... Our results indicate the feasibility of G. mosseae and.

Influence of mycorrhizal inoculation on alley cropped farms in a ...

African Journals Online (AJOL)

The use of Arbuscular mycorrhizal (AM) fungi under farmers' conditions was tried at Ajibode Village, a humid tropical environment on maize/cassava intercropped farms in an alley cropping system. Four species of AM fungi (Glomus clarum, Glomus mosseae Glomus etunicatum and Acaulospora dilatata) were used in ...

Glomus tumor of penis- A rare case

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Madhuri S. Kate

2013-01-01

Full Text Available Glomus tumors are rare, painful, and benign soft tissue tumors of the skin arising from the glomus body, an arteriovenous thermoregulatory structure. This lesion is usually found on the extremities. Glomus tumor involving the external genital organs including penis is extremely rare. Until now, only few cases have been reported in the available literature. A 22 year old male patient presented with a painful nodule over the penis. The pathologic diagnosis was glomus tumor of the glans penis. We report herewith a case of glomus tumor of penis diagnosed on histopathologic examination. Glomus tumor, being a benign neoplasm, complete extirpation of the glomus tumor is the treatment of choice.

Genetic structure of arbuscular mycorrhizal populations in fallow and cultivated soils

DEFF Research Database (Denmark)

Rosendahl, Søren; Matzen, Hans

2008-01-01

protein-coding genes GmFOX2 and GmTOR2 were used as co-dominant genetic markers together with the large subunit (LSU) rDNA. The gene diversity and genetic structure of Glomus mosseae, Glomus geosporum and Glomus caledonium were compared within and between the fields. •  Spores of G. caledonium and G...

Atypically localized glomus tumors

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Meric Ugurlar

2016-12-01

Conclusion: When a painful mass is found in the body, glomus tumors should be kept in mind. The consideration of symptoms, including pain, temperature sensitivity, point tenderness, and discoloration, common characteristics of glomus tumors, may aid diagnosis. [Hand Microsurg 2016; 5(3.000: 112-117

Response of Sesbania grandiflora to Inoculation of Soil with Vesicular-Arbuscular Mycorrhizal Fungi.

Science.gov (United States)

Habte, M; Aziz, T

1985-09-01

A greenhouse experiment was conducted to determine the influence of two tropical isolates of Glomus fasciculatum and Glomus mosseae on the nutrient uptake and growth of Sesbania grandiflora. Inoculation of sterile soil with the fungi significantly improved growth and nutrient uptake by S. grandiflora, but the response of the legume was markedly better when the soil was inoculated with G. fasciculatum than when it was inoculated with G. mosseae. Nutrient uptake and growth of S. grandiflora in nonsterile soil was also significantly stimulated by inoculation, but the legume did not respond differently to the two endophytes under this condition.

Evaluation of some fungicides on mycorrhizal symbiosis between two Glomus species from commercial inocula and Allium porrum L. seedlings

Energy Technology Data Exchange (ETDEWEB)

Hernandez-Dorrego, A.; Mestre Pares, J.

2010-07-01

This paper reports the effect of twenty-five commonly used fungicides in agriculture on two arbuscular mycorrhizal fungi (AMF) present in commercial products of ATENS, S.L.: Glomus intra radices (Schenck and Smith) and Glomus mosseae [(Nicol. and Gerd.) Gerdemann and Trappe], forming the symbiosis with leek plants. Systemic fungicides (Aliette, Beltanol, Caddy 10, Forum, Moncut, Ortiva, Previcur, Ridomil Gold MZ, Ridomil Gold SL, Rubigan, Sinthane, Stroby, Swich, Tachigarem, Teldor, Topas 10 EC, Frupica) and non systemic fungicides (Daconil 75%, Ditiver, Euparem, INACOP, Octagon, Parmex, Terrazole and Metaram), started to be applied to soil and leaves at recommended concentrations and frequencies 4 weeks after transplant and AMF inoculation. The effect of the fungicides was assessed by comparing treated and untreated plants that were inoculated with the AMF through quantification of root mycorrhizal colonization. Among the fungicides applied to the soil, Octagon, Ditiver, Parmex and Metaram virtually eliminated the mycorrhizal symbiosis in treated plants, while the mycorrhizal colonization was not affected by the soil treatment with Beltanol, INACOP and Previcur. Three fungicides of foliar recommended application: Rubigan, Frupica, and Sinthane, strongly inhibited mycorrhizal colonization, but Aliette, Forum, Teldor, Swich and Ortiva, did not seem to reduce it substantially. In addition, the work describes the individual effect of each fungicide applied on both, foliage and soil. (Author) 29 refs.

Development and amplification of multiple co-dominant genetic markers from single spores of arbuscular mycorrhizal fungi by nested multiplex PCR

DEFF Research Database (Denmark)

Holtgrewe-Stukenbrock, Eva; Rosendahl, Søren

2005-01-01

Multiple co-dominant genetic markers from single spores of the arbuscular mycorrhizal (AM) fungi Glomus mosseae, Glomus caledonium, and Glomus geosporum were amplified by nested multiplex PCR using a combination of primers for simultaneous amplification of five loci in one PCR. Subsequently, each...... marker was amplified separately in nested PCR using specific primers. Polymorphic loci within the three putative single copy genes GmFOX2, GmTOR2, and GmGIN1 were characterized by sequencing and single strand conformation polymorphisms (SSCP). Primers specific for the LSU rDNA D2 region were included...... are homokaryotic. All isolates of G. mosseae had unique genotypes. The amplification of multiple co-dominant genetic markers from single spores by the nested multiplex PCR approach provides an important tool for future studies of AM fungi population genetics and evolution....

Mycorrhizal Glomus spp. vary in their effects on the dynamics and turnover of fine alfalfa (Medicago sativa L.) roots

International Nuclear Information System (INIS)

Ren, A.; Waly, N.; Chunhui, M.; Zhang, Q.; Liu, H.; Yang, J.

2016-01-01

The distribution of fine roots in the soil profile has important implications related to water and nutrient uptake. The Objective of this study was to compare the effects of different arbuscular mycorrhizal fungi (AMF) on the fine root dynamics of Medicago sativa L. cv. Sanditi. We used minirhizotrons to observe changes in fine root length density (FRLD, mm/cm2) and fine root surface area density (FRSAD, mm2/cm2) during the growing season. Fine root P concentrations and turnover rate were also measured. The colonization rate of fine roots varied depending on the AMF species. Colonization rates were highest when roots were inoculated with Glomus mosseae and lowest when roots were inoculated G. intraradices. Inoculation with AMF significantly increased both FRLD and FRSAD. G. versiforme increased FRLD and FRSAD most, whereas G. mosseae had the least effect. Inoculation with AMF also decreased fine root turnover rates. Inoculation with a mixture of AMF species increased fine root turnover and P concentrations more than inoculation with a single AMF species. Fine root length density increased to a maximum on Aug. 6 and then decreased. In comparison, FRSAD exhibited two peaks during the growing season. Overall, the Results indicated that inoculation with AMF can significantly promote fine root growth and P uptake by alfalfa growing on soil with low P availability. The AMF may preserve fine root function late in the growing season. (author)

Concomitant Glomus Tumor with CRPS in the Hand.

Science.gov (United States)

Jeong, Hyeong Jun; Kim, Chan Mi; Yoon, Duck Mi; Yoon, Kyung Bong

2013-07-01

Glomus tumors are benign tumors that account for 1% to 5% of all soft tissue tumors of the hand and are characterized by a triad of sensitivity to cold, localized tenderness and severe paroxysmal pain. Paroxysmal pain is a symptom common not only in glomus tumors but also in CRPS, and the hand is one of the commonly affected sites in patients with both glomus tumors and CRPS. Therefore, it is not easy to clinically diagnose glomus tumors superimposed on already affected region of CRPS patients. We report a case of glomus tumor concomitantly originating with CRPS at the hand.

Role of mycorrhizal fungi and salicylic acid in salinity tolerance of ...

African Journals Online (AJOL)

Most researchers showed that inoculation of plants with mycorrhizal fungi and using salicylic acid increase tolerance of plants due to salinity. In this study, the effect of mycorrhizal fungi, including Glomus mosseae, Glomus intraradices, and salicylic acid (0.2 mM) on tolerance of green basil (Ocimum basilicum L.) to salinity ...

Protection of olive planting stocks against parasitism of root-knot nematodes by arbuscular mycorrhizal fungi

OpenAIRE

Castillo, Pablo; Nico, Andrés I.; Azcón González de Aguilar, Concepción; Río Rincón, C. del; Calvet, Cinta; Jiménez-Díaz, Rafael M.

2006-01-01

The effects were investigated, under controlled conditions, of single and joint inoculation of olive planting stocks cvs Arbequina and Picual with the arbuscular mycorrhizal fungi (AMF) Glomus intraradices, Glomus mosseae or Glomus viscosum, and the root-knot nematodes Meloidogyne incognita and Meloidogyne javanica, on plant performance and nematode infection. Establishment of the fungal symbiosis significantly increased growth of olive plants by 88·9% within a range of 11·9–214·0%, ...

Correlations of Glomalin Contents and PAHs Removal in Alfalfa-vegetated Soils with Inoculation of Arbuscular Mycorrhizal Fungi

OpenAIRE

YANG Zhen-ya; ZONG Jiong; ZHU Xue-zhu; LING Wan-ting

2016-01-01

The correlations of glomalin contents and removal of phenanthrene and pyrene as representative polycyclic aromatic hydrocarbons (PAHs) in soils with inoculation of arbuscular mycorrhizal fungi(AMF) were investigated. The test AMF included Glomus etunicatum(Ge), Glomus mosseae(Gm), and Glomus lamellosum(Gla), and the host plant was alfalfa(Medicago sativa L.). The AMF hyphal density and contents of easily extractable glomalin and total glomalin in AMF-inoculated soils were observed to increase...

Growth, cadmium uptake and accumulation of maize (Zea mays L.) under the effects of arbuscular mycorrhizal fungi.

Science.gov (United States)

Liu, Lingzhi; Gong, Zongqiang; Zhang, Yulong; Li, Peijun

2014-12-01

The effects of three arbuscular mycorrhizal fungi isolates on Cd uptake and accumulation by maize (Zea mays L.) were investigated in a planted pot experiment. Plants were inoculated with Glomus intraradices, Glomus constrictum and Glomus mosseae at three different Cd concentrations. The results showed that root colonization increased with Cd addition during a 6-week growth period, however, the fungal density on roots decreased after 9-week growth in the treatments with G. constrictum and G. mosseae isolates. The percentage of mycorrhizal colonization by the three arbuscular mycorrhizal fungi isolates ranged from 22.7 to 72.3%. Arbuscular mycorrhizal fungi inoculations decreased maize biomass especially during the first 6-week growth before Cd addition, and this inhibitory effect was less significant with Cd addition and growth time. Cd concentrations and uptake in maize plants increased with arbuscular mycorrhizal fungi colonization at low Cd concentration (0.02 mM): nonetheless, it decreased at high Cd concentration (0.20 mM) after 6-week growth period. Inoculation with G. constrictum isolates enhanced the root Cd concentrations and uptake, but G. mosseae isolates showed the opposite results at high Cd concentration level after 9 week growth period, as compared to non-mycorrhizal plants. In conclusion, maize plants inoculated with arbuscular mycorrhizal fungi were less sensitive to Cd stress than uninoculated plants. G. constrictum isolates enhanced Cd phytostabilization and G. mosseae isolates reduced Cd uptake in maize (Z. mays L.).

Radiosurgery of Glomus Jugulare Tumors: A Meta-Analysis

International Nuclear Information System (INIS)

Guss, Zachary D.; Batra, Sachin; Limb, Charles J.; Li, Gordon; Sughrue, Michael E.; Redmond, Kristin; Rigamonti, Daniele; Parsa, Andrew T.; Chang, Steven; Kleinberg, Lawrence; Lim, Michael

2011-01-01

Purpose: During the past two decades, radiosurgery has arisen as a promising approach to the management of glomus jugulare. In the present study, we report on a systematic review and meta-analysis of the available published data on the radiosurgical management of glomus jugulare tumors. Methods and Materials: To identify eligible studies, systematic searches of all glomus jugulare tumors treated with radiosurgery were conducted in major scientific publication databases. The data search yielded 19 studies, which were included in the meta-analysis. The data from 335 glomus jugulare patients were extracted. The fixed effects pooled proportions were calculated from the data when Cochrane's statistic was statistically insignificant and the inconsistency among studies was 36 months. In these studies, 95% of patients achieved clinical control and 96% achieved tumor control. The gamma knife, linear accelerator, and CyberKnife technologies all exhibited high rates of tumor and clinical control. Conclusions: The present study reports the results of a meta-analysis for the radiosurgical management of glomus jugulare. Because of its high effectiveness, we suggest considering radiosurgery for the primary management of glomus jugulare tumors.

Malignant Glomus Tumor of the Peritoneum: Case Report

Energy Technology Data Exchange (ETDEWEB)

Baleato-González, Sandra; García-Figueiras, Roberto; Trujillo-Ariza, Maria Virginia [Department of Radiology, Complexo Hospitalario Universitario de Santiago de Compostela, Choupana s/n, 15701 Santiago de Compostela (A Coruña) (Spain); Carrera-Álvarez, Juan Jose [Department of Pathology, Complexo Hospitalario Universitario de Santiago de Compostela, Choupana s/n, 15701 Santiago de Compostela (A Coruña) (Spain)

2014-07-01

Glomus tumors are usually benign tumors that occur in the skin and soft tissues of the extremities. Visceral locations, such as stomach, intestines or lung, are extremely rare because glomus bodies are rare or absent in these organs. This report describes our experience in a 47-year-old woman diagnosed with a peritoneal malignant glomus tumor. This finding has not been previously reported.

Malignant Glomus Tumor of the Peritoneum: Case Report

International Nuclear Information System (INIS)

Baleato-González, Sandra; García-Figueiras, Roberto; Trujillo-Ariza, Maria Virginia; Carrera-Álvarez, Juan Jose

2014-01-01

Glomus tumors are usually benign tumors that occur in the skin and soft tissues of the extremities. Visceral locations, such as stomach, intestines or lung, are extremely rare because glomus bodies are rare or absent in these organs. This report describes our experience in a 47-year-old woman diagnosed with a peritoneal malignant glomus tumor. This finding has not been previously reported

Glomus Tumors: Symptom Variations and Magnetic Resonance Imaging for Diagnosis

Directory of Open Access Journals (Sweden)

Ki Weon Ham

2013-07-01

Full Text Available Background The typical clinical symptoms of glomus tumors are pain, tenderness, and sensitivity to temperature change, and the presence of these clinical findings is helpful in diagnosis. However, the tumors often pose diagnostic difficulty because of variations in presentation and the nonspecific symptoms of glomus tumors. To the best of our knowledge, few studies have reported on the usefulness of magnetic resonance imaging (MRI in diagnosing glomus tumors in patients with unspecific symptoms.Methods The inclusion criteria of this study were: having undergone surgery for subungual glomus tumor of the hand, histopathologic confirmation of glomus tumor, and having undergone preoperative MRI. Twenty-one patients were enrolled. The characteristics of the tumors and the presenting symptoms including pain, tenderness, and sensitivity to temperature change were retrospectively reviewed.Results Five out of 21 patients (23% did not show the typical glomus tumor symptom triad because they did not complain of pain provoked by coldness. Nevertheless, preoperative MRI showed well-defined small soft-tissue lesions on T1- and T2-weighted images, which are typical findings of glomus tumors. The tumors were completely resected and confirmed as glomus tumor histopathologically.Conclusions Early occult lesions of glomus tumor in the hand may not be revealed by physical examination because of their barely detectable symptoms. Moreover, subungual lesions may be particularly difficult to evaluate on physical examination. Our cases showed that MRI offers excellent diagnostic information in clinically undiagnosed or misdiagnosed patients. Preoperative MRI can accurately define the character and extent of glomus tumor, even though it is impalpable and invisible.

Glomus Tumors: Symptom Variations and Magnetic Resonance Imaging for Diagnosis

Directory of Open Access Journals (Sweden)

Ki Weon Ham

2013-07-01

Full Text Available BackgroundThe typical clinical symptoms of glomus tumors are pain, tenderness, and sensitivity to temperature change, and the presence of these clinical findings is helpful in diagnosis. However, the tumors often pose diagnostic difficulty because of variations in presentation and the nonspecific symptoms of glomus tumors. To the best of our knowledge, few studies have reported on the usefulness of magnetic resonance imaging (MRI in diagnosing glomus tumors in patients with unspecific symptoms.MethodsThe inclusion criteria of this study were: having undergone surgery for subungual glomus tumor of the hand, histopathologic confirmation of glomus tumor, and having undergone preoperative MRI. Twenty-one patients were enrolled. The characteristics of the tumors and the presenting symptoms including pain, tenderness, and sensitivity to temperature change were retrospectively reviewed.ResultsFive out of 21 patients (23% did not show the typical glomus tumor symptom triad because they did not complain of pain provoked by coldness. Nevertheless, preoperative MRI showed well-defined small soft-tissue lesions on T1- and T2-weighted images, which are typical findings of glomus tumors. The tumors were completely resected and confirmed as glomus tumor histopathologically.ConclusionsEarly occult lesions of glomus tumor in the hand may not be revealed by physical examination because of their barely detectable symptoms. Moreover, subungual lesions may be particularly difficult to evaluate on physical examination. Our cases showed that MRI offers excellent diagnostic information in clinically undiagnosed or misdiagnosed patients. Preoperative MRI can accurately define the character and extent of glomus tumor, even though it is impalpable and invisible.

Interaction of arbuscular mycorrhizal fungus ( Glomus intraradices ...

African Journals Online (AJOL)

In this research, the effect of two arbuscular mycorrhizal fungal (AMF) inoculation (Glomus intraradices and Glomus etunicatum) on tomato plants growing in nutrient solution with high concentrations of copper were studied. Copper (Cu) is an essential micronutrient for plant growth. In the present study, the effect of copper ...

Glomus Tumor of Thumb Occurring at Unusual Location

African Journals Online (AJOL)

diagnosis of glomus tumour. Although rare, glomus tumour should be considered as differential diagnosis for fingertip ... Figure 1: Radiograph-anteropsterior and lateral view ... nail bed is carefully dissected from the bone until the tumor.

Influence of Inoculation with the Endomycorrhizal Fungi and Trichoderma viride on Morphological and Physiological Growth Parameters of Rauwolfia serpentina Benth. Ex. Kurtz.

Science.gov (United States)

Kaushish, Sunita; Kumar, Aditya; Aggarwal, Ashok; Parkash, Vipin

2012-06-01

Two arbuscular mycorrhizal fungi, Glomus mosseae and Acaulospora laevis either alone or in combination with Trichoderma viride showed the dependence of Rauwolfia serpentina on endomycorrhizal fungi. After 60 days, G. mosseae singly or in combination with Trichoderma viride showed enhanced height increment compared to control plants. Maximum phosphorus content was shown by plants treated with G. mosseae plus T. viride (0.444 ± 2.62) in roots and (0.437 ± 4.71) in shoots. Phosphorus content in roots was more than that in shoots. Chlorophyll content and stomatal conductivity also showed similar trend.

Evaluating effect of biofertilizer on nodulation and soybean (Glycine max L plants growth characteristics under water deficit stress of seed

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M. Tajik Khaveh

2016-05-01

Full Text Available In order to evaluate the effects of biofertilizer on soybean (Glycine max L. seed vigor that produced under water deficit condition and related traits, an experiment was conducted in a factorial layout based of complete randomized block design with four replications at the research greenhouse of Aboureihan campus- Tehran University, Iran. Experimental treatments were include biofertilizer (seed inoculation with Bradyrhizobium japonicum, co-inoculation with Bradyrhizobium japonicum and Pseudomonas fluorescens, co-inoculation with Bradyrhizobium japonicum and Glomus mosseae, Cultivar (Zalta Zalha and Clark×Hobbit line and water deficit stress [irrigation plants after 50 (normal irrigation, 100 (medium stress, 150 (sever stress mm evaporation from pan class A, in parents field]. Results showed that the water deficit stress had negative effects on seed quality and seedling emergence percentage, mean daily seedling emergence, root, leaf and shoot dry weight, number of nodule were decreased. ZaltaZalha cultivar had higher shoot dry weight and number of leaf compared with other cultivars. Applications of biofertilzer was effective on stem diameter, root, leaf and shoot dry weight, number of leaf and nodule and those attributes increased by co-inoculation of Bradyrhizobium japonicum and Glomus mosseae. Also, use of biofertilizer in stress levels was effective on stem dry weight. Stem dry weight was increased by Co-inoculation of cultivar seeds with Bradyrhizobium japonicum and Glomus mosseae.

A Primary Pulmonary Glomus Tumor: A Case Report and Review of the Literature

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Yasushi Ariizumi

2012-01-01

Full Text Available A case of a glomus tumor originating from the lung is reported. A 43-year-old female had undergone resection of a right lung tumor following a clinical diagnosis of carcinoid, sclerosing hemangioma, or other sarcoma. Histologically, the tumor comprised uniform small round to oval cells with centrally located nucleus, a clear cytoplasm, and apparent cell borders. The tumor also showed a focally hemangiopericytomatous pattern with irregularly branching or dilated vessels. Electron microscopy revealed smooth muscle differentiation of the tumor cells. Immunostaining further revealed that the tumor cells expressed smooth muscle actin, h-caldesmon, muscle specific actin (HHF-35, but not cytokeratin, epithelial membrane antigen, synaptophysin, or chromogranin A. Based on these findings, a diagnosis of primary pulmonary glomus tumor was established. Glomus tumors of the lung are very rare and only 21 cases have been reported to date. The histological features of the present tumor and the relevant literature are discussed.

Knee glomangioma: a rare location for a glomus tumor

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Ricardo Gonçalves

2014-12-01

Full Text Available Glomus tumor is a rare, benign neoplasm rising from the glomus apparatus of the skin. It occurs most frequently on fingers and toes and accounts for 1.6% of all soft tissue tumors. Clinical diagnosis may prove difficult if the tumor occurs on an extra digital location. We report a case of a vascular-type glomus tumor (glomangioma found in an atypical location, namely the lateral aspect of the knee joint.

An unusual presentation of a glomus tumour.

LENUS (Irish Health Repository)

Nugent, N

2011-02-01

Glomus tumours are benign, soft tissue tumours, usually of fingertips. Classically they present with severe pain, temperature sensitivity and localised tenderness. The diagnosis is often delayed due to sometimes non-specific symptoms and rarity of the disorder. While usually a clinical diagnosis, imaging may be necessary for diagnosis and localisation. We present a case of glomus tumour of the fingertip with an unusual history.

Alterations of the Antioxidant Enzyme Activities are not General Characteristics of the Colonization Process by Arbuscular Mycorrhizal Fungi Alteraciones de las Actividades de Enzimas Antioxidantes no son Características Generales del Proceso de Colonización por Hongos Micorrízicos Arbusculares

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Yakelin Rodríguez

2012-09-01

Full Text Available Antioxidant system is involved in arbuscular mycorrhizal symbiosis, but its role during the colonization process is still poorly understood. To gain new insights into the role of antioxidant system during root colonization by arbuscular mycorrhizal fungi, the activities of key antioxidant enzymes were evaluated in tomato (Solanum lycopersicum L. roots inoculated with six strains of different genera and species: two Glomus mosseae, Glomus cubense, Glomus intraradices, Glomus sp. and Acaulospora scrobiculata. Glomus cubense and A. scrobiculata strains reached the highest infectivity levels with maximum values of colonization frequency and intensity of 29-10.88% and 18-9.20%, respectively; G. mosseae strains showed an intermediate infectivity, both with 15% of colonization frequency and maximum intensities of 7.647.06%, respectively; while the infectivity levels of Glomus sp. and G. intraradices strains were the lowest with colonization frequency- 13% and intensities- 5.07 and 5.41, respectively. Some activity patterns of peroxidase, superoxide dismutase, and polyphenol oxidase enzymes were not specific for early or late colonization stages neither for the colonization level and type of strain. However, a unique superoxide dismutase-band presents at early colonization and the low level of guaiacol-peroxidase activity at later stages presents in all inoculated roots indicate that these antioxidant responses are independent of colonization degree and strain. Taking together, our data suggest that alterations of the antioxidant enzyme activities are not general characteristics of the colonization process by arbuscular mycorrhizal fungi, probably having the key role on those responses the specific feature of each strain rather than colonization per se.El sistema antioxidante está involucrado en la simbiosis micorrízico-arbuscular, pero su rol durante el proceso de colonización es aún escasamente comprendido. Para esclarecer el papel del sistema

The Effects of Arbuscular-Mycorrhizal Fungi and Phosphorous on Arsenic Uptake by Sunflower Plant in Soils Spiked with Arsenite and Arsenate

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Saeed Bagherifam

2017-01-01

Full Text Available Introduction: Arsenic is a highly toxic metalloid in group 15 of periodic table. The information on environmental behaviour of arsenic, however, is still scarce. Contamination of soils and water with arsenic and antimony due to their widespread industrial application and mining activities has raised serious environmental concerns. Nearly all Arsenic-contaminated soils results from human activities and it has different environmental and sociological impacts. Various strategies and methods have been proposed for environmental management and remediation of contaminated soils. Among all methods, the phytoremediation is receiving more attention due to its cost effective and environmental friendly characteristics. In the case of arsenic contaminated soils, there are effective factors such as soil fertility, nutrients content and microorganisms function, which can improve the uptake of As by plants. Up to now, several studies have been evaluated the effects of symbiotic fungal association in plants on increasing nutrients and toxic elements uptake. Many of authors reported that the mycorrhizal symbiosis increases the uptake of toxic elements in root and shoot of plants and consequently improve the efficacy of phytostabilization and phytoextraction processes. There are conflicting results about the effect of arbuscular- mycorrhizal fungi (AMF on As uptake by various plants. Chen et al. (4 found that Glomus mosseae symbiosis with plant reduces As concentration and enhance phosphorus content in shoot and root of plant. Whilst Cozzolino et al. (7 reported that the AMF increases as concentration in shoot and root of cabbage. Phosphorus has important role on mycorrhizal symbiosis and also As uptake by plants. Therefore, current study was conducted to evaluated effect of Glomus intraradices and Glomus mosseae symbiosis with sunflower and also soil phosphorus concentration on uptake of arsenic from arsenite and arsenate contaminated soils. Materials and

Uptake of different forms of nitrogen by hyphae of arbuscular mycorrhizal fungi

International Nuclear Information System (INIS)

Li Xia; Zhang Junling

2007-01-01

A two-compartment incorporating air-gap device and 15 N-labeling technique was used to investigate the uptake of different forms of N by arbuscular mycorrhizal fungi (AMF). Maize (Zea mays L.) was in association with Glomus mosseae, or Glomus intraradices. Solutions labeled with different forms of 15 N were supplied to the hyphae compartment 48 h before harvesting. The results showed that the uptake capability of 15 N varied with fungi species and N forms supplied. Percentage of 15 N taken up over 48 h by G. intraradices was higher than that by G. mosseae. The uptake capability of 15 N by AMF was in the order of 15 NH 4 + > 15 N-Gln> 15 N-Gly> 15 NO 3 - . 15 N uptake by AMF hyphae accounted for 0.005-0.032% of total N uptake. (authors)

Results of surgical treatment of glomus tumor

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Kubilay Ersin Turkmen

2014-12-01

Conclusion: Glomus tumors are often diagnosed by their characteristic clinical symptoms; pain, tenderness and cold intolerance. Given the considerably delayed time to diagnosis, glomus tumors should be taken into consideration in the presence of severe finger tip pain of unknown origin. These patients are usually operated for other reasons because of difficulties in diagnosis. After the exploration of the tumors on nail bed, was repaired properly observed. [Hand Microsurg 2014; 3(3.000: 66-69

The potential of endomycorrhizal fungi in controlling tomato bacterial ...

African Journals Online (AJOL)

The impact of colonization by three mycorrhizal fungi on tomato bacterial wilt caused by Ralstonia solanaceraum was investigated. Three species of arbuscular mycorrhizal fungal (AMF) were tested (Glomus mosseae, Scutellospora sp. and Gigaspora margarita). Siginificant differences in tomato growth based on plant ...

root colonized by Glomus mosseae and Ralstonia solanacearum

African Journals Online (AJOL)

Yomi

2012-03-27

Mar 27, 2012 ... Ngakou et al., 2007), plant nutrition support (Mahmood and Rizvi, 2010), and salt stress (Shokri and Maadi,. 2009). Safir (1968) was the first to report the study on interaction of plant pathogenic fungi and species of AMF, followed by many reports confirming the reduction of disease severity as a result of ...

Glomus tumors in neurofibromatosis type 1: genetic, functional, and clinical evidence of a novel association.

Science.gov (United States)

Brems, Hilde; Park, Caroline; Maertens, Ophélia; Pemov, Alexander; Messiaen, Ludwine; Messia, Ludwine; Upadhyaya, Meena; Claes, Kathleen; Beert, Eline; Peeters, Kristel; Mautner, Victor; Sloan, Jennifer L; Yao, Lawrence; Lee, Chyi-Chia Richard; Sciot, Raf; De Smet, Luc; Legius, Eric; Stewart, Douglas R

2009-09-15

Neurofibromatosis type 1 (NF1) is a common disorder that arises secondary to mutations in the tumor suppressor gene NF1. Glomus tumors are small, benign but painful tumors that originate from the glomus body, a thermoregulatory shunt concentrated in the fingers and toes. We report 11 individuals with NF1 who harbored 20 glomus tumors of the fingers and 1 in the toe; 5 individuals had multiple glomus tumors. We hypothesized that biallelic inactivation of NF1 underlies the pathogenesis of these tumors. In 12 NF1-associated glomus tumors, we used cell culture and laser capture microdissection to isolate DNA. We also analyzed two sporadic (not NF1-associated) glomus tumors. Genetic analysis showed germ line and somatic NF1 mutations in seven tumors. RAS mitogen-activated protein kinase hyperactivation was observed in cultured NF1(-/-) glomus cells, reflecting a lack of inhibition of the pathway by functional neurofibromin, the protein product of NF1. No abnormalities in NF1 or RAS mitogen-activated protein kinase activation were found in sporadic glomus tumors. By comparative genomic hybridization, we observed amplification of the 3'-end of CRTAC1 and a deletion of the 5'-end of WASF1 in two NF1-associated glomus tumors. For the first time, we show that loss of neurofibromin function is crucial in the pathogenesis of glomus tumors in NF1. Glomus tumors of the fingers or toes should be considered as part of the tumor spectrum of NF1.

Studies of microbial development on mycorrhizosphere and ...

African Journals Online (AJOL)

Extracts from maize rhizosphere and mycorrhizosphere soil (both sterilized and unsterilized) were studied to assess the compatibility of the arbuscular mycorrhizae (AM) fungus (Glomus mosseae) with certain soil fungi, bacteria and rhizobacteria followed by assessment of the inhibitory effect of the identified rhizobacteria on ...

Radiotherapy in glomus jugulare and glomus tympanicum tumors

International Nuclear Information System (INIS)

Feyerabend, T.; Richter, E.; Kapp, B.; Bohndorf, W.; Ptok, M.

1989-01-01

Glomus jugulare tumors are difficult to manage therapeutically due to their localisation. Operation may be successful in small tumors but can be hazardous in larger lesions mainly because of bleeding and palsy of cranial nerves. In these cases there should be used radiation therapy under the condition that it is planned by use of computed tomography. Moreover reproducibility of radiation treatment set-up is vital. In this way tumor regression may be achieved. Four own illustrative cases are demonstrated. According to the stage of disease a modified treatment strategy is presented which integrates surgical procedures, angiographic embolisation and radiotherapy. (orig.) [de

Effect of arbuscular mycorrhizal fungi and pesticides on Cynara cardunculus growth

Directory of Open Access Journals (Sweden)

M. MARIN

2008-12-01

Full Text Available Wild cardoon (Cynara cardunculus L. is a promising crop for biomass production. A nursery trial was conducted to investigate the effectiveness of mycorrhizal inoculation on the biomass yield of wild cardoon seedlings and the effect of the pesticides fosetyl-Al, folpet and propamocarb, as fungicides, and isofenphos, phoxim and oxamyl, as insecticides, on cardoon plant growth and the mycorrhization. The arbuscular mycorrhizal (AM fungi inocula were: commercial inoculum with Glomus mosseae spores, and an inoculum of a Glomus sp. strain (AMF-i isolated locally. Mycorrhizal inoculation with either inoculum increased cardoon shoot biomass compared to non-inoculated control plants. The pesticide applications had a neutral or positive effect on cardoon seedling growth. However, the AM fungi colonisation did not decrease except for plants colonised by G. mosseae and treated with the insecticides isofenphos and oxamyl. Thus, the mycorrhiza can survive to pesticide concentrations employed in commercial nursery, and enhance cardoon plant productivity.

Arbuscular mycorrhizal fungi differentially affect the response to high zinc concentrations of two registered poplar clones

International Nuclear Information System (INIS)

Lingua, Guido; Franchin, Cinzia; Todeschini, Valeria; Castiglione, Stefano; Biondi, Stefania; Burlando, Bruno; Parravicini, Valerio; Torrigiani, Patrizia; Berta, Graziella

2008-01-01

The effects of a high concentration of zinc on two registered clones of poplar (Populus alba Villafranca and Populus nigra Jean Pourtet), inoculated or not with two arbuscular mycorrhizal fungi (Glomus mosseae or Glomus intraradices) before transplanting them into polluted soil, were investigated, with special regard to the extent of root colonization by the fungi, plant growth, metal accumulation in the different plant organs, and leaf polyamine concentration. Zinc accumulation was lower in Jean Pourtet than in Villafranca poplars, and it was mainly translocated to the leaves; the metal inhibited mycorrhizal colonization, compromised plant growth, and, in Villafranca, altered the putrescine profile in the leaves. Most of these effects were reversed or reduced in plants pre-inoculated with G. mosseae. Results indicate that poplars are suitable for phytoremediation purposes, confirming that mycorrhizal fungi can be useful for phytoremediation, and underscore the importance of appropriate combinations of plant genotypes and fungal symbionts. - Inoculation with arbuscular mycorrhizal fungi can improve poplar tolerance to heavy metals in phytoremediation programmes

Bacterial degradation of Aroclor 1242 in the mycorrhizosphere soils of zucchini (Cucurbita pepo L.) inoculated with arbuscular mycorrhizal fungi.

Science.gov (United States)

Qin, Hua; Brookes, Philip C; Xu, Jianming; Feng, Youzhi

2014-11-01

A greenhouse experiment was conducted to investigate the effects of zucchini (Cucurbita pepo L.), inoculated with the arbuscular mycorrhizal (AM) species Acaulospora laevis, Glomus caledonium, and Glomus mosseae, on the soil bacterial community responsible for Aroclor 1242 dissipation. The dissipation rates of Aroclor 1242 and soil bacteria abundance were much higher with the A. laevis and G. mosseae treatments compared to the non-mycorrhizal control. The biphenyl dioxygenase (bphA) and Rhodococcus-like 2,3-dihydroxybiphenyl dioxygenase (bphC) genes were more abundant in AM inoculated soils, suggesting that the bphA and Rhodococcus-like bphC pathways play an important role in Aroclor 1242 dissipation in the mycorrhizosphere. The soil bacterial communities were dominated by classes Betaproteobacteria and Actinobacteria, while the relative proportion of Actinobacteria was significantly (F=2.288, P<0.05) correlated with the PCB congener profile in bulk soil. Our results showed that AM fungi could enhance PCB dissipation by stimulating bph gene abundance and the growth of specific bacterial groups.

Effect of mycorrhizas application on plant growth and nutrient uptake in cucumber production under field conditions

Energy Technology Data Exchange (ETDEWEB)

Ortas, I.

2010-07-01

Mycorrhizas application in horticultural production in the Eastern Mediterranean region of Turkey has been studied under field conditions for several years. The effects of different arbuscular mycorrhizal fungi (AMF) have been evaluated under field conditions for cucumber production. The parameters measured were seedling survival, plant growth and yield, and root colonization. In 1998 and 1999, Glomus mosseae and Glomus etunicatum inoculated cucumber seedlings were treated with and without P (100 kg P2O5 ha-1) application. A second experiment was set up to evaluate the response of cucumber to the inoculation with a consortia of indigenous mycorrhizae, G. mosseae, G. etunicatum, Glomus clarum, Glomus caledonium and a mixture of these four species. Inoculated and control non inoculated cucumber seedlings were established under field conditions in 1998, 2001, 2002 and 2004. Seedling quality, seedling survival under field conditions and yield response to mycorrhiza were tested. Fruits were harvested periodically; at blossom, plant leaves and root samples were taken for nutrient content and mycorrhizal colonization analysis respectively. The field experiment results showed that mycorrhiza inoculation significantly increased cucumber seedling survival, fruit yield, P and Zn shoot concentrations. Indigenous mycorrhiza inoculum was successful in colonizing plant roots and resulted in better plant growth and yield. The relative effectiveness of each of the inocula tested was not consistent in the different experiments, although inoculated plants always grew better than control no inoculated. The most relevant result for growers was the increased survival of seedlings. (Author) 20 refs.

[Glomus tumour of the lung: a case report and literature review].

Science.gov (United States)

Baena-Del Valle, Javier Alonso; Murillo-Echeverri, Victoria Eugenia; Gaviria-Velásquez, Alejandro; Celis-Mejía, Diego Miguel; Matute-Turizo, Gustavo

2015-01-01

Glomus tumours are neoplasms arising from cells of the neuromyoarterial glomus bodies, which almost always occur in a subungual location. A lung location is extremely rare, with few cases reported in the literature. The case is presented of a 33 year-old male, with non-productive cough, dyspnoea at rest, intermittent fever, and mild pain in rib cage. A chest radiograph showed a consolidation in the left lung, and computed tomography revealed a lesion in the hilum that extended to the bronchus of the lingula obstructing, and causing post-obstructive pneumonia. A biopsy was obtained by rigid bronchoscopy biopsy, which showed a well circumscribed tumour constituted by intermediate-sized cells, and abundant cytoplasm that are arranged in a pattern surrounding numerous thin-walled blood vessels, with no pleomorphism, significant mitotic activity or necrosis. Immunohistochemistry revealed diffuse positivity with smooth muscle actin, vimentin, caldesmon; focal reactivity with desmin and CD117, CD34 highlights the vascular pattern. Ki67 proliferation rate was 1%. Synaptophysin, EMA and cytokeratin cocktail were negative, making the diagnosis of glomus tumour. Glomus tumours are rare neoplasms that usually appear in the dermis and subcutaneous tissue, where it is common to find glomus bodies. Occasionally glomus tumours can occur in extra-cutaneous sites such as the gastrointestinal tract, bone and respiratory system, with this case being a new case of rare lung location. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

A Rare Case of Malignant Glomus Tumor of the Esophagus

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Gurvinder Singh Bali

2013-01-01

Full Text Available Glomus tumors are rare neoplasms that usually occur on the hands in a subungual location, or sometimes in palms, wrists or soles of the feet. They are described as purple/pink tiny painful lesions with a triad of pain, local point tenderness, and cold hypersensitivity. They are almost always benign, but rare malignant variants have been reported. They have also been reported to be present at unusual locations, like the lung, stomach, or liver. Gastrointestinal glomus tumors are extremely rare tumors and very few cases have been reported in the literature. Most that have been reported were usually benign in nature. A rare esophageal glomangioma, mimicking a papilloma, was reported in 2006. We report a case of glomangiosarcoma (malignant glomus tumor in a 49-year-old female, who presented with symptoms of dysphagia including some spasm and hoarseness and subjective unintentional weight loss. On endoscopic exam, she was found to have a distal esophageal mass with malignant features. Radiologically, the mass had a size of about 8 cm on the CT scan without evidence of metastases. Pathology and immunostaining of the biopsy showed features resembling a malignant glomus tumor. She underwent an endoscopic and laparoscopic staging of the tumor along with ultrasound. Based on the laparoscopic findings, which were consistent with the preoperative diagnosis, she was scheduled for an esophagectomy. Histopathology and immunophenotypic features of the excised mass were consistent with a diagnosis of malignant glomus tumor.

Patch clamp study of mouse glomus cells using a whole carotid body.

Science.gov (United States)

Yamaguchi, Shigeki; Lande, Boris; Kitajima, Toshimitsu; Hori, Yuichi; Shirahata, Machiko

2004-03-04

Some electrophysiological characteristics of mouse glomus cells (DBA/2J strain) were investigated using an undissociated carotid body. The carotid body with major carotid arteries was placed in a recording chamber, and glomus cells were visualized with a water immersion lens combined with an infrared differential interference video camera. Patch clamp experiments revealed that voltage-gated outward current, but not inward current, was easily observed in glomus cells. Pharmacological experiments and the kinetics of the current suggest that outward current is via delayed rectifier, A type, and large conductance calcium-activated K channels. Furthermore, K current was reversibly attenuated by mild hypoxia. The results suggest electrophysiological similarities of glomus cells among the cat, the rat, and the DBA/2J mouse. The method appears useful for physiological experiments.

Dual inoculation with an Aarbuscular Mycorrhizal fungus and Rhizobium to facilitate the growth of alfalfa on coal mine substrates

Energy Technology Data Exchange (ETDEWEB)

Wu, F.Y.; Bi, Y.L.; Wong, M.H. [China University of Mining & Technology, Beijing (China)

2009-07-01

A pot experiment was conducted to investigate the effects of Glomus mosseae and Rhizobium on Medicago sativa grown on three types of coal mine substrates, namely a mixture of coal wastes and sands (CS), coal wastes and fly ash (CF), and fly ash (FA). Inoculation with Rhizobium alone did not result in any growth response but G. mosseae alone displayed a significant effect on plant growth. G. mosseae markedly increased the survival rate of M. sativa in CS substrate. In CF and FA substrates the respective oven dry weights of M. sativa inoculated with G. mosseae were 1.8 and 5.1 times higher than those without inoculation. Based on nitrogen (N), phosphorus (P) and potassium (K) uptake and legume growth, the results also show that dual inoculation in CS and CF substrates elicited a synergistic effect. This indicates that inoculation with arbuscular mycorrhizal (AM) fungi may be a promising approach for revegetation of coal mine substrates.

Radiotherapy in glomus jugulare and glomus tympanicum tumors. Zur Radiotherapie der Glomus-jugulare-et-tympanicum-Tumoren

Energy Technology Data Exchange (ETDEWEB)

Feyerabend, T; Richter, E; Kapp, B; Bohndorf, W [Wuerzburg Univ. (Germany, F.R.). Klinik und Poliklinik fuer Strahlentherapie; Ptok, M [Wuerzburg Univ. (Germany, F.R.). Klinik und Poliklinik fuer Hals-, Nasen- und Ohrenkranke

1989-09-01

Glomus jugulare tumors are difficult to manage therapeutically due to their localisation. Operation may be successful in small tumors but can be hazardous in larger lesions mainly because of bleeding and palsy of cranial nerves. In these cases there should be used radiation therapy under the condition that it is planned by use of computed tomography. Moreover reproducibility of radiation treatment set-up is vital. In this way tumor regression may be achieved. Four own illustrative cases are demonstrated. According to the stage of disease a modified treatment strategy is presented which integrates surgical procedures, angiographic embolisation and radiotherapy. (orig.).

Glomus tumors in neurofibromatosis type 1: genetic, functional and clinical evidence of a novel association

OpenAIRE

Brems, Hilde; Park, Caroline; Maertens, Ophélia; Pemov, Alexander; Messiaen, Ludwine; Upadhyaya, Meena; Claes, Kathleen; Beert, Eline; Peeters, Kristel; Mautner, Victor; Sloan, Jennifer L.; Yao, Lawrence; Lee, Chyi-Chia Richard; Sciot, Raf; Smet, Luc De

2009-01-01

Neurofibromatosis type 1 (NF1) is a common disorder that arises secondary to mutations in the tumor suppressor gene NF1. Glomus tumors are small, benign but painful tumors that originate from the glomus body, a thermoregulatory shunt concentrated in the fingers and toes. We report eleven individuals with NF1 who harbored 20 glomus tumors of the fingers and one in the toe; five individuals had multiple glomus tumors. We hypothesized that bi-allelic inactivation of NF1 underlies the pathogenesi...

Unusual imaging presentation of spinal glomus tumor: case report

OpenAIRE

Kuo, Chao-Hung; Huang, Wen-Cheng; Wu, Jau-Ching

2017-01-01

A glomangioma, also known as a glomus tumor, is a benign lesion and had rare occurrence of spine region. In this study, we presented a spinal glomus tumor with an unusual radiological presentation, which is different from osteolytic intraosseous patterns illustrated before. A 26-year-old male with compressive myelopathy caused by epidural intraspinal lesion over T11 level. Radiological presentation revealed reactive sclerotic change over the body and lamina was found on the same level in comp...

Functional diversity in arbuscular mycorrhizas: Exploitation of soil patches with different phosphate enrichment differs among fungal species

DEFF Research Database (Denmark)

Cavagnaro, T.R.; Smith, F.A.; Smith, S.E.

2005-01-01

. This was studied by growing symbioses of Linum usitatissimum and three AMF (Glomus intraradices, G. mosseae and Gigaspora margarita) in pots with two side-arms, which were accessible to hyphae, but not to roots. Soil in one side-arm was either unamended (P0) or enriched with P; simultaneous labelling of this soil...

Original Paper Le champignon arbusculaire Glomus aggregatum ...

African Journals Online (AJOL)

Le champignon arbusculaire Glomus aggregatum améliore la nutrition minérale de ... Salinity remains a major problem for soil fertility, especially in the Sahelian zone. However, many ...... environmental gradient in the Brazilian semiarid.

Carbon economy of sour orange in response to different Glomus spp.

Science.gov (United States)

Graham, J. H.; Drouillard, D. L.; Hodge, N. C.

1996-01-01

Vesicular-arbuscular mycorrhizal (M) fungal colonization, growth, and nonstructural carbohydrate status of sour orange (Citrus aurantium L.) seedlings were compared at low- and high-phosphorus (P) supply following inoculation with four Glomus isolates: G. intraradices (Gi, FL208), G. etunicatum (Ge, UT316), G. claroideum (Gc, SC186), and Glomus sp. (G329, FL906). Nonmycorrhizal (NM) seedlings served as controls. At low-P supply, increases in incidence of M colonization, vesicles and accumulation of fungal fatty acid 16:1omega(5)C in roots were most rapid for G329-inoculated seedlings, followed closely by Gi- and Gc-inoculated seedlings. Glomus etunicatum was a less aggressive colonizer and produced lower rates of fungal fatty acid accumulation in seedling roots than the other Glomus species. Nonmycorrhizal and Ge-inoculated seedlings had lower P status and growth rates than seedlings inoculated with Gi or G329. Glomus claroideum increased seedling P status, but growth rate was lower than for seedlings colonized by Gi or G329, suggesting higher belowground costs for Gc colonization. In P-sufficient roots colonized by Gi, Gc, or G329, starch and ketone sugar concentrations were lower than in P-deficient NM and Ge-inoculated plants. Under conditions of high-P supply where mycorrhizae provided no P benefit to the seedlings, colonization by Gc, Gi, and G329 was delayed and reduced compared to that at low-P supply; however, the relative colonization rates among Glomus spp. were similar. Colonization by Ge was not detected in roots until 64 days after inoculation. Compared to NM seedlings, growth rates of mycorrhizal seedlings were reduced by the three aggressive fungi but not by the less aggressive Ge. After 64 days, starch and ketone sugar concentrations were lower in fibrous roots colonized by Gc, Gi, and G329 than in NM roots, indicating greater utilization of nonstructural carbohydrates in roots colonized by the aggressive fungi. After 49 days, colonization by the

Application of arbuscular mycorrhizal fungi on the production of cut flower roses under commercial-like conditions

Energy Technology Data Exchange (ETDEWEB)

Garmendia, I.; Mangas, V. J.

2012-11-01

The objective of this work was to study the influence of two arbuscular mycorrhizal fungi (AMF) Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, and G. intraradices (Schenck and Smith) on cut flower yield of rose (Rosa hybrida L. cv. Grand Gala) under commercial-like greenhouse conditions. Flower production was positively influenced by G. mosseae inoculation. Both inocula tested caused low levels of mycorrhizal root colonization, with higher percentages in Rosa associated with G. mosseae. Significant improvement of plant biomass, leaf nutritional status or flower quality was not detected in inoculated plants probably due to the low symbiosis establishment. However, G. mosseae reduced by one month the time needed for 80% of the plants to flower and slightly increased number of cut flowers relative to non-mycorrhizal controls on the fourth, sixth and eighth months after transplanting. It is suggested that an altered carbohydrate metabolism could contribute to this positive effect. Low colonization of rose roots supports the idea that more effort is required to ensure successful application of AMF in ornamental production systems. (Author) 40 refs.

Effects of arbuscular mycorrhizal inoculation on plants growing on arsenic contaminated soil.

Science.gov (United States)

Jankong, P; Visoottiviseth, P

2008-07-01

Arbuscular mycorrhizal fungi (AMF) may play an important role in phytoremediation of As-contaminated soil. In this study the effects of AMF (Glomus mosseae, Glomus intraradices and Glomus etunicatum) on biomass production and arsenic accumulation in Pityrogramma calomelanos, Tagetes erecta and Melastoma malabathricum were investigated. Soil (243 +/- 13 microg As g(-1)) collected from Ron Phibun District, an As-contaminated area in Thailand, was used in a greenhouse experiment. The results showed different effects of AMF on phytoremediation of As-contaminated soil by different plant species. For P. calomelanos and T. erecta, AMF reduced only arsenic accumulation in plants but had no significant effect on plant growth. In contrast, AMF improved growth and arsenic accumulation in M. malabathricum. These findings show the importance of understanding different interactions between AMF and their host plants for enhancing phytoremediation of As-contaminated soils.

Glomus jugulare tumor with intra- and extracranial extension

International Nuclear Information System (INIS)

Morisako, Toshitaka; Goya, Tomokazu; Wakisaka, Shinichiro; Kinoshita, Kazuo

1987-01-01

A case of glomus jugulare tumor with intra- and extracranial extension is described. The patient was a 63-year-old woman who complained of gait and memory disturbances. On admission neurological examination revealed recent memory disturbance, left deafness, left XI, XIIth cranial nerve palsies, and slight ataxic gait. Roentgenogram of the skull showed an enlarged left jugular foramen with bone erosion. Plain X-ray computerized tomography scan (X-CT) indicated obstructive hydrocephalus and X-CT with contrast enhancement revealed a mass lesion in the left posterior cranial fossa extending through enlarged left jugular foramen to the extracranial space toward the level of C 2 . Cerebral angiography demonstrated a large mass with blood supply from branches of left external carotid and vertebral arteries. The tumor stain was not remarkable. Left internal jugular vein was completely obstructed at the level of the second cervical vertebral body. Magnetic resonance imaging (MRI) clearly showed the tumor extending from the anterolateral portion to the second cervical vertebral body through the enlarged jugular foramen to the posterior cranial fossa. Brain stem and cerebellar hemisphere which were markedly compressed by the mass were clearly visualized. At first a ventriculo-peritoneal shunt was made and four weeks later subtotal removal of the tumor was undertaken. Histopathology of tumor specimen showed typical glomus jugulare tumor. MRI was considered to be very useful for the diagnosis and treatment of the glomus jugulare tumor with intra- and extracranial extension. (author)

Influence of two glomus species on the fertilizer efficiency of sokoto ...

African Journals Online (AJOL)

The treatments consisted of sole inoculations of G. mosseae and G. deserticola and their combinations with phosphate rock (PR), sole application of PR, SSP and a no-inoculation, no-fertilizer control. Results obtained revealed that the percent colonization rate of arbuscular mycorrhiza fungi (AMF) was significantly higher in ...

The Effect of Irrigation Intervals and Arbuscular Mycorrhizal Fungi on Chlorophyll Index, Yield and Yield Components of Grain Sorghum

Directory of Open Access Journals (Sweden)

J. Hamzei

2014-08-01

Full Text Available This experiment was carried out to study the effect of irrigation intervals and arbuscular mycorrhizal fungi on chlorophyll index, yield and yield components of grain sorghum. A factorial experiment was done based on randomized complete block design (RCBD with three replications at the Agriculture Research Station faculty of Agriculture, Bu- Ali Sina University in growing season of 2011. Irrigation intervals (7, 14 and 21 days with three levels of seed inoculation (control without inoculation, inoculation with Glomus mossea and inoculation with G. intraradices were the experimental treatments. Results indicated that the effect of irrigation intervals and mycorrhizal fungi were significant for traits of chlorophyll index, percentage of root symbiosis (PRS, number of grain per panicle, 1000 seed weight, grain yield and harvest index (HI. Maximum value for each trait was observed at G. mossea treatment. G. mossea treatment in comparison with G. intraradices and control treatment can increase the grain yield of sorghum up to 6.80 and 23.10%, respectively. Also, with increasing irrigation interval from 7 to 21 days, PRS increased up to 27.9%. Maximum value for grain yield (755 g m-2 was achieved at irrigation every 14 days and application of G. mossea treatment. But, there was no significant difference between irrigation sorghum plants every 14 days and application of G. mossea and irrigation every 7 days and application of either G. mossea or G. intraradices. In general, irrigation of sorghum plants every 14 days and supplying of G. mossea can produce the highest grain yield, while decreasing water consumption for sorghum production.

Influence of arbuscular mycorrhizas on the growth rate of mist-propagated olive plantlets

OpenAIRE

Porras Piedra, A.; Soriano Martín, M.L.; Porras Soriano, A.; Fernández Izquierdo, G.

2005-01-01

The aim of this work was to determine the influence of early inoculation of semi-woody olive cuttings (cv. Cornicabra), cultivated under mist propagation conditions, with arbuscular mycorrhizal fungi. A strongly positive response was seen to root inoculation with the three fungal species tested —Glomus mosseae, G. intraradices and G. claroideum— both in nursery phase plantlets, and in older plants grown in 5 L pots.

1840-IJBCS-Article-Sarr Bathie

African Journals Online (AJOL)

hp

des minitubercules. Le calibre des minitubercules présente une variabilité de réponse selon la variété de pomme de terre et le type d'insecticide. Ce travail a permis ... Glomus mosseae avec l'application des insecticides au sol chez les variétés Aïda et Atlas de la pomme de terre. .... tubes de verres (22x150 mm) contenant.

Flavonoids released naturally from alfalfa promote development of symbiotic glomus spores in vitro.

Science.gov (United States)

Tsai, S M; Phillips, D A

1991-05-01

Because flavonoids from legumes induce transcription of nodulation genes in symbiotic rhizobial bacteria, it is reasonable to test whether these compounds alter the development of vesicular-arbuscular mycorrhizal (VAM) fungi that infect those plants. Quercetin-3-O-galactoside, the dominant flavonoid released naturally from alfalfa (Medicago sativa L.) seeds, promoted spore germination of Glomus etunicatum and Glomus macrocarpum in vitro. Quercetin produced the maximum increases in spore germination, hyphal elongation, and hyphal branching in G. etunicatum at 1 to 2.5 muM concentrations. Two flavonoids exuded from alfalfa roots, 4',7-dihydroxyflavone and 4',7-dihydroxyflavanone, also enhanced spore germination of this fungal species. Formononetin, an isoflavone that is released from stressed alfalfa roots, inhibited germination of both Glomus species. These in vitro results suggest that plant flavonoids may facilitate or regulate the development of VAM symbioses and offer new hope for developing pure, plant-free cultures of VAM fungi.

Effects of mycorrhiza on growth and essential oil production in selected aromatic plants

Directory of Open Access Journals (Sweden)

Waed Tarraf

2015-09-01

Full Text Available Arbuscular mycorrhizal (AM symbiosis is widely investigated in aromatic herbs. Several studies have shown different effects on secondary metabolites, biomass production, as well as oil quantitative and qualitative aspects. The seeking to increase the yield of plants and their oils is an interesting topic in the world of medicinal and aromatic plant production. In tune with that, this study evaluated the effectiveness of two mycorrhiza fungi, Funneliformis mosseae (syn. Glomus mosseae and Septoglomus viscosum (syn. Glomus viscosum, on three species from Lamiaceae family: Salvia officinalis L., Origanum vulgare L., and Thymus vulgaris L. besides untreated control. It was found that the effect of symbiosis on growth was more favourable with S. viscosum than other AM fungus. The S. viscosum inoculation raised the yield of essential oil in oregano. Analysis of gas chromatography/mass spectrometry showed that manool obtained the highest abundance in leaf essential oil of inoculated sage; thymol was the major component whatever the treatment in thyme and lower relative content of carvacrol was reported with arbuscular mycorrhizal fungi inoculation in oregano. The results suggest the mycorrhizal inoculation as a promising technology in sustainable agricultural system to improve the plant productivity performance. Specific inocula are strategic to enhance the chemical profile of essential oils.

Dual Inoculation with Mycorrhizal and Saprotrophic Fungi Applicable in Sustainable Cultivation Improves the Yield and Nutritive Value of Onion

OpenAIRE

Albrechtova, Jana; Latr, Ales; Nedorost, Ludovit; Pokluda, Robert; Posta, Katalin; Vosatka, Miroslav

2012-01-01

The aim of this paper was to test the use of dual microbial inoculation with mycorrhizal and saprotrophic fungi in onion cultivation to enhance yield while maintaining or improving the nutritional quality of onion bulbs. Treatments were two-factorial: (1) arbuscular mycorrhizal fungi (AMF): the mix corresponding to fungal part of commercial product Symbivit (Glomus etunicatum, G. microaggregatum, G. intraradices, G. claroideum, G. mosseae, and G. geosporum) (M1) or the single-fungus inoculum ...

Resistance to high level of Cu (Copper) by arbuscular mycorrhizal, saprobe Fungi and Eucalyptus globules

International Nuclear Information System (INIS)

Arriagada, C.; Pereira, G.; Machuca, A.; Alvear, M.; Martin, J.; Ocampo, J.

2009-01-01

The effects of saprobe and arbuscular mycorrhizal (AM) fungi on growth, chorophyll, root length colonization and succinate dehydrogenase (SDH) activity was measured in Eucalyptus globulus Labill., plants growing in soil with high level of Cu were investigated. The application of Cu inhibited the development of mycelia of the saprobe fungi Fusarium concolor and Trichoderma koningii and the hyphal length of the arbuscular mycorrhizal fungi (AM) Glomus mosseae and G. deserticola in vitro. (Author)

Subungual onychomycosis due to Aspergillus niger mimicking a glomus tumor: A case report.

Science.gov (United States)

Matsuyama, Yumi; Nakamura, Tomoki; Hagi, Tomohito; Asanuma, Kunihiro; Sudo, Akihiro

2017-12-01

Onychomycosis is a common nail infection caused by dermatophytes, while non-dermatophytes including Aspergillus spp. are causes of nail onychomycosis. Aspergillus niger is not common as a cause of nail onychomycosis. In the current study we present a 60-year-old woman with subungual onychomycosis due to Aspergillus niger mimicking a glomus tumor. Physical examination revealed right thumb had a black color of nail bed. Localized tenderness and severe pain were observed. However, the cold sensitivity test, Loves pin test and Hildreths test were negative. On radiograph, bone erosion was found in a part of distal phalanx at the right thumb. Magnetic resonance imaging identified a mass at the subungual space, which exhibited low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The differential diagnosis included glomus tumor and infection. The histological findings demonstrated dichotomous septate hyphae. The culture was positive for Aspergillus niger . The results suggested that when physical examination is not typical for a glomus tumor, other diseases may be considered. Additionally, frozen section diagnosis may be useful.

Effect of Three Species of Mycorrhiza Inoculation on Yield and Some Physiological properties of Two Potato Cultivars under Drought Stress in Controlled Conditions

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S. Khaninejad

2017-03-01

Full Text Available Introduction In recent years, rainfall deficiency was an increasing problem in most countries; which limited the production of agricultural crops. Among abiotic stresses the plants encountered, drought stress is considered as the most important limiting factor in plants growth and reproduction in natural and agricultural systems through most parts of the world; while drought stress causes 45% increase in the crops among various stress making factors (biotic and abiotic. A suitable procedure for controlling drought stress in agriculture is making the symbiotic relation between plants and mycorrhizal fungi. Mycorrhizal fungi decrease the plant ability in absorbing nutrients, ion balance, keeping enzyme activity, increasing chlorophyll density and root-soil connection; they decline the hazards caused by stress and decrease the plant tolerance to biotic and abiotic stresses. Potato is one of the most valuable sources to provide human food in the developing countries and is one of the most productive crops, while its production is twofold to rice and wheat. Producing more than 5 million tones potato makes this crop as the first utilizable nutrient after wheat, in this country. Potato is sensitive to soil humidity caused by limited and low-deep root system. Materials and Methods Thus, an investigation was conducted to examine the effect of three of mycorrhizal fungi (Glomus mosseae, Glomus intraradices and Glomus fasciculatum on two potato cultivars (Agria and Fontana under drought stress and control conditions, in factorial experiment based on complete randomize block with three repetitions in research greenhouse of Ferdowsi University in 2012. In control treatment, irrigating was done when field capacity got 80% and it was conducted to 100% field capacity. Stress treatment was done when the field capacity got 60% and continued to 80% field capacity. Fungus treatment was done with a 100g mixture of inoculum including mycorrhizal root sections of corn

Performance of Glomus clarum and Tithonia diversifolia compost in ...

African Journals Online (AJOL)

Screen house experiments were conducted at the Institute of Agricultural Research and Training, Ibadan, on a sandy loam soil in two years, to assess the effect of arbuscular mycorrhizal fungus (Glomus clarum) and compost (sunflower) on the growth and yield of tomato plants. The experimental design was laid out in a ...

Underground resource allocation between individual networks of mycorrhizal fungi

DEFF Research Database (Denmark)

Mikkelsen, Bolette Lind; Rosendahl, Søren; Jakobsen, Iver

2008-01-01

* Fusions between individual mycelia of arbuscular mycorrhizal (AM) fungi have been observed in two-dimensional systems but never in soil systems. Here, phosphorus ((32)P) labelling was used to demonstrate nutrient transfer between individual mycelia and to investigate the possible role...... of G. mosseae overlapped. The transfer probably occurred via anastomoses between the mycelia as no transfer of (32)P was detected between the mycelia of different fungi at the second harvest. * The indicated ability of AM fungal mycelia to anastomose in soil has implications for the formation of large...... of anastomosis. * Trifolium subterraneum colonized by Glomus mosseae were grown in root-retaining mesh bags, which were placed 20 cm apart. The mycelium of one plant, the donor, had access to (32)P-labelled soil placed adjacent to the mesh bag. Transfer of (32)P from the donor mycelium to the receiver plant...

The plant growth promoting substance, lumichrome, mimics starch and ethylene-associated symbiotic responses in lotus and tomato roots

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Liezel eGouws

2012-06-01

Full Text Available Symbiosis involves responses that maintain the plant host and symbiotic partner’s genetic program; yet these cues are far from elucidated. Here we describe the effects of lumichrome, a flavin identified from Rhizobium spp., applied to lotus (Lotus japonicus and tomato (Solanum lycopersicum. Combined transcriptional and metabolite analyses suggest that both species shared common pathways that were altered in response to this application under replete, sterile conditions. These included genes involved in symbiosis, as well as transcriptional and metabolic responses related to enhanced starch accumulation and altered ethylene metabolism. Lumichrome priming also resulted in altered colonization with either Mesorhizobium loti (for lotus or Glomus intraradices/Glomus mossea (for tomato. It enhanced nodule number but not nodule formation in lotus; while leading to enhanced hyphae initiation and delayed arbuscule maturation in tomato.

Mycorrhizal Inoculum Production Technique for Land Rehabilitation

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Yadi Setiadi

2011-01-01

Full Text Available Spora cendawan mikoriza arbuskula (CMA telah dikoleksi dan diisolasi dari berbagai jenis tanah masam berfikasi P-tinggi di Indonesia. Lima isolate CMA lokal telah berhasil diperoleh dari spora tunggal dengan teknik “test tube culture” dan dikembangkan-biakan dengan sistem “open pot culture”. Kelima isolate tersebut adalah Acaulospora delicata (EJ-01. Acaulospora tuberculata (INDO-2, Glomus manihotis (INDO-1, Glomus mosseae (PAL-03 dan Entrophospora colombiana (LAM-36. Kelima biakan isolate CMA tersebut, dipelihara dengan tanaman inang Kudzu pada media zeolit yang diperkaya nutrisi. Dengan mempelajari berbagai tipe media, ukuran partikel, pH dan komposisi nutrisi, isolate CMA terpilih telah berhasil dapat diperbanyak dalam skala industri dengan menggunakan inang sorghum. Dengan tehnik pra-inokulasi di persemaiaan maka penggunaan mikoriza dalam skala besar di bidang kehutanan dapat direalisasikan.

Effects of metal lead on growth and mycorrhizae of an invasive plant species (Solidago canadensis L.).

Science.gov (United States)

Yang, Ruyi; Yu, Guodong; Tang, Jianjun; Chen, Xin

2008-01-01

It is less known whether and how soil metal lead (Pb) impacts the invasion of exotic plants. A greenhouse experiment was conducted to estimate the effects of lead on the growth and mycorrhizae of an invasive species (Solidago canadensis L.) in a microcosm system. Each microcosm unit was separated into HOST and TEST compartments by a replaceable mesh screen that allowed arbuscular mycorrhizal (AM) fungal hyphae rather than plant roots to grow into the TEST compartments. Three Pb levels (control, 300, and 600 mg/kg soil) were used in this study to simulate ambient soil and two pollution sites where S. canadensis grows. Mycorrhizal inoculum comprised five indigenous arbuscular mycorrhizal fungal species (Glomus mosseae, Glomus versiform, Glomus diaphanum, Glomus geosporum, and Glomus etunicatum). The 15N isotope tracer was used to quantify the mycorrhizally mediated nitrogen acquisition of plants. The results showed that S. canadensis was highly dependent on mycorrhizae. The Pb additions significantly decreased biomass and arbuscular mycorrhizal colonization (root length colonized, RLC%) but did not affect spore numbers, N (including total N and 15N) and P uptake. The facilitating efficiency of mycorrhizae on nutrient acquisition was promoted by Pb treatments. The Pb was mostly sequestered in belowground of plant (root and rhizome). The results suggest that the high efficiency of mycorrhizae on nutrient uptake might give S. canadensis a great advantage over native species in Pb polluted soils.

EFECTIVIDAD DE CEPAS DE HMA EN EL CULTIVO DE LA YUCA (Manihot esculenta Crantz) EN DOS TIPOS DE SUELOS

OpenAIRE

José P. João; Alberto Espinosa Cuellar; Luís Ruiz Martínez; Jaime Simó González; Ramón Rivera Espinosa

2016-01-01

Con el objetivo de evaluar la efectividad de la inoculación de cepas de hongos micorrízicos arbusculares (HMA) en clones comerciales de yuca (Manihot esculenta Crantz) y su dependencia con el tipo de suelo, se comparó la efectividad de tres cepas de HMA, Glomus cubense, Rizophagus intraradices y Funneliformis mosseae, tanto en suelo Pardo Mullido Carbonatado como en Ferralítico Rojo Lixiviado. En el primer suelo, se utilizaron seis clones comerciales en un diseño de bloq...

Growth Response of Two Phaseolus mungo L. Cultivars Induced by Arbuscular Mycorrhizal Fungi and Trichoderma viride

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Navnita Sharma

2016-01-01

Full Text Available The present investigation aimed to quantify the difference in response of two Phaseolus mungo L. cultivars (i.e., UH-1 and IPU-94-1 to Glomus mosseae (G, that is, Funneliformis mosseae, Acaulospora laevis (A, and Trichoderma viride (T, in different combinations or alone. All the treatments were inoculated with Bradyrhizobium japonicum to ensure nodulation as soil used in the experiment was sterilized. After 120 days of inoculation, plants were analyzed for chlorophyll content, nodulation, mycorrhization, leaf area, and protein content. Results indicate variation in growth response of two cultivars with different treatments. Triple inoculation of plants with G + A + T proved to be the best treatment for growth followed by G + T in both cultivars. Our work allowed the selection of P. mungo L. cultivar UH-1 as highly mycorrhizal responsive as compared to IPU-94-1 and G. mosseae to be an efficient bioinoculant as compared to A. laevis for growth enhancement of P. mungo. Further characterization of P. mungo genotypes will enhance our knowledge of physiological and genetic mechanism behind increase in plant growth and yield due to AM symbiosis.

Synchronous subungual glomus tumors in the same finger Tumores glômicos subungueais sincrônicos no mesmo dedo

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Nilton Di Chiacchio

2012-06-01

Full Text Available The glomus tumor is an uncommon benign neoplasm of glomus cells. In the majority of the cases it is presented as a solitary painful papule in the subungual region. We report a rare case of a patient with two individual synchronous glomus tumors under the nail bed of the same finger.O tumor glômico é uma neoplasia benigna de células glômicas. Na maioria dos casos se apresenta como uma pápula solitária dolorosa na região subungueal. Relatamos o caso raro de um paciente com dois tumores glômicos sincrônicos sob o leito ungueal do mesmo dedo.

The safety and efficacy of gamma knife surgery in management of glomus jugulare tumor

Science.gov (United States)

2010-01-01

Background Glomus jugulare is a slowly growing, locally destructive tumor located in the skull base with difficult surgical access. The operative approach is, complicated by the fact that lesions may be both intra and extradural with engulfment of critical neurovascular structures. The tumor is frequently highly vascular, thus tumor resection entails a great deal of morbidity and not infrequent mortality. At timeslarge residual tumors are left behind. To decrease the morbidity associated with surgical resection of glomus jugulare, gamma knife surgery (GKS) was performed as an alternative in 13 patients to evaluate its safety and efficacy. Methods A retrospective review of 13 residual or unresectable glomus jagulare treated with GKS between 2004 and 2008.. Of these, 11 patients underwent GKS as the primary management and one case each was treated for postoperative residual disease and postembolization. The radiosurgical dose to the tumor margin ranged between 12-15 Gy. Results Post- gamma knife surgery and during the follow-up period twelve patients demonstrated neurological stability while clinical improvement was achieved in 5 patients. One case developed transient partial 7th nerve palsy that responded to medical treatment. In all patients radiographic MRI follow-up was obtained, the tumor size decreased in two cases and remained stable (local tumor control) in eleven patients. Conclusions Gamma knife surgery provids tumor control with a lowering of risk of developing a new cranial nerve injury in early follow-up period. This procedure can be safely used as a primary management tool in patients with glomus jugulare tumors, or in patients with recurrent tumors in this location. If long-term results with GKS are equally effective it will emerge as a good alternative to surgical resection. PMID:20819207

A metastatic glomus jugulare tumor. A temporal bone report

International Nuclear Information System (INIS)

El Fiky, F.M.; Paparella, M.M.

1984-01-01

The clinicopathologic findings in the temporal bone of a patient with a highly malignant metastasizing glomus jugulare tumor are reported. The patient exhibited all the symptoms of primary malignant tumors of the ear, including facial paralysis, otorrhea, pain, hearing loss, tinnitus, dizziness, and vertigo. He was treated with cobalt irradiation followed by radium implant in the ear canal for a residual tumor; then a left-sided radical mastoidectomy was performed

Glucose sensing by carotid body glomus cells: potential implications in disease

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Lin eGao

2014-10-01

Full Text Available The carotid body (CB is a key chemoreceptor organ in which glomus cells sense changes in blood O2, CO2, and pH levels. CB glomus cells have also been found to detect hypoglycemia in both non-primate mammals and humans. O2 and low-glucose responses share a common final pathway involving membrane depolarization, extracellular calcium influx, increase in cytosolic calcium concentration, and neurotransmitter secretion, which stimulates afferent sensory fibers to evoke sympathoadrenal activation. On the other hand, hypoxia and low glucose induce separate signal transduction pathways. Unlike O2 sensing, the response of the CB to low glucose is not altered by rotenone, with the low glucose-activated background cationic current unaffected by hypoxia. Responses of the CB to hypoglycemia and hypoxia can be potentiated by each other. The counter-regulatory response to hypoglycemia by the CB is essential for the brain, an organ that is particularly sensitive to low glucose. CB glucose sensing could be altered in diabetic patients, particularly those under insulin treatment, as well as in other medical conditions such as sleep apnea or obstructive pulmonary diseases, where chronic hypoxemia presents with plastic modifications in CB structure and function. The current review will focus on the following main aspects: 1 the CB as a low glucose sensor in both in vitro and in vivo models; 2 molecular and ionic mechanisms of low glucose sensing by glomus cells, 3 the interplay between low glucose and O2 sensing in CB, and 4 the role of CB low glucose sensing in the pathophysiology of cardiorespiratory and metabolic diseases, and how this may serve as a potential therapeutic target.

Plant growth and metal distribution in tissues of Prosopis juliflora-velutina grown on chromium contaminated soil in the presence of Glomus deserticola

OpenAIRE

Arias, Jack A.; Peralta-Videa, Jose R.; Ellzey, Joanne T.; Viveros, Marian N.; Ren, Minghua; Mokgalaka-Matlala, Ntebogeng S.; Castillo-Michel, Hiram; Gardea-Torresdey, Jorge L.

2010-01-01

Arbuscular mycorrhizal fungi have been known to increase metal uptake in plants. In this study, mesquite (Prosopis juliflora-velutina) inoculated with Glomus deserticola or amended with EDTA were grown for 30 days in soil containing Cr(III) or Cr(VI) at 0, 40, 80, and 160 mg kg−1. Total amylase activity (TAA) was monitored as a stress indicator. Element concentrations and distribution in tissue were determined using ICP-OES, electron scanning microprobe, and TEM. Inoculated Cr(VI) treated pla...

Metabolic activity of Glomus intraradices in Arum- and Paris-type arbuscular mycorrhizal colonization

NARCIS (Netherlands)

van Aarle, IM; Cavagnaro, TR; Smith, SE; Dickson, S

Colonization of two plant species by Glomus intraradices was studied to investigate the two morphological types (Arum and Paris), their symbiotic interfaces and metabolic activities. Root pieces and sections were stained to observe the colonization and metabolic activity of all mycorrhizal

Evaluation of Two Mycorrhiza Species and Nitroxin on Yield and Yield Components of Garlic (Allium sativum L. in an Ecological Agroecosystem

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P Rezvani Moghaddam

2016-02-01

biofertilizers on different crops, information on the effects of these factors for many medicinal plants such as garlic is scarce; therefore, in this study the effects of mycorrhiza and biofertilizers on quantitative characteristics of garlic in a low input cropping system were studied. Materials and Methods In order to study the effects of two mycorrhiza species and nitroxin on yield and yield components of garlic (Allium sativum L., an experiment was conducted in a factorial arrangement based on a randomized completed block design with three replications in the growing seasons of 2010 at the experimental farm of College of Agriculture, Ferdowsi University of Mashhad, Iran. The experimental factors were all combination of two mycorrhiza species (Glomus mosseae, Glomus intraradices and control and also inoculation with and without nitroxin (include Azotobacter sp. and Azospirillum sp. as a biofertilizer. Results and Discussion The results showed that both two mycorrhiza species had superior effects on most of the study traits compared with control. Bulb weight per plant was significantly affected by mycorrhiza species. Glomus mosseae، and Glomus intraradices increased bulb weight per plant by 48 and 29 percent compared with control, respectively. Nitroxin had a significant effect on length and diameter of bulbs. Length and diameter of bulbs were increased by 13 and 8 percent using nitroxin compared with control, respectively. Interactive effects of mycorrhiza and nitroxin on all study traits also were significant. Interactive effects of study treatments showed that Glomus mosseae had better effect on most of study traits at with and without nitroxin treatments. On the other hand, nitroxin had synergistic effect on mycorrhiza treatments compared when these treatments were used without nitroxin. Highest (4306 kg ha-1 and lowest (1665 kg ha-1 economic yield (bulb yield were obtained from Glomus mosseae + Nitroxin and control (without mycorhiza and nitroxin, respectively. In

Gastric Glomus Tumor: A Rare Cause of Upper Gastrointestinal Bleeding

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Yoshinori Handa

2015-01-01

Full Text Available A 24-year-old woman was referred to our department because of melena. These symptoms combined with severe anemia prompted us to perform an emergency upper endoscopy, which showed bleeding from an ulcerated 30 mm submucosal tumor in the gastric antrum. A computed tomography scan revealed a homogeneously enhanced mass, and endoscopic ultrasonography identified a well-demarcated mass in the third and fourth layers of the gastric wall. Because analysis of the possible medical causes remained inconclusive and the risk of rebleeding, laparoscopy-assisted gastric wedge resection was performed after administration of 10 units of red cell concentrate. Histological and immunohistological analysis revealed the tumor to be a gastric glomus tumor. Gastric submucosal tumors remain challenging to diagnose preoperatively as they show a variety of radiologic and clinicopathologic features and are associated with the risk of bleeding upon biopsy, as is indicated in the guidelines for gastric submucosal tumors. Gastric glomus tumors characteristically present with exsanguinating gastrointestinal hemorrhaging that often requires blood transfusion. Additionally, gastric submucosal tumors typically occur in elderly patients; however, this case involved a young patient who was 24 years old. Here, we describe this case in order to identify features that may aid in early differentiation of gastric submucosal tumors.

Leksell Gamma Knife radiosurgery of the jugulotympanic glomus tumor: long-term results.

Science.gov (United States)

Liscak, Roman; Urgosik, Dusan; Chytka, Tomas; Simonova, Gabriela; Novotny, Josef; Vymazal, Josef; Guseynova, Khumar; Vladyka, Vilibald

2014-12-01

Glomus tumors usually display indolent behavior, and the effectiveness of radiation in stopping their growth can be assessed after long-term follow-up. Currently only midterm results of radiosurgery are available, so the authors included patients treated by Gamma Knife at least 10 years ago in this study to obtain a perspective of long-term results. During the period from 1992 to 2003, the Gamma Knife was used to treat 46 patients with glomus tumors. The age of the patients ranged from 21 to 79 years (median 56 years). Gamma Knife radiosurgery was the primary treatment in 17 patients (37%). Open surgery preceded radiosurgery in 46% of cases, embolization in 17%, and fractionated radiotherapy in 4%. The volume of the tumor ranged from 0.2 to 24.3 cm(3) (median 3.6 cm(3)). The minimal dose to the tumor margin ranged between 10 and 30 Gy (median 20 Gy). One patient was lost for follow-up after radiosurgery. Clinical follow-up was available in 45 patients and 44 patients were followed with MRI in a follow-up period that ranged from 12 to 217 months (median 118 months). Neurological deficits improved in 19 (42%) of 45 patients and deteriorated in 2 patients (4%). Tumor size decreased in 34 (77%) of 44 patients with imaging follow-up, while an increase in volume was observed in 1 patient (2%) 182 months after radiosurgery and Gamma Knife treatment was repeated. One patient underwent another Gamma Knife treatment for secondary induced meningioma close to the glomus tumor 98 months after initial radiosurgical treatment. Seven patients died 22-96 months after radiosurgery (median 48 months), all for unrelated reasons. Radiosurgery has proved to be a safe treatment with a low morbidity rate and a reliable long-term antiproliferative effect.

Arbuscular mycorrhizal fungal hyphae contribute to the uptake of polycyclic aromatic hydrocarbons by plant roots.

Science.gov (United States)

Gao, Yanzheng; Cheng, Zhaoxia; Ling, Wanting; Huang, Jing

2010-09-01

The arbuscular mycorrhizal (AM) hyphae-mediated uptake of polycyclic aromatic hydrocarbons (PAHs) by the roots of ryegrass (Lolium multiflorum Lam.) was investigated using three-compartment systems. Glomus mosseae and Glomus etunicatum were chosen, and fluorene and phenanthrene were used as representative PAHs. When roots were grown in un-spiked soils, AM hyphae extended into PAH-spiked soil and clearly absorbed and transported PAHs to roots, resulting in high concentrations of fluorene and phenanthrene in roots. This was further confirmed by the batch equilibration experiment, which revealed that the partition coefficients (K(d)) of tested PAHs by mycorrhizal hyphae were 270-356% greater than those by roots, suggesting the great potential of hyphae to absorb PAHs. Because of fluorene's lower molecular weight and higher water solubility, its translocation by hyphae was greater than that of phenanthrene. These results provide new perspectives on the AM hyphae-mediated uptake by plants of organic contaminants from soil. Copyright 2010 Elsevier Ltd. All rights reserved.

Clonal diversity and population genetic structure of arbuscular mycorrhizal fungi (Glomus spp.) studied by multilocus genotyping of single spores

DEFF Research Database (Denmark)

Holtgrewe-Stukenbrock, Eva; Rosendahl, Søren

2005-01-01

A nested multiplex PCR (polymerase chain reaction) approach was used for multilocus genotyping of arbuscular mycorrhizal fungal populations. This method allowed us to amplify multiple loci from Glomus single spores in a single PCR amplification. Variable introns in the two protein coding genes Gm......FOX2 and GmTOR2 were applied as codominant genetic markers together with the LSU rDNA.   Genetic structure of Glomus spp. populations from an organically and a conventionally cultured field were compared by hierarchical sampling of spores from four plots in each field. Multilocus genotypes were...

Subungual Hypervascular Soft Tissue Chondroma Mimicking a Glomus Tumor: A Case Report

International Nuclear Information System (INIS)

Park, Jong Chun; Lee, Young Hwan; Jung, Kyung Jae

2009-01-01

Soft tissue chondroma, or extraskeletal chondroma, is a relatively rare, benign cartilaginous tumor that occurs most frequently in the hands and feet - a subungual location is quite rare. The authors describe a subungual soft tissue chondroma in a 25-year-old man that was visualized as a hypervascular mass on color Doppler ultrasonography and initially misdiagnosed as a glomus tumor

Subungual Hypervascular Soft Tissue Chondroma Mimicking a Glomus Tumor: A Case Report

Energy Technology Data Exchange (ETDEWEB)

Park, Jong Chun; Lee, Young Hwan; Jung, Kyung Jae [Catholic University of Daegu, School of Medicine, Daegu (Korea, Republic of)

2009-09-15

Soft tissue chondroma, or extraskeletal chondroma, is a relatively rare, benign cartilaginous tumor that occurs most frequently in the hands and feet - a subungual location is quite rare. The authors describe a subungual soft tissue chondroma in a 25-year-old man that was visualized as a hypervascular mass on color Doppler ultrasonography and initially misdiagnosed as a glomus tumor

The Effect of Vesicular Arbuscular Mycorrhizal (VAM on Yield and Yield Components of Three Sorghum (Sorghum bicolor Cultivars

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A. Mehraban

2012-10-01

Full Text Available To evaluate the influence of vesicular arbuscular mycorrhizal (VAM on yield and yield components of three sorghum cultivars, a factorial experiment based randomized complete block design with four replications was carried out in 2007, at the Agricultural Research Center of Zahak, Iran. The treatments were different mycorrhiza species in three levels: without mycorrhiza (M1, Glomus etanicatum (M2 and G. mosseae(M3 and three cultivars of sorghum: local cultivars (C1, KGS25 (C2 and KGS29 (C3. The results showed that all of the traits measured were increased by inoculation of cultivars with mycorrhiza. The highest plant height (165.1 cm, stem diameter (1.61 cm, flag leaf length (27.22 cm, flag leaf width (3.67 cm and ear width (5.00 cm was obtained by inoculation of seed with Glumus etanicatum, and highest ear length (19.21 cm, ear number (2.51, seed number per ear (10252.11, 1000-seed weight (17.56 g and grain yield (1967.32 kg/ha by using Glumus mossea. The highest leaf width and length belonged to local cultivar, and the highest seed yield to KGS 29 cultivar. However, differences of other traits among sorghum cultivars were not significant. Based on the experimental results it can be concluded that highest grain yield may be obtained by inoculating seeds of KGS 29 with Glumus mossea.

Hyphal Growth from Spores of the Mycorrhizal Fungus Glomus Caledonius: Effect of Amino Acids

DEFF Research Database (Denmark)

Hepper, C.M.; Jakobsen, Iver

1983-01-01

Hyphal growth from spores of Glomus caledonius (Nicol. and Gerd.) Trappe and Gerdemann was stimulated by cystine, glycine and lysine at optimum concentrations of 4.6, 556 and 825 mg l−1 respectively. When all three amino acids were supplied together in water agar, five times more growth...

Efectos del losartán sobre el glomus carotídeo en ratas normotensas adultas

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Daniel R. Grana

2006-01-01

Full Text Available Recientemente comunicamos lesiones graves en el glomus carotídeo y los ganglios autonómicos de ratas SHR y sugerimos que este efecto se debía más al aumento de la presión arterial que al envejecimiento. Posteriormente demostramos, en SHR, que el ramipril, en comparación con el atenolol, ejerce un efecto protector sobre estas estructuras más allá de la reducción de la presión arterial. Teniendo en cuenta que no existen trabajos que describan los cambios que origina el bloqueo AT1 sobre la morfología del glomus en ratas normotensas, se realizó el presente estudio con el objetivo de evaluar el efecto del losartán sobre esta estructura de ratas Wistar macho tratadas durante 8 meses. Se emplearon 14 ratas de 4 semanas de edad, divididas en grupos control y losartán (10 mg/ kg/día en el agua de bebida. La presión sistólica (PAS se registró al inicio y luego mensualmente. A la edad de 9 meses se sacrificaron las ratas y se extrajeron los glomus carotídeos, se tiñeron con hematoxilina-eosina y tricrómico de Masson y se procesaron para histomorfometría con un analizador de imágenes. El grupo control registró una PAS de 115 ± 8,1, mientras que en el grupo losartán fue de 105 ± 8,3 mm Hg (p = 0,0375. Histomorfométricamente, el grupo tratado mostró un área mayor del glomus con respecto al control (497.931 ± 48.783 versus 59.668 ± 6.196 µm2; p < 0,0001 y una relación pared/luz en las arteriolas glómicas de 0,7 ± 0,1 versus 2,7 ± 0,6, respectivamente (p < 0,0001. El grupo control mostró disminución del área glómica y un aumento de la relación pared/luz, lo cual sugiere que la atrofia de las estructuras estudiadas a través del aumento de la edad se vincula con el aporte nutricio arterial.

Organic Matter Effect on Glomus Intrarradices in Beans (Phaseolus Vulgaris L. Growth Cultivated in Soils with Two Sources of Water under Greenhouse Conditions

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A. K. Gardezi

2014-02-01

Full Text Available The objective of this research was to evaluate the effect of organic matter on the association with Glomus intrarradices and soil contamination on beans (Phaseolus vulgaris L.. The study was done under greenhouse conditions at the Montecillo Campus of the Postgraduate College, Mexico. Two soils were used, one irrigated with sewage water and the other one with clean water from a well. Half of the plants were inoculated with Glomus intrarradices. Vermicompost was used as a source of organic matter. There were highly significant increases (p≤0.05 in all the variables recorded due to the application of organic matter, and to the inoculation with Glomus intarradices. The irrigation source of the soils used for this experiment only had a significant effect (p≤0.05 on pod number and nitrogen fixation. The best growth and grain yield occurred with inoculated plants and supplementary organic matter.

Actinomicetos mineralizadores de fosfato involucrados en la interacción radical de Glomus sp. - trébol blanco

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Ruth Milena G\\u00F3mez-Vargas

2011-01-01

sp. (cepa MCR24 con la técnica del p-nitrofenil fosfato. Thermobifi da sp. (cepa MCR24 presentó la menor actividad. La inoculación de solo actinomicetos presentó valores mayores de fósforo inorgánico en suelo, mientras que la concentración de fósforo a nivel foliar fue mayor cuando había co-inoculación actinomiceto-Glomus sp., a excepción de la cepa Thermobifi da sp. (cepa MCR24. La co-inoculación con los actinomicetos y Glomus sp. estimuló la producción de biomasa y el porcentaje de colonización. Se determinó la capacidad para mineralizar fósforo orgánico por los actinomicetos al asociarse con Glomus sp. de forma sinérgica y benéfi ca tanto para la planta como para la micorriza. Se realizó el análisis de la varianza y prueba de "t" ALS (P<0,05 para comparar los promedios entre los tratamientos. Se determinó el grado de relación entre el porcentaje de micorrización y el peso seco de las plantas mediante "r" Coeficiente de Correlación, donde las plantas con los microorganismos presentaron una micorrización mayor del 70%.

Selection experiments for the optimum combination of AMF-plant-substrate for the restoration of coal mines

Energy Technology Data Exchange (ETDEWEB)

Li-ping Wang; Wei-wei Zhang; Guang-xia Guo; Kui-mei Qian; Xiao-pei Huang [China University of Mining & Technology, Xuzhou (China). School of Environment and Spatial Informatics

2009-07-15

A complex substrate consisting of fly ash, coal gangue and excess sludge was used as an experimental soil in pot culture experiments. Different soil compositions were tested by observing the growth of arbuscular mycorrhizal (AM) fungi inoculated white clover, rye grass or corn. The biomass of the host plants, the mycorrhizal colonization (MC) rate and the mycorrhizal dependency (MD) were measured. The research addresses the preferable AMF-plant-substrate combination appropriate for restoration of coal mines. We used two inoculation methods: single-inoculation with Glomus versiforme or Glomus mosseae and a dual inoculation with both G.v and G.m. The results show that G.m is the preferable fungi and that dual inoculation does not show advantages for the restoration of coal mines. White clover inoculated with AM fungi is the most suitable condition for restoration of coal mines. The best weight ratio of fly ash, coal gangue and excess sludge was found to be 20:60:20. The optimum treatment conditions of AMF-plant-activated-substrate are described. 10 refs., 2 figs., 4 tabs.

Expression of phenazine biosynthetic genes during the arbuscular mycorrhizal symbiosis of Glomus intraradices

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Dionicia Gloria León-Martínez

2012-06-01

Full Text Available To explore the molecular mechanisms that prevail during the establishment of the arbuscular mycorrhiza symbiosis involving the genus Glomus, we transcriptionally analysed spores of Glomus intraradices BE3 during early hyphal growth. Among 458 transcripts initially identified as being expressed at presymbiotic stages, 20% of sequences had homology to previously characterized eukaryotic genes, 30% were homologous to fungal coding sequences, and 9% showed homology to previously characterized bacterial genes. Among them, GintPbr1a encodes a homolog to Phenazine Biosynthesis Regulator (Pbr of Burkholderia cenocepacia, an pleiotropic regulatory protein that activates phenazine production through transcriptional activation of the protein D isochorismatase biosynthetic enzyme phzD (Ramos et al., 2010. Whereas GintPbr1a is expressed during the presymbiotic phase, the G. intraradices BE3 homolog of phzD (BGintphzD is transcriptionally active at the time of the establishment of the arbuscular mycorrhizal symbiosis. DNA from isolated bacterial cultures found in spores of G. intraradices BE3 confirmed that both BGintPbr1a and BGintphzD are present in the genome of its potential endosymbionts. Taken together, our results indicate that spores of G. intraradices BE3 express bacterial phenazine biosynthetic genes at the onset of the fungal-plant symbiotic interaction.

Arbuscular mycorrhizal fungi affect both penetration and further life stage development of root-knot nematodes in tomato.

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Vos, Christine; Geerinckx, Katleen; Mkandawire, Rachel; Panis, Bart; De Waele, Dirk; Elsen, Annemie

2012-02-01

The root-knot nematode Meloidogyne incognita poses a worldwide threat to agriculture, with an increasing demand for alternative control options since most common nematicides are being withdrawn due to environmental concerns. The biocontrol potential of arbuscular mycorrhizal fungi (AMF) against plant-parasitic nematodes has been demonstrated, but the modes of action remain to be unraveled. In this study, M. incognita penetration of second-stage juveniles at 4, 8 and 12 days after inoculation was compared in tomato roots (Solanum lycopersicum cv. Marmande) pre-colonized or not by the AMF Glomus mosseae. Further life stage development of the juveniles was also observed in both control and mycorrhizal roots at 12 days, 3 weeks and 4 weeks after inoculation by means of acid fuchsin staining. Penetration was significantly lower in mycorrhizal roots, with a reduction up to 32%. Significantly lower numbers of third- and fourth-stage juveniles and females accumulated in mycorrhizal roots, at a slower rate than in control roots. The results show for the first time that G. mosseae continuously suppresses root-knot nematodes throughout their entire early infection phase of root penetration and subsequent life stage development.

Role of VAM on growth and phosphorus nutrition of maize with low soluble phosphate fertilization Efecto de la infestación con micorrizas vesiculo arbusculares (VAM en plantas de Zea mays fertilizadas con dosis bajas de fósforo

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Amitava Rakshit

2010-01-01

Full Text Available The effect of vesicular arbuscular mycorrhizal (VAM infection on growth and P nutrition in Maize (Zea mays, cv.DDH hybrid were assessed in Oxisol pot experiment. Maize was grown inoculated with spores of VAM fungi Glomus mosseae or non-inoculated. Low soluble ferrous phosphate (FePO4.4H2O was added to the mycorrhized and non-micrrohized maized. The dry weight of mycorrhized plants with added phosphate (P were higher than in mycorrhized plants without added P or non-mycorrhized plants with added P. The amount of P in the soil samples from pots with mycorrhizal plants fertilized with P was evidently smaller than those in samples also fertilized non-mycorrhizal plants. The percentage of P was higher in tissues of fertilized mycorrhial plants than in those mycorrihzed plants without or nonmycorrhized plants with added low-soluble P. These results indicated that plants in VAM symbiosis mobilize P better from low-soluble P than non-mycorrhized plants.En condiciones de casa de malla se evaluó el efecto de la infestación con micorrizas vesículo arbusculares (VAM en la asimilación de P por plantas de maíz (Zea mays, cv.DDH hybrid cultivadas en un Oxisol. Como micorriza se utilizó el hongo Glomus mosseae. En ambos tratamientos (con micorriza y sin ella se aplicó fosfato ferroso (FePO4.4H2O. La producción de MS de maíz fue mayor cuando se aplicaron el hongo + la fuente de P. La cantidad de P en el suelo con este tratamiento fue menor que en el suelo fertilizado pero sin aplicación del hongo. En las hojas de las plantas las mayores concentraciones de P se observaron igualmente en el tratamiento micorriza + aplicación de fertilizante.

Accumulation of 137Cs and 90Sr from contaminated soil by three grass species inoculated with mycorrhizal fungi

International Nuclear Information System (INIS)

Entry, J.A.; Watrud, L.S.; Reeves, M.

1999-01-01

The use of plants to accumulate low level radioactive waste from soil, followed by incineration of plant material to concentrate radionuclides may prove to be a viable and economical method of remediating contaminated areas. We tested the influence of arbuscular mycorrhizae on 137 Cs and 90 Sr uptake by bahia grass (Paspalum notatum), johnson grass (Sorghum halpense) and switchgrass (Panicum virginatum) for the effectiveness on three different contaminated soil types. Exposure to 137 Cs or 90 Sr over the course of the experiment did not affect above ground biomass of the three grasses. The above ground biomass of bahia, johnson and switchgrass plants accumulated from 26.3 to 71.7% of the total amount of the 137 Cs and from 23.8 to 88.7% of the total amount of the 90 Sr added to the soil after three harvests. In each of the three grass species tested, plants inoculated with Glomus mosseae or Glomus intraradices had greater aboveground plant biomass, higher concentrations of 137 Cs or 90 Sr in plant tissue, % accumulation of 137 Cs or 90 Sr from soil and plant bioconcentration ratios at each harvest than those that did not receive mycorrhizal inoculation. Johnson grass had greater aboveground plant biomass, greater accumulation of 137 Cs or 90 Sr from soil and plant higher bioconcentration ratios with arbuscular mycorrhizal fungi than bahia grass and switchgrass. The greatest accumulation of 137 Cs and 90 Sr was observed in johnson grass inoculated with G. mosseae. Grasses can grow in wide geographical ranges that include a broad variety of edaphic conditions. The highly efficient removal of these radionuclides by these grass species after inoculation with arbuscular mycorrhizae supports the concept that remediation of radionuclide contaminated soils using mycorrhizal plants may present a viable strategy to remediate and reclaim sites contaminated with radionuclides

Presentation of a glomus carotid tumor as carotid sinus syndrome with syncopal episodes

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Dickschas, A.; Harmann, B.; Herzog, T.; Marienhagen, J.

1987-01-01

An 80 year old patient was referred to neurology for clarification of her episodes of syncope. A set of radiological examinations indicated a diagnosis of paraganglion of the left carotid bifurcation. Using this case, an attempt is made to provide recommendations concerning the order of step-wise visualization techniques of clarifying glomus carotid tumors. This unusual case also provides an impetus for considering the physiology and pathogenesis of different forms of carotid sinus syndrome. (orig.) [de

Mobilization and utilization of sparingly soluble phosphates by VA mycorrhizal fungus external hyphae I-32P indirectly labelling

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Yao Qing; Zhao Zijuan; Feng Gu; Li Xiaolin; Chen Baodong

2000-01-01

Red clover were grown in three-compartment boxes, and were inoculated with VA mycorrhizal fungus, Glomus mosseae. External hyphae were separated from root system by 30 μm pore size membrane. Phosphorus fertilizer indirectly labelled with 32 P and five kind of phosphates were applied in the hyphae compartment, and the ability of external hyphae to mobilize the sparingly soluble phosphates were evaluated. the results showed that external hyphae mobilized and up took Ca 2 -P, Ca 8 -P, Al-P, Fe.P, but not Ca 10 -P. The phosphorus uptake by clover from phosphates and the contribution of phosphates to clover phosphorus nutrition were ranked as Ca 2 -P > Ca 8 -P, Al-P > Fe-P

Glomus halonatum Rose & Trappe (Glomeromycota in South America: comments on the morphological characteristics of the species Glomus halonatum Rose & Trappe (Glomeromycota na América do Sul: comentários sobre a morfologia das espécies

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Bruno Tomio Goto

2009-12-01

Full Text Available Ornamented glomerospores of an arbuscular mycorrhizal fungus were collected from an area of Atlantic Forest in Goiana (Pernambuco, Brazil. The area had been cultivated with Coffea canephora Pierre ex. Froehner [=Coffea robusta (L. Linden] and Bixa orellana L., then left fallow and today is covered by herbaceous raider species. After taxonomic analysis using current descriptive and terminological criteria, the species was identified as Glomus halonatum. A description, illustrations and comments about the species are presented.Glomerosporos ornamentados de um fungo micorrízico arbuscular foram coletados em uma área de Floresta Atlântica em Goiana (Pernambuco, Brasil. A área tinha sido cultivada com Coffea canephora Pierre ex. Froehner [=Coffea robusta (L. Linden] e Bixa orellana L., abandonada, e hoje está coberta por espécies herbáceas invasoras. Após análise taxonômica usando critérios descritivos e terminológicos atuais, a espécie foi identificada como Glomus halonatum. São apresentados descrição, ilustrações e comentários sobre a espécie.

A search for glomuferrin: a potential siderophore of arbuscular mycorrhizal fungi of the genus Glomus.

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Winkelmann, Günther

2017-08-01

Most fungi are known to synthesize siderophores under iron limitation. However, arbuscular mycorrhizal fungi (AM fungi) have so far not been reported to produce siderophores, although their metabolism is iron-dependent. In an approach to isolate siderophores from AM fungi, we have grown plants of Tagetes patula nana in the presence of spores from AM fungi of the genus Glomus (G. etunicatum, G. mossae & unidentified Glomus sp.) symbiotically under iron limitation and sterile conditions. A siderophore was isolated from infected roots after 2-3 weeks of growth in pots containing low-iron sand with Hoagland solution. HPLC analysis of the root cell lysate revealed a peak at a retention time of 6.7 min which showed iron-binding properties in a chrome azurol S test. The compound was isolated by preparative HPLC and the structure was determined by high resolution electrospray FTICR-MS and GC/MS analysis of the hydrolysis products. From an observed absolute mass to charge ratio (m/z) of 401.11925 [M+H] + with a relative mass error of ∆ = 0.47 ppm an elemental composition of C 16 H 21 N 2 O 10 [M+H] + was derived, suggesting a molecular weight of 400 Da for glomuferrin. Corresponnding ion masses of m/z 423.10 and m/z 439.06 were asigned to the Na-adduct and K-adduct respectively. A mass of 455.03836 confirmed an Fe- complex with an elemental composition of C 16 H 19 N 2 O 10 Fe (∆ = 0.15 ppm). GC/MS analysis of the HCl lysate (6 N HCL, 12 h) revealed 1,4 butanediamine. Thus the proposed structure of the isolated siderophore from Glomus species consisted of 1,4 butanediamine amidically linked to two dehydrated citrate residues, similar to the previously identified bis-amidorhizoferrin. Thus, the isolated siderophore (glomuferrin) is a member of the rhizoferrin family previously isolated from fungi of the Mucorales (Zygomycetes).

Effect Mycorrhizal Fungi on Reduction of Drought Stress Effect in Some Growth Traits of Sesame (Sesamum indicum L. Genotypes

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esmaeel gholinezhad

2018-02-01

Full Text Available Introduction Sesame (Sesamum indicum plays an important role in human health because of its high oil capacity (47 - 52%.. Arbuscular mycorrhizal symbiosis protects host plants against the detrimental effects of drought stress through mechanisms of drought avoidance. Strategies of drought avoidance in mycorrhizal plants rely on the ability to maintain an adequate hydration status on the level of whole plants as characterized by relative water content. So the aim of current study was to evaluate the symbiosis effect of two different species of mycorrhizae fungi on yield and physiological characteristics of sesame landraces under different drought stress levels in Urmia. Materials and Methods This experiment was conducted in 2014-2015 by using factorial split plot based on randomized complete block design with three replications in the research field of Urmia agricultural high school with 12 Km distance from Urmia. The main plot factor was consisted of different irrigation levels: normal irrigation (irrigation after 70 mm evaporation of crop (ETC, moderate drought stress (irrigation after 90 mm evaporation of crop (ETC and severe drought stress (irrigation after 110 mm evaporation of crop (ETC. Also three levels of Sub plot factors included two species of mycorrhizae fungi Glomus mosseae, Glomus intraradices and no -inoculation (control. Sub-sub plot factorss consisted of eight landraces of sesames (named Jiroft13, Zanjan Tarom landrace, Moghan landrace, Naz of several branches, TC-25,TS-3, Darab 14 and Dashtestan 5. Then Leaf Area Index (LAI, Total Dry Matter (TDM, Leaf relative water content (RWC, Specific leaf area (SLA, Specific leaf weight (SLW, Leaf Area Ratio (LAR, Leaf Weight Ratio (LWR of different landraces calculated using SAS and MSTATC. To compare the means, Tukey's test at 5% probability level was used. Results and Discussion The results of the experiment showed that with increasing the levels of drought stress, RWC, LAI, seed yield

Glomus etunicatum root inoculation and foliar application of acetyl salicylic acid induced nacl tolerance by regulation of nacl and lenhx1 gene expression and improved photosynthetic performance in tomato seedlings

International Nuclear Information System (INIS)

Ghazanfar, B.; Chihui, C.; Liu, H.; Ahmad, I.; Khan, A.R.

2016-01-01

Salinity stress hampers plant growth and cause significant yield losses thus induction of salinity stress tolerance in crop plants is one of major goals of agriculture research. Arbuscular mycorhizae fungi Glomus etunicatum and acetyl salicylic acid were tested for induction of NaCl stress tolerance in tomato seedlings, cultivar No. 4. The seedlings were inoculated with Glomus etunicatum and exogenously sprayed with acetyl salicylic acid (0.30 mM) followed by salinity stress (150 mM). It was observed that both Glomus etunicatum and acetyl salicylic acid (singly or in combination) were significantly effective to minimize the injurious effects of salinity by improving root morphological parameters (length, diameter, surface area, volume and number of tips, nodes, bifurcations and connections), photosynthetic parameters (net photosynthesis Pn, stomatal conductance Gs) and chlorophyll contents compared to sole salinity treatment. The bio-inoculant Glomus etunicatum and chemical ameliorator acetyl salicylic acid also notably improved vegetative (fresh and dry weights) and reproductive growth (percent seedlings with flower buds and opened flowers, number of flower buds and opened flowers per seedling) of the plants as compared to the sole salinity treatment. The studied salt responsive genes (LeNHX1 and NaCl) were also regulated to different extents in seedling roots and leaves which was consistent with enhanced salinity stress tolerance. From these observations it is suggested that the individual or synergetic use of the AMF (Glomus etunicatum) and acetyl salicylic acid can be useful for tomato cultivation in the marginally salinity effected soils and warrants further investigations. (author)

Correlations of Glomalin Contents and PAHs Removal in Alfalfa-vegetated Soils with Inoculation of Arbuscular Mycorrhizal Fungi

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YANG Zhen-ya

2016-07-01

Full Text Available The correlations of glomalin contents and removal of phenanthrene and pyrene as representative polycyclic aromatic hydrocarbons (PAHs in soils with inoculation of arbuscular mycorrhizal fungi(AMF were investigated. The test AMF included Glomus etunicatum(Ge, Glomus mosseae(Gm, and Glomus lamellosum(Gla, and the host plant was alfalfa(Medicago sativa L.. The AMF hyphal density and contents of easily extractable glomalin and total glomalin in AMF-inoculated soils were observed to increase with cultivation time from 35 d to 75 d. Comparing with the control treatment(CK without AMF inoculation, the contents of easily extractable glomalin in soil increased 48.58%, 55.99% and 50.23%, and total glomalin contents increased 38.75%, 50.95% and 46.12% with Ge, Gm and Gla inoculation after 75 d, respectively. AMF inoculation promoted the removal of test PAHs in soils. The removal rates of phenanthrene and pyrene in soils with AMF enhanced in 35~75 d. 83.4%~92.7%, 82.1%~93.8% and 86.9%~93.4% of phenanthrene and 42.2%~63.5%, 43.7%~69.2% and 44.6%~66.4% of pyrene in soils with Ge, Gm, Gla were removed in 75 d respectively. AMF hyphal density and total glomalin contents were observed to be significantly positively correlated with the removal rates of PAHs in soils, indicating that the colonization of AMF enhanced hyphal density and total glomalin contents and thus promoted the degradation of PAHs in the soil environments.

Glomus drummondii and G. walkeri, two new species of arbuscular mycorrhizal fungi (Glomeromycota).

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Błaszkowski, Janusz; Renker, Carsten; Buscot, François

2006-05-01

Two new ectocarpic arbuscular mycorrhizal fungal species, Glomus drummondii and G. walkeri (Glomeromycota), found in maritime sand dunes of northern Poland and those adjacent to the Mediterranean Sea are described and illustrated. Mature spores of G. drummondii are pastel yellow to maize yellow, globose to subglobose, (58-)71(-85) micromdiam, or ovoid, 50-80x63-98 microm. Their wall consists of three layers: an evanescent, hyaline, short-lived outermost layer, a laminate, smooth, pastel yellow to maize yellow middle layer, and a flexible, smooth, hyaline innermost layer. Spores of G. walkeri are white to pale yellow, globose to subglobose, (55-)81(-95) micromdiam, or ovoid, 60-90x75-115 microm, and have a spore wall composed of three layers: a semi-permanent, hyaline outermost layer, a laminate, smooth, white to pale yellow middle layer, and a flexible, smooth, hyaline innermost layer. In Melzer's reagent, only the inner- and outermost layers stain reddish white to greyish rose in G. drummondii and G. walkeri, respectively. Both species form vesicular-arbuscular mycorrhizae in one-species cultures with Plantago lanceolata as the host plant. Phylogenetic analyses of the ITS and parts of the LSU of the nrDNA of spores placed both species in Glomus Group B sensu Schüssler et al. [Schüssler A, Schwarzott D, Walker C, 2001. A new fungal phylum, the Glomeromycota: phylogeny and evolution. Mycolological Research 105: 1413-1421.].

Arbuscular mycorrhizal fungi enhance both absorption and stabilization of Cd by Alfred stonecrop (Sedum alfredii Hance) and perennial ryegrass (Lolium perenne L.) in a Cd-contaminated acidic soil.

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Hu, Junli; Wu, Shengchun; Wu, Fuyong; Leung, Ho Man; Lin, Xiangui; Wong, Ming Hung

2013-10-01

A greenhouse pot experiment was conducted to compare the phytoextraction efficiencies of Cd by hyper-accumulating Alfred stonecrop (Sedum alfredii Hance) and fast-growing perennial ryegrass (Lolium perenne L.) from a Cd-contaminated (1.6 mg kg(-1)) acidic soil, and their responses to the inoculations of two arbuscular mycorrhizal (AM) fungal strains, Glomus caledonium 90036 (Gc) and Glomus mosseae M47V (Gm). Ryegrass and stonecrop were harvested after growing for 9 and 27 wk, respectively. Without AM fungal inoculation, the weekly Cd extraction by stonecrop (8.0 μg pot(-1)) was 4.3 times higher than that by ryegrass (1.5 μg pot(-1)). Both Gc and Gm significantly increased (P soil acid phosphatase activities, and available P concentrations, and thereby plant P absorptions (except for Gm-inoculated ryegrass), shoot biomasses, and Cd absorptions (except for Gm-inoculated stonecrop), while only Gc-inoculated stonecrop significantly accelerated (P soil pH. The results suggested the potential application of hyper-accumulating Alfred stonecrop associated with AM fungi (notably Gc) for both extraction and stabilization of Cd in the in situ treatment of Cd-contaminated acidic soil. Copyright © 2013 Elsevier Ltd. All rights reserved.

Screening of efficient arbuscular mycorrhizal fungi for Azadirachta indica under nursery condition: a step towards afforestation of semi-arid region of western India

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K. Banerjee

2013-01-01

Full Text Available To optimize nursery practices for efficient plant production procedures and to keep up to the ever growing demand of seedlings, identification of the most suitable species of arbuscular mycorrhizal fungi (AMF, specific for a given tree species, is clearly a necessary task. Sixty days old seedlings of Neem (Azadirachta indica A. Juss raised in root trainers were inoculated with six species of AMF and a mixed inoculum (consortia and kept in green house. Performances of the treatments on this tree species were evaluated in terms of growth parameters like plant height shoot collar diameter, biomass and phosphorous uptake capabilities. Significant and varied increase in the growth parameters and phosphorous uptake was observed for most of the AMF species against control. Consortia culture was found to be the best suited AMF treatment for A.indica, while Glomus intraradices and Glomus mosseae were the best performing single species cultures. It is the first time in the state of Gujarat that a wide variety of AMF species, isolated from the typical semi-arid region of western India, were tested for the best growth performance with one of the most important tree species for the concerned region.

Mixed arbuscular mycorrhizal (AM) fungal application to improve growth and arsenic accumulation of Pteris vittata (As hyperaccumulator) grown in As-contaminated soil.

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Leung, H M; Leung, A O W; Ye, Z H; Cheung, K C; Yung, K K L

2013-08-01

A greenhouse pot experiment was conducted to study the effects of three types of single inoculum [indigenous mycorrhizas (IM) isolated from As mine, Glomus mosseae (GM) and Glomus intraradices (GI)] and two types of mixed inoculum (mixed with IM and either GM or GI) on the growth response of Pteris vittata (hyperaccumulator) and Cynodon dactylon (non-hyperaccumulator) at three levels of As concentrations (0, 100 and 200mgkg(-1)). Both mycorrhizal plants exhibited significantly higher biomass, and N and P accumulation in its tissue than the control. Among the mycorrhizal inoculum, the mixed inoculum IM/GM promoted substantially higher mycorrhizal colonization and arsenate reductase activity in P. vittata than C. dactylon, among all As levels. The portion of Paris arbuscular mycorrhizal structure (observed in colonized roots) together with the highest As translocation factor of 10.2 in P. vittata inoculated with IM/GM was also noted. It was deduced that IM/GM inoculum may be the best choice for field inoculation at any contaminated lands as the inoculum exhibited better adaptation to variable environmental conditions and hence benefited the host plants. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Colonization with Arbuscular Mycorrhizal Fungi Promotes the Growth of Morus alba L. Seedlings under Greenhouse Conditions

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Nan Lu

2015-03-01

Full Text Available Morus alba L. is an important tree species planted widely in China because of its economic value. In this report, we investigated the influence of two arbuscular mycorrhizal fungal (AMF species, Glomus mosseae and Glomus intraradices, alone and together, on the growth of M. alba L. seedlings under greenhouse conditions. The growth parameters and physiological performance of M. alba L. seedlings were evaluated 90 days after colonization with the fungi. The growth and physiological performance of M. alba L. seedlings were significantly affected by the AMF species. The mycorrhizal seedlings were taller, had longer roots, more leaves and a greater biomass than the non-mycorrhizae-treated seedlings. In addition, the AMF species-inoculated seedlings had increased root activity and a higher chlorophyll content compared to non-inoculated seedlings. Furthermore, AMF species colonization increased the phosphorus and nitrogen contents of the seedlings. In addition, simultaneous root colonization by the two AMF species did not improve the growth of M. alba L. seedlings compared with inoculation with either species alone. Based on these results, these AMF species may be applicable to mulberry seedling cultivation.

Homogenous stands of a wetland grass harbour diverse consortia of arbuscular mycorrhizal fungi.

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Wirsel, Stefan G R

2004-05-01

A molecular approach was applied to investigate the colonisation of arbuscular mycorrhizal fungi (AMF) on the wetland grass Phragmites australis. A PCR assay targeting the traditional families of the Glomeromycota yielded products that were used to construct libraries of 18S rDNA. Five hundred and forty six clones were typed by restriction analysis and 76 representatives were sequenced. The majority corresponded to a wide range of taxa within Glomus group A, a few belonged to the "Diversisporaceae" and none to the genera Scutellospora or Acaulospora. Among these sequences, some were very similar to those reported earlier, e.g. Glomus mosseae and G. fasciculatum, other pointed to various new taxa. Although this wetland habitat harboured just one single plant species, phylogenetic analysis exhibited 21 AMF phylotypes, which is in the same range as reported for other natural ecosystems composed of more diverse host communities. Diversity indices supported the perception that the AMF mycoflora associated with this natural grass "monoculture" is not depauperate as it had been described for grasses of crop monocultures. Soil conditions determined the mycorrhizal state of the host, since AMF were not detected at the lakeward front of the reed belt, which is permanently waterlogged.

Can Arbuscular Mycorrhizal Fungi Reduce the Growth of Agricultural Weeds?

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Veiga, Rita S. L.; Jansa, Jan; Frossard, Emmanuel; van der Heijden, Marcel G. A.

2011-01-01

Background Arbuscular mycorrhizal fungi (AMF) are known for their beneficial effects on plants. However, there is increasing evidence that some ruderal plants, including several agricultural weeds, respond negatively to AMF colonization. Here, we investigated the effect of AMF on the growth of individual weed species and on weed-crop interactions. Methodology/Principal Findings First, under controlled glasshouse conditions, we screened growth responses of nine weed species and three crops to a widespread AMF, Glomus intraradices. None of the weeds screened showed a significant positive mycorrhizal growth response and four weed species were significantly reduced by the AMF (growth responses between −22 and −35%). In a subsequent experiment, we selected three of the negatively responding weed species – Echinochloa crus-galli, Setaria viridis and Solanum nigrum – and analyzed their responses to a combination of three AMF (Glomus intraradices, Glomus mosseae and Glomus claroideum). Finally, we tested whether the presence of a crop (maize) enhanced the suppressive effect of AMF on weeds. We found that the growth of the three selected weed species was also reduced by a combination of AMF and that the presence of maize amplified the negative effect of AMF on the growth of E. crus-galli. Conclusions/Significance Our results show that AMF can negatively influence the growth of some weed species indicating that AMF have the potential to act as determinants of weed community structure. Furthermore, mycorrhizal weed growth reductions can be amplified in the presence of a crop. Previous studies have shown that AMF provide a number of beneficial ecosystem services. Taken together with our current results, the maintenance and promotion of AMF activity may thereby contribute to sustainable management of agroecosystems. However, in order to further the practical and ecological relevance of our findings, additional experiments should be performed under field conditions. PMID

Influence of arbuscular mycorrhizal fungus Glomus intraradices on accumulation of radiocaesium by plant species

International Nuclear Information System (INIS)

Dubchak, S.V.

2012-01-01

The role of arbuscular mycorrhizal fungus Glomus intraradices in 134 Cs isotope by different plant species is studied. The impact of radiocaesium on mycorrhizal development and functioning of plant photosynthetic apparatus is considered. The possibility of mycorrhizal symbiosis application in phyto remediation of radioactively contaminated areas is analyzed. It is found that colonization pf plants with arbuscular mycorrhizal fungus resulted in significant decrease of radiocesium concentration in their aboveground parts, while it did not have considerable impact on the radionuclide uptake by plant root system

Phosphate concentration and arbuscular mycorrhizal colonisation influence the growth, yield and expression of twelve PHT1 family phosphate transporters in foxtail millet (Setaria italica.

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S Antony Ceasar

Full Text Available Phosphorus (P is an essential element which plays several key roles in all living organisms. Setaria italica (foxtail millet is a model species for panacoid grasses including several millet species widely grown in arid regions of Asia and Africa, and for the bioenergy crop switchgrass. The growth responses of S. italica to different levels of inorganic phosphate (Pi and to colonisation with the arbuscular mycorrhizal fungus Funneliformis mosseae (syn. Glomus mosseae were studied. Phosphate is taken up from the environment by the PHT1 family of plant phosphate transporters, which have been well characterized in several plant species. Bioinformatic analysis identified 12 members of the PHT1 gene family (SiPHT1;1-1;12 in S. italica, and RT and qPCR analysis showed that most of these transporters displayed specific expression patterns with respect to tissue, phosphate status and arbuscular mycorrhizal colonisation. SiPHT1;2 was found to be expressed in all tissues and in all growth conditions tested. In contrast, expression of SiPHT1;4 was induced in roots after 15 days growth in hydroponic medium of low Pi concentration. Expression of SiPHT1;8 and SiPHT1;9 in roots was selectively induced by colonisation with F. mosseae. SiPHT1;3 and SiPHT1;4 were found to be predominantly expressed in leaf and root tissues respectively. Several other transporters were expressed in shoots and leaves during growth in low Pi concentrations. This study will form the basis for the further characterization of these transporters, with the long term goal of improving the phosphate use efficiency of foxtail millet.

Phosphate concentration and arbuscular mycorrhizal colonisation influence the growth, yield and expression of twelve PHT1 family phosphate transporters in foxtail millet (Setaria italica).

Science.gov (United States)

Ceasar, S Antony; Hodge, Angela; Baker, Alison; Baldwin, Stephen A

2014-01-01

Phosphorus (P) is an essential element which plays several key roles in all living organisms. Setaria italica (foxtail millet) is a model species for panacoid grasses including several millet species widely grown in arid regions of Asia and Africa, and for the bioenergy crop switchgrass. The growth responses of S. italica to different levels of inorganic phosphate (Pi) and to colonisation with the arbuscular mycorrhizal fungus Funneliformis mosseae (syn. Glomus mosseae) were studied. Phosphate is taken up from the environment by the PHT1 family of plant phosphate transporters, which have been well characterized in several plant species. Bioinformatic analysis identified 12 members of the PHT1 gene family (SiPHT1;1-1;12) in S. italica, and RT and qPCR analysis showed that most of these transporters displayed specific expression patterns with respect to tissue, phosphate status and arbuscular mycorrhizal colonisation. SiPHT1;2 was found to be expressed in all tissues and in all growth conditions tested. In contrast, expression of SiPHT1;4 was induced in roots after 15 days growth in hydroponic medium of low Pi concentration. Expression of SiPHT1;8 and SiPHT1;9 in roots was selectively induced by colonisation with F. mosseae. SiPHT1;3 and SiPHT1;4 were found to be predominantly expressed in leaf and root tissues respectively. Several other transporters were expressed in shoots and leaves during growth in low Pi concentrations. This study will form the basis for the further characterization of these transporters, with the long term goal of improving the phosphate use efficiency of foxtail millet.

Effects of Metal Phytoextraction Practices on the Indigenous Community of Arbuscular Mycorrhizal Fungi at a Metal-Contaminated Landfill

Science.gov (United States)

Pawlowska, Teresa E.; Chaney, Rufus L.; Chin, Mel; Charvat, Iris

2000-01-01

Phytoextraction involves use of plants to remove toxic metals from soil. We examined the effects of phytoextraction practices with three plant species (Silene vulgaris, Thlaspi caerulescens, and Zea mays) and a factorial variation of soil amendments (either an ammonium or nitrate source of nitrogen and the presence or absence of an elemental sulfur supplement) on arbuscular mycorrhizal (AM) fungi (Glomales, Zygomycetes) at a moderately metal-contaminated landfill located in St. Paul, Minn. Specifically, we tested whether the applied treatments affected the density of glomalean spores and AM root colonization in maize. Glomalean fungi from the landfill were grouped into two morphotypes characterized by either light-colored spores (LCS) or dark-colored spores (DCS). Dominant species of the LCS morphotype were Glomus mosseae and an unidentified Glomus sp., whereas the DCS morphotype was dominated by Glomus constrictum. The density of spores of the LCS morphotype from the phytoremediated area was lower than the density of these spores in the untreated landfill soil. Within the experimental area, spore density of the LCS morphotype in the rhizosphere of mycorrhizal maize was significantly higher than in rhizospheres of nonmycorrhizal S. vulgaris or T. caerulescens. Sulfur supplement increased vesicular root colonization in maize and exerted a negative effect on spore density in maize rhizosphere. We conclude that phytoextraction practices, e.g., the choice of plant species and soil amendments, may have a great impact on the quantity and species composition of glomalean propagules as well as on mycorrhiza functioning during long-term metal-remediation treatments. PMID:10831433

Influence of arbuscular mycorrhizal fungus Glomus intra-radices on accumulation of radiocaesium by plant species

International Nuclear Information System (INIS)

Dudchak, S.V.

2012-01-01

The role of arbuscular mycorrhizal fungus Glomus intra-radices in 134 Cs isotope uptake by different plant species is studied. The impact of radiocaesium on mycorrhizal development and functioning of plant photosynthetic apparatus is considered. The possibility of mycorrhizal symbiosis application in phytoremediation of radioactively contaminated areas is analyzed.It is found that colonization of plants with arbuscular mycorrhizal fungus resulted in significant decrease of radiocaesium concentration in their aboveground parts, while it did not have considerable impact on the radionuclide uptake by plant root system

Fungos micorrízicos arbusculares em bananeiras cultivadas no Vale do Submédio São Francisco Arbuscular mycorrhizal fungi associated with roots of banana cultivated in the Submédio São Francisco Valley

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Adriana Mayumi Yano de Melo

1997-12-01

Full Text Available Na região do Vale do São Francisco, onde a exploração da agricultura irrigada é a principal responsável pela alta produção de frutas para exportação, a banana é uma das culturas que mais tem se expandido em área cultivada. Com o objetivo de registrar os fungos micorrízicos arbusculares associados a essa cultura, foram coletadas, sob a parte aérea da bananeira, amostras de solo da rizosfera, em quatro áreas com diferentes características de solo, sendo identificadas as espécies: Acaulospora longula Spain & Schenck, A. morrowiae Spain & Schenck, A. rehmii Sieverding & Toro, A. scrobiculata Trappe, A. spinosa Walker & Trappe, A. tuberculata Janos & Trappe, Entrophospora infrequens (Hall Ames & Schneider, Gigaspora ramisporophora Spain, Sieverding & Schenck, Glomus diaphanum Morton & Walker, G. etunicatum Becker & Gerd., G. intraradices Schenck & Smith, G. macrocarpum Tui. & Tui., G. mosseae (Nicol. & Gerd. Gerd. & Trappe, G. occultum Walker e Scutellospora sp. A percentagem de colonização das raízes de bananeiras nas diferentes áreas foi em média 55%.In the region of the São Francisco Valley, where irrigated agriculture is responsable for high production of fruits for exportation, banana is one of the most expanded crops in cultivated areas. In order to know the arbuscular mycorrhizal fungi associated with this crop, samples from the rhizosphere of banana plants were collected in four areas with different soil characteristics, being identified the species: Acaulospora longula Spain & Schenck, A. morrowiae Spain & Schenck, A. rehmii Sieverding & Toro, A. scrobiculata Trappe, A. spinosa Walker & Trappe, A. tuberculata Janos & Trappe, Entrophospora infrequens (Hall Ames & Schneider, Gigaspora ramisporophora Spain, Sieverding & Schenck, Glomus diaphanum Morton & Walker, G. etunicatum Becker & Gerd., G. intraradices Schenck & Smith, G. macrocarpum Tui. & Tui., G. mosseae (Nicol. & Gerd. Gerd. & Trappe, G. occultum Walker and

Glomus Tumor of the Neck Detected With 99mTc EDDA HYNIC-TOC.

Science.gov (United States)

Girotto, Neva; Bogović-Crnčić, Tatjana; Grbac-Ivanković, Svjetlana; Valković-Zujić, Petra

2017-10-01

A 54-year-old woman was referred to thyroid evaluation because of a lump on the left side of the neck. Ultrasound exam did not show any thyroid abnormality, but highly perfused nodule at the left common carotid artery bifurcation was found. Because of the specific location, somatostatin receptor scintigraphy with Tc EDDA HYNIC-TOC was performed, starting with perfusion images and followed with SPECT/CT imaging at 2 and 4 hours. Well-perfused nodule with intensive accumulation and no other visible pathology in the body raised suspicion of a glomus tumor, consistent with MR exam performed later. Subsequent surgical removal confirmed carotid paraganglioma.

Molecular diversity of arbuscular mycorrhizal fungi in onion roots from organic and conventional farming systems in the Netherlands.

Science.gov (United States)

Galván, Guillermo A; Parádi, István; Burger, Karin; Baar, Jacqueline; Kuyper, Thomas W; Scholten, Olga E; Kik, Chris

2009-06-01

Diversity and colonization levels of naturally occurring arbuscular mycorrhizal fungi (AMF) in onion roots were studied to compare organic and conventional farming systems in the Netherlands. In 2004, 20 onion fields were sampled in a balanced survey between farming systems and between two regions, namely, Zeeland and Flevoland. In 2005, nine conventional and ten organic fields were additionally surveyed in Flevoland. AMF phylotypes were identified by rDNA sequencing. All plants were colonized, with 60% for arbuscular colonization and 84% for hyphal colonization as grand means. In Zeeland, onion roots from organic fields had higher fractional colonization levels than those from conventional fields. Onion yields in conventional farming were positively correlated with colonization level. Overall, 14 AMF phylotypes were identified. The number of phylotypes per field ranged from one to six. Two phylotypes associated with the Glomus mosseae-coronatum and the G. caledonium-geosporum species complexes were the most abundant, whereas other phylotypes were infrequently found. Organic and conventional farming systems had similar number of phylotypes per field and Shannon diversity indices. A few organic and conventional fields had larger number of phylotypes, including phylotypes associated with the genera Glomus-B, Archaeospora, and Paraglomus. This suggests that farming systems as such did not influence AMF diversity, but rather specific environmental conditions or agricultural practices.

Mecanismos de adaptación de maíz asociado a Glomus spp. en suelos con bajo fósforo disponible

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Roveda Gabriel

2007-12-01

Full Text Available

La deficiencia de fósforo es uno de los mayores limitantes para la productividad agrícola en el trópico. Esta investigación está orientada a estudiar los mecanismos de adaptación de maíz asociado a Glomus spp. La investigación se realizó bajo condiciones controladas en los laboratorios del Corpoica. El diseño experimental utilizado fue bloques completos al azar, con seis tratamientos y seis repeticiones: tres tratamientos con 1, 40 y 100 mg·kg^-1 de P en el suelo y los anteriores niveles de P más Glomus spp. Los resultados experimentales confirman una disminución en área foliar y materia seca relacionadas con bajo P en suelo, 20 días de la emergencia. Como mecanismos de adaptación a las deficiencias de P, las plántulas traslocan carbohidratos a la raíz en detrimento de las hojas, esto modifica el balance de la materia seca. Este mecanismo fue evidente a 10 días después del estrés. Plantas asociadas a Glomus mayores tasas de crecimiento, nutrición mineral (N, P, K, Ca, Mg, S y concentración de azúcares en tejido, debido al papel P en la síntesis de carbohidratos. Plantas micorrizadas aumentaron los niveles de proteínas en tejido, con 1 y 40 mg·kg^{- 1} de P en suelo. Los resultados sugieren queGlomus spp. contribuye con la síntesis de proteínas de estrés en planta, por déficit de P en el suelo. El estrés conduce a la expresión diferencial de la información genética, produciendo cambios en la síntesis de nuevas proteínas, llamadas micorrizinas, las cuales posiblemente dotan a las plantas con la capacidad de adaptación al estrés.

The Effect of Mycorrhizal Inoculation of Fenugreek (Trigonella foenum-graecum L. on its Yield and Some Physiological Characteristics Under Drought Conditions

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Madineh Bijhani

2015-11-01

Full Text Available To study the effects of mycorrhizal inoculation of fenugreek (Trigonella foenum-graecum L. plants and on its growth and yield under drought stress conditions a greenhouse experiment was carried out in split plot using a randomized complete block design at Zabol University green house in 2013. Treatments were three drought stresses: control, mild stress and severe stress (70, 50 and 30% FC assigned to main plots, and three species of mycorrhizal treatments (Glomus intraradices, G. versiform, G. mosseae and non-inoculation as control to sub-plots. The effects of drought on all traits under study were significant, and reduced number of leaves per plant, plant height, root length, chlorophyll b and total chlorophyll by 15.6, 7.6, 10.7, 2.5 and 8.4 % and increased proline and carbohydrates by 38.6 and 17.7 % as compared with the control. Mycorrhizal treatments did not affect the amount of carbohydrates and proline content significantly. Interaction of mycorrhiza and drought stress was significant on grain yield, chlorophyll a and total chlorophyll. Among the mycorrhizal strains G. mosseae affected the traits significantly under drought conditions. The results suggested that mycorrhizal treatments of plants at different drought stresses could improve grain yield of fenugreek and reduce the negative effects of drought by increasing photosynthetic pigments and other quantitative and qualitative traits.

Lead tolerance of Populus nigra in symbiosis with arbuscular mycorrhizal fungi in relation to physiological parameters

International Nuclear Information System (INIS)

Salehi, A.; Tabari, M.; Mohammadi Goltapeh, E.; Shirvani, A.

2016-01-01

With the aim to examine lead tolerance of Populus nigra (clone 62/154) in symbiosis witharbuscular mycorrhizal fungi, a greenhouse experiment was carried out in a factorial randomized complete scheme with two factors 1) fungal inoculation in 4 levels (control, inoculation with Glomus mosseae, inoculation with G. intraradices and inoculation with G. mosseae+G. intraradices) and 2) lead in 4 levels (0, 100, 500 and 1000 mg kg-1 soil). Mycorrhizal colonization and physiological parameters of plants were measured at the end of growth season. Results showed that at all Pb levels, the percentage of root mycorrhizal colonization in fungal treatments was significantly higher than that in control treatment (without fungal inoculation), however without significant differences between 3 fungal treatments. Pb treatments had no significant effect on root mycorrhizal colonization of P. nigra plants. Also, photosynthesis, stomatal conductance, transpiration, intercellular CO2 concentration and water use efficiency of P. nigra plants had no significant inhibitory effects versus the control found under Pb and fungal treatments or their interaction.The results of present study demonstrated that fungal treatments had no significant effects on physiological parameters and Pb tolerance of P. nigraplants. While, in relation to mycorrhizal colonization and physiological parameters, P. nigra clone 62/154 showeda good tolerance to Pb stress. So, in further investigations of phytoremediation of lead-contaminated soils, this clone can be considered as a proposed species.

Fungicide Effect on Glomus Intrarradices in Different Genotypes of Beans (Phaseolus Vulgaris L., OAT (Avena Sativa L., and Wheat (Triticum Aaestivum L. Growth Cultivated in Two Soil Types under Greenhouse Conditions

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Abdul Khalil Gardezi

2013-12-01

Full Text Available The objective of this research was to evaluate the effect of fungicides on the association with Glomus intraradices and soil contamination on three genotypes of beans (Phaseolus vulgaris L., one of oat (Avena sativa L., and another one of wheat (Triticum aestivum L.. The study was done under greenhouse conditions at the Montecillo Campus of the Postgraduate College, Mexico. Two soils were used, one irrigated with sewage water and the other one with clean water from a well. Half of the plants were inoculated with Glomus intraradices. Metacaptan was used as a fungicide applied to half of the seeds. The pH of the soil was alkaline. Electric conductivity, and organic matter, nitric and ammoniac nitrogen, phosphorous, copper and nickel quantities were higher on the soils irrigated with sewage water. The soil contamination did not affect significantly plant responses in this study. It is concluded that endomycorrhiza inoculation (Glomus intraradices gave better growth and yield, especially in beans. The application of fungicides improved plant growth.

Changes in Nutrient Content of Root and Grain of Wheat Cultivars Inoculated by Azospirillum and Mycorrhiza

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M. Jiriaie

2016-02-01

Full Text Available Introduction: Providing the nutritional requirements of agricultural crops by non-chemical resources is a new approach in the organic farming that has attracted the attention of both the researchers and the consumers in recent years. Therefore, it is highly important to find new fertilizer resources that are both economically able to provide the nutritional needs of the crop plants and have no adverse effects on the consumers and the environment. Materials and Methods: With this approach, an experiment was conducted in the research station of Shahid Chamran University of Ahvaz, Iran in 2012-13. The experimental design was factorial based on randomized complete blocks design with three replications. The treatments including Mycorrhizal fungi in three levels (i.e. no use of strain; use of Glomus intraradices strain; and use of Glomus mosseae strain, bacteria Azospirillum lipoferum in two-levels (i.e. non-inoculated and inoculated and wheat cultivars in three levels (i.e. Chamran; Dena; and Behrang. The measured parameters include the concentration of macronutrients (i.e. nitrogen, phosphorus and potassium and some micronutrients (i.e. zinc, iron and manganese in two part seed and the root of wheat. Results and Discussion: Surveying the elements content in the root and the grain indicated a significant and positive effect of the use the Azospirillum and Mycorrhiza to improve the concentration of the elements in wheat cultivars. However, the simultaneous use of these microorganisms led to an increase of the effects of their application on their assessed traits.Finally the highest concentration of N (2.21 present, P (0.50 present and Fe (33.88 mg.kg-1 were observed in the grain; the highest concentration of K (0.93 present and 0.54 present and Mn (43.11 and 23.63 mg.kg-1 were observed in the grain and root, respectively. Moreover, the highest concentration of Zn in the root (19.70 mg.kg-1 was obtained from inoculation of C.V Dena seeds with

Effect of Arbuscular Mycorrhizal Fungi Glomus spp. Inoculation on Alfalfa Growth in Soils with Copper Efecto de la Inoculación con Hongos Micorrízicos Arbusculares Glomus spp. sobre el Crecimiento de Alfalfa en Suelos con Cobre

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Daniela Novoa M

2010-06-01

Full Text Available Soils near mining centers usually have high heavy metal (HM levels. It has been found that some plants associated with arbuscular mycorrhizal fungi (AMF improve growth and tolerance to HM in soils. This symbiosis is a biological resource for degraded soil recovery. The objective of this study was to determine the effect of inoculating AMF (Glomus spp. on alfalfa (Medicago sativa L. growth in agricultural soils with different copper (Cu levels for degraded soil recovery. To this effect, alfalfa seeds were grown in soils from the Catemu and Casablanca valleys and inoculated with AMF. Plant height, stem diameter, and number of leaves were measured weekly. Dry matter, mycorrhizal colonization, and Cu concentration in alfalfa plant tissues were measured after 81 days. Inoculation increased plant height by 24%, stem diameter by 11%, and number of leaves by 34%. Inoculation had a significant effect (p ≤ 0.05 on alfalfa plants that were grown in soil with the highest Cu concentration, but had no effect on Cu accumulation in alfalfa plant tissues. A direct relationship was observed between Cu accumulation in alfalfa and Cu concentration in soils. It was concluded that alfalfa inoculated with Glomus spp. is applicable to the soil recovery process whenever soil properties can ensure inoculum effectiveness on alfalfa growth, and avoid toxicity by excessive Cu in alfalfa plant tissues.Los suelos cercanos a centros de actividad minera suelen presentar altos niveles de metales pesados (HM. Se ha encontrado que algunas plantas asociadas a hongos micorrízicos arbusculares (AMF mejoran su crecimiento y tolerancia a los HM presentes en los suelos. Esta simbiosis constituye un recurso biológico para la recuperación de suelos degradados. El objetivo de este estudio fue determinar el efecto de la inoculación con AMF (Glomus spp. sobre el crecimiento de alfalfa (Medicago sativa L. en suelos agrícolas con distintos niveles de cobre (Cu para la recuperación de

颈静脉球内侧壁的临床解剖研究%Applied anatomy of medial wall of the glomus jugulare

Institute of Scientific and Technical Information of China (English)

田广永; 段永畅; 石小田; 于巧莲; 彭志强; 黄美贤; 徐达传

2011-01-01

目的 探讨颈静脉球内侧壁的解剖学特点，为颈静脉球部位的外科手术提供理论指导。方法显微镜下解剖15具经福尔马林固定乳胶灌注的成人头颅标本颈静脉球部位，观察颈静脉球内侧壁部位的结构特点及神经走行关系;在5具干颅骨标本上观察颈静脉球内侧壁的骨性标志。 结果 颈静脉孔内口、颞骨颈静脉突、枕骨颈静脉突、硬脑膜及经该部位穿行的Ⅸ、Ⅹ、Ⅺ颅神经共同构成了颈静脉球内侧壁;在颈静脉球内侧壁自前上往后下做一弧形斜线，斜线的前下位置为神经部，为神经纤维束穿行部位;后上部位为静脉部位，颈静脉球壁与颞骨岩部及硬脑膜紧贴；舌咽神经走行在前上位置，多数有岩下窦的开口将之与迷走神经分隔，中间有条索状的纤维组织分隔。迷走神经和副神经在颈静脉球内侧壁走行关系密切，本组有26侧(86.67％)舌咽神经与迷走神经之间有硬脑膜间隔，4侧(13.33％)硬脑膜间隔不明显。迷走神经和副神经无明显间隔穿人颈静脉球内侧壁，多数迷走神经与副神经容易区分；舌下神经经舌下神经管走行在颈静脉球内侧壁的下方。结论颈静脉孔内口、颞骨岩部的部分骨质、枕骨的部分骨质、后组颅神经、硬脑膜及静脉壁共同组成颈静脉球的内侧壁，了解该部位的解剖学特点能够对颈静脉球部位手术提供理论指导，减少手术并发症。%Objective To study the anatomical features of medial wall of the glomus jugulare to provide the theoretical direction for surgery of the glomus jugulare. Methods Fifteen (30 sides)formalin-fixed adult cadaveric specimens were dissected under the operating microscope, and their structural features of the medial wall of the glomus jugulare and their anastomosis of nerves were observed; and 5 dry skull specimen were also employed to observe the bone landmark of medial wall of the

A phosphate transporter from the mycorrhizal fungus Glomus versiforme.

Science.gov (United States)

Harrison, M J; van Buuren, M L

1995-12-07

Vesicular-arbuscular (VA) mycorrhizal fungi form symbiotic associations with the roots of most terrestrial plants, including many agriculturally important crop species. The fungi colonize the cortex of the root to obtain carbon from their plant host, while assisting the plant with the uptake of phosphate and other mineral nutrients from the soil. This association is beneficial to the plant, because phosphate is essential for plant growth and development, especially during growth under nutrient-limiting conditions. Molecular genetic studies of these fungi and their interaction with plants have been limited owing to the obligate symbiotic nature of the VA fungi, so the molecular mechanisms underlying fungal-mediated uptake and translocation of phosphate from the soil to the plant remain unknown. Here we begin to investigate this process by identifying a complementary DNA that encodes a transmembrane phosphate transporter (GvPT) from Glomus versiforme, a VA mycorrhizal fungus. The function of the protein encoded by GvPT was confirmed by complementation of a yeast phosphate transport mutant. Expression of GvPT was localized to the external hyphae of G. versiforme during mycorrhizal associations, these being the initial site of phosphate uptake from the soil.

The mycorrhizal fungus (¤Glomus intraradices¤) affects microbial activity in the rhizosphere of pea plants (¤Pisum sativum¤)

DEFF Research Database (Denmark)

Wamberg, C.; Christensen, S.; Jakobsen, I.

2003-01-01

Pea plants were grown in gamma-irradiated soil in pots with and without addition of the AM fungus Glomus intraradices at sufficient N and limiting P. Depending on the growth phase of the plant presence of AM had negative or positive effect on rhizosphere activity. Before flowering during nutrient...... in the rhizosphere community during plant growth also supported by changes in the bacteria (DGGE). (C) 2003 Elsevier Ltd. All rights reserved....

The Arbuscular Mycorrhizal Fungus Funneliformis mosseae Alters Bacterial Communities in Subtropical Forest Soils during Litter Decomposition

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Heng Gui

2017-06-01

Full Text Available Bacterial communities and arbuscular mycorrhizal fungi (AMF co-occur in the soil, however, the interaction between these two groups during litter decomposition remains largely unexplored. In order to investigate the effect of AMF on soil bacterial communities, we designed dual compartment microcosms, where AMF (Funneliformis mosseae was allowed access (AM to, or excluded (NM from, a compartment containing forest soil and litterbags. Soil samples from this compartment were analyzed at 0, 90, 120, 150, and 180 days. For each sample, Illumina sequencing was used to assess any changes in the soil bacterial communities. We found that most of the obtained operational taxonomic units (OTUs from both treatments belonged to the phylum of Proteobacteria, Acidobacteria, and Actinobacteria. The community composition of bacteria at phylum and class levels was slightly influenced by both time and AMF. In addition, time and AMF significantly affected bacterial genera (e.g., Candidatus Solibacter, Dyella, Phenylobacterium involved in litter decomposition. Opposite to the bacterial community composition, we found that overall soil bacterial OTU richness and diversity are relatively stable and were not significantly influenced by either time or AMF inoculation. OTU richness at phylum and class levels also showed consistent results with overall bacterial OTU richness. Our study provides new insight into the influence of AMF on soil bacterial communities at the genus level.

The Effect Different Fertilizers, on Germination, Yield, of Vicia vilosa Roth

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R Kamaei

2015-09-01

Full Text Available In order to study the interaction of germination, yield of Vicia vilosa Roth to use of biological fertilizer, chemical, and manure, an experiment was conducted as a randomized complete block design with three replications at Research greenhouse, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in 2013-2014 growing season. The experimental treatments was included three kinds of bio fertilizers and their integration with each other and vermicompost and chemical fertilizer as following : 1- mycorhhizaarbuscular species Glomus mosseae+vermicompost2- mycorhhiza+Nitrocsin (included bacteries Azospirillum sp. and Azotobacter sp. 3- mycorhhiza arbuscular+ Rhizobium (Rhizobium sp. 4-mycorhhiza arbuscular + Chemical fertilizer NPK 5- mycorhhizaarbuscular (Glomus moseae 6-control. The results showed that, although the treatments has not significant effects on height of stem , it has significant effects on characteristics of root length colonization percent, number the root node, Root dry weight, soggy yield, yield dry and protein Percent. The results showed that the highest percent of root length colonization(76 percent, number the root node (20, Root dry weight (.94 g, soggy yield (1894.5 g m-2, yield dry (473.63 g m-2 and protein Percent (27.33 percent was gained in integrated mycorhhiza and nitrocsine treatment. On the basis of results, the integration of mycrhhoriza and biological rhizobium is suggested as the best fertilizer treatment for Vicia vilosa Roth.

Preferential colonization of Solanum tuberosum L. roots by the fungus Glomus intraradices in arable soil of a potato farming area.

Science.gov (United States)

Cesaro, Patrizia; van Tuinen, Diederik; Copetta, Andrea; Chatagnier, Odile; Berta, Graziella; Gianinazzi, Silvio; Lingua, Guido

2008-09-01

The symbiosis between plant roots and arbuscular mycorrhizal (AM) fungi has been shown to affect both the diversity and productivity of agricultural communities. In this study, we characterized the AM fungal communities of Solanum tuberosum L. (potato) roots and of the bulk soil in two nearby areas of northern Italy, in order to verify if land use practices had selected any particular AM fungus with specificity to potato plants. The AM fungal large-subunit (LSU) rRNA genes were subjected to nested PCR, cloning, sequencing, and phylogenetic analyses. One hundred eighty-three LSU rRNA sequences were analyzed, and eight monophyletic ribotypes, belonging to Glomus groups A and B, were identified. AM fungal communities differed between bulk soil and potato roots, as one AM fungal ribotype, corresponding to Glomus intraradices, was much more frequent in potato roots than in soils (accounting for more than 90% of sequences from potato samples and less than 10% of sequences from soil samples). A semiquantitative heminested PCR with specific primers was used to confirm and quantify the AM fungal abundance observed by cloning. Overall results concerning the biodiversity of AM fungal communities in roots and in bulk soils from the two studied areas suggested that potato roots were preferentially colonized by one AM fungal species, G. intraradices.

Crescimento, parâmetros biofísicos e aspectos anatômicos de plantas jovens de seringueira inoculadas com fungo micorrízico arbuscular Glomus clarum Growth, biophysical parameters and anatomical aspects of young rubber tree plants inoculated with arbuscular mycorrhizal fungi Glomus clarum

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Patrícia Fabian de Araújo Diniz

2010-03-01

Full Text Available Fungos micorrízicos são reconhecidamente benéficos quando em associação às plantas por favorecerem seu crescimento e desenvolvimento. Apesar de pouco comum para a seringueira, a inoculação artificial de fungos micorrízicos arbusculares (FMAs tem se mostrado uma alternativa para a redução no uso de fertilizantes e pesticidas nas culturas, bem como para a formação de mudas, visando obtenção de porta-enxertos precoces e bem nutridos. O estudo objetivou avaliar o efeito da inoculação do FMA Glomus clarum no crescimento e características biofísicas e anatômicas de plantas jovens de seringueira. Os tratamentos consistiram de plantas inoculadas com o fungo Glomus clarum adubadas com 50 ppm de fósforo (mic+50P, plantas não inoculadas adubadas com 50 ppm de fósforo (s/mic+50P e plantas não inoculadas adubadas com 500 ppm de fósforo (s/mic+500P. Constatou-se que as plantas micorrizadas apresentaram altura e diâmetro dos caules, matéria seca da parte aérea, densidade estomática e área foliar, semelhantes às plantas s/mic+500P. Maior acúmulo de matéria seca de raiz, maior taxa de transpiração, menor resistência estomática e menor temperatura foliar foram observadas para as plantas micorrizadas. As análises anatômicas das raízes evidenciam a ocorrência de alterações no tecido vascular, com aumento no número de pólos de xilema das raízes das plantas micorrizadas.Mycorrhizal fungi are beneficial when associated with plants because they favor growth and develop. Although infrequent, artificial inoculation of arbuscular mycorrhizal fungi (AMF has become an alternative to reduce the use of fertilizers and pesticides in crops, as well as for the formation of seedlings, to obtain precocious and well fed rootstocks. The objective of the study was to evaluate the effect of inoculation of AMF Glomus clarum on growth and biophysical and anatomical characteristics of young rubber trees. The treatments consist of plants

Plant growth and metal distribution in tissues of Prosopis juliflora-velutina grown on chromium contaminated soil in the presence of Glomus deserticola.

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Arias, Jack A; Peralta-Videa, Jose R; Ellzey, Joanne T; Viveros, Marian N; Ren, Minghua; Mokgalaka-Matlala, Ntebogeng S; Castillo-Michel, Hiram; Gardea-Torresdey, Jorge L

2010-10-01

Arbuscular mycorrhizal fungi have been known to increase metal uptake in plants. In this study, mesquite (Prosopis juliflora-velutina) inoculated with Glomus deserticola or amended with EDTA were grown for 30 days in soil containing Cr(III) or Cr(VI) at 0, 40, 80, and 160 mg kg(-1). Total amylase activity (TAA) was monitored as a stress indicator. Element concentrations and distribution in tissue were determined using ICP-OES, electron scanning microprobe, and TEM. Inoculated Cr(VI) treated plants had 21% and 30% more Cr than uninoculated and EDTA treated roots, respectively, at 80 mg Cr kg(-1) treatment. In the case of Cr(III), EDTA produced the highest Cr accumulation in roots. TAA was higher in inoculated plants grown with Cr(III) at 80 and 160 mg kg(-1) and Cr(VI) at 40 and 160 mg kg(-1). The X-ray mapping showed higher metal concentrations in the vascular system of inoculated plants and the TEM micrographs demonstrated the presence of G. deserticola in roots.

Long-term effectiveness and safety of stereotactic gamma knife surgery as a primary sole treatment in the management of glomus jagulare tumor.

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Hafez, Raef F A; Morgan, Magad S; Fahmy, Osama M; Hassan, Hamdy T

2018-05-01

This study aims to report and confirm long-term effectiveness and safety of stereotactic Gamma Knife Surgery as a primary sole treatment in the management of 40 glomus jagulare tumors patients. Retrospective analysis of clinical and radiological outcomes of 40 GJTs consecutive patients treated with GKS as primary sole treatment at International Medical Center (IMC), Cairo-Egypt from the beginning of 2005 till the end of 2014,with mean follow-up period of 84 months (range 36-156 months), mean tumor volume was 6.5 cc, and mean peripheral radiation dose of 15 Gy, to mean isodose curve of 38%. The most common neurological deficit at initial evaluation was bulbar symptoms in 24 patients, followed by pulsatile tinnitus in 22, deterioration of hearing in 20 patients. The overall clinical control achieved in 92.5% of patients, while actuarial tumor size control rate post- GKS was 97.5% at 3 years, 97% at 5 years and 92% at 10 years of follow-up period. Gamma knife surgery could be used effectively and safely as a primary sole treatment tool in the management of glomus jugulare tumors. Copyright © 2018 Elsevier B.V. All rights reserved.

Application of Glomus sp. and Pseudomonas diminuta Reduce the Use of Chemical Fertilizers in Production of Potato Grown on Different Soil Types

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Nurbaity, A.; Sofyan, E. T.; Hamdani, J. S.

2016-08-01

The use of high chemical fertilizer rates in potato production has been applied on the farm in Indonesia. Application of biofertilizer consists of arbuscular mycorrhizal fungi has been tested to reduce the use of NPK rates in production of potato and to determine whether different soil types will have different response to this biofertilizer. A greenhouse experiment was conducted using mixtures of spores of Glomus sp. and inoculant of mycorrhizal helper bacteria Pseudomonas diminuta, applied at different rates of NPK fertilizer (0, 25, 50, 75 and 100% of recommended rates) and different soil types (Andisols and Inceptisols). Results of experiment showed that application of Glomus sp. and P. diminuta reduced the use of NPK up to 50%, where the growth (plant height and tuber number), N,P,K uptake and tuber yields of potato had similar effect to the highest recommendation rate of NPK fertilizer. Inceptisols in general had better response to the biofertiliser compared to Andisols. Findings from this experiment confirmed the evidences that biofertilizer could reduce the use of chemical fertilizer, and the widely distributed soil in Indonesia such as Inceptisols, is potential to be used as a medium for potato production.

Efeito de Glomus etunicatum e fósforo no crescimento inicial de espécies arbóreas em semeadura direta Effects of Glomus etunicatum and phosphorus on initial growth of woody species at direct seeding

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Waldo Wilfredo Flores-Aylas

2003-02-01

Full Text Available O objetivo deste trabalho foi avaliar os efeitos da disponibilidade de P no solo, da micorriza formada por Glomus etunicatum e de Mycoform, um estimulante desta última, no crescimento e competição inicial de seis espécies arbóreas semeadas diretamente. O trabalho foi realizado em casa de vegetação com as espécies Senna macranthera (fedegoso, Guazuma ulmifolia (mutamba, Senna multijuga (cássia-verrugosa, Solanum granuloso-leprosum (gravitinga, Schinus terebenthifolius (aroeira e Trema micrantha (trema, em solo com níveis de P na solução considerados muito baixo, baixo e alto, com inoculação ou não do fungo micorrízico arbuscular G. etunicatum, além do tratamento G. etunicatum + Mycoform. O crescimento das mudas respondeu à inoculação em P muito baixo e baixo. As mudas apresentaram moderada dependência das micorrizas, não respondendo ao G. etunicatum em P alto. Gravitinga morreu em P muito baixo, mas foi dominante com P baixo e alto. Fedegoso foi dominante com P muito baixo, mostrando-se adaptado à baixa fertilidade. G. etunicatum influenciou a dominância das espécies, auxiliando as menos competitivas e gerando maior equilíbrio. Mycoform influenciou pouco o crescimento, nutrição e competição. O crescimento de espécies pioneiras semeadas diretamente é favorecido pela elevação do P e pelas micorrizas, as quais também favorecem o equilíbrio entre espécies.The objective of this work was to evaluate the effects of soil P availability, mycorrhiza and a mycorrhiza stimulatory product (Mycoform upon growth and initial competition of six sown woody species, in the greenhouse. The species Senna macranthera, Guazuma ulmifolia, Senna multijuga, Solanum granuloso-leprosum, Schinus terebenthifolius and Trema micrantha were sown together in a soil with very low, low and high levels of P in soil solution combined with inoculation treatments of the arbuscular mycorrhizal fungus Glomus etunicatum, G. etunicatum + Mycoform and a

Status and phosphorus solubilization potential of bacteria and arbuscular mycorrhizal fungi isolated from various locations of Khyber Pakhtunkhwa province

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Wahid, F.; Sharif, M.; Khan, M.

2016-01-01

The soils of Pakistan are alkaline calcareous in nature and its high pH makes phosphorus (P) unavailable for plants uptake. Chemical sources of P fertilizers are a costly and detrimental practice. Therefore, investigations were conducted to determine the native status of phosphate solubilizing bacteria (PSB) and arbuscular mycorrhizal fungi (AMF) in three different zones of Khyber Pakhtunkhwa province of Pakistan. In order to select the efficient PSB strains for solubility enhancement of P from rock phosphate (RP), rhizosphere soil samples were collected from irrigated and rainfed fields of maize, sorghum, pastures and vegetables. Population density of PSB ranged from 1.7*107 to 2.7*108 CFU g-1 rhizosphere soil. The bacterial strains Coccus, Streptoccocus and Bacillus sp. were identified on the basis of their microscopic, phenotypic and morphological characters. Most of the AM fungal spores identified were belonging to Glomus mosseae and Glomus intradices. A range of 02-35 spores per 20 g air dried soil were recorded. The PSB strains such as Coccus DIM7, Streptococcus PIM6 and Bacillus sp. PIS7 solubilized more P from RP than any other strain in both of the liquid and solid medium. Results show that areas under investigations are rich in P solubilizing micro flora providing a rich source for inoculum production. Moreover, the PSB strains have the capability to solubilize P from RP that can be used as biofertilizers for optimum crop production. (author)

Role of VAM on growth and phosphorus nutrition of maize with low soluble phosphate fertilization

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Amitava Rakshit

2010-01-01

Full Text Available The effect of vesicular arbuscular mycorrhizal (VAM infection on growth and P nutrition in Maize (Zea mays, cv.DDH hybrid were assessed in Oxisol pot experiment. Maize was grown inoculated with spores of VAM fungi Glomus mosseae or non-inoculated. Low soluble ferrous phosphate (FePO4.4H2O was added to the mycorrhized and non-micrrohized maized. The dry weight of mycorrhized plants with added phosphate (P were higher than in mycorrhized plants without added P or non-mycorrhized plants with added P. The amount of P in the soil samples from pots with mycorrhizal plants fertilized with P was evidently smaller than those in samples also fertilized non-mycorrhizal plants. The percentage of P was higher in tissues of fertilized mycorrhial plants than in those mycorrihzed plants without or nonmycorrhized plants with added low-soluble P. These results indicated that plants in VAM symbiosis mobilize P better from low-soluble P than non-mycorrhized plants.

Role of VAM on growth and phosphorus nutrition of maize with low soluble phosphate fertilization

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Rakshit Amitava

2010-03-01

Full Text Available The effect of vesicular arbuscular mycorrhizal (VAM infection on growth and P nutrition in Maize (Zea mays, cv.DDH hybrid were assessed in Oxisol pot experiment. Maize was grown inoculated with spores of VAM fungi Glomus mosseae or non-inoculated. Low soluble ferrous phosphate (FePO4.4H2O was added to the mycorrhized and non-micrrohized maized. The dry weight of mycorrhized plants with added phosphate (P were higher than in mycorrhized plants without added P or non-mycorrhized plants with added P. The amount of P in the soil samples from pots with mycorrhizal plants fertilized with P was evidently smaller than those in samples also fertilized non-mycorrhizal plants. The percentage of P was higher in tissues of fertilized mycorrhial plants than in those mycorrihzed plants without or nonmycorrhized plants with added low-soluble P. These results indicated that plants in VAM symbiosis mobilize P better from low-soluble P than non-mycorrhized plants.

Arbuscular mycorrhiza of plants from the Mountain Botanical Garden in Zakopane

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Szymon Zubek

2014-08-01

Full Text Available The mycorrhizal status of 77 plant species collected from the Mountain Botanical Garden of the Polish Academy of Sciences in Zakopane (southern Poland was surveyed. These plants include rare, endemic and threatened species in the Tatra Mts. (the Western Carpathians and are maintained in the botanical garden in order to develop effective methods of protection and cultivation. Plants belonging to Brassicaceae, Caryophyllaceae, Dryopteridaceae, Juncaceae, Polygonaceae, Rubiaceae and Woodsiaceae families were nonmycorrhizal. 41 species formed AM symbiosis. Spores of nine AMF spccies (Glomeromycota, including Archaeospora trappei, Glomus aggregatum, G. claroideum, G. constrictum, G. deserticola, G. geosponrum, G. microcarpum, G. mosseae and G.rubiforme were isolated for the first time from this region of Poland. In addition, the occurrence of the fine endophyte, G. tenue was detected in roots of 18 species from the study area, although formation of arbuscules by this fungus was observed rarely. AM fungi were sporadically accompanied by dark septate endophytes (DSE. 70% of nonmycorrhizal plant sepcies were devoid of DSE.

Actinobacteria Associated With Arbuscular Mycorrhizal Funneliformis mosseae Spores, Taxonomic Characterization and Their Beneficial Traits to Plants: Evidence Obtained From Mung Bean (Vigna radiata) and Thai Jasmine Rice (Oryza sativa)

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Lasudee, Krisana; Tokuyama, Shinji; Lumyong, Saisamorn; Pathom-aree, Wasu

2018-01-01

In this study, we report on the isolation of actinobacteria obtained from spores of Funneliformis mosseae and provide evidence for their potential in agricultural uses as plant growth promoters in vitro and in vivo. Actinobacteria were isolated from spores of F. mosseae using the dilution plate technique and media designed for the selective isolation of members of specific actinobacterial taxa. Six strains namely 48, S1, S3, S4, S4-1 and SP, were isolated and identified based on16S rRNA gene sequences. Phylogenetic analysis showed that isolate SP belonged to the genus Pseudonocardia with P. nantongensis KLBMP 1282T as its closest neighbor. The remaining isolates belonged to the genus Streptomyces. Two isolates, 48 and S3 were most closely related to S. thermocarboxydus DSM 44293T. Isolates S4 and S4-1 shared the highest 16S RNA gene similarity with S. pilosus NBRC 127772T. Isolate S1 showed its closest relationship with the type strain of S. spinoverrucosus NBRC14228T. The ability of these isolates to produce indole-3-acetic acid (IAA), siderophores and the ability to solubilize phosphate in vitro were examined. All isolates produced siderophores, four isolates produced IAA and two isolates solubilized inorganic phosphate at varying levels. S. thermocarboxydus isolate S3 showed the highest IAA production with high activities of phosphate solubilization and siderophore production. The inoculation of mung beans (Vigna radiata) with this strain resulted in a significant increase in fresh weight, root length and total length as an effect of IAA production. In an experiment with rice (Oryza sativa), S. thermocarboxydus isolate S3 promoted the growth of rice plants grown in low nutritional soil under induced drought stress. This report supports the view that the inoculation of rice with plant growth promoting actinobacteria mitigates some adverse effects of low nutrient and drought stress on rice. PMID:29942292

The cultivation bias: different communities of arbuscular mycorrhizal fungi detected in roots from the field, from bait plants transplanted to the field, and from a greenhouse trap experiment.

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Sýkorová, Zuzana; Ineichen, Kurt; Wiemken, Andres; Redecker, Dirk

2007-12-01

The community composition of arbuscular mycorrhizal fungi (AMF) was investigated in roots of four different plant species (Inula salicina, Medicago sativa, Origanum vulgare, and Bromus erectus) sampled in (1) a plant species-rich calcareous grassland, (2) a bait plant bioassay conducted directly in that grassland, and (3) a greenhouse trap experiment using soil and a transplanted whole plant from that grassland as inoculum. Roots were analyzed by AMF-specific nested polymerase chain reaction, restriction fragment length polymorphism screening, and sequence analyses of rDNA small subunit and internal transcribed spacer regions. The AMF sequences were analyzed phylogenetically and used to define monophyletic phylotypes. Overall, 16 phylotypes from several lineages of AMF were detected. The community composition was strongly influenced by the experimental approach, with additional influence of cultivation duration, substrate, and host plant species in some experiments. Some fungal phylotypes, e.g., GLOM-A3 (Glomus mosseae) and several members of Glomus group B, appeared predominantly in the greenhouse experiment or in bait plants. Thus, these phylotypes can be considered r strategists, rapidly colonizing uncolonized ruderal habitats in early successional stages of the fungal community. In the greenhouse experiment, for instance, G. mosseae was abundant after 3 months, but could not be detected anymore after 10 months. In contrast, other phylotypes as GLOM-A17 (G. badium) and GLOM-A16 were detected almost exclusively in roots sampled from plants naturally growing in the grassland or from bait plants exposed in the field, indicating that they preferentially occur in late successional stages of fungal communities and thus represent the K strategy. The only phylotype found with high frequency in all three experimental approaches was GLOM A-1 (G. intraradices), which is known to be a generalist. These results indicate that, in greenhouse trap experiments, it is difficult

Phyto-Extraction of Nickel by Linum usitatissimum in Association with Glomus intraradices.

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Amna; Masood, Sajid; Syed, Jabir Hussain; Munis, Muhammad Farooq Hussain; Chaudhary, Hassan Javed

2015-01-01

Plants show enhanced phytoremediation of heavy metal contaminated soils particularly in response to fungal inoculation. Present study was conducted to find out the influence of Nickel (Ni) toxicity on plant biomass, growth, chlorophyll content, proline production and metal accumulation by L. usitatissimum (flax) in the presence of Glomus intraradices. Flax seedlings of both inoculated with G. intraradices and non-inoculated were exposed to different concentrations i.e., 250, 350 and 500 ppm of Ni at different time intervals. Analysis of physiological parameters revealed that Ni depressed the growth and photosynthetic activity of plants. However, the inoculation of plants with arbuscular mycorrhizae (G. intraradices) partially helped in the alleviation of Ni toxicity as indicated by improved plant growth under Ni stress. Ni uptake of non- mycorrhizal flax plants was increased by 98% as compared to control conditions whereas inoculated plants showed 19% more uptake when compared with the non-inoculated plants. Mycorrhizal plants exhibited increasing capacity to remediate contaminated soils along with improved growth. Thus, AM assisted phytoremediation helps in the accumulation of Ni in plants to reclaim Ni toxic soils. Based on our findings, it can be concluded that the role of flax plants and mycorrhizal fungi is extremely important in phytoremediation.

Radiation therapy for glomus tumors of the temporal bone

International Nuclear Information System (INIS)

Dall'Igna, Celso; Antunes, Marcelo B.

2005-01-01

The treatment of glomic tumors has been controversial since its first description. It can be done with surgery, radiotherapy or just expectation. Aim: the objective of this paper was to evaluate the effectiveness and complications of radiotherapy.Study Design: clinical with transversal cohort. Material and method: it was made a retrospective review in the charts of the patients with glomus jugular tumors treated with radiotherapy. Disease control was determined by (1) no progression of symptoms or cranial nerve dysfunction or (2) no progression of the lesion in radiological follow-up. It was also evaluated the follow-up period and the sequelae of the treatment. Results: twelve patients were included, 8 of then women. The follow-up period was from 3 to 35 years, with a media of 11,6 years. The main symptoms were: hearing loss, pulsate tinnitus, dizziness and vertigo. The signs were pulsate retrotympanic mass, facial palsy and cofosis. The tumors were staged using Fischs classification. The radiotherapy was performed with linear accelerator with dose ranging from 4500-5500 in 4-6 weeks. In the follow-up period were possible to identify sequelaes like dermatitis, meatal stenosis, cofosis and facial palsy. Discussion: the signs and symptoms were the same found in the medical literature. The type and dosages of the radiotherapy were also the same of others reports. All patients had improvement of the symptoms and only one was not considered as having disease controlled. Complications were, in general, minor complications, with exception of the cofosis and facial palsy. Conclusion: radiotherapy is a viable alternative to treatment of these tumors because their good response and low level of complications. It should be considered specially in advanced tumors where a surgical procedure could bring a high level of morbidity. (author)

Grain yield and arsenic uptake of upland rice inoculated with arbuscular mycorrhizal fungi in As-spiked soils.

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Wu, Fuyong; Hu, Junli; Wu, Shengchun; Wong, Ming Hung

2015-06-01

A pot trial was conducted to investigate the effects of three arbuscular mycorrhizal (AM) fungi species, including Glomus geosporum BGC HUN02C, G. versiforme BGC GD01B, and G. mosseae BGC GD01A, on grain yield and arsenic (As) uptake of upland rice (Zhonghan 221) in As-spiked soils. Moderate levels of AM colonization (24.1-63.1 %) were recorded in the roots of upland rice, and up to 70 mg kg(-1) As in soils did not seem to inhibit mycorrhizal colonization. Positive mycorrhizal growth effects in grain, husk, straw, and root of the upland rice, especially under high level (70 mg kg(-1)) of As in soils, were apparent. Although the effects varied among species of AM fungi, inoculation of AM fungi apparently enhanced grain yield of upland rice without increasing grain As concentrations in As-spiked soils, indicating that AM fungi could alleviate adverse effects on the upland rice caused by As in soils. The present results also show that mycorrhizal inoculation significantly (p rice production when growing in As-contaminated soils.

Arbuscular mycorrhizal fungal communities in the rhizosphere of a continuous cropping soybean system at the seedling stage.

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Cui, Jiaqi; Bai, Li; Liu, Xiaorui; Jie, Weiguang; Cai, Baiyan

Arbuscular mycorrhizae (AM) fungi play a crucial role in the growth of soybean; however, the planting system employed is thought to have an effect on AM fungal communities in the rhizosphere. This study was performed to explore the influence of continuous soybean cropping on the diversity of Arbuscular mycorrhizal (AM) fungi, and to identify the dominant AM fungus during the seedling stage. Three soybean cultivars were planted under two and three years continuous cropping, respectively. The diversity of AM fungi in the rhizosphere soil at the seedling stage was subsequently analyzed using polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). The results showed that an increase in cropping years improved the colonization rate of AM in all three soybean cultivars. Moreover, the dominant species were found to be Funneliformis mosseae and Glomus species. The results of cluster analysis further confirmed that the number of years of continuous cropping significantly affected the composition of rhizospheric AM fungal communities in different soybean cultivars. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Effect of nitrate supply and mycorrhizal inoculation on characteristics of tobacco root plasma membrane vesicles.

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Moche, Martin; Stremlau, Stefanie; Hecht, Lars; Göbel, Cornelia; Feussner, Ivo; Stöhr, Christine

2010-01-01

Plant plasma membrane (pm) vesicles from mycorrhizal tobacco (Nicotiana tabacum cv. Samsun) roots were isolated with negligible fungal contamination by the aqueous two-phase partitioning technique as proven by fatty acid analysis. Palmitvaccenic acid became apparent as an appropriate indicator for fungal membranes in root pm preparations. The pm vesicles had a low specific activity of the vanadate-sensitive ATPase and probably originated from non-infected root cells. In a phosphate-limited tobacco culture system, root colonisation by the vesicular arbuscular mycorrhizal fungus, Glomus mosseae, is inhibited by external nitrate in a dose-dependent way. However, detrimental high concentrations of 25 mM nitrate lead to the highest colonisation rate observed, indicating that the defence system of the plant is impaired. Nitric oxide formation by the pm-bound nitrite:NO reductase increased in parallel with external nitrate supply in mycorrhizal roots in comparison to the control plants, but decreased under excess nitrate. Mycorrhizal pm vesicles had roughly a twofold higher specific activity as the non-infected control plants when supplied with 10-15 mM nitrate.

Enhanced phytoremediation of soils contaminated with PAHs by arbuscular mycorrhiza and rhizobium.

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Ren, Cheng-Gang; Kong, Cun-Cui; Bian, Bian; Liu, Wei; Li, Yan; Luo, Yong-Ming; Xie, Zhi-Hong

2017-09-02

Greenhouse experiment was conducted to evaluate the potential effectiveness of a legume (Sesbania cannabina), arbuscular mycorrhizal fungi (AMF) (Glomus mosseae), and rhizobia (Ensifer sp.) symbiosis for remediation of Polycyclic aromatic hydrocarbons (PAHs) in spiked soil. AMF and rhizobia had a beneficial impact on each other in the triple symbiosis. AMF and/or rhizobia significantly increased plant biomass and PAHs accumulation in plants. The highest PAHs dissipation was observed in plant + AMF + rhizobia treated soil, in which >97 and 85-87% of phenanthrene and pyrene, respectively, had been degraded, whereas 81-85 and 72-75% had been degraded in plant-treated soil. During the experiment, a relatively large amount of water-soluble phenolic compounds was detected in soils of AMF and/or rhizobia treatment. It matches well with the high microbial activity and soil enzymes activity. These results suggest that the mutual interactions in the triple symbiosis enhanced PAHs degradation via stimulating both microbial development and soil enzyme activity. The mutual interactions between rhizobia and AMF help to improve phytoremediation efficiency of PAHs by S. cannabina.

[Effect of Glomus versiforme and Trichoderma harzianum on growth and quality of Salvia miltiorrhiza].

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Wang, Xue; Chen, Mei-Lan; Yang, Guang; Li, Xiao-Ming; Li, Peng-Ying; Chen, Min

2014-05-01

The present study aimed to investigate the effect of Glomus versiforme and Trichodema harzianum on the growth and quality of Salvia miltiorrhiza continuous cropping under field conditions. The field plot experiment was conducted, these active components in the plant were analyzed by HPLC, the root diseases incidence rate of S. miltiorrhiza determined by observation and counting, and relative parameters were measured. The data was statistically processed. The result showed that inoculation of G. versiforme and combined inoculation of G. versiforme with T. harzianum significantly decreased the root diseases incidence rate of S. miltiorrhiza, and combined inoculation of G. versiforme with T. harzianum was better than other treatments. All treatments improved accumulation of active ingredients in root. Inoculation of G. versiforme and combined inoculation of G. versiforme with T. harzianum significantly increased the content of salvianolic acid B and cryptotanshinone of root (P harzianum and combined inoculation of G. versiforme with T. harzianum significantly enhanced the content of tanshinone I and tanshinone II(A) of the root (P harzianum can effectively reduce the root diseases incidence of continuous cropping S. miltiorrhiza, and improve the quality of S. miltiorrhiza.

Positive feedback between mycorrhizal fungi and plants influences plant invasion success and resistance to invasion.

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Zhang, Qian; Yang, Ruyi; Tang, Jianjun; Yang, Haishui; Hu, Shuijin; Chen, Xin

2010-08-24

Negative or positive feedback between arbuscular mycorrhizal fungi (AMF) and host plants can contribute to plant species interactions, but how this feedback affects plant invasion or resistance to invasion is not well known. Here we tested how alterations in AMF community induced by an invasive plant species generate feedback to the invasive plant itself and affect subsequent interactions between the invasive species and its native neighbors. We first examined the effects of the invasive forb Solidago canadensis L. on AMF communities comprising five different AMF species. We then examined the effects of the altered AMF community on mutualisms formed with the native legume forb species Kummerowia striata (Thunb.) Schindl. and on the interaction between the invasive and native plants. The host preferences of the five AMF were also assessed to test whether the AMF form preferred mutualistic relations with the invasive and/or the native species. We found that S. canadensis altered AMF spore composition by increasing one AMF species (Glomus geosporum) while reducing Glomus mosseae, which is the dominant species in the field. The host preference test showed that S. canadensis had promoted the abundance of AMF species (G. geosporum) that most promoted its own growth. As a consequence, the altered AMF community enhanced the competitiveness of invasive S. canadensis at the expense of K. striata. Our results demonstrate that the invasive S. canadensis alters soil AMF community composition because of fungal-host preference. This change in the composition of the AMF community generates positive feedback to the invasive S. canadensis itself and decreases AM associations with native K. striata, thereby making the native K. striata less dominant.

Positive feedback between mycorrhizal fungi and plants influences plant invasion success and resistance to invasion.

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Qian Zhang

2010-08-01

Full Text Available Negative or positive feedback between arbuscular mycorrhizal fungi (AMF and host plants can contribute to plant species interactions, but how this feedback affects plant invasion or resistance to invasion is not well known. Here we tested how alterations in AMF community induced by an invasive plant species generate feedback to the invasive plant itself and affect subsequent interactions between the invasive species and its native neighbors. We first examined the effects of the invasive forb Solidago canadensis L. on AMF communities comprising five different AMF species. We then examined the effects of the altered AMF community on mutualisms formed with the native legume forb species Kummerowia striata (Thunb. Schindl. and on the interaction between the invasive and native plants. The host preferences of the five AMF were also assessed to test whether the AMF form preferred mutualistic relations with the invasive and/or the native species. We found that S. canadensis altered AMF spore composition by increasing one AMF species (Glomus geosporum while reducing Glomus mosseae, which is the dominant species in the field. The host preference test showed that S. canadensis had promoted the abundance of AMF species (G. geosporum that most promoted its own growth. As a consequence, the altered AMF community enhanced the competitiveness of invasive S. canadensis at the expense of K. striata. Our results demonstrate that the invasive S. canadensis alters soil AMF community composition because of fungal-host preference. This change in the composition of the AMF community generates positive feedback to the invasive S. canadensis itself and decreases AM associations with native K. striata, thereby making the native K. striata less dominant.

Effects of salt stress and mycorrhiza fungi on morpho-physiological characteristics of sweet corn

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seyed Abdolreza kazemeini

2017-06-01

Full Text Available In order to investigate the interaction of mycorrhizal fungi and salinity on growth and physiological characteristics of sweet corn, a greenhouse experiment was conducted at College of Agriculture, Shiraz University, in 2014. The experimental design was factorial based on Completely Randomized Design in three replications. Treatments included salinity at four levels (0.4 (control, 4, 7, 10 dS m-1, and the fungi at three levels (no fungi (control, Glomus mosseae, Glomus intraradices. Results indicated that at flowering stage, with increasing salinity levels, leaf chlorophyll a, b and a+b content and carotenoid decreased at a rate of 18.9, 52.4, 33.1, and 34.5 respectively. Application of mycorrhiza under salinity, partially offset the negative impacts and increased tolerance of maize to NaCl by enhancing SOD and CAT activities, chlorophyll contents, carotenoid and K concentrations in leaves, plant height, leaf area, and total dry weight at flowering stage significantly, compared to control. The Na/K ratio at salinity level of 10 dS m-1 in treatments inoculated with GIN and GM fungi decreased by 39.69 and 40.45 percentage, respectively. Increases plant height, leaf area, total dry weight, concentrations of chlorophyll a, b, chlorophyll a+b and carotenoid and K, the activity of antioxidant enzymes compared with the control. Moreover, GIN type fungi had a greater advantage over GM and reduced the negative effects of salinity. Results indicated that application of mycorrhiza alleviated the adverse effect of salinity stress and improve the sweet corn dry weight up to 38 percentage at salinity level of 10 dS m-1.

Chitinase activities, scab resistance, mycorrhization rates and biomass of own-rooted and grafted transgenic apple

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Tina Schäfer

2012-01-01

Full Text Available This study investigated the impact of constitutively expressed Trichoderma atroviride genes encoding exochitinase nag70 or endochitinase ech42 in transgenic lines of the apple cultivar Pinova on the symbiosis with arbuscular mycorrhizal fungi (AMF. We compared the exo- and endochitinase activities of leaves and roots from non-transgenic Pinova and the transgenic lines T386 and T389. Local and systemic effects were examined using own-rooted trees and trees grafted onto rootstock M9. Scab susceptibility was also assessed in own-rooted and grafted trees. AMF root colonization was assessed microscopically in the roots of apple trees cultivated in pots with artificial substrate and inoculated with the AMF Glomus intraradices and Glomus mosseae. Own-rooted transgenic lines had significantly higher chitinase activities in their leaves and roots compared to non-transgenic Pinova. Both of the own-rooted transgenic lines showed significantly fewer symptoms of scab infection as well as significantly lower root colonization by AMF. Biomass production was significantly reduced in both own-rooted transgenic lines. Rootstock M9 influenced chitinase activities in the leaves of grafted scions. When grafted onto M9, the leaf chitinase activities of non-transgenic Pinova (M9/Pinova and transgenic lines (M9/T386 and M9/T389 were not as different as when grown on their own roots. M9/T386 and M9/T389 were only temporarily less infected by scab than M9/Pinova. M9/T386 and M9/T389 did not differ significantly from M9/Pinova in their root chitinase activities, AMF root colonization and biomass.

Interaction of Vesicular-arbuscular Mycorrhizal Fungi and Phosphorus with Meloidogyne incognita on Tomato.

Science.gov (United States)

Cason, K M; Hussey, R S; Roncadori, R W

1983-07-01

The influence of two vesicular-arbuscular mycorrhizal fungi and phosphorus (P) nutrition on penetration, development, and reproduction by Meloidogyne incognita on Walter tomato was studied in the greenhouse. Inoculation with either Gigaspora margarita or Glomus mosseae 2 wk prior to nematode inoculation did not alter infection by M. incognita compared with nonmycorrhizal plants, regardless of soil P level (either 3 mug [low P] or 30 mug [high P] available P/g soil). At a given soil P level, nematode penetration and reproduction did not differ in mycorrhizal and nonmycorrhizal plants. However, plants grown in high P soil had greater root weights, increased nematode penetration and egg production per plant, and decreased colonization by mycorrhizal fungi, compared with plants grown in low P soil. The number of eggs per female nematode on mycorrhizal and nonmycorrhizal plants was not influenced by P treatment. Tomato plants with split root systems grown in double-compartment containers which had either low P soil in both sides or high P in one side and low P in the other, were inoculated at transplanting with G. margarita and 2 wk later one-half of the split root system of each plant was inoculated with M. incognita larvae. Although the mycoorhizal fungus increased the inorganic P content of the root to a level comparable to that in plants grown in high P soil, nematode penetration and reproduction were not altered. In a third series of experiments, the rate of nematode development was not influenced by either the presence of G. margarita or high soil P, compared with control plants grown in low P soil. These data indicate that supplemental P (30 mu/g soil) alters root-knot nematode infection of tomato more than G. mosseae and G. margarita.

Influence of arbuscular mycorrhizae on photosynthesis and water status of maize plants under salt stress.

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Sheng, Min; Tang, Ming; Chen, Hui; Yang, Baowei; Zhang, Fengfeng; Huang, Yanhui

2008-09-01

The influence of arbuscular mycorrhizal (AM) fungus Glomus mosseae on characteristics of the growth, water status, chlorophyll concentration, gas exchange, and chlorophyll fluorescence of maize plants under salt stress was studied in the greenhouse. Maize plants were grown in sand and soil mixture with five NaCl levels (0, 0.5, 1.0, 1.5, and 2.0 g/kg dry substrate) for 55 days, following 15 days of non-saline pretreatment. Under salt stress, mycorrhizal maize plants had higher dry weight of shoot and root, higher relative chlorophyll content, better water status (decreased water saturation deficit, increased water use efficiency, and relative water content), higher gas exchange capacity (increased photosynthetic rate, stomatal conductance and transpiration rate, and decreased intercellular CO(2) concentration), higher non-photochemistry efficiency [increased non-photochemical quenching values (NPQ)], and higher photochemistry efficiency [increased the maximum quantum yield in the dark-adapted state (Fv/Fm), the maximum quantum yield in the light-adapted sate (Fv'/Fm'), the actual quantum yield in the light-adapted steady state (phiPSII) and the photochemical quenching values (qP)], compared with non-mycorrhizal maize plants. In addition, AM symbiosis could trigger the regulation of the energy biturcation between photochemical and non-photochemical events reflected in the deexcitation rate constants (kN, kN', kP, and kP'). All the results show that G. mosseae alleviates the deleterious effect of salt stress on plant growth, through improving plant water status, chlorophyll concentration, and photosynthetic capacity, while the influence of AM symbiosis on photosynthetic capacity of maize plants can be indirectly affected by soil salinity and mycorrhizae-mediated enhancement of water status, but not by the mycorrhizae-mediated enhancement of chlorophyll concentration and plant biomass.

RESPUESTA DEL CULTIVO DE PIMENTÓN (CAPSICUM ANNUUM A LA INOCULACIÓN CON GLOMUS MANIHOTIS Y ACAULOSPORA LACUNOSA EN SUELO CON NIVELES ALTO DE FOSFORO

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Laura Esther Rojas-Martínez

2014-01-01

Full Text Available Background: Glomus manihotis y Acaulospora lacunosa are fungi forming arbuscular mycorrhizae; mutually beneficial symbiotic associations between fungi and specialized roots. This root-fungus formation performs various functions in association with plants. Previous research has shown that they can provide biological substitutes for mineral fertilizers. Objective: The objective of the study was to evaluate the effects of inoculation of Glomus manihotis (GL and Acaulospora lacunosa (ACU in pepper plants grown in soils with high levels of P. Methods: The Phillips and Hayman method was used for the determination of the percentage of infection. Other variables were: height, total fresh weight, shoot dry weight, root length, weight and number of fruit, percentage of infection and foliage nutrient content. Results: Plants inoculated with (GL recorded an infection rate of 70.3 %, inoculated with (ACU had 45 % and the inoculated treatment (GL / ACU 28%. The infection had a positive effect in the majority agronomic variables analyzed in plants inoculated with (GL and (ACU, but not in the mixed treatment (GL / ACU which was very similar to control. In terms of the content of nutrients in foliage, there were no significant differences in treatments NPK, but there were significant differences in the mobile few nutrients such as Zn, Cu and Fe, favoring plants inoculated with (ACU. Conclusions: These results suggest that inoculation with mycorrhizal fungi in conditions of high phosphorus levels may be an effective adjuvant in the optimal development of a plant, long as they determine the effective specific fungus under these conditions.

Synergistic and individual effect of glomus etunicatum root colonization and acetyl salicylic acid on root activity and architecture of tomato plants under moderate nacl stress

International Nuclear Information System (INIS)

Ghanzanfar, B.; Cheng, Z.; Ahmad, I.; Khan, A. R.; Hanqiang, L.; Haiyan, D.; Fang, C.

2015-01-01

A pot based experiment in plastic tunnel was conducted to investigate the changes in root morphology and root activity of the tomato plants grown under moderate NaCl stress (100 mM), pretreated with arbuscular mycorrhizal fungus AMF (Glomus etunicatum) root colonization and acetyl salicylic acid (ASA) as salinity ameliorative agents. The results revealed that both AMF and ASA treatments significantly enhanced the fresh root weight and root morphological parameters; net length, surface area, volume, mean diameter, nodal count and number of tips to different extents as compared to those of sole salinity treatment at 90 days after transplantation. Both treatments; AMF alone and in combination with ASA significantly enhanced the root activity level in terms of triphenyl tetrazolium chloride (TTC) reduction (2.37 and 2.40 mg g /sup -1/ h /sup -1/ respectively) as compared to the sole salinity treatment (0.40 mg g /sup -1/ h /sup -1/ ) as well as the salt free control (1.69 mg g /sup -1/ h /sup -1/) On the other hand, ASA treatment alone also uplifted root activity (1.53 mg g /sup -1/ h /sup -1/ ) which was significantly higher than that of sole salt treatment. It was inferred that under moderate saline conditions (100 mM NaCl), AMF (Glomus etunicatum) and ASA (individually or in combination) confer protective effect on plant growth by enhanced root activity and improved root architecture. Therefore, synergistic use of AMF (G. etunicatum) and ASA can be eco-friendly and economically feasible option for tomato production in marginally salt affected lands and suggests further investigations. (author)

Ammonia Assimilation in Zea mays L. Infected with a Vesicular-Arbuscular Mycorrhizal Fungus Glomus fasciculatum.

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Cliquet, J. B.; Stewart, G. R.

1993-03-01

To investigate nitrogen assimilation and translocation in Zea mays L. colonized by the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum (Thax. sensu Gerd.), we measured key enzyme activities, 15N incorporation into free amino acids, and 15N translocation from roots to shoots. Glutamine synthetase and nitrate reductase activities were increased in both roots and shoots compared with control plants, and glutamate dehydrogenase activity increased in roots only. In the presence of [15N]ammonium, glutamine amide was the most heavily labeled product. More label was incorporated into amino acids in VAM plants. The kinetics of 15N labeling and effects of methionine sulfoximine on distribution of 15N-labeled products were entirely consistent with the operation of the glutamate synthase cycle. No evidence was found for ammonium assimilation via glutamate dehydrogenase. 15N translocation from roots to shoots through the xylem was higher in VAM plants compared with control plants. These results establish that, in maize, VAM fungi increase ammonium assimilation, glutamine production, and xylem nitrogen translocation. Unlike some ectomycorrhizal fungi, VAM fungi do not appear to alter the pathway of ammonium assimilation in roots of their hosts.

Influence of Species of Vesicular-Arbuscular Mycorrhizal Fungi and Phosphorus Nutrition on Growth, Development, and Mineral Nutrition of Potato (Solanum tuberosum L.).

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McArthur, DAJ.; Knowles, N. R.

1993-07-01

Growth, development, and mineral physiology of potato (Solanum tuberosum L.) plants in response to infection by three species of vesicular-arbuscular mycorrhizal (VAM) fungi and different levels of P nutrition were characterized. P deficiency in no-P and low-P (0.5 mM) nonmycorrhizal plants developed between 28 and 84 d after planting. By 84 d after planting, P deficiency decreased plant relative growth rate such that no-P and low-P plants had, respectively, 65 and 45% less dry mass and 76 and 55% less total P than plants grown with high P (2.5 mM). A severe reduction in leaf area was also evident, because P deficiency induced a restriction of lateral bud growth and leaf expansion and, also, decreased the relative plant allocation of dry matter to leaf growth. Root growth was less influenced by P deficiency than either leaf or stem growth. Moreover, P-deficient plants accumulated a higher proportion of total available P than high-P plants, indicating that P stress had enhanced root efficiency of P acquisition. Plant P deficiency did not alter the shoot concentration of N, K, Mg, or Fe; however, the total accumulation of these mineral nutrients in shoots of P-stressed plants was substantially less than that of high-P plants. P uptake by roots was enhanced by each of the VAM symbionts by 56 d after planting and at all levels of abiotic P supply. Species differed in their ability to colonize roots and similarly to produce a plant growth response. In this regard, Glomus intraradices (Schenck and Smith) enhanced plant growth the most, whereas Glomus dimorphicum (Boyetchko and Tewari) was least effective, and Glomus mosseae ([Nicol. and Gerd.] Gerd. and Trappe) produced an intermediate growth response. The partial alleviation of P deficiency in no-P and low-P plants by VAM fungi stimulated uptake of N, K, Mg, Fe, and Zn. VAM fungi enhanced shoot concentrations of P, N, and Mg by 28 d after planting and, through a general improvement of overall plant mineral nutrition

Sustainable management of root-knot disease of tomato by neem cake and Glomus fasciculatum

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Rose Rizvi

2015-12-01

Full Text Available A pot experiment was conducted during winter season of 2009–2010 in the department of Botany, AMU, Aligarh, India, to determine the nematicidal potential of organic matter, neem cake at third level of dose, and bioagent, Glomus fasciculatum in terms of various growth parameters of tomato, when inoculated individually as well as concomitantly with respect to root-knot development. Neem cake and G. fasciculatum showed potential for sustainable management while providing nutrient sources for proper plant growth. Disease intensity of root-knot nematode decreased while increasing the doses of neem cake along with the G. fasciculatum. Chlorophyll contents have been found to be increased in single and combined application as well. There is a progressive increase in growth parameters raised in soil amended with 10, 20, and 30 g neem cake/kg soil and inoculated with G. fasciculatum. Significant improvement in the plant growth was observed when G. fasciculatum and neem cake were inoculated simultaneously. Neem cake plus G. fasciculatum reduced the nematodes’ multiplication and root-galling, and increased the plant growth of tomato as compared to unamended and Meloidogyne incognita-inoculated plants. Mycorrhyzation and agronomic parameters were increased due to application of G. fasciculatum alone, but enhanced further when inoculated with neem cake.

Endoproteolytic activities in pea roots inoculated with the arbuscular mycorrhizal fungus Glomus mosseae and/orAphanomyces euteiches in relation to bioprotection

DEFF Research Database (Denmark)

Slezack, S; DUMAS-GAUDOT, E; Rosendahl, Søren

1999-01-01

as 'trypsin-like' serine endoproteases. Interestingly, in a situation of bioprotection, only low levels of the activities normally associated with the infection by A. euteiches were detected, suggesting that the synthesis of these proteins is directly linked to the growth or virulence of the pathogen....

Enhancement of the efficacy of a carbamate nematicide against the potato cyst nematode, Globodera pallida, through mycorrhization in commercial potato fields.

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Deliopoulos, T; Minnis, S T; Jones, P W; Haydock, P P J

2010-03-01

Two experiments were conducted over 2 years in commercial potato fields in Shropshire, UK, to evaluate the compatibility of the nematicide aldicarb with commercial inocula of arbuscular mycorrhizal fungi (AMF) in the control of the potato cyst nematode Globodera pallida. The AMF used were Vaminoc (mixed-AMF inoculum), Glomus intraradices (BioRize BB-E) and G. mosseae (isolate BEG 12). In the absence of AMF, the in-soil hatch of G. pallida increased 30% (P potato (cv. Golden Wonder) tubers with AMF eliminated this delay in G. pallida hatch by stimulating a mean increase of 32% (P < 0.01) in hatch within 2 wk after planting. In the aldicarb-treated plots in Experiment 1, G. pallida multiplication rate was 38% lower (P < 0.05) in roots of AMF-inoculated than noninoculated plants, but in Experiment 2, this effect was slightly lower (P = 0.07). In these plots, the single AMF inocula showed also a weak trend (P = 0.10) towards greater tuber yields relative to their noninoculated counterparts. Mycorrhization therefore appears to enhance the efficacy of carbamate nematicides against G. pallida and consequently more research is proposed to validate these findings and fully explore the potential of this model.

Role of extrinsic arbuscular mycorrhizal fungi in heavy metal-contaminated wetlands with various soil moisture levels.

Science.gov (United States)

Zheng, S; Wang, C; Shen, Z; Quan, Y; Liu, X

2015-01-01

This study presents an efficient heavy metal (HM) control method in HM-contaminated wetlands with varied soil moisture levels through the introduction of extrinsic arbuscular mycorrhizal fungi (AMF) into natural wetland soil containing indigenous AMF species. A pot culture experiment was designed to determine the effect of two soil water contents (5-8% and 25-30%), five extrinsic AMF inoculants (Glomus mosseae, G. clarum, G. claroideum, G. etunicatum, and G. intraradices), and HM contamination on root colonization, plant growth, and element uptake of common reed (Phragmites australis (Cav.) Trin. ex Steudel) plantlets in wetland soils. This study showed the prevalence of mycorrhizae in the roots of all P. australis plantlets, regardless of extrinsic AMF inoculations, varied soil moisture or HM levels. It seems that different extrinsic AMF inoculations effectively lowered HM concentrations in the aboveground tissues of P. australis at two soil moisture levels. However, metal species, metal concentrations, and soil moisture should also be very important factors influencing the elemental uptake performance of plants in wetland ecosystems. Besides, the soil moisture level significantly influenced plant growth (including height, and shoot and root dry weight (DW)), and extrinsic AMF inoculations differently affected shoot DW.

Specific interactions between arbuscular mycorrhizal fungi and plant growth-promoting bacteria--as revealed by different combinations

Energy Technology Data Exchange (ETDEWEB)

Jaderlund, Lotta; Arthurson, Veronica; Granhall, Ulf; Jansson, Janet K.

2008-05-15

The interactions between two plant growth promoting rhizobacteria (PGPR), Pseudomonas fluorescens SBW25 and Paenibacillus brasilensis PB177, two arbuscular mycorrhizal (AM) fungi (Glomus mosseae and G. intraradices) and one pathogenic fungus (Microdochium nivale) were investigated on winter wheat (Triticum aestivum cultivar Tarso) in a greenhouse trial. PB177, but not SBW25, had strong inhibitory effects on M. nivale in dual culture plate assays. The results from the greenhouse experiment show very specific interactions; e.g. the two AM fungi react differently when interacting with the same bacteria on plants. G. intraradices (single inoculation or together with SBW25) increased plant dry weight on M. nivale infested plants, suggesting that the pathogenic fungus is counteracted by G. intraradices, but PB177 inhibited this positive effect. This is an example of two completely different reactions between the same AM fungus and two species of bacteria, previously known to enhance plant growth and inhibit pathogens. When searching for plant growth promoting microorganisms it is therefore important to test for the most suitable combination of plant, bacteria and fungi in order to get satisfactory plant growth benefits.

Weed control and cover crop management affect mycorrhizal colonization of grapevine roots and arbuscular mycorrhizal fungal spore populations in a California vineyard.

Science.gov (United States)

Baumgartner, Kendra; Smith, Richard F; Bettiga, Larry

2005-03-01

Arbuscular mycorrhizal (AM) fungi naturally colonize grapevines in California vineyards. Weed control and cover cropping may affect AM fungi directly, through destruction of extraradical hyphae by soil disruption, or indirectly, through effects on populations of mycorrhizal weeds and cover crops. We examined the effects of weed control (cultivation, post-emergence herbicides, pre-emergence herbicides) and cover crops (Secale cereale cv. Merced rye, x Triticosecale cv.Trios 102) on AM fungi in a Central Coast vineyard. Seasonal changes in grapevine mycorrhizal colonization differed among weed control treatments, but did not correspond with seasonal changes in total weed frequency. Differences in grapevine colonization among weed control treatments may be due to differences in mycorrhizal status and/or AM fungal species composition among dominant weed species. Cover crops had no effect on grapevine mycorrhizal colonization, despite higher spring spore populations in cover cropped middles compared to bare middles. Cover crops were mycorrhizal and shared four AM fungal species (Glomus aggregatum, G. etunicatum, G. mosseae, G. scintillans) in common with grapevines. Lack of contact between grapevine roots and cover crop roots may have prevented grapevines from accessing higher spore populations in the middles.

Variability in growth, nutrition and phytochemical constituents of Plectranthus amboinicus (Lour Spreng. as influenced by indigenous arbuscular mycorrhizal fungi

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Sevanan Rajeshkumar

2008-07-01

Full Text Available A study was conducted under greenhouse nursery condition on the efficacy of seven indigenous arbuscular mycorrhizal (AM fungi in the improvement of growth, biomass, nutrition and phytochemical constituents, namely total phenols, ortho dihydroxy phenols, flavonoids, alkaloids, tannins and saponins, in the roots and leaves of Plectranthus amboinicus (Lour Spreng. Seedlings were raised in polythene bags containing soil inoculated with isolates of seven different indigenous AM fungi, viz. Acaulospora bireticulata, A. scrobiculata, Gigaspora margarita, Glomus aggregatum, G. mosseae, G. geosporum, and Scutellospora heterogama. P. amboinicus seedlings raised in the presence of AM fungi generally showed an increase in plant growth, nutritional status and phytochemical constituents over those grown in the absence of AM fungi. The extent of growth, biomass, nutritional status and phytochemical constituents enhanced by AM fungi varied with the species of AM fungi inhabiting the roots and leaves of P. amboinicus seedlings. Considering the various plant growth parameters, nutritional status of the plant, total phenols, ortho dihydroxy phenols, alkaloids , flavonoids , tannins, and saponins in the roots and leaves, it was observed that Gigaspora margarita is the best AM symbiont for P. amboinicus used in this experiment.

Produção de mudas de goiabeira (Psidium guajava L., inoculadas com o fungo micorrízico arbuscular Glomus clarum, em substrato agro-industrial Production of guava ( Psidium guajava L. plants inoculated with arbuscular mycorrhizal fungi Glomus clarum, in agro-industrial substrate

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JOLIMAR ANTONIO SCHIAVO

2002-08-01

Full Text Available Conduziu-se um experimento em casa de vegetação, com o objetivo de avaliar o crescimento de mudas de goiabeira (Psidium guajava L., produzidas em blocos prensados, confeccionados com resíduos agro-industriais, e inoculadas com o fungo micorrízico arbuscular (FMA Glomus clarum Nicolson & Schenck. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 2 x 2, sendo 2 tratamentos microbiológicos: controle e FMA; e 2 sistemas de produção de mudas: blocos prensados (nova metodologia e tubetes plásticos (tradicional, com 5 repetições. O substrato utilizado para a confecção dos blocos prensados e enchimento dos tubetes foi constituído por uma mistura de bagaço de cana-de-açúcar e torta de filtro (3:1 v/v. O FMA proporcionou aumentos significativos na produção de matéria seca, conteúdo de N e P da parte aérea da goiabeira, apenas no sistema de produção das mudas em blocos prensados. Mudas produzidas e inoculadas em blocos prensados mostraram um aumento de 88% na matéria seca da parte aérea, 82% e 89% para os conteúdos de nitrogênio e fósforo da parte aérea, respectivamente, em relação ao tratamento-controle.A greenhouse experiment was carried out to evaluate the growth of guava plant seedlings, inoculated with arbuscular mycorrhizal fungi (AMF, Glomus clarum Nicolson & Schenck, produced in pressed blocks made with agro-industrial residues. The experimental design utilized was a completely randomized in factorial 2x2, having two microbiological treatments: control and inoculated; two systems of production: pressed blocks (new methodology and plastic tubes (traditional, with 5 repetitions. The substrate utilized to make the pressed blocks and to fill the plastic tubes was constituted by a mixture of sugarcane bagasse and filter cake (3:1 v/v. The AMF inoculation led to a significant increase in dry matter yield and nutrients content of shoot plants, only in pressed blocks. Plants produced in

Microsurgical Resection of Glomus Jugulare Tumors With Facial Nerve Reconstruction: 3-Dimensional Operative Video.

Science.gov (United States)

Cândido, Duarte N C; de Oliveira, Jean Gonçalves; Borba, Luis A B

2018-05-08

Paragangliomas are tumors originating from the paraganglionic system (autonomic nervous system), mostly found at the region around the jugular bulb, for which reason they are also termed glomus jugulare tumors (GJT). Although these lesions appear to be histologically benign, clinically they present with great morbidity, especially due to invasion of nearby structures such as the lower cranial nerves. These are challenging tumors, as they need complex approaches and great knowledge of the skull base. We present the case of a 31-year-old woman, operated by the senior author, with a 1-year history of tinnitus, vertigo, and progressive hearing loss, that evolved with facial nerve palsy (House-Brackmann IV) 2 months before surgery. Magnetic resonance imaging and computed tomography scans demonstrated a typical lesion with intense flow voids at the jugular foramen region with invasion of the petrous and tympanic bone, carotid canal, and middle ear, and extending to the infratemporal fossa (type C2 of Fisch's classification for GJT). During the procedure the mastoid part of the facial nerve was identified involved by tumor and needed to be resected. We also describe the technique for nerve reconstruction, using an interposition graft from the great auricular nerve, harvested at the beginning of the surgery. We achieved total tumor resection with a remarkable postoperative course. The patient also presented with facial function after 6 months. The patient consented with publication of her images.

Fractionated stereotactic radiotherapy of glomus jugulare tumors. Local control, toxicity, symptomatology, and quality of life

International Nuclear Information System (INIS)

Henzel, M.; Gross, M.W.; Failing, T.; Strassmann, G.; Engenhart-Cabillic, R.; Hamm, K.; Surber, G.; Kleinert, G.; Sitter, H.

2007-01-01

Background and Purpose: For glomus jugulare tumors, the goal of treatment is microsurgical excision. To minimize postoperative neurologic deficits, stereotactic radiosurgery (SRS) was performed as an alternative treatment option. Stereotactic fractionated radiotherapy (SRT) could be a further alternative. This study aims at the assessment of local control, side effects, and quality of life (QoL). Patients and Methods: Between 1999-2005, 17 patients were treated with SRT. 11/17 underwent previous operations. 6/17 received primary SRT. Treatment was delivered by a linear accelerator with 6-MV photons. Median cumulative dose was 57.0 Gy. Local control, radiologic regression, toxicity, and symptomatology were evaluated half-yearly by clinical examination and MRI scans. QoL was assessed by Short Form-36 (SF-36). Results: Median follow-up was 40 months. Freedom from progression and overall survival for 5 years were 100% and 93.8%. Radiologic regression was seen in 5/16 cases, 11/16 patients were stable. Median tumor shrinkage was 17.9% (p = 0.14). Severe acute toxicity (grade 3-4) or any late toxicity was never seen. Main symptoms improved in 9/16 patients, 7/16 were stable. QoL was not affected in patients receiving primary SRT. Conclusion: SRT offers an additional treatment option of high efficacy with less side effects, especially in cases of large tumors, morbidity, or recurrences after incomplete resections. (orig.)

Arbuscular mycorrhizal symbiosis mitigates the negative effects of salinity on durum wheat

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Ingraffia, Rosolino; Giambalvo, Dario; Frenda, Alfonso Salvatore

2017-01-01

Arbuscular mycorrhizal (AM) symbiosis is generally considered to be effective in ameliorating the plant tolerance to salt stress. Unfortunately, the comprehension of the mechanisms implicated in salinity stress alleviation by AM symbiosis is far from being complete. Thus, an experiment was performed by growing durum wheat (Triticum durum Desf.) plants under salt-stress conditions to evaluate the influence of AM symbiosis on both the plant growth and the regulation of a number of genes related to salt stress and nutrient uptake. Durum wheat plants were grown outdoors in pots in absence or in presence of salt stress and with or without AM fungi inoculation. The inoculum consisted of a mixture of spores of Rhizophagus irregularis (formerly Glomus intraradices) and Funneliformis mosseae (formerly G. mosseae). Results indicate that AM symbiosis can alleviate the detrimental effects of salt stress on the growth of durum wheat plants. In fact, under salt stress conditions mycorrhizal plants produced more aboveground and root biomass, had higher N uptake and aboveground N concentration, and showed greater stability of plasma membranes compared to non-mycorrhizal plants. Inoculation with AM fungi had no effect on the expression of the N transporter genes AMT1.1, AMT1.2, and NAR2.2, either under no-stress or salt stress conditions, probably due to the fact that plants were grown under optimal N conditions; on the contrary, NRT1.1 was always upregulated by AM symbiosis. Moreover, the level of expression of the drought stress-related genes AQP1, AQP4, PIP1, DREB5, and DHN15.3 observed in the mycorrhizal stressed plants was markedly lower than that observed in the non-mycorrhizal stressed plants and very close to that observed in the non-stressed plants. Our hypothesis is that, in the present study, AM symbiosis did not increase the plant tolerance to salt stress but instead generated a condition in which plants were subjected to a level of salt stress lower than that of non

Arbuscular mycorrhizal symbiosis mitigates the negative effects of salinity on durum wheat.

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Fileccia, Veronica; Ruisi, Paolo; Ingraffia, Rosolino; Giambalvo, Dario; Frenda, Alfonso Salvatore; Martinelli, Federico

2017-01-01

Arbuscular mycorrhizal (AM) symbiosis is generally considered to be effective in ameliorating the plant tolerance to salt stress. Unfortunately, the comprehension of the mechanisms implicated in salinity stress alleviation by AM symbiosis is far from being complete. Thus, an experiment was performed by growing durum wheat (Triticum durum Desf.) plants under salt-stress conditions to evaluate the influence of AM symbiosis on both the plant growth and the regulation of a number of genes related to salt stress and nutrient uptake. Durum wheat plants were grown outdoors in pots in absence or in presence of salt stress and with or without AM fungi inoculation. The inoculum consisted of a mixture of spores of Rhizophagus irregularis (formerly Glomus intraradices) and Funneliformis mosseae (formerly G. mosseae). Results indicate that AM symbiosis can alleviate the detrimental effects of salt stress on the growth of durum wheat plants. In fact, under salt stress conditions mycorrhizal plants produced more aboveground and root biomass, had higher N uptake and aboveground N concentration, and showed greater stability of plasma membranes compared to non-mycorrhizal plants. Inoculation with AM fungi had no effect on the expression of the N transporter genes AMT1.1, AMT1.2, and NAR2.2, either under no-stress or salt stress conditions, probably due to the fact that plants were grown under optimal N conditions; on the contrary, NRT1.1 was always upregulated by AM symbiosis. Moreover, the level of expression of the drought stress-related genes AQP1, AQP4, PIP1, DREB5, and DHN15.3 observed in the mycorrhizal stressed plants was markedly lower than that observed in the non-mycorrhizal stressed plants and very close to that observed in the non-stressed plants. Our hypothesis is that, in the present study, AM symbiosis did not increase the plant tolerance to salt stress but instead generated a condition in which plants were subjected to a level of salt stress lower than that of non

Rhizobial Nodulation Factors Stimulate Mycorrhizal Colonization of Nodulating and Nonnodulating Soybeans.

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Xie, Z. P.; Staehelin, C.; Vierheilig, H.; Wiemken, A.; Jabbouri, S.; Broughton, W. J.; Vogeli-Lange, R.; Boller, T.

1995-08-01

Legumes form tripartite symbiotic associations with noduleinducing rhizobia and vesicular-arbuscular mycorrhizal fungi. Co-inoculation of soybean (Glycine max [L.] Merr.) roots with Bradyrhizobium japonicum 61-A-101 considerably enhanced colonization by the mycorrhizal fungus Glomus mosseae. A similar stimulatory effect on mycorrhizal colonization was also observed in nonnodulating soybean mutants when inoculated with Bradyrhizobium japonicum and in wild-type soybean plants when inoculated with ineffective rhizobial strains, indicating that a functional rhizobial symbiosis is not necessary for enhanced mycorrhiza formation. Inoculation with the mutant Rhizobium sp. NGR[delta]nodABC, unable to produce nodulation (Nod) factors, did not show any effect on mycorrhiza. Highly purified Nod factors also increased the degree of mycorrhizal colonization. Nod factors from Rhizobium sp. NGR234 differed in their potential to promote fungal colonization. The acetylated factor NodNGR-V (MeFuc, Ac), added at concentrations as low as 10-9 M, was active, whereas the sulfated factor, NodNGR-V (MeFuc, S), was inactive. Several soybean flavonoids known to accumulate in response to the acetylated Nod factor showed a similar promoting effect on mycorrhiza. These results suggest that plant flavonoids mediate the Nod factor-induced stimulation of mycorrhizal colonization in soybean roots.

Can arbuscular mycorrhiza and fertilizer management reduce phosphorus runoff from paddy fields?

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Zhang, Shujuan; Wang, Li; Ma, Fang; Zhang, Xue; Li, Zhe; Li, Shiyang; Jiang, Xiaofeng

2015-07-01

Our study sought to assess how much phosphorus (P) runoff from paddy fields could be cut down by fertilizer management and inoculation with arbuscular mycorrhizal fungi. A field experiment was conducted in Lalin River basin, in the northeast China: six nitrogen-phosphorus-potassium fertilizer levels were provided (0, 20%, 40%, 60%, 80%, and 100% of the recommended fertilizer supply), with or without inoculation with Glomus mosseae. The volume and concentrations of particle P (PP) and dissolved P (DP) were measured for each runoff during the rice growing season. It was found that the seasonal P runoff, including DP and PP, under the local fertilization was 3.7 kg/ha, with PP, rather than DP, being the main form of P in runoff water. Additionally, the seasonal P runoff dropped only by 8.9% when fertilization decreased by 20%; rice yields decreased with declining fertilization. We also found that inoculation increased rice yields and decreased P runoff at each fertilizer level and these effects were lower under higher fertilization. Conclusively, while rice yields were guaranteed arbuscular mycorrhizal inoculation and fertilizer management would play a key role in reducing P runoff from paddy fields. Copyright © 2015. Published by Elsevier B.V.

EFFECT OF MYCORRHIZAL INOCULANTS IN THE DEVELOPMENT OF MEXICAN LANDRACE AVOCADO ROOTSTOCKS

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Edgar Castro Alvarado

2013-12-01

Full Text Available The aim of this work was to assess the effect of two arbuscular mycorrhizal fungi (AMF inoculants in the development of avocado rootstocks. Seeds of Mexican landrace avocado (Persea americana Mill. var. drymifolia were used, with two commercial inoculants: T1 containing Glomus fasciculatum, G. constrictum, G. tortuosum, G. geosporum,and Acaulospora scrobiculata, and T2, containing G. mosseae and G. cubense.  The plants inoculated with AMF showed more rapid growth than the no inoculant control as measured by plant height (50% and 54%, stem diameter (35% and 36%, leaf number (48% and 37% and length (31% and 40%, and root fresh weight (85% and 59%; however, no significant differences were observed between T1 and T2. The chlorophyll concentration in the leaves from T1 was 16.4% and T2 was 19% higher than the control suggesting a higher photosynthetic capacity in T1 and T2. Finally the shoot/root ratio, as indicator of the potential development of plantations, was 79% and 50% higher in mycorrhizal plants than in the control. In conclusion both T1 and T2 inoculants improved growth rate and vigor of avocado nursery rootstocks producing higher quality plants.

Arbuscular mycorrhizal (Funneliformis mosseae improves alfalfa (Medicago sativa L. re-growth ability in saline soil through enhanced nitrogen remobilization and improved nutritional balance

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Amin Namdari

2018-03-01

Full Text Available In current study, the influence of arbuscular mycorrhizal fungi (AMF on salinity tolerance in terms of root’s reserves remobilization to shoot and its relationship with re-growth ability and ionic status of alfalfa (Medicago sativa L. plants were investigated. In a pot experiment, a factorial experiment in base of randomized complete blocks design in three replications was carried out. Alfalfa plants (Iranian cultivar-Baghdadi inoculated with AMF (Funneliformis mosseae or retained as un-inoculated, were grown in soil and irrigated with three salt concentrations including 1.4 (control, 7 and 12 dS/m. Three harvests were carried out at 10% of flowering stage. AMF inoculation increased the size of root sugars and soluble N pools at harvest time. The shoot biomass production following harvest had a close correlation with nitrogen (N remobilization from root (r=0.92, P≤0.01. However salinity stress significantly reduced amount and percentage of N remobilization to re-growing shoot but AMF plants exhibited greater amount and percentage of root N pools dedicated to remobilization. AMF inoculation also affected ionic relations of plants as AM+ plants contained greater K+ within both root and shoot organs while Ca2+ and Na+ were affected by AMF only within shoot tissue. AMF plants exhibited higher K+/Na+ within shoot and Ca+2/Na+ within root organs. There was a high positive correlation coefficient between K+/Na+, Ca+2/Na+ ratios and N remobilization from root (respectively, r=0.92, 0.88; P≤0.01. To sum up, ionic status within both root and shoot organs, got more balanced by AMF inoculation so that AMF reduced limitations within both source (root and sink (re-growing shoot organs concerning N remobilization to re-growing shoot.

Differential effects of cadmium and chromium on growth, photosynthetic activity, and metal uptake of Linum usitatissimum in association with Glomus intraradices.

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Amna; Ali, Naeem; Masood, Sajid; Mukhtar, Tehmeena; Kamran, Muhammad Aqeel; Rafique, Mazhar; Munis, M Farooq Hussain; Chaudhary, Hassan Javed

2015-06-01

The current study was aimed at analyzing the differential effects of heavy metals (cadmium and chromium) and mycorrhizal fungus; Glomus intraradices on growth, chlorophyll content, proline production, and metal accumulation in flax plant (Linum usitatissimum L.). Heavy metal accumulation rate in flax varied from 90 to 95 % for Cd and 61-84 % for Cr at a concentration range of 250 to 500 ppm for both metals in 24 days of experiment. Growth and photosynthetic activity of flax reduced to an average of 21 and 45 %, respectively. However, inoculation of G. intraradices significantly increased the plant biomass even under metal stressed conditions. Additionally, mycorrhizal association also assists the Cd and Cr increased uptake by 23 and 33 %, respectively. Due to metal stress, chlorophyll contents were decreased by 27 and 45 %, while 84 and 71 % increased proline content was observed under Cd and Cr stress, respectively. The present results clearly signify the differential response and potential of flax plant towards heavy metal tolerance and accumulation that can further increase with mycorrhizal fungus.

Desvascularización preoperatoria de tumor del glomus mediante colocación de stent cubierto en la carótida externa

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Sergio A. Garrido

2010-01-01

Full Text Available RESUMENLos tumores del glomus carotídeo se caracterizan por su vascularización importante y sumanejo preoperatorio puede incluir la embolización percutánea previa a la resección quirúrgica.Esta técnica disminuye la hemorragia y el tamaño del tumor y hace menos riesgosala disección, con reducción de la morbimortalidad. Una técnica alternativa es la interrupciónde la irrigación del tumor mediante la colocación de un stent cubierto en la carótidaexterna, que es la vía principal de irrigación. Esta técnica es útil en especial en tumoresgrandes y evita el riesgo de embolia intracraneal cuando se emplean coils para realizar laembolización. En esta presentación se describe el caso de una paciente de 31 años tratadade esta manera; se le colocó el stent y 24 horas después se realizó la resección del tumor.REV ARGENT CARDIOL 2010;78:252-254.

Gamma Knife radiosurgery for glomus jugulare tumors: a single-center series of 75 cases.

Science.gov (United States)

Ibrahim, Ramez; Ammori, Mohannad B; Yianni, John; Grainger, Alison; Rowe, Jeremy; Radatz, Matthias

2017-05-01

OBJECTIVE Glomus jugulare tumors are rare indolent tumors that frequently involve the lower cranial nerves (CNs). Complete resection can be difficult and associated with lower CN injury. Gamma Knife radiosurgery (GKRS) has established its role as a noninvasive alternative treatment option for these often formidable lesions. The authors aimed to review their experience at the National Centre for Stereotactic Radiosurgery, Sheffield, United Kingdom, specifically the long-term tumor control rate and complications of GKRS for these lesions. METHODS Clinical and radiological data were retrospectively reviewed for patients treated between March 1994 and December 2010. Data were available for 75 patients harboring 76 tumors. The tumors in 3 patients were treated in 2 stages. Familial and/or hereditary history was noted in 12 patients, 2 of whom had catecholamine-secreting and/or active tumors. Gamma Knife radiosurgery was the primary treatment modality in 47 patients (63%). The median age at the time of treatment was 55 years. The median tumor volume was 7 cm 3 , and the median radiosurgical dose to the tumor margin was 18 Gy (range 12-25 Gy). The median duration of radiological follow-up was 51.5 months (range 12-230 months), and the median clinical follow-up was 38.5 months (range 6-223 months). RESULTS The overall tumor control rate was 93.4% with low CN morbidity. Improvement of preexisting deficits was noted in 15 patients (20%). A stationary clinical course and no progression of symptoms were noted in 48 patients (64%). Twelve patients (16%) had new symptoms or progression of their preexisting symptoms. The Kaplan-Meier actuarial tumor control rate was 92.2% at 5 years and 86.3% at 10 years. CONCLUSIONS Gamma Knife radiosurgery offers a risk-versus-benefit treatment option with very low CN morbidity and stable long-term results.

Survey the Effect of Mycorrhiza and Azospirillum of Wheat Cultivars Resistance in Yellow Rust

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M. Jiriaie

2017-01-01

Full Text Available Introduction: Wheat is one of the major agricultural crops with respect to human nutrition. It is cultivated over a wide range of environments, because of wide adaptation to diverse environmental conditions. In Iran, 6.2 million hectares are under wheat cultivation, of which 33% is irrigated and 67% is rain-fed, the irrigated wheat growing areas (2 million hectares are located mostly in southern, central and east of Iran Production of crops is under the influence of plant genetic structure, environmental conditions and their interactions. Biotic and abiotic stresses are considered to lower production. Among the biotic stress, the fungal disease is the main factor limiting production of crop plants in hot and humid regions. Stripe rust was not a serious economic concern to the wheat industry for most of the 1990’s due to the use of resistant varieties. However, by 2003 it had developed into a significant issue, particularly as new path types evolved. Even in the dry years of 2003 and 2004, stripe rust cost growers significant income. Provide country's need for wheat as a strategic product, meanwhile, production is free from chemical fungicide is a high but achievable goal. So in order to achieve fertilizer and fungicide resources that in addition to having no adverse effects on consumers and the environment, has been economically able to provide nutrition need of crop plant, is very important. Materials and Methods: With this approach, to survey the effect of Mycorrhiza and Azospirillum in resistance to yellow rust in wheat cultivars, an experiment was conducted at the research station of the Shahid Chamran University of Ahvaz, Iran in 2012-13. The experimental design was factorial based on a randomized complete block design with three replications. The treatments include of Mycorrhiza fungi in three levels (without application of Mycorrhiza strain and using strain Glomus intraradices and Glomus mosseae, Azospirillum lipoferum bacterium in two

Gamma knife radiosurgery for glomus jugulare tumors: therapeutic advantages of minimalism in the skull base.

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Sharma, Manish S; Gupta, A; Kale, S S; Agrawal, D; Mahapatra, A K; Sharma, B S

2008-01-01

Glomus jugulare (GJ) tumors are paragangliomas found in the region of the jugular foramen. Surgery with/without embolization and conventional radiotherapy has been the traditional management option. To analyze the efficacy of gamma knife radiosurgery (GKS) as a primary or an adjunctive form of therapy. A retrospective analysis of patients who received GKS at a tertiary neurosurgical center was performed. Of the 1601 patients who underwent GKS from 1997 to 2006, 24 patients with GJ underwent 25 procedures. The average age of the cohort was 46.6 years (range, 22-76 years) and the male to female ratio was 1:2. The most common neurological deficit was IX, X, XI cranial nerve paresis (15/24). Fifteen patients received primary GKS. Mean tumor size was 8.7 cc (range 1.1-17.2 cc). The coverage achieved was 93.1% (range 90-97%) using a mean tumor margin dose of 16.4 Gy (range 12-25 Gy) at a mean isodose of 49.5% (range 45-50%). Thirteen patients (six primary and seven secondary) were available for follow-up at a median interval of 24 months (range seven to 48 months). The average tumor size was 7.9 cc (range 1.1-17.2 cc). Using a mean tumor margin dose of 16.3 Gy (range 12-20 Gy) 93.6% coverage (range 91-97%) was achieved. Six patients improved clinically. A single patient developed transient trigeminal neuralgia. Magnetic resonance imaging follow-up was available for 10 patients; seven recorded a decrease in size. There was no tumor progression. Gamma knife radiosurgery is a safe and effective primary and secondary modality of treatment for GJ.

Effect of arbuscular mycorrhizal fungus (Glomus caledonium) on the accumulation and metabolism of atrazine in maize (Zea mays L.) and atrazine dissipation in soil

Energy Technology Data Exchange (ETDEWEB)

Huang Honglin [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 18th Shuangqinglu, Haidian District, Beijing 100085 (China); Zhang Shuzhen [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 18th Shuangqinglu, Haidian District, Beijing 100085 (China)]. E-mail: szzhang@mail.rcees.ac.cn; Shan Xiaoquan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 18th Shuangqinglu, Haidian District, Beijing 100085 (China); Chen Baodong [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 18th Shuangqinglu, Haidian District, Beijing 100085 (China); Zhu Yongguan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, 18th Shuangqinglu, Haidian District, Beijing 100085 (China); Bell, J. Nigel B. [Center for Environmental Policy, Imperial College, London (United Kingdom)

2007-03-15

Effects of an arbuscular mycorrhizal (AM) fungus (Glomus caledonium) on accumulation and metabolism of atrazine in maize grown in soil contaminated with different concentrations of atrazine were investigated in a series of pot experiments. Roots of mycorrhizal plants accumulated more atrazine than non-mycorrhizal roots. In contrast, atrazine accumulation in shoot decreased in mycorrhizal compared with non-mycorrhizal plants. No atrazine derivatives were detected in the soil, either with or without mycorrhizal colonization. However, atrazine metabolites, deethylatrazine (DEA) and deisopropylatrazine (DIA), were detected in plant roots and the AM colonization enhanced the metabolism. After plant harvest atrazine concentrations decreased markedly in the soils compared to the initial concentrations. The decreases were the most in rhizosphere soil and then near-rhizosphere soil and the least in bulk soil. Mycorrhizal treatment enhanced atrazine dissipation in the near-rhizosphere and bulk soils irrespective of atrazine application rates. - Arbuscular mycorrhizal fungus increases the accumulation and metabolism of atrazine in maize.

Effect of arbuscular mycorrhizal fungus (Glomus caledonium) on the accumulation and metabolism of atrazine in maize (Zea mays L.) and atrazine dissipation in soil

International Nuclear Information System (INIS)

Huang Honglin; Zhang Shuzhen; Shan Xiaoquan; Chen Baodong; Zhu Yongguan; Bell, J. Nigel B.

2007-01-01

Effects of an arbuscular mycorrhizal (AM) fungus (Glomus caledonium) on accumulation and metabolism of atrazine in maize grown in soil contaminated with different concentrations of atrazine were investigated in a series of pot experiments. Roots of mycorrhizal plants accumulated more atrazine than non-mycorrhizal roots. In contrast, atrazine accumulation in shoot decreased in mycorrhizal compared with non-mycorrhizal plants. No atrazine derivatives were detected in the soil, either with or without mycorrhizal colonization. However, atrazine metabolites, deethylatrazine (DEA) and deisopropylatrazine (DIA), were detected in plant roots and the AM colonization enhanced the metabolism. After plant harvest atrazine concentrations decreased markedly in the soils compared to the initial concentrations. The decreases were the most in rhizosphere soil and then near-rhizosphere soil and the least in bulk soil. Mycorrhizal treatment enhanced atrazine dissipation in the near-rhizosphere and bulk soils irrespective of atrazine application rates. - Arbuscular mycorrhizal fungus increases the accumulation and metabolism of atrazine in maize

Coupling auto trophic in vitro plant cultivation system to scanning electron microscope to study plant-fungal interactions

Energy Technology Data Exchange (ETDEWEB)

Jaeger, N. de; Decock, C.; Declereck, S.; Providencia, I. E. de la

2010-07-01

The interactions of plants with pathogens and beneficial micro-organisms have been seldom compared on the same host and under strict controlled auto trophic in vitro culture conditions. Here, the life cycle of two plant beneficial (Glomus sp. MUCL 41833 and Trichoderma harzianum) and one plant pathogen (Rhizoctonia solani) fungi were described on potato (Solanum tuberosum) plantlets under auto trophic in vitro culture conditions using video camera imaging and the scanning electron microscope (SEM). (i) The colony developmental pattern of the extraradical mycelium within the substrate, (ii) the reproduction structures and (iii) the three-dimensional spatial arrangements of the fungal hyphae within the potato root cells were successfully visualized, monitored and described. The combination of the autotrophic in vitro culture system and SEM represent a powerful tool for improving our knowledge on the dynamics of plant-fungal interactions. (Author) 41 refs.

Microsurgical anatomy of the human carotid body (glomus caroticum): Features of its detailed topography, syntopy and morphology.

Science.gov (United States)

Schulz, Sissy-Amelie; Wöhler, Aliona; Beutner, Dirk; Angelov, Doychin N

2016-03-01

The human glomus caroticum (GC) is not readily accessible during ordinary anatomical teaching courses because of insufficient time and difficulties encountered in the preparation. Accordingly, most anatomical descriptions of its location, relationship to neighboring structures, size and shape are supported only by drawings, but not by photographs. The aim of this study is to present the GC with all associated roots and branches. Following microscope-assisted dissection and precise photo-documentation, a detailed analysis of location, syntopy and morphology was performed. We carried out this study on 46 bifurcations of the common carotid artery (CCA) into the external (ECA) and internal (ICA) carotid arteries and identified the GC in 40 (91%) of them. We found significant variations regarding the location of the GC and its syntopy: GC was associated with CCA (42%), ECA (28%) and ICA (30%) lying on the medial or lateral surface (82% or 13%, respectively) or exactly in the middle (5%) of the bifurcation. The short and long diameter of its oval form varied from 1.0 × 2.0 to 5.0 × 5.0mm. Connections with the sympathetic trunk (100%), glossopharyngeal (93%), vagus (79%) and hypoglossal nerve (90%) could be established in 29 cadavers. We conclude that precise knowledge of this enormous variety might be very helpful not only to students in medicine and dentistry during anatomical dissection courses, but also to surgeons working in this field. Copyright © 2015 Elsevier GmbH. All rights reserved.

Effects of water stress, organic amendment and mycorrhizal inoculation on soil microbial community structure and activity during the establishment of two heavy metal-tolerant native plant species.

Science.gov (United States)

Fernández, D A; Roldán, A; Azcón, R; Caravaca, F; Bååth, E

2012-05-01

Our aim was to examine the effect of water stress on plant growth and development of two native plant species (Tetraclinis articulata and Crithmum maritimum) and on microbial community composition and activity in the rhizosphere soil, following the addition of an organic amendment, namely sugar beet residue (SBR), and/or the inoculation with an arbuscular mycorrhizal (AM) fungus, namely Glomus mosseae, in a non-sterile heavy metal-polluted soil. The AM inoculation did not have any significant effect on plant growth of both species. In T. articulata, SBR increased shoot growth, foliar P, total phospholipid fatty acids (PLFA), fungi-related PLFA, AM fungi-related neutral lipid fatty acid, bacterial gram-positive/gram-negative PLFA ratio and the β-glucosidase and dehydrogenase activities. SBR and AM inoculation increased phosphatase activity in T. articulata plants grown under drought conditions. In both plants, there was a synergistic effect between AM inoculation and SBR on mycorrhizal colonisation under drought conditions. In C. maritimum, the increase produced by the SBR on total amounts of PLFA, bacterial gram-positive-related PLFA and bacterial gram-negative-related PLFA was considerably higher under drought conditions. Our results suggest that the effectiveness of the amendment with regard to stimulating microbial communities and plant growth was largely limited by drought, particularly for plant species with a low degree of mycorrhizal colonisation.

The role of glomalin, a protein produced by arbuscular mycorrhizal fungi, in sequestering potentially toxic elements

Energy Technology Data Exchange (ETDEWEB)

Gonzalez-Chavez, M.C.; Carrillo-Gonzalez, R.; Wright, S.F.; Nichols, K.A

2004-08-01

Naturally occurring soil organic compounds stabilize potentially toxic elements (PTEs) such as Cu, Cd, Pb, and Mn. The hypothesis of this work was that an insoluble glycoprotein, glomalin, produced in copious amounts on hyphae of arbuscular mycorrhizal fungi (AMF) sequesters PTEs. Glomalin can be extracted from laboratory cultures of AMF and from soils. Three different experiments were conducted. Experiment 1 showed that glomalin extracted from two polluted soils contained 1.6-4.3 mg Cu, 0.02-0.08 mg Cd, and 0.62-1.12 mg Pb/g glomalin. Experiment 2 showed that glomalin from hyphae of an isolate of Gigaspora rosea sequestered up to 28 mg Cu/g in vitro. Experiment 3 tested in vivo differences in Cu sequestration by Cu-tolerant and non-tolerant isolates of Glomus mosseae colonizing sorghum. Plants were fed with nutrient solution containing 0.5, 10 or 20 {mu}M of Cu. Although no differences between isolates were detected, mean values for the 20 {mu}M Cu level were 1.6, 0.4, and 0.3 mg Cu/g for glomalin extracted from hyphae, from sand after removal of hyphae and from hyphae attached to roots, respectively. Glomalin should be considered for biostabilization leading to remediation of polluted soils. - Glomalin may be useful in remediation of toxic elements in soils.

The role of glomalin, a protein produced by arbuscular mycorrhizal fungi, in sequestering potentially toxic elements

International Nuclear Information System (INIS)

Gonzalez-Chavez, M.C.; Carrillo-Gonzalez, R.; Wright, S.F.; Nichols, K.A.

2004-01-01

Naturally occurring soil organic compounds stabilize potentially toxic elements (PTEs) such as Cu, Cd, Pb, and Mn. The hypothesis of this work was that an insoluble glycoprotein, glomalin, produced in copious amounts on hyphae of arbuscular mycorrhizal fungi (AMF) sequesters PTEs. Glomalin can be extracted from laboratory cultures of AMF and from soils. Three different experiments were conducted. Experiment 1 showed that glomalin extracted from two polluted soils contained 1.6-4.3 mg Cu, 0.02-0.08 mg Cd, and 0.62-1.12 mg Pb/g glomalin. Experiment 2 showed that glomalin from hyphae of an isolate of Gigaspora rosea sequestered up to 28 mg Cu/g in vitro. Experiment 3 tested in vivo differences in Cu sequestration by Cu-tolerant and non-tolerant isolates of Glomus mosseae colonizing sorghum. Plants were fed with nutrient solution containing 0.5, 10 or 20 μM of Cu. Although no differences between isolates were detected, mean values for the 20 μM Cu level were 1.6, 0.4, and 0.3 mg Cu/g for glomalin extracted from hyphae, from sand after removal of hyphae and from hyphae attached to roots, respectively. Glomalin should be considered for biostabilization leading to remediation of polluted soils. - Glomalin may be useful in remediation of toxic elements in soils

Co-inoculation of arbusculr mycorrhizae and nitrogen fixing bacteria enhance alfalfa yield under saline conditions

International Nuclear Information System (INIS)

Zhu, R.; Tang, F.; Liu, F.; Chen, J.

2016-01-01

The study was to investigate the effects of combined inoculation of Glomus mosseae (arbusculr mycorrhizae fungi, AMF) and Sinorhizobium meliloti (nitrogen-fixing bacteria, i.e., an Rhizobium meliloti, RM) on yield, nutrient contents, nodulation and mycorrhizal colonization of different alfalfa cultivars under saline conditions. An experiment was conducted to test the efficacy of AMF and RM inoculation in development of salt tolerance in alfalfa cultivars (Zhaodong, Nongjing and Longmu) under different salinity levels (0, 60, 120 and 180 mM NaCl). We found that under non stress condition, double inoculation of alfalfa with rhizobium and AM increased the alfalfa yield, nodule weight and number, as well as shoot proline contents, the most when plants were double inoculated followed by AM and rhizobium inoculation, respectively. Whereas under salinity condition, double inoculation of alfalfa with rhizobium and AM increased alfalfa yield, mycorrhizal infection, nodule weight and number as well as increased in shoot proline content, the most followed by AM and rhizobium inoculation, respectively. The Results suggest that growth of alfalfa may be improved by combined inoculation of alfalfa with AM and rhizobium under salt and non-stress conditions. Alleviation of alfalfa growth under saline condition was perhaps due to an increase in mycorrhizal infection and nodule weight and number as well as an increased in shoot proline content by dual inoculation. (author)

Reducing nitrogen runoff from paddy fields with arbuscular mycorrhizal fungi under different fertilizer regimes.

Science.gov (United States)

Zhang, Shujuan; Wang, Li; Ma, Fang; Zhang, Xue; Fu, Dafang

2016-08-01

Nitrogen (N) runoff from paddy fields serves as one of the main sources of water pollution. Our aim was to reduce N runoff from paddy fields by fertilizer management and inoculation with arbuscular mycorrhizal fungi (AMF). In northeast China, Shuangcheng city in Heilongjiang province, a field experiment was conducted, using rice provided with 0%, 20%, 40%, 60%, 80%, and 100% of the local norm of fertilization (including N, phosphorus and potassium), with or without inoculation with Glomus mosseae. The volume, concentrations of total N (TN), dissolved N (DN) and particulate N (PN) of runoff water were measured. We found that the local norm of fertilization led to 18.9kg/ha of N runoff during rice growing season, with DN accounting for 60%-70%. We also found that reduction in fertilization by 20% cut down TN runoff by 8.2% while AMF inoculation decreased N runoff at each fertilizer level and this effect was inhibited by high fertilization. The combination of inoculation with AMF and 80% of the local norm of fertilization was observed to reduce N runoff by 27.2%. Conclusively, we suggested that the contribution of AMF inoculation combined with decreasing fertilization should get more attention to slow down water eutrophication by reducing N runoff from paddy fields. Copyright © 2016. Published by Elsevier B.V.

Dual inoculation with mycorrhizal and saprotrophic fungi applicable in sustainable cultivation improves the yield and nutritive value of onion.

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Albrechtova, Jana; Latr, Ales; Nedorost, Ludovit; Pokluda, Robert; Posta, Katalin; Vosatka, Miroslav

2012-01-01

The aim of this paper was to test the use of dual microbial inoculation with mycorrhizal and saprotrophic fungi in onion cultivation to enhance yield while maintaining or improving the nutritional quality of onion bulbs. Treatments were two-factorial: (1) arbuscular mycorrhizal fungi (AMF): the mix corresponding to fungal part of commercial product Symbivit (Glomus etunicatum, G. microaggregatum, G. intraradices, G. claroideum, G. mosseae, and G. geosporum) (M1) or the single-fungus inoculum of G. intraradices BEG140 (M2) and (2) bark chips preinoculated with saprotrophic fungi (mix of Gymnopilus sp., Agrocybe praecox, and Marasmius androsaceus) (S). The growth response of onion was the highest for the M1 mix treatment, reaching nearly 100% increase in bulb fresh weight. The effectiveness of dual inoculation was proved by more than 50% increase. We observed a strong correlation (r = 0.83) between the growth response of onion bulbs and AM colonization. All inoculation treatments but the single-fungus one enhanced significantly the total antioxidant capacity of bulb biomass, was the highest values being found for M1, S + M1, and S + M2. We observed some induced enhancement of the contents of mineral elements in bulb tissue (Mg and K contents for the M2 and M2, S, and S + M2 treatments, resp.).

Dual Inoculation with Mycorrhizal and Saprotrophic Fungi Applicable in Sustainable Cultivation Improves the Yield and Nutritive Value of Onion

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Jana Albrechtova

2012-01-01

Full Text Available The aim of this paper was to test the use of dual microbial inoculation with mycorrhizal and saprotrophic fungi in onion cultivation to enhance yield while maintaining or improving the nutritional quality of onion bulbs. Treatments were two-factorial: (1 arbuscular mycorrhizal fungi (AMF: the mix corresponding to fungal part of commercial product Symbivit (Glomus etunicatum, G. microaggregatum, G. intraradices, G. claroideum, G. mosseae, and G. geosporum (M1 or the single-fungus inoculum of G. intraradices BEG140 (M2 and (2 bark chips preinoculated with saprotrophic fungi (mix of Gymnopilus sp., Agrocybe praecox, and Marasmius androsaceus (S. The growth response of onion was the highest for the M1 mix treatment, reaching nearly 100% increase in bulb fresh weight. The effectiveness of dual inoculation was proved by more than 50% increase. We observed a strong correlation (r=0.83 between the growth response of onion bulbs and AM colonization. All inoculation treatments but the single-fungus one enhanced significantly the total antioxidant capacity of bulb biomass, was the highest values being found for M1, S + M1, and S + M2. We observed some induced enhancement of the contents of mineral elements in bulb tissue (Mg and K contents for the M2 and M2, S, and S+M2 treatments, resp..

Respiration of the external mycelium in the arbuscular mycorrhizal symbiosis shows strong dependence on recent photosynthates and acclimation to temperature.

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Heinemeyer, A; Ineson, P; Ostle, N; Fitter, A H

2006-01-01

* Although arbuscular mycorrhizal (AM) fungi are a major pathway in the global carbon cycle, their basic biology and, in particular, their respiratory response to temperature remain obscure. * A pulse label of the stable isotope (13)C was applied to Plantago lanceolata, either uninoculated or inoculated with the AM fungus Glomus mosseae. The extra-radical mycelium (ERM) of the fungus was allowed to grow into a separate hyphal compartment excluding roots. We determined the carbon costs of the ERM and tested for a direct temperature effect on its respiration by measuring total carbon and the (13)C:(12)C ratio of respired CO(2). With a second pulse we tested for acclimation of ERM respiration after 2 wk of soil warming. * Root colonization remained unchanged between the two pulses but warming the hyphal compartment increased ERM length. delta(13)C signals peaked within the first 10 h and were higher in mycorrhizal treatments. The concentration of CO(2) in the gas samples fluctuated diurnally and was highest in the mycorrhizal treatments but was unaffected by temperature. Heating increased ERM respiration only after the first pulse and reduced specific ERM respiration rates after the second pulse; however, both pulses strongly depended on radiation flux. * The results indicate a fast ERM acclimation to temperature, and that light is the key factor controlling carbon allocation to the fungus.

Interplant communication of tomato plants through underground common mycorrhizal networks.

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Song, Yuan Yuan; Zeng, Ren Sen; Xu, Jian Feng; Li, Jun; Shen, Xiang; Yihdego, Woldemariam Gebrehiwot

2010-10-13

Plants can defend themselves to pathogen and herbivore attack by responding to chemical signals that are emitted by attacked plants. It is well established that such signals can be transferred through the air. In theory, plants can also communicate with each other through underground common mycorrhizal networks (CMNs) that interconnect roots of multiple plants. However, until now research focused on plant-to-plant carbon nutrient movement and there is no evidence that defense signals can be exchanged through such mycorrhizal hyphal networks. Here, we show that CMNs mediate plant-plant communication between healthy plants and pathogen-infected tomato plants (Lycopersicon esculentum Mill.). After establishment of CMNs with the arbuscular mycorrhizal fungus Glomus mosseae between tomato plants, inoculation of 'donor' plants with the pathogen Alternaria solani led to increases in disease resistance and activities of the putative defensive enzymes, peroxidase, polyphenol oxidase, chitinase, β-1,3-glucanase, phenylalanine ammonia-lyase and lipoxygenase in healthy neighbouring 'receiver' plants. The uninfected 'receiver' plants also activated six defence-related genes when CMNs connected 'donor' plants challenged with A. solani. This finding indicates that CMNs may function as a plant-plant underground communication conduit whereby disease resistance and induced defence signals can be transferred between the healthy and pathogen-infected neighbouring plants, suggesting that plants can 'eavesdrop' on defence signals from the pathogen-challenged neighbours through CMNs to activate defences before being attacked themselves.

CRESCIMENTO, ACÚMULO DE NUTRIENTES E FENÓIS TOTAIS DE MUDAS DE CEDROAUSTRALIANO (Toona ciliata INOCULADAS COM FUNGOS MICORRÍZICOS

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Késsia Barreto Lima

2015-01-01

Full Text Available This study aimed to evaluate the Australian red cedar seedlings for their ability to growth, nutrition and production of phenolic compounds under arbuscular mycorrhizal fungi (AMF inoculation. An experiment was carried out under greenhouse conditions, with three treatments consisting of Gigaspora margarita, Glomus etunicatum, Glomus clarum in single inoculation, and four treatments composed by the combination of these species, Gigaspora margarita + Glomus clarum, Gigaspora margarita + Glomus etunicatum, Glomus clarum + Glomus etunicatum and Gigaspora margarita + Glomus etunicatum + Glomus clarum. All treatments with the fungal inoculum were evaluated without addition of phosphorus in the substrate. In comparison, three treatment controls were used (without fungus containing in random blocks with five replicates. After 140 days of germination, it was observed that all species of AMF inoculated alone or in combination, led to significant benefits on growth, nutrition and production of phenolic compounds in Australian red cedar seedlings in soils containing low phosphorus availability. The mixture in the soil of Gigaspora margarita, Glomus etunicatum and Glomus clarum was able to provide significant increases in plant growth in most parameters assessed, resulting in performance equivalent or higher than non-mycorrhizal and control plants grown in soil fertilized with phosphorus. This suggests that AMF can promote reduction in phosphorus addition during the production of Australian red cedar seedlings.

Biostimulation of inoculation with Glomus proliferum and application of humic acid in the in vitro growth of Lunularia cruciata

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Camila Pinheiro Nobre

2013-12-01

Full Text Available In this study, we evaluated the growth of the liverwort Lunularia cruciata, inoculated or not with the arbuscular mycorrhizal fungi (AMF Glomus proliferum (15 spores per Petri dish, in Strullu-Romand Variant (SRV medium modified and enriched with humic acid (HA at different concentrations (0, 20, 40 and 80 mg C L−1, as well as the sporulation of the AMF. We assessed the absolute growth rate (AGR and relative growth rate (RGR at inoculation, as well as at 7, 14, 21, 28, 43, 52 and 60 days after inoculation (DAI, whereas we assessed sporulation at 25, 43, 60 and 70 DAI. The main determinant of L. cruciata growth was the presence of AMF. With and without G. proliferum inoculation, respectively, the AGR peaked at 39 and 42 DAI, and the RGR was 0.0474 and 0.0387 cm² cm−2 d−1. Doses of 20 and 80 mg C L−1 of HA had a positive influence on the growth of L. cruciata. With and without HA, respectively, the AGR peaked at 38 and 39 DAI, and the RGR was 0.0484 and 0.0422 cm² cm−2 d−1. The sporulation of G. proliferum, which was as high as 199 spores plate−1, was influenced by HA, especially at 20 and 80 mg C L−1.

Integrated multi-omics analysis supports role of lysophosphatidylcholine and related glycerophospholipids in the Lotus japonicus-Glomus intraradices mycorrhizal symbiosis.

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Vijayakumar, Vinod; Liebisch, Gerhard; Buer, Benjamin; Xue, Li; Gerlach, Nina; Blau, Samira; Schmitz, Jessica; Bucher, Marcel

2016-02-01

Interaction of plant roots with arbuscular mycorrhizal fungi (AMF) is a complex trait resulting in cooperative interactions among the two symbionts including bidirectional exchange of resources. To study arbuscular mycorrhizal symbiosis (AMS) trait variation in the model plant Lotus japonicus, we performed an integrated multi-omics analysis with a focus on plant and fungal phospholipid (PL) metabolism and biological significance of lysophosphatidylcholine (LPC). Our results support the role of LPC as a bioactive compound eliciting cellular and molecular response mechanisms in Lotus. Evidence is provided for large interspecific chemical diversity of LPC species among mycorrhizae with related AMF species. Lipid, gene expression and elemental profiling emphasize the Lotus-Glomus intraradices interaction as distinct from other arbuscular mycorrhizal (AM) interactions. In G. intraradices, genes involved in fatty acid (FA) elongation and biosynthesis of unsaturated FAs were enhanced, while in Lotus, FA synthesis genes were up-regulated during AMS. Furthermore, FAS protein localization to mitochondria suggests FA biosynthesis and elongation may also occur in AMF. Our results suggest the existence of interspecific partitioning of PL resources for generation of LPC and novel candidate bioactive PLs in the Lotus-G. intraradices symbiosis. Moreover, the data advocate research with phylogenetically diverse Glomeromycota species for a broader understanding of the molecular underpinnings of AMS. © 2015 John Wiley & Sons Ltd.

Interactions between the arbuscular mycorrhizal (AM) fungus Glomus intraradices and nontransformed tomato roots of either wild-type or AM-defective phenotypes in monoxenic cultures.

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Bago, Alberto; Cano, Custodia; Toussaint, Jean-Patrick; Smith, Sally; Dickson, Sandy

2006-09-01

Monoxenic symbioses between the arbuscular mycorrhizal (AM) fungus Glomus intraradices and two nontransformed tomato root organ cultures (ROCs) were established. Wild-type tomato ROC from cultivar "RioGrande 76R" was employed as a control for mycorrhizal colonization and compared with its mutant line (rmc), which exhibits a highly reduced mycorrhizal colonization (rmc) phenotype. Structural features of the two root lines were similar when grown either in soil or under in vitro conditions, indicating that neither monoxenic culturing nor the rmc mutation affected root development or behavior. Colonization by G. intraradices in monoxenic culture of the wild-type line was low (<10%) but supported extensive development of extraradical mycelium, branched absorbing structures, and spores. The reduced colonization of rmc under monoxenic conditions (0.6%) was similar to that observed previously in soil. Extraradical development of runner hyphae was low and proportional to internal colonization. Few spores were produced. These results might suggest that carbon transfer may be modified in the rmc mutant. Our results support the usefulness of monoxenically obtained mycorrhizas for investigation of AM colonization and intraradical symbiotic functioning.

Comparative potentials of native arbuscular mycorrhizal fungi to improve nutrient uptake and biomass of Sorghum bicolor Linn

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Pattarawadee Sumthong Nakmee

2016-05-01

Full Text Available Sorghum (Sorghum bicolor Linn. seedlings were grown in pots using Pakchong soil from Nakhon Ratchasima province. Ten species of native Arbuscular mycorrhizal (AM fungi: Glomus sp. 1, Glomus sp. 2, Glomus sp. 3, Glomus aggregatum, Glomus fasciculatum, Acaulospora longula, Glomus occultum, Acaulospora scrobiculata, Acaulospora spinosa and Scutellospora sp., were used to inoculate sorghum seedlings. The sorghum growth and uptake of several major nutrients were evaluated at the harvesting stage. The results revealed that sorghum inoculated with A. scrobiculata produced the greatest biomass, grain dry weight and total nitrogen uptake in shoots. The highest phosphorus uptake in shoots was found in A. spinosa-inoculated plants, followed by Glomus sp. and A. scrobiculata, whereas Scutellospora sp.-inoculated plants showed the highest potassium uptake in shoots followed by A. scrobiculata. Overall, the most efficient AM fungi for improvement of nutrient uptake, biomass and grain dry weight in sorghum were A. scrobiculata.

Primary glomangiosarcoma of the lung: A case report

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Konstantinou Eleftheria

2010-10-01

Full Text Available Abstract Background Glomus tumor is an uncommon neoplasm derived from cells of the neuromyoarterial glomus or glomus body. Most glomus tumours occur in the dermis and subcutaneous tissues. A case of a primary pulmonary glomus tumour originating in the right upper lobe is presented. Case presentation A 74-yr-old male was admitted with siccus cough, dyspnea and right-sided chest pain. Computed tomography of the thorax revealed a 4 cm growth of the right upper lobe. Fiberoptic bronchoscopy demonstrated an endobronchial hypervascular mass causing obstruction of the apical segmental bronchus. Pathology report was consistent with pulmonary glomus tumor. The patient underwent a typical right upper lobectomy with mediastinal lymph node dissection. Twelve months later he is free of disease. Conclusion Occasionally glomus tumors can occur in extracutaneous sites such as the gastrointestinal tract, bone, genitourinary system and respiratory tract. Primary pulmonary glomus tumors are very rare (our case is the 19th one presented in the international literature and are often confused with other solid neoplasms such as carcinoids, hemangiopericytomas and tumors belonging to the family of Ewing's sarcoma/primitive neuroectodermal tumours.

The Effects of Soil Amendments and Bio-fertilizers Inoculation on Morphological Characteristics and Yield of Echium amoenum

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M.B. Amiri

2017-10-01

one of the most important medicinal plants in Iranian traditional medicine. Petals of Iranian oxtongue have been advocated for a variety of effects such as demulcent, anti-inflammatory and analgesic, especially for common cold, anxiolytic, sedative and other psychiatric symptoms including obsession in folk medicine of Iran. Despite many research on the effects of organic acids and bio-fertilizers on different crops, there is scarce information on the effects of these factors for many medicinal plants. Therefore, in this study effect of organic acids and bio-fertilizers on morphological characteristics and yield of Echium amoenum in a low input cropping system was studied. Materials and methods: In order to evaluate the effects of soil amendments and different bio-fertilizers on morphological characteristics and seed yield of Echium amoenum, an experiment was conducted based on randomized complete block design with three replications during 2011-2013 growing seasons, at the Research Farm of Ferdowsi University of Mashhad, Iran. Treatments were eight different types of soil amendments and bio-fertilizers concluding: 1 Humic acid, 2 Fulvic acid, 3 Nitroxin® (Azotobacter spp. and Azospirillum spp., 4 Biophosphorous® (Bacillus sp. and Pseudomonas sp., 5 Biosulfur® (Thiobacillus spp., 6 Mycorrhiza (Glomus mosseae, 7 Mycorrhiza (Glomus intraradices, and 8 no fertilizer as control. Result and Discussion: The results showed that mycorrhiza species increased flower yield compared with control, as the flower yield in treatments of G. mosseae and G. intraradices were 24 and 11 percent more than control, respectively. Soil amendments and different bio-fertilizers increased the number of flower cycle per plant compared with control. Although the effect of biophosphorous® was more pronounced, as the number of flower cycle per plant increased from 342 to 1322 cycles in control and biophosphorous® , respectively. Humic acid treatment increased seed yield, biological yield, seed

Diagnóstico do tumor glômico pela dermatoscopia do leito e da matriz ungueal Diagnosis of glomus tumor by nail bed and matrix dermoscopy

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Laura de Sena Nogueir Maehara

2010-04-01

Full Text Available A cirurgia é o tratamento definitivo para os tumores glômicos. Algumas vezes, esse procedimento pode representar um desafio, pois, apesar de ser um tumor bem delimitado, a sua visualização pode ser difícil. O uso da dermatoscopia do leito e da matriz ungueal facilita o diagnóstico e auxilia a localização e delimitação do tumor. Trata-se de método simples e de baixo custo que não implica risco adicional ao paciente que irá se submeter a um procedimento cirúrgico.Surgery is the best treatment for glomus tumors. Sometimes this can be a challenging procedure because, despite being a well-defined tumor, its visualization can be difficult. The use of nail bed and matrix dermoscopy facilitates the diagnosis and aids in the localization and demarcation of the tumor. It is a simple and low-cost procedure that does not involve additional risks to the patient who will undergo surgery.

Effect of arbuscular mycorrhizal fungi on trace metal uptake by sunflower plants grown on cadmium contaminated soil.

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Hassan, Saad Eldin; Hijri, Mohamed; St-Arnaud, Marc

2013-09-25

Trace metal (TM) pollution of soil is a worldwide problem that threatens the quality of human and environmental health. Phytoremediation using plants and their associated microbes has been increasingly used as a green technology for cleaning up TM-polluted soils. In this study, we investigated the effect of inoculating two arbuscular mycorrhizal fungal isolates, Rhizophagus irregularis and Funneliformis mosseae, on trace metal uptake by sunflower plants grown in soils contaminated with three different Cd concentrations in a greenhouse trial. Root colonization, plant dry mass, and plant tissue cadmium (Cd), zinc (Zn), and copper (Cu) concentrations in roots and shoots were determined after sunflower harvesting. We found that root mycorrhizal colonization rates were not significantly affected by Cd treatments. At low soil Cd concentration, R. irregularis-inoculated plants had significantly higher shoot Cd and Zn concentrations than plants inoculated with F. mosseae and non-inoculated plants. However, at high soil Cd concentrations, F. mosseae-inoculated plants had significantly lower shoot Cd and Zn concentrations and biological concentration factor (BCF) values than plants inoculated with R. irregularis and non-inoculated plants. Cadmium was mainly translocated in shoot tissues of R. irregularis-inoculated plants and sequestered in the rhizosphere of F. mosseae-inoculated plants. The results indicate that these AMF strains mediate different tolerance strategies to alleviate TM toxicity in their host plants and that inoculation with the R. irregularis strain can be used for Cd phytoextraction, whereas this F. mosseae strain can be useful for Cd and Zn phytostabilization of contaminated soil. Copyright © 2013 Elsevier B.V. All rights reserved.

Inoculation with arbuscular mycorrhizal fungi and addition of composted olive-mill waste enhance plant establishment and soil properties in the regeneration of a heavy metal-polluted environment.

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Curaqueo, Gustavo; Schoebitz, Mauricio; Borie, Fernando; Caravaca, Fuensanta; Roldán, Antonio

2014-06-01

A greenhouse experiment was carried out in order to investigate the effects of arbuscular mycorrhizal (AM) fungi inoculation and the use of composted olive waste (COW) in the establishment of Tetraclinis articulata and soil properties in a heavy metal-polluted soil. The treatments assayed were as follows: AM + 0% COW, AM + 1% COW, and AM + 3% COW. The higher doses of COW in combination with AM fungi increased shoot and root biomass production of T. articulata by 96 and 60%, respectively. These treatments trended to improve the soil properties evaluated, highlighting the C compounds and N as well as the microbiological activities. In relation to the metal translocation in T. articulata, doses of COW applied decreased the Cr, Ni, and Pb contents in shoot, as well as Cr and As in root, although the most of them reached low levels and far from phytotoxic. The COW amendment aided Glomus mosseae-inoculated T. articulata plants to thrive in contaminated soil, mainly through an improvement in both nutrients uptake, mainly P and soil microbial function. In addition, the combined use of AM fungi plus COW could be a feasible strategy to be incorporated in phytoremediation programs because it promotes soil properties, a better performance of plants for supporting the stress in heavy metal-contaminated soils derived from the mining process, and also can be a good way for olive-mill waste disposal.

Selenium bioavailability and uptake as affected by four different plants in a loamy clay soil with particular attention to mycorrhizae inoculated ryegrass

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Munier-Lamy, C.; Deneux-Mustin, S.; Mustin, C.; Merlet, D.; Berthelin, J.; Leyval, C.

2007-01-01

The aim of this study was to investigate the influence of plant species, especially of their rhizosphere soil, and of inoculation with an arbuscular mycorrhizal (AM) fungus on the bioavailability of selenium and its transfer in soil-plant systems. A pot experiment was performed with a loamy clay soil and four plant species: maize, lettuce, radish and ryegrass, the last one being inoculated or not with an arbuscular mycorrhizal fungus (Glomus mosseae). Plant biomass and Se concentration in shoots and roots were estimated at harvest. Se bioavailability in rhizosphere and unplanted soil was evaluated using sequential extractions. Plant biomass and selenium uptake varied with plant species. The quantity of rhizosphere soil also differed between plants and was not proportional to plant biomass. The highest plant biomass, Se concentration in plants, and soil to plant transfer factor were obtained with radish. The lowest Se transfer factors were obtained with ryegrass. For the latter, mycorrhizal inoculation did not significantly affect plant growth, but reduced selenium transfer from soil to plant by 30%. In unplanted soil after 65 days aging, more than 90% of added Se was water-extractable. On the contrary, Se concentration in water extracts of rhizosphere soil represented less than 1% and 20% of added Se for ryegrass and maize, respectively. No correlation was found between the water-extractable fraction and Se concentration in plants. The speciation of selenium in the water extracts indicated that selenate was reduced, may be under organic forms, in the rhizosphere soil

Arbuscular mycorrhizal fungi associated with psammophilic vegetation in Mediterranean coastal sand dunes

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Camprubi, A.; Calvet, C.; Cabot, P.; Pitet, M.; Estaun, V.

2010-07-01

This study was conducted in order to characterize the natural albacore's mycorrhizal (AM) biodiversity from Mediterranean sand dune ecosystems and to protect in a collection this biodiversity. The occurrence of AM fungi associated with sand dune plant species in three Mediterranean locations on the north-eastern coast of Spain was examined in one well preserved coastal sand dune and in two embrionary dunes recently protected from public access. Traditional taxonomy and molecular techniques were used to identify the AM fungal species present in these ecosystems. The species identified and isolated were: Scutellospora persica (Kiosk and Walker) Walker and Sanders, Glomus ambisporum Smith and Schenck, Glomus diaphanum Morton and Walker, Glomus clarum Nicolson and Schenck, Glomus intraradices Schenck and Smith, Glomus microaggregatum Koske, Gemma and Olexia and Gigaspora margarita Becker and Hall. Spores of Glomus were the most abundant in the direct soil extraction samples. The molecular analysis indicates that the most abundant fungi forming AM in the roots belonged to the Gigasporaceae group followed by fungi of Glomus group A and Glomus group B. The highest diversity of fungi and abundance of the AM fungal spores was found in the well preserved and undisturbed dune systems. (Author) 26 refs.

Radiation therapy for glomus tumors of the temporal bone; Tratamento radioterapico dos tumores glomicos do osso temporal

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Dall' Igna, Celso; Antunes, Marcelo B [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Hospital das Clinicas. Servico de Otorrinolaringologia e Cirurgia da Cabeca e Pescoco; Dall' Igna, Daniela Pernigotti [Parana Univ., Curitiba, PR (Brazil)

2005-11-15

The treatment of glomic tumors has been controversial since its first description. It can be done with surgery, radiotherapy or just expectation. Aim: the objective of this paper was to evaluate the effectiveness and complications of radiotherapy.Study Design: clinical with transversal cohort. Material and method: it was made a retrospective review in the charts of the patients with glomus jugular tumors treated with radiotherapy. Disease control was determined by (1) no progression of symptoms or cranial nerve dysfunction or (2) no progression of the lesion in radiological follow-up. It was also evaluated the follow-up period and the sequelae of the treatment. Results: twelve patients were included, 8 of then women. The follow-up period was from 3 to 35 years, with a media of 11,6 years. The main symptoms were: hearing loss, pulsate tinnitus, dizziness and vertigo. The signs were pulsate retrotympanic mass, facial palsy and cofosis. The tumors were staged using Fischs classification. The radiotherapy was performed with linear accelerator with dose ranging from 4500-5500 in 4-6 weeks. In the follow-up period were possible to identify sequelaes like dermatitis, meatal stenosis, cofosis and facial palsy. Discussion: the signs and symptoms were the same found in the medical literature. The type and dosages of the radiotherapy were also the same of others reports. All patients had improvement of the symptoms and only one was not considered as having disease controlled. Complications were, in general, minor complications, with exception of the cofosis and facial palsy. Conclusion: radiotherapy is a viable alternative to treatment of these tumors because their good response and low level of complications. It should be considered specially in advanced tumors where a surgical procedure could bring a high level of morbidity. (author)

Effect of Mycorrhiza Symbiosis on Yield, Yield Components and Water Use Efficiency of Sesame (Sesamum indicum L. Affected by Different Irrigation Regimes in Mashhad Condition

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A Koocheki

2016-02-01

4000 m3 ha-1, inoculation with two species of mycorrhiza fungi (Glomus mosseae and G. intraradices and control allocated to the main and sub plots, respectively. Results and Discussion Results showed that the effect of irrigation regimes were significant (p≤0.05 on yield components except 1000-seed weight, biological yield, seed yield, harvest index (HI and WUE based on biological yield and seed yield. By increasing the irrigation level from 2000 to 4000 m3 ha-1 biological and seed yield enhanced up to 52% and 118%, respectively. Increasing the irrigation level from 2000 to 4000 m3 ha-1 also improved WUE based on seed yield up to 22%. Inoculation with mycorrhiza species had significant effect on yield components, biological yield, seed yield, HI and WUE based on biological yield and seed yield P ≤ 0.05. Inoculation with G. mosseae improved seed yield compared to G. intraradices and control with 7 and 12%, respectively. These improvement of WUE based on seed yield were 7% and 24%, respectively. In general, mycorrhiza inoculation enhanced WUE through root system development and nutrient availability as this effect for G. mosseae was higher than G. intraradices. Conclusions Yield and yield components of sesame were generally more responsive to irrigation level under mycorhiza inoculation. Sesame yield and its components were significantly affected by irrigation treatments. Increase the irrigation level enhanced biological and seed yield- and also improved WUE. The water was used more efficiently in the deficit irrigation treatments where WUE increased with lower amounts of water. Inoculation with G. mosseae improved seed yield compared to G. intraradices and control. Mycorrhiza inoculation enhanced WUE due to root system development and nutrient availability. These results highlight the importance of determining the interaction effects between water level and mycorrhiza inoculation on yield of sesame to formulate proper management practices for sustainable production.

Variations in water status, gas exchange, and growth in Rosmarinus officinalis plants infected with Glomus deserticola under drought conditions.

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Sánchez-Blanco, Ma Jesús; Ferrández, Trinitario; Morales, Ma Angeles; Morte, Asunción; Alarcón, Juan José

2004-06-01

The influence of the arbuscular mycorrhizal fungus Glomus deserticola on the water relations, gas exchange parameters, and vegetative growth of Rosmarinus officinalis plants under water stress was studied. Plants were grown with and without the mycorrhizal fungus under glasshouse conditions and subjected to water stress by withholding irrigation water for 14 days. Along the experimental period, a significant effect of the fungus on the plant growth was observed, and under water stress, mycorrhizal plants showed an increase in aerial and root biomass compared to non-mycorrhizal plants. The decrease in the soil water potential generated a decrease in leaf water potential (psi(l)) and stem water potential (psi(x)) of mycorrhizal and non-mycorrhizal plants, with this decrease being lower in mycorrhizal water-stressed plants. Mycorrhization also had positive effects on the root hydraulic conductivity (Lp) of water stressed plants. Furthermore, mycorrhizal-stressed plants showed a more important decrease in osmotic potential at full turgor (psi(os)) than did non-mycorrhizal-stressed plants, indicating the capacity of osmotic adjustment. Mycorrhizal infection also improved photosynthetic activity (Pn) and stomatal conductance (g(s)) in plants under water stress compared to the non-mycorrhizal-stressed plants. A similar behaviour was observed in the photochemical efficiency of PSII (Fv/Fm) with this parameter being lower in non-mycorrhizal plants than in mycorrhizal plants under water stress conditions. In the same way, under water restriction, mycorrhizal plants showed higher values of chlorophyll content than did non-mycorrhizal plants. Thus, the results obtained indicated that the mycorrhizal symbiosis had a beneficial effect on the water status and growth of Rosmarinus officinalis plants under water-stress conditions.

Contaminação do solo com antraceno e creosoto e o crescimento vegetal e a colonização micorrízica pelo Glomus etunicatum Soil contamination with anthracene and creosote: impact on plant growth and mycorrhizal colonization by Glomus etunicatum

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Alessandra Monteiro de Paula

2007-08-01

Full Text Available A contaminação do solo por compostos orgânicos, especialmente os hidrocarbonetos aromáticos policíclicos (HAPs de petróleo, é um problema crescente e que traz graves conseqüências ambientais. Para avaliar os impactos causados por esses compostos, torna-se necessário conhecer seus efeitos sobre as plantas e a microbiota rizosférica associada. No presente estudo avaliaram-se os efeitos de antraceno e creosoto no crescimento e na colonização micorrízica de Brachiaria brizantha e Pueraria phaseoloides. Antraceno e creosoto foram aplicados a um solo infestado com o fungo micorrízico Glomus etunicatum, sendo: antraceno nas concentrações de 0; 0,25; 0,5; 0,75 e 1 g kg-1 solo; e creosoto nas concentrações de 0; 0,5; 1; 2 e 3 g kg-1 solo. O solo com os tratamentos foi colocado em tubetes (290 cm³ e semeado com as plantas-teste, as quais foram cultivadas por seis semanas. Verificou-se que o antraceno não afetou o crescimento da puerária e teve pequeno estímulo no crescimento da braquiária na dose mais baixa, enquanto o creosoto reduziu o crescimento da braquiária e não teve efeito na puerária. Entretanto, ambos os contaminantes inibiram a colonização micorrízica da puerária, atingindo redução de cerca de 90 % em relação ao controle. Em concentrações bem inferiores às encontradas em solos contaminados, a colonização micorrízica foi inibida em 50 %, ficando evidente o potencial de impacto desses poluentes na relação planta-fungo micorrízico. Na braquiária não foi encontrada colonização micorrízica. Fica evidenciada a resposta diferenciada das duas espécies estudadas aos contaminantes e o acentuado efeito negativo destes sobre a colonização micorrízica. A puerária, por ter se mostrado insensível aos HAPs, nas concentrações estudadas, apresenta potencial para aplicação na fitorremediação de áreas impactadas por esses contaminantes.Soil contamination by organic compounds, especially by the petroleum

Co-Inoculation Effects of Thiobacillus thiooxidans Bacteria and Mycorrhiza (Glomus spp. on Maize Nutrition at Different Levels of Sulfur

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A. Gholami

2016-02-01

. Inoculation withthesefungihas increased the yield of numerous field-grown crops. This study was aimed to evaluate the effects of thiobacillus bacteria and sulfur application on soil pH, and also their interactions with mycorrhizal fungi in order to improve nutrients uptake and grain yield of maize under alkaline soil condition. Materials and Methods: Treatments arranged as factorial experiment were based on RCBD with three replications. Treatments consisted of mycorrhizal inoculation: inoculated (m1 and non-inoculated (m0, thiobacillus in two levels of inoculated (t1 and non-inoculated (t0 and three levels of sulfur (S0: 0 kg.ha-1, S1: 250 kg.ha-1 and S2: 500 kg.ha-1. Four-row plots were prepared with row width and intra-row space of 60 and 20 cm, respectively. Seeds of maize (Zea Mays, Sc:647 were surface sterilized in a 10% (v/v solution of hydrogen peroxide for 10 min, were rinsed with sterile distilled water. Before sowing, 300 kg of urea per hectare were applied according to the results of soil analysis. In order to facilitate oxidation of sulfur to sulfate form, , S was applied and thoroughly mixed into top 30 cm of soil 30 days before sowing. One week before sowing, thiobacillus (Thiobacillus thiooxidans was inoculated. Inoculum of AM fungus Glomus intraradices, were added to soil just before planting at about 2 centimeters below seed sowing dept. To measure Arbuscular Mycorrhizal colonization, root plants collected one week before harvesting, cleared in 10% KOH at 80˚C for 2 h, and then acidified in 1% HCL for 60 min. Then the cleared roots were stained in a solution of Trypan blue. For nutrient analysis, the following procedure was applied. Zn, Fe, S, and P were determined by Inductively Coupled Plasma-atomic emission spectrometry apparatus. For this purpose, ash of seed samples was prepared at 500-550 degree of Celsius and then 5 ml of HCl 37% was added and with dionized water to reach to 50 ml. Kjeldahl method was used to determine nitrogen. Analysis of variance

Phosphorus supply, arbuscular mycorrhizal fungal species, and plant genotype impact on the protective efficacy of mycorrhizal inoculation against wheat powdery mildew.

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Mustafa, G; Randoux, B; Tisserant, B; Fontaine, J; Magnin-Robert, M; Lounès-Hadj Sahraoui, A; Reignault, Ph

2016-10-01

A potential alternative strategy to chemical control of plant diseases could be the stimulation of plant defense by arbuscular mycorrhizal fungi (AMF). In the present study, the influence of three parameters (phosphorus supply, mycorrhizal inoculation, and wheat cultivar) on AMF protective efficiency against Blumeria graminis f. sp. tritici, responsible for powdery mildew, was investigated under controlled conditions. A 5-fold reduction (P/5) in the level of phosphorus supply commonly recommended for wheat in France improved Funneliformis mosseae colonization and promoted protection against B. graminis f. sp. tritici in a more susceptible wheat cultivar. However, a further decrease in P affected plant growth, even under mycorrhizal conditions. Two commercially available AMF inocula (F. mosseae, Solrize®) and one laboratory inoculum (Rhizophagus irregularis) were tested for mycorrhizal development and protection against B. graminis f. sp. tritici of two moderately susceptible and resistant wheat cultivars at P/5. Mycorrhizal levels were the highest with F. mosseae (38 %), followed by R. irregularis (19 %) and Solrize® (SZE, 8 %). On the other hand, the highest protection level against B. graminis f. sp. tritici was obtained with F. mosseae (74 %), followed by SZE (58 %) and R. irregularis (34 %), suggesting that inoculum type rather than mycorrhizal levels determines the protection level of wheat against B. graminis f. sp. tritici. The mycorrhizal protective effect was associated with a reduction in the number of conidia with haustorium and with an accumulation of polyphenolic compounds at B. graminis f. sp. tritici infection sites. Both the moderately susceptible and the most resistant wheat cultivar were protected against B. graminis f. sp. tritici infection by F. mosseae inoculation at P/5, although the underlying mechanisms appear rather different between the two cultivars. This study emphasizes the importance of taking into account the considered

LA INOCULACIÓN CON Glomus fasciculatum EN EL CRECIMIENTO DE CUATRO ESPECIES FORESTALES EN VIVERO Y CAMPO

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William Hernández

2009-01-01

Full Text Available La presente investigación se realizó para conocer la respuesta de 4 especies forestales a la aplicación del Glomus fasciculatum en vivero y campo. En la fase de vivero se evalúo diámetro basal, altura total, peso seco del follaje y radicular, absorción de nutrimentos en el follaje y el sistema radicular. En campo se cuantificó altura total, diámetro, y absorción de nutrimentos en el follaje. Los resultados mostraron que en vivero los mayores incrementos promedio, en los tratamientos inoculados, los registró el ronrón (Astronium graveolens, la teca (Tectona grandis y el amarillón (Terminalia amazonia, con 48,9, 35,2 y 30,6%, respectivamente; mientras que en melina (Gmelina arborea el incremento fue de 16,9%. El mayor incremento se registró en el peso seco del follaje y en el radicular con 30,8 y 63%, respectivamente. En la absorción de nutrimentos el ronrón mostró diferencias en Mg, Cu, Zn, Mn y Fe, tanto en el follaje como en el sistema radicular; sin embargo, melina fue la especie que registró las concentraciones de nutrimentos superiores, aunque no significativas; las demás especies no registraron diferencias significativas. En el campo, en las plantas inoculadas, solamente melina reflejó diferencias significativas en diámetro y altura total, con un incremento de 37,9 y 31,7%, respectivamente. La absorción de nutrimentos de melina, amarillón y ronrón fue en promedio 32,2, 19,8 y 6,6%, respectivamente, con una mayor absorción en Ca, Mn, K y Fe. La mortalidad en vivero fue nula, mientras que en el campo, varió de acuerdo con la especie y el tratamiento. El aumento en el crecimiento de las 4 especies fue la tendencia común, a excepción de teca, que en el campo no mostró resultados positivos.

Glomus caroticus, environment, time parameters of cardiac and pathogenic mechanisms of formation of somatogenic depression and mixed encephalopathies on the methodological grounds of non-invasive hemogram analyzer

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Anatoly N. Malykhin

2013-05-01

Full Text Available Aims The aim is to determine interaction of risk factors (volume of ingested food and exogenous alcohol and their effects on thermal regulation of a body due to the changed activity of biochemical reactions of neuromediator regulatory systems, related to the synthesis of endogenous alcohol. Materials and methods Based on study of neurological status, biochemical and instrumental methods of precordial mapping, urine specific gravity and thermometry of five biologically active points, 1200 males were examined for pathogenic mechanisms of endogenous alcohol synthesis and formation of time parameters of cardiac and clinical manifestation of somatogenic depression, metabolic syndrome and alcohol abuse with formation of encephalopathies. Results The amount of endogenous alcohol determines disorders in the bradykininacetylcholine and dopamine-noradrenalin systems and formation of clinical syndromes in the continuum of somatogeny-psychogeny (according to the international classification of diseases (ICD-10. Conclusion Changes in thermal regulation were accompanied with changes of functional mechanisms of Glomus Caroticus, affecting erythrocyte and its receptors, related to atomic oxygen and hydrogen in atmosphere, with formation of relevant pH values of arterial and venous blood, amount of endogenous alcohol.

Spore communities of arbuscular mycorrhizal fungi and mycorrhizal associations in different ecosystems, south Australia

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Z. I. Antoniolli

2002-09-01

Full Text Available Communities of arbuscular mycorrhizal fungi (AMF were surveyed in different South Australian ecosystems. The soil was wet-sieved for spore extraction, followed by the determination of presence and abundance of AMF species as well as the percentage of root colonization. Mycorrhizal associations were common and there was substantial fungal diversity in different ecosystems. Spores were most abundant in the permanent pasture system and less abundant under continuous wheat. The incidence of mycorrhizal associations in different plant species and the occurrence of Arum and Paris type colonization generally conformed with previous information. Spores of seventeen AMF were verified throughout seasonal changes in 1996 and 1997 in the permanent pasture and on four host species (Lolium perenne, Plantago lanceolata, Sorghum sp. and Trifolium subterraneum , set up with the same soils under greenhouse conditions. Glomus mosseae was the dominant spore type at all sampling times and in all trap cultures. Mycorrhizal diversity was significantly affected by different sampling times in trap cultures but not in field-collected soil. P. lanceolata, Sorghum sp. and T. subterraneum as hosts for trap cultures showed no differences in richness and diversity of AMF spores that developed in association with their roots. Abundance and diversity were lowest, however, in association with L. perenne , particularly in December 1996. Results show that the combination of spore identification from field-collected soil and trap cultures is essential to study population and diversity of AMF. The study provides baseline data for ongoing monitoring of mycorrhizal populations using conventional methods and material for the determination of the symbiotic effectiveness of AMF key members.

An invasive plant promotes its arbuscular mycorrhizal symbioses and competitiveness through its secondary metabolites: indirect evidence from activated carbon.

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Yuan, Yongge; Tang, Jianjun; Leng, Dong; Hu, Shuijin; Yong, Jean W H; Chen, Xin

2014-01-01

Secondary metabolites released by invasive plants can increase their competitive ability by affecting native plants, herbivores, and pathogens at the invaded land. Whether these secondary metabolites affect the invasive plant itself, directly or indirectly through microorganisms, however, has not been well documented. Here we tested whether activated carbon (AC), a well-known absorbent for secondary metabolites, affect arbuscular mycorrhizal (AM) symbioses and competitive ability in an invasive plant. We conducted three experiments (experiments 1-3) with the invasive forb Solidago canadensis and the native Kummerowia striata. Experiment 1 determined whether AC altered soil properties, levels of the main secondary metabolites in the soil, plant growth, and AMF communities associated with S. canadensis and K. striata. Experiment 2 determined whether AC affected colonization of S. canadensis by five AMF, which were added to sterilized soil. Experiment 3 determined the competitive ability of S. canadensis in the presence and absence of AMF and AC. In experiment 1, AC greatly decreased the concentrations of the main secondary metabolites in soil, and the changes in concentrations were closely related with the changes of AMF in S. canadensis roots. In experiment 2, AC inhibited the AMF Glomus versiforme and G. geosporum but promoted G. mosseae and G. diaphanum in the soil and also in S. canadensis roots. In experiment 3, AC reduced S. canadensis competitive ability in the presence but not in the absence of AMF. Our results provided indirect evidence that the secondary metabolites (which can be absorbed by AC) of the invasive plant S. canadensis may promote S. canadensis competitiveness by enhancing its own AMF symbionts.

Laser microdissection reveals that transcripts for five plant and one fungal phosphate transporter genes are contemporaneously present in arbusculated cells.

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Balestrini, Raffaella; Gómez-Ariza, Jorge; Lanfranco, Luisa; Bonfante, Paola

2007-09-01

The establishment of a symbiotic interaction between plant roots and arbuscular mycorrhizal (AM) fungi requires both partners to undergo significant morphological and physiological modifications which eventually lead to reciprocal beneficial effects. Extensive changes in gene expression profiles recently have been described in transcriptomic studies that have analyzed the whole mycorrhizal root. However, because root colonization by AM fungi involves different cell types, a cell-specific gene expression pattern is likely to occur. We have applied the laser microdissection (LMD) technology to investigate expression profiles of both plant and fungal genes in Lycopersicon esculentum roots colonized by Glomus mosseae. A protocol to harvest arbuscule-containing cells from paraffin sections of mycorrhizal roots has been developed using a Leica AS LMD system. RNA of satisfactory quantity and quality has been extracted for molecular analysis. Transcripts for plant phosphate transporters (LePTs), selected as molecular markers for a functional symbiosis, have been detected by reverse-transcriptase polymerase chain reaction assays and associated to distinct cell types, leading to novel insights into the distribution of LePT mRNAs. In fact, the transcripts of the five phosphate transporters (PTs) have been detected contemporaneously in the same arbusculated cell population, unlike from the neighboring noncolonized cells. In addition, fungal H(+)ATPase (GmHA5) and phosphate transporter (GmosPT) mRNAs were found exclusively in arbusculated cells. The discovery that five plant and one fungal PT genes are consistently expressed inside the arbusculated cells provides a new scenario for plant-fungus nutrient exchanges.

Avaliação da interação micorrízica em cultivares de oliveira (Olea europea L.

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Vanessa Cristina Silva Vieira

2011-12-01

Full Text Available A maioria dos estudos com oliveira no Brasil e no mundo tem sido direcionada à produção e ao manejo. Apesar da importância para o crescimento vegetal e resistência a estresses diversos, não há estudos sobre a ocorrência de associação micorrízica em oliveira, no Brasil. O objetivo do presente trabalho foi avaliar a interação micorrízica em cultivares de oliveira na Fazenda Experimental de Maria da Fé - MG (FEMF - EPAMIG, a qual serve como ponto de partida na produção de inoculantes comerciais de fungos micorrízicos arbusculares para a cultura. Amostras de solo e de raízes de sete cultivares de oliveira foram coletadas para determinação do comprimento de micélio extrarradicular ativo e total e avaliação da percentagem e intensidade de colonização micorrízica, bem como da densidade e diversidade de esporos. Nas rizosferas das cultivares de oliveira, foram isoladas nove espécies de fungos micorrízicos: Acaulospora denticulata, Acaulospora scrobiculata, Acaulospora sp1, Acaulospora sp2, Entrophospora sp1, Gigaspora sp1, Glomus mosseae, Scutellospora pellucida e Scutellospora sp1. Os resultados comprovaram o micotrofismo da espécie. No entanto, não houve efeito das cultivares na distribuição dos propágulos de FMAs, os quais estiveram homogeneamente distribuídos nas diferentes rizosferas.

Influence of Glomus etunicatum and Glomus intraradices fungi ...

African Journals Online (AJOL)

aghomotsegin

The objectives of this study were to determine the effects of micronutrient deficiency on root colonization by arbuscular mycorrhizal fungi (AMF), and to assess the role of AMF on growth of sorghum and tomato plants in perlite bed culture. In a pot culture experiment with sterile perlite, sorghum (Sorghum bicolor L.) and ...

Combined Inoculation with Multiple Arbuscular Mycorrhizal Fungi Improves Growth, Nutrient Uptake and Photosynthesis in Cucumber Seedlings

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Shuangchen Chen

2017-12-01

Full Text Available Mycorrhizal inoculation stimulates growth, photosynthesis and nutrient uptake in a wide range of host plants. However, the ultimate effects of arbuscular mycorrhyzal (AM symbiosis vary with the plants and fungal species involved in the association. Therefore, identification of the appropriate combinations of AM fungi (AMF that interact synergistically to improve their benefits is of high significance. Here, three AM fungal compositions namely VT (Claroideoglomus sp., Funneliformis sp., Diversispora sp., Glomus sp., and Rhizophagus sp. and BF (Glomus intraradices, G. microageregatum BEG and G. Claroideum BEG 210, and Funneliformis mosseae (Fm were investigated with respect to the growth, gas exchange parameters, enzymes activities in Calvin cycles and related gene expression in cucumber seedlings. The results showed that VT, BF and Fm could successfully colonize cucumber root to a different degree with the colonization rates 82.38, 74.65, and 70.32% at 46 days post inoculation, respectively. The plant height, stem diameter, dry weight, root to shoot ratio of cucumber seedlings inoculated with AMF increased significantly compared with the non-inoculated control. Moreover, AMF colonization greatly increased the root activity, chlorophyll content, net photosynthetic rate, light saturated rate of the CO2 assimilation (Asat, maximum carboxylation rate (Vcmax and maximum ribulose-1,5-bis-phosphate (RuBP regeneration rate (Jmax, which were increased by 52.81, 30.75, 58.76, 47.00, 69.15, and 65.53% when inoculated with VT, respectively. The activities of some key enzymes such RuBP carboxylase/oxygenase (RuBisCO, D-fructose-1,6-bisphosphatase (FBPase, D-fructose-6-phosphatase (F6P and ribulose-5-phosphate kinase (Ru5PK, and related gene expression involved in the Calvin cycle including RCA, FBPase, FBPA, SBPase, rbcS and rbcL were upregulated by AMF colonization. AMF inoculation also improved macro- and micro nutrient contents such as N, P, K, S, Ca, Cu

The interactive effect of phosphorus and nitrogen on "in vitro" spore germination of Glomus etunicatum Becker & Gerdemann, root growth and mycorrhizal colonization

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Bressan Wellington

2001-01-01

Full Text Available The effects of P and N amendment and its interactions on spore germination, root growth and colonized root length by Glomus etunicatum Becker & Gerdemann (INVAM S329 was studied "in vitro" in RiT - DNA transformed roots of Anthylis vulneraria sub sp. Sampaiana (Kidney vetch. Three N media concentrations (5, 10 and 50 mg/l at P constant level (2 mg/l and three P media concentrations (2, 10 and 20 mg/l at N constant level (5 mg/l were utilized as a treatment. Bécard & Fortin medium was used as a basal medium for root growth and colonized root length, and water/agar (0.8% media was the control for spore germination. Spore germination of G. etunicatum at low P level was reduced by N addition in relation to the control media, and at low N level addition of P stimulated spore germination. Total root length was stimulated by N addtion at low P level, but no significant difference (p£0.05 was observed between 10 and 50 mg/l of N. P addition at low N level media also stimulated total root growth, and a significant difference (p£0.05 was observed among P concentrations. Colonized root length by G. etunicatum increased significantly (p£0.05 with P additions at low N levels. Under low P level no significant differences was found between 10 and 50 mg/l of N. These results demonstrate that the interaction between P and N affect differently spore germination, root growth and colonized root lenght.

Fungos micorrízicos arbusculares em solos de área poluída com metais pesados

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O. Klauberg-Filho

2002-03-01

Full Text Available Os fungos micorrízicos arbusculares (FMAs ocorrem de forma generalizada e formam importante simbiose com a maioria das plantas, mesmo em solos poluídos com metais pesados. Neste estudo, avaliaram-se a ocorrência e a diversidade dos FMAs em quatro locais com gramíneas em uma área de solo contaminado com metais pesados pela extração e industrialização do Zn. Verificou-se a ocorrência generalizada dos FMAs nos locais estudados, sendo esta influenciada pelas concentrações de metais no solo. Encontrou-se um total de 21 espécies, sendo: sete pertencentes ao gênero Acaulospora, seis de Scutellospora, cinco de Glomus, duas de Gigaspora e uma de Entrophospora,Glomus occultum, Acaulospora morrowiae, Acaulospora mellea, Glomus intraradices, Glomus clarum e Scutellospora pellucida foram as de maior ocorrência. A densidade de esporos, a riqueza de espécies e o aumento da dominância relacionaram-se inversamente com as concentrações de metais no solo. Acaulospora mellea, Glomus clarum e Glomus occultum dominaram as populações de esporos no solo. Concluiu-se que os metais pesados exerceram efeito diferenciado sobre os FMAs, dependendo do grau de poluição.

Differential effects of Pseudomonas mendocina and Glomus intraradices on lettuce plants physiological response and aquaporin PIP2 gene expression under elevated atmospheric CO2 and drought.

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Alguacil, Maria Del Mar; Kohler, Josef; Caravaca, Fuensanta; Roldán, Antonio

2009-11-01

Arbuscular mycorrhizal (AM) symbiosis and plant-growth-promoting rhizobacterium (PGPR) can alleviate the effects of water stress in plants, but it is unknown whether these benefits can be maintained at elevated CO2. Therefore, we carried out a study where seedlings of Lactuca sativa were inoculated with the AM fungus (AMF) Glomus intraradices N.C. Schenk & G.S. Sm. or the PGPR Pseudomonas mendocina Palleroni and subjected to two levels of watering and two levels of atmospheric CO2 to ascertain their effects on plant physiological parameters and gene expression of one PIP aquaporin in roots. The inoculation with PGPR produced the greatest growth in lettuce plants under all assayed treatments as well as the highest foliar potassium concentration and leaf relative water content under elevated [CO2] and drought. However, under such conditions, the PIP2 gene expression remained almost unchanged. G. intraradices increased significantly the AMF colonization, foliar phosphorus concentration and leaf relative water content in plants grown under drought and elevated [CO2]. Under drought and elevated [CO2], the plants inoculated with G. intraradices showed enhanced expression of the PIP2 gene as compared to P. mendocina or control plants. Our results suggest that both microbial inoculation treatments could help to alleviate drought at elevated [CO2]. However, the PIP2 gene expression was increased only by the AMF but not by the PGPR under these conditions.

Improved Growth And Colchicine Concentration In Gloriosa Superba ...

African Journals Online (AJOL)

AM), fungi, Glomus mossae, Glomus fasciculatum, Gigaspora margarita and Gigaspora gilmorei either alone or supplemented with P-fertilizer, on colchicine concentration in Gloriosa superba were studied. The concentration of colchicine was ...

Fungos micorrízicos arbusculares (Glomales, Zygomycota na Ilha dos Eucaliptos, Represa do Guarapiranga, São Paulo, SP Arbuscular mycorrhizal fungi (Glomales, Zygomycota from "Ilha dos Eucaliptos", Guarapiranga Reservoir, São Paulo, SP, Brazil

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Simone de Paula Gomes

1998-01-01

Full Text Available Com o objetivo de se conhecer a micota de fungos micorrízicos arbusculares (FMA, Glomales, Zygomycota, coletou-se amostras de solo rizosférico de plantas instaladas em três áreas (plantio de eucaliptos, mata e transição entre ambas em três épocas (março/1996, época chuvosa e final de verão; junho/1996, época de inverno; janeiro/1997, início das chuvas e do verão na Ilha dos Eucaliptos (cerca de 323.500m², na Represa do Guarapiranga, São Paulo, SP. O solo foi processado para a separação dos esporos de FMA segundo a técnica do peneiramento e decantação em via úmida, seguindo-se centrifugação em solução de sacarose 50% (V:V. Os esporos isolados foram preparados em lâminas permanentes com resina PVL. Foram constatados 21 táxons de FMA: Acaulospora excávala Ingleby, Walker & Mason, Acaulospora foveata Trappe & Janos, Acaulospora longula Spain & Schenck, Acaulospora mellea Spain & Schenck, Acaulospora morrowiae Spain & Schenck, Acaulospora spinosa Walker & Trappe, Acaulospora sp. 1, Acaulospora sp. 2, Acaulospora sp. 3, Acaulospora sp. 4, Entrophospora colombiana Spain & Schenck, Gigaspora gigantea Nicol. & Gerd., Gigaspora ramisporopfwra Spain, Sieverding & Schenck, Glomus aggregatum (Schenck & Smith Koske, Glomus etunicatum Becker & Gerd., Glomus geosporum (Nicol. & Gerd. Walker, Glomus invennayum Hall, Glomus macrocarpum Tul. & Tui., Glomus multisubstensum Mukerjii, Bhattacharjee & Tewari, Scutellospora aff. biornata Spain, Sieverding & Toro e Scutellospora erythropa Koske & Walker. A aplicação do índice de similaridade de Sõrensen entre populações de FMA nas diferentes áreas e as épocas de coletas mostrou valores de 64 a 90%, sugerindo não haver seleção dos FMA mediada por esses fatores.With the aim of verifying the occurence of arbuscular mycorrhizal fungi AMF, Glomales, Zygomycota, rhizosphere soil samples were collected in three areas (eucaliptus reforestation, forest and intersection and on three

Crescimento e composição mineral da menta em resposta à inoculação com fungos micorrízicos arbusculares e adubação fosfatada Growth and mineral composition of mint in response to arbuscular mycorrhizal fungi inoculation and phosphorus fertilization

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Marta Simone M Freitas

2006-03-01

Full Text Available Foram avaliados os efeitos de fungos micorrízicos arbusculares (FMA no crescimento e composição mineral de Mentha arvensis L., cultivada com diferentes doses de fósforo. O experimento foi realizado em casa de vegetação e o delineamento estatístico utilizado foi de blocos ao acaso, num fatorial 5x4, sendo cinco tratamentos microbiológicos (controle, Glomus clarum, Glomus etunicatum, Gigaspora margarita e Acaulospora scrobiculata e quatro doses de P (0; 50; 100 e 200 mg kg-1, com quatro repetições. As plantas foram colhidas na fase de floração, aos 65 dias após o plantio. Verificou-se que, na ausência de P, os fungos Glomus clarum e Gigaspora margarita apresentaram maiores percentagens de colonização micorrízica nas raízes e proporcionaram aumentos de 330 e 334% na matéria seca foliar, de 143 e 123% no conteúdo de N, de 224 e 124% no conteúdo de P e de 139 e 142% no conteúdo de K, respectivamente. Os FMA não influenciaram os conteúdos de Ca, Mg, S, Fe e Zn na matéria seca foliar. As doses de P entre 122 e 165 mg kg-1 de solo proporcionaram as maiores produções de matéria seca. Nessas doses, o conteúdo de Mn foi menor quando as plantas foram inoculadas com Glomus clarum, Gigaspora margarita e Glomus etunicatum. A dependência micorrízica da menta variou de acordo com a espécie de fungo e a dose de P utilizada, sendo maior com os fungos Glomus clarum e Gigaspora margarita, na ausência de P.The effects of arbuscular mycorrhizal fungi (AMF were evaluated on the growth and mineral composition of Mentha arvensis L., grown under different phosphorus levels. The experiment was carried out in a greenhouse, in a factorial scheme 5x4, with five microbiological treatments (control without AMF, Glomus clarum, Glomus etunicatum, Gigaspora margarita and Acaulospora scrobiculata and four P levels (0; 50; 100 and 200 mg kg-1. A randomized block design was used, with four replications. The plants were harvested at flowering, 65 days

Desempenho de fungos micorrízicos arbusculares na produção de mudas de maracujazeiro-amarelo, em diferentes substratos Arbuscular mycorrhizal fungi performance to produce mycorrhizal passionflower seedlings under different substrates

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Adriana Parada Dias da Silveira

2003-01-01

Full Text Available O trabalho teve por objetivo selecionar fungos micorrízicos arbusculares (FMAs eficientes na promoção do crescimento de mudas de maracujazeiro-amarelo, em substrato esterilizado, com diferentes níveis de fertilidade, em função da adição ou não de matéria orgânica. Foram realizados três experimentos, em casa de vegetação. No primeiro, empregou-se como substrato uma mistura de 2:1:1 de areia, solo (Latossolo Vermelho Eutroférrico e esterco de curral; no segundo, uma mistura de 1:1 de solo e areia e no terceiro, uma mistura de 9:1 de solo e esterco de curral. Os FMAs empregados foram: Acaulospora sp.(IAC-13, Gigaspora margarita, Glomus sp (IAC-27, Acaulospora morrowae, Acaulospora sp. (IAC-44, Acaulospora scrobiculata, Scutellospora heterogama, Glomus clarum,Glomus sp. (IAC-28, Entrophospora colombiana, Glomus etunicatum e Glomus macrocarpum. No terceiro experimento, empregaram-se G. clarum, Glomus sp. (IAC-28, G. margarita, G. etunicatum e G. macrocarpum (IAC-50, uma mistura dessas espécies e populações de fungos nativos, oriundas de solo de uma cultura de maracujá estabelecida no campo e multiplicadas em Brachiaria decumbens, maracujazeiro e amendoinzeiro. Os efeitos positivos da micorrização foram maiores no substrato sem adição de matéria orgânica (esterco de curral, não superando, entretanto, o efeito da sua adição. G. clarum, G. etunicatum e G. margarita promoveram aumento significativo na produção de matéria seca. No substrato com adição de 25% de matéria orgânica, os fungos Acaulospora sp. (IAC- 44 e A. morrowae foram eficientes na promoção do desenvolvimento das mudas, com desempenho comparável ao Glomus sp. (IAC- 28 no substrato com adição de 10% de esterco de curral. G. clarum mostrou efeito parasítico, diminuindo o crescimento das plantas no substrato com 25% de matéria orgânica.The purpose of this study was to select effective arbuscular mycorrhizal fungi (AMF on the production of yellow

An invasive plant promotes its arbuscular mycorrhizal symbioses and competitiveness through its secondary metabolites: indirect evidence from activated carbon.

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Yongge Yuan

Full Text Available Secondary metabolites released by invasive plants can increase their competitive ability by affecting native plants, herbivores, and pathogens at the invaded land. Whether these secondary metabolites affect the invasive plant itself, directly or indirectly through microorganisms, however, has not been well documented. Here we tested whether activated carbon (AC, a well-known absorbent for secondary metabolites, affect arbuscular mycorrhizal (AM symbioses and competitive ability in an invasive plant. We conducted three experiments (experiments 1-3 with the invasive forb Solidago canadensis and the native Kummerowia striata. Experiment 1 determined whether AC altered soil properties, levels of the main secondary metabolites in the soil, plant growth, and AMF communities associated with S. canadensis and K. striata. Experiment 2 determined whether AC affected colonization of S. canadensis by five AMF, which were added to sterilized soil. Experiment 3 determined the competitive ability of S. canadensis in the presence and absence of AMF and AC. In experiment 1, AC greatly decreased the concentrations of the main secondary metabolites in soil, and the changes in concentrations were closely related with the changes of AMF in S. canadensis roots. In experiment 2, AC inhibited the AMF Glomus versiforme and G. geosporum but promoted G. mosseae and G. diaphanum in the soil and also in S. canadensis roots. In experiment 3, AC reduced S. canadensis competitive ability in the presence but not in the absence of AMF. Our results provided indirect evidence that the secondary metabolites (which can be absorbed by AC of the invasive plant S. canadensis may promote S. canadensis competitiveness by enhancing its own AMF symbionts.

Efecto de la inoculación con Glomus intraradices y de la fertilización nitrogenada en el crecimiento de plantas de fresa

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C.S. Salgado-Barreiro

2012-01-01

Full Text Available El objetivo de este trabajo fue evaluar el efecto de la inoculación del HMA Glomus intraradices en el crecimiento de las plantas de fresa variedad Camino Real, fertirrigadas con 0, 1, 3 y 10 mM de N en forma de NH4 + ó NO3 -. Se realizó un experimento en condiciones de invernadero, en el que se evaluó el porcentaje de colonización, el peso seco de las raíces (PSR y de la parte aérea (PSPA, a los 33 y 48 dias después del establecimiento (dde. El porcentaje de colonización se redujo conforme al incremento de la concentración de NH4 + ó NO3 - en la solución de riego; a los 33 dde, la inoculación de G. intraradices incrementó el PSR y el PSPA en las plantas fertilizadas con NH4 +; y a los 48 dde se observó el mismo efecto en las plantas que recibieron NO3 -. En ambos casos, los valores más altos de biomasa aérea y radical se registraron en las plantas fertirrigadas con bajas concentraciones de N. Estos resultados indican que la inoculación con G. intraradices tiene el potencial de reducir la aplicación de fertilizantes nitrogenados en el cultivo de fresa. Además, el exceso de N inhibe la colonización de HMA sin incrementar el crecimiento de la planta. Así mismo, el efecto de la inoculación de G. intraradices, forma y dosis de fertilizante nitrogenado depende de la fase de crecimiento de la planta.

Evaluating the growth parameters of soybean in response to plant growth promoting fungi under Mazandaran climate conditions

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mohammad yazdani

2016-05-01

Full Text Available Abstract In low-input cropping systems, the natural roles of microorganisms in maintaining soil fertility may be more important than conventional system. In order to investigate the effects of plant growth promoting fungi on improvement of growth and development in soybean (cv: JK an experiment was conducted at the research farm of Sari Agricultural Sciences and Natural Resources University during the 2011-2012 growing seasons. Treatments were arranged in a factorial experiment based a completely randomized block design with three replications. The first factor was six levels of fungi: inoculation T. harzianum and AMF genus Glumus: G. mosseae, G. intraradices, and co-inoculation of T. harzianum + G. mosseae, T. harzianum + G. intraradices and non-inoculation (control. The second factor was three levels of phosphorus (0, 70 and 140 kg.ha-1 from superphosphate trip. Results showed that inoculation of T. harzianum and G. mosseae significantly had maximum chlorophyll content up to 17% and 16% at reduced phosphorus dosage (70 kg.ha-1 and conventional phosphorus dosage as compared to the control respectively. The greatest effect was recorded at reduced phosphorus dosage (70 kg.ha-1 and conventional phosphorus dosage significant increase in terms of chlorophyll content. In addition, the dry weights and chlorophyll content of soybean plants in reduced phosphorous dosage (70 kg.ha-1 and co-inoculated with T. harzianum + G. mosseae as well as conventional phosphorous dosage were significantly higher than the non-inoculated plants. In this experiment, at reduce phosphate fertilizer (P0%: 0 treatment, not affected of plant growth promoting fungi compared to control. But, reduced phosphorous dosage (70 kg.ha-1 was more affected.

Jugular and vagal paragangliomas: Systematic study of management with surgery and radiotherapy

NARCIS (Netherlands)

Suarez, C.; Rodrigo, J.P.; Bodeker, C.C.; Llorente, J.L.; Silver, C.E.; Jansen, J.C.; Takes, R.P.; Strojan, P.; Pellitteri, P.K.; Rinaldo, A.; Mendenhall, W.M.; Ferlito, A.

2013-01-01

BACKGROUND: The definitive treatment for head and neck paraganglioma (PG) is surgical excision. Unfortunately, surgery, particularly of vagal paraganglioma (VPG; "glomus vagale") and foramen jugulare ("glomus jugulare") tumors, may be complicated by injuries to the lower cranial nerves, a high price

Aspectos ecológicos de fungos micorrízicos vesículo-arbusculares da mata tropical úmida da Ilha do Cardoso, SP, Brasil Ecological aspects of mycorrhizal vesicular-arbuscular fungi of the tropical humid forest of Cardoso Island, SP, Brazil

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Sandra F. B Trufem

1990-12-01

Full Text Available No período de agosto/1984 a maio/1987, em nove ocasiões, foram coletadas 300 amostras de solo da rizosfera de 35 espécies de plantas nativas da mata tropical úmida do Parque Estadual da Ilha do Cardoso, SP, Brasil, para a investigação da ocorrência de fungos micorrízicos vesículo-arbusculares (MVA ea obtenção de dados sobre aspectos ecológicos desses microrganismos. Foram verificados 35 taxa de fungos MV A, sete dos quais espécies novas. Os esporos qué ocorreram em maior quantidade foram os de Acaulospora foveata Trappe & Janos, Acaulospora scrobiculata Trappe, Glomus etunicatum Becker & Gerd.. Glomus geosporum (Nicol. & Gerd. Walker, Glomus macrocarpum Tul. & Tul. e Glomus microcarpum Tul. & Tul. As plantas cujas rizosferas apresentaram maior número de esporos de fungos MV A foram as de Blechnum serrulatum L.C. Rich., Euterpe edulis Mart, Neomarica caerulia Sprague, Geonoma elegans Mart, e Piper aduncum L. A maior diversidade de espécies de fugnos MV A ocorreu nas rizosferas de Aphettandra sp., Geonoma elegans Mart e Leandra barbinervis Cogn. Verificouse que houve predominancia de espécies de fungos micorrízicos vesículo-arbusculares clamidospóricas sobre as azigospóricas, bem como que a quantidade de esporos em urna dada rizosfera está diretamente relacionada com a diversidade. Glomus monosporum Gerd. & Trappe e as espécies de Sclerocystis podem ser apontadas como características do ecossistema estudado, que apresentou a média de 50,04 esporos/ 100g de solo.From August/1984 to May/1987, 300 soil samples were collected from the rhizospheres of 35 species of native plants of Parque Estadual da Ilha do Cardoso, SP, Brazil, in a wet tropical forest, to investigate the occurrence and some ecological aspects of vesicular-arbuscular mycorrhizal (VAM fungi. Thirty five taxa of VA M fungi were reported, seven of them as new species. The most numerous VA M fungal spores belong to Acaulospora foveata Trappe & Janos, Acaulospora

Fungos micorrízicos nativos e Glomus clarun no rendimento de trevo vesiculoso cultivado em condições naturais e modificadas pela calagem e aplicação de fósforo Glomus clarun and native mycorrhizal fungi on yield of Trifolium spp. cultivated under natural and modified soil contitions with addition by phosphorus and liming

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Antonio Carlos dos Santos Pessoa

1997-03-01

Full Text Available Em experimento desenvolvido na casa de vegetação na UFSM-RS, avaliou-se o efeito da introdução de fungos micorrizicos arbusculares (fMA Glomus clarum e nativos no rendimento de massa seca (MS e absorção de P pelo trevo vesiculoso (Trifolium spp. e verificou-se a compatibilidade entre a espécie introduzida e os fMA nativos ocorrentes no solo estudado. Os tratamentos/oram constituídos defatorial 4x2x2 com quatro níveis de fMA: G. clarum, fungos nativos, mistura de ambas as populações e controle sem inoculação de fMA: com dois valores de pH: 4,4 e 5,4 e com dois níveis de fósforo disponível (Mehlich l: 6 e ISmg/kg de solo. A introdução de G. clarum isoladamente ou em conjunto com fMA nativos, na condição de pH 4,4, e em baixa disponibilidade de P, aumentou o rendimento de MS e absorção de P. Em disponibilidade intermediária de P (l5mg/kg de solo e pH 5,4 não ocorreu diferença entre os tratamentos inoculados com fMA, mas destes ocorreu diferença para o tratamento sem inoculação, evidenciando a dependência do trevo pela micorrizaçâo. Tratamentos inoculados com G. clarum apresentaram maiores rendimentos de MS, absorção de P, colonização micorrizica e esporulação, mostrando que a introdução dessa espécie pode ser viável quando espécies nativas não são eficientes para a cultura ou tornam-se ineficientes quando a fertilidade do solo é modificada por aplicação de P e/ou calagem.The experiment v/as conducted under greenhouse condition at the University of Santa Maria, RS, Brazil. The objectives were to evaluate the introduction of arbuscular mycorrhizalfúngi (AMF Glomus clarum and natives fungi on the phosphorus uptake and dry matter (DM production from Trifolium spp. and Io verify lhe compatibilily between introduced specie and lhe nativo AMF occurence in lhe studied soil. The treatments was constituled of 4x2x2 factorial withfour AMF leveis: G. clarum, AMf native, mixture of both populations of AMF

Growth and Yield Response of Watermelon to in-row Plant Spacings and Mycorrhiza Respuesta del Crecimiento Vegetativo y Producción de Sandía a Diferentes Distancias entre Plantas y a Micorrizas

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Dean Ban

2011-12-01

Full Text Available Worldwide, a significant increase in watermelon (Citrullus lanatus [Thunb.] Matsum. & Nakai growing areas has been registered in the last few years. In-row plant spacing has a significant effect on the growth and yield of watermelon, and can enhance competition for water and nutrients. The aim of this study was to investigate the effects of in-row plant spacing (1.0, 1.5, 2.0 and 2.5 m and arbuscular mycorrhiza (AM fungi Glomus mosseae inoculations on watermelon growth and yield under field conditions during 2003, 2004, and 2005 year. In 2003, the main vine length, number of leaves, and number of lateral branches were increased quadratically as the in-row plant spacing increased from 1.0 to 2.5. With an increase in the in-row plant spacing the early yield of watermelon decreased in 2004, while the fruit number decreased in 2003 and 2004. The total yield and fruit number decreased with an increase in the in-row plant spacing in all 3 yr; however, the fruit mass increased at wider plant spacings in 2003. Mycorrhizal inoculation increased the main vine length and the number of lateral branches in 2003. Compared to non-mycorrhizal plants, mycorrhizal plants presented higher early yield in 2005 and a higher early fruit number in 2003 and 2005. Mycorrhizal inoculation increased total yield in 2005; however, the fruit weight was not affected by mycorrhizal inoculation during early or total harvest. In this study, an in-row plant spacing of 1.0 m provided the best early and total yield while maintaining high fruit weight. The growth and yield enhancement of watermelon due to mycorrhizal colonization was not consistent; therefore, mycorrhizal inoculation could not be recommended as a standard production practice.En los últimos años se ha registrado un significativo aumento en las áreas cultivadas con sandía (Citrullus lanatus [Thunb.] Matsum. & Nakai a nivel mundial. La distancia entre plantas en la hilera tiene un efecto significativo en su

The Effects of Biological Fertilizers, Chemical Fertilizers and Manure Application on Some Qualitative Characteristics of Vicia villosa Roth Forage under Greenhouse Condition

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R Kamaei

2017-03-01

Full Text Available Introduction Fertilizer management plays an important role in successful crop production. The biological fertilizers have been suggested not only to elimination or significant reduction of chemical fertilizer dependency but also increase of soil fertility and improvement of crop yield and quality. Materials and Methods This experiment was conducted in a completely randomized design with three replications at the Research Greenhouse of Ferdowsi University of Mashhad. The experimental treatments included 1- mycorrhizae arbuscular (Glomus mosseae, 2- mycorrhizae arbuscular (Glomus mosseae + vermicompost (M+V, 3- mycorrhizae + nitroxein (included bacteria Azospirillum sp. and Azotobacter sp. (M+N, 4- mycorrhizae arbuscular + Rhizobium (R. legominuzarum (M+R, 5-mycorrhizae arbuscular + NPK Chemical fertilizer (40-40-20 (M+NPK and 6- Control (without fertilizer, C. In bio-fertilizer treatments, seeds were inoculated by mycorrhizae and Rhizobium immediately before planting, according the standard conditions and company recommendations. Chemical fertilizer and vermicompost were applied directly into the soil. The first irrigation was done immediately after planting and an additional irrigation was also done 4 days after planting to improve the seedling emergence. Subsequent irrigations were conducted at 10-days interval. Forage samples were collected at stage of 10% open bud. The samples were oven-dried in 70°C for 48 h and then weighed before being ground to pass through a 1-mm sieve. Both chemical analysis and in vitro digestibility assessments were performed in triplicate. Crud protein (CP, Ash, neutral detergent fiber (NDF and acid detergent fiber (ADF content of forages were measured by standard methods. An in vitro gas production method was conducted to determine the dry matter (DM and organic matter (OM digestibility. All data were subjected to ANOVA using the GLM procedure of SAS (SAS 9.1 and means were compared by using LSD-test at 5

Occurrence of arbuscular mycorrhizal fungi on King George Island, South Shetland Islands, Antarctica.

Science.gov (United States)

Barbosa, Marisângela V; Pereira, Elismara A; Cury, Juliano C; Carneiro, Marco A C

2017-01-01

Arbuscular mycorrhizal fungi make up an important ecological niche in ecosystems, and knowledge of their diversity in extreme environments is still incipient. The objective of this work was to evaluate the density and diversity of arbuscular mycorrhizal fungi in the soil of King George Island in the South Shetland Islands archipelago, Antarctica. For that, soil and roots of Deschampsia antarctica were collected at the brazilian research station in Antarctica. The spore density, species diversity and mycorrhizal colonization in the roots were evaluated. There was a low density of spores (27.4 ± 17.7) and root mycorrhizal colonization (6 ± 5.1%), which did not present statistical difference. Four species of arbuscular mycorrhizal fungi were identified, distributed in two genera: three species of the genus Glomus (Glomus sp1, Glomus sp2 and Glomus sp3) and one of the genus Acaulospora, which was identified at species level (Acaulospora mellea). Greater soil diversity was verified with pH 5.9 and phosphorus concentration of 111 mg dm-3, occurring two species of genus Glomus and A. mellea. Based on literature data, this may be the first record of this species of Acaulospora mellea in Antarctic soils, colonizing D. antarctica plants.

Arbuscular Mycorrhizal Fungus Species Dependency Governs Better Plant Physiological Characteristics and Leaf Quality of Mulberry (Morus alba L.) Seedlings.

Science.gov (United States)

Shi, Song-Mei; Chen, Ke; Gao, Yuan; Liu, Bei; Yang, Xiao-Hong; Huang, Xian-Zhi; Liu, Gui-Xi; Zhu, Li-Quan; He, Xin-Hua

2016-01-01

Understanding the synergic interactions between arbuscular mycorrhizal fungi (AMF) and its host mulberry (Morus alba L.), an important perennial multipurpose plant, has theoretical and practical significance in mulberry plantation, silkworm cultivation, and relevant textile industry. In a greenhouse study, we compared functional distinctions of three genetically different AMF species (Acaulospora scrobiculata, Funneliformis mosseae, and Rhizophagus intraradices) on physiological and growth characteristics as well as leaf quality of 6-month-old mulberry seedlings. Results showed that mulberry was AMF-species dependent, and AMF colonization significantly increased shoot height and taproot length, stem base and taproot diameter, leaf and fibrous root numbers, and shoot and root biomass production. Meanwhile, leaf chlorophyll a or b and carotenoid concentrations, net photosynthetic rate, transpiration rate and stomatal conductance were generally significantly greater, while intercellular CO2 concentration was significantly lower in AMF-inoculated seedlings than in non-AMF-inoculated counterparts. These trends were also generally true for leaf moisture, total nitrogen, all essential amino acids, histidine, proline, soluble protein, sugar, and fatty acid as they were significantly increased under mycorrhization. Among these three tested AMFs, significantly greater effects of AMF on above-mentioned mulberry physiological and growth characteristics ranked as F. mosseae > A. scrobiculata > R. intraradices, whilst on mulberry leaf quality (e.g., nutraceutical values) for better silkworm growth as F. mosseae ≈A. scrobiculata > R. intraradices. In conclusion, our results showed that greater mulberry biomass production, and nutritional quality varied with AMF species or was AMF-species dependent. Such improvements were mainly attributed to AMF-induced positive alterations of mulberry leaf photosynthetic pigments, net photosynthetic rate, transpiration rate, and N

EFECTO DE LA INOCULACIÓN DE azotobacter chroococcum Y glomus intraradices EN EL CRECIMIENTO Y NUTRICIÓN DE PLÁNTULAS DE PAPAYA EN FASE DE VIVERO

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Maricela Constantino

2011-01-01

Full Text Available En el presente estudio se evaluó la etapa y el número de aplicaciones de los biofertilizantes (Azotobacter chroococcum y Glomus intraradices, sobre el crecimiento, biomasa y nutrición de papaya en fase de vivero. También se estudió el efecto de la materia orgánica y su interacción con los biofertilizantes aplicados. Se realizaron 2 experimentos; en el primero se aplicaron 2 inoculaciones, en semillas y después en plántulas, 30 días después de la emergencia. En el segundo se aplicó una inoculación simple en plántulas, 30 días después de la emergencia. Estos experimentos se realizaron utilizando un diseño factorial 5x4 (5 tipos de sustratos x 4 tipos de biofertilizantes. Todos los tratamientos fueron aplicados como inoculantes simples o combinados (A. chroococcum y G. intraradices para un total de 20 tratamientos, con un diseño completamente al azar. La doble inoculación (semilla y plántula promovió un mayor crecimiento y biomasa en el cultivo, en comparación con la inoculación simple (solo en plántulas, cuando se adicionó una dosis intermedia de materia orgánica (25 a 35% y se aplicó G. intraradices como simple inoculante. Sin embargo, la inoculación simple o combinada no modificó el contenido de nutrientes en las plántulas de papaya.

Mechanical soil disturbance as a determinant of arbuscular mycorrhizal fungal communities in semi-natural grassland

DEFF Research Database (Denmark)

Schnoor, Tim Krone; Lekberg, Ylva; Rosendahl, Søren

2011-01-01

an ongoing grassland restoration experiment that contained replicated plowed and control plots. The AM fungal community in roots was determined using nested PCR and LSU rDNA primers. We identified 38 phylotypes within the Glomeromycota, of which 29 belonged to Glomus A, six to Glomus B, and three...

ARBUSCULAR MYCORRHIZAL FUNGI INCREASED EARLY GROWTH OF GAHARU WOOD OF Aquilaria malaccencsis and A. crasna UNDER GREENHOUSE CONDITIONS

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Maman Turjaman

2006-07-01

Full Text Available Gaharu wood stand has an important source of profits to the forest community in South and Southeast Asia tropical forest countries, but Aquilaria species have reduced in number and turn out to be endangered due to overexploitation.   Today,   the planting stocks of   Aquilaria species are not sufficient to sustain the yield of gaharu wood and promote forest conservation.  The objective of this study was to determine   the effect of   five arbuscular mycorrhizal (AM fungi: Entrophospora sp., Gigaspora decipiens, Glomus clarum, Glomus sp. ZEA, and Glomus sp. ACA, on the early growth of  Aquilaria malaccensis and A. crasna under greenhouse conditions. The seedlings of  Aquilaria spp. were inoculated with Entrophospora sp., Gi. decipiens, Glomus clarum, Glomus sp. ZEA, Glomus sp. ACA and uninoculated (control under greenhouse conditions. Then, percentage AM colonization, plant growth, survival rate and nitrogen (N and phosphorus (P content and mycorrhizal dependence (MD were measured. The percentage AM colonization of A. malaccensis and A. crasna ranged from 83 to 97% and from 63 to 78%, respectively. Colonization by five AM fungi increased plant height, diameter, and shoot and root dry weights. N and P content of  the seedlings were also increased by AM colonization. Survival rates were higher in the AM-colonized seedlings at 180 days after transplantation than those in the control seedlings. The MD of Aquilaria species was higher than 55 %. The results suggested that AM fungi can be inoculated`to Aquilaria species under nursery conditions to obtain vigorous seedlings, and the field experiment is underway to clarify the role of AM fungi under field conditions.

Effect of endomycorrhizae on the bioavailability of bound 14C residues to onion plants from an organic soil treated with [14C]fonofos

International Nuclear Information System (INIS)

Nelson, S.D.; Khan, S.U.

1990-01-01

Uptake of bound 14 C residues from an organic soil treated with radiolabeled fonofos (O-ethyl S-phenyl ethylphosphonodithioate) by selected Glomus endomycorrhiza and onion roots was studied. The hyphae of endomycorrhizal associations were capable of removing 14 C residues from the soil and transporting them to onion plants. Bioavailability of soil-bound 14 C residues, as measured by 14 C residue content in onion, was increased 32 and 40% over that of nonmycorrhizal plants by hyphae of Glomus intraradices and Glomus vesiculiferium, respectively. The data suggest that under field conditions endomycorrhizal infection may greatly increase the bioavailability of soil-bound pesticide residues to plants

Paraganglioma of the head and neck region: treatment outcome and toxicity

International Nuclear Information System (INIS)

Ramakrishna, Naren; Bhaddy, Nasir; Holliday, Michael; Lee, D.-J.

1997-01-01

Purpose: To evaluate the long term results of treating paraganglioma (glomus tumor) of the head and neck region, in terms of local control and toxicities. Materials and Methods: We retrospectively reviewed the records of 38 patients with a diagnosis of a paraganglioma of the head and neck region who had received their therapy at our hospital from 1972 to 1994. Nine patients received definitive radiotherapy (XRT), 7 had surgical resection plus postoperative XRT and 22 patients had surgical resection only. There were 11 males and 27 females. The median age was 50 years with a range of 15 to 78. XRT, either definitive or postoperative, consisted of 1.8 Gy per fraction to a total of 45 to 50.4 cGy. In terms of surgery for the postoperative XRT group, resection of the glomus tumor in the neck or temporal bone was carried out in 6, and in one patient additional suboccipital craniotomy (2-staged) for removal of the intracranial portion of the tumor was performed. For the surgery alone group, 18 patients had resection of the glomus tumor in the neck or temporal bone, and 4 patients required additional two-staged suboccipital craniotomy. Results: In the XRT group, 14 patients had glomus jugulare and 2 patients had glomus typanicum tumor. With a median follow-up of 5 years (range: 2 to 21), one of the 16 patients developed local recurrence. In the surgery only group (15 glomus jugulare, 4 glomus typanicum and 3 glomus vegalis), 5 of the 22 patients developed local recurrence, with a median follow-up of 6 years (range: 2 to 15). The difference in the local control rates was not statistically significant (Fisher's test, p= 0.18). XRT was well tolerated. One patient developed facial nerve paralysis 5 years following XRT. Whereas in the surgery only group, the long term sequela was mainly cranial nerve dysfunction which affected the facial nerve in 2, the facial nerve plus the lingual nerve in one and facial plus cranial nerves VI, IX and XII in another (p=0.28). Conclusion

The application of isotopic (32P and 15N) dilution techniques to evaluate the interactive effect of phosphate-solubilizing rhizobacteria, mycorrhizal fungi and Rhizobium to improve the agronomic efficiency of rock phosphate for legume crops

International Nuclear Information System (INIS)

Barea, J.M.; Toro, M.; Azcon, R.; Orozco, M.O.; Campos, E.; Azcon, R.

2002-01-01

A pot experiment was designed to evaluate the interactive effects of multifunctional microbial inoculation treatments and rock phosphate (RP) application on N and P uptake by alfalfa through the use of 15 N and 32 P isotopic dilution approaches. The microbial inocula consisted of a wild type (WT) Rhizobium meliloti strain, the arbuscular mycorrhizal (AM) fungus Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, and a phosphate solubilizing rhizobacterium (Enterobacter sp.). Inoculated microorganisms were established in the root tissues and/or in the rhizosphere soil of alfalfa plants (Medicago sativa L.). Improvements in N and P accumulation in alfalfa corroborate beneficial effects of Rhizobium and AM interactions. Inoculation with selected rhizobacteria improved the AM effect on N or P accumulation in both the RP-added soil and in the non RP-amended controls. Measurements of the 15 N/ 14 N ratio in plant shoots indicate an enhancement of the N 2 fixation rates in Rhizobium-inoculated AM-plants, over that achieved by Rhizobium in non-mycorrhizal plants. Whether or not RP was added, AM-inoculated plants showed a lower specific activity ( 32 P/ 31 P) than did their comparable non-mycorrhizal controls, suggesting that the plant was using otherwise unavailable P sources. The phosphate-solubilizing, AM-associated, microbiota could in fact release phosphate ions, either from the added RP or from the indigenous 'less-available' soil phosphate. A low Ca concentrations in the test soil may have benefited P solubilization. Under field conditions, the inoculation with AM fungi significantly increased plant biomass and N and P accumulation in plant tissues. Phosphate-solubilizing rhizobacteria improved mycorrhizal responses in soil dually receiving RP and organic matter amendments. Organic matter addition favoured RP solubilization. This, together with a tailored microbial inoculation, increased the agronomic efficiency of RP in the test soil that was Ca deficient at neutral

Effect of mycorrhizal inoculation on the growth and phytoextraction of heavy metals by maize grown in oil contaminated soil

International Nuclear Information System (INIS)

Achakzai, A.K.K.; Liasu, M.O.; Popoola, O.J.

2011-01-01

Pot experiments were conducted to investigate the effect of AM (Glomus mosseae ) fungi inoculation (M) on the growth of maize and phyto extraction of selected heavy metals from a soil contaminated with crude oil (C). Four soil treatments, each with three replicates i.e., C/sup +/M/sup +/, M/sup +/, C/sup +/ and control (without oil and inoculum) were conducted. Half of the pots with the soil treatments were planted with singly sown (SS) and the other half with densely sown i.e., four maize seedlings (DS). Various plant growth attributes were measured at weekly intervals Cu/sup 2+/, Ni/sup 2+/, Pb/sup 2+/ and Cd/sup 2+/ in the soil, root and shoot of maize plants were determined separately. Inoculation by AM promoted the vegetative growth attributes in both treatments viz., C/sup +/M/sup +/ and M/+. AM inoculation also promoted the hyper extraction of heavy metals from C/sup +/M/sup +/ soils, but inhibited by soils treated with M/sup +/. High planting density i.e., DS also promoted phyto extraction of heavy metals from uncontaminated (M/sup +/) soils, but had minimal effect on phyto extraction from oil contaminated soils (C/sup +/). Planting density complemented the promotive effect of AM inoculation on phyto extraction of heavy metals from C/sup +/ soils. The hyper extraction of selected metals from soil is more favored by planting density in C/sup +/ soils, whereas AM inoculation tends to exclude heavy metals from potted plants. However, in case of C/sup +/M/sup +/ soils, AM inoculation promotes the hyper extraction of metals more than planting density. While the combination of the two phenomena act synergistically to promote metal hyper extraction from C/sup +/M/sup +/ as well as M/sup +/ soils. (author)

Changes in soil solution Zn and pH and uptake of Zn by arbuscular mycorrhizal red clover in Zn-contaminated soil.

Science.gov (United States)

Li, X; Christie, P

2001-01-01

Red clover plants inoculated with Glomus mosseae were grown in a sterile pasture soil containing 50 mg Zn kg(-1) in 'Plexiglas' (acrylic) containers with nylon net partitions (30 microm mesh) designed to separate the soil into a central root zone and two outer zones for hyphal growth with no root penetration. Two porous plastic soil moisture samplers were installed in each pot, one in the root compartment and the other in one of the hyphal compartments. The soil in the outer compartments was amended with one of the four application rates of Zn (as ZnSO4) ranging from 0 to 1000 mg kg(-1). Non-mycorrhizal controls were included, and there were five replicates of each treatment in a randomised block in a glasshouse. Uninoculated plants received supplementary P to avoid yield limitation due to low soil P status. Plants grew in the central compartment for nine weeks. Soil moisture samples were collected 4, 24 and 62 days after sowing to monitor changes in the Zn concentration and pH of the soil solution. At harvest, the mean mycorrhizal infection rate of inoculated plants ranged from 29% to 34% of total root length and was little affected by Zn application. Root and shoot yields were not affected by mycorrhizal infection. Plant Zn concentration and uptake were lower in mycorrhizal plants than non-mycorrhizal controls, and this effect was more pronounced with increasing Zn application rate to the soil. Soil solution Zn concentrations were lower and pH values were higher in mycorrhizal treatments than non-mycorrhizal controls and the mycorrhiza effect was more pronounced at higher Zn application rates. The protective effect of mycorrhiza against plant Zn uptake may have been associated with changes in Zn solubility mediated by changes in the soil solution pH, or by immobilisation of Zn in the extraradical mycelium.

Effect of arbuscular mycorrhizal fungi and multi-combination of bioinoculants on regenerated seedlings of cotton

International Nuclear Information System (INIS)

Pindi, P.K.; Sultana, T.

2014-01-01

Effect of arbuscular mycorrhizal fungi and multi-combination of bioinoculants on regenerated seedlings of cotton Cotton, referred as 'The white gold' is an important commercial crop in India and stands third in the world by means of area of cultivation. Cotton plant regeneration from callus by somatic embryogenesis and its efficiency has been improved significantly in recent times. Our primary investigation was on regenerative studies and multiple shoot induction system focusing mainly on meristematic tissues like seedling cotyledonary nodal explants in RAH-9750 cotton cultivar. An attempt has been made to improve the rate of surveillance and growth of regenerated cotton seedlings by bio-inoculant (mainly AMF) treatment under greenhouse conditions. Out of a total seven pure cultures of AMF fungi, R1-R2 have shown maximum mycorrhizal colonization with RAH-9750 (R) and was identified as Glomus mosseae. This variety was also tested with three different bioinoculants i.e., Rhizobium sp. RHPU-7, Azospirillum sp. PPK-27, Bacillus sp. PU-1, apart from AMF R1-R2 in different combinations. The cotton seedlings have shown the best results in single, dual, triple and multiple combinations i.e R+R1-R2, R+R1-R2+Rhizobium, R+R1-R2+Rhizobium+Azospirillum and R+R1-R2+Rhizobium+Azospirillum+Bacillus respectively. The growth of cotton plants (RAH-9750) generated from meristematic tissue culture was found to be increasing significantly when compared with the normal seeds. Similar results were noticed when the same experiment was subjected to the different soil types of Mahabubnagar district. The investigation clearly infers that better yield of cotton RAH-9750 (R) could be achieved by treating the regenerated cotton seedlings with bioinoculants in different combination in various soil types of Mahabubnagar district. (author)

Arbuscular mycorrhizal fungi facilitate the invasion of Solidago canadensis L. in southeastern China

Science.gov (United States)

Yang, Ruyi; Zhou, Gang; Zan, Shuting; Guo, Fuyu; Su, Nannan; Li, Jing

2014-11-01

The significance of arbuscular mycorrhizal fungi (AMF) in the process of plant invasion is still poorly understood. We hypothesize that invasive plants would change local AMF community structure in a way that would benefit themselves but confer less advantages to native plants, thus influencing the extent of plant interactions. An AMF spore community composed of five morphospecies of Glomus with equal density (initial AMF spore community, I-AMF) was constructed to test this hypothesis. The results showed that the invasive species, Solidago canadensis, significantly increased the relative abundance of G. geosperum and G. etunicatum (altered AMF spore community, A-AMF) compared to G. mosseae, which was a dominant morphospecies in the monoculture of native Kummerowia striata. The shift in AMF spore community composition driven by S. canadensis generated functional variation between I-AMF and A-AMF communities. For example, I-AMF increased biomass and nutrient uptake of K. striata in both monocultures and mixtures of K. striata and S. canadensis compared to A-AMF. In contrast, A-AMF significantly enhanced root nitrogen (N) acquisition of S. canadensis grown in mixture. Moreover, mycorrhizal-mediated 15N uptake provided direct evidence that I-AMF and A-AMF differed in their affinities with native and invading species. The non-significant effect of A-AMF on K. striata did not result from allelopathy as root exudates of S. canadensis exhibited positive effects on seed germination and biomass of K. striata under naturally occurring concentrations. When considered together, we found that A-AMF facilitated the invasion of S. canadensis through decreasing competitiveness of the native plant K. striata. The results supported our hypothesis and can be used to improve our understanding of an ecosystem-based perspective towards exotic plant invasion.

Effects of organic, biological and chemical fertilizers on vegetative indices and essential oil content of coriander (Coriandrum sativum L.

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M Aghhavani Shajari

2016-05-01

Full Text Available This experiment was conducted to study the effects of single and combined application of organic, biological and chemical fertilizers on qualitative and quantitative characteristics of vegetative part of coriander, (Coriandrum sativum L.. The experiment was carried out as split plot in time based on Complete Randomized Block Design with three replications and 12 treatments at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during growing season of 2010-2011. Treatments included: (1 mycorrhiza (Glomus mosseae, (2 biosulfur (Thiobacillus sp., (3 chemical fertilizer (NPK, (4 cow manure, (5 vermicompost, (6 mycorrhiza + chemical fertilizer, (7 mycorrhiza + cow manure, (8 mycorrhiza + vermicompost, (9 biosulfur + chemical fertilizer, (10 biosulfur + cow manure, (11 biosulfur + vermicompost and (12 control. Vegetative parts of coriander were cut at 5% of flowering stage in two dates (19 May and 5 June. Results showed that the highest plant height (28 cm and lateral branches (5.2 were obtained in combined application of biosulfur with cow manure treatment. The highest fresh and dry leaf weight, fresh and dry matter yield and stem dry matter weight were obtained in single application of chemical fertilizer. Single application of biosulfur increased leaf/stem ratio. The highest essential oil percentage and essential oil yield were observed in cow manure treatment (0.2% and 1753 g.ha-1, respectively. The maximum leaf/stem ratio were observed in the first cutting, while the highest lateral branches, stem fresh and dry matter yield, essential oil percentage and essential oil yield were obtained in second cut. Overall, results of this study showed that the plant vegetative yield increased by using chemical fertilizer, while essential oil percentage and essential oil yield of coriander were improved by using organic and biological fertilizers.

Effects inoculation of mycorhizae species and irrigation levels impacts on growth criteria, yield and water use efficiency of corb (Zea mays L.

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M.R. Amerian

2016-05-01

Full Text Available Water deficiency is one of the most important factors for limiting crop yield in arid and semiarid regions. Symbiosis with a variety of microorganisms in these regions is one of the modern ecological approaches for sustainable agriculture to reduce damages caused by environmental stresses. Symbiotic of arbuscular mycorrhizal fungi (AM with the roots of crops has shown positive effects on agricultural systems. In order to study the effects of inoculation with two species of mycorrhizal fungi and irrigation levels on root growth criteria and water use efficiency of corn, an experiment was performed as split plots based on a complete randomized block design with three replications at the Agricultural Research Station, Ferdowsi University of Mashhad during growing season of 2008-2009. Treatments included two mycorhizae inoculation (Glomus mosseae and G. intraradices and control and four irrigation levels (25, 50, 75 and 100% of water requirement. Grain yield, root specific length, the percentage of root colonization and water use efficiency based on grain yield of corn were measured. The results showed that the effect of mycorrhizae inoculation was significant on (p≤0.05 root specific length, grain yield and water use efficiency of corn. Mycorrhizae species had no significant effect on root colonization percentage of corn. Different irrigation levels had significant effect on grain yield, special length root, the percentage of root colonization, and water use efficiency of corn (p≤0.05. Generally, the results showed that mycorrhizae inoculation in water deficiency conditions, can increase the uptake of water and nutrients by developing the root and increasing the absorbing surface. In this way, not only the plant tolerance against the water deficiency increases, but also more yield will be produced for a specific value of water, which means the water use efficiency increases. Furthermore, the use of water will be decreased.

Glomangioma of the knee with no response to sclerotherapy

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Mahboubeh Rahmani, MD

2017-06-01

This case demonstrates that glomus tumors should be considered in the differential diagnosis of vascular lesions which recur after sclerotherapy even in locations not typically associated with glomus tumors such as the knee. This possibility supports the benefit of surgical excision in refractory vascular lesions to support both diagnosis and more definitive treatment.

The Hidden Cost of Untreated Paragangliomas of the Head and Neck: Systemic Reactive (AA Amyloidosis

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Erkan Dervisoglu

2015-01-01

Full Text Available We report a case of a 51-year-old man who was diagnosed with systemic reactive (AA amyloidosis in association with untreated glomus jugulare and glomus caroticum tumors. He refused radiotherapy and renal replacement therapy. Paragangliomas, although rare, should be considered one of the tumors that can result in AA amyloidosis.

Forestación de un terreno decapitado con Robinia pseudoacacia inoculada con Rhizobium spp. y Glomus deserticola Afforestation of a desurfaced field with Robinia pseudoacacia inoculated with Rhizobium spp. and Glomus deserticola

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Alejandro E Ferrari

2010-07-01

Full Text Available Los terrenos decapitados constituyen un caso extremo de degradación de suelos aptos para agricultura, con graves consecuencias ambientales. El propósito de este trabajo fue ensayar los efectos de la inoculación de acacia blanca (Robinia pseudoacacia L. con una cepa efectiva de Rhizobium y un hongo de micorrizas arbusculares (Glomus deserticola en la supervivencia y crecimiento temprano de plantas trasplantadas a un terreno decapitado de Balcarce, comparando con fresno como árbol no fijador de nitrógeno. La supervivencia inicial fue muy buena (mayor del 77%, especialmente para los fresnos y las acacias inoculadas, las cuales mostraron significativamente mayor supervivencia al estrés por sequía que las acacias control. Todas las plantas se mostraron igualmente tolerantes al ataque de liebres y al estrés por heladas tardías. Durante el primer año las acacias inoculadas crecieron más rápido que las no inoculadas. En el segundo año las alturas se equipararon en parte, probablemente por la colonización de las acacias control con rizobios o micorrizas naturales del suelo. De todos modos, las acacias inoculadas siempre mostraron valores mayores de los distintos parámetros de desarrollo (altura total, diámetro de la copa y cantidad de ramificaciones que las plantas control, tanto en los sectores poco decapitados como en los más severamente degradados. En conclusión, la doble inoculación previa de acacia blanca mejoró la supervivencia inicial, aumentó tolerancia a la sequía y el crecimiento en 2 años y medio desde la plantación. Esta práctica de manejo sería entonces muy recomendable para reducir el período de vivero en la producción de árboles, así como lograr ejemplares más resistentes y mejor adaptados para proyectos de recuperación de suelos degradados.Many agricultural lands in Buenos Aires Province (Argentina have traditionally been desurfaced for the manufacture of bricks and other building materials. The desurfaced

The distribution of vesicular-arbuscular mycorrhizal fungi in India.

Science.gov (United States)

Rani, R; Mukerji, K G

1990-01-01

Vesicular-arbuscular mycorrhizal fungi are widely distributed throughout the area studied including different altitudes ranging from sea level to 2500 ft above sea level. VAM fungi were recorded from 88% of the sites examined with Glomus fasciculatum and Glomus macrocarpum being the most commonly recorded. Mean species diversity was found to be maximum in the areas thickly vegetated and undisturbed.

Oral Ketamine in the Palliative Care Setting: A Review of the Literature and Case Report of a Patient With Neurofibromatosis Type 1 and Glomus Tumor-Associated Complex Regional Pain Syndrome

Science.gov (United States)

Soto, Eliezer; Stewart, Douglas R.; Mannes, Andrew J.; Ruppert, Sarah L.; Baker, Karen; Zlott, Daniel; Handel, Daniel; Berger, Ann M.

2014-01-01

Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has been shown to be effective not only for its anesthetic properties but also for the analgesic and opiate-sparing effects. However, data on efficacy and safety of oral ketamine for the treatment of neuropathic or cancer pain syndromes is limited with most of the evidence based on small clinical trials and anecdotal experiences. In this review, we will analyze the clinical data on oral ketamine in the palliative care setting. After an extensive search using five major databases, a total of 19 relevant articles were included. No official clinical guidelines for the use of oral ketamine in this patient population were found. Studies on oral ketamine for cancer and neuropathic pain have shown mixed results which could be partially due to significant differences in hepatic metabolism. In addition, we will include a case report of a 38-year-old female with neurofibromatosis type 1 (NF1) with history of chronic, severe pain in her fingertips secondary to multiple glomus tumors which evolved into CRPS resistant to multiple therapies but responsive to oral ketamine. Based on our experience with oral ketamine, this drug should be administered after an intravenous trial to monitor response and side effects in patients with an adequate functional status. However, patients in the palliative care and hospice setting, especially the one at the end of their lives, may also benefit from oral ketamine even if an intravenous trial is not feasible. PMID:21803784

Redox signaling in acute oxygen sensing

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Lin Gao

2017-08-01

Full Text Available Acute oxygen (O2 sensing is essential for individuals to survive under hypoxic conditions. The carotid body (CB is the main peripheral chemoreceptor, which contains excitable and O2-sensitive glomus cells with O2-regulated ion channels. Upon exposure to acute hypoxia, inhibition of K+ channels is the signal that triggers cell depolarization, transmitter release and activation of sensory fibers that stimulate the brainstem respiratory center to produce hyperventilation. The molecular mechanisms underlying O2 sensing by glomus cells have, however, remained elusive. Here we discuss recent data demonstrating that ablation of mitochondrial Ndufs2 gene selectively abolishes sensitivity of glomus cells to hypoxia, maintaining responsiveness to hypercapnia or hypoglycemia. These data suggest that reactive oxygen species and NADH generated in mitochondrial complex I during hypoxia are signaling molecules that modulate membrane K+ channels. We propose that the structural substrates for acute O2 sensing in CB glomus cells are “O2-sensing microdomains” formed by mitochondria and neighboring K+ channels in the plasma membrane. Keywords: Hypoxia, Acute oxygen sensing, Peripheral chemoreceptors, Carotid body, Adrenal medulla, Mitochondrial complex I, Reactive oxygen species (ROS, Pyridine nucleotides

Effects of Vermicompost and Mycorrhizal Fungi on Growth Characteristics, Essential Oil and Yield of Thyme (Thymus vulgaris L.

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Naeemeh Bitarafan

2017-09-01

Full Text Available Introduction Thyme (Thymus vulgaris L. is one of the most important essential oil plants that its essential oil constituent be used in different medicinal and food industries. Vermicompost is organic manure that significant amounts of macro and micronutrients make available to the plants. Although some of this material is minerals but most of them gradually and slowly released through the mineralization of organic matter. Mycorrhizal fungi are one of the biological factors in the rhizosphere, which include a relatively important part of soil organisms. Under water deficit conditions, mycorrhiza enhances photosynthesis and carbon fixation during the growing season by increasing the leaf area. This condition does not directly contribute to increased photosynthesis in the host plant, but keeps the photosynthesis level higher than control by improving water relations and changing the hormonal relations. Materials and methods The treatments included vermicompost in four levels (0, 2, 4, and 6 ton.ha-1 and mycorrhiza in three levels (without inoculation, inoculation with Glomus mosseae and Glomus intraradices was arranged based on randomized complete block design with 12 treatments and 3 replications. Fresh leaf tissue was used to measure chlorophyll content. Dimethyl sulfoxide (7 ml was added to 0.1 g leaf tissue and the samples were incubated at 70°Cfor 4h. The light absorptance was measured at 663, 645 and 470 nm with spectrophotometer (Jenway, 6305 to obtain chlorophyll content. To measure Arbuscular Mycorrhizal (AM symbiosis, plant roots were collected one week before harvesting, cleaned by 10% KOH at 80˚C for 2h, and acidified in 1% HCL for 60 min. Then the cleaned up roots were stained in a solution of trypan blue. The roots were destained in a mixture of 500 ml glycerol, 450 ml water and 5 ml HCL for 24 h, allowing the fungus to be revealed under microscopic examination (Taylor et al. 2008. Statistical analysis: Analysis of variance (ANOVA

Glomangiomatosis: a case report

Energy Technology Data Exchange (ETDEWEB)

Fitzhugh, Valerie A. [Rutgers, the State University of New Jersey-New Jersey Medical School, Department of Pathology and Laboratory Medicine, Newark, NJ (United States); Beebe, Kathleen S. [Rutgers, the State University of New Jersey-New Jersey Medical School, Department of Orthopaedics, Newark, NJ (United States); Wenokor, Cornelia; Blacksin, Marcia [Rutgers, the State University of New Jersey-New Jersey Medical School, Department of Radiology, Newark, NJ (United States)

2017-10-15

Glomangiomatosis is a benign vascular variant of a glomus tumor. The lesion represents only 5% of glomus tumors with unusual or atypical features and even fewer glomus tumors with typical features. The lesions are most commonly located in the distal extremities and are multiple, deep, extensive, and often pain producing. They develop from small arteriovenous anastamoses and are most often identified in young adults. The lesions may recur. We present a case of a 33-year-old male who presented clinically with multiple slowly enlarging masses of the leg over a 5-year period, of which one caused significant pain. One of the lesions was reported to be present at birth. Imaging studies were performed and were suggestive of neurofibromatosis. Biopsies from multiple lesions led to an eventual diagnosis of multiple glomangiomatosis. (orig.)

Réponse du fonio blanc (Digitaria exilis Stapf) à l'inoculation avec ...

African Journals Online (AJOL)

SARAH

2016-07-31

Jul 31, 2016 ... (2004) a montré que l'inoculation avec des .... fasciculatum - Go: G. mosseae - Gm: G. manihotis - Ge : G. etunicatum - Gv : G. verriculosum. Les barres ..... dépendantes de la symbiose mycorhizienne car leurs ..... hybrid cv.

Inibição da colonização por Bradyrhizobium elkanii mas não por Glomus intraradices em soja pelo ativador de defesa vegetal BTH

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Hoffmann Lúcia Vieira

2001-01-01

Full Text Available O produto BTH controla doenças através da ativação dos mecanismos de resistência de plantas, cujo modo de ação tem sido caracterizado através da identificação de genes ou enzimas ativados durante esta reação. Os mesmos genes e enzimas podem ser ativados como parte da reação das plantas à colonização por microssimbiontes mutualistas. Então, a aplicação de BTH pode inibir também essas simbioses. Um experimento foi conduzido para verificar se BTH tem efeito sobre a colonização de raízes de soja pelos microssimbiontes Glomus intraradices e Bradyrhizobium elkanii. Plantas controle ou inoculadas com o fungo micorrízico ou rizóbio foram tratadas com 20 mL de BTH 25 mg L-1 por meio da aplicação em sementes, via radicular ou via foliar. As plantas que receberam aplicação radicular de BTH tiveram desenvolvimento vegetativo reduzido. A colonização de raízes por B. elkanii foi menor nas plantas que receberam aplicação de BTH via radicular do que naquelas não tratadas ou tratadas por via foliar apenas. A colonização de raízes de soja por G. intraradices não foi afetada por BTH em quaisquer dos modos de aplicação. A aplicação radicular de BTH deve ser evitada na cultura da soja. Não há indício de restrição de aplicação foliar do produto.

Effect of Biofertilizers and Irrigation Intervals on Yield Component and Yield of Fenugreek (Trigonella foenum- graecum L.

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M. Jaberi

2016-02-01

, Azad University, Birjand, Iran, during 2010-2011. Experimental treatments were irrigation intervals in three levels (every 6, 9 and 12 days and biofertilizer in five levels (nitroxin, biophosphorus, and micorhyza fungi G. mosseae, G. intraradices and control-no fertilizer. Fenugreek was planted through furrow in mid-April 2010. The distance between rows and between plants was 30 and 10 cm, respectively. Seeds were covered by Nitroxin (including: Azotobacterchroococcum, Azospirillum lipoferum and Azospirillum brasilense and biophosphrous (including: Pseudomonas fluorescens and then were cultured.They were used at a depth of 2cm below the seed from Glomusintraradiceand Glomus mosseae. Fenugreek was harvested in early July when the plants became yellow and at least 80% of the pods were reached. Statistical analysis of the data was performed using SAS 9.1 and MSTATC. Mean comparison were compared by the Duncan test at 1% and 5% level of probability. Results and Discussion: Results of statistical analysis showed that irrigation treatments and biofertilizers had significant effect on most indices. Interaction effect of irrigation and biofertilizer were significant on seed and leaf yield (p

Evolution of the P-type II ATPase gene family in the fungi and presence of structural genomic changes among isolates of Glomus intraradices

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Sanders Ian R

2006-03-01

Full Text Available Abstract Background The P-type II ATPase gene family encodes proteins with an important role in adaptation of the cell to variation in external K+, Ca2+ and Na2+ concentrations. The presence of P-type II gene subfamilies that are specific for certain kingdoms has been reported but was sometimes contradicted by discovery of previously unknown homologous sequences in newly sequenced genomes. Members of this gene family have been sampled in all of the fungal phyla except the arbuscular mycorrhizal fungi (AMF; phylum Glomeromycota, which are known to play a key-role in terrestrial ecosystems and to be genetically highly variable within populations. Here we used highly degenerate primers on AMF genomic DNA to increase the sampling of fungal P-Type II ATPases and to test previous predictions about their evolution. In parallel, homologous sequences of the P-type II ATPases have been used to determine the nature and amount of polymorphism that is present at these loci among isolates of Glomus intraradices harvested from the same field. Results In this study, four P-type II ATPase sub-families have been isolated from three AMF species. We show that, contrary to previous predictions, P-type IIC ATPases are present in all basal fungal taxa. Additionally, P-Type IIE ATPases should no longer be considered as exclusive to the Ascomycota and the Basidiomycota, since we also demonstrate their presence in the Zygomycota. Finally, a comparison of homologous sequences encoding P-type IID ATPases showed unexpectedly that indel mutations among coding regions, as well as specific gene duplications occur among AMF individuals within the same field. Conclusion On the basis of these results we suggest that the diversification of P-Type IIC and E ATPases followed the diversification of the extant fungal phyla with independent events of gene gains and losses. Consistent with recent findings on the human genome, but at a much smaller geographic scale, we provided evidence

Effect of simultaneous application of mycorrhiza with compost, vermicompost and sulfural geranole on some quantitative and qualitative characteristics of sesame (Sesamum indicum L. in a low input cropping system

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P rezvani moghaddam

2016-03-01

quantitative and qualitative characteristics of sesame (Sesamum indicum L. in a low input cropping system was investigated. Materials and methods In order to evaluate the effects of simultaneous application of mycorrhiza and organic fertilizers on some quantitative and qualitative characteristics of sesame (Sesamum indicum L., an experiment was conducted based on randomized complete block design with three replications at Agricultural Research Farm, Ferdowsi University of Mashhad, Iran during growing season 2009-2010 growing season. Treatments were mycorrhiza (Glomus mosseae, mycorrhiza+compost, mycorrhiza+vermicompost, mycorrhiza+organic sulfural geranole, compost, vermicompost, Organic sulfural geranole and control (no fertilizer. Finally, data analysis was done using SAS 9.1 and means were compared by duncan’s multiple range test at 5% level of probability. Results and discussion The results showed that the effect of different organic and biological fertilizers were significant on seed yield. Seed yield significantly increased by using mycorrhiza in both condition of single and mixed with organic sulfural geranole and vermicompost compared to control treatment. Biological yield, in simultaneous application of vermicompost and organic sulfural geranole with mycorrhiza increased significantly compared to separate use of these fertilizers. All study organic fertilizers with mycorrhiza had significant effect on increasing oil content of sesame. Seed oil increased in simultaneous application of mycorrhiza and each of compost, vermicompost and organic sulfural geranole compared to separate application of mycorrhiza 12, 13 and 10 percentages, respectively. It seems that mycorrhiza and organic fertilizers improved quantitative and qualitative characteristics of sesame due to provide better conditions to absorption and transportation of nutrient to the plant (Hawkes et al., 2008. Conclusion In general, the results showed that the simultaneous use of ecological inputs can improve

The Effects of Arbuscular Mycorrhiza Fungi on Dry Matter and Concentrations of Nitrogen, Phosphorus and Potassium in Berseem Clover, by Cadmium stress

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hashem aram

2016-02-01

Full Text Available Introduction: Soil contaminations with heavy metals represent a potential risk to the biosphere and leads to increased concentration in ground and surface water. Therefore metals mobility in soil has been extensively studied in the last decades. Use of agrochemicals such as synthetic fertilizers and pesticides has resulted in soil and water pollution, and loss of biodiversity. Cadmium is a heavy metal with a strong effect on crop quality. Moreover, it is a very mobile element in the environment. Plants can easily uptake cadmium and transfer it to other organs. Experiments on the effects of cadmium on the contents of macro elements in plants are scarce and therefore the mechanism of its effect has not yet been fully explained. Contaminated soil can be remediated by chemical, physical or biological techniques. Mycorrhiza is the mutualistic symbiosis (non-pathogenic association between soil-borne fungi with the roots of higher plants. Arbuscular mycorrhizal fungi (AMF are obligate biotrophs, which can form mutualistic symbioses with the roots of around 80% of plant species. Arbuscular mycorrhiza have been observed to play a vital role in metal tolerance and accumulation. Many workers have reported enhancement of phosphate uptake and growth of leguminous plants by vesicular arbuscular mycorhizal fungi (AMF. Materials and Methods: One study performed the factorial experiment based on completely randomized design (CRD with three replications in the greenhouse of Agriculture Faculty of Zanjan University. The examined factors include different levels of arbuscular mycorrhizal fungi inoculation (Glomus mosseae (with and without inoculation, and different levels of soil contamination by cadmium (0, 5, 10, 20, 40 and 80 ppm. In this study, arbuscular mycorrhizal fungi Glomus mosseae species were used. These fungi were prepared by the Plant Protection Clinic in Iran – Hamedan. The soil was prepared of arable land of depth of 0-20 cm at the University of

Influência da colonização micorrízica arbuscular sobre a nutrição do quiabeiro Influence of arbuscular mycorrhiza fungi on the nutrition of okra plant

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Ricardo Luís Louro Berbara

1999-09-01

Full Text Available Foram estudados em casa de vegetação alguns parâmetros de crescimento em plantas de quiabo (Abelmoschus esculentus (L. Moench cv. Piranema colonizadas por dois grupos de fungos micorrízicos arbusculares, com o objetivo de determinar a influência dos inóculos na nutrição e morfologia radicular do quiabeiro. Um grupo continha apenas esporos de Acaulospora longula (A enquanto o outro, esporos de oito espécies: Glomus occultum, Glomus aggregatum, Glomus microcarpum, Acaulospora longula, Acaulospora morrowae, Sclerocystis coremioides, Sclerocystis sinuosa, Scutellospora pellucida. As plantas foram submetidas a três níveis de P (0, 10 e 60 kg ha-1 de P2O5 e coletadas em três diferentes idades (22, 32 e 47 dias, com quatro repetições para cada tratamento. Foi determinado o acúmulo de N, P, K, e Mg na raiz e parte aérea, bem como o influxo médio desses elementos e a área radicular. Os resultados indicaram, além da resposta positiva do quiabeiro ao P, uma maior eficiência da inoculação com mistura de espécies apesar de o influxo médio, determinado aos 47 dias, apresentar maiores valores para o tratamento com A. longula.An experiment was carried out in greenhouse to determine the influence of inoculation of two groups of arbuscular mycorrhizae on the nutrition and radicular morphology of the okra plant (Abelmoschus esculentus (L. Moench cv. Piranema. One group had only Acaulospora longula spores and the other a spore mixture of eight species: Glomus occultum, Glomus aggregatum, Glomus microcarpum, Acaulospora longula, Acaulospora morrowae, Sclerocystis coremioides, Sclerocystis sinuosa, Scutellospora pellucida. The experiment was held in greenhouse conditions with three levels of P (0, 10 and 60 kg ha-1 of P2O5, three samplings dates (22, 32 and 47 days and four replications. The accumulation of N, P, K, Ca and Mg in roots and shoots, root area and their influx ratio were determined. The results made evident that the mixture of

Research and transference of the ICES over Malargue, Mendoza, uranium bioremediation

International Nuclear Information System (INIS)

Scotti, A.; Barbero, N.; Castano-Ganan, A.R; Ramires, A.; Ojeda, C.; Meza, Juan C.; Lopez, S.; Salgan, Laura; Diaz Isenrath, G.

2009-01-01

The origin of the International Center for Earth Sciences (ICES) dates back to 2002 when the Acoustic Emission Station on Volcano Peteroa was installed. Up to now, it represents the first of its kind in the entire Andean Cordillera. This scientific activity is jointly coordinated by scientists from Italy and Argentina. At the First Conference on Acoustic Emission held on 2004, a letter of intent for the establishment of ICES was signed. Presently, ICES is composed by 4 departments: Environment and Climate; Anthropology; Environmental and Territorial Environmental Risk; Resources and Exploration Geophysics. One of the primary objectives of ICES is to promoting applied research and development in the broad field of Earth Sciences. The experimental work consists of main 4 steps listed below: The 'Helianthus annus' (sunflower) has proven its ability to raise Uranium (U) in hydroponic systems and was widely used in the model U rizophyiltration extraction of groundwater in Ashtabula, Ohio, USA. Hydroponic trial design consists of 6 treatments and 4 repetitions plants witnesses without minimum level of U, U witnesses plants without and 4 with various levels of U (Stage 1). The Glomus intraradices is a mycorrhizal fungus used in strategies of U phyto-stabilization. Test consists in the cultivation of sunflower with roots inoculated with Glomus intraradices to determine their uptake and translocation of U (Stage 2). The inoculation of 'Glomus intraradices' in 'Helianthus annus' produces an effective symbiosis with the type of strain and its genetic diversity, some genotypes are highly suitable for this. There have been experiences of this kind in the basic research in several countries. In this work, we use the system in 'Helianthus-Glomus' phyto-stabilization or rizophyiltration soil as a strategy for bioremediation of U at the Malargue area, Province of Mendoza (Stage 3). It will launch a pilot test of the transfer plan, which involves creating a garden for the growth of

Study the concentration of macroelements in forage mays (Zea mays L. (SC 704 as effected by inoculation with mycorrhizal fungi and Azotobacter chroococcum under different levels of nitrogen

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M. Amirabadi

2016-05-01

Full Text Available Nitrogen and phosphorus are two necessary macronutrients for plant growth and yield. These two elements now will be added to soil by chemical fertilizers. This research has been carried out based on randomized completely block design with three replications at Markazi Provience Agricultural Research Station, Iran, during growing season of 2004-2005 to evaluate the effects of Azotobacter chroococcum and Mycorrhiza (Glomus intraradices as biofertilizers and urea as chemical fertilizers on concentrations of N, P, K, Na, Ca and crude protein (% in corn (Zea mays L. shoot tissues and dry matter of corn. Azotobacter chroococcum used as two levels (inoculated and uninoculated, mycorrhiza (Glomus intraradices in two levels (inoculated and uninoculated and urea in four levels (0, 75, 150 and 300 kg.ha-1. Results showed that Azotobacter chroococcum affected significantly all studied criteria except of K shoot concentration, but mycorrhizan (Glomus intraradices only had a increasing significantly effect on N, K, Na and Crude protein. The interaction between Azotobacter chroococcum and Mycorrhiza (Glomus intraradices had the most increasing effect on dry matter, N, Na and Crude protein. Therefore, based on our results it can be concluded that in order to prevent polluting the agricultural soil, environmental and other water supplies from nitrogen chemical fertilizers, application of Azotobacter chroococcum or combined with mycorrhizal fungi with 150 kg.ha-1 Urea is recommended.

Enhanced Pb Absorption by Hordeum vulgare L. and Helianthus annuus L. Plants Inoculated with an Arbuscular Mycorrhizal Fungi Consortium.

Science.gov (United States)

Arias, Milton Senen Barcos; Peña-Cabriales, Juan José; Alarcón, Alejandro; Maldonado Vega, María

2015-01-01

The effect of an arbuscular mycorrhizal fungi (AMF) consortium conformed by (Glomus intraradices, Glomus albidum, Glomus diaphanum, and Glomus claroideum) on plant growth and absorption of Pb, Fe, Na, Ca, and (32)P in barley (Hordeum vulgare L.) and sunflower (Helianthus annuus L.) plants was evaluated. AMF-plants and controls were grown in a substrate amended with powdered Pb slag at proportions of 0, 10, 20, and 30% v/v equivalent to total Pb contents of 117; 5,337; 13,659, and 19,913 mg Pb kg(-1) substrate, respectively. Mycorrhizal root colonization values were 70, 94, 98, and 90%, for barley and 91, 97, 95, and 97%, for sunflower. AMF inoculum had positive repercussions on plant development of both crops. Mycorrhizal barley absorbed more Pb (40.4 mg Pb kg(-1)) shoot dry weight than non-colonized controls (26.5 mg Pb kg(-1)) when treated with a high Pb slag dosage. This increase was higher in roots than shoots (650.0 and 511.5 mg Pb kg(-1) root dry weight, respectively). A similar pattern was found in sunflower. Plants with AMF absorbed equal or lower amounts of Fe, Na and Ca than controls. H. vulgare absorbed more total P (1.0%) than H. annuus (0.9%). The arbuscular mycorrizal consortium enhanced Pb extraction by plants.

A legacy of tinnitus: multiple head and neck paragangliomas

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Jeremy J. Turner

2009-12-01

Full Text Available We describe the case of a patient who presented with a right-sided glomus jugulare tumor and bilateral glomus vagale tumors. These proved to be nonmalignant paragangliomas on histopathological analysis. Genetic analysis revealed a germline heterozygous missense mutation (Pro81Leu in the succinate dehydrogenase subunit D (SDHD gene. We discuss the clinical presentations of the familial paraganglioma syndrome type 1, which is caused by mutations in SDHD, and the implications for the clinical diagnosis and care of such patients.

Arbuscular mycorrhizal fungi and Zn accumulation in the metallophytic plant Viola calaminaria (Gingins. Lej.

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O. Fernández-Fernández

2008-01-01

Full Text Available Los hongos micorrízico arbusculares (HMA incrementan la tolerancia a metales en la mayoría de sus plantas hospederas, sin embargo, se conoce poco de su efecto en plantas metalófitas. Los objetivos de esta investigación fueron: 1 determinar la respuesta a la inoculación con dos HMA de Viola calaminaria (Gingins. Lej., una planta endémica de suelos contaminados con metales pesados, y 2 investigar el efecto de la inoculación con HMA en la acumulación de zinc. Se establecieron dos experimentos: El primero duró tres meses y consistió en la inoculación de plantas de V. calaminaria con dos HMA utilizando arena de río como sustrato de crecimiento. El segundo experimento duró dos semanas y consideró el efecto de la inoculación de las plantas procedentes del primer experimento y que se transfirieron a condiciones de hidroponia con diferentes niveles de Zn+2 (50, 200, 300 y 400 mg.litro-1. Los HMA que se estudiaron fueron dos aislados de Glomus mosseae (Nicol. & Gerd. Gerd. & Trappe: BEG-132- y BEG-25, los cuales se aislaron, respectivamente, de suelos contaminados o no con metales pesados. El experimento 1 mostró que las raíces de V. calaminaria se colonizaron por ambos aislados micorrízicos; sin embargo las plantas no presentaron beneficios en relación a crecimiento, desarrollo y nutrición. El segundo experimento mostró que la inoculación incrementó el contenido total de Zn por planta y que el aislado BEG 25 fue el que mayor influencia tuvo. La colonización micorrízica en las raíces de V. calaminaria no se afectó por las concentraciones de Zn. Resulta relevante continuar experimentos de este tipo para conocer si los HMA adaptados a altos contenidos de metales pesados confieren ventajas sobre crecimiento y supervivencia en campo en estas y otras plantas metalíferas.

The application of isotopic ({sup 32}P and {sup 15}N) dilution techniques to evaluate the interactive effect of phosphate-solubilizing rhizobacteria, mycorrhizal fungi and Rhizobium to improve the agronomic efficiency of rock phosphate for legume crops

Energy Technology Data Exchange (ETDEWEB)

Barea, J.M. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain)]. E-mail: jmbarea@eez.csic.es; Toro, M.; Azcon, R. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain); Orozco, M.O. [Instituto de Sistematica y Ecologia, Academia Cubana de Ciencias, Habana (Cuba); Campos, E. [Departamento de Ciencias de la Tierra y Quimica Ambiental Estacion Experimental del Zaidin (CSIC), Granada (Spain); Azcon, R. [Departamento de Microbiologia del Suelo y Sistemas Simbioticos (Spain)

2002-05-15

A pot experiment was designed to evaluate the interactive effects of multifunctional microbial inoculation treatments and rock phosphate (RP) application on N and P uptake by alfalfa through the use of {sup 15}N and {sup 32}P isotopic dilution approaches. The microbial inocula consisted of a wild type (WT) Rhizobium meliloti strain, the arbuscular mycorrhizal (AM) fungus Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, and a phosphate solubilizing rhizobacterium (Enterobacter sp.). Inoculated microorganisms were established in the root tissues and/or in the rhizosphere soil of alfalfa plants (Medicago sativa L.). Improvements in N and P accumulation in alfalfa corroborate beneficial effects of Rhizobium and AM interactions. Inoculation with selected rhizobacteria improved the AM effect on N or P accumulation in both the RP-added soil and in the non RP-amended controls. Measurements of the {sup 15}N/{sup 14}N ratio in plant shoots indicate an enhancement of the N{sub 2} fixation rates in Rhizobium-inoculated AM-plants, over that achieved by Rhizobium in non-mycorrhizal plants. Whether or not RP was added, AM-inoculated plants showed a lower specific activity ({sup 32}P/{sup 31}P) than did their comparable non-mycorrhizal controls, suggesting that the plant was using otherwise unavailable P sources. The phosphate-solubilizing, AM-associated, microbiota could in fact release phosphate ions, either from the added RP or from the indigenous 'less-available' soil phosphate. A low Ca concentrations in the test soil may have benefited P solubilization. Under field conditions, the inoculation with AM fungi significantly increased plant biomass and N and P accumulation in plant tissues. Phosphate-solubilizing rhizobacteria improved mycorrhizal responses in soil dually receiving RP and organic matter amendments. Organic matter addition favoured RP solubilization. This, together with a tailored microbial inoculation, increased the agronomic efficiency of RP in the

Effect of Arbuscular Mycorrhiza Fungi and Pseudomonas fluorescent bactria on Nutrient Uptake of Pistachio Seedling (Pistacia Vera Cv. Qazvini under Four Irrigation Regimes

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A. Shool

2015-01-01

Full Text Available Pistachio is one of the most important products exported from the country, which due to the low rainfall, its production is faced with water deficiency in Iran. One of the strategies adopted to deal with water deficiency and drought stress in recent years is the use of mycorrhizal fungi and phosphate solubilizing bacteria. Therefore, to study the effect of co-inoculation of arbuscular mycorrhizal fungus Glomus mosseae and Pseudomonas fluorescens P52 strain bacteria on nutrient uptake of pistachio seedling (Pistacia vera cv. Qazvini under drought stress, a greenhouse experiment was conducted using four levels of drought stress (%100 Field capacity (FC as control and 75, 50 and 25 %FC and four levels of biofertilizer (plant without mycorrhizae and bacteria as control, mycorrhizae alone (100 gr of mycorrhizal inoculum in every pot, bacteria alone (two ml of the bacterial suspension in every pot and mycorrhizae and bacteria combination (100 gr of mycorrhizal inoculum and two ml of the bacterial suspension in every pot in a completely randomized design as factorial with four replications. The experiment was carried out between the years of 2010 to 2011 on 3-months old seedlings with three seedlings per pot. In this experiment, bacteria inoculation in different levels of drought had no significant effect on root colonization by mycorrhizae, but regardless of bacterial treatment, an increase in drought intensity had a promotive effect on root colonization. The amount of phosphorus was increased using biofertilizer and in many cases the greatest amount of phosphorus was obtained in mycorrhizae and mixed treatments under 25 and 50% FC. The K+ content of shoot was maximum in the mixed treatment. The greatest amount of root Ca+ was recorded under 25% FC. Drought stress caused a significant increase in micronutrients compared with control at 25% of field capacity, but was ineffective in the roots. In conclusion, the results of this study showed that in many

Influence of host plants and soil diluents on arbuscular mycorrhizal fungus propagation for on-farm inoculum production using leaf litter compost and agrowastes

Science.gov (United States)

Arbuscular mycorrhizal (AM) fungi (Claroideoglomus etunicatum NNT10, C. etunicatum PBT03 and Funneliformis mosseae RYA08) were propagated using different culture materials (sterile sandy soil by itself or mixed 1:1 (v/v) with clay-brick granules, rice husk charcoal, or vermiculite) and host plants (...

Fernando De Castro and the discovery of the arterial chemoreceptors

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Constancio eGonzalez

2014-05-01

Full Text Available When De Castro entered the carotid body (CB field, the organ was considered to be a small autonomic ganglion, a gland, a glomus or glomerulus, or a paraganglion. In his 1928 paper, De Castro concluded: In sum, the Glomus caroticum is innervated by centripetal fibers, whose trophic centers are located in the sensory ganglia of the glossopharyngeal, and not by centrifugal [efferent] or secretomotor fibers as is the case for glands; these are precisely the facts which lead to suppose that the Glomus caroticum is a sensory organ. A few pages down, De Castro wrote: The Glomus represents an organ with multiple receptors furnished with specialized receptor cells like those of other sensory organs [taste buds?]…As a plausible hypothesis we propose that the Glomus caroticum represents a sensory organ, at present the only one in its kind, dedicated to capture certain qualitative variations in the composition of blood, a function that, possibly by a reflex mechanism would have an effect on the functional activity of other organs… Therefore, the sensory fiber would not be directly stimulated by blood, but via the intermediation of the epithelial cells of the organ, which, as their structure suggests, possess a secretory function which would participate in the stimulation of the centripetal fibers. In our article we will recreate the experiments that allowed Fernando de Castro to reach this first conclusion. Also, we will scrutinize the natural endowments and the scientific knowledge that drove De Castro to make the triple hypotheses: the CB as chemoreceptor [variations in blood composition], as a secondary sensory receptor which functioning involves a chemical synapse, and as a centre, origin of systemic reflexes. After a brief account of the systemic reflex effects resulting from the CB stimulation, we will complete our article with a general view of the cellular-molecular mechanisms currently thought to be involved in the functioning of this arterial

Fernando de Castro and the discovery of the arterial chemoreceptors

Science.gov (United States)

Gonzalez, Constancio; Conde, Silvia V.; Gallego-Martín, Teresa; Olea, Elena; Gonzalez-Obeso, Elvira; Ramirez, Maria; Yubero, Sara; Agapito, Maria T.; Gomez-Niñno, Angela; Obeso, Ana; Rigual, Ricardo; Rocher, Asunción

2014-01-01

When de Castro entered the carotid body (CB) field, the organ was considered to be a small autonomic ganglion, a gland, a glomus or glomerulus, or a paraganglion. In his 1928 paper, de Castro concluded: “In sum, the Glomus caroticum is innervated by centripetal fibers, whose trophic centers are located in the sensory ganglia of the glossopharyngeal, and not by centrifugal [efferent] or secretomotor fibers as is the case for glands; these are precisely the facts which lead to suppose that the Glomus caroticum is a sensory organ.” A few pages down, de Castro wrote: “The Glomus represents an organ with multiple receptors furnished with specialized receptor cells like those of other sensory organs [taste buds?]…As a plausible hypothesis we propose that the Glomus caroticum represents a sensory organ, at present the only one in its kind, dedicated to capture certain qualitative variations in the composition of blood, a function that, possibly by a reflex mechanism would have an effect on the functional activity of other organs… Therefore, the sensory fiber would not be directly stimulated by blood, but via the intermediation of the epithelial cells of the organ, which, as their structure suggests, possess a secretory function which would participate in the stimulation of the centripetal fibers.” In our article we will recreate the experiments that allowed Fernando de Castro to reach this first conclusion. Also, we will scrutinize the natural endowments and the scientific knowledge that drove de Castro to make the triple hypotheses: the CB as chemoreceptor (variations in blood composition), as a secondary sensory receptor which functioning involves a chemical synapse, and as a center, origin of systemic reflexes. After a brief account of the systemic reflex effects resulting from the CB stimulation, we will complete our article with a general view of the cellular-molecular mechanisms currently thought to be involved in the functioning of this arterial

Growth promoting characteristics of rhizobacteria and AM Fungi for biomass amelioration of Zea mays

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Kumar Manoj

2015-01-01

Full Text Available Plant growth promoting rhizobacteria (PGPR and mycorrhiza were evaluated on the growth (biomass and yield of Zea mays. In the present study, selective rhizospheric PGPR (Azotobacter chroococcum, Pseudomonas aeruginosa, Azospirillum brasilense and Streptomyces sp. and a combination of six strains of arbuscular mycorrhizal fungi (AMF (Acaulospora morrowae, Gigaspora margarita, Glomus constrictum, Glomus mossae, Glomus aggregatum and Scutellospora calospora were isolated and identified with standard methods and 16S rRNA sequence analysis. PGPR and AMF were checked for their growth-promoting behavior under specific treatment conditions. The 30-48-day-old treated plants in all combinations showed a significantly higher mass value. The average dry weight from the shoot was in a range from 41-52% as compared to the control. This increase also translated into a higher mass value of the roots. Overall, an 82% growth rate was observed in terms of height as the consequence of biomass production, specifically in the case of AMF + rhizobacteria combination. We report an efficient, sustainable and cost-effective biofertilizer for enhanced biomass of Z. mays, one of the staple food crops worldwide.

Electron/electron acoustic instability

International Nuclear Information System (INIS)

Gary, S.P.

1987-01-01

The electron acoustic wave becomes a normal mode of an unmagnetized collisionless plasma in the presence of two electron components with similar densities, but strongly disparate temperatures. The characteristic frequency of this mode is the plasma frequency of the cooler electron component. If these two electron components have a relative drift speed several times the thermal speed of the cooler component, the electron/electron acoustic instability may arise. This paper describes the parametric dependences of the threshold drift speed and maximum growth rate of this instability, and compares these with the same properties of the electron/ion acoustic instability. Under the condition of zero current, the electron/ion acoustic instability typically has the lower threshold drift speed, so that observation of the electron/electron acoustic instability is a strong indication of the presence of an electrical current in the plasma

Electronics and electronic systems

CERN Document Server

Olsen, George H

1987-01-01

Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

Electrons, Electronic Publishing, and Electronic Display.

Science.gov (United States)

Brownrigg, Edwin B.; Lynch, Clifford A.

1985-01-01

Provides a perspective on electronic publishing by distinguishing between "Newtonian" publishing and "quantum-mechanical" publishing. Highlights include media and publishing, works delivered through electronic media, electronic publishing and the printed word, management of intellectual property, and recent copyright-law issues…

PERTUMBUHAN KACANG HIAS (Arachis pintoi PADA MEDIA TANAH PASCA PENAMBANGAN BATUBARA YANG DIPERKAYA MIKORIZA, KAPUR DAN PUPUK NPK

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Willie Samodra Laya

2016-09-01

Full Text Available This study aimed to determine the effects of the provision of arbuscular mycorrhizal fungi (AMF, the provision of lime, and the provision of NPK fertilizer, and the interaction effect of the provision of Arbuscular mycorrhizal fungi (AMF, lime and NPK fertilizers in promoting the growth of pinto peanut in the soil media of post-mining land. The research method used was a completely randomized design (CRD three-factor factorial with the first factor is the type of inoculant FMA (M = 3 levels, the second factor is the provision of lime (K = 3 levels, and the third factor is the NPK fertilizer (P = 3 levels. These results indicated that the interaction between AMF Glomus sp. and NPK fertilizer dose of 1 gram/polybag can increase height increase pinto peanut plants for 34.16 % of the controls. The interaction between AMF Gigaspora sp. The lime dose of 50 % Al-dd and Fertilizers NPK dose of 1 gram/polybag can increase the growth of leaves pinto peanut plants at 108.33 % of the controls. The interaction between AMF Glomus sp. and NPK fertilizer dose of 2 grams/polybag can increase canopy and root biomass pinto peanut plants at 245.21 % of the controls. The interaction between AMF Glomus sp. and NPK fertilizer dose of 2 grams/polybag can increase canopy and root biomass pinto peanut plants at 245.21 % of the controls. Level relative mycorrhizal dependency (RMD was influenced by the type of AMF plant inoculated host. Highest RMD shown in pinto peanut using AMF Glomus sp. is 31.99% at moderately dependent.

Electron-electron Bremsstrahlung for bound target electrons

International Nuclear Information System (INIS)

Haug, E.

2008-01-01

For the process of electron-electron (e-e) Bremsstrahlung the momentum and energy distributions of the recoiling electrons are calculated in the laboratory frame. In order to get the differential cross section and the photon spectrum for target electrons which are bound to an atom, these formulae are multiplied by the incoherent scattering function and numerically integrated over the recoil energy. The effect of atomic binding is most pronounced at low energies of the incident electrons and for target atoms of high atomic numbers. The results are compared to those of previous calculations. (authors)

Colonização e crescimento de mudas de café inoculadas com fungo micorrízico arbuscular em solos com doses de P e umidades controladas

OpenAIRE

Moreira, Samuel Dias

2014-01-01

Os fungos micorrízicos arbusculares (FMA) são capazes de estimular o crescimento das plantas, sobre tudo pelo efeito na nutrição mineral e hidratação, onde possibilita maior absorção de água e nutrientes. Objetivou-se com esse trabalho avaliar a colonização e o crescimento de plantas de café inoculadas com FMA em solos com doses de fósforo (P) e diferentes umidades. Foram produzidas mudas de café (Coffea arabica) micorrizadas utilizando inóculos contendo esporos de Glomus calrum, Glomus etuni...

Fungos micorrízicos vesículo-arbusculares em rizosferas de plantas em dunas do Parque Estadual da Ilha do Cardoso, São Paulo, Brasil: (1 Taxonomia Vesicular-arbuscular mycorrhizal fungi from rhizospheres of dunes plants of Parque Estadual da Ilha do Cardoso, São Paulo State, Brazil (1: taxonomy

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S. F. B Trufem

1989-01-01

Full Text Available De março/1988 a março/1989, mensalmente, foram coletadas o total de 450 amostras de solo de rizosferas de plantas de dunas do Parque Estadual da Ilha do Cardoso, Estado de Sáo Paulo, com a finalidade de se verificar a ocorrência de fungos micorrízicos vesículo-arbusculares (MVA. As plantas mais constantemente investigadas foram: Baccharis trimera DC. (Compositae, Blutaparon portulacoides (St. Hü. Mears (Amaranthaceae, Dalbergia hecastaphylla (L. Taub. (Legurninosae, Hydrocotyle bonariensis Lam. (Umbelliferae,Ipomoeapes-caprae (L.Sweet(Convolvulaceae, Polygaid cyparisseas St. Hül & Moq. (Polygalaceae, além de gramíneas, ciperáceas e outras, que foram coletadas mais esporadicamente. O solo foi tratado pela técnica de decantação e peneiramento em via úmida. Foram verificados 14 taxons de fungos MVA: Acaulospora scrobiculata Trappe, Acaulospora tuberculata Janos & Trappe, Cigaspora gigantea (Nicol. & Gerd. Gerd. & Trappe, Glomus fasciculatum (Thaxter Gerd. & Trappe emend. Walker & Koske, Glomus globiferum Koske & Walker, Glomus monosporum Gerd. & Trappe, Sclerocystis sinuosa Gerd. & Bakshi, Scutellospora calospora (Nicol & Gerd Walker & Sanders, Scutellospora coralloidea (Trappe, Gerd. & Ho (Walker & Sanders, Scutellospora gilmorei (Trappe & Gerd. Walker & Sanders, Scutellospora gregaria (Schenck & Nicol. Walker & Sanders, Scutellospora pérsica (Koske & Walker Walker & Sanders, Scutellospora verrucosa Koske & Walker Walker & Sanders e Scutellospora sp. São apresentadas descrições taxonómicas, comentarios e murônimos dos taxons verificados.Monthly, from March/1988 to March/1989 were collected the total of 450 soil samples from rhizospheres of plants from dunes of Parque Estadual da Ilha do Cardoso, São Paulo State, Brazil, to report the occurrence of VANÍ fungus. The investigated plants were: Baccharis trímera DC. (Compositae, Blutaparon portulacoides (St. Hil. Mears (Amaranthaceae, Dalbergia hecastaphylla (L. Taub

Effect of arbuscular mycorrhizal fungal inoculation on growth, and ...

African Journals Online (AJOL)

The aim of our work was to assess the effect of inoculation with three arbuscular mycorrhizal fungi (AMF) (Rhizoglomus aggregatum (N.C. Schenck and G.S. Sm.) Sieverd., G.A. Silva and Oeh., Funneliformis mosseae (T.H. Nicolson and Gerd.) C. Walker and A. Schüssler. and Rhizoglomus intraradices (N.C. Schenck and ...

Interplay between electron-phonon and electron-electron interactions

International Nuclear Information System (INIS)

Roesch, O.; Gunnarsson, O.; Han, J.E.; Crespi, V.H.

2005-01-01

We discuss the interplay between electron-electron and electron-phonon interactions for alkali-doped fullerides and high temperature superconductors. Due to the similarity of the electron and phonon energy scales, retardation effects are small for fullerides. This raises questions about the origin of superconductivity, since retardation effects are believed to be crucial for reducing effects of the Coulomb repulsion in conventional superconductors. We demonstrate that by treating the electron-electron and electron-phonon interactions on an equal footing, superconductivity can be understood in terms of a local pairing. The Jahn-Teller character of the important phonons in fullerides plays a crucial role for this result. To describe effects of phonons in cuprates, we derive a t-J model with phonons from the three-band model. Using exact diagonalization for small clusters, we find that the anomalous softening of the half-breathing phonon as well as its doping dependence can be explained. By comparing the solution of the t-J model with the Hartree-Fock approximation for the three-band model, we address results obtained in the local-density approximation for cuprates. We find that genuine many-body results, due to the interplay between the electron-electron and electron-phonon interactions, play an important role for the the results in the t-J model. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Symbiotic interaction of endophytic bacteria with arbuscular mycorrhizal fungi and its antagonistic effect on Ganoderma boninense.

Science.gov (United States)

Sundram, Shamala; Meon, Sariah; Seman, Idris Abu; Othman, Radziah

2011-08-01

Endophytic bacteria (Pseudomonas aeruginosa UPMP3 and Burkholderia cepacia UMPB3), isolated from within roots of oil palm (Elaeis guineensis Jacq.) were tested for their presymbiotic effects on two arbuscular mcorrhizal fungi, Glomus intraradices UT126 and Glomus clarum BR152B). These endophytic bacteria were also tested for antagonistic effects on Ganoderma boninense PER 71, a white wood rot fungal pathogen that causes a serious disease in oil palm. Spore germination and hyphal length of each arbuscular mycorrhizal fungal (AMF) pairing with endophytic bacteria was found to be significantly higher than spores plated in the absence of bacteria. Scanning electron microscopy (SEM) showed that the endophytic bacteria were scattered, resting or embedded on the surface hyaline layer or on the degraded walls of AMF spores, possibly feeding on the outer hyaline spore wall. The antagonistic effect of the endophytic bacteria was expressed as severe morphological abnormalities in the hyphal structures of G. boninense PER 71. The effects of the endophytic bacteria on G. boninense PER 71 hyphal structures were observed clearly under SEM. Severe inter-twisting, distortion, lysis and shriveling of the hyphal structures were observed. This study found that the effect of endophytic bacteria on G. intraradices UT126 and G. clarum BR152B resembled that of a mycorrhiza helper bacteria (MHB) association because the association significantly promoted AMF spore germination and hyphal length. However, the endophytic bacteria were extremely damaging to G. boninense PER 71.

Effects of Single and Combined Application of Organic, Biological and Chemical Fertilizers on Quantitative and Qualitative Yield of Coriander (Coriandrum sativum

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M. Aghhavani Shajari

2016-07-01

Full Text Available Introduction: Medicinal plants were one of the main natural resources of Iran from ancient times. Coriander (Coriandrum sativum L. is from Apiaceae family that it has cultivated extensively in the world. Management and environmental factors such as nutritional management has a significant impact on the quantity and quality of plants. Application of organic fertilizers in conventional farming systems is not common and most of the nutritional need of plants supply through chemical fertilizers for short period. Excessive and unbalanced use of fertilizers in the long period, reduce crop yield and soil biological activity, accumulation of nitrates and heavy metals, and finally cause negative environmental effects and increase the cost of production. The use of bio-fertilizers and organic matter are taken into consideration to reduce the use of chemical fertilizers and increase the quality of most crops. Stability and soil fertility through the use of organic fertilizers are important due to having most of the elements required by plants and beneficial effects on physical, chemical, biological and soil fertility. Therefore, the aim of this research was to evaluate the effects of organic, biological and chemical fertilizers on quality and quantity characteristics of coriander. Materials and Methods: In order to study the effects of single and combined applications of organic, biological and chemical fertilizers on quantitative and qualitative characteristics of Coriander (Coriandrum sativum, an experiment was conducted based on a randomized complete block design with three replications and 12 treatments at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in - 2011. Treatments included: (1 mycorrhizae (Glomus mosseae (2 biosulfur (Thiobacillus sp., (3 chemical fertilizer (NPK, (4 cow manure, 5( vermin compost, 6( mycorrhizae + chemical fertilizer, 7( mycorrhizae + cow manure, 8( mycorrhizae + vermicompost, 9( biosulfur

Caso para diagnóstico Case for diagnosis

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Valdilene Loures de Souza

2006-08-01

Full Text Available Tumor glômico é neoplasia benigna originada de células glômicas que circundam anastomoses arteriovenosas e têm função de reguladores de temperatura. São classificados em solitários e múltiplos, adquiridos ou congênitos e histopatologicamente em tumor glômico sólido propriamente dito, glomangioma e glomangiomioma. Os glomangiomas congênitos são extremamente raros, com menos de 20 casos documentados na literatura mundial. Descreve-se caso de glomangioma congênito múltiplo em recém-nato, com regressão parcial espontânea após seis meses de acompanhamento.Glomus tumors are benign lesions that are derived from the glomus cells surrounding arteriovenous anastomoses that serve as temperature regulators. They can be classified into solitary and multiple, acquired or congenital and, histopathologically, into 3 variants: glomus tumor proper, glomangioma and glomangiomyoma. Congenital glomangiomas are extremely rare and less than 20 cases have been documented in the world literature. We report a case of congenital multiple glomangioma present from birth with spontaneous partial regression after six months of follow-up.

Electronic emission and electron guns

International Nuclear Information System (INIS)

Roy, Amitava

2010-01-01

This paper reviews the process of electron emission from metal surface. Although electrons move freely in conductors like metals, they normally do not leave the metal without some manipulation. In fact, heating and bombardment are the two primary ways in which electrons are emitted through the use of a heating element behind the cathode (termed thermionic emission) or as a result of bombardment with a beam of electrons, ions, or metastable atoms (termed secondary emission). Another important emission mechanism called Explosive Electron Emission (EEE) is also often used in various High Voltage Pulse Power Systems to generate very high current (few hundreds of kA) pulsed electron beams. The electron gun is the device in that it shoots off a continuous (or pulsed) stream of electrons. A brief idea about the evolution of the electron gun components and their basis of functioning are also discussed. (author)

Effect of Mycorrhizal Fungus (Glomus spp on Wheat (Triticumaestivum Yield and Yield Components with Regard to Irrigation Water Quality

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S Habibi

2016-02-01

reflect saline stress on mycorrhizal symbiosis than on wheat plants. Results and Discussion The results showed that salinity decreased colonization percentage and grain number per spike but it did not affect yield and yield components significantly. In non- inoculated soil, the formed mycorrhizal symbiosis by indigenous fungi improved colonization percentage, while it did not result in significant differences of the yield and its components. The inoculation with mycorrhiza fungi was successful. Mycorrhizal colonization rates of 15-32% and mycorrhizal dependency rates of 7-13% were observed in the inoculated treatments, and this effect led to significantly higher grain yield, spike number and grain number per plant in compare with control. Furthermore, there was a significant interaction on colonization percentage and whole yield components between AMF inoculation and salinity except for spike number. Spike per plant, grain number per spike and colonization percentage affected by mycorrhizal inoculation in interaction with soil sterilization. Colonization percentage was positively correlated with spike number, grain number per plant and grain yield (significant at α=1%. Conclusions Enhanced yield under all mycorrhizal treatments related to higher grain number per plant, whereas there was no significant difference between these treatments for grain weight. Although the colonization levels of individual mycorrhizal treatments were generally lower, the fostering of grain yield was even strongly more pronounced than with mixed mycorrhizal treat (significant at α=1%. Effects of salinity and soil sterilization varied depending on the species of fungi and water quality. In comparison with other mycorrhizal treatment, G. geosporum showed higher salt tolerant relatively on display of superior colonization percentage and grain number per plant in salinity with tap water; and the colonization percentage by G. mosseae was not affected by soil indigenous fungi. The results showed

Born-Oppenheimer Dynamics, Electronic Friction, and the Inclusion of Electron-Electron Interactions

Science.gov (United States)

Dou, Wenjie; Miao, Gaohan; Subotnik, Joseph E.

2017-07-01

We present a universal expression for the electronic friction as felt by a set of classical nuclear degrees of freedom (DOFs) coupled to a manifold of quantum electronic DOFs; no assumptions are made regarding the nature of the electronic Hamiltonian and electron-electron repulsions are allowed. Our derivation is based on a quantum-classical Liouville equation for the coupled electronic-nuclear motion, followed by an adiabatic approximation whereby electronic transitions are assumed to equilibrate faster than nuclear movement. The resulting form of friction is completely general, but does reduce to previously published expressions for the quadratic Hamiltonian (i.e., Hamiltonians without electronic correlation). At equilibrium, the second fluctuation-dissipation theorem is satisfied and the frictional matrix is symmetric. To demonstrate the importance of electron-electron correlation, we study electronic friction within the Anderson-Holstein model, where a proper treatment of electron-electron interactions shows signatures of a Kondo resonance and a mean-field treatment is completely inadequate.

Ocorrência de Fungos Micorrízicos Arbusculares em resíduo da mineração de bauxita revegetado com espécies arbóreas Arbuscular mycorrhizal fungi occurrence in bauxite mining residue planted to tree species

Directory of Open Access Journals (Sweden)

Ana Lucy Caproni

2007-03-01

Full Text Available Avaliou-se a ocorrência de fungos micorrízicos arbusculares (FMAs em tanques contendo resíduo da mineração de bauxita cultivados com espécies arbóreas inoculadas com Glomus clarum Nicol. & Schenck e Gigaspora margarita Becker & Hall na fase de viveiro. Acacia holosericea A. Cunn. ex G. Don juntamente com Sesbania virgata (Cav. Pers. ou uma mistura de várias espécies foram transplantadas em tanques contendo resíduo de bauxita. Coletaram-se amostras de resíduos em agosto/1998 (estação seca e abril/1999 (estação chuvosa, extraíram e identificaram-se os esporos de FMAs. Determinaram-se a densidade dos esporos de FMAs, a densidade relativa, a freqüência de ocorrência de cada espécie por período de amostragem e o índice de abundância e freqüência (IAF. A densidade dos esporos e a diversidade das espécies de FMAs foram baixas sob ambas as coberturas. Um maior número de esporos de Glomus clarum, e alto IAF, foram detectados no substrato cultivado com Acacia holosericea e Sesbania virgata na época seca. Isto também ocorreu em ambas as áreas na época chuvosa. Não foram encontrados esporos de Gigaspora margarita em ambas as áreas, nas duas épocas. Independentemente da inoculação, verificaram-se esporos de Archeospora leptoticha (Schenck & Smith Morton & Redecker, Entrophospora colombiana Spain & Schenck, Acaulospora mellea Spain & Schenck e Glomus macrocarpum Tulasne & Tulasne em abundância.The establishment of arbuscular mycorrhizal fungi (AMF was evaluated in two areas of bauxite mining residue planted to tree species inoculated with Glomus clarum Nicol. & Schenck and Gigaspora margarita Becker & Hall in the nursery phase. Acacia holosericea A. Cunn. ex G. Don and Sesbania virgata (Cav. Pers. and a mixture of several tree species were transplanted to deposits of containing bauxite mining residue. In August, 1998 (dry season and April, 1999 (rainy season residue samples were collected and AMF spores extracted and

Inoculação de fungos micorrízicos arbusculares em porta-enxerto de pessegueiro cv Okinawa Inoculation of arbuscular mycorrhizal fungi in peach rootstock cv Okinawa

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José Luis da Silva Nunes

2008-12-01

Full Text Available O presente estudo teve por objetivo avaliar a influência da inoculação de fungos micorrízicos arbusculares (FMA sobre o crescimento vegetativo, conteúdo de macronutrientes e de substâncias de reserva de plantas do porta-enxerto de pessegueiro cv Okinawa. O experimento foi realizado em telado, e o delineamento experimental utilizado foi o de blocos casualizados, com 20 plantas por parcela e quatro repetições. Foram testadas três espécies de FMA (Acaulospora sp., Glomus clarum e Glomus etunicatum e um tratamento-testemunha, não-inoculado. A altura, o diâmetro, a área foliar, as biomassas fresca e seca, o conteúdo de macronutrientes e de substâncias de reserva foram avaliados aos 360 dias após a semeadura. Todas as plantas inoculadas com FMA apresentaram maior altura e diâmetro, quando comparadas à testemunha, sendo que Acaulospora sp. promoveu as melhores respostas. Glomus clarum e Glomus etunicatum induziram um crescimento intermediário às plantas. Os FMAs proporcionaram aumento na absorção de nitrogênio, fósforo e potássio, associados à maior altura, diâmetro do colo, área foliar, biomassa fresca e seca da parte aérea e seca das raízes, quando comparadas à testemunha. Todas as plantas inoculadas com FMA tiveram altas taxas de colonização, acima de 90%, sendo que Acaulospora sp. colonizou mais intensamente o sistema radicular das plantas.The present study aimed to evaluate the influence of the arbuscular mycorrhizal fungi (AMF inoculation on the vegetative growth, macronutrients and carbohydrate contents in rootstock plants of peach 'Okinawa'. The experiment was realized at greenhouse conditions and a randomized block design was applied, with 20 plants per plot and four repetitions. Three AMF species (Acaulospora sp., Glomus clarum e Glomus etunicatum and non-inoculated treatment were tested. The stem height and diameter, foliage area, fresh and dry biomass, macronutrients and carbohydrate contents were evaluated

Arbuscular mycorrhizal symbiosis-mediated tomato tolerance to drought.

Science.gov (United States)

Chitarra, Walter; Maserti, Biancaelena; Gambino, Giorgio; Guerrieri, Emilio; Balestrini, Raffaella

2016-07-02

A multidisciplinary approach, involving eco-physiological, morphometric, biochemical and molecular analyses, has been used to study the impact of two different AM fungi, i.e. Funneliformis mosseae and Rhizophagus intraradices, on tomato response to water stress. Overall, results show that AM symbiosis positively affects the tolerance to drought in tomato with a different plant response depending on the involved AM fungal species.

Influencia de diferentes especies de fungo micorrizico arbuscular no desenvolvimento do crisântemo Influence of different species of arbuscular mycorrhizal fungi on chrysanthemum growth

Directory of Open Access Journals (Sweden)

Adriana Parada Dias da Silveira

1996-01-01

Full Text Available Com o objetivo de verificar o desenvolvimento e florescimento do crisântemo (Dendranthema grandiflora na presença de micorriza arbuscular, foi instalado, em casa de vegetação, um experimento, empregando-se os fungos Gigaspora margarita, Glomus leptotichum, Glomus macrocarpum e Scutellospora heterogama. Utilizou-se terra roxa estruturada, da Série Luiz de Queiroz, esterilizada (por autoclavagem e não esterilizada. No florescimento, colheram-se as plantas e determinaram-se a altura, a matéria seca da parte aérea, a matéria fresca da raiz, o teor de P e K na parte aérea, a colonização micorrízica e o número de esporos do fungo micorrízico. O desenvolvimento e o florescimento foram favorecidos pela inoculação de G. leptotichum e G.macrocarpum, quando as plantas foram cultivadas em solo esterilizado, superando o efeito dos fungos micorrízicos nativos. Entretanto, no solo não esterilizado, a inoculação dessas espécies de fungo não promoveu aumento no desenvolvimento da planta.A greenhouse experiment was conducted to verify the effect of arbuscular mycorrhiza on growth and flowering of chrysanthemum. Rooted plants were inoculated with Gigaspora margarita, Glomus leptotichum, Glomus macrocarpum e Scutellospora heterogama or non-inoculated. Plants were grown in a autoclave sterilized, and non-sterilized soil of the type "Terra Roxa Estruturada". At the flowering stage, plants were harvested and measured for plant height, shoot dry matter, root fresh matter, shoot P and K content, mycorrhizal root colonization and number of mycorrhizal fungi spores. Plants colonized with G.leptotichum and G. macrocarpum presented higher growth and flowering than control plants, in sterilized soil, overcoming the effect of native mycorrhizal fungi. However, there was no effect of introduced mycorrhizal fungi on non-sterilized soil.

Impact of an arbuscular mycorrhizal fungus versus a mixed microbial inoculum on the transcriptome reprogramming of grapevine roots.

Science.gov (United States)

Balestrini, Raffaella; Salvioli, Alessandra; Dal Molin, Alessandra; Novero, Mara; Gabelli, Giovanni; Paparelli, Eleonora; Marroni, Fabio; Bonfante, Paola

2017-07-01

Grapevine, cultivated for both fruit and beverage production, represents one of the most economically important fruit crops worldwide. With the aim of better understanding how grape roots respond to beneficial microbes, a transcriptome sequencing experiment has been performed to evaluate the impact of a single arbuscular mycorrhizal (AM) fungal species (Funneliformis mosseae) versus a mixed inoculum containing a bacterial and fungal consortium, including different AM species, on Richter 110 rootstock. Results showed that the impact of a single AM fungus and of a complex microbial inoculum on the grapevine transcriptome differed. After 3 months, roots exclusively were colonized after the F. mosseae treatment and several AM marker genes were found to be upregulated. The mixed inoculum led only to traces of colonization by AM fungi, but elicited an important transcriptional regulation. Additionally, the expression of genes belonging to categories such as nutrient transport, transcription factors, and cell wall-related genes was significantly altered in both treatments, but the exact genes affected differed in the two conditions. These findings advance our understanding about the impact of soil beneficial microbes on the root system of a woody plant, also offering the basis for novel approaches in grapevine cultivation.

Effective electron-electron and electron-phonon interactions in the Hubbard-Holstein model

International Nuclear Information System (INIS)

Aprea, G.; Di Castro, C.; Grilli, M. . E-mail marco.grilli@roma1.infn.it; Lorenzana, J.

2006-01-01

We investigate the interplay between the electron-electron and the electron-phonon interaction in the Hubbard-Holstein model. We implement the flow-equation method to investigate within this model the effect of correlation on the electron-phonon effective coupling and, conversely, the effect of phonons in the effective electron-electron interaction. Using this technique we obtain analytical momentum-dependent expressions for the effective couplings and we study their behavior for different physical regimes. In agreement with other works on this subject, we find that the electron-electron attraction mediated by phonons in the presence of Hubbard repulsion is peaked at low transferred momenta. The role of the characteristic energies involved is also analyzed

Electron-electron coincidence spectroscopies at surfaces

International Nuclear Information System (INIS)

Stefani, G.; Iacobucci, S.; Ruocco, A.; Gotter, R.

2002-01-01

In the past 20 years, a steadily increasing number of electron-electron coincidence experiments on atoms and molecules have contributed to a deeper understanding of electron-electron correlation effects. In more recent years this technique has been extended to the study of solid surfaces. This class of one photon IN two electrons OUT experiments will be discussed with an emphasis on grazing incidence geometry, that is expected to be particularly suited for studying surfaces. The crucial question of which is the dominant mechanism that leads to ejection of pairs of electron from the surface will be addressed. It will be shown that, depending on the kinematics chosen, the correlated behaviour of the pairs of electrons detected might be singled out from independent particle one

Electron distribution function in electron-beam-excited plasmas

International Nuclear Information System (INIS)

Brau, C.A.

1976-01-01

In monatomic plasmas excited by high-intensity relativistic electron beams, the electron secondary distribution function is dominated by elastic electron-electron collisions at low electron energies and by inelastic electron-atom collisions at high electron energies (above the excitation threshold). Under these conditions, the total rate of excitation by inelastic collisions is limited by the rate at which electron-electron collisions relax the distribution function in the neighborhood of the excitation threshold. To describe this effect quantitatively, an approximate analytic solution of the electron Boltzmann equation is obtained, including both electron-electron and inelastic collisions. The result provides a simple formula for the total rate of excitation

Hard electronics; Hard electronics

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-03-01

Hard material technologies were surveyed to establish the hard electronic technology which offers superior characteristics under hard operational or environmental conditions as compared with conventional Si devices. The following technologies were separately surveyed: (1) The device and integration technologies of wide gap hard semiconductors such as SiC, diamond and nitride, (2) The technology of hard semiconductor devices for vacuum micro- electronics technology, and (3) The technology of hard new material devices for oxides. The formation technology of oxide thin films made remarkable progress after discovery of oxide superconductor materials, resulting in development of an atomic layer growth method and mist deposition method. This leading research is expected to solve such issues difficult to be easily realized by current Si technology as high-power, high-frequency and low-loss devices in power electronics, high temperature-proof and radiation-proof devices in ultimate electronics, and high-speed and dense- integrated devices in information electronics. 432 refs., 136 figs., 15 tabs.

Electron radiography

Science.gov (United States)

Merrill, Frank E.; Morris, Christopher

2005-05-17

A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.

Electron transfer from electronic excited states to sub-vacuum electron traps in amorphous ice

International Nuclear Information System (INIS)

Vichnevetski, E.; Bass, A.D.; Sanche, L.

2000-01-01

We investigate the electron stimulated yield of electronically excited argon atoms (Ar * ) from monolayer quantities of Ar deposited onto thin films of amorphous ice. Two peaks of narrow width ( - electron-exciton complex into exciton states, by the transfer of an electron into a sub-vacuum electron state within the ice film. However, the 10.7 eV feature is shifted to lower energy since electron attachment to Ar occurs within small pores of amorphous ice. In this case, the excess electron is transferred into an electron trap below the conduction band of the ice layer

Production and infectivity of inoculum of arbuscular mycorrhizal fungi multiplied in a substrate supplemented with Tris-HCl buffer Produção e infectividade de inóculo de fungos micorrízicos arbusculares multiplicados em substrato suplementado com tampão Tris-HCl

Directory of Open Access Journals (Sweden)

Fábio Sérgio Barbosa da Silva

2007-12-01

Full Text Available The effect of adding Tris-HCl buffer on production and infectivity of AMF inoculum was investigated. Sporulation of Glomus etunicatum, Acaulospora longula and Gigaspora albida was improved in solution with buffer. The infectivity of G. etunicatum increased after storage, what suggests that the inoculum of this isolate is benefited by storage.O efeito da adição do tampão Tris-HCl na produção e infectividade de inóculo foi investigado. A esporulação de Glomus etunicatum, Acaulospora longula e Gigaspora albida foi incrementada utilizando solução com tampão. A infectividade de G. etunicatum aumentou após estocagem, sugerindo que o inóculo deste isolado é beneficiado pelo armazenamento.

Distribution of dominant arbuscular mycorrhizal fungi among five plant species in undisturbed vegetation of a coastal grassland

DEFF Research Database (Denmark)

Holtgrewe-Stukenbrock, Eva; Rosendahl, Søren

2005-01-01

Most plant species in mixed grassland vegetation are colonized by arbuscular mycorrhizal (AM) fungi. Previous studies have reported differences in host preferences among AM fungi, although the fungi are known to lack host specificity. In the present study, the distribution of phylogenetic groups...... of AM fungi belonging to a clade of Glomus species was studied in five plant species from a coastal grassland in Denmark. The occurrence of the fungi was determined by PCR analyses of fungal large subunit ribosomal DNA sequences amplified from root fragments using a specific primer set. The results...... showed that the dominant Glomus species were able to colonize all the studied plant species, supporting the view that the AM fungi represent a large underground interconnecting mycelial network....

Monte Carlo study of electron relaxation in graphene with spin polarized, degenerate electron gas in presence of electron-electron scattering

Science.gov (United States)

Borowik, Piotr; Thobel, Jean-Luc; Adamowicz, Leszek

2017-12-01

The Monte Carlo simulation method is applied to study the relaxation of excited electrons in monolayer graphene. The presence of spin polarized background electrons population, with density corresponding to highly degenerate conditions is assumed. Formulas of electron-electron scattering rates, which properly account for electrons presence in two energetically degenerate, inequivalent valleys in this material are presented. The electron relaxation process can be divided into two phases: thermalization and cooling, which can be clearly distinguished when examining the standard deviation of electron energy distribution. The influence of the exchange effect in interactions between electrons with parallel spins is shown to be important only in transient conditions, especially during the thermalization phase.

Electron attachment cross sections obtained from electron attachment spectroscopy

International Nuclear Information System (INIS)

Popp, P.; Baumbach, J.I.; Leonhardt, J.W.; Mothes, S.

1988-01-01

Electron capture detectors have a high sensitivity for substances with high thermal electron attachment cross sections. The electron attachment spectroscopy makes it possible to change the mean electron energy in such a way that the maximum for dissociative electron attachment is reached. Thus, best operation modes of the detection system as well as significant dependencies of electron attachment coefficients are available. Cross sections for electron attachment as a function of the electron energy are obtained with the knowledge of electron energy distribution functions from Boltzmann equation analysis by a special computer code. A disadvantage of this electron attachment spectroscopy is the superposition of space charge effects due to the decrease of the electron drift velocity with increasing mean electron energy. These influences are discussed. (author)

Electron beam effects in auger electron spectroscopy and scanning electron microscopy

International Nuclear Information System (INIS)

Fontaine, J.M.; Duraud, J.P.; Le Gressus, C.

1979-01-01

Electron beam effects on Si(100) and 5% Fe/Cr alloy samples have been studied by measurements of the secondary electron yield delta, determination of the surface composition by Auger electron spectroscopy and imaging with scanning electron microscopy. Variations of delta as a function of the accelerating voltage Esub(p) (0.5 -9 Torr has no effect on technological samples covered with their reaction layers; the sensitivities to the beam depend rather on the earlier mechanical, thermal and chemical treatment of the surfaces. (author)

The effect of electron-electron interaction induced dephasing on electronic transport in graphene nanoribbons

Energy Technology Data Exchange (ETDEWEB)

Kahnoj, Sina Soleimani; Touski, Shoeib Babaee [School of Electrical and Computer Engineering, University of Tehran, P.O. Box 14395-515, Tehran (Iran, Islamic Republic of); Pourfath, Mahdi, E-mail: pourfath@ut.ac.ir, E-mail: pourfath@iue.tuwien.ac.at [School of Electrical and Computer Engineering, University of Tehran, P.O. Box 14395-515, Tehran (Iran, Islamic Republic of); Institute for Microelectronics, TU Wien, Gusshausstrasse 27–29/E360, 1040 Vienna (Austria)

2014-09-08

The effect of dephasing induced by electron-electron interaction on electronic transport in graphene nanoribbons is theoretically investigated. In the presence of disorder in graphene nanoribbons, wavefunction of electrons can set up standing waves along the channel and the conductance exponentially decreases with the ribbon's length. Employing the non-equilibrium Green's function formalism along with an accurate model for describing the dephasing induced by electron-electron interaction, we show that this kind of interaction prevents localization and transport of electrons remains in the diffusive regime where the conductance is inversely proportional to the ribbon's length.

Electron Beam Generation in Tevatron Electron Lenses

International Nuclear Information System (INIS)

Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.

2006-01-01

New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

Electron beam generation in Tevatron electron lenses

International Nuclear Information System (INIS)

Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.

2006-01-01

New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices

Electronic technology

International Nuclear Information System (INIS)

Kim, Jin Su

2010-07-01

This book is composed of five chapters, which introduces electronic technology about understanding of electronic, electronic component, radio, electronic application, communication technology, semiconductor on its basic, free electron and hole, intrinsic semiconductor and semiconductor element, Diode such as PN junction diode, characteristic of junction diode, rectifier circuit and smoothing circuit, transistor on structure of transistor, characteristic of transistor and common emitter circuit, electronic application about electronic equipment, communication technology and education, robot technology and high electronic technology.

Application of arbuscular mycorrhizal fungi with Pseudomonas aeruginosa UPMP3 reduces the development of Ganoderma basal stem rot disease in oil palm seedlings.

Science.gov (United States)

Sundram, Shamala; Meon, Sariah; Seman, Idris Abu; Othman, Radziah

2015-07-01

The effect of arbuscular mycorrhizal fungi (AMF) in combination with endophytic bacteria (EB) in reducing development of basal stem rot (BSR) disease in oil palm (Elaeis guineensis) was investigated. BSR caused by Ganoderma boninense leads to devastating economic loss and the oil palm industry is struggling to control the disease. The application of two AMF with two EB as biocontrol agents was assessed in the nursery and subsequently, repeated in the field using bait seedlings. Seedlings pre-inoculated with a combination of Glomus intraradices UT126, Glomus clarum BR152B and Pseudomonas aeruginosa UPMP3 significantly reduced disease development measured as the area under disease progression curve (AUDPC) and the epidemic rate (R L) of disease in the nursery. A 20-month field trial using similar treatments evaluated disease development in bait seedlings based on the rotting area/advancement assessed in cross-sections of the seedling base. Data show that application of Glomus intraradices UT126 singly reduced disease development of BSR, but that combination of the two AMF with P. aeruginosa UPMP3 significantly improved biocontrol efficacy in both nursery and fields reducing BSR disease to 57 and 80%, respectively. The successful use of bait seedlings in the natural environment to study BSR development represents a promising alternative to nursery trial testing in the field with shorter temporal assessment.

PERTUMBUHAN TANAMAN SENGON (PARASERIANTHES FALCATARIA L. TERINFEKSI MIKORIZA PADA LAHAN TERCEMAR Pb.

Directory of Open Access Journals (Sweden)

Triono Bagus Saputro

2016-11-01

Full Text Available Paraserianthes falcataria plant is well known to be capable to make an excellent association and symbiosis with mycorrhizae. Mycorrhizae can improve the plant's ability to survive in heavy metal contaminated land, one of which is Pb (lead. Pb is the main heavy metal pollutants in all environments. This aims of this research were to determine the accumulation of Pb on sengon plant roots and its growth in Pb contaminated media. This research uses a completely randomized design. Pb(NO32 were given at a dose of 833 mg/kg and the concentration of mycorrhizal inoculation of Glomus sp. used were 25, 50 and 75 grams of mycorrhizae. The measured parameters were plant height, root length, plant dry weight, accumulation of Pb in roots, chlorophyll and protein profile test. The results showed that 75 grams of mycorrhizal Glomus sp. were the highest on several parameters including plant height, dry weight, root length. The chlorophyll content were grown on media containing Pb with each value of 77.5 cm; 17.86 grams; 31.5 cm; 8.99 g/ml. A dose of 75 grams of Glomus sp. also increased the absorption and accumulation of Pb in the roots with 3.60 ppm. while the protein electrophoresis show the specific band in P. falcataria that exposed to Pb with molecular weight 53.67 kDa.

The Electron

Energy Technology Data Exchange (ETDEWEB)

Thomson, George

1972-01-01

Electrons are elementary particles of atoms that revolve around and outside the nucleus and have a negative charge. This booklet discusses how electrons relate to electricity, some applications of electrons, electrons as waves, electrons in atoms and solids, the electron microscope, among other things.

Determination of the electron-electron collisional frequency by means of plasma electron spectroscopy

International Nuclear Information System (INIS)

Kolokolov, N.B.; Kudryavtsev, A.A.; Romanenko, V.A.

1989-01-01

Methods of controlling fast part of electron distribution function (DF) in nonlocal regime of current-free plasma are suggested and realized. Artificially created step in DF fast part has a simple link with frequencies of electron-electron and elastic electron-atom collisions that may be defined in the corresponding experiments

Electron beam-plasma interaction and electron-acoustic solitary waves in a plasma with suprathermal electrons

Science.gov (United States)

Danehkar, A.

2018-06-01

Suprathermal electrons and inertial drifting electrons, so called electron beam, are crucial to the nonlinear dynamics of electrostatic solitary waves observed in several astrophysical plasmas. In this paper, the propagation of electron-acoustic solitary waves (EAWs) is investigated in a collisionless, unmagnetized plasma consisting of cool inertial background electrons, hot suprathermal electrons (modeled by a κ-type distribution), and stationary ions. The plasma is penetrated by a cool electron beam component. A linear dispersion relation is derived to describe small-amplitude wave structures that shows a weak dependence of the phase speed on the electron beam velocity and density. A (Sagdeev-type) pseudopotential approach is employed to obtain the existence domain of large-amplitude solitary waves, and investigate how their nonlinear structures depend on the kinematic and physical properties of the electron beam and the suprathermality (described by κ) of the hot electrons. The results indicate that the electron beam can largely alter the EAWs, but can only produce negative polarity solitary waves in this model. While the electron beam co-propagates with the solitary waves, the soliton existence domain (Mach number range) becomes narrower (nearly down to nil) with increasing the beam speed and the beam-to-hot electron temperature ratio, and decreasing the beam-to-cool electron density ratio in high suprathermality (low κ). It is found that the electric potential amplitude largely declines with increasing the beam speed and the beam-to-cool electron density ratio for co-propagating solitary waves, but is slightly decreased by raising the beam-to-hot electron temperature ratio.

ORGANIC COMPOST AND MYCORRHIZAL INOCULATION ON PHYSIC NUT SEEDLINGS COMPOSTO ORGÂNICO E INOCULAÇÃO MICORRÍZICA NA PRODUÇÃO DE MUDAS DE PINHÃO MANSO

Directory of Open Access Journals (Sweden)

Nanci Cappi

2010-08-01

Full Text Available

Physic nut species has shown great potential for biofuel production. This study aimed to evaluate the effect of inoculation with the arbuscular mycorrhizal fungus Glomus clarum and the application of organic compost on the growth and phosphorus (P and nitrogen (N absorption, in physic nut seedlings. A randomized experimental blocks design, in a 5x2 factorial scheme, was used, with the evaluation of organic compost levels (0 t ha^-1, 15 t ha^-1, 30 t ha^-1, 60 t ha^-1, and 120 t ha^-1 and presence or absence of Glomus clarum, with four replications. Physic nut seedlings inoculated with Glomus clarum presented, at levels of 15 t ha^-1 of organic compost, the lowest height (20%, 120 days after sowing. However, the basal diameter increased, at levels of 30 t ha^-1 (21% and 120 t ha^-1 (33% of organic compost, 60 days after sowing. Only in the

Role of Arbuscular Mycorrhizal Fungi on Iris

Directory of Open Access Journals (Sweden)

CHEN Yuan

2014-06-01

Full Text Available For efficiency using the amphibious plant iris to restore polluted water, the promoting effect of different arbuscular mycorrhiza fungi（AMFon iris was investigated, by monitoring the plant growth index, the physicochemical properties of the soil and the plant photosynthesis indexes. The result showed that the promoting effects of the AMF on the aboveground part and the underground part of the iris were based on different mechanism. For the underground part of the iris, the AMF stimulated its growth through the nutrient enrichment which was performed by the enormous hypha network. The nitrogen absorbing rate of the G. mosseae and the G. intraradices infected iris increased about 71.75% and 42.55%, and the phosphorous absorbing rate increased 8.36% and 9.5% separately. For the aboveground part of the iris, the AMF strengthened the conductance of the leaves’ stomas to control the balance between the net photosynthesis rate and the transpiration rate, so that the utilization rate of water resources was optimized, the metabolic rate was accelerated and the growth of the plant was promoted eventually. In this study, the promoting effect of the G. mosseae on the photosynthesis rate of the iris was significantly better than that of the G. intraradices(P<0.05.

Caracterização fenotípica e molecular de esporos de fungos micorrízicos arbusculares mantidos em banco de germoplasma Phenotypic and molecular characterization of arbuscular mycorrhizal fungal spores from cultures maintained in germplasm collection

Directory of Open Access Journals (Sweden)

Cândido Barreto de Novais

2010-08-01

Full Text Available O objetivo deste trabalho foi caracterizar fenotípica e genotipicamente isolados de espécies de fungos micorrízicos arbusculares (FMA mantidos em cultura pura e avaliar a aplicabilidade da técnica PCR-DGGE desenvolvida para Gigaspora, na identificação molecular de espécies de FMA pertencentes a outros gêneros. A caracterização fenotípica das espécies foi realizada de acordo com critérios morfológicos, descritos pela taxonomia, e com uso de descrições originais das espécies presentes na literatura especializada. A análise genotípica foi feita com base na discriminação específica da região V9 do 18S rDNA, que permitiu a diferenciação das espécies e não revelou qualquer diferença entre os isolados geográficos de Glomus clarum, e entre os de Glomus etunicatum. Isto indica a aplicabilidade da técnica para a avaliação da pureza genética e discriminação de espécies de FMA.The objective of this work was to characterize phenotypically and genotypically isolates of arbuscular mycorrhizal fungi (AMF maintained in pure culture and to evaluate the applicability of PCR-DGGE analysis, developed for Gigaspora, for molecular identification of AMF species belonging to other genres. The species phenotypic characterization was done according to morphological criteria, as described by taxonomy, and according to original descriptions of species published in the specialized literature. The genotypic analysis was made through specific discrimination of the V9 region in the 18S rDNA, which allowed the distinction of species and showed no difference among geographical isolates of Glomus clarum, and among those of Glomus etunicatum. This indicates the applicability of this technique for assessment of genetic purity and discrimination of AMF species.

Crescimento de mudas micropropagadas de bananeira micorrizadas em diferentes recipientes Growth of mycorrhizal micropropagated banana plantlets in different recipients

Directory of Open Access Journals (Sweden)

Patrícia Lopes Leal

2005-04-01

Full Text Available Realizou-se um experimento em casa de vegetação, com o objetivo de avaliar a utilização de diferentes recipientes e a eficiência da inoculação com fungo micorrízico arbuscular (FMA, Glomus clarum, no crescimento de mudas micropropagadas de bananeira. O delineamento experimental foi o de blocos casualizados, no esquema fatorial 2x2, sendo 2 tratamentos microbiológicos: Glomus clarum e controle; e 2 recipientes: blocos prensados e tubetes, com 6 repetições. O substrato utilizado para a confecção dos blocos e para o enchimento dos tubetes foi constituído por uma mistura de materiais orgânicos (bagaço de cana + torta de filtro de usina açucareira e vermiculita. Mudas de bananeira produzidas em blocos prensados e inoculadas com o FMA apresentaram melhores resultados quando comparadas com as produzidas nos tubetes, com incrementos na altura, na produção de matéria seca da parte aérea e no acúmulo de N, P e K de 90%, 829%, 2774%, 249% e 403%, respectivamente.An experiment under greenhouse was carried out in order to evaluate different recipients and the inoculation with arbuscular mycorrhizal fungus (AMF, Glomus clarum, on the growth of micropropagated banana plantlets. A random block design in a factorial scheme 2x2 (two microbiological treatments: Glomus clarum and control; two types of recipients: pressed blocks and plastic tubes, with six repetitions, was used. The substrate utilized to construct the pressed blocks and to fill the tubes was constituted by a mixture of organic residue (sugarcane bagasse and filter cake and vermiculite. Banana plantlets produced in pressed blocks and inoculated with AMF let to better results than their counterparts grown in tubes, increasing the height, shoot dry weight, contents of N, P and K in 90%, 829%, 2774%, 249% and 403%, respectively.

The potential of endomycorrhizal fungi in controlling tomato bacterial ...

African Journals Online (AJOL)

user

2012-08-21

Aug 21, 2012 ... The impact of colonization by three mycorrhizal fungi on tomato bacterial wilt caused by Ralstonia ... Three species of arbuscular mycorrhizal fungal (AMF) were tested. (Glomus ...... management of fruits and vegetables. Vol.

Selective accumulation of biotin in arterial chemoreceptors: requirement for carotid body exocytotic dopamine secretion.

Science.gov (United States)

Ortega-Sáenz, Patricia; Macías, David; Levitsky, Konstantin L; Rodríguez-Gómez, José A; González-Rodríguez, Patricia; Bonilla-Henao, Victoria; Arias-Mayenco, Ignacio; López-Barneo, José

2016-12-15

Biotin, a vitamin whose main role is as a coenzyme for carboxylases, accumulates at unusually large amounts within cells of the carotid body (CB). In biotin-deficient rats biotin rapidly disappears from the blood; however, it remains at relatively high levels in CB glomus cells. The CB contains high levels of mRNA for SLC5a6, a biotin transporter, and SLC19a3, a thiamine transporter regulated by biotin. Animals with biotin deficiency exhibit pronounced metabolic lactic acidosis. Remarkably, glomus cells from these animals have normal electrical and neurochemical properties. However, they show a marked decrease in the size of quantal dopaminergic secretory events. Inhibitors of the vesicular monoamine transporter 2 (VMAT2) mimic the effect of biotin deficiency. In biotin-deficient animals, VMAT2 protein expression decreases in parallel with biotin depletion in CB cells. These data suggest that dopamine transport and/or storage in small secretory granules in glomus cells depend on biotin. Biotin is a water-soluble vitamin required for the function of carboxylases as well as for the regulation of gene expression. Here, we report that biotin accumulates in unusually large amounts in cells of arterial chemoreceptors, carotid body (CB) and adrenal medulla (AM). We show in a biotin-deficient rat model that the vitamin rapidly disappears from the blood and other tissues (including the AM), while remaining at relatively high levels in the CB. We have also observed that, in comparison with other peripheral neural tissues, CB cells contain high levels of SLC5a6, a biotin transporter, and SLC19a3, a thiamine transporter regulated by biotin. Biotin-deficient rats show a syndrome characterized by marked weight loss, metabolic lactic acidosis, aciduria and accelerated breathing with normal responsiveness to hypoxia. Remarkably, CB cells from biotin-deficient animals have normal electrophysiological and neurochemical (ATP levels and catecholamine synthesis) properties; however

Fungos micorrízicos arbusculares em estéril revegetado com Acacia mangium, após mineração de bauxita Colonization of arbuscular mycorrhizae fungi in substrate, after bauxite mining, vegetated with Acacia mangium

Directory of Open Access Journals (Sweden)

Ana Lucy Caproni

2005-06-01

Full Text Available O objetivo deste trabalho foi avaliar a composição das comunidades de FMAs em áreas revegetadas com Acacia mangium após a mineração de bauxita na região de Porto Trombetas, PA. Foram coletadas amostras de solo compostas nos períodos seco e chuvoso, em áreas revegetadas com Acacia mangium, que receberam inóculos de Glomus clarum e Gigaspora margarita, com 1 e 5 anos de idade. Os solos foram revegetados sem a reposição do horizonte superficial orgânico. Os esporos dos fungos micorrízicos arbusculares (FMAs foram extraídos e identificados através de suas características morfológicas. Analisou-se a densidade de esporos e de espécies em cada amostra, a densidade relativa e a freqüência de ocorrência de cada espécie por período de amostragem, além do índice de abundância e freqüência (IAF. Sob o plantio de mudas de A. mangium, a densidade de esporos de FMAs foi elevada e aumentou com a idade, enquanto o número de espécies não variou. Glomus clarum produz alta densidade de esporos na fase inicial do plantio e declina com o tempo, e Gigaspora margarita não esporula nas condições edafoclimáticas locais. A maioria das espécies de FMA não apresenta o mesmo padrão de esporulação nos períodos seco e chuvoso.The objective of this work was to monitor the establishment of Gigaspora margarita and Glomus clarum in reclaimed areas after the bauxite mining in Porto Trombetas, PA, Brazil. Soil samples were collected during the dry and rainy periods under one and five-year-old Acacia mangium trees grown from seedlings that had been inoculated with Glomus clarum and Gigaspora margarita. The exposed subsoil was managed without replacing the organic soil layer. FMA spores were extracted and identified through their morphologic characteristics. Spore density and frequency of each species were determined in each sampling The index of abundance and frequency (IAF were estimated for all samples. Under A. mangium the arbuscular

Fungos micorrízicos arbusculares no crescimento e nutrição de mudas de jenipapeiro Arbuscular mycorrhizal fungi in the growth and nutrition of jenipapo fruit tree seedlings

Directory of Open Access Journals (Sweden)

Ana Cristina Fermino Soares

2012-03-01

Full Text Available Alguns trabalhos têm demonstrado que a inoculação de fungos micorrízicos arbusculares (FMA na produção de mudas apresenta grande potencial para o desenvolvimento de um cultivo racional e eficiente de mudas de fruteiras. O objetivo neste trabalho foi avaliar a inoculação de fungos micorrízicos arbusculares no crescimento e nutrição de mudas de jenipapeiro (Genipa americana L.. O experimento foi conduzido em blocos casualizados, avaliando-se seis espécies fúngicas: Glomus clarum, Glomus etunicatum, Glomus manihots, Gigaspora albida, Acaulospora scrobiculata e Scutellospora heterogama, com dez repetições. As espécies A. scrobiculata, G. clarum e G. etunicatum colonizaram mais intensamente o sistema radicular e promoveram melhor desenvolvimento das mudas de jenipapeiro quando comparados a G. manihots e G. albida. O fungo G. etunicatum destacou-se, promovendo incrementos na altura (44,4%; no diâmetro do caule (63,6%; na produção de biomassa seca na parte aérea (288,8%, nas raízes (248,7% e na área foliar (315,7% em comparação às mudas controle. Com exceção de Mn e Fe, mudas inoculadas apresentaram teores de nutrientes superior às mudas controle. As mudas que receberam inóculo de S. heterogama apresentaram crescimento e teor de nutrientes similares aos das mudas controle. A colonização micorrízica correlacionou-se positivamente com os teores de N, P, K, Mg e Cu e negativamente com os teores de Fe e Mn nas folhas das mudas de jenipapeiro. O jenipapeiro é uma planta responsiva aos FMA e a inoculação beneficiou o crescimento e a nutrição das mudas.Some studies have shown that inoculation with arbuscular mycorrhizal fungi (AMF in seedling production has great potential for developing a rational and efficient cultivation of fruit tree seedlings. The objective of this study was to evaluate the effect of inoculation of arbuscular mycorrhizal fungi on growth and nutrition of seedlings of genipap (Genipa americana L.. The

Electronic Government and Electronic Participation

NARCIS (Netherlands)

Tambouris, E; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K; Gascó, M; Klievink, A.J.; Lindgren, I; Milano, M; Panagiotopoulos, P; Pardo, T.A.; Parycek, P; Sæbø, Ø

2016-01-01

Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies.This book presents papers from the 14th International Federation for Information

Electronic Government and Electronic Participation

NARCIS (Netherlands)

Tambouris, E.; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K.; Gascó, M.; Klievink, A.J.; Lindgren, I.; Milano, M.; Panagiotopoulos, P.; Pardo, T.A.; Parycek, P.; Sæbø, O.

2015-01-01

Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies. This book presents papers from the 14th International Federation for Information

Electron detector

International Nuclear Information System (INIS)

Hashimoto, H.; Mogami, A.

1975-01-01

A device for measuring electron densities at a given energy level in an electron beam or the like having strong background noise, for example, in the detection of Auger electric energy spectrums is described. An electron analyzer passes electrons at the given energy level and at the same time electrons of at least one adjacent energy level. Detecting means associated therewith produce signals indicative of the densities of the electrons at each energy level and combine these signals to produce a signal indicative of the density of the electrons of the given energy level absent background noise

Electron-electron interactions in artificial graphene

Science.gov (United States)

Rasanen, Esa

2013-03-01

Recent advances in the creation and modulation of graphenelike systems are introducing a science of ``designer Dirac materials.'' In its original definition, artificial graphene is a man-made nanostructure that consists of identical potential wells (quantum dots) arranged in an adjustable honeycomb lattice in the two-dimensional electron gas. As our ability to control the quality of artificial graphene samples improves, so grows the need for an accurate theory of its electronic properties, including the effects of electron-electron interactions. Here we determine those effects on the band structure and on the emergence of Dirac points, and discuss future investigations and challenges in this field.

Decal electronics for printed high performance cmos electronic systems

KAUST Repository

Hussain, Muhammad Mustafa

2017-11-23

High performance complementary metal oxide semiconductor (CMOS) electronics are critical for any full-fledged electronic system. However, state-of-the-art CMOS electronics are rigid and bulky making them unusable for flexible electronic applications. While there exist bulk material reduction methods to flex them, such thinned CMOS electronics are fragile and vulnerable to handling for high throughput manufacturing. Here, we show a fusion of a CMOS technology compatible fabrication process for flexible CMOS electronics, with inkjet and conductive cellulose based interconnects, followed by additive manufacturing (i.e. 3D printing based packaging) and finally roll-to-roll printing of packaged decal electronics (thin film transistors based circuit components and sensors) focusing on printed high performance flexible electronic systems. This work provides the most pragmatic route for packaged flexible electronic systems for wide ranging applications.

Electron-beam-induced-current and active secondary-electron voltage-contrast with aberration-corrected electron probes

Energy Technology Data Exchange (ETDEWEB)

Han, Myung-Geun, E-mail: mghan@bnl.gov [Condensed Matter Physics & Materials Science, Brookhaven National Laboratory, Upton, NY 11973 (United States); Garlow, Joseph A. [Condensed Matter Physics & Materials Science, Brookhaven National Laboratory, Upton, NY 11973 (United States); Materials Science and Engineering Department, Stony Brook University, Stony Brook, NY 11794 (United States); Marshall, Matthew S.J.; Tiano, Amanda L. [Department of Chemistry, Stony Brook University, Stony Brook, NY 11974 (United States); Wong, Stanislaus S. [Condensed Matter Physics & Materials Science, Brookhaven National Laboratory, Upton, NY 11973 (United States); Department of Chemistry, Stony Brook University, Stony Brook, NY 11974 (United States); Cheong, Sang-Wook [Department of Physics and Astronomy, Rutgers Center for Emergent Materials, Rutgers University, Piscataway, NJ 08854 (United States); Walker, Frederick J.; Ahn, Charles H. [Department of Applied Physics and Center for Research on Interface Structures and Phenomena, Yale University, New Haven, CT 06520 (United States); Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT 06520 (United States); Zhu, Yimei [Condensed Matter Physics & Materials Science, Brookhaven National Laboratory, Upton, NY 11973 (United States)

2017-05-15

Highlights: • Electron-beam-induced-current (EBIC) and active secondary-electron voltage-contrast (SE-VC) are demonstrated in STEM mode combined with in situ electrical biasing in a TEM. • Electrostatic potential maps in ferroelectric thin films, multiferroic nanowires, and single crystals obtained by off-axis electron holography were compared with EBIC and SE-VC data. • Simultaneous EBIC and active SE-VC performed with atomic resolution STEM are demonstrated. - Abstract: The ability to map out electrostatic potentials in materials is critical for the development and the design of nanoscale electronic and spintronic devices in modern industry. Electron holography has been an important tool for revealing electric and magnetic field distributions in microelectronics and magnetic-based memory devices, however, its utility is hindered by several practical constraints, such as charging artifacts and limitations in sensitivity and in field of view. In this article, we report electron-beam-induced-current (EBIC) and secondary-electron voltage-contrast (SE-VC) with an aberration-corrected electron probe in a transmission electron microscope (TEM), as complementary techniques to electron holography, to measure electric fields and surface potentials, respectively. These two techniques were applied to ferroelectric thin films, multiferroic nanowires, and single crystals. Electrostatic potential maps obtained by off-axis electron holography were compared with EBIC and SE-VC to show that these techniques can be used as a complementary approach to validate quantitative results obtained from electron holography analysis.

Electronic Commerce and Electronic Business

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

This special issue is motivated by the recent upsurge of research activity in the areas of electronic commerce and electronic business both in India and all over the world. The current ... Monte Carlo methods for pricing financial options are then.

Electron optical characteristics of a concave electrostatic electron mirror for a scanning electron microscope

International Nuclear Information System (INIS)

Hamarat, R.T.; Witzani, J.; Hoerl, E.M.

1984-08-01

Numerical computer calculations are used to explore the design characteristics of a concave electrostatic electron mirror for a mirror attachment for a conventional scanning electron microscope or an instrument designed totally as a scanning electron mirror microscope. The electron paths of a number of set-ups are calculated and drawn graphically in order to find the optimum shape and dimensions of the mirror geometry. This optimum configuration turns out to be the transition configuration between two cases of electron path deflection, towards the optical axis of the system and away from it. (Author)

Electronic processes in organic electronics bridging nanostructure, electronic states and device properties

CERN Document Server

Kudo, Kazuhiro; Nakayama, Takashi; Ueno, Nobuo

2015-01-01

The book covers a variety of studies of organic semiconductors, from fundamental electronic states to device applications, including theoretical studies. Furthermore, innovative experimental techniques, e.g., ultrahigh sensitivity photoelectron spectroscopy, photoelectron yield spectroscopy, spin-resolved scanning tunneling microscopy (STM), and a material processing method with optical-vortex and polarization-vortex lasers, are introduced. As this book is intended to serve as a textbook for a graduate level course or as reference material for researchers in organic electronics and nanoscience from electronic states, fundamental science that is necessary to understand the research is described. It does not duplicate the books already written on organic electronics, but focuses mainly on electronic properties that arise from the nature of organic semiconductors (molecular solids). The new experimental methods introduced in this book are applicable to various materials (e.g., metals, inorganic and organic mater...

Chapter 4: Hongos Hipogeos de Tamulipas, Mexico

Science.gov (United States)

Gonzalo Guevara-Guerrero; Efren Cazares-Gonzalez; Gregory Bonito; Rosanne A. Healy; Benjamin Stielow; Jesus Garcia; Fortunato Garza-Ocanas; Michael Castellano; James Trappe

2014-01-01

Twenty genera of hypogeous fungi or truffles are reported and illustrated from the State of Tamaulipas. The truffles belong to the following phyla: Glomeromycota (Glomus); Zygomycota (Endogone); hypogeous Ascomycota (Elaphomyces, Genabea, Genea, Hydnobolites, Pachyphloeus, Tuber); and Basidiomycota (...

Decal electronics for printed high performance cmos electronic systems

KAUST Repository

Hussain, Muhammad Mustafa; Sevilla, Galo Torres; Cordero, Marlon Diaz; Kutbee, Arwa T.

2017-01-01

High performance complementary metal oxide semiconductor (CMOS) electronics are critical for any full-fledged electronic system. However, state-of-the-art CMOS electronics are rigid and bulky making them unusable for flexible electronic applications

Precession mechanism of spin relaxation at frequent electron-electron collisions

CERN Document Server

Glazov, M M

2002-01-01

It is shown that the spin relaxation mechanism in the two-dimensional electron gas, is controlled not only through the electron pulse relaxation processes, determining the mobility, but through the electron-electron collisions as well. It is decided to use the kinetic equation, describing the electron spin mixing in the k-space, for determining the spin relaxation time tau sub s at frequent electron-electron collisions. The tau sub s time is calculated for the nondegenerated electron gas both with an account and with no account of the exchange interaction

Distribution of arbuscular mycorrhizal fungi associated with different land use systems of Arunachal Pradesh of Eastern Himalayan region.

Science.gov (United States)

Bordoloi, A; Nath, P C; Shukla, A K

2015-10-01

Arbuscular mycorrhizal fungi are the main component of soil microbial population in most agroecosystems. They forms a close association with more than 80% of the plant species making immobilized mineral nutrients available to the plants in order to sustain normal growth and reproduction. In this study the diversity of mycorrhizal fungi has been examined in seven land use ecosystems of Arunachal Pradesh in Eastern Himalayan region. A total of 24 species of AM fungi belonging to 4 genera viz., Glomus, Scutellospora, Aculospora and Gigaspora were isolated from the soil samples collected from different land use systems. Glomus was the dominant genera and Glomus occulatum was the most abundant species in all the seven land use systems. Total spore number was highly variable among all the land use systems. Species richness was recorded highest in natural forest that maintains a faster nutrient cycle with the highest diversity index. The Jhum fallow land and tea garden has the least number of AM fungal species due to high disturbance of fire and application of fungicides and inorganic fertilizer. Further the plant species composition, particularly the ground vegetation coverage and disturbance level affects the distribution of the AM fungal species. In our study it has been shown that AMF diversity is significantly affected by the land use practices practiced by the people. Hence, the AM fungi isolated from different land use system may be useful in improving the agriculture practices particularly the plantation crops in the region.

Nigerian Journal of Biotechnology (Vol. 33)

African Journals Online (AJOL)

Ladaf 2

Screen house experiments were conducted at the Institute of Agricultural Research ... (Glomus clarum) and compost (sunflower) on the growth and yield of tomato plants. ... green foliage of this plant (Udo, 1982; John et al., tomato plants were ...

Practical electronics handbook

CERN Document Server

Sinclair, Ian R

2013-01-01

Practical Electronics Handbook, Third Edition provides the frequently used and highly applicable principles of electronics and electronic circuits.The book contains relevant information in electronics. The topics discussed in the text include passive and active discrete components; linear and digital I.C.s; microprocessors and microprocessor systems; digital-analogue conversions; computer aids in electronics design; and electronic hardware components.Electronic circuit constructors, service engineers, electronic design engineers, and anyone with an interest in electronics will find the book ve

Composition quantification of electron-transparent samples by backscattered electron imaging in scanning electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Müller, E., E-mail: erich.mueller@kit.edu; Gerthsen, D.

2017-02-15

The contrast of backscattered electron (BSE) images in scanning electron microscopy (SEM) depends on material parameters which can be exploited for composition quantification if some information on the material system is available. As an example, the In-concentration in thin In{sub x}Ga{sub 1−x}As layers embedded in a GaAs matrix is analyzed in this work. The spatial resolution of the technique is improved by using thin electron-transparent specimens instead of bulk samples. Although the BSEs are detected in a comparably small angular range by an annular semiconductor detector, the image intensity can be evaluated to determine the composition and local thickness of the specimen. The measured intensities are calibrated within one single image to eliminate the influence of the detection and amplification system. Quantification is performed by comparison of experimental and calculated data. Instead of using time-consuming Monte-Carlo simulations, an analytical model is applied for BSE-intensity calculations which considers single electron scattering and electron diffusion. - Highlights: • Sample thickness and composition are quantified by backscattered electron imaging. • A thin sample is used to achieve spatial resolution of few nanometers. • Calculations are carried out with a time-saving electron diffusion model. • Small differences in atomic number and density detected at low electron energies.

Fungal associations of roots of dominant and sub-dominant plants in high-alpine vegetation systems with special reference to mycorrhiza.

Science.gov (United States)

Haselwandter, K; Read, D J

1980-04-01

Types of root infection were analysed in healthy dominant and sub-dominant plants of zonal and azonal vegetation above the timberline in the Central and Northern Calcareous Alps of Austria. In the open nival zone vegetation, infection by fungi of the Rhizoctonia type was predominant, vesicular-arbuscular mycorrhizal infection, which was mostly of the fine endophyte (Glomus tenuis) type, being light and mainly restricted to grasses in closed vegetation patches. More extensive Glomus tenuis infection was found in the alpine grass heath, but in Carex, Rhizoctonia was again the most important fungus. The ericaceous plants of the dwarf shrub heath have typical ericoid infection, but quantitative analysis reveals a decrease of infection intensity with increase of altitude. The possible function of the various types of root infection are discussed, and the status of Rhizoctonia as a possible mycorrhizal fungus is considered.

Nonlinear electron-acoustic rogue waves in electron-beam plasma system with non-thermal hot electrons

Science.gov (United States)

Elwakil, S. A.; El-hanbaly, A. M.; Elgarayh, A.; El-Shewy, E. K.; Kassem, A. I.

2014-11-01

The properties of nonlinear electron-acoustic rogue waves have been investigated in an unmagnetized collisionless four-component plasma system consisting of a cold electron fluid, non-thermal hot electrons obeying a non-thermal distribution, an electron beam and stationary ions. It is found that the basic set of fluid equations is reduced to a nonlinear Schrodinger equation. The dependence of rogue wave profiles on the electron beam and energetic population parameter are discussed. The results of the present investigation may be applicable in auroral zone plasma.

Electron-cyclotron-resonant-heated electron distribution functions

International Nuclear Information System (INIS)

Matsuda, Y.; Nevins, W.M.; Cohen, R.H.

1981-01-01

Recent studies at Lawrence Livermore National Laboratory (LLNL) with a bounce-averaged Fokker-Planck code indicate that the energetic electron tail formed by electron-cyclotron resonant heating (ECRH) at the second harmonic is not Maxwellian. We present the results of our bounce-averaged Fokker-Planck code along with some simple analytic models of hot-electron distribution functions

Attainment of Electron Beam Suitable for Medium Energy Electron Cooling

International Nuclear Information System (INIS)

Seletskiy, Sergey M.; Rochester U.

2005-01-01

Electron cooling of charged particle beams is a well-established technique at electron energies of up to 300 keV. However, up to the present time the advance of electron cooling to the MeV-range energies has remained a purely theoretical possibility. The electron cooling project at Fermilab has recently demonstrated the first cooling of 8.9 GeV/c antiprotons in the Recycler ring, and therefore, has proved the validity of the idea of relativistic electron cooling. The Recycler Electron Cooler (REC) is the key component of the Tevatron Run II luminosity upgrade project. Its performance depends critically on the quality of electron beam. A stable electron beam of 4.3 MeV carrying 0.5 A of DC current is required. The beam suitable for the Recycler Electron Cooler must have an angular spread not exceeding 200 (micro)rad. The full-scale prototype of the REC was designed, built and tested at Fermilab in the Wideband laboratory to study the feasibility of attaining the high-quality electron beam. In this thesis I describe various aspects of development of the Fermilab electron cooling system, and the techniques used to obtain the electron beam suitable for the cooling process. In particular I emphasize those aspects of the work for which I was principally responsible. Chapter 1 is an introduction where I describe briefly the theory and the history of electron cooling, and derive the requirements to the quality of electron beam and requirements to the basic parameters of the Recycler Electron Cooler. Chapter 2 is devoted to the theoretical consideration of the motion of electrons in the cooling section, description of the cooling section and of the measurement of the magnetic fields. In Chapter 3 I consider different factors that increase the effective electron angle in the cooling section and suggest certain algorithms for the suppression of parasitic angles. Chapter 4 is devoted to the measurements of the energy of the electron beam. In the concluding Chapter 5 I review

Double differential distributions of electron emission in ion-atom and electron-atom collisions using an electron spectrometer

International Nuclear Information System (INIS)

Misra, Deepankar; Thulasiram, K.V.; Fernandes, W.; Kelkar, Aditya H.; Kadhane, U.; Kumar, Ajay; Singh, Yeshpal; Gulyas, L.; Tribedi, Lokesh C.

2009-01-01

We study electron emission from atoms and molecules in collisions with fast electrons and heavy ions (C 6+ ). The soft collision electrons (SE), two center electron emission (TCEE), the binary encounter (BE) events and the KLL Auger lines along with the elastically scattered peaks (in electron collisions) are studied using a hemispherical electrostatic electron analyzer. The details of the measurements along with description of the spectrometer and data acquisition system are given. The angular distributions of the low energy (few eV) electrons in soft collisions and the binary encounter electrons at keV energies are compared with quantum mechanical models based on the first Born (B1) and the continuum distorted wave-Eikonal initial state approximation (CDW-EIS).

VIRTUAL ELECTRONIC COMPONENTS OF THE ELECTRONIC EQUIPMENT

Directory of Open Access Journals (Sweden)

E. Lazarevich

2013-01-01

Full Text Available The article is present new idea of the creation, developments and improvements of the electronic equipment of complex systems by means of the virtual electronic components. The idea of the virtual electronic components is a presentation and perception of the creation and developments of the equipment on two forming: real – in the manner of standard marketed block of the intellectual property and image – in the manner of virtual component. The real component in most cases slows the development of the electronic equipment. The imaginary component is the «locomotive» of development of the electronic equipment. The Imaginary component contains the scientific has brushed against developer. The scientific has brushed against developer reveals of itself in the manner of virtual component on the modern level of the design rates of microelectronics.

Synergistic effect of Glomus fasciculatum and Trichoderma ...

African Journals Online (AJOL)

Firdaus-e-Bareen

2011-05-30

May 30, 2011 ... The effect of two soil amendments of tannery sludge (10% and 20%) on growth and metal uptake of. Helianthus annuus L. ... heavy metal polluted soils (Terry and Bañuelos, 2000). Although it is ..... remediation unit to treat contaminated soils containing a .... such as zinc, cadmium, lead, and arsenic. Rev.

Synergistic effect of Glomus fasciculatum and Trichoderma ...

African Journals Online (AJOL)

The plants treated with both fungus and mycorrhizal (F+M) treatment showed the maximum uptake of metals and thus the synergistic effect of these fungi can be exploited in decontamination of metals from tannery sludge. Key words: Phytoextraction, tannery sludge, heavy metals, resistant rhizosphere fungi, Arbuscular ...

Impact of arbuscular mycorrhizal fungus, Glomus intraradices ...

African Journals Online (AJOL)

Aghomotsegin

leaves were maximum in P. Poae + G.I inoculated plants under water deficit condition. In the presence of ... Plant growth promoting rhizobacteria (PGPR) are usually in contact ... plant hormone indole-3-acetic acid (IAA) and the pathways of its ...

A new stage of nuclear electronics-particle electronics

International Nuclear Information System (INIS)

Xi Deming

1987-01-01

The rapid development of high energy physics experiments has pushed the nuclear electronics to a new stage, i.e. the particle electronics. In this paper the background, main features and recent trends of the particle electronics are expounded

Electron transport effects in ion induced electron emission

Energy Technology Data Exchange (ETDEWEB)

Dubus, A. [Universite Libre de Bruxelles, Service de Metrologie Nucleaire (CP 165/84), 50 av. FD Roosevelt, B-1050 Brussels (Belgium)]. E-mail: adubus@ulb.ac.be; Pauly, N. [Universite Libre de Bruxelles, Service de Metrologie Nucleaire (CP 165/84), 50 av. FD Roosevelt, B-1050 Brussels (Belgium); Roesler, M. [Karl-Pokern-Str. 12, D-12587 Berlin (Germany)

2007-03-15

Ion induced electron emission (IIEE) is usually described as a three-step process, i.e. electron excitation by the incident projectile, electron transport (and multiplication) and electron escape through the potential barrier at the surface. In many cases, the first step of the process has been carefully described. The second step of the process, i.e. electron transport and multiplication, has often been treated in a very rough way, a simple decreasing exponential law being sometimes used. It is precisely the aim of the present work to show the importance of a correct description of electron transport and multiplication in a theoretical calculation of IIEE. A short overview of the electron transport models developed for IIEE is given in this work. The so-called 'Infinite medium slowing-down model' often used in recent works is evaluated by means of Monte Carlo simulations. In particular, the importance of considering correctly the semi-infinite character of the medium and the boundary condition at the vacuum-medium interface is discussed. Quantities like the electron escape depth are also briefly discussed. This evaluation has been performed in the particular case of protons (25keV

Studying electron-PAG interactions using electron-induced fluorescence

Science.gov (United States)

Narasimhan, Amrit; Grzeskowiak, Steven; Ostrander, Jonathan; Schad, Jonathon; Rebeyev, Eliran; Neisser, Mark; Ocola, Leonidas E.; Denbeaux, Gregory; Brainard, Robert L.

2016-03-01

In extreme ultraviolet (EUV) lithography, 92 eV photons are used to expose photoresists. Typical EUV resists are organic-based and chemically amplified using photoacid generators (PAGs). Upon exposure, PAGs produce acids which catalyze reactions that result in changes in solubility. In EUV lithography, photo- and secondary electrons (energies of 10- 80 eV) play a large role in PAG acid-production. Several mechanisms for electron-PAG interactions (e.g. electron trapping, and hole-initiated chemistry) have been proposed. The aim of this study is to explore another mechanism - internal excitation - in which a bound PAG electron can be excited by receiving energy from another energetic electron, causing a reaction that produces acid. This paper explores the mechanism of internal excitation through the analogous process of electron-induced fluorescence, in which an electron loses energy by transferring that energy to a molecule and that molecule emits a photon rather than decomposing. We will show and quantify electron-induced fluorescence of several fluorophores in polymer films to mimic resist materials, and use this information to refine our proposed mechanism. Relationships between the molecular structure of fluorophores and fluorescent quantum yield may aid in the development of novel PAGs for EUV lithography.

Electron-electron Thomas peak in fast transfer ionization

International Nuclear Information System (INIS)

Tolmanov, S. G.; McGuire, J. H.

2000-01-01

''Thomas process'' is a name used for a family of singular two-step processes that can lead to electron transfer. The Thomas process of the ''second kind,'' occurring in reactions with both transfer and ionization, utilizes the e-e scattering in the second step, so this Thomas process requires the dynamics of the electron-electron interaction. We calculate numerically the second order element of an S matrix and corresponding cross sections for the transfer ionization process. We find that the position and shape of the Thomas peak depend on both electron-electron and the electron-nucleus interaction. Also the direct and exchange amplitudes are equal at the peak position. We test the peaking approximation used for transfer ionization. Our results can be compared to experimental results for p + +He→H+He 2+ +e - . (c) 2000 The American Physical Society

Electron Tree

DEFF Research Database (Denmark)

Appelt, Ane L; Rønde, Heidi S

2013-01-01

The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

Electronic Raman response in electron-doped cuprate superconductors

International Nuclear Information System (INIS)

Geng Zhihao; Feng Shiping

2012-01-01

The electronic Raman response in the electron-doped cuprate superconductors is studied based on the t-t'-J model. It is shown that although the domelike shape of the doping dependent peak energy in the B 2g symmetry is a common feature for both electron-doped and hole-doped cuprate superconductors, there are pronounced deviations from a cubic response in the B 2g channel and a linear response in the B 2g channel for the electron-doped case in the low energy limit. It is also shown that these pronounced deviations are mainly caused by a nonmonotonic d-wave gap in the electron-doped cuprate superconductors.

Spectroscopy of electron irradiated polymers in electron microscope

International Nuclear Information System (INIS)

Faraj, S.H.; Salih, S.M.

1981-01-01

The damage induced by energetic electrons in the course of irradiation of polymers in a transmission electron microscope was investigated spectroscopically. Damage on the molecular level has been detected at very low exposure doses. These effects have been induced by electron doses less than that received by the specimen when it is situated at its usual place of the specimen stage in the electron microscope by a factor of 1,000. (author)

Electron spectroscopy in the fundamental process of electron-nucleus bremsstrahlung

International Nuclear Information System (INIS)

Hillenbrand, Pierre-Michel

2013-07-01

Within the scope of this thesis the fundamental process of electron-nucleus bremsstrahlung was studied in inverse kinematics at the Experimental Storage Ring ESR at GSI. For the system U 88+ + N 2 at 90 MeV/u it was shown, that by using inverse kinematics coincidence measurements between the scattered electron and the emitted photon can be performed for the case, in which the incoming electron transfers almost all of its kinetic energy onto the emitted photon. The sensitivity to the fundamental process could be achieved by measuring triple differential cross sections as a function of the emission angle of the photon and the scattered electron as well as the energy of the scattered electron. The optics of the magnetic electron spectrometer used were thoroughly revised and optimized to the experimental requirements. Analyzing different coincidences in this collision system, it was possible to determine the contributions to the electron distribution arising from radiative electron capture to the projectile continuum, nonradiative electron capture to the projectile continuum, and electron loss to the projectile continuum. The experimental results of each of these processes were compared to theoretical calculations. The electron spectra for the radiative and the nonradiative electron capture to continuum clearly reproduce the opposite asymmetry predicted by theory. Furthermore electron spectra for collisions of U 28+ with different gases were measured.

`Twisted' electrons

Science.gov (United States)

Larocque, Hugo; Kaminer, Ido; Grillo, Vincenzo; Leuchs, Gerd; Padgett, Miles J.; Boyd, Robert W.; Segev, Mordechai; Karimi, Ebrahim

2018-04-01

Electrons have played a significant role in the development of many fields of physics during the last century. The interest surrounding them mostly involved their wave-like features prescribed by the quantum theory. In particular, these features correctly predict the behaviour of electrons in various physical systems including atoms, molecules, solid-state materials, and even in free space. Ten years ago, new breakthroughs were made, arising from the new ability to bestow orbital angular momentum (OAM) to the wave function of electrons. This quantity, in conjunction with the electron's charge, results in an additional magnetic property. Owing to these features, OAM-carrying, or twisted, electrons can effectively interact with magnetic fields in unprecedented ways and have motivated materials scientists to find new methods for generating twisted electrons and measuring their OAM content. Here, we provide an overview of such techniques along with an introduction to the exciting dynamics of twisted electrons.

Vesicular arbuscular mycorrhizal fungi prevalence and diversity in ...

African Journals Online (AJOL)

The prevalence and population levels of VAM fungi in a range of field soil environments in Zimbabwe were determined. The main VAM genera Acaulospora, Scutellospora, Gigaspora, Glomus, Sclerocystis and Entrophospora were represented in the study sites. The relative abundance was ...

A comparison of the development and metabolic activity of mycorrhizas formed by arbuscular mycorrhizal fungi from different genera on two tropical forage legumes

NARCIS (Netherlands)

Boddington, C.L.; Dodd, J.C.

1998-01-01

Two glasshouse experiments were done to assess the development and metabolic activity of mycorrhizas formed by isolates of arbuscular mycorrhizal fungi (AMF) from three different genera, Acaulospora, Gigaspora and Glomus on either Pueraria phaseoloides L. or Desmodium ovalifolium L. plants. The

Produção e qualidade de óleos essenciais de Mentha arvensis em resposta à inoculação de fungos micorrízicos arbusculares Yield and quality of essential oils of Mentha arvensis in response to inoculation with arbuscular mycorrhizal fungi

Directory of Open Access Journals (Sweden)

Marta Simone Mendonça Freitas

2004-09-01

Full Text Available O objetivo deste trabalho foi avaliar os efeitos de diferentes espécies de fungos micorrízicos arbusculares (FMA na produção e qualidade de óleos essenciais de Mentha arvensis L., cultivada com diferentes doses de fósforo. O trabalho foi realizado em casa de vegetação e o delineamento estatístico utilizado foi de blocos ao acaso com 20 tratamentos, constituídos pela combinação de cinco tratamentos microbiológicos (Glomus clarum Nicolson & Schenck, Glomus etunicatum Becker & Gerdemann, Gigaspora margarita Becker & Hall, Acaulospora scrobiculata Trappe e controle e quatro doses de P (0, 50, 100 e 200 mg kg-1, com quatro repetições. As plantas foram colhidas 65 dias após o plantio. Sem adubação fosfatada, os fungos Gigaspora margarita e Glomus clarum aumentaram em 206 e 198%, respectivamente, a produção de matéria fresca em relação ao tratamento controle. A maior produção de matéria fresca (90 g por vaso foi observada no tratamento de A. scrobiculata com 133 mg kg-1 de fósforo. Na ausência de adubação fosfatada, teores de óleos essenciais e de mentol no óleo foram menores em plantas sem inoculação, e os tratamentos com inoculação proporcionaram incrementos de até 89% nos teores de óleos e de mentol, em relação ao tratamento sem inoculação. Com o incremento da adubação fosfatada, não foram observados incrementos dos teores de óleos essenciais e mentol em razão dos FMA. As maiores produtividades de óleos essenciais e de mentol nos óleos, 0,69 g e 0,48 g por vaso, respectivamente, foram encontradas em plantas com inoculação de Acaulospora scrobiculata nas doses de P de 126 e 123 mg kg-1 de solo, respectivamente.The objective of this work was to evaluate the effects of different species of arbuscular mycorrhizal fungi on the vegetative growth, production and composition of essential oil of Mentha arvensis L., grown in different phosphorus levels. The work was carried out under greenhouse conditions and

Aislamiento de consorcios de hongos micorrícicos arbusculares de plantas medicinales y su efecto en el crecimiento de vinca (Catharanthus roseus Isolation of arbuscular mycorrhizal fungi consortia from medicinal plants and their effectiveness on growth of vinca (Catharanthus roseus

Directory of Open Access Journals (Sweden)

CLAUDIA DE LA ROSA-MERA

2012-06-01

Full Text Available Este trabajo consistió en propagar e identificar hongos micorrícicos arbusculares (HMA recolectados de plantas medicinales (PM de áreas naturales de bosques mixtos, y seleccionar consorcios micorrícicos con base en la promoción del crecimiento de vinca Catharanthus roseus (L G. Don, planta medicinal cuyos alcaloides tienen propiedades antineoplásicas. En la primera fase experimental se recolectaron raíces y suelo rizosférico de 13 PM establecidas en campo para evaluar el porcentaje de colonización total (PCT y cuantificar el número de esporas; además, se tomó una parte del suelo para establecer plantas trampa en invernadero durante 10 meses, y posteriormente evaluar el PCT e identificar los principales géneros de HMA. Todas las PM en su condición natural presentaron colonización micorrícica, observándose cuatro géneros de HMA (Glomus, Acaulospora, Gigaspora y Scutellospora, de los cuales Acaulospora y Glomus fueron los predominantes. En la segunda fase experimental se seleccionaron ocho consorcios con base en el PCT (> 40 % obtenido en las plantas trampa, que correspondieron a las muestras recolectadas de Adiantum capillus-veneris L., Castilleja tenuiflora Benth., Erigeron karvinskianus DC., Pimpinella anisum L., Plantago major L., Ricinus communis L., Rubus fruticosus L. y Rumex mexicanus Meisn. Estos consorcios fueron inoculados en plántulas de C. roseus para evaluar su capacidad de estimular el crecimiento de esta especie en condiciones de invernadero. Después de 70 días, a pesar de presentar un solo género predominante (Glomus, el consorcio aislado de R. mexicanus promovió de manera más consistente el crecimiento de C. roseus (número de hojas, área foliar y peso seco foliar en comparación con el resto de los consorcios micorrícicos.This study consisted on propagating and identifying arbuscular mycorrhizal fungi (AMF collected from medicinal plants (MP of natural areas of mixed forest (Estado de Mexico, and

Successive cultivation of maize and agricultural practices on root colonization, number of spores and species of arbuscular mycorrhizal fungi Cultivo sucessivo de milho e práticas agrícolas sobre a colonização radical, número de esporos e de espécies de fungos micorrízicos arbusculares

Directory of Open Access Journals (Sweden)

Rosilaine Carrenho

2001-12-01

Full Text Available A large number of propagules and a broad spectrum of species are two important components of ecosystem (including agroecosystem sustainability. Previous studies carried out in temperate areas showed that repeated monoculture leads to a decrease in the species abundance of arbuscular mycorrhizal fungi (AMF. This study evaluated the influence of maize monoculture and its agricultural practices on AMF during three consecutive cropping years in a Brazilian field. At the end of each cycle, soil and root samples were evaluated for species composition, spore populations and root colonization by AMF. The AMF community present during this period was scored according to the Spearman rank correlation and Principal Components Analysis. The mean percent root colonization values for the three cultivation periods were: 66.9, 60.7 and 70.5, respectively. Seven species were detected in the first year, Scutellospora persica being the most abundant (24.1% of spores and Glomus macrocarpum the most observed (100% of samples. In the second year, Glomus etunicatum was the species with the greatest number of spores (24.7% and, like G. macrocarpum, the most frequently observed (90% in a community of thirteen. In the third year, twenty-three AMF species were identified, Scutellospora sp. 1 being the most abundant (17.4%, and Gigaspora decipiens and Glomus claroideum the most frequent (both with a relative frequency of 70%. The main soil factors influencing root colonization and sporulation by AMF were pH (and related properties, phosphorus and organic matter contents.Elevado número de propágulos e de espécies são componentes importantes para manter a sustentabilidade dos ecossistemas, incluindo agrossistemas. Estudos desenvolvidos em áreas temperadas indicaram que monocultivo prolongado conduziu ao decréscimo na abundância de esporos e de espécies de fungos micorrízicos arbusculares (FMA. O presente estudo avaliou a influência da monocultura de milho e de suas

Micorrizas arbusculares no crescimento de mudas de sabiá em um substrato proveniente da mineração de manganês

Directory of Open Access Journals (Sweden)

Kaio Gráculo Vieira Garcia

2016-04-01

Full Text Available O manganês (Mn é considerado um micronutriente essencial às plantas, porém o seu excesso pode resultar em toxidez, causando clorose e necrose nas folhas. O uso de leguminosas inoculadas com fungos micorrízicos arbusculares tem se tornado uma importante estratégia do ponto de vista da remediação de áreas contaminadas com metais como é o caso do manganês. Neste sentido, o objetivo deste trabalho foi avaliar o crescimento de mudas de Mimosa caesalpiniaefolia Benth. inoculadas com micorrizas arbusculares sob condições de substrato esterilizado e natural proveniente de uma área de mineração de Mn do município de Ocara – CE. O experimento foi conduzido em casa de vegetação, utilizando-se o delineamento inteiramente casualizado, em esquema fatorial 4x2, considerando-se: quatro tratamentos de inoculação (controle não-inoculado, inoculado com Glomus clarum, inoculado com Glomus etunicatum e com a mistura dos dois fungos (Mix e duas condições de substrato (estéril e natural, com quatro repetições. As mudas de sabiá foram produzidas em bandeja de isopor, sendo transplantadas e inoculadas em vasos após treze dias da semeadura. Após trinta dias do transplantio foram realizadas avaliações de altura da parte áerea, diâmetro do colo, número de folíolos e porcentagem de sobrevivência. A inoculação com fungos micorrízicos arbusculares favoreceu o crescimento das mudas de sabiá em substrato da mineração de manganês, em condições naturais, principalmente quando se utilizou o Glomus etunicatum. No substrato esterilizado a inoculação com micorrizas arbusculares proporcionou a atenuação da toxidez de Mn nas mudas de sabiá favorecendo o crescimento das mesmas nestas condições.Arbuscular mycorrhiza on the growth of sabiá seedlings on a substrate from the manganese miningAbstract: Manganese (Mn is considered an essential micronutrient to plants but its excess can result in toxicity causing chlorosis and necrosis on

The electron

International Nuclear Information System (INIS)

Hestenes, David; Weingartshofer, Antonio

1991-01-01

The stupendous successes of the Dirac equation and quantum electro-dynamics have established the electron as the best understood of the fundamental constituents of matter. Nevertheless, physicists agree that the electron still has secrets to reveal. Moreover, powerful new theoretical and experimental tools for probing those secrets have been sharpened during the last decade. This workshop was organized to bring theorists and experimentalists together to discuss their common goal of knowing the electron. Present state and future prospects for progress toward that goal are here described. The theoretical papers encompass a wide range of views on the electron. Several argue that the 'Zitter-bewegung' is more than a mathematical peculiarity of the Dirac equation, that it may well be a real physical phenomenon and worthy of serious study, theoretically and experimentally. Besides generating the electron spin and magnetic moment, the 'Zitterbewegung' may be a vital clue to electron structure and self-interaction. Some of the papers employ a radical new formulation of the Dirac theory which reveals a hidden geo-metric structure in the theory that supports a 'Zitterbewegung' inter-pretation. For the last half century the properties of electrons have been probed primarily by scattering experiments at ever higher energies. Recently, however, two powerful new experimental techniques have emerged capable of giving alternative experimental views of the electron. First, techniques for confining single electrons for long term study have led to the most accurate measurements of the electron magnetic moment. Second, the interaction of high intensity laser fields with atoms and electrons have revealed striking new phenomena such as multiphoton ionization. refs.; figs.; tabs

Basic electronics

CERN Document Server

Holbrook, Harold D

1971-01-01

Basic Electronics is an elementary text designed for basic instruction in electricity and electronics. It gives emphasis on electronic emission and the vacuum tube and shows transistor circuits in parallel with electron tube circuits. This book also demonstrates how the transistor merely replaces the tube, with proper change of circuit constants as required. Many problems are presented at the end of each chapter. This book is comprised of 17 chapters and opens with an overview of electron theory, followed by a discussion on resistance, inductance, and capacitance, along with their effects on t

Electron-electron scattering and mobilities in semiconductors and quantum wells

International Nuclear Information System (INIS)

Lyo, S.K.

1986-01-01

The effect of electron-electron scattering on the mobility in semiconductors and semiconductor quantum wells is examined. A general exact formula is derived for the mobility, when the electron-electron collision rate is much faster than other scattering rates such as those by ionized impurities and phonons. In this limit, the transport relaxation rate is independent of the carrier's energy and contributions to the inverse mobility from individual scattering mechanism add up. The mobility becomes significantly reduced from its value in the absence of electron-electron scattering. When the collision rates are not necessarily dominated by electron-electron scattering, the mobility is calculated by the Kohler-Sondheimer variational method in the presence of ionized-impurity scattering and acoustic-phonon scattering in a nondegenerate two-dimensional quantum well

Modified Monte Carlo method for study of electron transport in degenerate electron gas in the presence of electron-electron interactions, application to graphene

Science.gov (United States)

Borowik, Piotr; Thobel, Jean-Luc; Adamowicz, Leszek

2017-07-01

Standard computational methods used to take account of the Pauli Exclusion Principle into Monte Carlo (MC) simulations of electron transport in semiconductors may give unphysical results in low field regime, where obtained electron distribution function takes values exceeding unity. Modified algorithms were already proposed and allow to correctly account for electron scattering on phonons or impurities. Present paper extends this approach and proposes improved simulation scheme allowing including Pauli exclusion principle for electron-electron (e-e) scattering into MC simulations. Simulations with significantly reduced computational cost recreate correct values of the electron distribution function. Proposed algorithm is applied to study transport properties of degenerate electrons in graphene with e-e interactions. This required adapting the treatment of e-e scattering in the case of linear band dispersion relation. Hence, this part of the simulation algorithm is described in details.

Attainment of Electron Beam Suitable for Medium Energy Electron Cooling

Energy Technology Data Exchange (ETDEWEB)

Seletskiy, Sergei M. [Univ. of Rochester, NY (United States)

2005-01-01

Electron cooling of charged particle beams is a well-established technique at electron energies of up to 300 keV. However, up to the present time the advance of electron cooling to the MeV-range energies has remained a purely theoretical possibility. The electron cooling project at Fermilab has recently demonstrated the ¯rst cooling of 8.9 GeV/c antiprotons in the Recycler ring, and therefore, has proved the validity of the idea of relativistic electron cool- ing. The Recycler Electron Cooler (REC) is the key component of the Teva- tron Run II luminosity upgrade project. Its performance depends critically on the quality of electron beam. A stable electron beam of 4.3 MeV car- rying 0.5 A of DC current is required. The beam suitable for the Recycler Electron Cooler must have an angular spread not exceeding 200 ¹rad. The full-scale prototype of the REC was designed, built and tested at Fermilab in the Wideband laboratory to study the feasibility of attaining the high-quality electron beam. In this thesis I describe various aspects of development of the Fermilab electron cooling system, and the techniques used to obtain the electron beam suitable for the cooling process. In particular I emphasize those aspects of the work for which I was principally responsible.

Microfluidic electronics.

Science.gov (United States)

Cheng, Shi; Wu, Zhigang

2012-08-21

Microfluidics, a field that has been well-established for several decades, has seen extensive applications in the areas of biology, chemistry, and medicine. However, it might be very hard to imagine how such soft microfluidic devices would be used in other areas, such as electronics, in which stiff, solid metals, insulators, and semiconductors have previously dominated. Very recently, things have radically changed. Taking advantage of native properties of microfluidics, advances in microfluidics-based electronics have shown great potential in numerous new appealing applications, e.g. bio-inspired devices, body-worn healthcare and medical sensing systems, and ergonomic units, in which conventional rigid, bulky electronics are facing insurmountable obstacles to fulfil the demand on comfortable user experience. Not only would the birth of microfluidic electronics contribute to both the microfluidics and electronics fields, but it may also shape the future of our daily life. Nevertheless, microfluidic electronics are still at a very early stage, and significant efforts in research and development are needed to advance this emerging field. The intention of this article is to review recent research outcomes in the field of microfluidic electronics, and address current technical challenges and issues. The outlook of future development in microfluidic electronic devices and systems, as well as new fabrication techniques, is also discussed. Moreover, the authors would like to inspire both the microfluidics and electronics communities to further exploit this newly-established field.

[Phosphorus transfer between mixed poplar and black locust seedlings].

Science.gov (United States)

He, Wei; Jia, Liming; Hao, Baogang; Wen, Xuejun; Zhai, Mingpu

2003-04-01

In this paper, the 32P radio-tracer technique was applied to study the ways of phosphorus transfer between poplar (Populus euramericana cv. 'I-214') and black locust (Robinia pseudoacacia). A five compartment root box (18 cm x 18 cm x 26 cm) was used for testing the existence of the hyphal links between the roots of two tree species when inoculated with vesicular-arbuscular (VA) mycorrhizal fungus (Glomus mosseae). Populus I-214 (donor) and Robinia pseudoacacia (receiver) were grown in two terminal compartments, separated by a 2 cm root-free soil layer. The root compartments were lined with bags of nylon mesh (38 microns) that allowed the passage of hyphae but not roots. The top soil of a mixed stand of poplar and black locust, autoclaved at 121 degrees C for one hour, was used for growing seedlings for testing. In 5 compartment root box, mycorrhizal root colonization of poplar was 34%, in which VA mycorrhizal fungus was inoculated, whereas 26% mycorrhizal root colonization was observed in black locust, the other terminal compartment, 20 weeks after planting. No root colonization was observed in non-inoculated plant pairs. This indicated that the mycorrhizal root colonization of black locust was caused by hyphal spreading from the poplar. Test of tracer isotope of 32P showed that the radioactivity of the treatment significantly higher than that of the control (P mycorrhizal fungus was inoculated in poplar root. Furthermore, mycorrhizal interconnections between the roots of poplar and black locust seedlings was observed in situ by binocular in root box. All these experiments showed that the hyphal links was formed between the roots of two species of trees inoculated by VA mycorrhizal fungus. Four treatments were designed according to if there were two nets (mesh 38 microns), 2 cm apart, between the poplar and black locust, and if the soil in root box was pasteurized. Most significant differences of radioactivity among four treatments appeared 44 days after feeding

Electron-electron collision effects on the bremsstrahlung emission in Lorentzian plasmas

International Nuclear Information System (INIS)

Jung, Young-Dae; Kato, Daiji

2009-01-01

Electron-electron collision effects on the electron-ion bremsstrahlung process are investigated in Lorentzian plasmas. The effective electron-ion interaction potential is obtained by including the far-field terms caused by electron-electron collisions with an effective Debye length in Lorentzian plasmas. The bremsstrahlung radiation cross section is obtained as a function of the electron energy, photon energy, collision frequency, spectral index and Debye length using the Born approximation for the initial and final states of the projectile electron. It is shown that the non-Maxwellian character suppresses the bremsstrahlung radiation cross section. It is also shown that the electron-electron collision effect enhances the bremsstrahlung emission spectrum. In addition, the bremsstrahlung radiation cross section decreases with an increase in the plasma temperature.

Electron-photon and electron-electron interactions in the presence of strong electromagnetic fields

International Nuclear Information System (INIS)

Surzhykov, A.; Fritzsche, S.; Stoehlker, Th.

2010-01-01

During the last decade, photon emission from highly-charged, heavy ions has been in the focus of intense studies at the GSI accelerator and storage ring facility in Darmstadt. These studies have revealed unique information about the electron-electron and electron-photon interactions in the presence of extremely strong nuclear fields. Apart from the radiative electron capture processes, characteristic photon emission following collisional excitation of projectile ions has also attracted much interest. In this contribution, we summarize the recent theoretical studies on the production of excited ionic states and their subsequent radiative decay. We will pay special attention to the angular and polarization properties of Kα emission from helium-like ions produced by means of dielectronic recombination. The results obtained for this (resonant) capture process will be compared with the theoretical predictions for the characteristic X-rays following Coulomb excitation and radiative recombination of few-electron, heavy ions. Work is supported by Helmholtz Association and GSl under the project VH-NG--421. (author)

Sticker electronics

KAUST Repository

Hussain, Muhammad Mustafa

2017-09-08

Electronic stickers may be manufactured on flexible substrates (110, 120, 130) as layers and packaged together. The package may then have an adhesive applied to one side to provide capability for sticking the electronic devices to surfaces. The stickers can be wrappable, placed on surfaces, glued on walls or mirrors or wood or stone, and have electronics (112, 122, 132) which may or may not be ultrathin. Packaging for the electronic sticker can use polymer on cellulose manufacturing and/or three dimensional (3-D) printing. The electronic stickers may provide lighting capability, sensing capability, and/or recharging capabilities.

Electronic Commerce

Directory of Open Access Journals (Sweden)

Slavko Đerić

2016-12-01

Full Text Available Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks, including the Internet. Electronic commerce is not limited just to buying and selling, but it also includes all pre-sales and after-sales ongoing activities along the supply chain. Introducing electronic commerce, using the Internet and Web services in business, realizes the way to a completely new type of economy - internet economy.

Anatomy and ultrastructure alterations of Leucaena leucocephala (Lam.) inoculated with mycorrhizal fungi in response to arsenic-contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Schneider, Jerusa, E-mail: jerusaschneider@hotmail.com [Departamento de Ciência do Solo, Universidade Federal de Lavras (UFLA), PO Box 3037, Lavras, Minas Gerais, 37200-000 (Brazil); Labory, Claudia Regina Gontijo [Departamento de Fitopatologia, Universidade Federal de Lavras, PO Box 3037, Lavras, Minas Gerais, 37200-000 (Brazil); Rangel, Wesley Melo [Departamento de Ciência do Solo, Universidade Federal de Lavras (UFLA), PO Box 3037, Lavras, Minas Gerais, 37200-000 (Brazil); Alves, Eduardo [Departamento de Fitopatologia, Universidade Federal de Lavras, PO Box 3037, Lavras, Minas Gerais, 37200-000 (Brazil); Guilherme, Luiz Roberto Guimarães [Departamento de Ciência do Solo, Universidade Federal de Lavras (UFLA), PO Box 3037, Lavras, Minas Gerais, 37200-000 (Brazil)

2013-11-15

Highlights: ► Inoculation of L. leucocephala improved plant growth in high-As soils. ► Plants inoculated with Glomus clarum were less sensitive to As. ► Ultrastructural changes in leaves of L. leucocephala. ► Modified structures in intracellular spaces in plants inoculated with G. clarum. ► Cell disruption and stacking of root cell walls at high As concentrations. -- Abstract: Many studies demonstrate the potential application of arbuscular mycorrhizal fungi (AMF) for remediation purposes, but little is known on AMF potential to enhance plant tolerance to arsenic (As) and the mechanisms involved in this process. We carried anatomical and ultrastructural studies to examine this symbiotic association and the characteristics of shoots and roots of Leucaena leucocephala in As-amended soils (35 and 75 mg As dm{sup −3}). The experiment used 3 AMF isolates from uncontaminated soils: Acaulospora morrowiae, Glomus clarum, and Gigaspora albida; a mixed inoculum derived from combining these 3 isolates (named Mix AMF); and, 3 AMF isolates from As-contaminated areas: A. morrowiae, G. clarum and Paraglomus occultum. Phytotoxicity symptoms due to arsenic contamination appeared during plant growth, especially in treatments without AMF application. Inoculation with G. clarum and the mixture of species (A. morrowiae, G. albida, and G. clarum) resulted in better growth of L. leucocephala in soils with high As concentrations, as well as significant As removal from the soil, showing a potential for using AMF in phytoextraction. Light microscopy (LS), transmission (TEM) and scanning electron microscopies (SEM) studies showed the colonization of the AMF in plant tissues and damage in all treatments, with ultrastructural changes being observed in leaves and roots of L. leucocephala, especially with the addition of 75 mg dm{sup −3} of As.

Observation of the two-electron cusp in atomic collisions. Evidence for strong electron-electron correlation

International Nuclear Information System (INIS)

Sarkadi, L.; Orban, A.

2007-01-01

Complete text of publication follows. In this report we present experimental data for a process when two electrons with velocity vectors equal to that of the projectile are emitted from collisions. By observing the two electron cusp the study of the threshold phenomenon for two-electron break-up is possible. It is a particularly interesting question whether the outgoing charged projectile can attract the two repulsing electrons so strongly that the two-electron cusp is formed. If it is so, a further question arises: Are the two electrons correlated in the final state as it is predicted by the Wannier theory? The experiments have been done at the 1 MeV VdG accelerator of ATOMKI using our TOF spectrometer. The first measurements clearly showed the formation of the two-electron cusp and signature of the electron correlation in 200 keV He 0 +He collisions. These promising results motivated us to carry out the experiment at 100 keV beam energy where the coincidence count rate is still reasonable but the energy resolution is better. For an acceptable data acquisition time we improved our data acquisition and data processing system for triple coincidence measurements. In Fig. 1a we present our measured relative fourfold differential cross section (FDCS) that shows strong electron correlation. For a comparison, in Fig. 1b we displayed the contour plot for uncorrelated electron pair emission. These latter data were synthesized artificially, generating the energies of the electron pairs from two independent double coincidence experiments. In both figures the distributions are characterized by two ridges. In Fig. 1b the ridges are perpendicular straight lines (E 1 = E 2 .13.6 eV). As a result of the correlation, the ridges in Fig. 1a are distorted in such a way that they have a joint straight-line section following the line E 1 + E 2 = 27.2 eV. This means that the electron pairs in the vicinity of the cusp maximum are emitted with a center of- mass velocity equal to that of

Electronics and Information

Institute of Scientific and Technical Information of China (English)

无

2008-01-01

@@ Previously founded as CCPITMachinery and Electronics Sub-council and CCOIC Machinery and Electronics Chamber of Corn-merce in June, 1988, CCPIT Electronics Sub-Council and CCOIC Electronics Chamber of Commerce were established in May, 1993, and then renamed as CCPIT Electronics and Information Industry Sub-council and CCOIC Electronics and Infor-mation Industry Chamber of Commerce (CCPITECC) in September 1999.

Spontaneous and stimulated emission induced by an electron, electron bunch, and electron beam in a plasma

International Nuclear Information System (INIS)

Kuzelev, M V; Rukhadze, A A

2008-01-01

Two fundamental mechanisms - the Cherenkov effect and anomalous Doppler effect - underlying the emission by an electron during its superluminal motion in medium are considered. Cherenkov emission induced by a single electron and a small electron bunch is spontaneous. In the course of spontaneous Cherenkov emission, the translational motion of an electron is slowed down and the radiation energy grows linearly with time. As the number of radiating electrons increases, Cherenkov emission becomes stimulated. Stimulated Cherenkov emission represents a resonance beam instability. This emission process is accompanied by longitudinal electron bunching in the beam or by the breaking of an electron bunch into smaller bunches, in which case the radiation energy grows exponentially with time. In terms of the longitudinal size L e of the electron bunch there is a transition region λ e 0 -1 between the spontaneous and stimulated Cherenkov effects, where λ is the average radiation wavelength, and δ 0 is the dimensionless (in units of the radiation frequency) growth rate of the Cherenkov beam instability. The range to the left of this region is dominated by spontaneous emission, whereas the range to the right of this region is dominated by stimulated emission. In contrast to the Vavilov-Cherenkov effect, the anomalous Doppler effect should always (even for a single electron) be considered as stimulated, because it can only be explained by accounting for the reverse action of the radiation field on the moving electron. During stimulated emission in conditions where anomalous Doppler effect shows itself, an electron is slowed down and spins up; in this case, the radiation energy grows exponentially with time. (reviews of topical problems)

High perveance electron gun for the electron cooling system

International Nuclear Information System (INIS)

Korotaev, Yu.; Meshkov, I.; Petrov, A.; Sidorin, A.; Smirnov, A.; Syresin, E.; Titkova, I.

2000-01-01

The cooling time in the electron cooling system is inversely proportional to the beam current. To obtain high current of the electron beam the control electrode of the gun is provided with a positive potential and an electrostatic trap for secondary electrons appears inside the electron gun. This leads to a decrease in the gun perveance. To avoid this problem, the adiabatic high perveance electron gun with the clearing control electrode is designed in JINR (J. Bosser, Y. Korotaev, I. Meshkov, E. Syresin et al., Nucl. Instr. and Meth. A 391 (1996) 103. Yu. Korotaev, I. Meshkov, A. Sidorin, A. Smirnov, E. Syresin, The generation of electron beams with perveance of 3-6 μA/V 3/2 , Proceedings of SCHEF'99). The clearing control electrode has a transverse electric field, which clears secondary electrons. Computer simulations of the potential map were made with RELAX3D computer code (C.J. Kost, F.W. Jones, RELAX3D User's Guide and References Manual)

High perveance electron gun for the electron cooling system

CERN Document Server

Korotaev, Yu V; Petrov, A; Sidorin, A; Smirnov, A; Syresin, E M; Titkova, I

2000-01-01

The cooling time in the electron cooling system is inversely proportional to the beam current. To obtain high current of the electron beam the control electrode of the gun is provided with a positive potential and an electrostatic trap for secondary electrons appears inside the electron gun. This leads to a decrease in the gun perveance. To avoid this problem, the adiabatic high perveance electron gun with the clearing control electrode is designed in JINR (J. Bosser, Y. Korotaev, I. Meshkov, E. Syresin et al., Nucl. Instr. and Meth. A 391 (1996) 103. Yu. Korotaev, I. Meshkov, A. Sidorin, A. Smirnov, E. Syresin, The generation of electron beams with perveance of 3-6 mu A/V sup 3 sup / sup 2 , Proceedings of SCHEF'99). The clearing control electrode has a transverse electric field, which clears secondary electrons. Computer simulations of the potential map were made with RELAX3D computer code (C.J. Kost, F.W. Jones, RELAX3D User's Guide and References Manual).

Study of single-electron excitations by electron microscopy

International Nuclear Information System (INIS)

Craven, A.J.; Gibson, J.M.; Howie, A.; Spalding, D.R.

1978-01-01

The inelastic scattering of fast electrons by the excitation of L-shell electrons at a stacking fault in silicon has been studied with a scanning transmission electron microscope. It was found that the bright-field stacking fault contrast is preserved in the filtered L-shell-loss signal at 100 eV. This result is discussed in terms of the delocalization of the excitation mechanism. It is concluded that localization effects will typically become significant only for energy transfers greater than 1 keV from a fast electron of energy 80 keV. (author)

Syringe injectable electronics

Science.gov (United States)

Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M.

2015-01-01

Seamless and minimally-invasive three-dimensional (3D) interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating syringe injection and subsequent unfolding of submicrometer-thick, centimeter-scale macroporous mesh electronics through needles with a diameter as small as 100 micrometers. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with > 90% device yield. We demonstrate several applications of syringe injectable electronics as a general approach for interpenetrating flexible electronics with 3D structures, including (i) monitoring of internal mechanical strains in polymer cavities, (ii) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (iii) in vivo multiplexed neural recording. Moreover, syringe injection enables delivery of flexible electronics through a rigid shell, delivery of large volume flexible electronics that can fill internal cavities and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics. PMID:26053995

Electronic Nose and Electronic Tongue

Science.gov (United States)

Bhattacharyya, Nabarun; Bandhopadhyay, Rajib

Human beings have five senses, namely, vision, hearing, touch, smell and taste. The sensors for vision, hearing and touch have been developed for several years. The need for sensors capable of mimicking the senses of smell and taste have been felt only recently in food industry, environmental monitoring and several industrial applications. In the ever-widening horizon of frontier research in the field of electronics and advanced computing, emergence of electronic nose (E-Nose) and electronic tongue (E-Tongue) have been drawing attention of scientists and technologists for more than a decade. By intelligent integration of multitudes of technologies like chemometrics, microelectronics and advanced soft computing, human olfaction has been successfully mimicked by such new techniques called machine olfaction (Pearce et al. 2002). But the very essence of such research and development efforts has centered on development of customized electronic nose and electronic tongue solutions specific to individual applications. In fact, research trends as of date clearly points to the fact that a machine olfaction system as versatile, universal and broadband as human nose and human tongue may not be feasible in the decades to come. But application specific solutions may definitely be demonstrated and commercialized by modulation in sensor design and fine-tuning the soft computing solutions. This chapter deals with theory, developments of E-Nose and E-Tongue technology and their applications. Also a succinct account of future trends of R&D efforts in this field with an objective of establishing co-relation between machine olfaction and human perception has been included.

A theory of electron baths: One-electron system dynamics

International Nuclear Information System (INIS)

McDowell, H.K.

1992-01-01

The second-quantized, many-electron, atomic, and molecular Hamiltonian is partitioned both by the identity or labeling of the spin orbitals and by the dynamics of the spin orbitals into a system coupled to a bath. The electron bath is treated by a molecular time scale generalized Langevin equation approach designed to include one-electron dynamics in the system dynamics. The bath is formulated as an equivalent chain of spin orbitals through the introduction of equivalent-chain annihilation and creation operators. Both the dynamics and the quantum grand canonical statistical properties of the electron bath are examined. Two versions for the statistical properties of the bath are pursued. Using a weak bath assumption, a bath statistical average is defined which allows one to achieve a reduced dynamics description of the electron system which is coupled to the electron bath. In a strong bath assumption effective Hamiltonians are obtained which reproduce the dynamics of the bath and which lead to the same results as found in the weak bath assumption. The effective (but exact) Hamiltonian is found to be a one-electron Hamiltonian. A reduced dynamics equation of motion for the system population matrix is derived and found to agree with a previous version. This equation of motion is useful for studying electron transfer in the system when coupled to an electron bath

Treatment of foods with 'soft-electrons' (low-energy electrons)

International Nuclear Information System (INIS)

Hayashi, Toru; Todoriki, Setsuko

2003-01-01

Electrons with energies of 300 keV or lower were defined as soft-electrons'. Soft-electrons can eradicate microorganisms residing on the surface of grains, pulses, spices, dehydrated vegetables, tea leaves and seeds, and reduce their microbial loads to levels lower than 10 CFU/g with little quality deterioration. Soft-electrons can inactivate insect pests infesting grains and pulses and inhibit sprouting of potatoes. (author)

Compact femtosecond electron diffractometer with 100 keV electron bunches approaching the single-electron pulse duration limit

International Nuclear Information System (INIS)

Waldecker, Lutz; Bertoni, Roman; Ernstorfer, Ralph

2015-01-01

We present the design and implementation of a highly compact femtosecond electron diffractometer working at electron energies up to 100 keV. We use a multi-body particle tracing code to simulate electron bunch propagation through the setup and to calculate pulse durations at the sample position. Our simulations show that electron bunches containing few thousands of electrons per bunch are only weakly broadened by space-charge effects and their pulse duration is thus close to the one of a single-electron wavepacket. With our compact setup, we can create electron bunches containing up to 5000 electrons with a pulse duration below 100 fs on the sample. We use the diffractometer to track the energy transfer from photoexcited electrons to the lattice in a thin film of titanium. This process takes place on the timescale of few-hundred femtoseconds and a fully equilibrated state is reached within 1 ps

Electron backscattering for process control in electron beam welding

International Nuclear Information System (INIS)

Ardenne, T. von; Panzer, S.

1983-01-01

A number of solutions to the automation of electron beam welding is presented. On the basis of electron backscattering a complex system of process control has been developed. It allows an enlarged imaging of the material's surface, improved adjustment of the beam focusing and definite focus positioning. Furthermore, both manual and automated positioning of the electron beam before and during the welding process has become possible. Monitoring of the welding process for meeting standard welding requirements can be achieved with the aid of a control quantity derived from the results of electronic evaluation of the high-frequency electron backscattering

Electron transfer reactions

CERN Document Server

Cannon, R D

2013-01-01

Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

Understand electronics

CERN Document Server

Bishop, Owen

2013-01-01

Understand Electronics provides a readable introduction to the exciting world of electronics for the student or enthusiast with little previous knowledge. The subject is treated with the minimum of mathematics and the book is extensively illustrated.This is an essential guide for the newcomer to electronics, and replaces the author's best-selling Beginner's Guide to Electronics.The step-by-step approach makes this book ideal for introductory courses such as the Intermediate GNVQ.

Electronic Commerce

OpenAIRE

Slavko Đerić

2016-01-01

Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks...

2373-IJBSC-Article-Banito Agnassim

African Journals Online (AJOL)

hp

In a column values with the same letter are not significantly different at 5% level with Duncan's Multiple Range. Test. M233, M353, B3 and Gd = Glomus strains .... Castillo CG, Puccio F, Morales D, Borie F,. Sieverding E. 2012. Early arbuscular.

The resource investigation and community structure characteristics ...

African Journals Online (AJOL)

Jane

2011-06-27

Jun 27, 2011 ... Chinese fir is one of the most important commercial timber species in south China. ... distribution also associated with seasons and forest age; the most active season .... dry soil, 36.0, 12.08 and 48.08%, the IV of Glomus was.

Differential access to phosphorus pools of an Oxisol by mycorrhizal and non-mycorrhizal maize

NARCIS (Netherlands)

Cardoso, I.M.; Boddington, C.L.; Janssen, B.H.; Oenema, O.; Kuyper, T.W.

2006-01-01

This study investigated whether arbuscular mycorrhizal fungi (AMF) could take up phosphorus (P) from pools that are normally considered unavailable to plants. An aluminum (Al) resistant maize variety, inoculated with three species of Glomus or uninoculated, supplied with nutrient solution without P,

USER MANUAL: A Practical Guide to Inoculation with Arbuscular Mycorrhizal Fungi in Ecological Restoration

Science.gov (United States)

2017-06-05

Cetraspora, Gig : Gigaspora, Cla: Claroideoglomus, Glo: Glomus, Fun: Funneliformis, Sep: Septoglomus, Rhi: Rhizoglomus, Amb: Ambispora, Arc: Archaeospora...Lester, A. Livengood, A. Davis, and L. Yonavjak. 2015. Estimating the Size and Impact of the Ecological Restoration Economy . PloS one 10:e0128339

Photon and electron collimator effects on electron output and abutting segments in energy modulated electron therapy

International Nuclear Information System (INIS)

Olofsson, Lennart; Karlsson, Magnus G.; Karlsson, Mikael

2005-01-01

In energy modulated electron therapy a large fraction of the segments will be arranged as abutting segments where inhomogeneities in segment matching regions must be kept as small as possible. Furthermore, the output variation between different segments should be minimized and must in all cases be well predicted. For electron therapy with add-on collimators, both the electron MLC (eMLC) and the photon MLC (xMLC) contribute to these effects when an xMLC tracking technique is utilized to reduce the x-ray induced leakage. Two add-on electron collimator geometries have been analyzed using Monte Carlo simulations: One isocentric eMLC geometry with an isocentric clearance of 35 cm and air or helium in the treatment head, and one conventional proximity geometry with a clearance of 5 cm and air in the treatment head. The electron fluence output for 22.5 MeV electrons is not significantly affected by the xMLC if the shielding margins are larger than 2-3 cm. For small field sizes and 9.6 MeV electrons, the isocentric design with helium in the treatment head or shielding margins larger than 3 cm is needed to avoid a reduced electron output. Dose inhomogeneity in the matching region of electron segments is, in general, small when collimator positions are adjusted to account for divergence in the field. The effect of xMLC tracking on the electron output can be made negligible while still obtaining a substantially reduced x-ray leakage contribution. Collimator scattering effects do not interfere significantly when abutting beam techniques are properly applied

Equation satisfied by electron-electron mutual Coulomb repulsion energy density functional

OpenAIRE

Joubert, Daniel P.

2011-01-01

The electron-electron mutual Coulomb repulsion energy density functional satisfies an equation that links functionals and functional derivatives at N-electron and (N-1)-electron densities for densities determined from the same adiabatic scaled external potential for the N-electron system.

Electronic Publishing.

Science.gov (United States)

Lancaster, F. W.

1989-01-01

Describes various stages involved in the applications of electronic media to the publishing industry. Highlights include computer typesetting, or photocomposition; machine-readable databases; the distribution of publications in electronic form; computer conferencing and electronic mail; collaborative authorship; hypertext; hypermedia publications;…

Syringe-injectable electronics.

Science.gov (United States)

Liu, Jia; Fu, Tian-Ming; Cheng, Zengguang; Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M

2015-07-01

Seamless and minimally invasive three-dimensional interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating the syringe injection (and subsequent unfolding) of sub-micrometre-thick, centimetre-scale macroporous mesh electronics through needles with a diameter as small as 100 μm. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with >90% device yield. We demonstrate several applications of syringe-injectable electronics as a general approach for interpenetrating flexible electronics with three-dimensional structures, including (1) monitoring internal mechanical strains in polymer cavities, (2) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (3) in vivo multiplexed neural recording. Moreover, syringe injection enables the delivery of flexible electronics through a rigid shell, the delivery of large-volume flexible electronics that can fill internal cavities, and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics.

Electronic excitation of Na atom by electron impact

International Nuclear Information System (INIS)

Bielschowsky, C.E.; Souza, G.G.B. de; Lucas, C.A.; Nogueira, J.C.

1988-01-01

Electronic excitation of the 3s-3p transition in the Na atom was studied by intermediate energy electron impact spectroscopy. Differential Cross Sections (DCS) and Generalized Oscillator Strenghts (GOS) were determined experimentally for 1 KeV electrons. Theoretical results within the First Born Approximation as well as Glauber theory, were also performed. (A.C.A.S.) [pt

Highly efficient electron gun with a single-atom electron source

International Nuclear Information System (INIS)

Ishikawa, Tsuyoshi; Urata, Tomohiro; Cho, Boklae; Rokuta, Eiji; Oshima, Chuhei; Terui, Yoshinori; Saito, Hidekazu; Yonezawa, Akira; Tsong, Tien T.

2007-01-01

The authors have demonstrated highly collimated electron-beam emission from a practical electron gun with a single-atom electron source; ∼80% of the total emission current entered the electron optics. This ratio was two or three orders of magnitude higher than those of the conventional electron sources such as a cold field emission gun and a Zr/O/W Schottky gun. At the pressure of less than 1x10 -9 Pa, the authors observed stable emission of 20 nA, which generates the specimen current of 5 pA required for scanning electron microscopes

Electron-electron interaction in p-SiGe/Ge quantum wells

International Nuclear Information System (INIS)

Roessner, Benjamin; Kaenel, Hans von; Chrastina, Daniel; Isella, Giovanni; Batlogg, Bertram

2005-01-01

The temperature dependent magnetoresistance of high mobility p-SiGe/Ge quantum wells is studied with hole densities ranging from 1.7 to 5.9 x 10 11 cm -2 . At magnetic fields below the onset of quantum oscillations that reflect the high mobility values (up to 75000 cm 2 /Vs), we observe the clear signatures of electron-electron interaction. We compare our experiment with the theory of electron-electron interaction including the Zeeman band splitting. The observed magnetoresistance is well explained as a superposition of band structure induced positive magnetoresistance and the negative magntoresistance due to the electron-electron interaction effect

Electron-electron interactions in disordered systems

CERN Document Server

Efros, AL

1985-01-01

``Electron-Electron Interactions in Disordered Systems'' deals with the interplay of disorder and the Coulomb interaction. Prominent experts give state-of-the-art reviews of the theoretical and experimental work in this field and make it clear that the interplay of the two effects is essential, especially in low-dimensional systems.

Narrow electron injector for ballistic electron spectroscopy

International Nuclear Information System (INIS)

Kast, M.; Pacher, C.; Strasser, G.; Gornik, E.

2001-01-01

A three-terminal hot electron transistor is used to measure the normal energy distribution of ballistic electrons generated by an electron injector utilizing an improved injector design. A triple barrier resonant tunneling diode with a rectangular transmission function acts as a narrow (1 meV) energy filter. An asymmetric energy distribution with its maximum on the high-energy side with a full width at half maximum of ΔE inj =10 meV is derived. [copyright] 2001 American Institute of Physics

Temperature Dependence of the Spin-Hall Conductivity of a Two-Dimensional Impure Rashba Electron Gas in the Presence of Electron-Phonon and Electron-Electron Interactions

Science.gov (United States)

Yavari, H.; Mokhtari, M.; Bayervand, A.

2015-03-01

Based on Kubo's linear response formalism, temperature dependence of the spin-Hall conductivity of a two-dimensional impure (magnetic and nonmagnetic impurities) Rashba electron gas in the presence of electron-electron and electron-phonon interactions is analyzed theoretically. We will show that the temperature dependence of the spin-Hall conductivity is determined by the relaxation rates due to these interactions. At low temperature, the elastic lifetimes ( and are determined by magnetic and nonmagnetic impurity concentrations which are independent of the temperature, while the inelastic lifetimes ( and related to the electron-electron and electron-phonon interactions, decrease when the temperature increases. We will also show that since the spin-Hall conductivity is sensitive to temperature, we can distinguish the intrinsic and extrinsic contributions.

Analytical local electron-electron interaction model potentials for atoms

International Nuclear Information System (INIS)

Neugebauer, Johannes; Reiher, Markus; Hinze, Juergen

2002-01-01

Analytical local potentials for modeling the electron-electron interaction in an atom reduce significantly the computational effort in electronic structure calculations. The development of such potentials has a long history, but some promising ideas have not yet been taken into account for further improvements. We determine a local electron-electron interaction potential akin to those suggested by Green et al. [Phys. Rev. 184, 1 (1969)], which are widely used in atom-ion scattering calculations, electron-capture processes, and electronic structure calculations. Generalized Yukawa-type model potentials are introduced. This leads, however, to shell-dependent local potentials, because the origin behavior of such potentials is different for different shells as has been explicated analytically [J. Neugebauer, M. Reiher, and J. Hinze, Phys. Rev. A 65, 032518 (2002)]. It is found that the parameters that characterize these local potentials can be interpolated and extrapolated reliably for different nuclear charges and different numbers of electrons. The analytical behavior of the corresponding localized Hartree-Fock potentials at the origin and at long distances is utilized in order to reduce the number of fit parameters. It turns out that the shell-dependent form of Green's potential, which we also derive, yields results of comparable accuracy using only one shell-dependent parameter

Extracting electron backscattering coefficients from backscattered electron micrographs

International Nuclear Information System (INIS)

Zupanic, F.

2010-01-01

Electron backscattering micrographs possess the so-called Z-contrast, carrying information about the chemical compositions of phases present in microstructures. The intensity at a particular point in the backscattered electron micrograph is proportional to the signal detected at a corresponding point in the scan raster, which is, in turn, proportional to the electron backscattering coefficient of a phase at that point. This article introduces a simple method for extracting the electron backscattering coefficients of phases present in the microstructure, from the backscattered electron micrographs. This method is able to convert the micrograph's greyscale to the backscattering-coefficient-scale. The prerequisite involves the known backscattering coefficients for two phases in the micrograph. In this way, backscattering coefficients of other phases can be determined. The method is unable to determine the chemical compositions of phases or the presence of an element only from analysing the backscattered electron micrograph. Nevertheless, this method was found to be very powerful when combined with energy dispersive spectroscopy, and the calculations of backscattering coefficients. - Research Highlights: →A simple method for extracting the electron backscattering coefficients →The prerequisite is known backscattering coefficients for two phases →The information is complementary to the EDS-results. →This method is especially useful when a phase contains a light element (H, Li, Be, and B)

PIC simulation of the electron-ion collision effects on suprathermal electrons

International Nuclear Information System (INIS)

Wu Yanqing; Han Shensheng

2000-01-01

The generation and transportation of suprathermal electrons are important to both traditional ICF scheme and 'Fast Ignition' scheme. The author discusses the effects of electron-ion collision on the generation and transportation of the suprathermal electrons by parametric instability. It indicates that the weak electron-ion term in the PIC simulation results in the enhancement of the collisional absorption and increase of the hot electron temperature and reduction in the maximum electrostatic field amplitude while wave breaking. Therefore the energy and distribution of the suprathermal electrons are changed. They are distributed more close to the phase velocity of the electrostatic wave than the case without electron-ion collision term. The electron-ion collision enhances the self-consistent field and impedes the suprathermal electron transportation. These factors also reduce the suprathermal electron energy. In addition, the authors discuss the effect of initial condition on PIC simulation to ensure that the results are correct

Spin Relaxation in GaAs: Importance of Electron-Electron Interactions

Directory of Open Access Journals (Sweden)

Gionni Marchetti

2014-04-01

Full Text Available We study spin relaxation in n-type bulk GaAs, due to the Dyakonov–Perel mechanism, using ensemble Monte Carlo methods. Our results confirm that spin relaxation time increases with the electronic density in the regime of moderate electronic concentrations and high temperature. We show that the electron-electron scattering in the non-degenerate regime significantly slows down spin relaxation. This result supports predictions by Glazov and Ivchenko. Most importantly, our findings highlight the importance of many-body interactions for spin dynamics: we show that only by properly taking into account electron-electron interactions within the simulations, results for the spin relaxation time—with respect to both electron density and temperature—will reach good quantitative agreement with corresponding experimental data. Our calculations contain no fitting parameters.

Secondary mineralization in carious lesions of human dentin. Electron-probe, electron microscope, and electron diffraction studies

Energy Technology Data Exchange (ETDEWEB)

Ogiwara, H [Tokyo Dental Coll. (Japan)

1975-02-01

Dentinal carious lesions having a remineralized surface layer were studied by means electron-probe microanalysis, electron microscopy, electron diffraction. As the results of electron-probe study, F, Mg, and Na were found to be distributed mainly in the remineralized surface layer and S in the decalcified region where decreases in Ca, P, and Mg concentration were usually observed. The decrease in Mg concentration always started earlier than that of Ca and P concentration. Electron microscope and electron diffraction studies revealed that apatic crystals in the remineralized surface layer were much larger than those in the intact dentin. Although they were less conspicuous, crystals in the decalcified region also were larger than those in the intact region. Dentinal tubules, occluded by many crystals, were frequently seen during the observations. Crystals in the tubules varied in morphology, showing granular, needle, rhomboid, and tabular shapes. By means of electron diffraction, the granular- or needle-shaped crystals were identified as apatite and the rhomboid-shaped crystals as whitlockite. Some of the tabular-shaped crystals appeared to be cotacalcium phosphate.

Electronic components

CERN Document Server

Colwell, Morris A

1976-01-01

Electronic Components provides a basic grounding in the practical aspects of using and selecting electronics components. The book describes the basic requirements needed to start practical work on electronic equipment, resistors and potentiometers, capacitance, and inductors and transformers. The text discusses semiconductor devices such as diodes, thyristors and triacs, transistors and heat sinks, logic and linear integrated circuits (I.C.s) and electromechanical devices. Common abbreviations applied to components are provided. Constructors and electronics engineers will find the book useful

Ion- and electron-acoustic solitons in two-electron temperature space plasmas

International Nuclear Information System (INIS)

Lakhina, G. S.; Kakad, A. P.; Singh, S. V.; Verheest, F.

2008-01-01

Properties of ion- and electron-acoustic solitons are investigated in an unmagnetized multicomponent plasma system consisting of cold and hot electrons and hot ions using the Sagdeev pseudopotential technique. The analysis is based on fluid equations and the Poisson equation. Solitary wave solutions are found when the Mach numbers exceed some critical values. The critical Mach numbers for the ion-acoustic solitons are found to be smaller than those for electron-acoustic solitons for a given set of plasma parameters. The critical Mach numbers of ion-acoustic solitons increase with the increase of hot electron temperature and the decrease of cold electron density. On the other hand, the critical Mach numbers of electron-acoustic solitons increase with the increase of the cold electron density as well as the hot electron temperature. The ion-acoustic solitons have positive potentials for the parameters considered. However, the electron-acoustic solitons have positive or negative potentials depending whether the fractional cold electron density with respect to the ion density is greater or less than a certain critical value. Further, the amplitudes of both the ion- and electron-acoustic solitons increase with the increase of the hot electron temperature. Possible application of this model to electrostatic solitary waves observed on the auroral field lines by the Viking spacecraft is discussed

Establishment of vesicular-arbuscular mycorrhizal fungi and other microorganisms on a beach replenishment site in Florida.

Science.gov (United States)

Sylvia, D M; Will, M E

1988-02-01

Beach replenishment is a widely used method of controlling coastal erosion. To reduce erosional losses from wind, beach grasses are often planted on the replenishment sands. However, there is little information on the microbial populations in this material that may affect plant establishment and growth. The objectives of this research were to document changes in the populations of vesicular-arbuscular mycorrhizal (VAM) fungi and other soil microorganisms in replenishment materials and to determine whether roots of transplanted beach grasses become colonized by beneficial microbes. The study was conducted over a 2-year period on a replenishment project in northeastern Florida. Three sampling locations were established at 1-km intervals along the beach. Each location consisted of three plots: an established dune, replenishment sand planted with Uniola paniculata and Panicum sp., and replenishment sand left unplanted. Fungal and bacterial populations increased rapidly in the rhizosphere of beach grasses in the planted plots. However, no bacteria were recovered that could fix significant amounts of N(2). The VAM fungi established slowly on the transplanted grasses. Even after two growing seasons, levels of root colonization and sporulation were significantly below those found in the established dune. There was a shift in the dominant VAM fungi found in the planted zone with respect to those in the established dunes. The most abundant species recovered from the established dunes were Glomus deserticola, followed by Acaulospora scrobiculata and Scutellospora weresubiae. The VAM fungi that colonized the planted zone most rapidly were Glomus globiferum, followed by G. deserticola and Glomus aggregatum.

Diffusive scattering of electrons by electron holes around injection fronts

Science.gov (United States)

Vasko, I. Y.; Agapitov, O. V.; Mozer, F. S.; Artemyev, A. V.; Krasnoselskikh, V. V.; Bonnell, J. W.

2017-03-01

Van Allen Probes have detected nonlinear electrostatic spikes around injection fronts in the outer radiation belt. These spikes include electron holes (EH), double layers, and more complicated solitary waves. We show that EHs can efficiently scatter electrons due to their substantial transverse electric fields. Although the electron scattering driven by EHs is diffusive, it cannot be evaluated via the standard quasi-linear theory. We derive analytical formulas describing local electron scattering by a single EH and verify them via test particle simulations. We show that the most efficiently scattered are gyroresonant electrons (crossing EH on a time scale comparable to the local electron gyroperiod). We compute bounce-averaged diffusion coefficients and demonstrate their dependence on the EH spatial distribution (latitudinal extent and spatial filling factor) and individual EH parameters (amplitude of electrostatic potential, velocity, and spatial scales). We show that EHs can drive pitch angle scattering of ≲5 keV electrons at rates 10-2-10-4 s-1 and, hence, can contribute to electron losses and conjugated diffuse aurora brightenings. The momentum and pitch angle scattering rates can be comparable, so that EHs can also provide efficient electron heating. The scattering rates driven by EHs at L shells L ˜ 5-8 are comparable to those due to chorus waves and may exceed those due to electron cyclotron harmonics.

Pseudogap in the Eliashberg approach based on electron-phonon and electron-electron-phonon interaction

Energy Technology Data Exchange (ETDEWEB)

Szczesniak, R. [Institute of Physics, Czestochowa University of Technology (Poland); Institute of Physics, Jan Dlugosz University in Czestochowa (Poland); Durajski, A.P.; Duda, A.M. [Institute of Physics, Czestochowa University of Technology (Poland)

2017-04-15

The properties of the superconducting and the anomalous normal state were described by using the Eliashberg method. The pairing mechanism was reproduced with the help of the Hamiltonian, which models the electron-phonon and the electron-electron-phonon interaction (EEPh). The set of the Eliashberg equations, which determines the order parameter function (φ), the wave function renormalization factor (Z), and the energy shift function (χ), was derived. It was proven that for the sufficiently large values of the EEPh potential, the doping dependence of the order parameter (φ/Z) has the analogous course to that observed experimentally in cuprates. The energy gap in the electron density of states is induced by Z and χ - the contribution from φ is negligible. The electron density of states possesses the characteristic asymmetric form and the pseudogap is observed above the critical temperature. (copyright 2017 by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Carbon Nanotube Electron Gun

Science.gov (United States)

Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

2013-01-01

An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

Arbuscular Mycorrhizal Symbiosis with Arundo donax Decreases Root Respiration and Increases Both Photosynthesis and Plant Biomass Accumulation.

Science.gov (United States)

Romero-Munar, Antònia; Del-Saz, Néstor Fernández; Ribas-Carbó, Miquel; Flexas, Jaume; Baraza, Elena; Florez-Sarasa, Igor; Fernie, Alisdair Robert; Gulías, Javier

2017-07-01

The effect of arbuscular mycorrhiza (AM) symbiosis on plant growth is associated with the balance between costs and benefits. A feedback regulation loop has been described in which the higher carbohydrate cost to plants for AM symbiosis is compensated by increases in their photosynthetic rates. Nevertheless, plant carbon balance depends both on photosynthetic carbon uptake and respiratory carbon consumption. The hypothesis behind this research was that the role of respiration in plant growth under AM symbiosis may be as important as that of photosynthesis. This hypothesis was tested in Arundo donax L. plantlets inoculated with Rhizophagus irregularis and Funneliformis mosseae. We tested the effects of AM inoculation on both photosynthetic capacity and in vivo leaf and root respiration. Additionally, analyses of the primary metabolism and ion content were performed in both leaves and roots. AM inoculation increased photosynthesis through increased CO 2 diffusion and electron transport in the chloroplast. Moreover, respiration decreased only in AM roots via the cytochrome oxidase pathway (COP) as measured by the oxygen isotope technique. This decline in the COP can be related to the reduced respiratory metabolism and substrates (sugars and tricarboxylic acid cycle intermediates) observed in roots. © 2017 John Wiley & Sons Ltd.

Molecular electron affinities

International Nuclear Information System (INIS)

Fukuda, E.K.

1983-01-01

Molecular electron affinities have historically been difficult quantities to measure accurately. These difficulties arise from differences in structure between the ion and neutral as well as the existence of excited negative ion states. To circumvent these problems, relative electron affinities were determined in this dissertation by studying equilibrium electron transfer reactions using a pulsed ion cyclotron resonance (ICR) spectrometer. Direct measurement of ion and neutral concentrations for reactions of the general type, A - + B = B - + A, allow calculation of the equilibrium constant and, therefore, the free energy change. The free energy difference is related to the difference in electron affinities between A and B. A relative electron affinity scale covering a range of about 45 kcal/mol was constructed with various substituted p-benzoquinones, nitrobenzenes, anhydrides, and benzophenones. To assign absolute electron affinities, various species with accurately known electron affinities are tied to the scale via ion-cyclotron double resonance bracketing techniques. After the relative scale is anchored to these species with well-known electron affinities, the scale is then used as a check on other electron affinity values as well as generating new electron affinity values. Many discrepancies were found between the electron affinities measured using the ICR technique and previous literature determinations

Nonambipolar electron source

International Nuclear Information System (INIS)

Longmier, B.; Baalrud, S.; Hershkowitz, N.

2006-01-01

A radio frequency (rf) plasma-based electron source that does not rely on electron emission at a cathode surface has been constructed. All of the random electron flux incident on an exit aperture is extracted through an electron sheath resulting in total nonambipolar flow within the device when the ratio of the ion loss area to the electron loss area is approximately equal to the square root of the ratio of the ion mass to the electron mass, and the ion sheath potential drop at the chamber walls is much larger than T e /e. The nonambipolar electron source (NES) has an axisymmetric magnetic field of 100 G at the extraction aperture that results in a uniform plasma potential across the aperture, allowing the extraction of all the incident electron flux without the use of grids. A prototype NES has produced 15 A of continuous electron current, using 15 SCCM (SCCM denotes cubic centimeter per minute at STP) Ar, 1200 W rf power at 13.56 MHz, and 6 times gas utilization. Alternatively 8 A of electron current can be produced, using 3 SCCM Ar at 1200 W rf and 20 times gas utilization. NES could replace hollow cathode electron sources in a wide variety of applications

Electron-plasmon model in the electron liquid theory

Directory of Open Access Journals (Sweden)

M.V.Vavrukh

2005-01-01

Full Text Available Here we propose an accurate approach to the description of the electron liquid model in the electron and plasmon terms. Our ideas in the present paper are close to the conception of the collective variables which was developed in the papers of Bohm and Pines. However we use another body of mathematics in the transition to the expanded space of variable particles and plasmons realized by the transition operator. It is evident that in the Random Phase Approximation (RPA, the model which consists of two interactive subsystems of electrons and plasmons is equivalent to the electron liquid model with Coulomb interaction.

Tratamento radioterápico dos tumores glômicos do osso temporal Radiation therapy for glomus tumors of the temporal bone

Directory of Open Access Journals (Sweden)

Celso Dall'Igna

2005-12-01

tumors has been controversial since its first description. It can be done with surgery, radiotherapy or just expectation. AIM: The objective of this paper was to evaluate the effectiveness and complications of radiotherapy. STUDY DESIGN: clinical with transversal cohort. MATERIAL AND METHOD: It was made a retrospective review in the charts of the patients with glomus jugulare tumors treated with radiotherapy. Disease control was determined by (1 no progression of symptoms or cranial nerve dysfunction or (2 no progression of the lesion in radiological follow-up. It was also evaluated the follow-up period and the sequelae of the treatment. RESULTS: Twelve patients were included, 8 of then women. The follow-up period was from 3 to 35 years, with a media of 11,6 years. The main symptoms were: hearing loss, pulsate tinnitus, dizziness and vertigo. The signs were pulsate retrotympanic mass, facial palsy and cofosis. The tumors were staged using Fisch's classification. The radiotherapy was performed with linear accelerator with dose ranging from 4500-5500 in 4-6 weeks. In the follow-up period were possible to identify sequelaes like dermatitis, meatal stenosis, cofosis and facial palsy. DISCUSSION: The signs and symptoms were the same found in the medical literature. The type and dosages of the radiotherapy were also the same of others reports. All patients had improvement of the symptoms and only one was not considered as having disease controlled. Complications were, in general, minor complications, with exception of the cofosis and facial palsy. CONCLUSION: Radiotherapy is a viable alternative to treatment of these tumors because their good response and low level of complications. It should be considered specially in advanced tumors where a surgical procedure could bring a high level of morbidity.

Polymer electronics

CERN Document Server

Hsin-Fei, Meng

2013-01-01

Polymer semiconductor is the only semiconductor that can be processed in solution. Electronics made by these flexible materials have many advantages such as large-area solution process, low cost, and high performance. Researchers and companies are increasingly dedicating time and money in polymer electronics. This book focuses on the fundamental materials and device physics of polymer electronics. It describes polymer light-emitting diodes, polymer field-effect transistors, organic vertical transistors, polymer solar cells, and many applications based on polymer electronics. The book also disc

A direct electron detector for time-resolved MeV electron microscopy

Energy Technology Data Exchange (ETDEWEB)

Vecchione, T.; Denes, P.; Jobe, R. K.; Johnson, I. J.; Joseph, J. M.; Li, R. K.; Perazzo, A.; Shen, X.; Wang, X. J.; Weathersby, S. P.; Yang, J.; Zhang, D.

2017-03-01

The introduction of direct electron detectors enabled the structural biology revolution of cryogenic electron microscopy. Direct electron detectors are now expected to have a similarly dramatic impact on time-resolved MeV electron microscopy, particularly by enabling both spatial and temporal jitter correction. Here we report on the commissioning of a direct electron detector for time-resolved MeV electron microscopy. The direct electron detector demonstrated MeV single electron sensitivity and is capable of recording megapixel images at 180 Hz. The detector has a 15-bit dynamic range, better than 30-μmμm spatial resolution and less than 20 analogue-to-digital converter count RMS pixel noise. The unique capabilities of the direct electron detector and the data analysis required to take advantage of these capabilities are presented. The technical challenges associated with generating and processing large amounts of data are also discussed.

Coherent Electron Focussing in a Two-Dimensional Electron Gas.

NARCIS (Netherlands)

Houten, H. van; Wees, B.J. van; Mooij, J.E.; Beenakker, C.W.J.; Williamson, J.G.; Foxon, C.T.

1988-01-01

The first experimental realization of ballistic point contacts in a two-dimensional electron gas for the study of transverse electron focussing by a magnetic field is reported. Multiple peaks associated with skipping orbits of electrons reflected specularly by the channel boundary are observed. At

A study on the secondary electrons in a clinical electron beam

International Nuclear Information System (INIS)

Krithivas, G.; Rao, S.N.

1989-01-01

The central axis dose of a 12 MeV clinical electron beam is investigated in terms of an axial component due to primary electrons in the central ray and a lateral component due to secondary electrons originating from multiple scattering of electrons in the off-axis rays. To this effect secondary electron fluence measurements in a polystyrene medium irradiated with a collimated beam are made with a sensitive diode detector. This leads to a construction of secondary electron depth-dose profiles for beam sizes of diameters ranging from 1.7 to 17.4 cm. The results indicate that the lateral electrons account for 25% of the dose in the therapeutic region. For these electrons, the depth of dose maximum is correlated with diffusion depth and maximum lateral excursion in the medium. Dose component due to backscatter electrons at depths is also investigated using a thin-window parallel-plate ion chamber. The role of lateral and backscatter electrons in characterising central axis per cent depth-dose is discussed. (author)

Phosphorus uptake of an arbuscular mycorrhizal fungus is not effected by the biocontrol bacterium ¤Burkholderia cepacia¤

DEFF Research Database (Denmark)

Ravnskov, S.; Larsen, J.; Jakobsen, I.

2002-01-01

The biocontrol bacterium Burkholderia cepacia is known to suppress a broad range of root pathogenic fungi, while its impact on other beneficial non-target organisms such as arbuscular mycorrhizal (AM) fungi is unknown. Direct interactions between five B. cepacia strains and the AM fungus, Glomus ...

Assessing hydroaeroponic culture for the tripartite symbiosis of ...

African Journals Online (AJOL)

It is argued that the later will probably be a valuable tool for scrutinizing the interactions among the three symbionts, as well as plant physiology, and nutrient partitioning within the symbiotic system. Key words: Acaulospora mellea, arbuscular mycorrhizal, Bradyrhizobium, Gigaspora rosea, Glomus intraradices, mungbean, ...

Effects of arbuscular mycorrhizal inoculation on cadmium accumulation by different tobacco (Nicotiana tabacum L.) types

Czech Academy of Sciences Publication Activity Database

Janoušková, Martina; Vosátka, Miroslav; Rossi, L.; Lugon-Moulin, M.

2007-01-01

Roč. 35, č. 3 (2007), s. 502-510 ISSN 0929-1393 R&D Projects: GA AV ČR KSK6005114 Institutional research plan: CEZ:AV0Z60050516 Keywords : agriculture * Glomus * heavy metals Subject RIV: EF - Botanics Impact factor: 1.810, year: 2007

Influence of mycorrhizal fungi on survival of salmonella and E.coli O157:H7 in soil and translocation into allium porrum roots and stem

Science.gov (United States)

Modern agriculture disrupts the natural symbiotic relationship arbuscular mycorrhizal (AM) fungi have with most vegetable plants, which may affect translocation of human pathogens into the plant. Five-month-old Allium porrum (leek) plants (with or without AMF [Glomus intraradices]) were used as a m...

Comparison of communities of arbuscular mycorrhizal fungi in roots of two Viola species

DEFF Research Database (Denmark)

Opik, M; Moora, Mari; Liira, Jaan

2006-01-01

The composition of arbuscular mycorrhizal (AM) fungal communities in roots of rare Viola elatior and common V. mirabilis was investigated using PCR with primers specific for Glomus and common was investigated using PCR with primers specific for group A, followed by single-stranded conformation...

Production of cell wall enzymes in pepper seedlings, inoculated with ...

African Journals Online (AJOL)

Pepper seedlings inoculated with arbuscular mycorrhizal AM fungus, Glomus etunicatum, produced cellulase, polygal-acturonase and pectin methylestrase enzymes. The activities of the enzymes increased as the pepper seedlings matured in age, showing that the activity of the enzymes in the seedlings was age mediated.

Role of bioinoculants in development of salt-tolerance of Vicia faba ...

African Journals Online (AJOL)

Through biological inoculation technology, the bacterial-mycorrhizal-legume tripartite symbiosis in saline conditions was documented and the effects of dual inoculation with Azospirillum brasilense (NFB) and Arbuscular mycorrhizal (Am) fungus Glomus clarum on the host plants (Vicia faba) in pot cultures were investigated ...

Vesicular-arbuscular mycorrhizae in jojoba and mariola

Energy Technology Data Exchange (ETDEWEB)

Bloss, H E

1975-01-01

Glomus fasculatus was isolated from soil and roots of the indigenous desert plants Parthenium incanum and Simmondsia chinensis, possible sources of rubber and a waxy oil, respectively. It is suggested that inoculation of these plants with mycorrhizal G. spp. could enhance their productivity under cultivation.

Browse Title Index

African Journals Online (AJOL)

Items 251 - 300 of 425 ... Vol 48 (2017), Growth and yield of cassava as influenced by maize ... Vol 40, No 1-2 (2009), Influence of two glomus species on the fertilizer efficiency of ... Vol 45, No 2 (2014), Market participation among rice producing ...

Interaction of arbuscular mycorrhizal fungi and rhizobia: Effects on flax yield in spoil-bank clay

Czech Academy of Sciences Publication Activity Database

Rydlová, Jana; Püschel, David; Sudová, Radka; Gryndler, M.; Mikanová, O.; Vosátka, Miroslav

2011-01-01

Roč. 174, č. 1 (2011), s. 128-134 ISSN 1436-8730 R&D Projects: GA MŠk 1M0571 Institutional research plan: CEZ:AV0Z60050516 Keywords : Linum usitatissimum * Glomus * Sinorhizobium Subject RIV: EF - Botanics Impact factor: 1.596, year: 2011

Electronics for dummies

CERN Document Server

Shamieh

2015-01-01

Explore the basic concepts of electronics, build your electronics workbench, and begin creating fun electronics projects right away! Electronics For Dummies, 3rd Edition is your guide to the world of electronics. Spanning circuitry, wiring, robotics, transmitters, amplifiers, and more, this book demystifies electricity basics and beyond. The third edition offers new content revised to reflect the latest advancements in the electronics field, and it offers full color project examples to spark your creativity and inspire you to put your new skills to use! Packed with projects that can be comple

Electron holography

CERN Document Server

Tonomura, Akira

1993-01-01

Holography was devised for breaking through the resolution limit of electron microscopes The advent of a "coherent" field emission electron beam has enabled the use of Electron Holography in various areas of magnetic domain structures observation, fluxon observation in superconductors, and fundamental experiments in physics which have been inaccessible using other techniques After examining the fundamentals of electron holography and its applications to the afore mentioned fields, a detailed discussion of the Aharonov-Bohm effect and the related experiments is presented Many photographs and illustrations are included to elucidate the text

Comprehensive analysis of electron correlations in three-electron atoms

International Nuclear Information System (INIS)

Morishita, T.; Lin, C.D.

1999-01-01

We study the electron correlations in singly, doubly, and triply excited states of a three-electron atom. While electron correlation in general is weak for singly excited states, correlation plays major roles in determining the characteristics of doubly and triply excited states. Using the adiabatic approximation in hyperspherical coordinates, we show that the distinction between singly, doubly, and triply excited states is determined by the radial correlations, while finer distinctions within doubly or triply excited states lie in the angular correlations. Partial projections of the body-fixed frame wave functions are used to demonstrate the characteristic nodal surfaces which provide clues to the energy ordering of the states. We show that doubly excited states of a three-electron atom exhibit correlations that are similar to the doubly excited states of a two-electron atom. For the triply excited states, we show that the motion of the three electrons resemble approximately that of a symmetric top. copyright 1999 The American Physical Society

Advanced electron beam techniques

International Nuclear Information System (INIS)

Hirotsu, Yoshihiko; Yoshida, Yoichi

2007-01-01

After 100 years from the time of discovery of electron, we now have many applications of electron beam in science and technology. In this report, we review two important applications of electron beam: electron microscopy and pulsed-electron beam. Advanced electron microscopy techniques to investigate atomic and electronic structures, and pulsed-electron beam for investigating time-resolved structural change are described. (author)

Effects of electron-electron interactions on electronic transport in disordered systems

International Nuclear Information System (INIS)

Foley, Simon Timothy

2002-01-01

This thesis is concerned with the role of electron-electron interactions on electronic transport in disordered systems. We first consider a novel non-linear sigma model in order to microscopically treat the effects of disorder and electronic interaction. We successfully reproduce the perturbative results for the zero-bias anomaly and the interaction correction to the conductivity in a weakly disordered system, and discuss possible directions for future work. Secondly we consider the fluctuations of the dephasing rate for a closed diffusive and quantum dot system. Using the Keldysh technique we derive an expression for the inelastic scattering rate with which we self-consistently obtain the fluctuations in the dephasing rate. For the diffusive regime we find the relative fluctuations is given by F ∼ (L φ /L) 2 /g 2 , where g is the dimensionless conductance, L φ is the dephasing length and L is the sample size. For the quantum dot regime we find a perturbative divergence due to the presence of the zero mode. By mapping divergent diagrams to those for the two-level correlation function, we conjecture the existence of an exact relation between the two. Finally we discuss the consequences of this relation. (author)

Characteristics of trapped electrons and electron traps in single crystals

International Nuclear Information System (INIS)

Budzinski, E.E.; Potter, W.R.; Potienko, G.; Box, H.C.

1979-01-01

Two additional carbohydrates are reported whose crystal structures trap electrons intermolecularly in single crystals x irradiated at low temperature, namely sucrose and rhamnose. Five carbohydrate and polyhydroxy compounds are now known which exhibit this phenomenon. The following characteristics of the phenomenon were investigated: (1) the hyperfine couplings of the electron with protons of the polarized hydroxy groups forming the trap; (2) the distances between these protons and the trapped electron; (3) the spin density of the electron at the protons and (4) the relative stabilities of the electron trapped in various crystal structures

Electron-electron scattering in linear transport in two-dimensional systems

DEFF Research Database (Denmark)

Hu, Ben Yu-Kuang; Flensberg, Karsten

1996-01-01

We describe a method for numerically incorporating electron-electron scattering in quantum wells for small deviations of the distribution function from equilibrium, within the framework of the Boltzmann equation. For a given temperature T and density n, a symmetric matrix needs to be evaluated only...... once, and henceforth it can be used to describe electron-electron scattering in any Boltzmann equation linear-response calculation for that particular T and n. Using this method, we calculate the distribution function and mobility for electrons in a quantum well, including full finite...

Terahertz Plasma Waves in Two Dimensional Quantum Electron Gas with Electron Scattering

International Nuclear Information System (INIS)

Zhang Liping

2015-01-01

We investigate the Terahertz (THz) plasma waves in a two-dimensional (2D) electron gas in a nanometer field effect transistor (FET) with quantum effects, the electron scattering, the thermal motion of electrons and electron exchange-correlation. We find that, while the electron scattering, the wave number along y direction and the electron exchange-correlation suppress the radiation power, but the thermal motion of electrons and the quantum effects can amplify the radiation power. The radiation frequency decreases with electron exchange-correlation contributions, but increases with quantum effects, the wave number along y direction and thermal motion of electrons. It is worth mentioning that the electron scattering has scarce influence on the radiation frequency. These properties could be of great help to the realization of practical THz plasma oscillations in nanometer FET. (paper)

Oblique electron cyclotron emission for electron distribution studies (invited)

International Nuclear Information System (INIS)

Preische, S.; Efthimion, P.C.; Kaye, S.M.

1997-01-01

Electron cyclotron emission (ECE) at an oblique angle to the magnetic field provides a means of probing the electron distribution function both in energy and physical space through changes in and constraints on the relativistic electron cyclotron resonance condition. Diagnostics based on this Doppler shifted resonance are able to study a variety of electron distributions through changes in the location of the resonance in physical or energy space accomplished by changes in the viewing angle and frequency, and the magnetic field. For the case of observation across a changing magnetic field, such as across the tokamak midplane, the constraint on the resonance condition for real solutions to the dispersion relation can constrain the physical location of optically thin emission. A new Oblique ECE diagnostic was installed and operated on the PBX-M tokamak for the study of energetic electrons during lower hybrid current drive. It has a view 33 degree with respect to perpendicular in the tokamak midplane, receives second harmonic X-mode emission, and is constrained to receive single pass emission by SiC viewing dumps on the tokamak walls. Spatial localization of optically thin emission from superthermal electrons (50 endash 100 keV) was obtained by observation of emission upshifted from a thermal cyclotron harmonic. The localized measurements of the electron energy distribution and the superthermal density profile made by this diagnostic demonstrate its potential to study the spatial transport of energetic electrons on fast magnetohydrodynamic time scales or anomalous diffusion time scales. Oblique ECE can also be used to study electron distributions that may have a slight deviation from a Maxwellian by localizing the emission in energy space. (Abstract Truncated)

Electron microscopy of boron carbide before and after electron irradiation

International Nuclear Information System (INIS)

Stoto, T.; Zuppiroli, L.; Beauvy, M.; Athanassiadis, T.

1984-06-01

The microstructure of boron carbide has been studied by electron microscopy and related to the composition of the material. After electron irradiations in an usual transmission electron microscope and in a high voltage electron microscope at different temperatures and fluxes no change of these microstructures have been observed but a sputtering of the surface of the samples, which has been studied quantitatively [fr

Electron Cyclotron Resonances in Electron Cloud Dynamics

International Nuclear Information System (INIS)

Celata, Christine; Celata, C.M.; Furman, Miguel A.; Vay, J.-L.; Yu, Jennifer W.

2008-01-01

We report a previously unknown resonance for electron cloud dynamics. The 2D simulation code 'POSINST' was used to study the electron cloud buildup at different z positions in the International Linear Collider positron damping ring wiggler. An electron equilibrium density enhancement of up to a factor of 3 was found at magnetic field values for which the bunch frequency is an integral multiple of the electron cyclotron frequency. At low magnetic fields the effects of the resonance are prominent, but when B exceeds ∼(2 pi mec/(elb)), with lb = bunch length, effects of the resonance disappear. Thus short bunches and low B fields are required for observing the effect. The reason for the B field dependence, an explanation of the dynamics, and the results of the 2D simulations and of a single-particle tracking code used to elucidate details of the dynamics are discussed

Role of electron-electron interactions in the RKKY theory of magnetism

International Nuclear Information System (INIS)

Cooke, J.F.

1978-10-01

The theory of magnetism in heavy rare earth metals is based on the RKKY theory. In this formalism the indirect exchange interaction between the local 4f spins is mediated by the conduction electrons. When carried to second order in the 4f-conduction electron interaction, traditional perturbation theory leads to a Heisenberg-like interaction between the local spins which depends on the electronic energy bands and 4f-conduction electron exchange matrix elements. This derivation neglects the detailed behavior of electron-electron interaction within the conduction band, which is known to be important in metallic systems. By using an equation of motion method, an expression for the inelastic neutron scattering cross-section has been derived which includes, in an approximate way, this electron-electron interaction. The results of this calculation indicate that spin-wave peaks can be broadened and shifted if the spin-wave band lies near the conduction electron Stoner continuum. The origin of this effect is similar to that found in itinerant electron systems where the spin-wave band actually intersects the Stoner continuum, resulting in the disappearance of the spin-wave mode

Role of electron-electron interactions in the RKKY theory of magnetism

International Nuclear Information System (INIS)

Cooke, J.F.

1979-01-01

The theory of magnetism in heavy rare earth metals is based on the RKKY theory. In this formalism the indirect exchange interaction between the local 4f spins is mediated by the conduction electrons. When carried to second order in the 4f-conduction electron interaction, traditional pertubation theory leads to a Heisenberg-like interaction between the local spins which depends on the electronic energy bands and 4f-conduction electron exchange matrix elements. This derivation neglects the detailed behavior of electron-electron interaction within the conduction band, which is known to be important in metallic systems. By using an equation of motion method, an expression for the inelastic neutron scattering cross-section has been derived which includes, in an approximate way, this electron-electron interaction. The results of this calculation indicate that spin-wave peaks can be broadened and shifted if the spin-wave band lies near the conduction electron Stoner continuum. The origin of this effect is similar to that found in itinerant electron systems where the spin-wave band actually intersects the Stoner continuum, resulting in the disappearance of the spin-wave mode

Electron acoustic solitary waves in unmagnetized two electron population dense plasmas

International Nuclear Information System (INIS)

Mahmood, S.; Masood, W.

2008-01-01

The electron acoustic solitary waves are studied in unmagnetized two population electron quantum plasmas. The quantum hydrodynamic model is employed with the Sagdeev potential approach to describe the arbitrary amplitude electron acoustic waves in a two electron population dense Fermi plasma. It is found that hot electron density hump structures are formed in the subsonic region in such type of quantum plasmas. The wave amplitude as well as the width of the soliton are increased with the increase of percentage presence of cold (thinly populated) electrons in a multicomponent quantum plasma. It is found that an increase in quantum diffraction parameter broadens the nonlinear structure. Furthermore, the amplitude of the nonlinear electron acoustic wave is found to increase with the decrease in Mach number. The numerical results are also presented to understand the formation of solitons in two electron population Fermi plasmas.

Advances in imaging and electron physics the scanning transmission electron microscope

CERN Document Server

Hawkes, Peter W

2009-01-01

Advances in Imaging and Electron Physics merges two long-running serials--Advances in Electronics and Electron Physics and Advances in Optical and Electron Microscopy. This series features extended articles on the physics of electron devices (especially semiconductor devices), particle optics at high and low energies, microlithography, image science and digital image processing, electromagnetic wave propagation, electron microscopy, and the computing methods used in all these domains.  This particular volume presents several timely articles on the scanning transmission electron microscope. Updated with contributions from leading international scholars and industry experts Discusses hot topic areas and presents current and future research trends Provides an invaluable reference and guide for physicists, engineers and mathematicians.

Attractive electron correlation in wide band gap semiconductors by electron-photon interaction

International Nuclear Information System (INIS)

Takeda, Hiroyuki; Yoshino, Katsumi

2004-01-01

We theoretically demonstrate attractive electron correlation in wide band gap semiconductors by electron-photon interaction. At low temperature, wavevectors of electromagnetic waves absorbed in wide band gap semiconductors cannot be neglected for wavevectors of electron waves; that is, electromagnetic waves affect the movements of electrons. In particular, attractive interaction occurs between two electrons when one electron changes from a valence band to a conduction band and the other electron changes from a conduction band to a valence band

Electronic Publishing or Electronic Information Handling?

Science.gov (United States)

Heck, A.

The current dramatic evolution in information technology is bringing major modifications in the way scientists communicate. The concept of 'electronic publishing' is too restrictive and has often different, sometimes conflicting, interpretations. It is thus giving way to the broader notion of 'electronic information handling' encompassing the diverse types of information, the different media, as well as the various communication methodologies and technologies. New problems and challenges result also from this new information culture, especially on legal, ethical, and educational grounds. The procedures for validating 'published material' and for evaluating scientific activities will have to be adjusted too. 'Fluid' information is becoming a common concept. Electronic publishing cannot be conceived without link to knowledge bases nor without intelligent information retrieval tools.

Theoretical study of the interplay of electron-electron interaction and disorder

International Nuclear Information System (INIS)

Brezini, A.; Behilil, S.

1988-10-01

A disordered Hubbard model with diagonal disorder is used to investigate the electron localization effects associated with both disorder and electron-electron interaction. Extensive results are reported on the ground state properties and compared to other theories. Two regimes have been found: when the electron-electron interaction u is greater than the disorder parameter w and when u < w. (author). 18 refs, 4 figs

Defining Electron Bifurcation in the Electron-Transferring Flavoprotein Family.

Science.gov (United States)

Garcia Costas, Amaya M; Poudel, Saroj; Miller, Anne-Frances; Schut, Gerrit J; Ledbetter, Rhesa N; Fixen, Kathryn R; Seefeldt, Lance C; Adams, Michael W W; Harwood, Caroline S; Boyd, Eric S; Peters, John W

2017-11-01

Electron bifurcation is the coupling of exergonic and endergonic redox reactions to simultaneously generate (or utilize) low- and high-potential electrons. It is the third recognized form of energy conservation in biology and was recently described for select electron-transferring flavoproteins (Etfs). Etfs are flavin-containing heterodimers best known for donating electrons derived from fatty acid and amino acid oxidation to an electron transfer respiratory chain via Etf-quinone oxidoreductase. Canonical examples contain a flavin adenine dinucleotide (FAD) that is involved in electron transfer, as well as a non-redox-active AMP. However, Etfs demonstrated to bifurcate electrons contain a second FAD in place of the AMP. To expand our understanding of the functional variety and metabolic significance of Etfs and to identify amino acid sequence motifs that potentially enable electron bifurcation, we compiled 1,314 Etf protein sequences from genome sequence databases and subjected them to informatic and structural analyses. Etfs were identified in diverse archaea and bacteria, and they clustered into five distinct well-supported groups, based on their amino acid sequences. Gene neighborhood analyses indicated that these Etf group designations largely correspond to putative differences in functionality. Etfs with the demonstrated ability to bifurcate were found to form one group, suggesting that distinct conserved amino acid sequence motifs enable this capability. Indeed, structural modeling and sequence alignments revealed that identifying residues occur in the NADH- and FAD-binding regions of bifurcating Etfs. Collectively, a new classification scheme for Etf proteins that delineates putative bifurcating versus nonbifurcating members is presented and suggests that Etf-mediated bifurcation is associated with surprisingly diverse enzymes. IMPORTANCE Electron bifurcation has recently been recognized as an electron transfer mechanism used by microorganisms to maximize

Effects of electron-electron interactions on the electron distribution function of a plasma in the presence of an external electric field

International Nuclear Information System (INIS)

Molinari, V.G.; Pizzio, F.; Spiga, G.

1979-01-01

The electron distribution function, the electron temperature and some transport parameters (electrical conductivity and energy flow coefficient) are obtained starting from the nonlinear Boltzmann equation for a plasma under the action of an external electric field. The Fokker-Planck approximation is used for electron-electron and electron-ion interactions. The effects of electron-electron collisions are studied for different values of collision frequencies and electric field. (author)

Electron-excited molecule interactions

International Nuclear Information System (INIS)

Christophorou, L.G.; Tennessee Univ., Knoxville, TN

1991-01-01

In this paper the limited but significant knowledge to date on electron scattering from vibrationally/rotationally excited molecules and electron scattering from and electron impact ionization of electronically excited molecules is briefly summarized and discussed. The profound effects of the internal energy content of a molecule on its electron attachment properties are highlighted focusing in particular on electron attachment to vibrationally/rotationally and to electronically excited molecules. The limited knowledge to date on electron-excited molecule interactions clearly shows that the cross sections for certain electron-molecule collision processes can be very different from those involving ground state molecules. For example, optically enhanced electron attachment studies have shown that electron attachment to electronically excited molecules can occur with cross sections 10 6 to 10 7 times larger compared to ground state molecules. The study of electron-excited molecule interactions offers many experimental and theoretical challenges and opportunities and is both of fundamental and technological significance. 54 refs., 15 figs

Effects of Arbuscular Mycorrhizal Symbiosis (Glomus intraradice on Egyptian Broomrape (Orobanche aegyptiaca. Pers in Cultivated Tomato (Lycopersicon esculentum Mill.

Directory of Open Access Journals (Sweden)

mojtaba zafarian

2017-03-01

Full Text Available Introduction: Mycorrhizal symbiosis is one of the most popular and highest symbiotic relationship in plant kingdom. Most plants (about 80% of vascular plant species have at least one type of mycorrhiza. Arbuscular mycorrhizal fungies are the most important endomycorhiza fungi that play an important role in agriculture. Materials and Methods: In order to evaluate the effect of arbuscular mycorrhizal (Glomus intraradice symbiosis to control Egyptian Broomrape (Orobanche aegyptiaca. Pers in cultivated tomato (Lycopersicon esculentum Mill. growth, a glasshouse experiment was conducted in CRD design with four replications in Shahrekord university in summer 2014. Treatments consisted of four arbuscular mycorrhizal levels (50, 100, 150 and 200 kg ha-1 and two control treatments of weed free and weed infested treatments, respectively. In this experiment, seeds of speedy tomato cultivar planted in the bed that consisted of coco peat and peat moss were transplanted to the pots. Pots with diameter 20 and height 15 cm were filled with soil in the ratio 4: 1: 1 manure, sand and clay respectively and with 50 mg of Orobanche seeds that were collected in the previous year. It should be noted that the soil combination was disinfected at a temperature of 80OC for 72 h to reduce the potential effects of soil microbial population in reducing Orobanche germination. The fungal inoculation, containing sandy soil fungal body parts and organs fungal root was then added to each pot. Fungi strain was provided from the plant protection clinic located in Hamadan. Also, nutrition of tomato after being transplanted to pots was carried out with foliar application of complete micronutrient of 20-20-20 every 7 days under glasshouse condition. At the end of the season, were measured number of stems, number of nodules on the roots of tomato, time of emergence of orobanche flower on the soil surface, orobanche dry weight and tomato root and shoot dry weight. Statistical analysis of

Seeing with electrons

International Nuclear Information System (INIS)

Nellist, P.

2006-01-01

Commercially available lens correctors are extending the reach of electron microscopes to unprecedented atomic scales, as Peter Nellist describes. The electron microscope was invented in 1933 and is based on the principle that electrons have a wavelength that is inversely proportional to their momentum. There are two basic types: transmission electron microscopes and scanning electron microscopes, plus a hybrid of the two. The lenses in an electron microscope are provided by electromagnetic fields, but they suffer from spherical aberration. The addition of octupole and quadrupole corrector fields has improved the resolution of the electron microscope to better than 0.1 nm in the last decade. The next step is to correct for chromatic aberration, after which the resolution of the microscope will probably be limited by the size of the atom itself. (U.K.)

Introduction to electronics

CERN Multimedia

CERN. Geneva

2005-01-01

Electronics in HEP experiments: specificities and evolution The Art of Electronics: is there something beyond Ohm's law? Basic building blocks of Analog electronics: quickly understanding a schematic Charge preamps, current preamps and future preamps, shaping and the rest Electronics noise: fundamental and practical Evolution of technology: ASICs, FPGAs...

Multiple electron generation in a sea of electronic states

Science.gov (United States)

Witzel, Wayne; Shabaev, Andrew; Efros, Alexander; Hellberg, Carl; Verne, Jacobs

2009-03-01

In traditional bulk semiconductor photovoltaics (PVs), each photon may excite a single electron-hole, wasting excess energy beyond the band-gap as heat. In nanocrystals, multiple excitons can be generated from a single photon, enhancing the PV current. Multiple electron generation (MEG) may result from Coulombic interactions of the confined electrons. Previous investigations have been based on incomplete or over-simplified electronic-state representations. We present results of quantum simulations that include hundreds of thousands of configuration states and show how the complex dynamics, even in a closed electronic system, yields a saturated MEG effect on a femtosecond timescale. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Electron collision cross sections and electron swarm parameters for gas molecules

International Nuclear Information System (INIS)

Hayashi, Makoto

1986-01-01

Elastic and inelastic electron collision cross sections for molecules which interest in radiation research have been determined from available electron beam and electron swarm data by utilizing the Boltzmann equation and Monte Carlo simulation method. Electron drift velocity data which interest in radiation Pysics have been discussed and some calculated results of electron drift velocity data for CF 4 and CF 4 -inert gases mixtures will be presented. (author)

Early-delayed radiation rhombencephalopathy

International Nuclear Information System (INIS)

Nightingale, S.; Dawes, P.J.D.K.; Cartlidge, N.E.F.; Newcastle upon Tyne Univ.

1982-01-01

A 37-year-old woman developed an early-delayed rhombencephalopathy 7 weeks after completing a course of radiotherapy to a glomus jugulare tumour. The clinical features, comprising nystagmus, skew strabismus, unilateral facial weakness, dysarthria and ataxia, are compared with four previously reported patients with this syndrome. (author)

Neem ( Azadirachta indica a. juss) seedling growth as influenced by ...

African Journals Online (AJOL)

The effect of Arbuscular mycorrhizal fungus (AMF), specifically, Glomus moseae and cow dung on the growth of Neem (Azadiracchta indica, A. Juss) seedlings was investigated at the forestry quarters, Lagos Street, Maiduguri, Borno State, Nigeria. The study included three treatments: the cow dung, mycorrhizal treatments ...

Efficacité des champignons mycorhiziens contre les nématodes ...

African Journals Online (AJOL)

SARAH

30 mai 2015 ... Mots clés : Glomus sp., Lycopersicon esculentum, lutte biologique, Meloidogyne spp. Effectiveness of the arbuscular mycorrhizal fungi on the parasitic nematodes of tomato in Togo. ABSTRACT. Objectives : To find alternatives to the synthetic pesticides used against nematodes the present work aimed at.

Responses of soilless grown tomato plants to arbuscular ...

African Journals Online (AJOL)

STORAGESEVER

2008-10-20

Oct 20, 2008 ... Full Length Research Paper. Responses of soilless grown tomato plants to arbuscular mycorrhizal fungal (Glomus fasciculatum) colonization in re-cycling and open systems. H. Yildiz Dasgan1*, Sebnem Kusvuran1 and Ibrahim Ortas2. 1Cukurova University, Faculty of Agriculture, Department of Horticulture ...

Electronic payment systems

OpenAIRE

Mláka, Michal

2010-01-01

This bachelor thesis analysis issue of electronic payment systems. It discusses their use for payments on the internet and sending funds via e-mail. The first part is devoted to the theoretical definition and legislation of the issuance of electronic money and activities of electronic money institutions. The main part of the work clearly focuses on the use of e-wallets, which is an integral part of electronic payment systems. E-wallet of electronic payment system Moneybookers is considered as...

Wigner-like crystallization of Anderson-localized electron systems with low electron densities

CERN Document Server

Slutskin, A A; Pepper, M

2002-01-01

We consider an electron system under conditions of strong Anderson localization, taking into account interelectron long-range Coulomb repulsion. We establish that at sufficiently low electron densities and sufficiently low temperatures the Coulomb electron interaction brings about ordering of the Anderson-localized electrons into a structure that is close to an ideal (Wigner) crystal lattice, provided the dimension of the system is > 1. This Anderson-Wigner glass (AWG) is a new macroscopic electron state that, on the one hand, is beyond the conventional Fermi glass concept, and on the other hand, qualitatively differs from the known 'plain' Wigner glass (inherent in self-localized electron systems) in that the random slight electron displacements from the ideal crystal sites essentially depend on the electron density. With increasing electron density the AWG is found to turn into the plain Wigner glass or Fermi glass, depending on the width of the random spread of the electron levels. It is shown that the res...

Excess electrons in methanol clusters: Beyond the one-electron picture

Science.gov (United States)

Pohl, Gábor; Mones, Letif; Turi, László

2016-10-01

We performed a series of comparative quantum chemical calculations on various size negatively charged methanol clusters, ("separators=" CH 3 OH ) n - . The clusters are examined in their optimized geometries (n = 2-4), and in geometries taken from mixed quantum-classical molecular dynamics simulations at finite temperature (n = 2-128). These latter structures model potential electron binding sites in methanol clusters and in bulk methanol. In particular, we compute the vertical detachment energy (VDE) of an excess electron from increasing size methanol cluster anions using quantum chemical computations at various levels of theory including a one-electron pseudopotential model, several density functional theory (DFT) based methods, MP2 and coupled-cluster CCSD(T) calculations. The results suggest that at least four methanol molecules are needed to bind an excess electron on a hydrogen bonded methanol chain in a dipole bound state. Larger methanol clusters are able to form stronger interactions with an excess electron. The two simulated excess electron binding motifs in methanol clusters, interior and surface states, correlate well with distinct, experimentally found VDE tendencies with size. Interior states in a solvent cavity are stabilized significantly stronger than electron states on cluster surfaces. Although we find that all the examined quantum chemistry methods more or less overestimate the strength of the experimental excess electron stabilization, MP2, LC-BLYP, and BHandHLYP methods with diffuse basis sets provide a significantly better estimate of the VDE than traditional DFT methods (BLYP, B3LYP, X3LYP, PBE0). A comparison to the better performing many electron methods indicates that the examined one-electron pseudopotential can be reasonably used in simulations for systems of larger size.

Electron dose rate and photon contamination in electron arc therapy

International Nuclear Information System (INIS)

Pla, M.; Podgorsak, E.B.; Pla, C.

1989-01-01

The electron dose rate at the depth of dose maximum dmax and the photon contamination are discussed as a function of several parameters of the rotational electron beam. A pseudoarc technique with an angular increment of 10 degrees and a constant number of monitor units per each stationary electron field was used in our experiments. The electron dose rate is defined as the electron dose at a given point in phantom divided by the number of monitor units given for any one stationary electron beam. For a given depth of isocenter di the electron dose rates at dmax are linearly dependent on the nominal field width w, while for a given w the dose rates are inversely proportional to di. The dose rates for rotational electron beams with different di are related through the inverse square law provided that the two beams have (di,w) combinations which give the same characteristic angle beta. The photon dose at the isocenter depends on the arc angle alpha, field width w, and isocenter depth di. For constant w and di the photon dose at isocenter is proportional to alpha, for constant alpha and w it is proportional to di, and for constant alpha and di it is inversely proportional to w. The w and di dependence implies that for the same alpha the photon dose at the isocenter is inversely proportional to the electron dose rate at dmax

Glomangiomyoma of the neck in a child in Nepal: a rare case report and literature review

Directory of Open Access Journals (Sweden)

Bishow Tulachan

2017-11-01

Full Text Available Abstract Background Glomangiomyoma is a rare histological variant of glomus tumour. Clinically, it mimicks as a haemangioma and is challenging to diagnose. Its occurrence in the neck of a child has not been previously described. Case presentation A 3 year old girl presented with the complaints of painless progressive neck swelling in the right side for one and half year. Sonography, computed tomography (CT, magnetic resonance imaging (MRI, CT neck angiography and fine needle aspiration cytology (FNAC were suggestive of vacular malformation i.e. giant haemangioma or arteriovenous malformation. The mass was removed in toto under general anaesthesia without postoperative complications. The histopathology confirmed it to be glomangiomyoma with haemangiopericytoma like features. Conclusion It’s an extremely rare variant of glomus tumour and may be the first report of a glomangiomyoma in the neck of a child. Despite a rare entity, it should be borne in mind during differential diagnosis.

Power Electronics

DEFF Research Database (Denmark)

Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

2008-01-01

is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...... emerging renewable energy sources, wind energy, which by means of power electronics are changing from being a minor energy source to be acting as an important power source in the energy system. Power electronics is the enabling technology and the presentation will cover the development in wind turbine...... technology from kW to MW, discuss which power electronic solutions are most feasible and used today....

Electron Emission from Ultra-Large Area MOS Electron Emitters

DEFF Research Database (Denmark)

Thomsen, Lasse Bjørchmar; Nielsen, Gunver; Vendelbo, Søren Bastholm

2009-01-01

Ultralarge metal-oxide-semiconductor (MOS) devices with an active oxide area of 1 cm2 have been fabricated for use as electron emitters. The MOS structures consist of a Si substrate, a SiO2 tunnel barrier (~5 nm), a Ti wetting layer (3–10 Å), and a Au top layer (5–60 nm). Electron emission from...... layer is varied from 3 to 10 Å which changes the emission efficiency by more than one order of magnitude. The apparent mean free path of ~5 eV electrons in Au is found to be 52 Å. Deposition of Cs on the Au film increased the electron emission efficiency to 4.3% at 4 V by lowering the work function....... Electron emission under high pressures (up to 2 bars) of Ar was observed. ©2009 American Vacuum Society...

Comparative analysis of the terms "electronic commerce" and "electronic business"

OpenAIRE

Kavaliauskienė, Virginija; Šarapovas, Tadas

2002-01-01

Establishing the terms that clearly and consistently describe growing and dynamic networked economy is a critical first step toward further analysis and evaluation of electronic commerce and electronic business processes. Electronic commerce is making an impact on the ways that purchasing activities are being conducted. Much of the early literature on this subject was very speculative. However, the growth of e-commerce has enabled more observations to be made of the use of electronic business...

Electron-electron interaction and transfer ionization in fast ion-atom collisions

International Nuclear Information System (INIS)

Voitkiv, A B

2008-01-01

Recently it was pointed out that electron capture occurring in fast ion-atom collisions can proceed via a mechanism which earlier was not considered. In the present paper we study this mechanism in more detail. Similarly as in radiative capture, where the electron transfer occurs due to the interaction with the radiation field and proceeds via emission of a photon, within this mechanism the electron capture is caused by the interaction with another atomic electron leading mainly to the emission of the latter. In contrast to the electron-electron Thomas capture, this electron-electron (E-E) mechanism is basically a first-order one having similarities to the kinematic and radiative capture channels. It also possesses important differences with the latter two. Leading to transfer ionization, this first-order capture mechanism results in the electron emission mainly in the direction opposite to the motion of the projectile ion. The same, although less pronounced, feature is also characteristic for the momenta of the target recoil ions produced via this mechanism. It is also shown that the action of the E-E mechanism is clearly seen in recent experimental data on the transfer ionization in fast proton-helium collisions.

Determination of electron temperature and electron density in ...

African Journals Online (AJOL)

It is seen that the electron temperature increases from 5.8 × 102 oK to 7.83 × 104 oK as the pd is reduced from 130mm Hg × mm to 60 mm Hg × mm for argon. The electron densities increases from 2.8 × 1011/cm3 to 3.2 × 1011 /cm3 for the same variation of pds. For air the electron temperature increases from 3.6 × 104 oK to ...

Optimising electron microscopy experiment through electron optics simulation

Energy Technology Data Exchange (ETDEWEB)

Kubo, Y. [CEMES-CNRS, 29 Rue Jeanne Marvig, 31055 Toulouse France (France); Hitachi High-Technologies Corporation, 882, Ichige, Hitachinaka, Ibaraki 312-8504 (Japan); Gatel, C.; Snoeck, E. [CEMES-CNRS, 29 Rue Jeanne Marvig, 31055 Toulouse France (France); Houdellier, F., E-mail: florent.houdellier@cemes.fr [CEMES-CNRS, 29 Rue Jeanne Marvig, 31055 Toulouse France (France)

2017-04-15

We developed a new type of electron trajectories simulation inside a complete model of a modern transmission electron microscope (TEM). Our model incorporates the precise and real design of each element constituting a TEM, i.e. the field emission (FE) cathode, the extraction optic and acceleration stages of a 300 kV cold field emission gun, the illumination lenses, the objective lens, the intermediate and projection lenses. Full trajectories can be computed using magnetically saturated or non-saturated round lenses, magnetic deflectors and even non-cylindrical symmetry elements like electrostatic biprism. This multi-scale model gathers nanometer size components (FE tip) with parts of meter length (illumination and projection systems). We demonstrate that non-trivial TEM experiments requiring specific and complex optical configurations can be simulated and optimized prior to any experiment using such model. We show that all the currents set in all optical elements of the simulated column can be implemented in the real column (I2TEM in CEMES) and used as starting alignment for the requested experiment. We argue that the combination of such complete electron trajectory simulations in the whole TEM column with automatic optimization of the microscope parameters for optimal experimental data (images, diffraction, spectra) allows drastically simplifying the implementation of complex experiments in TEM and will facilitate the development of advanced use of the electron microscope in the near future. - Highlights: • Using dedicated electron optics software, we calculate full electrons trajectories inside a modern transmission electron microscope. • We have determined how to deal with multi-scale electron optics elements like high voltage cold field emission source. • W • e have succeed to model both weak and strong magnetic lenses whether in saturated or unsaturated conditions as well as electrostatic biprism and magnetic deflectors. • We have applied this model

Optimising electron microscopy experiment through electron optics simulation

International Nuclear Information System (INIS)

Kubo, Y.; Gatel, C.; Snoeck, E.; Houdellier, F.

2017-01-01

We developed a new type of electron trajectories simulation inside a complete model of a modern transmission electron microscope (TEM). Our model incorporates the precise and real design of each element constituting a TEM, i.e. the field emission (FE) cathode, the extraction optic and acceleration stages of a 300 kV cold field emission gun, the illumination lenses, the objective lens, the intermediate and projection lenses. Full trajectories can be computed using magnetically saturated or non-saturated round lenses, magnetic deflectors and even non-cylindrical symmetry elements like electrostatic biprism. This multi-scale model gathers nanometer size components (FE tip) with parts of meter length (illumination and projection systems). We demonstrate that non-trivial TEM experiments requiring specific and complex optical configurations can be simulated and optimized prior to any experiment using such model. We show that all the currents set in all optical elements of the simulated column can be implemented in the real column (I2TEM in CEMES) and used as starting alignment for the requested experiment. We argue that the combination of such complete electron trajectory simulations in the whole TEM column with automatic optimization of the microscope parameters for optimal experimental data (images, diffraction, spectra) allows drastically simplifying the implementation of complex experiments in TEM and will facilitate the development of advanced use of the electron microscope in the near future. - Highlights: • Using dedicated electron optics software, we calculate full electrons trajectories inside a modern transmission electron microscope. • We have determined how to deal with multi-scale electron optics elements like high voltage cold field emission source. • W • e have succeed to model both weak and strong magnetic lenses whether in saturated or unsaturated conditions as well as electrostatic biprism and magnetic deflectors. • We have applied this model

Lead-Free Electronics: Impact for Space Electronics

Science.gov (United States)

Sampson, Michael J.

2010-01-01

Pb is used as a constituent in solder alloys used to connect and attach electronic parts to printed wiring boards (PWBs). Similar Pbbearing alloys are electroplated or hot dipped onto the terminations of electronic parts to protect the terminations and make them solderable. Changing to Pb-free solders and termination finishes has introduced significant technical challenges into the supply chain. Tin/lead (Sn/Pb) alloys have been the solders of choice for electronics for more than 50 years. Pb-free solder alloys are available but there is not a plug-in replacement for 60/40 or 63/37 (Sn/Pb) alloys, which have been the industry workhorses.

Observation of electron plasma waves in plasma of two-temperature electrons

International Nuclear Information System (INIS)

Ikezawa, Shunjiro; Nakamura, Yoshiharu.

1981-01-01

Propagation of electron plasma waves in a large and unmagnetized plasma containing two Maxwellian distributions of electrons is studied experimentally. Two kinds of plasma sources which supply electrons of different temperature are used. The temperature ratio is about 3 and the density ratio of hot to cool electrons is varied from 0 to 0.5. A small contamination of hot electrons enhances the Landau damping of the principal mode known as the Bohm-Gross mode. When the density of hot electrons is larger than about 0.2, two modes are observed. The results agree with theoretical dispersion relations when excitation efficiencies of the modes are considered. (author)

Electron energy and electron trajectories in an inverse free-electron laser accelerator based on a novel electrostatic wiggler

Science.gov (United States)

Nikrah, M.; Jafari, S.

2016-06-01

We expand here a theory of a high-gradient laser-excited electron accelerator based on an inverse free-electron laser (inverse-FEL), but with innovations in the structure and design. The electrostatic wiggler used in our scheme, namely termed the Paul wiggler, is generated by segmented cylindrical electrodes with applied oscillatory voltages {{V}\\text{osc}}(t) over {{90}\\circ} segments. The inverse-FEL interaction can be described by the equations that govern the electron motion in the combined fields of both the laser pulse and Paul wiggler field. A numerical study of electron energy and electron trajectories has been made using the fourth-order Runge-Kutta method. The results indicate that the electron attains a considerable energy at short distances in this device. It is found that if the electron has got sufficient suitable wiggler amplitude intensities, it can not only gain higher energy in longer distances, but also can retain it even after the passing of the laser pulse. In addition, the results reveal that the electron energy gains different peaks for different initial axial velocities, so that a suitable small initial axial velocity of e-beam produces substantially high energy gain. With regard to the transverse confinement of the electron beam in a Paul wiggler, there is no applied axial guide magnetic field in this device.

Plasmaspheric electron content

International Nuclear Information System (INIS)

Hartmann, G.K.

1978-01-01

Measurements of the plasmaspheric electron content are reviewed with particular reference to the ATS-6 radio beacon experiment. From the review, it appears likely that measurement of the plasmaspheric electron content is the only one capable of monitoring electron fluxes continuously between L 1 and L 2. Some recent important results deduced from plasmaspheric electron content measurements are discussed

A 20 keV electron gun system for the electron irradiation experiments

International Nuclear Information System (INIS)

Mahapatra, S.K.; Dhole, S.D.; Bhoraskar, V.N.

2005-01-01

An electron gun consisting of cathode, focusing electrode, control electrode and anode has been designed and fabricated for the electron irradiation experiments. This electron gun can provide electrons of any energy over the range 1-20 keV, with current upto 50 μA. This electron gun and a Faraday cup are mounted in the cylindrical chamber. The samples are fixed on the Faraday cup and irradiated with electrons at a pressure ∼10 -7 mbar. The special features of this electron gun system are that, at any electron energy above 1 keV, the electron beam diameter can be varied from 5 to 120 mm on the Faraday cup mounted at a distance of 200 mm from the anode in the chamber. The variation in the electron current over the beam spot of 120 mm diameter is less than 15% and the beam current stability is better than 5%. This system is being used for studying the irradiation effects of 1-20 keV energy electrons on the space quality materials in which the irradiation time may vary from a few tens of seconds to hours

A 20 keV electron gun system for the electron irradiation experiments

Energy Technology Data Exchange (ETDEWEB)

Mahapatra, S.K. [Department of Physics, University of Pune, Pune 411007 (India); Dhole, S.D. [Department of Physics, University of Pune, Pune 411007 (India); Bhoraskar, V.N. [Department of Physics, University of Pune, Pune 411007 (India)]. E-mail: vnb@physics.unipune.ernet.in

2005-01-01

An electron gun consisting of cathode, focusing electrode, control electrode and anode has been designed and fabricated for the electron irradiation experiments. This electron gun can provide electrons of any energy over the range 1-20 keV, with current upto 50 {mu}A. This electron gun and a Faraday cup are mounted in the cylindrical chamber. The samples are fixed on the Faraday cup and irradiated with electrons at a pressure {approx}10{sup -7} mbar. The special features of this electron gun system are that, at any electron energy above 1 keV, the electron beam diameter can be varied from 5 to 120 mm on the Faraday cup mounted at a distance of 200 mm from the anode in the chamber. The variation in the electron current over the beam spot of 120 mm diameter is less than 15% and the beam current stability is better than 5%. This system is being used for studying the irradiation effects of 1-20 keV energy electrons on the space quality materials in which the irradiation time may vary from a few tens of seconds to hours.

Effect of electron beam on the properties of electron-acoustic rogue waves

Science.gov (United States)

El-Shewy, E. K.; Elwakil, S. A.; El-Hanbaly, A. M.; Kassem, A. I.

2015-04-01

The properties of nonlinear electron-acoustic rogue waves have been investigated in an unmagnetized collisionless four-component plasma system consisting of a cold electron fluid, Maxwellian hot electrons, an electron beam and stationary ions. It is found that the basic set of fluid equations is reduced to a nonlinear Schrodinger equation. The dependence of rogue wave profiles and the associated electric field on the carrier wave number, normalized density of hot electron and electron beam, relative cold electron temperature and relative beam temperature are discussed. The results of the present investigation may be applicable in auroral zone plasma.

Electron cooling and recombination experiments with an adiabatically expanded electron beam

International Nuclear Information System (INIS)

Pastuszka, S.; Heidelberg Univ.; Schramm, U.; Heidelberg Univ.; Grieser, M.; Heidelberg Univ.; Broude, C.; Heidelberg Univ.; Grimm, R.; Heidelberg Univ.; Habs, D.; Heidelberg Univ.; Kenntner, J.; Heidelberg Univ.; Miesner, H.J.; Heidelberg Univ.; Schuessler, T.; Heidelberg Univ.; Schwalm, D.; Heidelberg Univ.; Wolf, A.; Heidelberg Univ.

1996-01-01

Magnetically guided electron beams with transverse temperatures reduced with respect to the cathode temperature by a factor of more than 7 were realized in the electron cooling device of the heavy-ion storage ring TSR and the effect of the reduced transverse temperature in recombination and electron cooling experiments was studied. Measured dielectronic recombination resonances at low relative energy and spectra of laser-stimulated recombination indicate that transverse electron temperatures of about 17 meV have been obtained at cathode temperatures of about 110 meV. The temperature dependence of the spontaneous electron-ion recombination rate during electron cooling was investigated and found to follow the inverse square-root law expected from the theory of radiative recombination, although the measured absolute rates are higher than predicted. A new method based on analyzing the intensity of the fluorescence light emitted during simultaneous laser and electron cooling is used to measure the longitudinal electron cooling force in a range of relative velocities extending over two orders of magnitude (10 5 -10 7 cm/s). The results confirm the occurrence of 'magnetized electron cooling' also at the reduced transverse temperature and show that, compared to earlier measurements at the high transverse temperature, the cooling force increases by about a factor of 2; a considerably larger increase by a factor of ∼5 would be expected if 'magnetized electron cooling' would not exist. (orig.)