Search

Here, we compare arbuscular mycorrhizal fungi (AMF) communities and fatty acids in soils underdifferent no-till (NT) agricultural managements over two seasons in two consecutive years. Two NTpractices with different agricultural managements were compared: crop rotation (CR) and soya beanmonoculture (MC). Soils of natural grasslands (NG) were used as a reference. Treatments were testedalong a regional gradient (four geographical locations) across a 400-km transect of the ArgentineanPampas. We identified 46 morphospecies. Several morphospecies occurred abundantly at all soils;others appeared to be restricted to specific situations. At the regional scale, CR maintained the samerichness levels of AMF spores, whereas MC showed less richness, when compared with the NG.Although AMF spore density was clearly affected by cropping practices in the four locations, wecould observe some changes in AMF species richness, and similar diversity under agricultural andnatural soils. Fatty acid concentrations (whole-cell, phospholipid and neutral lipid fatty acids)revealed differences between soil managements and showed similar patterns of variation in alllocations. Spore density positively correlated with all soil lipids fractions. The results suggest thatAMF spore communities and fatty acids in soils are suitable indicators of soil management involvingdifferent levels of crop rotation. Spore richness measured at a regional scale proved to be sensitive todifferent NT agricultural management. Moreover, certain morphospecies could be good bioindicatorsfor NT practices based on cropping systems on the Argentinean Pampas. Fil: Cofré, María Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Ferrari, A. E.. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Bioquímica, Microbiología e Interacciones Biologicas en Suelo; Argentina Fil: Becerra, Alejandra Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Dominguez, L.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Wall, Luis Gabriel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Bioquímica, Microbiología e Interacciones Biologicas en Suelo; Argentina Fil: Urcelay, Roberto Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

Atriplex cordobensis occurs in salt works and saline soils of northern and central Argentina and is utilized as a forage source; however the mycorrhizal status of this salt bush is unknown. We studied the arbuscular mycorrhizae fungi (AMF) and dark-septate endophytes (DSE) fungi in A. cordobensis analysing infection of the roots and spores in the rhizopheric soil. Soil and root samples were collected during summer 2008 at three different saline sites (Salinas Grandes de Jujuy (SGJ), Quebrada de Cafayate-Salta (QCS) and Salinas Grandes de Córdoba (SGC). Assessment of AMF and DSE colonization were made by washing and staining the roots and the AMF spores number was estimated by standard sieving and decanting methods. The results showed moderate to high levels of AMF colonization as well as significant differences in AM colonization and AMF spores number between sites. Glomus s.l. was the dominant genus in A. cordobensis rhizosphere. DSE colonization did not show significant differences between sites. This study confirmed the occurrence of AMF and DSE in Atriplex cordobensis in stressed environments of Argentina. Fil: Cofré, María Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Becerra, Alejandra Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Nouhra, Eduardo Ramon. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Soteras, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina

The objective of this study was to determine patterns of arbuscular mycorrhizal (AM) colonization of Alnus acuminate Kunth at two natural forests in relation to soil parameters at two different seasons (autumn and spring). The soil parameters studied were field capacity, pH, electrical conductivity, available P, total N and organic matter. The percentage of AM colonization was estimated and correlated to soil properties and to two different seasons. The results indicate that the percentage of AM colonization varied among soil types and was higher in spring than autumn. A significant positive correlation was found between AM colonization and electrical conductivity, organic matter and total Nitrogen. Results of this study provide evidence that AM colonization of A. acuminata can be affected by some soil parameters and seasonality. Key words. Alnus, arbuscular mycorrhizal, seasonality, soil type, Yunga forest. Fil: Becerra, Alejandra Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Arrigo, Nilda Marta. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Recursos Naturales y Ambiente. Cátedra de Edafologia; Argentina Fil: Bartoloni, Norberto Jose. Universidad de Buenos Aires; Argentina Fil: Dominguez, Laura Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina Fil: Cofré, María Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina