Este trabajo resume el contenido de la jornada de difusión científico - técnica que llevó por tít... more Este trabajo resume el contenido de la jornada de difusión científico - técnica que llevó por título "La convergencia digital en los medios de comunicación valencianos", celebrada en la Universitat de València en octubre de 2007.
Los contenidos reflejan, por una parte, el estado de la cuestión investigadora en materia de ciberperiodismo; por otra, la presencia en Internet de los medios locales en diversas CCAA españolas (Galicia, Cataluña, el País Vasco y la Comunidad Valenciana); y por último, el estudio de diversos casos prácticos que abarcan tanto el análisis de medios locales como confidenciales y weblogs.
Rotaviruses are the most important agent of severe gastroenteritis in young children. Early in in... more Rotaviruses are the most important agent of severe gastroenteritis in young children. Early in infection, these viruses take over the host translation machinery, causing a severe shutoff of cell protein synthesis while viral proteins are efficiently synthesized. In infected cells, there is an accumulation of the cytoplasmic poly(A)-binding protein in the nucleus, induced by the viral protein NSP3. Here we found that poly(A)-containing mRNAs also accumulate and become hyperadenylated in the nuclei of infected cells. Using reporter genes bearing the untranslated regions (UTRs) of cellular or viral genes, we found that the viral UTRs do not determine the efficiency of translation of mRNAs in rotavirus-infected cells. Furthermore, we showed that while a polyadenylated reporter mRNA directly delivered into the cytoplasm of infected cells was efficiently translated, the same reporter introduced as a plasmid that needs to be transcribed and exported to the cytoplasm was poorly translated. ...
Revista de la ciencia del suelo y nutrición vegetal, 2010
Arbuscular mycorrhizal fungi (AMF) and their product glomalin (GRSP) play a decisive role in the ... more Arbuscular mycorrhizal fungi (AMF) and their product glomalin (GRSP) play a decisive role in the soil aggregation, affecting the carbon (C) dynamics in agroecosystems. Tillage affects the AMF activity and GRSP content, influencing the stability and the soil C forms as well. The aim of this study was to compare the effect of no tillage (NT) and conventional tillage (CT) on: i) arbuscular mycorrhizal hyphal length and GRSP content; ii) the nature of soil organic matter by means of physical fractionation (free particulate organic matter [fPOM]; occluded particulate organic matter [oPOM] and mineral-associated soil organic matter [Mineral]), as well as chemical fractionation (fulvic acid, humic acid and humin), and iii) the relationships between AMF parameters, soil carbon and water stable aggregates (WSA) in a Mollisol of Central Chile managed for 6 years under NT and CT using a wheat-corn rotation. Higher values in the AMF hyphal length, GRSP and WSA in NT compared with CT were observed. Significant relationships were found between GRSP and WSA (r = 0.66, p < 0.01) and total mycelium and GRSP (r = 0.58, p< 0.05). The total carbon increased 44% under NT compared with CT. The chemical fractionation showed percentage greater than 95% for humim in both treatments. Physical fractionation indicates that the higher part of the SOC (89.4 -95.1%) was associated with the mineral fraction.
Arbuscular mycorrhizal (AM) association plays a key role in the sustainability of terrestrial pla... more Arbuscular mycorrhizal (AM) association plays a key role in the sustainability of terrestrial plant ecosystems, in particular those presenting limitations for the establishment and subsequent growth of plants. In Chile, more than 50% of arable soils are originated from volcanic ashes, showing in general several constraints to crop production, such as low pH, high exchangeable aluminum content and low levels of available P. Under these conditions, the management of AM fungal propagules using adequate cultural management practices emerges as a successful alternative in order to maximize the positive effects of AM symbiosis on plant growth in these types of soil. This review presents the results of several years of research about the effect of different agronomic and forest management practices on the density and functionality of the native fungal populations in volcanic soils from Southern Chile, and their subsequent effect on the improvement of soil characteristics. These investigations have contributed to a better understanding of the role played by AM symbiosis in such soils and provide guidance on the most appropriate alternatives to increase its presence and functionality.
... FERNANDO R. BORIE 1 , ROSA RUBIO, ALFREDO MORALES & CARLOS CASTILLO. ... Estudios recient... more ... FERNANDO R. BORIE 1 , ROSA RUBIO, ALFREDO MORALES & CARLOS CASTILLO. ... Estudios recientes han mostrado que es mayor la densidad de micelio extraradical en suelos donde no ha alterado su estructura, como es el caso de la labranza reducida y cero labranza ...
ABSTRACT summaryThree isolates of vesicular-arbuscular (VA) mycorrhizal fungi, belonging to the s... more ABSTRACT summaryThree isolates of vesicular-arbuscular (VA) mycorrhizal fungi, belonging to the species Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, G. fasciculatum (Taxter sensu Gerd.) Gerd, and Trappe, and G. caledonium (Nicol. and Gerd.) Trappe and Gerd, were inoculated in dual combinations with six strains of Rhizobium meliloti with the aim of testing these combinations for functional compatibility with their common host plant, the legume Medicago sativa L. Symbiotic efficiency (promotion of plant growth and N and P nutrition) was found to be dependent on the particular combination of Rhizobium strain and Glomus species indicating selective and specific compatibilities between strains and isolates of the two types of microsymbiont, but also between them and the common host plant. Observed effects on plant growth were in general, though not always, related to the extent of VA mycorrhizal colonization. Although the different mycorrhizal and/or rhizobial treatments produced different effects on plant growth, the rate of nodule formation on M. sativa roots remained constant. Most mycorrhizal treatments increased the concentration and/or content of N in plant shoots but effectiveness was in the order: G. fasciculatum &gt; G. mosseae &gt; G. caledonium. In some cases, this increase in N-content may be a consequence of a P-mediated stimulation of N2-fixation by VA mycorrhiza, as ascertained using 15N. In other instances, however, the increase seems to reflect a VA mycorrhizal-mediated enhancement of N-uptake from soil. VA mycorrhizal inoculation decreased the concentration of Ca and Mg in plant shoots and a buffering effect of VA mycorrhiza in situations of nutrient excess in soil is proposed.
... Ecology of VA mycorrhizal fungi in temperate agroecosystems. In: Proc. 7 th NACOM. DM Sylvia,... more ... Ecology of VA mycorrhizal fungi in temperate agroecosystems. In: Proc. 7 th NACOM. DM Sylvia, LL Hung and JH Graham (ed.) p.2-4 Florida. 7. Rhodes, LH 1981. The use of mycorrhizae in crop production systems. Outlook in Agriculture 10: 275-281. 8. Mc Lachlan, KD 1976. ...
Abstract Acidification and aluminum (Al) phytotoxicity are the most important constraints for pla... more Abstract Acidification and aluminum (Al) phytotoxicity are the most important constraints for plant growing in volcanic soils from southern Chile. This study was conducted to evaluate the effects of arbuscular mycorrhizal (AM) fungus inoculation and liming on growth and ...
The effect of arbuscular-mycorrhizal (AM) fungus Glomus etunicatum inoculation in interaction wit... more The effect of arbuscular-mycorrhizal (AM) fungus Glomus etunicatum inoculation in interaction with two sources of phosphorus (P) [soluble P and partially acidulated phosphate rock (pa-PR)] at three rates (17, 43, and 86 kg P ha) was studied in an acidic natural soil using wheat (Triticum aestivum L.) as host plant. Shoot and root dry biomass, AM colonized root length, macro-micronutrients content and soil
ABSTRACT The aim of this work was to study, in glasshouse conditions, the effect of arbuscular my... more ABSTRACT The aim of this work was to study, in glasshouse conditions, the effect of arbuscular mycorrhizal fungi (AMF) inoculation on plant growth and fruit quality of chili pepper cv. Cacho de Cabra when plants were transplanted to a sterile (SS) and unsterile substrate (NSS) composed by a mixture of soil-sand-vermiculite. Inocula were Glomus claroideum and a mixture of native HMA strains which were compared with a control. Twice a month, height and flower number and nutritional and chemical fruit characteristics were measured. In SS both HMA inocula increased shoot and root weight and diameter and weight of fruits. Maturation period was also reduced. Under the studied conditions the strains used showed compatibility with host plant which suggests that an effective inoculation of this vegetable could greatly improve its usefulness in industrial processes.
The effect of management systems and crop rotation on soil phosphorus (P) fractions and selected ... more The effect of management systems and crop rotation on soil phosphorus (P) fractions and selected soil properties were studied from 2002 to 2005 on an experiment established in 2001 in a volcanic derived Ultisol from southern Chile. Two tillage systems, no tillage (NT) and conventional tillage (CT), and two crop rotations, oat–wheat and white lupine–wheat were evaluated in order to
Total phosphorus (P), Olsen P, microbial P and different labile P fractions determined by a modif... more Total phosphorus (P), Olsen P, microbial P and different labile P fractions determined by a modified Hedley procedure, together to acid phosphatase (P-ase), pH and organic C, were analyzed in soil from four Nothofagus rainforest ecosystems differing in forest type and management. The sites included two evergreen (EF) and two secondary deciduous (DF) rainforests growing in an Andisol of southern Chile. Samples were collected from the organic layer and from mineral soil at 2–20 cm depth. Total P and phosphorus fractions were highest in evergreen forest soil with the predominance of moderate labile (NaOH–Po) fraction. Olsen P, microbial P, labile P fractions, inorganic P fractions and acid phosphatase were greater in the organic layer than the mineral soil, especially under evergreen forests. Evergreen forest litter affected P cycling enhancing P lability and P-ase activity in soil. Forest management affected P fractions in EF but not in DF forests, and generally did not modify soil properties. Results show that clearing of deciduous forest did not seriously affect the P cycle in this Andisol and confirm the fundamental role of the organic layer in P conservation of these ecosystems.
ABSTRACT Entre las diversas prácticas agrotecnológicas aplicables a sistemas agrícolas de baja in... more ABSTRACT Entre las diversas prácticas agrotecnológicas aplicables a sistemas agrícolas de baja inversión, se consideran la adición de residuos de plantas como una fuente de nutrientes, y el manejo adecuado de la simbiosis micorriza arbuscular (MA). Por ello, el objetivo general de este estudio fue determinar el efecto de la aplicación de residuos de cosecha e inoculación micorrízica sobre el desarrollo y nutrición mineral de plantas de trigo (Triticum aestivum L.) creciendo en un suelo ácido (Typic Distrandepts) y algunos parámetros químicos y biológicos del suelo. Residuos de lupino (Lupinus albus L.) y de trigo se adicionaron al suelo a una dosis equivalente a 6 Mg ha-1, sobre el cual se sembró trigo cv. Otto, con y sin inoculación de una cepa nativa de un hongo MA exógeno (Glomus etunicatum CH 110). La adición de residuos orgánicos incrementaron significativamente el rendimiento de materia seca en un 50-60% y la adquisición mineral de las plantas de trigo hasta en un 100%. Los residuos de trigo incrementaron el pH del suelo y la disponibilidad de P, mientras que los residuos de lupino incrementaron la colonización de hongos MA de 49 a 61%. La inoculación de un hongo MA exógeno disminuyó la adquisición de minerales, especialmente Al, lo que puede contribuir a la disminución de problemas de toxicidad en suelos ácidos.
The addition of plant residues and the appropriate management of arbuscular mycorrhizal (AM) symb... more The addition of plant residues and the appropriate management of arbuscular mycorrhizal (AM) symbioses have been tested in an acidic soil, an Andisol from Southern Chile, to ascertain whether these agro-technologies help plants to withstand potential mineral deficiency and the toxicities inherent to the low pH conditions. Firstly, the effects of legume (lupine) and non-legume (wheat) crop residues on some key root-soil interface activities (including AM development), on mineral acquisition by the plants, and on the yield of wheat growing in the test Andisol were investigated in a pot experiment under greenhouse conditions. Both lupine and wheat residues were added at a rate equivalent to 300 g m -2 to the natural soil. These organic amendments increased soil pH (wheat more than lupine), P availability and AM development (lupine more than wheat), plant performance and mineral acquisition (wheat more than lupine). Because of an increase in mycorrhizal activity, which appeared to be involved in the effect of the added crop (particularly lupine) residues, the role of the AM symbiosis was further investigated in a tailored inoculation assay, using a selected AM fungus (Glomus etunicatum), in interaction with lupine and wheat residues. A significant effect of AM inoculation on the reduction of Zn and Cu, and Mn and Al acquisition was demonstrated, which could be of interest in acid soils with regard to potential toxicity problems.
The aim of this work was to study the early influence of conventional tillage (CT) and no-tillage... more The aim of this work was to study the early influence of conventional tillage (CT) and no-tillage (NT) on arbuscular mycorrhizal fungal (AMF) propagules. A short 2-year-course crop rotation, i.e. trial consisting of a succession of wheat and oat, was studied in a typic Chilean Ultisol from the second to fourth year after the beginning of the experiment. Measurements included mycorrhizal characteristics and some soil properties in order to explain their influence on AMF propagules. Soil samples were taken yearly in autumn (fallow period) and in early spring (flowering). Significant differences in AMF hyphal length were observed between NT and CT in the first year, but such differences disappeared thereafter. No differences in metabolically active hyphae were obtained with wheat or oat under the two tillage systems. Mycorrhizal root colonization was always higher under NT than under CT. The number of AMF spores was also higher under NT than under CT, ranging from 158 to 641 spores per 100 cm 3 . Twenty-two AMF species including eight Glomus spp., six Acaulospora spp., four Scutellospora spp., one Archaeospora sp., one Diversispora sp., one Entrophospora sp. and one Pacispora sp. were observed in both agroecosystems. Higher spore number of Acaulospora spp. was found under wheat than under oat and under CT than under NT, whilst more spores of Scutellospora spp. were observed under NT than under CT. From all mycorrhizal characteristics, spore number could be visualized as an early and useful indicator of the effect of tillage systems on mycorrhizal propagules in short-term experiments.
... nearly all ecosystems, but the application of heavy doses of P fertilizer reduces the ... a r... more ... nearly all ecosystems, but the application of heavy doses of P fertilizer reduces the ... a reduction in mycorrhizal colonization resulted in a decrease of phosphorus absorption in ... Schenck, 1990]); consequently, deeper studies are required to understand these effects under natural ...
Este trabajo resume el contenido de la jornada de difusión científico - técnica que llevó por tít... more Este trabajo resume el contenido de la jornada de difusión científico - técnica que llevó por título "La convergencia digital en los medios de comunicación valencianos", celebrada en la Universitat de València en octubre de 2007.
Los contenidos reflejan, por una parte, el estado de la cuestión investigadora en materia de ciberperiodismo; por otra, la presencia en Internet de los medios locales en diversas CCAA españolas (Galicia, Cataluña, el País Vasco y la Comunidad Valenciana); y por último, el estudio de diversos casos prácticos que abarcan tanto el análisis de medios locales como confidenciales y weblogs.
Rotaviruses are the most important agent of severe gastroenteritis in young children. Early in in... more Rotaviruses are the most important agent of severe gastroenteritis in young children. Early in infection, these viruses take over the host translation machinery, causing a severe shutoff of cell protein synthesis while viral proteins are efficiently synthesized. In infected cells, there is an accumulation of the cytoplasmic poly(A)-binding protein in the nucleus, induced by the viral protein NSP3. Here we found that poly(A)-containing mRNAs also accumulate and become hyperadenylated in the nuclei of infected cells. Using reporter genes bearing the untranslated regions (UTRs) of cellular or viral genes, we found that the viral UTRs do not determine the efficiency of translation of mRNAs in rotavirus-infected cells. Furthermore, we showed that while a polyadenylated reporter mRNA directly delivered into the cytoplasm of infected cells was efficiently translated, the same reporter introduced as a plasmid that needs to be transcribed and exported to the cytoplasm was poorly translated. ...
Revista de la ciencia del suelo y nutrición vegetal, 2010
Arbuscular mycorrhizal fungi (AMF) and their product glomalin (GRSP) play a decisive role in the ... more Arbuscular mycorrhizal fungi (AMF) and their product glomalin (GRSP) play a decisive role in the soil aggregation, affecting the carbon (C) dynamics in agroecosystems. Tillage affects the AMF activity and GRSP content, influencing the stability and the soil C forms as well. The aim of this study was to compare the effect of no tillage (NT) and conventional tillage (CT) on: i) arbuscular mycorrhizal hyphal length and GRSP content; ii) the nature of soil organic matter by means of physical fractionation (free particulate organic matter [fPOM]; occluded particulate organic matter [oPOM] and mineral-associated soil organic matter [Mineral]), as well as chemical fractionation (fulvic acid, humic acid and humin), and iii) the relationships between AMF parameters, soil carbon and water stable aggregates (WSA) in a Mollisol of Central Chile managed for 6 years under NT and CT using a wheat-corn rotation. Higher values in the AMF hyphal length, GRSP and WSA in NT compared with CT were observed. Significant relationships were found between GRSP and WSA (r = 0.66, p < 0.01) and total mycelium and GRSP (r = 0.58, p< 0.05). The total carbon increased 44% under NT compared with CT. The chemical fractionation showed percentage greater than 95% for humim in both treatments. Physical fractionation indicates that the higher part of the SOC (89.4 -95.1%) was associated with the mineral fraction.
Arbuscular mycorrhizal (AM) association plays a key role in the sustainability of terrestrial pla... more Arbuscular mycorrhizal (AM) association plays a key role in the sustainability of terrestrial plant ecosystems, in particular those presenting limitations for the establishment and subsequent growth of plants. In Chile, more than 50% of arable soils are originated from volcanic ashes, showing in general several constraints to crop production, such as low pH, high exchangeable aluminum content and low levels of available P. Under these conditions, the management of AM fungal propagules using adequate cultural management practices emerges as a successful alternative in order to maximize the positive effects of AM symbiosis on plant growth in these types of soil. This review presents the results of several years of research about the effect of different agronomic and forest management practices on the density and functionality of the native fungal populations in volcanic soils from Southern Chile, and their subsequent effect on the improvement of soil characteristics. These investigations have contributed to a better understanding of the role played by AM symbiosis in such soils and provide guidance on the most appropriate alternatives to increase its presence and functionality.
... FERNANDO R. BORIE 1 , ROSA RUBIO, ALFREDO MORALES & CARLOS CASTILLO. ... Estudios recient... more ... FERNANDO R. BORIE 1 , ROSA RUBIO, ALFREDO MORALES & CARLOS CASTILLO. ... Estudios recientes han mostrado que es mayor la densidad de micelio extraradical en suelos donde no ha alterado su estructura, como es el caso de la labranza reducida y cero labranza ...
ABSTRACT summaryThree isolates of vesicular-arbuscular (VA) mycorrhizal fungi, belonging to the s... more ABSTRACT summaryThree isolates of vesicular-arbuscular (VA) mycorrhizal fungi, belonging to the species Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, G. fasciculatum (Taxter sensu Gerd.) Gerd, and Trappe, and G. caledonium (Nicol. and Gerd.) Trappe and Gerd, were inoculated in dual combinations with six strains of Rhizobium meliloti with the aim of testing these combinations for functional compatibility with their common host plant, the legume Medicago sativa L. Symbiotic efficiency (promotion of plant growth and N and P nutrition) was found to be dependent on the particular combination of Rhizobium strain and Glomus species indicating selective and specific compatibilities between strains and isolates of the two types of microsymbiont, but also between them and the common host plant. Observed effects on plant growth were in general, though not always, related to the extent of VA mycorrhizal colonization. Although the different mycorrhizal and/or rhizobial treatments produced different effects on plant growth, the rate of nodule formation on M. sativa roots remained constant. Most mycorrhizal treatments increased the concentration and/or content of N in plant shoots but effectiveness was in the order: G. fasciculatum &gt; G. mosseae &gt; G. caledonium. In some cases, this increase in N-content may be a consequence of a P-mediated stimulation of N2-fixation by VA mycorrhiza, as ascertained using 15N. In other instances, however, the increase seems to reflect a VA mycorrhizal-mediated enhancement of N-uptake from soil. VA mycorrhizal inoculation decreased the concentration of Ca and Mg in plant shoots and a buffering effect of VA mycorrhiza in situations of nutrient excess in soil is proposed.
... Ecology of VA mycorrhizal fungi in temperate agroecosystems. In: Proc. 7 th NACOM. DM Sylvia,... more ... Ecology of VA mycorrhizal fungi in temperate agroecosystems. In: Proc. 7 th NACOM. DM Sylvia, LL Hung and JH Graham (ed.) p.2-4 Florida. 7. Rhodes, LH 1981. The use of mycorrhizae in crop production systems. Outlook in Agriculture 10: 275-281. 8. Mc Lachlan, KD 1976. ...
Abstract Acidification and aluminum (Al) phytotoxicity are the most important constraints for pla... more Abstract Acidification and aluminum (Al) phytotoxicity are the most important constraints for plant growing in volcanic soils from southern Chile. This study was conducted to evaluate the effects of arbuscular mycorrhizal (AM) fungus inoculation and liming on growth and ...
The effect of arbuscular-mycorrhizal (AM) fungus Glomus etunicatum inoculation in interaction wit... more The effect of arbuscular-mycorrhizal (AM) fungus Glomus etunicatum inoculation in interaction with two sources of phosphorus (P) [soluble P and partially acidulated phosphate rock (pa-PR)] at three rates (17, 43, and 86 kg P ha) was studied in an acidic natural soil using wheat (Triticum aestivum L.) as host plant. Shoot and root dry biomass, AM colonized root length, macro-micronutrients content and soil
ABSTRACT The aim of this work was to study, in glasshouse conditions, the effect of arbuscular my... more ABSTRACT The aim of this work was to study, in glasshouse conditions, the effect of arbuscular mycorrhizal fungi (AMF) inoculation on plant growth and fruit quality of chili pepper cv. Cacho de Cabra when plants were transplanted to a sterile (SS) and unsterile substrate (NSS) composed by a mixture of soil-sand-vermiculite. Inocula were Glomus claroideum and a mixture of native HMA strains which were compared with a control. Twice a month, height and flower number and nutritional and chemical fruit characteristics were measured. In SS both HMA inocula increased shoot and root weight and diameter and weight of fruits. Maturation period was also reduced. Under the studied conditions the strains used showed compatibility with host plant which suggests that an effective inoculation of this vegetable could greatly improve its usefulness in industrial processes.
The effect of management systems and crop rotation on soil phosphorus (P) fractions and selected ... more The effect of management systems and crop rotation on soil phosphorus (P) fractions and selected soil properties were studied from 2002 to 2005 on an experiment established in 2001 in a volcanic derived Ultisol from southern Chile. Two tillage systems, no tillage (NT) and conventional tillage (CT), and two crop rotations, oat–wheat and white lupine–wheat were evaluated in order to
Total phosphorus (P), Olsen P, microbial P and different labile P fractions determined by a modif... more Total phosphorus (P), Olsen P, microbial P and different labile P fractions determined by a modified Hedley procedure, together to acid phosphatase (P-ase), pH and organic C, were analyzed in soil from four Nothofagus rainforest ecosystems differing in forest type and management. The sites included two evergreen (EF) and two secondary deciduous (DF) rainforests growing in an Andisol of southern Chile. Samples were collected from the organic layer and from mineral soil at 2–20 cm depth. Total P and phosphorus fractions were highest in evergreen forest soil with the predominance of moderate labile (NaOH–Po) fraction. Olsen P, microbial P, labile P fractions, inorganic P fractions and acid phosphatase were greater in the organic layer than the mineral soil, especially under evergreen forests. Evergreen forest litter affected P cycling enhancing P lability and P-ase activity in soil. Forest management affected P fractions in EF but not in DF forests, and generally did not modify soil properties. Results show that clearing of deciduous forest did not seriously affect the P cycle in this Andisol and confirm the fundamental role of the organic layer in P conservation of these ecosystems.
ABSTRACT Entre las diversas prácticas agrotecnológicas aplicables a sistemas agrícolas de baja in... more ABSTRACT Entre las diversas prácticas agrotecnológicas aplicables a sistemas agrícolas de baja inversión, se consideran la adición de residuos de plantas como una fuente de nutrientes, y el manejo adecuado de la simbiosis micorriza arbuscular (MA). Por ello, el objetivo general de este estudio fue determinar el efecto de la aplicación de residuos de cosecha e inoculación micorrízica sobre el desarrollo y nutrición mineral de plantas de trigo (Triticum aestivum L.) creciendo en un suelo ácido (Typic Distrandepts) y algunos parámetros químicos y biológicos del suelo. Residuos de lupino (Lupinus albus L.) y de trigo se adicionaron al suelo a una dosis equivalente a 6 Mg ha-1, sobre el cual se sembró trigo cv. Otto, con y sin inoculación de una cepa nativa de un hongo MA exógeno (Glomus etunicatum CH 110). La adición de residuos orgánicos incrementaron significativamente el rendimiento de materia seca en un 50-60% y la adquisición mineral de las plantas de trigo hasta en un 100%. Los residuos de trigo incrementaron el pH del suelo y la disponibilidad de P, mientras que los residuos de lupino incrementaron la colonización de hongos MA de 49 a 61%. La inoculación de un hongo MA exógeno disminuyó la adquisición de minerales, especialmente Al, lo que puede contribuir a la disminución de problemas de toxicidad en suelos ácidos.
The addition of plant residues and the appropriate management of arbuscular mycorrhizal (AM) symb... more The addition of plant residues and the appropriate management of arbuscular mycorrhizal (AM) symbioses have been tested in an acidic soil, an Andisol from Southern Chile, to ascertain whether these agro-technologies help plants to withstand potential mineral deficiency and the toxicities inherent to the low pH conditions. Firstly, the effects of legume (lupine) and non-legume (wheat) crop residues on some key root-soil interface activities (including AM development), on mineral acquisition by the plants, and on the yield of wheat growing in the test Andisol were investigated in a pot experiment under greenhouse conditions. Both lupine and wheat residues were added at a rate equivalent to 300 g m -2 to the natural soil. These organic amendments increased soil pH (wheat more than lupine), P availability and AM development (lupine more than wheat), plant performance and mineral acquisition (wheat more than lupine). Because of an increase in mycorrhizal activity, which appeared to be involved in the effect of the added crop (particularly lupine) residues, the role of the AM symbiosis was further investigated in a tailored inoculation assay, using a selected AM fungus (Glomus etunicatum), in interaction with lupine and wheat residues. A significant effect of AM inoculation on the reduction of Zn and Cu, and Mn and Al acquisition was demonstrated, which could be of interest in acid soils with regard to potential toxicity problems.
The aim of this work was to study the early influence of conventional tillage (CT) and no-tillage... more The aim of this work was to study the early influence of conventional tillage (CT) and no-tillage (NT) on arbuscular mycorrhizal fungal (AMF) propagules. A short 2-year-course crop rotation, i.e. trial consisting of a succession of wheat and oat, was studied in a typic Chilean Ultisol from the second to fourth year after the beginning of the experiment. Measurements included mycorrhizal characteristics and some soil properties in order to explain their influence on AMF propagules. Soil samples were taken yearly in autumn (fallow period) and in early spring (flowering). Significant differences in AMF hyphal length were observed between NT and CT in the first year, but such differences disappeared thereafter. No differences in metabolically active hyphae were obtained with wheat or oat under the two tillage systems. Mycorrhizal root colonization was always higher under NT than under CT. The number of AMF spores was also higher under NT than under CT, ranging from 158 to 641 spores per 100 cm 3 . Twenty-two AMF species including eight Glomus spp., six Acaulospora spp., four Scutellospora spp., one Archaeospora sp., one Diversispora sp., one Entrophospora sp. and one Pacispora sp. were observed in both agroecosystems. Higher spore number of Acaulospora spp. was found under wheat than under oat and under CT than under NT, whilst more spores of Scutellospora spp. were observed under NT than under CT. From all mycorrhizal characteristics, spore number could be visualized as an early and useful indicator of the effect of tillage systems on mycorrhizal propagules in short-term experiments.
... nearly all ecosystems, but the application of heavy doses of P fertilizer reduces the ... a r... more ... nearly all ecosystems, but the application of heavy doses of P fertilizer reduces the ... a reduction in mycorrhizal colonization resulted in a decrease of phosphorus absorption in ... Schenck, 1990]); consequently, deeper studies are required to understand these effects under natural ...
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Books by Rosa Rubio
Los contenidos reflejan, por una parte, el estado de la cuestión investigadora en materia de ciberperiodismo; por otra, la presencia en Internet de los medios locales en diversas CCAA españolas (Galicia, Cataluña, el País Vasco y la Comunidad Valenciana); y por último, el estudio de diversos casos prácticos que abarcan tanto el análisis de medios locales como confidenciales y weblogs.
Papers by Rosa Rubio
Los contenidos reflejan, por una parte, el estado de la cuestión investigadora en materia de ciberperiodismo; por otra, la presencia en Internet de los medios locales en diversas CCAA españolas (Galicia, Cataluña, el País Vasco y la Comunidad Valenciana); y por último, el estudio de diversos casos prácticos que abarcan tanto el análisis de medios locales como confidenciales y weblogs.