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La mancha de la hoja por Alternaria (ALT) y la mancha negra del tallo por Phoma (MNT) son enfermedades foliares endémicas del girasol en Argentina. MNT disminuye regularmente el rendimiento del girasol de alto potencial del sur de Buenos Aires. La variabilidad ambiental entre años y la fecha de siembra inciden en la ocurrencia de estas enfermedades, sin embargo, la información sobre su efecto es escasa. El objetivo de este trabajo fue evaluar la ocurrencia de estas enfermedades y su impacto sobre el rendimiento, el peso y número de aquenios y el contenido de aceite, en diferentes ambientes (años y fechas de siembra) del sur de Buenos Aires, Argentina. Se realizaron cinco experimentos en la Estación Experimental Agropecuaria del Instituto Nacional de Tecnología Agropecuaria en Balcarce en los años 2003, 2005, 2007, 2008 y 2009 en condiciones de campo e inoculación natural. Se evaluaron cinco híbridos, protegidos o no protegidos con una mezcla de fungicidas foliares. Tres experimentos incluyeron dos fechas de siembra (temprana y tardía). Se midió el área foliar, la incidencia y severidad de las enfermedades, el rendimiento, el peso y número de aquenios y el contenido de aceite. MNT fue la enfermedad de mayor prevalencia e incidencia (19 a 81%). Con menor frecuencia se observó presencia severa de ALT (0,3 a 10%) y ocurrencia atípica de roya negra por Puccinia helianthi (RN; 0 a 23%) en 2007. Las mayores precipitaciones y humedad relativa observadas en fechas de siembra tardías se correspondieron con aumento en la incidencia o severidad de síntomas (> 70%) principalmente de ALT. MNT, ALT y RN disminuyeron la duración del área foliar principalmente en hojas del estrato medio o superior, mientras que la protección con fungicidas redujo su efecto. MNT fue la enfermedad que más se asoció con la disminución del peso y número de aquenios. El contenido de aceite disminuyó en los tratamientos testigo en asociación con la siembra tardía y la presencia de ALT. El efecto de las enfermedades foliares sobre el rendimiento (11 a 17%), el peso y número de aquenios y el contenido de aceite varió con el ambiente de experimentación y en relación con la incidencia de MNT y la ocurrencia de epifitias severas de RN y ALT. La aplicación de fungicidas foliares mostró un beneficio productivo.

Conventional field phenotyping for drought tolerance, the most important factor limiting yield at a global scale, is labor-intensive and time-consuming. Automated greenhouse platforms can increase the precision and throughput of plant phenotyping and contribute to a faster release of drought tolerant varieties. The aim of this work was to establish a framework of analysis to identify early traits which could be efficiently measured in a greenhouse automated phenotyping platform, for predicting the drought tolerance of field grown soybean genotypes. A group of genotypes was evaluated, which showed variation in their drought susceptibility index (DSI) for final biomass and leaf area. A large number of traits were measured before and after the onset of a water deficit treatment, which were analyzed under several criteria: the significance of the regression with the DSI, phenotyping cost, earliness, and repeatability. The most efficient trait was found to be transpiration efficiency measured at 13 days after emergence. This trait was further tested in a second experiment with different water deficit intensities, and validated using a different set of genotypes against field data from a trial network in a third experiment. The framework applied in this work for assessing traits under different criteria could be helpful for selecting those most efficient for automated phenotyping.

Increased transpiration efficiency (the ratio of biomass to water transpired, TE) could lead to increased drought tolerance under some water deficit scenarios. Intrinsic (i.e., leaf-level) TE is usually considered as the primary source of variation in whole-plant TE, but empirical data usually contradict this assumption. Sunflower has a significant variability in TE, but a better knowledge of the effect of leaf and plant-level traits could be helpful to obtain more efficient genotypes for water use. The objective of this study was, therefore, to assess if genotypic variation in whole-plant TE is better related to leaf- or plant-level traits. Three experiments were conducted, aimed at verifying the existence of variability in whole-plant TE and whole-plant and leaf-level traits, and to assess their correlation. Sunflower public inbred lines and a segregating population of recombinant inbred lines were grown under controlled conditions and subjected to well-watered and water-deficit treatments. Significant genotypic variation was found for TE and related traits. These differences in whole-plant transpiration efficiency, both between genotypes and between plants within each genotype, showed no association to leaf-level traits, but were significantly and negatively correlated to biomass allocation to leaves and to the ratio of leaf area to total biomass. These associations are likely of a physiological origin, and not only a consequence of genetic linkage in the studied population. These results suggest that genotypic variation for biomass allocation could be potentially exploited as a source for increased transpiration efficiency in sunflower breeding programmes. It is also suggested that phenotyping for TE in this species should not be restricted to leaf-level measurements, but also include measurements of plant-level traits, especially those related to biomass allocation between photosynthetic and non-photosynthetic organs.

This paper focuses on current research on early colonisation of the Atlantic coast of South America during the early Holocene. We present advances in the investigation of raw material procurement at the Rincón de los Indios site, located in the eastern part of Uruguay. The technological studies suggest that some aspects of different styles of projectile points are related with environmental adaptation processes, experienced by the first American people in the New World. The occupation of new spaces and new forms of exploitation of resources changes the organisation of lithic technology. The distance to good quality rocks were critical for the opportunities and economic organisation of hunting groups. The study of changes in lithic procurement strategies for projectile points helps us develop a more comprehensive knowledge of this important social adaptation process which occurred during this period. These patterns started to become stabilised in the latter part of the early Holocene across the extended territory and confirm the efficient land occupation associated an intensive hunter-gatherer economies.

El sitio arqueológico Rincón de los Indios ha sido objeto de excavaciones desde 1995, en relación a los grupos constructores de cerritos. En los últimos años fue descubierto un nivel de ocupación delHoloceno Temprano. El presente trabajo da cuenta de ese nivel más antiguo, tanto a su ubicación estratigráfica, su edad y su industria lítica (ca 8.800 a 7100 a.P.). Entre las herramientas del sitio, algunas son expeditivas y multi propósito, mientras que hay una variedad de instrumentos formales como las puntas deproyectil. Los estudios tecnológicos y funcionales muestran un proceso de reciclaje de las puntas de proyectil, con transformaciones a lo largo de diversos itinerarios de vida.

The effect of night temperature during short periods in seed filling on oil tocopherol content and tocopherol/linoleic acid ratio was investigated in a traditional sunflower hybrid. Seeds were sown in the field at Balcarce on the 3rd and 22nd of November. In each experiment, treatments in which night temperature was increased at three consecutive periods of 200 °C day (base temperature: 6 °C) were applied.Tocopherol concentration was reduced when night temperature was increased early in seed filling. Such an increase could be attributed to a correlative increase in the daily average temperature, as no differences in tocopherol concentration were found when plants were cultivated in growth chambers under different day/night temperature but at the same daily average temperature. Temperature affected tocopherol concentration mainly by affecting the oil weight per seed.The tocopherol/linoleic acid ratio was not affected by temperature.

Tocopherols are natural antioxidants that increase the stability of food fat and fulfill an important biological requirement in humans. There are no previous studies on the variability of tocopherol concentration and composition in the oil of sunflower traditional hybrids (TH) and high oleic sunflower hybrids (HOH) from different environments in Argentina. The objective of this work was to detect and examine that variability. Seed samples were obtained from i) seven TH grown in four locations (Experiment I) and, ii) five hybrids (three HOH and two traditional ones) grown in three locations (Experiment II). Concentrations of total tocopherol in oil ranged from 634 to 1054 μg g oil–1. α-tocopherol accounted for 90.8 to 97% of the total tocopherols. Total and α-tocopherol concentrations were highly genetically determined (more than 80%). In Experiment I, a significant, although low in value, interaction between hybrid and location was found for total and α-tocopherol concentrations. In Experiment II, mean values for total tocopherol concentration in HOH and in each environment were larger than in TH. Significant differences for total and α-tocopherol concentration were not found among HOH and environments. The variation of tocopherol concentration for each hybrid across environments was higher than the variation among hybrids in the same environment. To obtain oil with high tocopherol concentration, both hybrid and environment must be selected.

Novalis, desconocido por los autores españoles del Romanticismo, fue sin embargo traducido por autores modernistas y difundido por los aficionados a la teosofía y otras doctrinas esotéricas pocos años antes de que comenzara a gestarse La lámpara maravillosa. Su Heinrich von Ofterdingen es título capital en la trayectoria de un subgénero narrativo y poetológico que convertía la Bildungsroman en «camino de perfección» estética. El problema planteado tantas veces por la crítica a propósito del género de La lámpara maravillosa puede explicarse en esta tradición. Valle, como Novalis, preparó en esta obra una poética mágica que coincide con la del alemán en todos sus puntos fundamentales.