Transformaciones en el uso de la tierra e impactos ambientales en el partido de Tandil, provincia de Buenos Aires, en el período 1988-2015

A partir de la década de los 80 y durante los últimos años se han registrado diversos cambios en los agroecosistemas pampeanos. De acuerdo a lo anterior, surge como objetivo analizar los cambios en el uso de la tierra del partido de Tandil en el período 1988 – 2015, y observar los impactos ambientales más relevantes asociados a las transformaciones agroproductivas. Para esto se utilizaron dos imágenes, una obtenida a partir de estudios previos, Landsat 5, y otra actual, Landsat 8. Se identificaron diferentes clases de uso del suelo: las tierras agrícolas se agruparon en áreas cultivables y cultivadas que aumentaron un 88,6%, mientras que las ganaderas en las áreas con pastizales y pasturas, disminuyeron un 56,9%; los cuerpos de agua se redujeron un 18,5% y las zonas urbanas se incrementaron un 94,6%. El uso y aplicación de imágenes satelitales, pueden ser una herramienta indispensable en el desarrollo de propuestas de gestión ambiental que conlleven a la sustentabilidad agroecológica.Since the 80´s and during recent years, some changes have been registered in the Pampean agroecosytems. According to the above, emerges as objective to analyze changes in land use of Tandil in the period 1988 - 2015, and observe the most relevant environmental impacts associated with agricultural production transformations. Different land use classes were identified: agricultural land were grouped into arable and cultivated areas increased by 88.6%, while livestock in areas of grasslands and pastures, decreased by 56.9%; further water bodies were reduced by 18.5% and urban areas increased by 94.6%. The use and application of satellite images can be an invaluable tool in the development of environmental management proposals that lead to the agro – ecological sustainability.Eje: A2: Paisajes, Territorios y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Transformaciones en el uso de la tierra e impactos ambientales en el partido de Tandil, provincia de Buenos Aires, en el período 1988-2015

A partir de la década de los 80 y durante los últimos años se han registrado diversos cambios en los agroecosistemas pampeanos. De acuerdo a lo anterior, surge como objetivo analizar los cambios en el uso de la tierra del partido de Tandil en el período 1988 – 2015, y observar los impactos ambientales más relevantes asociados a las transformaciones agroproductivas. Para esto se utilizaron dos imágenes, una obtenida a partir de estudios previos, Landsat 5, y otra actual, Landsat 8. Se identificaron diferentes clases de uso del suelo: las tierras agrícolas se agruparon en áreas cultivables y cultivadas que aumentaron un 88,6%, mientras que las ganaderas en las áreas con pastizales y pasturas, disminuyeron un 56,9%; los cuerpos de agua se redujeron un 18,5% y las zonas urbanas se incrementaron un 94,6%. El uso y aplicación de imágenes satelitales, pueden ser una herramienta indispensable en el desarrollo de propuestas de gestión ambiental que conlleven a la sustentabilidad agroecológica.Since the 80´s and during recent years, some changes have been registered in the Pampean agroecosytems. According to the above, emerges as objective to analyze changes in land use of Tandil in the period 1988 - 2015, and observe the most relevant environmental impacts associated with agricultural production transformations. Different land use classes were identified: agricultural land were grouped into arable and cultivated areas increased by 88.6%, while livestock in areas of grasslands and pastures, decreased by 56.9%; further water bodies were reduced by 18.5% and urban areas increased by 94.6%. The use and application of satellite images can be an invaluable tool in the development of environmental management proposals that lead to the agro – ecological sustainability.Eje: A2: Paisajes, Territorios y AgroecologíaFacultad de Ciencias Agrarias y Forestale

EXPERIENCIAS PRÁCTICAS DE LABORATORIO: USOS EDUCATIVOS DE SENSORES MULTIPARAMÉTRICOS ASISTIDOS POR COMPUTADORA

La articulación Ciencias Naturales y Tecnología, busca desarrollar y potenciar las habilidades, capacidades ycompetencias de los estudiantes, a través de la manipulación y destreza de diferentes instrumentos asociados a los procesos de estudio e investigación del complejo mundo natural. A partir de esto y desde los espacios curriculares: Historia y epistemología de la biología, Didáctica de las Ciencias Naturales y Taller de nuevas tecnologías, es que se diseñaron, propusieron y desarrollaron dos secuencias didácticas para un primer año del profesorado de Biología de Argentina. Se observó que la mayoría de los docentes participantes valoraron la interdisciplinariedad de la propuesta, el desarrollo de los experimentos y el proceso de análisis de los datos. Finalmente se rescató el importante rol que tiene la Tecnología en el estudio de las Ciencias Naturales

Variations of chemical composition and energy content in natural and genetically defined cultivars of Macrocystis from Chile

Seasonal and intra-thallus variations of energy content and chemical composition were assessed in an intertidal population of Macrocystis in southern Chile. Phylloid protein and lipid from cultured material were compared with seasonal variation in native Macrocystis. Furthermore, populations in northern and southern Chile and Falkland Islands were compared with various intra-/inter-cultivar genotypes of Chilean Macrocystis. Energetic values did not show seasonal or intra-thallus variations, with the exception of pneumatocysts, which had high levels of ash (49.9% DW) and low values of total energy (8.3% DW). Seasonal patterns were detected in protein and carbohydrate composition, with opposite trends. Likewise, holdfasts contained high amounts of protein (21.0% DW), and phylloids were high in soluble carbohydrates (4.5% DW). Lipids instead showed two peaks per year in an intertidal population and reached up to 0.4% DW. Alginic acid was the major organic compound in intertidal Macrocystis (46.8% DW), with differences on seasonal and intra-thallus levels. Mannitol content, in contrast, was erratic and lower than in other Laminariales (<5% DW). In general, protein and lipid content in our cultivars were 20% higher than in natural populations. Our experimental results indicate the possibility to manipulate the chemical composition of Macrocystis thalli through inter-/intra-specific crosses. This will be a basis, upon which selected genotypes can open new perspectives to Macrocystis mariculture industries in Chile

Utilization of holdfast fragments for vegetative propagation of Macrocystis integrifolia in Atacama, Northern Chile

We attempted to propagate Macrocystis integrifolia (giant kelp) by fragmentation and regeneration of holdfasts, which consist of creeping stolons with lateral haptera. Stolons from a natural kelp population in Bahia Chasco (Atacama, North Chile) were cut into fragments, each containing one or more lateral stipe and frond initials. Fragments were attached to longlines with elastic bands. We used two additional types of inoculants as controls: (1) natural recruits from the local parent population and (2) laboratory-cultured young sporophytes. Length, reproductive phenology, and mortality were determined monthly. Our results confirmed the feasibility of M. integrifolia propagation by reattachment of stolon fragments, and we obtained up to eight new individuals from one parent holdfast. Individuals from holdfast regeneration formed sporangial sori 3 months earlier than control specimens from recruits and laboratory culture, while all three types gave similar values for mortality. Holdfast morphology of regenerates differed strongly depending on their origin: stolon fragments continued growth and developed new haptera except in the cut surfaces, natural recruits formed typical M. integrifolia holdfast morphs, and sporophytes originating from laboratory culture produced minor stolons with many haptera. Implications of our results on ecology, repopulation, and aquaculture are discussed.publishe

Detection of citrus psorosis virus by RT-qPCR validated by diagnostic parameters

Citrus psorosis virus (CPsV) is the causal agent of psorosis, an important disease of citrus. Sanitary and certification programmes helped reduce disease damage caused by psorosis and other graft-transmissible diseases in many citrus-growing regions. For quarantine and certification programmes, most of these diseases are currently diagnosed using biological indexing (BI) on sensitive indicator plants. In the case of citrus psorosis, CPsV can be detected by molecular methods such as quantitative reverse transcription PCR (RT-qPCR), which is cheaper and faster than BI, but sensitivity, reliability, and reproducibility of both procedures have not been compared so far. In this work, 128 plants from Argentina and Uruguay were analysed using BI and CPsV detection by the RT-qPCR assay. Almost perfect agreement between both diagnostic procedures and sensitivity, specificity, and estimated likelihood ratios indicate that RT-qPCR is equivalent to BI for citrus psorosis diagnosis, thus providing confidence in the quick diagnostic procedure to monitor the sanitary status of citrus trees.Fil: Simeone, Melina Ailin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Gómez, Claudio. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Entre Rios. Estacion Experimental Agropecuaria Concordia.; ArgentinaFil: Bertalmío, Ana. Instituto Nacional de Investigación Agropecuaria; UruguayFil: Ruiz, María Esperanza. Universidad Nacional de La Plata. Facultad de Ciencas Exactas. Laboratorio de Investigación y Desarrollo de Bioactivos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Hauteville, Claudia. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Entre Rios. Estacion Experimental Agropecuaria Concordia.; ArgentinaFil: Godoy Suarez, Laura. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Entre Rios. Estacion Experimental Agropecuaria Concordia.; ArgentinaFil: Tito, Blas Alfredo. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Entre Rios. Estacion Experimental Agropecuaria Concordia.; ArgentinaFil: Garcia, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentin

Detection of citrus psorosis virus by RT-qPCR validated by diagnostic parameters

Citrus psorosis virus (CPsV) is the causal agent of psorosis, an important disease of citrus. Sanitary and certification programmes helped reduce disease damage caused by psorosis and other graft-transmissible diseases in many citrus-growing regions. For quarantine and certification programmes, most of these diseases are currently diagnosed using biological indexing (BI) on sensitive indicator plants. In the case of citrus psorosis, CPsV can be detected by molecular methods such as quantitative reverse transcription PCR (RT-qPCR), which is cheaper and faster than BI, but sensitivity, reliability, and reproducibility of both procedures have not been compared so far. In this work, 128 plants from Argentina and Uruguay were analysed using BI and CPsV detection by the RT-qPCR assay. Almost perfect agreement between both diagnostic procedures and sensitivity, specificity, and estimated likelihood ratios indicate that RT-qPCR is equivalent to BI for citrus psorosis diagnosis, thus providing confidence in the quick diagnostic procedure to monitor the sanitary status of citrus trees.Fil: Simeone, Melina Ailin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Gómez, Claudio. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Entre Rios. Estacion Experimental Agropecuaria Concordia.; ArgentinaFil: Bertalmío, Ana. Instituto Nacional de Investigación Agropecuaria; UruguayFil: Ruiz, María Esperanza. Universidad Nacional de La Plata. Facultad de Ciencas Exactas. Laboratorio de Investigación y Desarrollo de Bioactivos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Hauteville, Claudia. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Entre Rios. Estacion Experimental Agropecuaria Concordia.; ArgentinaFil: Godoy Suarez, Laura. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Entre Rios. Estacion Experimental Agropecuaria Concordia.; ArgentinaFil: Tito, Blas Alfredo. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Entre Rios. Estacion Experimental Agropecuaria Concordia.; ArgentinaFil: Garcia, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; Argentin

Stress-induced expression of IPT gene in transgenic wheat reduces grain yield penalty under drought

Background: The heterologous expression of isopentenyl transferase (IPT) under the transcriptional control of the senescence-associated receptor-like kinase (SARK) promoter delayed cellular senescence and, through it, increased drought tolerance in plants. To evaluate the effect of pSARK::IPT expression in bread wheat, six independent transgenic events were obtained through the biolistic method and evaluated transgene expression, phenology, grain yield and physiological biomass components in plants grown under both drought and well-irrigating conditions. Experiments were performed at different levels: (i) pots and (ii) microplots inside a biosafety greenhouse, as well as under (iii) field conditions. Results: Two transgenic events, called TR1 and TR4, outperformed the wild-type control under drought conditions. Transgenic plants showed higher yield under both greenhouse and field conditions, which was positively correlated to grain number (given by more spikes and grains per spike) than wild type. Interestingly, this yield advantage of the transgenic events was observed under both drought and well-watered conditions. Conclusions: The results obtained allow us to conclude that the SARK promoter-regulated expression of the IPT gene in bread wheat not only reduced the yield penalty produced by water stress but also led to improved productivity under well-watered conditions.EEA PergaminoFil: Beznec, Ailin. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; ArgentinaFil: Faccio, Paula Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; ArgentinaFil: Miralles, Daniel. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Cerealicultura; ArgentinaFil: Miralles, Daniel. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura (IFEVA); ArgentinaFil: Abeledo, Leonor G. Universidad de Buenos Aires. Facultad de Agronomía. Cátedra de Cerealicultura; ArgentinaFil: Décima Oneto, Cecilia Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Balcarce. Laboratorio de Agrobiotecnología; ArgentinaFil: Décima Oneto, Cecilia Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garibotto, María De Belén. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; ArgentinaFil: Garibotto, María De Belén. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gonzalez, Germán Andrés. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave; ArgentinaFil: Moreyra, Federico. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bordenave; ArgentinaFil: Elizondo, Matias. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; ArgentinaFil: Elizondo, Matias. Universidad Nacional de San Juan. Facultad de Ingeniería. Departamento de Agronomía. Unidad Integrada INTA-UNSJ; ArgentinaFil: Ruiz, Mónica Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; ArgentinaFil: Ruiz, Mónica Beatriz. Universidad Nacional de San Juan. Facultad de Ingeniería. Departamento de Agronomía. Unidad Integrada INTA-UNSJ; ArgentinaFil: Lewi, Dalia Marcela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; ArgentinaFil: Blumwald, Eduardo. University of California. Department of Plant Sciences; Estados UnidosFil: Llorente, Berta. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Diaz Paleo, Antonio Horacio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Pergamino. Sección Laboratorio Biotecnología; ArgentinaFil: Bossio, Adrian Ezequiel. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; Argentin