Authors: Battaglia, Marina Esther; Rípodas, Carolina; Clua, Joaquin; Baudin, Mael; Aguilar, Orlando Mario; Niebel, Andreas; Zanetti, María Eugenia; Blanco, Flavio Antonio
Publication Date: 2014.
Language: English.
Abstract:
A C subunit of the heterotrimeric nuclear factor Y (NF-YC1) was shown to play a key role in nodule organogenesis and bacterialinfection during the nitrogenfixing symbiosis established between common bean (Phaseolus vulgaris) andRhizobium etli.Toidentify other proteins involved in this process, we used the yeast (Saccharomyces cerevisiae) two-hybrid system to screen for NF-YC1-interacting proteins. One of the positive clones encodes a member of the Phytochrome A Signal Transduction1 subfamily ofGRAS (for Gibberellic Acid-Insensitive (GAI), Repressor of GAI, and Scarecrow) transcription factors. The protein, namedScarecrow-like13 Involved in Nodulation (SIN1), localizes both to the nucleus and the cytoplasm, but in transgenicNicotianabenthamianacells, bimolecularfluorescence complementation suggested that the interaction with NF-YC1 takes placepredominantly in the nucleus. SIN1 is expressed in aerial and root tissues, with higher levels in roots and nodules.Posttranscriptional gene silencing ofSIN1using RNA interference (RNAi) showed that the product of this gene is involvedin lateral root elongation. However, root cell organization, density of lateral roots, and the length of root hairs were not affectedbySIN1RNAi. In addition, the expression of the RNAi ofSIN1led to a marked reduction in the number and size of nodulesformed upon inoculation withR. etliand affected the progression of infection threads toward the nodule primordia. ExpressionofNF-YA1and the G2/M transition cell cycle genesCYCLIN BandCell Division Cycle2was reduced inSIN1RNAi roots. Thesedata suggest that SIN1 plays a role in lateral root elongation and the establishment of root symbiosis in common bean.
Author affiliation: Battaglia, Marina Esther. 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; Argentina
Author affiliation: Rípodas, Carolina. Centre de Recherche de Nantes. Institut National de la Recherche Agronomique; Francia. 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; Argentina
Author affiliation: Clua, Joaquin. 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; Argentina
Author affiliation: Baudin, Mael. Centre National de la Recherche Scientifique; Francia. Centre de Recherche de Nantes. Institut National de la Recherche Agronomique; Francia
Author affiliation: Aguilar, Orlando Mario. 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; Argentina
Author affiliation: Niebel, Andreas. Centre National de la Recherche Scientifique; Francia. Centre de Recherche de Nantes. Institut National de la Recherche Agronomique; Francia
Author affiliation: Zanetti, María Eugenia. 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; Argentina
Author affiliation: Blanco, Flavio Antonio. 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; Argentina
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Publication Date: 2018.
Language: Spanish.
Abstract:
El género Senna comprende alrededor de 360 especies presentándose el 80% en el continente americano. Varias son conocidas por las propiedades antimicrobianas y farmacológicas. Los antecedentes de actividad antifúngica en Argentina fueron reportados en un estudio de extractos metanólicos de hojas de S. spectabilis frente a Fusarium graminearum. El objetivo de este trabajo fue analizar la actividad antifúngica de 12 extractos metanólicos de distintos órganos de 10 especies del género Senna, recolectadas en el norte de Argentina frente a Fusarium verticillioides, responsable de la podredumbre de la espiga en maíz. Primeramente, todos los extractos fueron evaluados con un ensayo colorimétrico de susceptibilidad. Aquellos que mostraron actividad inhibitoria, luego fueron evaluados mediante bioautografía de contacto, tinción con azul de Evans y azul de anilina, test de crecimiento radial del micelio y por su capacidad para inhibir la producción de fumonisinas. El extracto de frutos de S. spectabilis mostró actividad antifúngica con una Concentración Mínima Inhibitoria de 99,9 μg ml-1. Asimismo, se observaron halos de inhibición significativos en la bioautografía de contacto, mientras que en la tinción con azul de Evans y azul de anilina se visualizaron algunas alteraciones en las hifas. En el test de crecimiento radial del micelio, se observó una reducción significativa, y en lo que respecta a la producción de fumonisinas, los extractos provenientes de frutos mostraron una inhibición en su producción de 48,3% mientras que los extractos de flores el porcentaje fue mayor (86,3%). Finalmente, se pudo determinar que S. spectabilis presenta actividad antifúngica frente F. verticillioides, confiriéndole un nuevo registro de bioactividad a esta especie vegetal.
The genus Senna comprises about 360 species being 80% from the American continent. Several of them are known by their antimicrobial and pharmacological properties. In Argentina antecedents of antifungal activities were reported in studies of methanolic extracts from leaves of S. spectabilis against Fusarium graminearum. The aim of this work was to analyze the antifungal activity of 12 methanolic extracts of different organs of 10 species of the genus Senna collected from northern Argentina against Fusarium verticillioides, causal agent of maize ear rot. At first all the extracts were evaluated to know their antifungal capacity with a colorimetric test. Those which showed inhibitory activity were analyzed by contact bioautography, Evans blue and Aniline blue staining, mycelial radial growth test and also their ability to inhibit fumonisins production. Fruit extract of S. spectabilis showed antifungal activity at a Minimun Inhibitory Concentration of 99.9 μg ml-1. Likewise, in the contact bioautography an inhibition zone was evident, while in Evans blue and aniline blue staining, some alterations in the mycelial hyphae were visualized. In the mycelial radial growth test, a significant reduction was observed, and in the fumonisins production the extracts from fruits showed inhibition of 48.3% while in flowers the percentage was higher (86.3%). Finally, it was determined that S. spectabilis has antifungal activity against F. verticillioides, giving a new record of bioactivity to this plant species.
Instituto de Patobiología
Author affiliation: Di Ciaccio, Lucía Soledad. INTA. Instituto de Patobiología; Argentina
Author affiliation: Fortunato, Renee Hersilia. INTA. Instituto de Recursos Biológicos; Argentina. Universidad de Morón. Facultad de Agronomía y Ciencias Agroalimentarias; Argentina
Author affiliation: Salvat, Adriana Elisabeth. INTA. Instituto de Patobiología; Argentina
Repository: INTA Digital (INTA). Instituto Nacional de Tecnología Agropecuaria
Publication Date: 2019.
Language: Spanish.
Abstract:
La Alfalfa (medicago sativa) es una leguminosa perenne, de crecimiento primavera - verano - otoño que se utiliza como recurso principal en las pasturas de rotación de la Región Pampeana
Estación Experimental Agropecuaria Anguil
Author affiliation: Fontana, Laura María Celia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Anguil; Argentina
Author affiliation: Cabo, Sergio. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Anguil. Agencia de Extensión Rural Anguil; Argentina
Keywords: Medicago Sativa; Forrajes; Leguminosas; Forage; Legumes; Alfalfa.
Repository: INTA Digital (INTA). Instituto Nacional de Tecnología Agropecuaria
Authors: Rípodas, Carolina; Castaingts, Mélisse; Clua, Joaquin; Blanco, Flavio Antonio; Zanetti, María Eugenia
Publication Date: 2015.
Language: English.
Abstract:
In the past decade, plant nuclear factor Y (NF-Y) genes have gained major interest due to their roles in many biological processes in plant development or adaptation to environmental conditions, particularly in the root nodule symbiosis established between legume plants and nitrogen fixing bacteria. NF-Ys are heterotrimeric transcriptional complexes composed of three subunits, NF-YA, NF-YB, and NF-YC, which bind with high affinity and specificity to the CCAAT box, a cis element present in many eukaryotic promoters. In plants, NF-Y subunits consist of gene families with about 10 members each. In this study, we have identified and characterized the NF-Y gene families of common bean (Phaseolus vulgaris), a grain legume of worldwide economical importance and the main source of dietary protein of developing countries. Expression analysis showed that some members of each family are up-regulated at early or late stages of the nitrogen fixing symbiotic interaction with its partner Rhizobium etli. We also showed that some genes are differentially accumulated in response to inoculation with high or less efficient R. etli strains, constituting excellent candidates to participate in the strain-specific response during symbiosis. Genes of the NF-YA family exhibit a highly structured intron-exon organization. Moreover, this family is characterized by the presence of upstream ORFs when introns in the 5′ UTR are retained and miRNA target sites in their 3′ UTR, suggesting that these genes might be subjected to a complex post-transcriptional regulation. Multiple protein alignments indicated the presence of highly conserved domains in each of the NF-Y families, presumably involved in subunit interactions and DNA binding. The analysis presented here constitutes a starting point to understand the regulation and biological function of individual members of the NF-Y families in different developmental processes in this grain legume.
Author affiliation: Rípodas, Carolina. 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; Argentina
Author affiliation: Castaingts, Mélisse. 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; Argentina
Author affiliation: Clua, Joaquin. 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; Argentina
Author affiliation: Blanco, Flavio Antonio. 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; Argentina
Author affiliation: Zanetti, María Eugenia. 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; Argentina
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Authors: Larese, Monica Graciela; Namias, Rafael; Craviotto, Roque Mario; Arango, Miriam R.; Gallo, Carina; Granitto, Pablo Miguel
Publication Date: 2013.
Language: English.
Abstract:
In this paper, a procedure for segmenting and classifying scanned legume leaves based only on the analysis of their veins is proposed (leaf shape, size, texture and color are discarded). Three legume species are studied, namely soybean, red and white beans. The leaf images are acquired using a standard scanner. The segmentation is performed using the unconstrained hit-or-miss transform and adaptive thresholding. Several morphological features are computed on the segmented venation, and classified using four alternative classifiers, namely support vector machines (linear and Gaussian kernels), penalized discriminant analysis and random forests. The performance is compared to the one obtained with cleared leaves images, which require a more expensive, time consuming and delicate procedure of acquisition. The results are encouraging, showing that the proposed approach is an effective and more economic alternative solution which outperforms the manual expert´s recognition.
Author affiliation: Larese, Monica Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y Sistemas; Argentina
Author affiliation: Namias, Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y Sistemas; Argentina
Author affiliation: Craviotto, Roque Mario. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Oliveros; Argentina
Author affiliation: Arango, Miriam R.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Oliveros; Argentina
Author affiliation: Gallo, Carina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Oliveros; Argentina
Author affiliation: Granitto, Pablo Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y Sistemas; Argentina
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Authors: Larese, Monica Graciela; Namias, Rafael; Craviotto, Roque Mario; Arango, Miriam Raquel; Gallo, Carina Del Valle; Granitto, Pablo Miguel
Publication Date: 2014.
Language: English.
Abstract:
In this paper, a procedure for segmenting and classifying scanned legume leaves based only on the analysis of their veins is proposed (leaf shape, size, texture and color are discarded). Three legume species are studied, namely soybean, red and white beans. The leaf images are acquired using a standard scanner. The segmentation is performed using the unconstrained hit-or-miss transform and adaptive thresholding. Several morphological features are computed on the segmented venation, and classified using four alternative classifiers, namely support vector machines (linear and Gaussian kernels), penalized discriminant analysis and random forests. The performance is compared to the one obtained with cleared leaves images, which require a more expensive, time consuming and delicate procedure of acquisition. The results are encouraging, showing that the proposed approach is an effective and more economic alternative solution which outperforms the manual expert's recognition.
EEA Oliveros
Author affiliation: Larese, Monica Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas. Universidad Nacional de Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas; Argentina
Author affiliation: Namias, Rafael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas. Universidad Nacional de Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas; Argentina
Author affiliation: Craviotto, Roque Mario. INTA. Estación Experimental Agropecuaria Oliveros; Argentina
Author affiliation: Arango, Miriam Raquel. INTA. Estación Experimental Agropecuaria Oliveros; Argentina
Author affiliation: Gallo, Carina Del Valle. INTA. Estación Experimental Agropecuaria Oliveros; Argentina
Author affiliation: Granitto, Pablo Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas. Universidad Nacional de Rosario. Centro Internacional Franco Argentino de Ciencias de la Información y de Sistemas; Argentina
Keywords: Leguminosas; Nervaduras Foliares; Análisis de Imágenes; Legumes; Leaf Veins; Image Analysis.
Repository: INTA Digital (INTA). Instituto Nacional de Tecnología Agropecuaria
Authors: Amorim, F. W.; Galetto, Leonardo; Sazima, M.
Publication Date: 2012.
Language: English.
Abstract:
Inga species present brush-type flower morphology allowing them to be visited by distinct groups of pollinators. Nectar features in relation to the main pollinators have seldom been studied in this genus. To test the hypothesis of floral adaptation to both diurnal and nocturnal pollinators, we studied the pollination ecology of Inga sessilis, with emphasis on the nectar secretion patterns, effects of sequential removals on nectar production, sugar composition and the role of diurnal and nocturnal pollinators in its reproductive success. Inga sessilis is self-incompatible and pollinated by hummingbirds, hawkmoths and bats. Fruit set under natural conditions is very low despite the fact that most stigmas receive polyads with sufficient pollen to fertilise all ovules in a flower. Nectar secretion starts in the bud stage and flowers continually secreting nectar for a period of 8 h. Flowers actively reabsorbed the nectar a few hours before senescence. Sugar production increased after nectar removal, especially when flowers were drained during the night. Nectar sugar composition changed over flower life span, from sucrose-dominant (just after flower opening, when hummingbirds were the main visitors) to hexose-rich (throughout the night, when bats and hawkmoths were the main visitors). Diurnal pollinators contributed less than nocturnal ones to fruit production, but the former were more constant and reliable visitors through time. Our results indicate I. sessilis has floral adaptations, beyond the morphology, that encompass both diurnal and nocturnal pollinator requirements, suggesting a complementary and mixed pollination system.
Author affiliation: Amorim, F. W.. Universidade Estadual de Campinas; Brasil
Author affiliation: Galetto, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Instituto Multidisciplinario de Biología Vegetal (p); Argentina. Universidad Nacional de Córdoba; Argentina
Author affiliation: Sazima, M.. Universidade Estadual de Campinas; Brasil
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas
Publication Date: 2013.
Language: Spanish.
Abstract:
En el presente trabajo se analizaron los cambios en los atributos reproductivos y vegetativos en plantas de Lotus tenuis sembradas a diferentes densidades. Las plantas fueron cultivadas en condiciones de campo mediante un diseño sistemático cuya disposición permitió obtener 6 densidades comprendidas entre 7,5 y 60,0 pl/m2. Los atributos analizados a nivel de planta como: producción de semillas, biomasa reproductiva, frutos, umbelas con frutos, biomasa total y número de tallos, decrecieron con el aumento de la densidad. La producción de semillas (g/m2) no varió significativamente con la densidad y se explicó mediante la plasticidad fenotípica de los atributos vegetativos y reproductivos de las plantas. El peso de mil semillas fue el atributo menos variable con las densidades. El número de frutos por planta se relacionó de manera lineal y positiva con el número de tallos y la biomasa vegetativa aérea por planta. En tal sentido, manejos del cultivo que permitan aumentar el número de tallos por planta, como por ejemplo los cortes, podrían incidir positivamente sobre el número de ápices reproductivos y el rendimiento. Lotus tenuis puede ser sembrado en un amplio rango de densidades sin afectar significativamente el rendimiento ni la calidad de sus semillas. Sin embargo, de acuerdo con nuestras estimaciones, para alcanzar la mínima biomasa aérea vegetativa por planta consistente con el inicio de la reproducción, la densidad no debería ser superior a 109 pl/m2.
This assay examined the effects of plant densities of Lotus tenuis on reproductive and vegetative attributes. The plants were sowed in field conditions under systematic design which provided 6 plant densities from 7.5 to 60.0 pl/m². The attributes per plant as: seed production, reproductive biomass, pods, umbels with pods, total biomass and stems number decreased according to increase plant densities. Seed yield (g/m²) was relatively stable among plant densities and was explained through the plant phenotypic plasticity of vegetative and reproductive attributes. Thousand-seed weight was less influenced by plant densities. Pods number per plant showed a positive and linear relationship with number of stems per plant and vegetative biomass per plant. Management decisions that increase the reproductive stems number per plant, for example defoliation, may impact positively on the number of reproductive apexes and seed production. Lotus tenuis can be sowed in a range of density without affecting significantly the yield neither the seed quality. Minimum vegetative shoot biomass threshold consistent with plant reproduction is with a plant density lower than 109 pl/m . 2
EEA Balcarce
Author affiliation: Vignolio, Osvaldo. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agriarias; Argentina. INTA. Estación Experimental Agropecuaria Balcarce; Argentina
Author affiliation: Cambareri, Gustavo Sebastián. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agriarias; Argentina. INTA. Estación Experimental Agropecuaria Balcarce; Argentina
Author affiliation: Petigrosso, Lucas R. Universidad Nacional de Mar del Plata. Facultad de Ciencias Agriarias; Argentina. INTA. Estación Experimental Agropecuaria Balcarce; Argentina
Repository: INTA Digital (INTA). Instituto Nacional de Tecnología Agropecuaria
Abstract:
Author affiliation: Fornasero Laura Viviana. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina.
El empleo de leguminosas nativas asociadas a gramíneas constituye un recurso eficiente para mantener el suelo con buenos niveles de fertilidad nitrogenada minimizando el uso de fertilizantes químicos, generalmente costosos y de alto impacto ambiental. En este contexto, las especies de leguminosas forrajeras nativas presentan un gran potencial práctico y un ejemplo de ello es Desmanthus virgatus (L.) Willd. de amplia distribución en el centro norte de Argentina. Hacia el uso sustentable de esta leguminosa, en este trabajo de tesis se presenta la caracterización fenotípica, genotípica y simbiótica de rizobios noduladores del complejo D. virgatus recuperados de suelos argentinos. Para ello, se seleccionaron y colectaron 10 poblaciones de plantas de D. virgatus (sensu lato) en diferentes ambientes y se estableció una colección de más de 170 aislamientos de rizobios noduladores. La caracterización fenotípica de los simbiontes permitió reconocer rizobios de crecimiento rápido con capacidad de crecer en condiciones que se consideran adversas y que sugieren una mayor flexibilidad fisiológica y capacidad de adaptación al ambiente. Los perfiles de amplificación de ADN genómico (fingerprints) evidenciaron una marcada diversidad genética entre los aislamientos. Con respecto a las características simbióticas, se hallaron rizobios con muy buena capacidad potencial de fijación biológica de nitrógeno y competencia por el nicho simbiótico. Los resultados presentados enfatizan la importancia de la inoculación con cepas eficientes y adaptadas a nuestras condiciones edafoclimáticas para lograr un establecimiento exitoso y crecimiento inicial adecuado de las plántulas de D. virgatus en condiciones de campo.
The use of grass-associated native legumes is an efficient resource in order to keep good nitrogen fertility levels in the soil, minimizing the use of chemical fertilizers, which are usually expensive and of high environmental impact. In this context, the native forage legumes species have great practical potential, an example being Desmanthus virgatus (L.) Willd widely distributed in the central northern area of Argentina. Toward sustainable use of this legume, this thesis paper includes a phenotypic, genotypic and symbiotic characterization of D. virgatus complex rhizobia nodulators retrieved from Argentinian soils. For that, ten populations of D. virgatus plants (sensu lato) were selected and collected from different environments. A collection of over 170 isolations of D. virgatus complex rhizobia nodulators was generated. The phenotypic characterization of the symbionts allowed for the recognition of rapid growth rhizobia that showed a capacity for growth in conditions deemed adverse and which suggest a higher physiological flexibility and an ability to adapt to environmental. The genomic DNA amplification profiling (fingerprints) exhibited a clear genetic diversity amongst the isolations. Regarding the symbiotic characteristics, rhizobia with a great potential for biological nitrogen fixation and competition for the symbiotic niche were found. The results presented here emphasize the importance of using efficient strains adapted to our edaphoclimatic conditions for inoculation in order to achieve a successful establishment and a proper early growth of the D. virgatus seedlings in field conditions.
Universidad Nacional del Litoral
Repository: Biblioteca Virtual (UNL). Universidad Nacional del Litoral
Authors: Oelbermann, Maren; Regehr, Alison; Echarte, Laura
Publication Date: 2015.
Language: English.
Abstract:
The Argentine Pampa is one of the most productive agricultural regions in the world, but sole crop management practices have led to soil degradation and losses of soil organic matter. The objective of this study was to evaluate soil organic carbon (SOC) and nitrogen (N) dynamics in 2007 and in 2012 in two intercrop systems [1:2 intercrop (one row of maize (Zea mays L.) and two rows of soybeans (Glycine max L. Merr.)) and 2:3 intercrop (two rows of maize and three rows of soybean)], and in a maize and soybean sole crop. Results showed that C and N input from crop residues was significantly greater (P < 0.05) in the maize sole crop, followed by the intercrops and the soybean sole crop. The land equivalent ratio (LER), based on crop biomass, was significantly greater (P < 0.05) in the 2:3 intercrop. Soil physical and chemical characteristics (bulk density, pH, SOC and N, C/N ratio) were not significantly (P < 0.05) different among treatments and were significantly greater in 2012, except for pH, at all depths. Gross SOC turnover time was significantly longer (P < 0.05) in 2012 compared to 2007 for all treatments and depths, except in the maize sole crop. Soil microbial biomass (SMB) C and N were significantly greater (P < 0.05) in the 2:3 intercrop in both years. To a 40 cm depth, SMB-C turnover time (SMB-CT) was significantly greater (P < 0.05) in the soybean sole crop followed by the intercrops and the maize sole crop in 2007, whereas in 2012, SMB-CT was significantly greater (P < 0.05) in the intercrops followed by the soybean and the maize sole crops. The soil light fraction N (LF-N) was significantly greater (P < 0.05) in the maize sole crop in both years. There was no significant difference (P < 0.05) for LF-C. Our results demonstrated that cereal–legume intercropping is a more sustainable agroecosystem land management practice in the Argentine Pampa, with respect to soil C and N transformations, compared to sole cropping.
EEA Balcarce
Author affiliation: Oelbermann, Maren. University of Waterloo. Department of Environment and Resource Studies; Canadá
Author affiliation: Regehr, Alison. University of Waterloo. Department of Environment and Resource Studies; Canadá
Author affiliation: Echarte, Laura. INTA. Estación Experimental Agropecuaria Balcarce; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina
Repository: INTA Digital (INTA). Instituto Nacional de Tecnología Agropecuaria