Abstract:

The growing collection of sequenced or genotyped Arabidopsis thaliana accessions includes mostly individuals from the native Eurasian and N. African range and introduced North American populations. Here, we describe the genetic and phenotypic diversity, along with habitats and life history, of A. thaliana plants collected at the southernmost end of its worldwide distribution. Seed samples were harvested from plants growing in four sites within a ~3500-km2-area in Patagonia, Argentina, and represent the first germplasm to be collected in South America for this species. Whole-genome resequencing revealed that plants from the four sites and a Patagonia herbarium specimen collected in 1967 formed a single haplogroup (Pat), indicating that the phenotypic variation observed in the field reflected plastic responses to the environment. admixture and principal components analyses suggest that the ancestor of the Pat haplogroup either came from Italy or the Balkan/Caucasus regions of Eurasia. In the laboratory, plants from the Pat haplogroup were hyposensitive to continuous red (Rc) and shade light, with corresponding changes in the expression of phytochrome signalling genes. Pat had higher PIF3 and PIF5 and lower HY5 expression under Rc light; and lower expression of PIL1, ATHB2 and HFR1 under shade compared to Col-0. In addition, Pat plants had a strong vernalization requirement associated with high levels of FLC expression. We conclude that including Pat in studies of natural variation and in comparison with other introduced populations will provide additional information for association studies and allow for a more detailed assessment of the demographic events following colonization.

Author affiliation: Kasulin, Luciana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina

Author affiliation: Rowan, Beth A.. Max Planck Institute for Developmental Biology; Alemania

Author affiliation: Leon, Rolando Juan Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina

Author affiliation: Schuenemann, Verena J.. University of Tübingen; Alemania

Author affiliation: Weigel, Detlef. Max Planck Institute for Developmental Biology; Alemania

Author affiliation: Botto, Javier Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía; Argentina

Abstract:

El objetivo de este trabajo fue evaluar el efecto de las variables internas y externas sobre la abundancia de <i>Mus musculus</i> en granjas avícolas. Consideramos como variables “internas” a aquellas características asociadas al estado de mantenimiento de la granja y a su infraestructura, y como “externas” o “espaciales” a aquellas que dependieron de la ubicación de la granja respecto a otras granjas y, por lo tanto, relacionadas a la probabilidad de invasión por roedores. El trabajo se desarrolló en diciembre 2004, enero, septiembre, octubre y diciembre de 2005 en granjas avícolas del Partido de Exaltación de la Cruz (Provincia de Buenos Aires, Argentina). El “estado de la granja” mostró una relación negativa con la abundancia de <i>M. musculus</i>, mientras que las otras variables fueron no significativas. No se observó concordancia entre el agrupamiento de granjas teniendo en cuenta distancias geográficas y esfuerzo de captura, ni autocorrelación espacial de la abundancia. La abundancia de <i>M. musculus</i> en las granjas avícolas estudiadas dependería de los efectos internos y no de los externos, por lo que el mantenimiento de las poblaciones dependería de una dinámica “in situ” y no del ingreso de individuos desde sitios vecinos, aunque también podría haber transporte pasivo por el hombre.

The aim of this paper was to assess the effects of the internal and spatial (external) variables on the abundance of <i>Mus musculus</i> in poultry farms. The internal variables were the maintenance conditions of the farms and the number of sheds, while the external variables were related to the spatial location of each farm with respect to other farms and thus, to the probability of invasion from surrounding areas. This work was conducted on December 2004, January, September, October and December 2005 at poultry farms located at Exaltación de la Cruz, Buenos Aires Province, Argentina. If the abundance is mainly determined by the re-colonization through the displacement of the individuals, we expected the abundance of <i>M. musculus</i> to show an inverted relationship with the distance between farms; the abundance of <i>M. musculus</i> to show a positive relationship with the number of neighboring farms; as well as a correlation among the differences in abundance and the geographical distances between farms. We also expected the abundance of <i>M. musculus</i> to show a negative relationship with the farm maintenance condition, and a positive relationship with the number of sheds present in the farm. The only variable related to the variation in the abundance of M. musculus among farms was the maintenance condition, suggesting that the dynamics of this species in each farm is independent of the abundance in other farms, and does not depend on movements from their neighborhoods. The persistence of the population could be due to its recovery starting from the individuals who survived to the treatment that is permanently done in the farms, favored perhaps by a dense-dependent response of the reproduction or to the passive re-colonization through men.

Abstract:

In this article the theoretical aspects are developed from a historic-anthropological perspective, which anticipates a frontier space with a differentiated economic, social and cultural structure, where they operate the life and experiences of families of settlers who are 90 km of the Northern territorial limit controlled by the Government of the province of Santa Fe. In the north border of Santa Fe the "desert" fights", first, with the foundation of agricultural colonies for contract and, then, with the military advance. Therefore, the concept of border of colonization is chosen to analyze the role of the colonies that make it up next to Alexandra Colony. Based on the review of the studies of border, focuses on the character resilient of social groups facing out of the last line of forts to the North of the province of Santa Fe, where the agricultural colonies were founded.

En este artículo se desarrollan los aspectos teóricos desde una perspectiva histórico-antropológica, que anticipa un espacio fronterizo con una diferenciada estructura económica, social y cultural, donde se desenvuelven la vida y experiencias de familias de colonos que se instalan a 90 km del límite territorial septentrional controlado por el gobierno de la Provincia de Santa Fe. En la frontera norte de Santa Fe se combate el “desierto”, en primer lugar, con la fundación de colonias agrícolas por contrato y, luego, con el avance militar. Por lo que se elige el concepto de frontera de colonización para analizar el rol de las colonias que junto a Alexandra Colony la conforman. Partiendo de la revisión de los estudios de frontera, se focaliza en el carácter resiliente de los grupos sociales enfrentados por fuera de la última línea de fortines al norte de la Provincia de Santa Fe donde se fundan colonias agrícolas.

Author affiliation: Dosztal, Irene. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Investigaciones Socio-Históricas Regionales. Centro de Estudios Sociales Regionales - Nodo Cesor - Ishir; Argentina

Abstract:

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.

Author affiliation: 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

Author affiliation: 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

Author affiliation: 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

Author affiliation: 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

Abstract:

In Argentina the Yungas forests are among the ecosystems most affected by human activity, with loss of biodiversity. To assess the arbuscular mycorrhizal (AM) colonization and the arbuscular mycorrhizal fungi (AMF) spore numbers in these ecosystems, the roots of the most dominant native plants (one tree, Alnus acuminata; three herbaceous, Duchesnea indica, Oxalis conorrhiza, Trifolium aff. repens; and one shrub, Sambucus peruviana) were studied throughout the year from two sites of Yungas forests. Assessments of mycorrhizal colonization (percent root length, intraradical structures) were made by washing and staining the roots. Soil samples of each plant species were pooled and subsamples were obtained to determine AM spore numbers. The herbaceous species formed both Arum- and Paris-type morphologies, whereas the tree and the shrub species formed respectively single structural types of Arum-and Paris-type. AM colonization, intraradical fungi structures and AMF spore numbers displayed variation in species, seasons and sites. D. indica showed the highest AM colonization, whereas the highest spore numbers was observed in the rhizosphere of A. acuminata. No correlation was observed between spore numbers and root length percentage colonized by AM fungi. Results of this study showed that Alnus acuminata is facultatively AM. The AM colonization, intraradical fungi structures and AMF spore numbers varied in species depending on phenological, climatic and edaphic conditions.

Author affiliation: 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

Author affiliation: Cabello, Marta Noemí. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Instituto de Botánica Spegazzini; Argentina

Author affiliation: Zak, Marcelo Román. 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

Author affiliation: Bartoloni, Norberto Jose. Universidad de Buenos Aires. Facultad de Agronomía; Argentina

Abstract:

Author affiliation: Becerra, Alejandra C.. Instituto Multidisciplinario de Biología Vegetal. Cátedra de Diversidad Vegetal I. Facultad de Ciencias Exactas, Físicas y Naturales. Universidad Nacional de Córdoba; Argentina

Author affiliation: Cabello, Marta Noemí. División Instituto Spegazzini. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentina

Author affiliation: Zak, Marcelo R.. Universidad Nacional de Córdoba; Argentina

Author affiliation: Bartoloni, Norberto José. Cátedra de Métodos Cuantitativos Aplicados. Facultad de Agronomía. Universidad de Buenos Aires; Argentina

Abstract:

The aim of this work was to describe and compare the arbuscular mycorrhizal fungal (AMF) morphospecies community and root colonization in three Polylepis australis forest disturbance types (degraded forest, young forest and mature forest). Rhizosphere soil samples were collected during wet and dry seasons in three sites located at the high mountains of central Argentina. A highly diverse AMF community was detected with 32 different morphospecies. AMF richness, density, Shannon diversity and evenness were neither influenced by forest disturbance type nor by season. Nevertheless, indicator species analyses showed two AMF taxa mostly associated with the degraded forest, one with the young forest and two linked preferentially to the mature forest. Moreover, the latter forest type showed the highest biovolume of Gigaspora spp., a genus representative of conserved ecosystems. P. australis root colonization was similar among forest disturbance types and seasons. However, higher abundance of vesicles was observed during the dry than during the wet season. This study showed that AMF community composition was relatively similar among forests with distinct structural complexity. These results suggest that the AMF community may be resistant to the kind of disturbances that shaped the forests compared, or that natural successional processes may permit AMF to recover from these disturbances.

Author affiliation: Soteras, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba; Argentina

Author affiliation: Grilli, Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba; Argentina

Author affiliation: Cofré, María Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba; Argentina

Author affiliation: Marro, Nicolás Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba; Argentina

Author affiliation: Becerra, Alejandra Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba; Argentina

Abstract:

Glyphosate is a systemic non-selective herbicide, the most widely used in the world. Alongside with itsuse in agricultural and forestry systems, this herbicide is used in grasslands in late summer with theaim of promoting winter species with the consequent increase in stocking rate. However, its effects onnon-target organisms, such as arbuscular mycorrhizal fungi (AMF), are unclear. Arbuscular mycorrhizalfungi (AMF) colonize the root of more than 80% of terrestrial plants, improving their growth and survival,and therefore playing a key role in ecosystem structure and function. The aim of this work was to inves-tigate the possible pathways through which glyphosate application affects AMF spores viability and rootcolonization in grassland communities. Our hypothesis is that glyphosate application can damage AMFdirectly (through contact with spores and external hyphae) or indirectly through the changes it generateson host plants. The experiment had a factorial array with three factors: (1) plant species, at two levels(Paspalum dilatatum and Lotus tenuis), (2) doses of glyphosate, at three levels (0 l ha−1, 0.8 l ha−1and 3 l ha−1), and (3) application site, at two levels: soil (direct pathway) and plant foliage (indirect pathway).Spore viability was reduced even under the lowest glyphosate rate, but only when it was applied on thesoil. Total root colonization for both species was similarly decreased when glyphosate was applied toplant foliage or on soil, with no difference between 0.8 and 3 l ha−1. The number of arbuscules was 20%lower when glyphosate was applied on plant foliage, than when it was applied on the soil. Our findingsillustrate that glyphosate application negatively affects AMF functionality in grasslands, due to differentcauses depending on the herbicide application site. While, under field conditions, the occurrence of directand/or indirect pathways will depend on the plant cover at the time of glyphosate application, the con-sequences of this practice on the plant community structure will vary with the mycorrhizal dependenceof the species composition regardless of the pathway involved.

Author affiliation: Druille, Magdalena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina

Author affiliation: Omacini, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina

Author affiliation: Golluscio, Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina

Author affiliation: Cabello, Marta Noemi. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. Instituto de Botánica Spegazzini; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina

Abstract:

Author affiliation: Druille, Magdalena. IFEVA. Faculty of Agronomy. University of Buenos Aires; Argentina

Author affiliation: Omacini, Marina. IFEVA. Faculty of Agronomy. University of Buenos Aires; Argentina

Author affiliation: Golluscio, Rodolfo A.. IFEVA. Faculty of Agronomy. University of Buenos Aires; Argentina

Author affiliation: Cabello, Marta Noemí. Instituto Spegazzini. Faculty of Natural Sciences and Museum. National University of La Plata; Argentina

Abstract:

Polylepis australis trees endemic to Argentina dominate the canopy of subtropical high altitude forests. Here, livestock rearing is the main economic activity and is suspect of the low performance of P. australis trees through direct and indirect effects which could include the reduction in arbuscular mycorrhizal fungi (AMF) and their benefit to trees. To elucidate the role of AMF, we compare plant performance indicators, arbuscular mycorrhizal (AM) colonization and AMF communities in 20 trees distributed in two areas of central Argentina which differed in livestock grazing intensity. The area with high livestock density presented more soil degradation and trees with a lower overall plant performance than the area with reduced livestock density. The AM colonization values of P. australis were considerably higher than reported for other tree species and the area with high livestock density had a lower proportion of arbuscules and higher proportion of hyphae, while vesicles and AM colonization -all structure considered together- did not differ between areas. Overall AMF spore number and of most species when considered separately was significantly higher in the area with high livestock density, suggesting a high tolerance and adaptation of AMF to livestock. We conclude that a reduction in livestock improves the performance of P. australis, that this improvement could be mediated by an increase in the proportion of arbuscules, but there does not appear to be any limitation in AM colonization or AMF spore number which could otherwise be limiting forest restoration.

Author affiliation: Menoyo, Eugenia. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Renison, Daniel. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: 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