9 research outputs found

    Reproductive traits and floral visitors of Aechmea distichantha plants growing in different habitats of a South American xerophytic forest

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    Aechmea distichantha, a widely-distributed facultative epiphytic bromeliad species, is present from rainforests to xerophytic forests. At its southernmost distribution (Humid Chaco) it grows in the understory and forest edges. This animal-pollinated bromeliad shows high phenotypic plasticity on its vegetative traits, but there is no information about plasticity on its reproductive traits. Infructescences from shade plants were heavier, had longer rachis, more spikelets, higher number of fruits/spikelet and higher number of seeds/fruit than those from sun plants, but they presented similar number of open flowers. The number of visitation events was similar in both habitats, but more flowers were visited in the sun than in the shade. Flowers were visited by seven species (six insects and one hummingbird). In the sun, the carpenter bee was the most frequent visitor and visited almost all flowers, whereas in the shade different species of visitors attained similar proportion of visits and number of visited flowers. Despite visitation events were similar in both habitats, plants growing in the shade set more seeds/fruit than plants growing in the sun. The higher proportion of visits accomplished by carpenter bees compared to hummingbirds is probably a consequence of the climatic conditions in the austral location of these populations.Universidad Nacional de Rosario, Facultad de Ciencias Agrarias, Cátedra de Ecología, Campo Experimental J.F. Villarino, S2125ZAA Zavalla, Santa Fe, Argentina Instituto de Investigaciones en Ciencias Agrarias - CONICET, Campo experimental J.F. Villarino, S2125ZAA, Zavalla, Argentin

    Distribution of vascular epiphytes on four tree species in a xerophytic forest of the wet chaco, Argentina

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    Las epífitas aportan una gran diversidad específica y brindan numerosos servicios ecosistémicos en los bosques. En el Chaco Húmedo, los estudios sobre epífitas son muy escasos, por lo cual se realizó una descripción de la comunidad de epífitas vasculares de cuatro especies arbóreas deciduas representativas de un quebrachal de la Cuña Boscosa Santafesina. Dos especies pertenecen al estrato superior (Schinopsis balansae y Sideroxylon obtusifolium) y dos al inferior (Prosopis spp. y Acacia praecox). En invierno se seleccionaron al azar ocho individuos de cada especie y cada uno fue dividido en cuatro zonas (Zona I-II: tronco principal; Zona III: bases de las ramas; Zona IV: parte media de las ramas; Zona V: ramas más finas). En cada zona se contaron e identificaron a nivel de especie todas las epífitas vasculares. En la Zona V se diferenciaron ramas vivas y secas. Los datos se analizaron estadísticamente con modelos lineales generalizados mixtos y análisismultivariados. Se registraron 14 especies (nueve holoepífitas, dos facultativas y tres accidentales) de cuatro familias (Bromeliaceae, Cactaceae, Polypodiaceae y Anacardiaceae). La familia Bromeliaceae fue la más rica, con siete especies del género Tillandsia y Aechmea distichantha. La especie más abundante fue Tillandsia recurvata.Prosopis spp. tuvo la mayor abundancia de epífitas y S. obtusifolium la mayor riqueza. La Zona V tuvo mayor abundancia y riqueza de epífitas en promedio que las otras zonas. Se observaron diferencias cuantitativas entre forófitos en la composición de especies: A. distichantha y T. loliacea estuvieron asociadas positivamente con S. obtusifolium. Prosopis spp. tuvo mayor abundancia y riqueza de epífitas en ramas secas, y los forófitos del estratosuperior, en ramas vivas. Las diferencias en abundancia, riqueza, composición específica y distribución vertical de epifitas entre forófitos podrían atribuirse a sus características morfológicas y a la variedad de microhábitats en el tronco y las ramas.In numerous forests, the vascular epiphytes contribute substantially to species diversity. Studies about vascular epiphytes in the Wet Chaco region are very scarce. We carried out a description of the epiphyte community in four deciduous tree species, representative of a quebrachal of the Cuña Boscosa Santafesina: two of them from the upper stratum (Schinopsis balansae and Sideroxylon obtusifolium) and two from the lower one (Acacia praecox and Prosopis spp.). Eight individuals of each tree species were selected, and each individual was divided in four zones (Zone I-II: main trunk; Zone III: basal branches; Zone IV: middle branches; Zone V: thinnest branches). For each zone, all the vascular epiphytes were counted and identified at species level. In Zone V, living and dead branches were differentiated. Data were analyzed with general linear mixed models and multivariate analysis. Fourteen species of vascular epiphytes were recorded (nine holoepiphytes, two facultative and three accidental epiphytic species) of four families (Bromeliaceae, Cactaceae, Polypodiaceae and Anacardiaceae). The richest family was Bromeliaceae, with seven species of the genus Tillandsia and Aechmea distichantha. The most abundant species was Tillandsia recurvata. Prosopis spp. had the highest abundance of epiphytes and S. obtusifolium the highest richness. Zone V had the highest average abundance and richness of vascular epiphytes. There were quantitative differences in species composition between phorophytes: A. distichantha and T. loliacea were positively associated with S. obtusifolium. Prosopis spp. had the highest abundance and richness in dead branches and the phorophytes of the upper stratum in the living ones. The differences in abundance, richness, specific composition and vertical distribution of vascular epiphytes between phorophytes could be attributed to their morphological characteristics and the microhabitats conditions in the trunk and branches.Fil: Alvarez Arnesi, Eugenio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Barberis, Ignacio Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Vesprini, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentin

    Adding 6 months of androgen deprivation therapy to postoperative radiotherapy for prostate cancer: a comparison of short-course versus no androgen deprivation therapy in the RADICALS-HD randomised controlled trial

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    Background Previous evidence indicates that adjuvant, short-course androgen deprivation therapy (ADT) improves metastasis-free survival when given with primary radiotherapy for intermediate-risk and high-risk localised prostate cancer. However, the value of ADT with postoperative radiotherapy after radical prostatectomy is unclear. Methods RADICALS-HD was an international randomised controlled trial to test the efficacy of ADT used in combination with postoperative radiotherapy for prostate cancer. Key eligibility criteria were indication for radiotherapy after radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to radiotherapy alone (no ADT) or radiotherapy with 6 months of ADT (short-course ADT), using monthly subcutaneous gonadotropin-releasing hormone analogue injections, daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as distant metastasis arising from prostate cancer or death from any cause. Standard survival analysis methods were used, accounting for randomisation stratification factors. The trial had 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 80% to 86% (hazard ratio [HR] 0·67). Analyses followed the intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov, NCT00541047. Findings Between Nov 22, 2007, and June 29, 2015, 1480 patients (median age 66 years [IQR 61–69]) were randomly assigned to receive no ADT (n=737) or short-course ADT (n=743) in addition to postoperative radiotherapy at 121 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 9·0 years (IQR 7·1–10·1), metastasis-free survival events were reported for 268 participants (142 in the no ADT group and 126 in the short-course ADT group; HR 0·886 [95% CI 0·688–1·140], p=0·35). 10-year metastasis-free survival was 79·2% (95% CI 75·4–82·5) in the no ADT group and 80·4% (76·6–83·6) in the short-course ADT group. Toxicity of grade 3 or higher was reported for 121 (17%) of 737 participants in the no ADT group and 100 (14%) of 743 in the short-course ADT group (p=0·15), with no treatment-related deaths. Interpretation Metastatic disease is uncommon following postoperative bed radiotherapy after radical prostatectomy. Adding 6 months of ADT to this radiotherapy did not improve metastasis-free survival compared with no ADT. These findings do not support the use of short-course ADT with postoperative radiotherapy in this patient population

    Duration of androgen deprivation therapy with postoperative radiotherapy for prostate cancer: a comparison of long-course versus short-course androgen deprivation therapy in the RADICALS-HD randomised trial

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    Background Previous evidence supports androgen deprivation therapy (ADT) with primary radiotherapy as initial treatment for intermediate-risk and high-risk localised prostate cancer. However, the use and optimal duration of ADT with postoperative radiotherapy after radical prostatectomy remains uncertain. Methods RADICALS-HD was a randomised controlled trial of ADT duration within the RADICALS protocol. Here, we report on the comparison of short-course versus long-course ADT. Key eligibility criteria were indication for radiotherapy after previous radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to add 6 months of ADT (short-course ADT) or 24 months of ADT (long-course ADT) to radiotherapy, using subcutaneous gonadotrophin-releasing hormone analogue (monthly in the short-course ADT group and 3-monthly in the long-course ADT group), daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as metastasis arising from prostate cancer or death from any cause. The comparison had more than 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 75% to 81% (hazard ratio [HR] 0·72). Standard time-to-event analyses were used. Analyses followed intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov , NCT00541047 . Findings Between Jan 30, 2008, and July 7, 2015, 1523 patients (median age 65 years, IQR 60–69) were randomly assigned to receive short-course ADT (n=761) or long-course ADT (n=762) in addition to postoperative radiotherapy at 138 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 8·9 years (7·0–10·0), 313 metastasis-free survival events were reported overall (174 in the short-course ADT group and 139 in the long-course ADT group; HR 0·773 [95% CI 0·612–0·975]; p=0·029). 10-year metastasis-free survival was 71·9% (95% CI 67·6–75·7) in the short-course ADT group and 78·1% (74·2–81·5) in the long-course ADT group. Toxicity of grade 3 or higher was reported for 105 (14%) of 753 participants in the short-course ADT group and 142 (19%) of 757 participants in the long-course ADT group (p=0·025), with no treatment-related deaths. Interpretation Compared with adding 6 months of ADT, adding 24 months of ADT improved metastasis-free survival in people receiving postoperative radiotherapy. For individuals who can accept the additional duration of adverse effects, long-course ADT should be offered with postoperative radiotherapy. Funding Cancer Research UK, UK Research and Innovation (formerly Medical Research Council), and Canadian Cancer Society

    Entomofilia in due specie a fioritura invernale

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    Dottorato di ricerca in biologia animale (zoologia). 12. ciclo. A.a. 1999-2000. Coordinatore R. Dallai. Supervisore E. PaciniConsiglio Nazionale delle Ricerche - Biblioteca Centrale - P.le Aldo Moro, 7, Rome; Biblioteca Nazionale Centrale - P.za Cavalleggeri, 1, Florence / CNR - Consiglio Nazionale delle RichercheSIGLEITItal

    Contrasting breeding systems in six species of Tillandsia L. (Bromeliaceae) from woody areas of Santa Fe Province: Argentina

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    The reproductive biology of six native Tillandsia species that co-occurred in woody areas of Santa Fe Province (Argentina) was studied for floral biology, breeding systems and reproductive success. Flower longevity, floral phases, hand self- and cross-pollinations or natural pollinations and fluorescence microscopy observations of post-pollination events were analysed. Also pollen/ovule (P/O) ratio and pre-emergent reproductive success (PERS) were compared between species. In T. ae¨ranthos, T. ixioides and T. meridionalis, self-pollinated flowers mostly failed to form fruits, and fluorescence microscopy studies showed that in selfed pistils pollen tube growth was arrested in the style. It is likely that these species have homomorphic, gametophytic self-incompatibility. In contrast, T. capillaris, T. tricholepis and T. recurvata regularly formed fruits following autonomous self-pollination. Floral traits, the P/O ratios and PERS indices correlate with the breeding systems found in these two groups of species: the three selfing species have inconspicuous closed flowers, and they have low P/O ratios and high PERS values. In contrast, the three self-incompatible (SI) species have conspicuous flowers with relatively high P/O and low PERS values. We described here three new cases of SI in Tillandsia species subgenera Anoplophytum and confirm the autogamous and cleistogamous status in three species of Tillandsia subgenera DiaphoranthemaFil: Bianchi, Marta Beatriz. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; ArgentinaFil: Vesprini, Jose Luis. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    The beneficial effect of ants on the reproductive success of Dyckia floribunda (Bromeliaceae), an extrafloral nectary plant

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    Dyckia floribunda is a perennial herb from the Argentinian Chaco with extrafloral nectaries. Ants visited these nectaries while patrolling inflorescences and infructescences. We anticipated that ants attracted to extrafloral nectaries might protect the reproductive organs, increasing plant reproductive output. To evaluate the possibility of mutualism between D. floribunda and ant visitors, we determined whether ant-accessible plants showed a higher seed production than ant-excluded plants. Experimental fieldwork suggested a decrease in fruit set of ant-excluded plants compared with ant-accessible plants but the seed number per fruit was not affected by ant exclusion. Thus, total seed number per plant was highly reduced in treated spikes. Analyses of covariance confirmed these trends, indicating that total seed production per plant was strongly affected by ant exclusion. This study marks the first experimental report of this mutualistic association in Bromeliaceae.Le Dyckia floribunda, une herbacée pérenne du Chaco en Argentine, possède des nectaires extra-floraux. Les fourmis visitent ces nectaires en faisant le tour des inflorescences et des infructescences. Les auteurs ont formulé l’hypothèse que les nectaires extra-floraux pourraient protéger les organes reproducteurs et ainsi augmenter le succès reproductif. Afin d’évaluer l’existence de mutualisme entre le D. floribunda et les fourmis visiteuses, les auteurs ont vérifié si des plants accessibles aux fourmis produisent plus de graines que des plants non-accessibles aux fourmis. Le travail au champ indique qu’il y aurait une diminution de la mise à fruit chez les plants privés de fourmis, comparativement aux plants visités par les fourmis, mais le nombre de graines par plant n’est pas affecté. Tout de même le nombre total de graines par plant se voit diminué dans les épis traités. L’analyse de covariance confirme ces tendances et indique que la production totale de graines par plant est fortement affectée par l’exclusion des fourmis. Il s’agit de la première démonstration expérimentale de cette association mutualiste chez les Bromeliaceae.Fil: Vesprini, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Galetto, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Bernardello, Gabriel Luis Mario. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

    Pollination service and soybean yields

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    Soybean is the most important crop for Argentina in terms of cultivated area and annually exported tons. Although soybean is autogamous, crop yields can be enhanced by pollinators. The aim of this study is to analyze the effects of insect pollination on soybean production. A pollination exclusion experiment (15 replications) was conducted to analyze the effects on seed production per plant in three stands located in the adjacence to a 100 Ha forested park, which was considered the main potential source of wild pollinators to soybean flowers. Fruits and seeds produced per plant –controlled by vegetative growth-were compared between plants with flowers open to pollinators and fully-caged plants (with flowers excluded from pollinators). A control treatment for the shading effect of the cages used for pollinator exclusion was also performed. Pollination was estimated by pollen deposited on stigmas. The number of pollen grains deposited on stigmas of open-pollinated flowers was higher than that of excluded flowers (27.3 vs 6.9 pollen grains per stigma, respectively). Reproductive variables (# of fruits and # of seeds per plant; total yield per plant) showed lower values (13–25% of reduction according to the variable) in excluded flowers compared to those from open-pollinated flowers. The contribution of biotic pollination to soybean production could be important because when pollinators are excluded pollen deposition and crop yields decrease. The soybean pollination service could be considered as part of the green infrastructure needed to maintain or to improve soybean yields.Fil: Santone, Antonella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Mazzei, Mariana Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Vesprini, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; ArgentinaFil: Torres, Carolina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Amarilla, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Galetto, Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

    Optimization of DNA extraction and PCR protocols for phylogenetic analysis in Schinopsis spp. and related Anacardiaceae

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    The Anacardiaceae is an important and worldwide distributed family of ecological and socio-economic relevance. Notwithstanding that, molecular studies in this family are scarce and problematic because of the particularly high concentration of secondary metabolites—i.e. tannins and oleoresins—that are present in almost all tissues of the many members of the group, which complicate the purification and amplification of the DNA. The objective of this work was to improve an available DNA isolation method for Schinopsis spp. and other related Anacardiaceae, as well as the PCR protocols for DNA amplification of the chloroplast trnL-F, rps16 and ndhF and nuclear ITS–ETS fragments. The modifications proposed allowed the extraction of 70–120 µg of non-degraded genomic DNA per gram of dry tissue that resulted useful for PCR amplification. PCR reactions produced the expected fragments that could be directly sequenced. Sequence analyses of amplicons showed similarity with the corresponding Schinopsis accessions available at GenBank. The methodology presented here can be routinely applied for molecular studies of the group aimed to clarify not only aspects on the molecular biology but also the taxonomy and phylogeny of this fascinating group of vascular plants.Fil: Mogni, Virginia Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; ArgentinaFil: Kahan, Mariano Ariel. SINERGIUM Biotech; ArgentinaFil: de Queiroz, Luciano Paganucci. Universidade Estadual de Feira de Santana; BrasilFil: Vesprini, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; ArgentinaFil: Ortiz, Juan Pablo Amelio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; ArgentinaFil: Prado, Darien Eros. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Investigaciones en Ciencias Agrarias de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias. Instituto de Investigaciones en Ciencias Agrarias de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentin
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