Onion Cultivars Released by La Consulta Experiment Station, INTA, Argentina

The onion crop is of great importance in Argentina and, with garlic (Allium sativum L.), is the main fresh vegetable exported. The principal market for Argentine onions is Brazil, with significant exports to Europe and the United States. About 450,000 t of onions are produced yearly on 22,000 ha, for the freshmarket and dehydration industries (Galmarini, 1998). Onion seed production is also important in Argentina; ≈50,000 kg of seed is produced annually by domestic and international seed companies.EEA La ConsultaFil: Galmarini, Claudio Romulo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina

Efecto de factores ambientales en la actividad de la abeja y en el rendimiento de semilla de cebolla (Allium cepa L.)

Los polinizadores son necesarios para producir semillas de cebolla. Esta especie es uno de los principales cultivos hortícolas. Dos tipos de variedades de cebolla se cultivan principalmente en todo el mundo: híbridos y cultivares de polinización abierta (PA). Aunque los híbridos ofrecen ventajas a los cultivadores de bulbos, los rendimientos de semillas de los híbridos son más bajos que los cultivares PA y eso es un problema importante. Se determinó la influencia de los factores ambientales (temperatura, radiación, precipitación, humedad relativa (HR) y velocidad del viento), así como la atracción de abejas y la producción de semillas en tres localidades, de principal zona productora de semillas de cebolla en Argentina. Se utilizaron nueve líneas androestériles (LAE) y una PA. Los resultados obtenidos mostraron una marcada variabilidad en la atracción de abejas y la producción de semillas entre la variedad PA y las LAE y dentro de las LAE. Además, los factores ambientales, como la temperatura mínima o HR, fueron determinantes para modificar el comportamiento de alimentación de las abejas, donde valores inferiores a 9°C y 22%, respectivamente, hicieron que las abejas detuvieran su actividad.Pollinators are required to produce onion seeds. This specie is one of the main vegetable crops. Two types of onion varieties are mainly grown worldwide: hybrids and open pollination (OP) cultivars. Although hybrids offer advantages to bulb growers, seed yields of hybrids are lower than OP cultivars and that is a significant problem. The influence of environmental factors (temperature, radiation, rainfall, relative humidity (RH) and wind speed) was determined,as well as bee attraction and seed production in three locations of the main onion seed production area in Argentina. Nine male sterile lines (MSL) and one OP were used. The results obtained showed a marked variability in the attraction of bees and seed production between the OP and MSL and within MLS. In addition, environmental factors such as minimun temperature or RH were determinant to modify bee foraging behavior, where values lower than 9°C and 22%, respectively, caused that bees stop their activity.Fil: Caselles, Cristian. Bayer Cropscience Sociedad Anonima; ArgentinaFil: Soto Vargas, Verónica Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Biología Agrícola de Mendoza. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Instituto de Biología Agrícola de Mendoza; ArgentinaFil: Galmarini, Claudio Romulo. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción Agropecuaria. Cátedra de Horticultura y Floricultura; Argentina. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Inheritance of Vernalization Requirement in Carrot

Carrot (Daucus carota L.) is a cool-season vegetable normally classified as a biennial or winter annual species, requiring vernalization to induce flowering. Nevertheless, some cultivars adapted to warmer climates require less vernalization and can be classified as early flowering or annual. The genetic control of this phenotypic difference has not been previously studied in carrot. The authors evaluated F1, F2, and BC1 progenies of an intercross between the early-flowering carrot (‘Criolla INTA’) and a late-flowering biennial carrot. F1 progenies were completely annual. Observed segregation ratios in the F2 and BC1 families were not significantly different from expected segregation ratios under the hypothesis of a single dominant gene conditioning the early-flowering habit. The authors conclude that annual habit is dominant over biennial and is a monogenic character.EEA La ConsultaFil: Alessandro, María Soledad. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina.Fil: Galmarini, Claudio Romulo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina

Effect of processing and cooking conditions on onion (Allium cepa L.) induced antiplatelet activity and thiosulfinate content

Allium vegetables serve as sources of antiplatelet agents that may contribute to the prevention of cardiovascular disease. However, onion and garlic, the major Allium species, are usually cooked before consumption. Here, we examined the effect of cooking on onion in vitro antiplatelet activity (IVAA). Two different cooking systems (convection oven and microwaves) and several time−temperature variables were tested on whole bulbs, quarters of bulbs, and completely crushed bulbs, monitoring the degradation of sulfur antiplatelet compounds (e.g., thiosulfinates) by analysis of pyruvate levels. Although heating was, in general, detrimental for onion IVAA, the extent of this effect varied greatly, from unaffected antiplatelet activity (AA) (i.e., similar to raw onion) to a complete lost of activity, depending upon the manner in which onions were prepared prior to heating, the cooking method, and the intensity of the heat treatment. “Whole”, “quarters”, and “crushed” onions lost their IVAA after 30, 20, and 10 min of oven heating, respectively. The longer retainment of AA in intact bulbs was attributed to a later alliinase inactivation. Proaggregatory effects  observed in samples subjected to the most intense oven and microwave heat treatments suggest that extensively cooked onions may stimulate rather than inhibit platelet aggregation. The efficacy of Allium species as antiplatelet agents, as affected by preparation and cooking conditions, is discussed.Fil: Cavagnaro, Pablo Federico. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; Argentina. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; ArgentinaFil: Galmarini, Claudio Romulo. Universidad Nacional de Cuyo; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Mendoza-San Juan. Estación Experimental Agropecuaria La Consulta; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentin

Exogenous cytokinin promotes Epipremnum aureum L. growth through enhanced dry weight assimilation rather than through changes in partitioning

Aims: Benzylaminopurine (BAP) sprays have been shown to increase leaf size and leaf appearance rate, as well as biomass accumulation in pot-grown Epipremnum aureum L. BAP-mediated enhanced growth could either be the consequence of a higher investment of dry weight in leaf area development thus leading to a positive dry weight accumulation feedback, to a promoting effect on dry weight assimilation per unit leaf area. Study Design: A randomized complete block factorial design with three blocks was used. Place and Duration of Study: Two experiments were carried out in a greenhouse at the Faculty of Agronomy, University of Buenos Aires, Argentina (34°28’S) from the 8th September 2007 and 5th September 2008, respectively, to the 12th March 2008 and 11th March 2009 respectively. Methodology: We analyzed the effect of exogenous BAP supplied in different number of applications and at different concentrations under three light intensities, on dry weight accumulation and partitioning in E. aureum grown in pots, in two greenhouse experiments. Results: A single 5mg L-1 BAP application was enough to increase the dry weight accumulation rate in comparison to untreated controls, irrespective of the light intensity. A strong direct relationship between the relative growth rate (RGR) and the net assimilation rate (NAR) were found, while an inverse relationship was observed between RGR and the leaf area ratio (LAR). Even though BAP increased dry weight partitioning to the aerial part, as revealed by shoot vs. root allometric analysis, this did not result in a LAR increase, but rather in higher stem dry weight accumulation, in association with a decrease in the leaf area partitioning coefficient (LAP). NAR promotion by BAP was associated with an increased N content per unit leaf area, rather than with changes in chlorophyll content. Conclusion: Our results on the ornamental shade plant E. aureum also provide information which may help to increase productivity to this crop from a grower perspective.EEA La ConsultaFil: Di Benedetto, Adalberto. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Galmarini, Claudio Romulo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Tognetti, Jorge. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires; Argentin

Estructura del nectario floral, presentación del néctar y análisis morfo-anatómico de anteras de líneas androfértiles y androestériles en cebolla (Allium cepa, Amaryllidaceae)

Background and aims: The onion (Allium cepa var. cepa) is an allogamous species in which male-sterile lines have been developed. However, the structure of the flower and floral nectaries have only been briefly described. The objective of this study is to update the floral anatomy data, comparing the gynoecium and androecium of male-fertile and male-sterile lines, and to analyze the three-dimensional structure of the floral nectary. M&M: Conventional optical and scanning electron microscopy techniques were used. Results: Fertile and sterile male flowers have the same structural organization. The septal or gynopleural nectary is organized in three zones: 1) production area formed by the glandular tissue arranged radially in the septa of the ovary, 2) discharge zone: a small channel at the apex connects the nectariferous tissue with the pocket formed between the ovary wall and the overlying ridge, and 3) presentation and harvest zone, where the excreted nectar accumulates, formed between the widened base of the inner staminal filaments opposite the ovary. Conclusions: The only anatomical differences in the flowers sterile male lines are the lack of pollen production and the absence of dehiscence, despite having a normal stomium and anther wall. The floral nectaries of onion are a clear example of secondary presentation of nectar.Introducción y objetivos: La cebolla (Allium cepa var. cepa) es una especie alógama, donde se han desarrollado líneas androestériles. La estructura floral y la de sus nectarios florales ha sido descrita de manera somera e incompleta. El objetivo del presente trabajo es actualizar los datos de la anatomía floral comparando líneas fértiles y androestériles y analizar la estructura tridimensional del nectario floral.  M&M: Se utilizaron técnicas convencionales de microscopía óptica y electrónica de barrido.  Resultados: Las flores fértiles y androestériles presentan la misma organización estructural. El nectario septal o ginopleural se organiza en tres zonas: 1) área productora formada por el tejido glandular dispuesto radialmente en los septos del ovario, 2) zona de descarga: un pequeño canal en el ápice conecta el tejido nectarífero con el bolsillo formado entre la pared del ovario y la cresta que los cubre, y 3) zona de presentación y cosecha, donde el néctar excretado se acumula, formada entre la base ensanchada de los filamentos estaminales internos y la base del ovario.  Conclusiones: Las únicas diferencias anatómicas en las flores de las líneas androestériles y las fértiles radican en la falta de producción de granos de polen y la ausencia de dehiscencia, pese a presentar estomio y pared de anteras normales. Los nectarios florales de la cebolla son un claro ejemplo de presentación secundaria del néctar

New insight into how thigmomorphogenesis affects Epipremnum aureum plant development

Climbing Epipremnum aureum plants develop larger leaves than unsupported, hanging plants. This effect may be regarded, in part, as a thigmomorphogenic response, but gravimorphogenetic effect may also be involved, since polar auxin transport is known to be negatively affected in plants with horizontal or hanging stems, which may result in an altered hormone balance at the whole plant level. The present work was aimed at studying how exogenous auxins and cytokinins may influence growth of E. aureum rooted cuttings under different training systems. Rooted cuttings of E. aureum were cultivated either climbing on an upright wooden board or creeping on the glasshouse bench or hanging from a basket. All leaves of each plant were sprayed to run-off at sunset with four indole-3-acetic acid (IAA) doses 7 days after transplanting and one week later, with four benzylaminopurine (BAP) concentrations, rendering 16 hormone combination treatments. The application of IAA or BAP at 50 mg L-1 to creeping and hanging plants significantly promoted growth but, in climbing plants, a negative effect was generally observed. Changes in net assimilation and photosynthetic rates, together with modified allometric coefficients, accounted for these responses. The higher growth promotion by exogenous growth regulators observed in creeping or hanging plants compared to climbing plants, may be interpreted mostly as a gravimorphogenetic response.Plantas trepadeiras (Epipremnum aureum) conduzidas suspensas, desenvolvem folhas maiores em comparação com plantas conduzidas sem suporte (rasteiras). Esse efeito pode ser visto, em parte, como uma resposta thigmomorfogênica; mas o efeito gravimorfogênico também pode estar envolvido, uma vez que o transporte polar de auxinas é afetado negativamente em plantas com hastes horizontais ou pendentes, o que pode resultar em um balanço hormonal alterado, a nível da planta como um todo. O presente trabalho teve como objetivo estudar como as auxinas e citocininas exógenas podem influenciar o crescimento de estacas enraizadas de E. aureum sob diferentes sistemas de condução. Estacas enraizadas de E. aureum foram cultivadas como trepadeiras em uma tábua de madeira vertical ou rasteiras sobre bancada em casa de vegetação ou suspensas em uma cesta. Todas as folhas de cada planta foram pulverizadas até escoamento à tarde, com quatro doses de ácido indol-3-acético (AIA), 7 dias após o transplante e, após uma semana, com quatro concentrações de benzilaminopurina (BAP), resultando em 16 tratamentos combinados com hormônios. A aplicação de IAA ou BAP a 50 mg L-1 em plantas rasteiras e suspensas, promoveu crescimento significativo mas, em plantas trepadeiras, observou-se, em geral, efeito negativo. Mudanças na assimilação líquida e taxas fotossintéticas, juntamente com coeficientes alométricos modificados, foram responsáveis por essas respostas. A maior promoção do crescimento por reguladores de crescimento exógenos, observada em plantas rasteiras ou suspensas em comparação com plantas trepadeiras, pode ser interpretada principalmente como uma resposta gravimorfogênicaEEA La ConsultaFil: Di Benedetto, Adalberto. Universidad de Buenos Aires. Facultad de Agronomía; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Galmarini, Claudio Romulo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Tognetti, Jorge. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires; Argentin

Differential growth response of green and variegated Ficus benjamina to exogenous cytokinin and shade

Benjamin fig (Ficus benjamina) is an important foliage and landscape crop species comprising green and variegated genotypes. The latter develop leaves with yellow and white leaf areas which may impose lower photosynthetic activity, thus resulting in slower growth than green genotypes. In many species, the exogenous supply of cytokinin to pot-grown plants promotes growth, mainly due to enhanced carbon fixation. In this work, we analyze the effect of spraying the cytokinin 6-benzylaminopurine (BAP) on growth and development of green and variegated Ficus benjamina genotypes. Two experiments were carried out in a greenhouse, in which either different number of BAP applications (Experiment 1) or different BAP concentrations (Experiment 2) were tested. In Experiment 2, plants were grown under three different light intensities. BAP sprays promoted rate of leaf appearance, leaf expansion and whole-plant growth, and the effect was stronger in variegated than in green plants. The relative growth rate promotion by BAP was associated with increased net assimilation rate rather than with variation in the leaf area ratio. On the other hand, shading had a more negative impact on growth and development of variegated plants than in green ones. Variegated plants, unlike green ones, developed leaves with high specific leaf area under the lowest light intensity. This led to high leaf area ratio values, which helped to maintain relative growth rates close to those of plants under moderate shading.O Ficus (Ficus benjamina) é uma importante espécie de folhagem usada no paisagismo que compreende genótipos verdes e variegados. Estes últimos desenvolvem folhas com áreas foliares amarelas e brancas que podem impor menor atividade fotossintética, resultando em crescimento mais lento que os genótipos verdes. Em muitas espécies, o suprimento exógeno de citocinina em plantas cultivadas em vaso promove o crescimento, principalmente devido à maior fixação de carbono. Neste trabalho, analisamos o efeito da pulverização da citocinina 6-benzilaminopurina (BAP) no crescimento e desenvolvimento de genótipos verdes e variegados de Ficus benjamina. Foram realizadas dois experimentos em casa de vegetação, nos quais foram testados diferentes números de aplicações de BAP (Experimento 1) ou diferentes concentrações de BAP (Experimento 2). No experimento 2, as plantas foram cultivadas sob três intensidades de luz diferentes. A pulverização com BAP promoveram taxa de aparência foliar, expansão foliar e crescimento de plantas inteiras, e o efeito foi mais forte em variegadas do que em plantas verdes. A promoção da taxa de crescimento relativo pelo BAP foi associada ao aumento da taxa líquida de assimilação, e não à variação na proporção da área foliar. Por outro lado, o sombreamento teve impacto mais negativo no crescimento e desenvolvimento de plantas variegadas do que nas verdes. Plantas variegadas, diferentemente das verdes, desenvolveram folhas com alta área foliar específica sob a menor intensidade de luz. Isso levou a altos valores da razão de área foliar, o que ajudou a manter taxas de crescimento relativas próximas às das plantas sob sombreamento moderado.EEA La ConsultaFil: Di Benedetto, Adalberto. Universidad de Buenos Aires. Facultad de Agronomía; ArgentinaFil: Di Benedetto, Adalberto. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Galmarini, Claudio Romulo. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Galmarini, Claudio Romulo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria La Consulta; ArgentinaFil: Galmarini, Claudio Romulo. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; ArgentinaFil: Tognetti, Jorge. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Tognetti, Jorge. Comisión de Investigaciones Científicas de la Provincia de Buenos Aires; Argentin

Changes in leaf size and in the rate of leaf production contribute to cytokinin-mediated growth promotion in Epipremnum aureum L. cuttings

The growth of ornamental foliage plants is often limited by pot size, which exerts a restriction on root growth and, therefore, on the production of root-synthesised cytokinins which play key regulatory roles in the development and growth of the shoot. We studied the effect of exogenous 6-benzylaminopurine (BAP) on plant growth and on the development of leaf area in Epipremnum aureum L. plants grown in pots. The hypothesis was that increasing the concentration of shoot cytokinins by foliar spraying of BAP would promote plant growth by overcoming the effects of root restriction on whole plant development. Three glasshouse experiments were conducted using (i) different concentrations of BAP, (ii) different numbers of spray applications, and (iii) different light environments. The results showed that a single spray application of BAP at 5 mg l–1 significantly (P ≤ 0.05) increased leaf area (by 20 – 40%) and biomass [fresh weight (FW)] accumulation (by 30 – 35%), while higher BAP concentrations, or repeated spray applications had less effect. The maximum effect of BAP was observed under intermediate levels of irradiance. The increased development of leaf area in BAP-sprayed plants resulted from increases in both individual average leaf areas (by 100 – 150% cf. the controls) and the rate of leaf initiation (by 30 – 120% cf. the controls). The latter could be attributed to a shortening of the phyllochron, since no branching was observed under any BAP spray treatment. Alternative physiological explanations, as well as possible commercial applications of these BAP-elicited responses are discussed.Fil: Di Benedetto, A.. Universidad de Buenos Aires. Facultad de Agronomia; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; ArgentinaFil: Galmarini, Claudio Romulo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Cuyo Mendoza-san Juan. Estación Experimental Agropecuaria la Consulta; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mendoza; ArgentinaFil: Tognetti, J.. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agrarias; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin

Breeding vegetables of regional interest

La horticultura es una actividad central en la agricultura cuyana. Es un sector que emplea mucha mano de obra permanente y temporaria. En Mendoza se destinan alrededor de 40.000 hectáreas a la producción de hortalizas, las que representan cerca del 9 % de la superficie nacional. Los principales cultivos son ajo (12.000 ha), papa (6.300 ha), tomate para industria (4.000 ha), cebolla (3.500 ha), zanahoria (3.500 ha), zapallo (3.000 ha), lechuga (1.200 ha) maíz dulce (1.200 ha), melón (600 ha), poroto para chaucha (500 ha). Las superficies cultivadas con cada especie varían de año en año. La provincia lidera la producción de las llamadas hortalizas pesadas (ajo, zapallo, papa, cebolla, zanahoria), de tomate para industria, de hortalizas deshidratadas y es una importante zona productora de semillas hortícolas. Existe demanda de cultivares hortícolas de buen comportamiento agronómico y de excelentes características culinarias y medicinales. Desde el año 2002 el Instituto de Horticultura, que por más de 30 años ha llevado adelante planes de investigación relacionados al mejoramiento genético de hortalizas, en especial de tomate, zapallo y poroto, trabaja en forma conjunta con la EEA La Consulta del INTA reconocida por sus trabajos en el ámbito hortícola, en especial el área de mejoramiento genético y producción de semillas hortícolas. Esta integración institucional ha permitido homologar conocimientos, sinergizar los grupos de trabajo, formar recursos humanos y potenciar las actividades de docencia la capacitación y la transferencia. En el marco de la presente convocatoria de los proyectos de la Secretaría de Investigación, Internacionales y Posgrado de la Universidad se plantea la continuidad de las actividades efectuadas en proyectos anteriores. En esta etapa del proyecto se pondrá mayor énfasis en las siguientes especies: zapallo, poroto para chaucha, cebolla y zanahoria. Los objetivos generales vigentes son: Caracterizar germoplasma para su utilización en programas de mejoramiento genético; Producir nuevos cultivares que satisfagan la demanda regional y nacional; Producir semilla básica y certificada para su posterior difusión a los productores; Mejorar la eficiencia de producción de semilla de cebolla y Formar recursos humanos capacitados para el manejo y la utilización de germoplasma hortícola.The production of vegetable crops is an important economic activity in the Cuyo region. It is a labor intensity activity. There is a demand for new vegetable cultivars with good agronomic, culinary and health-benefits characteristics. In recent years with previous projects a lot of local landraces were collected. The purpose of the present project is to use the collected germplasm in breeding programs. On the other hand this project involves the collaboration of two well-known institutions dedicated to Vegetable Research. Those are the Institute of Horticulture that belongs to the University of Cuyo and the Experiment Research Station La Consulta, which belongs to INTA. The interaction between these institutions allows to: develop more competitive research projects and a better use of human and material resources. The main goals of the projects are: To use local vegetable germplasm, in particular of the genus Cucurbita, Phaseolus, Allium, and Daucus for breeding purposes. Obtain new cultivars that satisfy regional and national demand. Produce basic and certified vegetable seed for the growers. Increase the efficiency of onion seed production. Contribute with the formation of human resources able to carry on breeding programs and manage genetic resources