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BACKGROUND: This study characterized the influence of temperature during grain filling on the saturated fatty acid distribution in triacylglycerol molecules from high stearic sunflower lines with different genetic backgrounds. Two growth chamber experiments were conducted with day/night temperatures of 16/16, 26/16, 26/26 and 32/26 °C. Fil: Izquierdo, Natalia Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Cátedra de Fisiología Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Martínez Force, Enrique. Consejo Superior de Investigaciones Científicas; España Fil: Garcés, Rafael. Consejo Superior de Investigaciones Científicas; España Fil: Aguirrezábal, Luis Adolfo Nazareno. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias. Cátedra de Fisiología Vegetal; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Zambelli, Andres Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Centro de Investigaciones Biotecnológicas; Argentina Fil: Reid, Roberto. Centro de Investigaciones Biotecnológicas; Argentina

The oil industry demands sunflower oils with high oleic acid content. New varieties producing high oleic oils independently of the growing environment are needed as growers could receive an extra prime for offering them. Oil fatty acid composition of high oleic sunflower hybrids currently available carrying the Pervenets mutation could however be affected by the temperature during the grain filling period. A new high oleic mutation has been obtained to attain oils with ultra-high oleic levels (>90%oleic acid content). This new structural mutation would be able to reduce the variation in oleic acid percentage to changes in the minimum night temperature (MNT). The aim of this work was to assess the response of oil fatty acid composition of the new high oleic mutation to MNT compared to traditional and Pervenets genotypes. Field experiments in different sowing dates and locations and one growth chambers experiment were performed to explore a wide range of temperatures (11.8-23.2°C) during grain filling. The oleic acid percentage in traditional and high oleic Pervenets genotypes varied between 15.0-50.9% and 87.4-91.2%, respectively, while the new mutation genotype presented values of oleic acid between 91.3 and 92.5%. Moreover, the oleic acid percentage of traditional and Pervenets genotypes showed a linear and positive response to temperature (slopes 2.95 and 0.28%oleic acid °C-1, respectively). No response to temperature was detected in the new mutation genotype. The ultra-high oleic quality from the new high oleic sunflower mutant could be obtained in a wide range of environments as the fatty acid composition was not affected by temperature during grain filling, representing an advantage over the high oleic Pervenets and traditional genotypes. Fil: Alberio, Constanza. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; Argentina Fil: Izquierdo, Natalia Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata; Argentina Fil: Galella, Teresa. Advanta Semillas S.A.I.C.; Argentina Fil: Zuil, Sebastian. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Reconquista; Argentina Fil: Reid, Roberto. Advanta Semillas S.A.I.C.; Argentina Fil: Zambelli, Andres Daniel. Advanta Semillas S.A.I.C.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Aguirrezábal, Luis Adolfo Nazareno. Universidad Nacional de Mar del Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

En este trabajo se presenta un estudio que tiene como objetivo evaluar el conocimiento geométrico sobre cuadriláteros a través de los Niveles de Van Hiele. Participan en esta investigación estudiantes de sexto de primaria de centros educativos de Sevilla (España) y Liverpool (Reino Unido). La recogida de información se ha llevado a cabo a través de un cuestionario adaptado al nivel educativo de los estudiantes. Tras analizar y evaluar las respuestas de los estudiantes, se han comparado los resultados entre Sevilla y Liverpool. La información obtenida complementa los resultados obtenidos en una investigación llevada a cabo en 2013, permitiendo ofrecer una panorámica del conocimiento geométrico desde Educación Primaria hasta la Universidad. Aunque el proceso de adquisición del conocimiento geométrico es gradual, este no es suficiente para la formación de futuros maestros This paper presents a study whose aim is to evaluate the geometry knowledge about quadrilaterals through Van Hiele levels. In this research, the participants are Year-6 students of schools from Seville (Spain) and from Liverpool (United Kingdom). The data collection is made through a questionnaire adapted to the students. Having analysed and evaluated, the results of Seville are compared with these ones from Liverpool. The information provided complements the results obtained in a research of 2013, giving a view of the geometry knowledge from Primary Education to the University. Although the acquisition of the geometry knowledge is gradual, this is not enough for training future teachers Universidad de Sevilla. Grado en Educación Primaria

42 Páginas; 5 Figuras; 5 Tablas, BACKGROUND This study characterized the influence of temperature during grain filling on the saturated fatty acid distribution in triacylglycerol molecules from high stearic sunflower lines with different genetic backgrounds. Two growth chamber experiments were conducted with day/night temperatures of 16/16, 26/16, 26/26 and 32/26 °C. RESULTS In all genotypes, independently of the genetic background, higher temperatures increased palmitic and oleic acid and reduced linoleic acid concentrations. Increasing night temperature produced an increase in saturated-unsaturated-saturated species, indicating a more symmetrical distribution of saturated fatty acids. The solid fat index was more affected by temperature during grain filling in lines with high linoleic than high oleic background. Higher variations in symmetry among night temperatures were observed in lines with high oleic background, which are more stable in fatty acid composition. CONCLUSION The effect of temperature on triacylglycerol composition is not completely explained by its effect on fatty acid composition. Thus night temperature affects oil properties via its effects on fatty acid synthesis and on the distribution of fatty acids in the triacylglycerol molecules. © 2016 Society of Chemical Industry, This work was supported by the Instituto Nacional de Tecnología Agropecuaria (INTA, PNCYO 1127042), Universidad Nacional de Mar del Plata (UNMdP, AGR 406/13), Advanta Semillas SAIC, and Spanish Ministerio de Economía y Competitividad and FEDER (Project AGL2011-23187). We thank Luis Mendez for technical assistance during the experiments.

Several apoplastic enzymes have been implicated in the control of elongation growth of plant cells. Among them, peroxidases contribute to both loosening and stiffening of the cell wall. They appear to be regulated by various mechanisms, including the action of extracellular inhibitors. To obtain evidence of the role of the enzyme-inhibitor interaction during leaf development, the intercellular washing fluids from Helianthus annuus leaves of different ages were isolated using standard methods of vacuum infiltration and centrifugation. Peroxidase activities, assessed using tetramethylbenzidine as substrate, increased during leaf development, reaching a maximum value after the leaves were fully expanded. An inhibitor, chemically characterised as ascorbate, co-localised with the enzyme in the apoplast. Moreover, there was a strong negative correlation between the action of peroxidase and the micromolar concentration of ascorbate in the apoplastic fluid. The results show that in growing leaves, the in planta ascorbate concentration is able to restrain peroxidase enzyme activity. Then, at the time of growth cessation, the loss of extracellular ascorbate relieves the inhibition on this enzyme that contributes to wall fixation.

Fatty acid composition of Helianthus annuus L. (sunflower) oil depends on intercepted solar radiation per plant (ISR) during grain filling. This effect could be accounted for by the assimilate availability of the grains (the source-sink ratio). However, the current physiological-biochemical knowledge does not consider any effect of carbon availability on oil fatty acid composition. The objective of this work was to address the regulation of fatty acid composition by assimilate supply to sunflower grains. A wide range of source-sink ratios was obtained by manipulating either the source or the sink during grain filling. Assimilate supply was also modified by injecting sucrose into the receptacle of sunflower capitula. Grain weight and oil content depended on both ISR and source-sink ratio in a curvilinear manner. When sink size was decreased by grain excision, ISR failed to explain oil fatty acid composition, while source-sink ratio appropriately described it. Sucrose injection significantly increased grain weight, oil content, and oleic acid percentage of shaded plants. It is concluded that effects of ISR on fatty acid composition are a consequence of changes in assimilate availability for grain oil synthesis. To explain these results a conceptual model is proposed: when assimilate supply limits grain growth and oil synthesis, mainly linoleic acid is synthesized. As the assimilate supply increases, oleic acid desaturation process gets saturated and oleic acid accumulates.

Oil fatty acid composition of traditional genotypes of several crops including maize and soybean is affected by intercepted solar radiation per plant and temperature during grain filling. The effect of intercepted radiation on oil fatty acid composition of genotypes with increased oleic acid percentage of maize and soybean is unknown. Likewise, on such kind of maize genotypes, no studies have been performed about the effect of temperature on the oleic acid percentage. The objective of this work was to investigate and model the effect of intercepted solar radiation per plant and daily mean temperature during grain filling on the oleic acid percentage in the oil of maize and soybean genotypes with increased oleic acid grown under non limiting conditions. Field experiments were conducted in Balcarce and Cordoba in two growing seasons. An experiment with maize genotypes was also conducted in two sowing dates in Pergamino. The effect of intercepted solar radiation during grain filling on oil fatty acid composition was studied by shading and thinning plants. To evaluate the effect of daily mean temperature, plants were exposed to different temperatures during grain filling in two experiments performed in greenhouse and growth chambers. At harvest oil fatty acid composition was determined by gas–liquid chromatography. Intercepted solar radiation per plant or temperature increased the oleic acid percentage between 9 and 30 percentage points depending on the species and genotype. In both species, genotypes with increased oleic acid percentage presented a higher sensitivity of oleic acid percentage to variations in intercepted solar radiation than traditional ones. The effect of temperature on oil fatty acid composition was also higher in maize genotypes with increased oleic acid percentage than in the traditional one of the same species. In soybean, the sensitivity of oleic acid percentage to temperature was higher in one genotype and lower in the other as compared to the traditional one. Oleic acid percentage was linearly related to DMT but curvilinearly related to ISR per plant, reaching a maximum concentration of this fatty acid at high levels of irradiance. For both species, models that consider the additive effects of intercepted solar radiation and temperature were established. Predictions of the models were validated with data from six field independent experiments. The models adequately estimated ( r 2 ≥ 0.65) the oleic acid percentage of these genotypes grown under different temperatures and ISR per plant during grain filling from these experiments. These results could help to identify crop management practices (e.g. sowing dates, locations, sowing density), in the view to obtain a given oil quality when growing maize and soybean with increased oleic acid percentage.

Oil fatty acid composition of sunflower ( Helianthus annuus L.) closely depends on the environmental conditions during grain filling. Temperature and solar radiation are main environmental factors driving oil chemical composition, as revealed by experiments in which the effects of these variables were investigated separately. The present work aims at investigating whether both temperature and irradiance act independently or they interact in exerting their effects on oleic acid percentage of sunflower oil. With this purpose, minimum night temperature (MNT) and intercepted solar radiation (ISR) per plant were together modified during the grain filling period of the traditional sunflower hybrid ACA 885. Two experimental approaches were performed: (a) radiation was modified in three locations at different latitudes (location × radiation experiments), (b) radiation and temperature were modified in a factorial design within one location by using field shelters ( in situ temperature × radiation experiments). Regardless location or year effect, oleic acid percentage increased with ISR per plant up to a maximum value, which depended on MNT. In situ temperature × radiation experiments showed that plant heating increased oleic acid percentage under any radiation condition assayed, while plant shading produced a drop in oleic acid that was independent of MNT. Statistically significant interaction between MNT and ISR per plant was not detected. A mathematical relationship that considered that MNT and ISR per plant additively contribute to oleic acid percentage was established and verified using data from location × radiation experiments. This equation predicted well independent experimental data from in situ temperature × radiation experiments. Results obtained in this work could improve model prediction of oil quality of sunflower grown under different environmental conditions, and contribute to unravel the mechanisms underlying oleic acid percentage in sunflower oil.

Solar radiation intercepted during grain filling affects growth of grain crops. Its effects on oil fatty acid composition have not been investigated. The objective of this work was to investigate the effect of intercepted solar radiation per plant on oil fatty acid composition in four crops. An experiment including a cultivar of soybean, maize and sunflower was sown at Balcarce, Argentina, during two growing seasons (2001–02 and 2004–05) and two experiments with a rape cultivar were conducted during in 2004 and 2005. The amount of intercepted solar radiation during grain filling was modified by shading (50–80%) and thinning plants (50%). In addition, the same cultivars of soybean and maize were sown in the field at Parana, Argentina, during the 2004–05 growing season and in growth chambers under different day/night temperatures during grain filling. Regardless of the species, oleic acid percentage increased as intercepted solar radiation (ISR) per plant increased. The highest difference (13%) was observed in sunflower (shading vs. thinning) and the increase in oleic acid was associated with a reduction in both linoleic and linolenic acids. Saturated fatty acid percentage was not affected by intercepted solar radiation per plant. Differences among radiation treatments were observed not only at physiological maturity but also at earlier stages of the grain filling period. In soybean and maize, increasing daily mean temperature increased oleic acid percentage ( r 2 ≥ 0.52). Changes in fatty acid composition in radiation experiments and treatments were not accounted for by variations in temperature (differences among treatments were ≤1 °C). In sunflower and maize, the source (ISR)–sink (grain number) ratio during the grain filling period better explained changes in oleic acid percentage than per plant ISR alone. Changes in fatty acid composition due to radiation treatments were as large as variations produced by changes in temperature in soybean and maize, but not in sunflower. Based on these results, management practices that increase intercepted radiation by the plant during grain filling could contribute to obtain oils with higher oleic acid percentage.

Biodiesel is an alternative fuel made from vegetable oils or animal fats. The fatty acid composition of the feedstock, which varies among and within species, is the main determinant of biodiesel quality. In this work we analyze the variability in biodiesel quality (density, kinematic viscosity, heating value, cetane number and iodine value) obtained from sunflower oil, by means of a validated crop model that predicts the fatty acid composition of one high-oleic, and three traditional (high-linoleic) sunflower hybrids. The model was run with a 10-year average weather data from 56 weather stations in Argentina, and simulation results were compared to the biodiesel standards of Argentina, USA and Europe. We show that biodiesel produced from sunflower oil does not have one fixed quality, but different qualities depending on weather conditions and agricultural practices, and that intraspecific variation in biodiesel quality can be larger than interspecific differences. Our results suggest that (a) sunflower oil from high-oleic hybrids is suitable for biodiesel production (within limits of all analyzed standards), regardless of growing conditions and (b) sunflower oil from traditional hybrids is suitable for biodiesel production under the standards of Argentina and USA, while only certain hybrids grown in warm regions (e.g., Northern Argentina, Southern USA, China, India, Pakistan) are suitable for biodiesel production according to the European standard.

It is not known if the response of the oil fatty acid composition to temperature is similar among sunflower hybrids, especially among traditional hybrids. The objective of this work was to asses the genetic variability of the response of the oil fatty acid composition to temperature during the period 100–300 °C day after flowering among sunflower hybrids. Seven traditional hybrids and a high oleic hybrid were grown in several locations of Argentina. With the same hybrids two experiments were carried out in growth chambers where the plants were exposed to different day–night temperatures during grain filling. From these field and growth chamber experiments wide ranges of variation of temperature and oil fatty acid compositions for each hybrid were obtained. The concentration of oleic acid in sunflower oil showed a sigmoidal response to minimum night temperature from 100 to 300 °C day after flowering, increasing almost lineally within a given range of temperature. Outside this range, the concentration of this fatty acid remained merely constant. The same mathematical expressions characterized the response of oleic acid concentration to temperature in both, traditional and high oleic hybrids. The same expression also described the response of other fatty acids to temperature in all the hybrids. Differences between hybrids were observed for the minimum and maximum concentration of oleic acid and also for the maximum slope and range of the response. Since the sum of oleic + linoleic acids increased with temperature, increasing temperature reduced the concentration of saturated fatty acids and behenic acid. Genetic variability in the response of these fatty acids to temperature was observed. The results presented here show that it is possible to obtain sunflower oils of very different qualities combining the genetic variability in the response of the fatty acid composition to temperature and the climatic diversity under which sunflower is cultivated.

The effect of intercepted photosynthetically active radiation (PAR) on weight per grain and oil concentration and their dynamics was investi- gated in several sunfl ower (Helianthus annuus L.) striped and black hull hybrids grown in contrast- ing environments. The study included the pre- viously investigated hybrids Dekalb G-100 and NKT, and two near isohybrids, which differed in the character of the type of hull. The effect of intercepted PAR lower than those studied in previous works was also investigated. Oil con- centration was affected by intercepted radiation but striped hull hybrids reached the maximum oil concentration at lower levels of intercepted PAR than black hull hybrids. A decrease in inter- cepted radiation decreased fi nal oil concentra- tion mainly due to a lower duration of the phase during which oil concentration linearly increases. Despite the hull type, changes in grain oil con- centration that were originated by changes in intercepted radiation largely depended on kernel oil concentration. No differences were observed in the response of weight per grain to changes in intercepted radiation among black hull and striped hull hybrids. Low sensitivity of oil concentration to changes in intercepted PAR must be considered for modeling grain quality. Striped hull hybrids could perform as black hull hybrids in environments with low intercepted radiation during grain fi lling.

Resumen Objetivo El objetivo de este estudio fue documentar la factibilidad, la seguridad y los resultados a corto plazo de la cirugia laparoscopica de colon durante los primeros anos de implantacion de dicha tecnica en nuestro servicio. Metodo Entre enero de 2002 y diciembre de 2005, se propuso cirugia laparoscopica a los pacientes con indicacion quirurgica por afeccion benigna de colon. A partir de 2003, se incluyo tambien a los pacientes con enfermedad maligna. Se creo una base de datos, actualizada, donde se incluyeron los datos demograficos, la indicacion quirurgica, la tecnica, la tasa de conversion, la morbilidad y la estancia postoperatoria. Todos los pacientes fueron intervenidos por un mismo equipo de 3 cirujanos. Resultados Fueron intervenidos 90 pacientes consecutivos, con media de edad de 59,2 (intervalo, 20-88) anos. De ellos, 53 (59%) eran varones. En total, 32 (35,5%) pacientes presentaban una o mas laparotomias previas por via abierta. La indicacion fue por causa benigna en 60 (66%) casos. La distribucion fue de 79 casos en colon izquierdo y 11 en colon derecho. La tecnica mas frecuente fue la sigmoidectomia (67,7%). La tasa de conversion fue del 12,2%. El tiempo de intervencion, 199 (120-340) min y la estancia postoperatoria, de 7,5 (4-57) dias. La morbilidad fue del 18,8% y la mortalidad, del 1,1%. Conclusiones La cirugia laparoscopica de colon es segura y reproducible. Nuestros resultados a corto plazo son comparables a los resultados historicos publicados. Creemos que la experiencia laparoscopica previa es importante y que un equipo quirurgico estable minimiza el impacto de la curva de aprendizaje.

Wheat production ( Triticum aestivum L.) has increased across the world during last century with the intensification of agriculture. Phosphorus (P) fertilization is a common practice to improve wheat growth in Argentina. We investigate whether indigenous arbuscular mycorrhizal colonization (AMC) of hard red spring wheat is controlled by shoot P content (SPc) or by available soil P in an agricultural soil from the southeastern Argentine Pampas. In the field, AMC was monitored four times during two growing seasons of a conventional wheat crop. Treatments were: without P supply, annual supply of 11 and 22 kg P ha −1 during the last 5 years, and 164 kg P ha −1 applied once 5 years before the experiment. In the glasshouse, AMC was assessed three times in wheat growing in pots filled with the soil from unfertilized plots; treatments were: P (0 and 20 mg P pot −1 ), and nitrogen (N) fertilization (0 and 150 mg N pot −1 ). A range of soil P between 6 and 60 mg P kg −1 was obtained and the AMC ranged from 1% to 67% of root length colonized under both field and glasshouse conditions. P supplied annually increased growth and SPc but decreased AMC. N fertilization did not affect growth or AMC. Variations in SPc did not account for AMC. Variability in AMC was best accounted for local current soil available P content ( r 2 = 0.59). A linear-plateau relationship between soil P and indigenous AMC was established in wheat plants growing under contrasting environmental and experimental (field and glasshouse) conditions. Indigenous AMC was depressed by available soil P in the range 0–27 mg P kg −1 (a decrease of 2.8% mg P −1 kg −1 ). Above 27 mg P kg soil −1 , AMC was stabilized at about 10%. Grain yield increased with fertilization and the highest relative shoot dry matter in field was obtained at 15.5 mg P kg soil −1 . The soil P range that ensures high wheat production without deterring indigenous AMC is discussed.

This study characterized the influence of temperature during grain filling on the saturated fatty acid distribution in triacylglycerol molecules from high stearic sunflower lines with different genetic backgrounds. Two growth chamber experiments were conducted with day/night temperatures of 16/16, 26/16, 26/26 and 32/26 °C.In all genotypes, independently of the genetic background, higher temperatures increased palmitic and oleic acid and reduced linoleic acid concentrations. Increasing night temperature produced an increase in saturated-unsaturated-saturated species, indicating a more symmetrical distribution of saturated fatty acids. The solid fat index was more affected by temperature during grain filling in lines with high linoleic than high oleic background. Higher variations in symmetry among night temperatures were observed in lines with high oleic background, which are more stable in fatty acid composition.The effect of temperature on triacylglycerol composition is not completely explained by its effect on fatty acid composition. Thus night temperature affects oil properties via its effects on fatty acid synthesis and on the distribution of fatty acids in the triacylglycerol molecules. © 2016 Society of Chemical Industry.

Drought is a major limitation to crop yields worldwide. Screening for soybean yield under water deficit is often a bottleneck in breeding programmes. We assessed the validity of a standardized drought tolerance screening method to predict water-limited field performance of soybean in NW Argentina. First, to determine the phenological period when yield of glasshouse-grown plants was more sensitive to water deficit, we applied treatments during 21 days in V7, R3 or R5 stages, being the period from R5 to R6 the most critical for yield. Afterwards, two glasshouse experiments were carried out to quantify the tolerance of either eight or four genotypes, respectively, by applying a controlled water deficit of constant intensity during the critical period. Finally, yield data obtained in field trials in Argentina across several locations and seasons classified according to rainfall were analysed. Drought Susceptibility Index was calculated for each experiment and for field data, and rankings of tolerance were similar in all cases. This standardized method, which can be automated for high-throughput phenotyping, could represent a useful tool in breeding programmes for identifying soybean cultivars with improved performance under drought conditions. Fil: Pardo, E. M.. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina; Argentina Fil: Vellicce, Gabriel Ricardo. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina; Argentina Fil: Aguirrezábal, Luis Adolfo Nazareno. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina Fil: Pereyra Irujo, Gustavo Adrian. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires. Estación Experimental Agropecuaria Balcarce; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina Fil: Rocha, Carla Maria Lourdes. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina; Argentina Fil: García, M.. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina; Argentina Fil: Prieto Angueira, S.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Tucumán-Santiago del Estero. Estación Experimental Agropecuaria Santiago del Estero; Argentina Fil: Welin, Bjorn. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina; Argentina Fil: Sanchez, J.. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina; Argentina Fil: Ledesma, F.. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina; Argentina Fil: Castagnaro, Atilio Pedro. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán. Instituto de Tecnología Agroindustrial del Noroeste Argentino; Argentina; Argentina

Grain quality is a complex character primarily determined by processes at the crop level. This chapter reviews the effects of environment, genotype, and their interactions, on grain oil and protein concentration and composition. The focus is on sunflower as an oilseed model and bread wheat as a cereal model. Sunflower oil composition is analyzed in terms of concentration and composition of fatty acids, tocopherols and phytosterols while, in bread wheat, grain prolamin composition is considered. Process-based crop models accounting for grain yield in both species, and for concentration and composition of oil (sunflower) and protein (wheat) are described. A combination of modeling and experiments allowed analysis of the relationships between quality traits and yield. Finally, we use physiologically-based relationships of yield and oil attributes (sunflower) and yield and protein attributes (wheat) to design management and breeding strategies for grain quality improvement.

Background and Aims: Grapevine bunch compactness is an important trait with impact on fruit quality, mainly affecting the susceptibility to bunch rot. Many and different variables have been reported to have a significant influence on the variation of bunch compactness in particular cultivars, but little is known about the role of such variables in a wider framework. The aim of this work was to identify and weight the features responsible for the natural variation in bunch compactness in a large and diverse grapevine collection. Methods and Results: Different statistical tests were sequentially applied to select the determining variables most influencing bunch compactness. Significant and low correlation was obtained for most of the variables studied for three consecutive seasons, confirming the multifactorial nature of this trait. Multivariate analyses indicated that there are three groups of variables with a significant influence on bunch compactness. Two groups, represented by the total number of berries per bunch and by the length of the first ramification of the bunch, are major factors responsible for the trait variation, whereas berry dimensions have a secondary role. Conclusions: Bunch compactness is defined by the difference between its morphological (apparent) volume and its actual (solid) volume. The results showed that the actual volume is mainly determined by the total number of berries, whereas the morphological volume also depends on its spatial arrangement, determined by the architecture of the rachis. Significance of the Study: This is the first multiyear study of bunch compactness at a multicultivar level, and it has allowed the selection and weighting of the main variables affecting the trait. These variables are suitable targets to study the underlying genetics of the trait.

Publisher Summary Agronomy is the science and technology of producing and using plants for food, fuel, and fiber. Crop physiology studies the structure and function of crops in relation to productivity and quality product for different uses. This chapter discusses physiology and agronomy together of sunflower crop, giving the basis for the crop management and genetic improvement of sunflower from a physiological point of view. It also discusses some differences among the physiology of sunflower and other crops. Applying ecophysiological knowledge could be helpful to optimize sunflower crop management to obtain high yields and high oil quality; to save soil water and nutrients; and to reduce the application of chemical products. It could be expected that sunflower production and crop system sustainability could be improved by a greater adoption of precision agriculture. Information systems could help to take into account the spatial heterogeneity of soil and crop properties as a decision support for process optimization. Adjustments of sowing date, plant population, and row spacing, as well as the selection of hybrid cycle are important agronomical practices to improve the performance of rain-fed sunflower crops when sown in environments with middle and high probabilities of facing drought periods.

Oil quality highly depends on its fatty acid composition. In traditional sunflower (Helianthus annuus L.) hybrids, fatty acid composition is affected by night temperature during grain filling. It is unknown if the increase of oleic acid concentration when night temperature increases saturates at a temperature threshold. Modeling the response of fatty acid composition to temperature could lead to oil quality prediction. The objectives of this work were: (i) to develop precise models to estimate fatty acid composition, and (ii) to use the established models to assess differences in final fatty acid composition among regions, sowing dates, and years. The traditional hybrid Dekasol 3881 was exposed to different day–night temperature regimes during grain filling (28 and 20C, 25 and 23C, and 20 and 28C). To model the response of fatty acid composition to temperature data from two field experiments, eight field crops and five growth chamber experiments were analyzed. Night minimum temperature during the 100 to 300 ddaf (degree-days after flowering) period (base temperature 5 6C) accounted for most of the variability in oleic acid concentration (r 2 5 0.84). The relationship was linear up to 22.6C, the temperature at which the maximum value of oleic acid was reached. The model also estimated other fatty acid contents. The relationships accurately predicted independent data from Dekasol 3881 and other hybrids. Our model explained most of the variation in oleic acid concentration observed in a large region were sunflower is cultivated (27–37 S) and it is feasible for a wide range of environmental conditions.

The effect of pre and post-anthesis shading (20% of incident radiation) on pericarp development, cotyledon cell number and seed growth dynamic of fruits from three positions in the capitulum (peripheral, mid and central) of two sunflower (Helianthus annuus L.) genotypes were studied at two locations. Both shading treatments reduced pericarp weight, fruit volume and total yield per plant. Plants shaded during pre-anthesis maintained the number of filled fruits but reduced their individual weight and cotyledon cell number in the three positions on the capitulum. In contrast, postanthesis shading reduced the number of filled fruits but their individual weight and cotyledon cell number were reduced only in the central fruits.

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.

Tocopherols are natural antioxidants that increase the stability of fat-containing foods and perform important biological activities. Significant variations (389 to 1873 μg g oil-1) in the total tocopherol concentration of sunflower seed oil have been reported. The main objectives of this work were to determine the influence of intercepted photosynthetically active radiation on tocopherol concentration during seed filling and to establish and validate relationships between tocopherol concentration in oil and other quality variables of the seed. Seven sunflower hybrids were grown under good water and nutritional conditions in two similar experiments carried out in two contrasting environments. Treatments were applied to modify the amount of radiation intercepted per plant during seed filling in order to obtain a range in oil yield per plant and its components. Greater per plant intercepted radiation decreased the tocopherol concentration in oil. Tocopherol concentration decreased when oil weight per seed increased. Tocopherol concentration stabilized for oil weight per seed higher than 23 mg oil seed -1. This exponential relationship accounted for 73% of the variability in tocopherol concentration (507 to 1203 μg g oil-1) despite differences in hull type, locations, hybrids, and radiation treatments. The proposed relationship acceptably predicted independent results. Crop management techniques could lead to seeds with greater concentrations of tocopherols. Fil: Nolasco, Susana Maria. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ingeniería Olavarría. Departamento de Ingeniería Química; Argentina Fil: Aguirrezábal, Luis Adolfo Nazareno. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; Argentina Fil: Crapiste, Guillermo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina

In grapevines, stomatal aperture decreases after a mid-morning peak during summer days. Afternoon stomatal closure increases in non-irrigated plants as water limitation progresses, which suggests the involvement of abscisic acid (ABA) in the control of stomatal aperture. The objective of this work was to study the seasonal and diurnal time-courses of CO2 assimilation rate, leaf conductance, leaf water potential (Y), and ABA concentration in xylem sap, leaves, flowers and berries in non-irrigated field-grown Tempranillo grapevines throughout reproductive development. Leaf Y decreased throughout fruit development because water availability decreased towards the end of the reproductive cycle. CO2 assimilation rate, leaf conductance and xylem ABA concentration also decreased during the course of the growing season. Combining all measurements xylem ABA was either not correlated, or only slightly correlated, with leaf water status (Y) and daily leaf conductance, respectively. This lack of relationship indicates that xylem ABA during fruit ripening had functions other than provision of a non-hydraulic signal. On a seasonal basis, xylem ABA concentration measured in non-irrigated grapevines was well related to berry ABA concentration, especially at the end of fruit development (veraison and harvest).

Fatty acid composition is affected by plant genotype and environmental conditions with temperature a major effect. The effect of night temperature during different periods of fruit filling on the fatty acid composition of sunflower oil from hybrids with different potential oleic acid content has never been studied. This information is needed if we are further to improve oil quality. A traditional, a mid oleic and two high oleic hybrids were sown in the field on 3 November 1998. The traditional hybrid was also sown again on 22 November 1998. In each experiment, four treatments were applied; a control and three treatments in which night temperature was increased 6.9 °C at three different consecutive periods of 200 °C day after flowering. A third experiment was carried out in growth chambers using the same genotypes as in the previous experiments plus another high oleic hybrid. Three day–night temperatures (16–26, 22–20 and 26–16 °C) were applied to plants from flowering to physiological maturity. In general, oleic acid percentage was higher with higher night temperature and was not related to daily minimum temperature. The largest variation in oleic acid percentage was observed in the traditional hybrid and the lowest in the high oleic hybrids. Higher oleic acid percentage was associated with an increase in night temperature early during fruit filling. Variation in oleic acid percentage was related to variation in linoleic acid percentage in all experiments.

Unknown to the Spanish Romantics, Novalis was nevertheless translated by modernist writers and, in the years previous to the making of La lampara maravillosa , his work was disseminated by people who were attracted to theosophy and other esoteric beliefs. Heinrich von Ofterdingen was a seminal work in the development of the narrative, poetological subgenre that turned Bildungsroman into an aesthetic «camino de perfeccion». The recurrent critical problem of placing La lampara maravillosa within a particular genre can be explained in relation to this tradition. As Novalis han done in Heinrich von Ofterdingen , Valle advanced in his work a magic poetics that agreed with the German's on every essential point.

Unknown to the Spanish Romantics, Novalis was nevertheless translated by modernist writers and, in the years previous to the making of La lámpara maravillosa, his work was disseminated by people who were attracted to theosophy and other esoteric beliefs. Heinrich von Ofterdingen was a seminal work in the development of the narrative, poetological subgenre that turned Bildungsroman into an aesthetic «camino de perfección». The recurrent critical problem of placing La lámpara maravillosa within a particular genre can be explained in relation to this tradition. As Novalis han done in Heinrich von Ofterdingen, Valle advanced in his work a magic poetics that agreed with the German's on every essential point. 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.

The effect of intercepted solar radiation during fruit filling on seed weight and oil content from seeds of three sectors of the head in two sunflower (Helianthus annuus L.) hybrids of low and high potential oil percentage was investigated. Seed weight in each sector depended on both the level of radiation intercepted (modified by shading and thinning plants) and the genotype grown. A higher level of intercepted solar radiation increased seed weight in each sector. Central seeds of shaded plants showed the lowest weight. The seed and kernel oil content hierarchy among the three sectors was modified only in the hybrid with high potential oil content. For each head sector, variations in seed oil content associated with changes in the level of intercepted radiation could be accounted for by changes in the kernel oil content, not in the kernel/seed ratio. Significant relationships were found between seed oil and kernel oil contents when analyses between treatments (R>0.86) and sectors (R>0.92) were carried out. These relationships together with the growing conditions of plants during seed filling, the genotype, and the seed position on the head are essential factors that should be taken into account when selecting seeds in sunflower breeding programs since they affect the commercial/industrial quality of seeds.

La compacidad del racimo de vid (Vitis vinifera L.) y los factores individuales que definen este carácter repercuten en la calidad de la uva, siendo un atributo que determina en gran manera el estado sanitario del fruto, y la homogeneidad de la maduración del racimo. A pesar de su importancia agronómica y comercial, se trata de un carácter escasamente estudiado desde el punto de vista genético, probablemente debido a su elevada complejidad y a la ausencia de un criterio armonizado para su medida cuantitativa y objetiva, lo que a su vez dificulta ciertos estudios comparativos intervarietales. El principal objetivo de este estudio ha sido la identificación y evaluación de aquellos elementos estructurales de la morfología del racimo involucrados en la determinación de su compacidad. Para ello se ha llevado a cabo la caracterización, a través de 23 descriptores cuantitativos, de un gran número de racimos pertenecientes a variedades de vid de distinta aptitud comercial (uva de mesa y uva de vinificación). El estudio se ha desarrollado durante tres campañas consecutivas: 2011 (1040 racimos), 2012 (1145 racimos) y 2013 (977 racimos), que se han estudiado separadamente. El análisis univariante de los datos de fenotipado reveló la naturaleza multifactorial de este carácter, resultado de la combinación de numerosos atributos del racimo. La aplicación de diversos análisis multivariantes indicó que el número de bayas del racimo, la longitud de las primeras ramas del raquis y, en menor medida, el tamaño final de la baya son los factores más determinantes en la compacidad del racimo de vid.

Fire increases forage availability and forage quality in grasslands dominated by Paspalum quadrifarium in the Flooding Pampa, Argentina. We evaluated the effect of burning on soil water content and the above ground productivity. The study area was located near the San Ignacio railroad station at the Ayacucho county, Province of Buenos Aires. The experiment was a completely randomized block design with two blocks and two treatments: burned (B) and unburned (NB). Volumetric soil moisture content and water table level was measured during two growing seasons. Water use was estimated for the spring-fall period using volumetric water content, water table depth and daily precipitation. Volumetric water content was consistently lower and water use was higher for the burned treatments. Lower volumetric water content and higher water use for the burned treatments were associated fire enhanced growth of the dominant species.

SUMMARY This work was aimed to study, under different levels of radiation intercepted by the plants during the seed filling stage, the relationship between yield and vascularization in three concentric positions of the capitulum. At the end of flowering, we applied shading (to reduce intercepted radiation) and thinning (to increase it) to three culture plots: a shaded plot, a thinned plot and a shaded and thinned plot. One additional untreated plot was used as control. We harvested heads at flowering and at physiological maturity. We delimited on them three positions: outer, middle and inner. Portions of each position were extracted from physiological maturity heads and their yield components were determined. The remaining heads were fixed in F.A.A., soaked in paraffin, and transversely cut at seed insertion to measure vascularization variables (phloem and sieve tubes area, number of tranverse and longitudinal bundles and sieve pores diameter). The head area unit was used as a base in all measurements. Shading reduced dry weight in the three positions. The middle position showed the highest yield and the inner showed the lowest in the four plots. The yield of the former was high because its lower individual seed weight (decreasing from periphery to center in all plots) was compensated by a higher number of filled seeds. However, average sieve pores radius was similar among positions, and phloem and sieve tubes areas were similar among positions and treatments, which could not account for the differences in yield per head area unit between positions. This enables us to conclude that this variation would not be produced by vascularization lack.