Pomegranate transplant stress can be ameliorated by rhizophagus intraradices under nursery management

Arbuscular mycorrhizal fungi (AMF) establish an obligate mutualistic symbiosis with many plant species, increasing the uptake of phosphorous and other low-mobile nutrients by roots. In addition, AMF improve biotic and abiotic stress tolerance of host plants. Under these conditions, reactive oxygen species (ROS) increase occasional damage to proteins, lipids and DNA. Antioxidative enzymes in plants can play an important role in detoxifying ROS, thereby alleviating oxidative stress. In nursery practices, plants are subjected at least to two transplant conditions before being transplanted outside. It is important to achieve an optimal plant size to withstand environmental or other stresses when plants are transplanted into the field. The transplantation process can be considered a stress because plants have to adapt to new abiotic and biotic (rhizospheric) conditions. The aim of this study was to evaluate the effect of two Rhizophagus intraradices (N.C. Schenck & G.S. Sm.) C. Walker & A. Schüßler strains, GA5 and GC2, single and co-inoculated under two-transplant soil conditions, sterile and non-sterile, using cuttings of pomegranate (Punica granatum L.) as a model plant. These results showed that the GA5 single strain-inoculated plants improved growth and antioxidative enzyme responses to two transplant stress conditions. In conclusion, early mycorrhizal inoculation generates healthy plants that are more protected against environmental conditions, thereby improving plant transplant stress tolerance.Fil: Bompadre, Maria Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Colombo, Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Silvani, Vanesa Analia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Fernandez Bidondo, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Pardo, Alejandro Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Micología Molecular; ArgentinaFil: Ocampo, Juan Antonio. Consejo Superior de Investigaciones Científicas. Estación Experimental del Zaidín; EspañaFil: Godeas, Alicia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin

Development of arbuscular mycorrhizal fungi in the presence of different patterns of Trifolium repens shoot flavonoids

We tested the effects of the flavonoid 3-methoxi-5,6,7,8-hydroxy-4'hydroxy flavone (NMHTV) isolated from shoots of non arbuscular mycorrhizal (AM) inoculated clover, and of the flavonoids 5,6,7,8-hydroxy-3-methoxy flavone (MH-1); 5,6,7,8-hydroxy-4'- hydroxy flavone (MH-2); and 5,7-hydroxy-3,4'-methoxy flavone (MH-3); isolated from AM clover (Trifolium repens) shoots, on spore germination, hyphal length, hyphal branches and the number of cluster of auxiliary cells or the number of secondary spores (Presymbiotic stage) and on the number of entry points and the percentage of AM colonized root of tomato (Lycopersicum esculentum) by the AM fungi Gigaspora rosea, Giaspora margarita, Glomus mosseae and Glomus intraradices (Symbiotic stage). Non significant effects of the flavonoids isolated from the shoot of mycorrhizal colonized clover on the presymbiotic and symbiotic stages of Gigaspora and Glomus endophytes were found. The flavonoid NMHTV isolated from non AM clover shoot, did not affect the percentage of germination of spores but significantly increased (P < 0.05) the other steps of the presymbiotic stage of Gi. margarita spores when 2 μM concentration was used. The symbiotic stage of Gi. margarita was also significantly increased when 2 μM of the flavonoid NMHTV was applied. This flavonoid had no effect on the presymbiotic development of G. mosseae, G. intraradices and Gi. rosea except when 8 μM concentration was used, which inhibited the hyphal length of Gi. rosea. These results suggest the possible implication of the flavonoid NMHTV in the susceptibility of tomato roots to the AM formation by Gi. margarita. The absence of stimulation of the AM presymbiotic and symbiotic stages in tomato by exogenous application of the newly synthesized flavonoids MH-1, MH-2, and MH-3, in clover shoots after AM colonization, indicated that the autorregulation of the AM symbiosis can be, at least partially, due to the disappearance of flavonoids in AM colonized plants that stimulated the AM symbiosis.Fil: Scervino, Jose Martin. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; ArgentinaFil: Ponce, María Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Della Mónica, Ivana Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Vierheilig, Horst. Universitat Fur Bodenkultur Wien; Austria. Consejo Superior de Investigaciones Científicas. Estación Experimental del Zaidín; EspañaFil: Ocampo, Juan Antonio. Consejo Superior de Investigaciones Científicas. Estación Experimental del Zaidín; EspañaFil: Godeas, Alicia Margarita. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Suppressive soil against Sclerotinia sclerotiorum as a source of potential biocontrol agents: selection and evaluation of Clonostachys rosea BAFC1646

The fungal diversity structures of soils that are suppressive and non-suppressive to Sclerotinia sclerotiorum were characterised and screened for fungal strains antagonistic to the S. sclerotiorum pathogen. Soil suppressiveness was associated with a particular fungal diversity structure. Principal component analysis showed that antagonism by fungal species in suppressive soils was associated with the occurrence of Fusarium oxysporum, Fusarium solani, Talaromyces flavus var. flavus and Clonostachys rosea f. rosea. In particular, C. rosea f. rosea occurred exclusively in suppressive soil samples, suggesting that this morpho-species plays an important role in suppression of S. sclerotiorum diseases. One strain of C. rosea f. rosea (BAFC1646) was selected for further experiments. Dual-culture assays confirmed the antagonistic behaviour of C. rosea f. rosea BAFC1646 against three different S. sclerotiorum strains. Antifungal activity was corroborated by diffusion assays with metabolite extracts. Greenhouse assays with soybean plants showed that the selected C. rosea f. rosea strain reduced the percentage of dead plants when co-inoculated with S. sclerotiorum. In addition, inclusion of C. rosea f. rosea alone increased shoot lengths significantly. In this work, we established the involvement of fungal species in soil suppressiveness and in further assays confirmed that C. rosea f. rosea BAFC1646 exhibits a bioprotective effect against S. sclerotiorum in soybean plants.Fil: Rodriguez, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Rothen, Carolina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Lo, Tai En. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Cabrera, Gabriela Myriam. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis y Métodos Físicos en Química Orgánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Unidad de Microanálisis y Métodos Físicos en Química Orgánica; ArgentinaFil: Godeas, Alicia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; Argentin

Influence of the insecticide dimethoate on arbuscular mycorrhizal colonization and growth in soybean plants

Application to the soil of the insecticide dimethoate had no effect on the growth of soybean colonized by the arbuscular mycorrhizal (AM) fungus Glomus mosseae and by the indigenous AM fungus. The application of the recommended concentration of dimethoate decreased the percentage of colonization of soybean by the indigenous AM population, but no significant effect was observed on the colonization of soybean inoculated with G. mosseae. The insecticide did not affect the germination of G. mosseae spores; however, 0.5 mg/l of dimethoate increased the germination of Gigaspora roseae and 5 mg/l of dimethoate decreased the germination of Scutellospora castaneae spores

Effect of the fungicide benomyl on spore germination and hyphal length of the arbuscular mycorrhizal fungus Glomus mosseae

The fungicide benomyl inhibited spore germination and hyphal length of the arbuscular mycorrhizal fungus Glomus mosseae when applied at doses of 21.25 μg/ml (agronomic dose), 10.62 μg/ml and 10 μg/ml. G. mosseae was able to germinate in the presence of 2.12 μg/ml of benomyl, and the percentage of spore germination was unaffected by dosis of 0.1, 0.01 and 0.001 μg/ml of the fungicide. However, all doses of fungicide tested in this study decreased the hyphal length. When ungerminated G. mosseae spores previously exposed to benomyl were transferred to water-agar medium without benomyl, the maximum germination was 16%. Small spores of G. mosseae were more resistant to benomyl than the larger ones. Our results show some of the factors which can explain the variability of the effect of benomyl on arbuscular mycorrhizal fungi

Growth dynamics of geographically different arbuscular mycorrhizal fungal isolates belonging to the 'Rhizophagus clade' under monoxenic conditions

The growth dynamics of extraradical mycelium and spore formation of fourteen 'Rhizophagus' isolates from different sites in Argentina were evaluated under monoxenic conditions. A modified Gompertz model was used to characterize the development of mycelium and spores for each isolate under the same conditions. The lag time, maximal growth rate, and total quantity of both extraradical hyphae and spores were determined. Wide variability among isolates was detected and all growth parameters were significantly altered by fungal isolate. Discriminant analysis differentiated isolates primarily based on the extent of extraradical hyphae produced, yet such differences did not conclusively correspond to phylogenetic relationships among closely related isolates based on partial SSU sequences. Given that the 'Rhizophagus' isolates were grown under controlled conditions for many generations, the expression of phenotypic variability could be attributed to genetic differences that are not completely resolved by phylogenetic analysis employing the small ribosomal gene

A7. SITUAZIONE NAZIONALE: CORPI IDRICI INTERESSATI DA CIANOBATTERI TOSSICI

I cianobatteri sono diffusi in moltissimi ambienti acquatici, dove possono produrre cianotossine con diversi profili tossicologici. Il presente rapporto riporta le linee guida per la gestione delle fioriture di cianobatteri nelle acque di balneazione, elaborate da un gruppo di esperti. La prima parte sintetizza le attuali conoscenze scientifiche su vari aspetti, fra cui la loro presenza nei laghi italiani, le caratteristiche chimiche e tossicologiche delle varie cianotossine, gli effetti osservati sulla salute dell\u2019uomo e la valutazione del rischio. La seconda parte definisce le linee guida per prevenire effetti dannosi per la salute dei bagnanti e gestire il rischio associato alle fioriture. Vengono fornite indicazioni per pianificare attivit\ue0 di monitoraggio ambientale e sorveglianza sanitaria nelle aree a maggiore criticit\ue0. Viene inoltre presentato un sistema di reportistica, ambientale e sanitario, anche allo scopo di uniformare le informazioni a livello nazionale. Il rapporto \ue8 completato dalle indicazioni tecniche rivolte alle strutture territoriali preposte.Cyanobacteria thrive in many aquatic environments, where they can produce cyanotoxins with different toxicological profiles. This report provides the guidelines for the management of cyanobacterial blooms in bathing water, put together by a group of experts. The first part summarizes the current scientific knowledge on various aspects, including their presence in the Italian lakes, chemical and toxicological characteristics of different cyanotoxins, the observed effects on human health and the risk assessment. The second part defines the guidelines to prevent harmful effects on the health of bathers and manage the risk associated with blooms. It provides recommendations for planning environmental monitoring activities and a health surveillance system in most critical areas. It also introduces an environmental and health reporting system, with the purpose to standardize the information at national level too. The report is supplemented by technical information aimed at territorial authorities in charge

Efecto diferencial de dos cepas de Rhizophagus intraradices sobre la biomasa y el rendimiento y composición de aceites esenciales de Calamintha nepeta

El objetivo de este trabajo fue determinar, bajo condiciones de invernadero, el efecto de dos cepas geográficamente diferentes de Rhizophagus intraradices (M3 y GA5) sobre la biomasa total y el rendimiento y composición de aceites esenciales (AE) de Calamintha nepeta, con fertilización fosforada (P) o sin esta. La biomasa de la planta no fue significativamente afectada por ningún tratamiento, y se observaron valores más altos en las plantas control. Las cepas mostraron diferencias en sus tasas de colonización y en las respuestas a la fertilización con fósforo: M3 redujo sus valores de colonización, mientras que GA5 no los modificó. En ausencia de fertilización fosforada, las plantas colonizadas por ambas cepas presentaron rendimientos de AE diferentes a aquellos de las plantas control: M3 los aumentó y GA5 los disminuyó. La composición porcentual de AE no fue modificada significativamente por ninguno de los tratamientos. M3 podría ser considerada como un posible bioinoculante fúngico para la producción de C. nepeta destinada al mercado de las plantas aromáticas.The aim of this work was to determine the effects of two geographically different strains of Rhizophagus intraradices (M3 and GA5) on the total biomass and essential oil (EO) yield and composition of Calamintha nepeta, with or without phosphorus (P) fertilization, under greenhouse conditions.The plant biomass was not significantly affected by any of the treatments, showing higher values in control plants. Strains had a differential response in their root colonization rates: M3 reduced these parameters while GA5 did not modify them. Both strains affected EO yield in absence of P fertilization: M3 promoted EO yield in C. nepeta plants and GA5 resulted in negative effects. The percentage composition of EO was not significantly modified by either strain or P fertilization. M3 strain could be a potential fungal bioinoculant for production and commercialization of C. nepeta in the aromatic plant market.Fil: Colombo, Roxana. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Biodiversidad y Biologia Experimental; ArgentinaFil: Martinez, Alicia Elba. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Biodiversidad y Biologia Experimental; ArgentinaFil: Fernández Di Pardo, Agustina. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Biodiversidad y Biologia Experimental; ArgentinaFil: Fernandez Bidondo, Laura. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Biodiversidad y Biologia Experimental; ArgentinaFil: Van Baren, Catalina Maria. Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Instituto de Química y Metabolismo del Fármaco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco (i); ArgentinaFil: Di Leo Lira, Paola Maria del Rosario. Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Instituto de Química y Metabolismo del Fármaco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco (i); ArgentinaFil: Godeas, Alicia Margarita. Universidad de Buenos Aires. Facultad de Cs.exactas y Naturales. Departamento de Biodiversidad y Biologia Experimental; Argentin

Fungal root colonization of Puccinellia frigida (Phil.) Johnston, a dominant grass species inhabiting the margins of high-altitude hypersaline Andean wetlands

High-altitude hypersaline Andean wetlands are considered stressful environments by the prevalence of extreme abiotic conditions affecting both plant host and fungal root endophytes. Puccinellia frigida (Phil.) Johnston, a dominant plant species inhabiting the margins of these wetlands over 4000 m.a.s.l. in Northwest Argentina, is frequently colonized by fungal root endophytes. Here we examined the nature and dynamics of fungal root colonization on this plant species in three different wetlands (six sampling sites) and two growing seasons. Morphologically diverse septate fungi and chytrids were observed in root samples of P. frigida in all sampling sites, whereas arbuscular mycorrhizal fungi were found only in two sites. The level of colonization of chytrids and septate fungi differed significantly both between sites and seasons. Soil organic matter and electrical conductivity were the only habitat parameters significantly related to the observed differences. The widespread occurrence of non-destructive fungal associations suggest an important role for plant survival in extreme environments.Fil: Silvani, Vanesa Analia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación en Biociencias Agrícolas y Ambientales. Grupo Vinculado Departamento Biodiversidad y Biología Experimental Universidad de Buenos Aires - Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Rothen, Carolina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación en Biociencias Agrícolas y Ambientales. Grupo Vinculado Departamento Biodiversidad y Biología Experimental Universidad de Buenos Aires - Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Rodriguez, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación en Biociencias Agrícolas y Ambientales. Grupo Vinculado Departamento Biodiversidad y Biología Experimental Universidad de Buenos Aires - Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Cisneros, Gabriela Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación en Biociencias Agrícolas y Ambientales. Grupo Vinculado Departamento Biodiversidad y Biología Experimental Universidad de Buenos Aires - Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Godeas, Alicia Margarita. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación en Biociencias Agrícolas y Ambientales. Grupo Vinculado Departamento Biodiversidad y Biología Experimental Universidad de Buenos Aires - Instituto de Investigaciones en Biociencias Agrícolas y Ambientales; ArgentinaFil: Aranda Rickert, Adriana Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientificas y Transferencia Tecnológica de Anillaco; ArgentinaFil: Fracchia, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientificas y Transferencia Tecnológica de Anillaco; Argentin

Identification of ammonium anomalies by SWIR reflectance spectroscopy: Implications for mining exploration

The existence of ammonium anomalies in mineralized deposits in Argentina is presented. These anomalies are given by the substitution of potassium ion by ammonium ion in certain feldspars, clay minerals and sulfates. This substitution doesn't produce physical changes either in the minerals or the host rocks. Ammonium-bearing minerals have been found in several hydrothermally altered metallic deposits. Ammonium ion is specially sensible to SWIR reflectance spectroscopy method, so it became an ideal, easy and valuable tool for ammonium anomalies detection. Although ammonium-bearing minerals are not always associated with metallic ore, they can be used as an exploration guide, being thus a very useful prospective method for metallic deposits in general. © 2006 Asociación Geológica Argentina.Fil:Godeas, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Litvak, V.D. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina