Variability for salt tolerance in a collection of <i>Panicum coloratum</i> var. <i>makarikariense</i> during early growth stages

Our aim was to investigate variability for salt tolerance in a collection of Panicum coloratum var. makarikariense of INTA EEA Rafaela, Argentina. Panicum coloratum is a C4 perennial grass to be potentially used to increase forage production in areas affected by abiotic factors which reduce their productivity. We evaluated the response of half-sib families from different accessions to increasing salt concentrations under growth chamber conditions. Germination percentage (GP), GP (% of control) and index of germination decreased with increasing salinity, while mean germination time increased (P˂0.001). After being exposed to saline conditions ungerminated seeds were able to recover in distilled water and many germinated. Salt tolerance was more variable between families within accessions than between accessions in all evaluated variables. At the seedling stage, morphological and physiological variables allowed differentiation among families on the basis of salt tolerance. Molecular characterization by ISSR molecular markers demonstrated variability within parent material and grouped families by accessions. A positive but low correlation between morphological and molecular distances was detected (r = 0.24; P = 0.032). Nonetheless, even after selection, enough molecular variability remained within tolerant families grouped by principal components analysis. In summary, materials of P. coloratum var. makarikariense from INTA EEA Rafaela showed both morphological and genetic variability for salinity tolerance and the contrasting genotypes could be used as parent materials to conduct breeding studies to improve salt tolerance in this species

Asociación entre prácticas de ordeño y recuento de organismos psicrótrofos en leche de tanque de frío

The objective of this work was to determine on-farm risk factors for psychrotrophic bacterial counts in bulk tank milk from dairy farms in Argentina. Raw milk samples from bulk tanks of 27 dairy farms were examined for total psychrotrophic counts (TPC), proteolytic psychrotrophic counts (PPC) and lipolytic psychrotrophic counts (LPC) (dependent or outcome variables). A survey recording infrastructure conditions, milking equipment and milking management (independent variables) was performed. Bivariate association proofs and logistic regression analyses were used to determine association between independent variables and psychrotrophic bacterial counts. Milk cooled in plate heat exchangers or barrel tanks were 16.39 and 10.52 times more likely to yield TPC and PPC above the standard established for high quality milk compared with milk cooled in bulk tanks, respectively. Periodic cleaning of cooling tanks (3 times a week or daily) was associated with lower TPC (approximately 1.5 log CFU/ml) than weekly cleaning frequency and farms where milkers did not wash their hands during milking time were 7.81 times more likely to have higher PPC. No association was found between LPC and any of the independent variables. The only variable associated with TPC and PPC in a logistic regression model was the refrigeration system used on the farm. Dairy farms that possessed bulk milk cooling tanks yielded the lowest bacterial counts. Results of this study highlight the importance of both the type of cooling system used on the farm and its adequate hygienic maintenance for obtaining low pshychrotrophic counts at dairy farm.El objetivo del trabajo fue determinar los factores de riesgo para altos recuentos de organismos psicrótrofos en leche de tanques de tambos de la Argentina. Se examinaron muestras de leche cruda de tanques de frío de 27 tambos, y se realizó el recuento de organismos psicrótrofos totales (PT), de psicrótrofos proteolíticos (PP) y de psicrótrofos lipolíticos (PL) (variables dependientes). Se realizó una encuesta para registrar las condiciones de infraestructura, el equipo de ordeño y las prácticas de ordeño (variables independientes). Se utilizaron pruebas bivariadas de asociación y regresión logística para determinar la asociación entre las variables independientes y los recuentos de organismos psicrótrofos. La leche enfriada en sistemas de placas de intercambio o tanques tipo cuba tuvo una probabilidad mayor de dar recuentos elevados de PT y PP (16,39 y 10,52) comparada con la enfriada en tanques tipo "panza fría". La limpieza periódica del equipo de frío (3 veces por semana o diariamente) se asoció con bajos recuentos de PT (aproximadamente 1,5 log de UFC/ml). Los tambos cuyos ordeñadores no se higienizaban las manos durante el ordeño tuvieron una probabilidad 7,81 veces mayor de tener recuentos elevados de PP. No se encontró asociación entre el recuento de PL y las variables independientes. La única variable asociada con los recuentos de PT y PP en el modelo de regresión logística fue el sistema de enfriamiento utilizado en el tambo. El tipo de sistema de refrigeración usado y su adecuado mantenimiento higiénico son importantes para la obtención de leche con baja carga de organismos psicrótrofos en el tambo.Fil: Molineri, Ana Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación de la Cadena Láctea. - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela. Instituto de Investigación de la Cadena Láctea; ArgentinaFil: Signorini Porchietto, Marcelo Lisandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación de la Cadena Láctea. - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela. Instituto de Investigación de la Cadena Láctea; Argentina. Universidad Nacional del Litoral; ArgentinaFil: Cuatrín, Alejandra L.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Canavesio, Vilma R.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Neder, Veronica. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Russi, Norma B.. Universidad Nacional del Litoral; ArgentinaFil: Bonazza, Julio C.. Universidad Nacional del Litoral; ArgentinaFil: Calvinho, Luis F.. Universidad Nacional del Litoral; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentin

Honey produced in a dairy farming system based on alfalfa (physicochemical, palynologic and sensorial analyses)

The objective of this study was to characterize honey produced in the central area of Santa Fe province, Argentina. Honey samples (134, produced from 2005/2006 to 2009/2010), considered by farmers to be single-flowered of clover or alfalfa were analyzed physicochemically, palynologically and sensorial analyses. Thirty-six botanic families were identified in the samples, but only 5 families were observed in &gt;50% of them. Alfalfa (Medicago sativa) was found in 72% of the samples; however, its pollen was of minor importance in 81% of the cases. Clover pollen (Trifolium sp and, Melilotus sp.) associated with that of alfalfa (Medicago sativa) and Lotus sp was observed in 89% of the samples, but in only 8% of the cases was its concentration &gt;45%, the percentage required to be considered as clover single-flowered honey, according to the National Legislation. When clover, alfalfa and lotus pollen constituted 20% or more of the total pollen, chemical and sensorial changes were observed and non-significant differences were observed between kinds of honey with 20-45% and those with &gt;45% of this pollen. Honey with 20% of clover pollen showed lower humidity, color, acidity, glucose and fructose in comparison with the honey of &lt;20% clover pollen). The presence of at least 20% of this pollen imparted a warm subtle and plant dry smell, warm subtle aroma, pungent trigeminal sensation and a fluid oral texture. Presence of at least 20% of clover, alfalfa and lotus pollen induces changes in the honey characteristics of the region studied

Asociación entre prácticas de ordeño y recuento de organismos psicrótrofos en leche de tanque de frío

The objective of this work was to determine on-farm risk factors for psychrotrophic bacterial counts in bulk tank milk from dairy farms in Argentina. Raw milk samples from bulk tanks of 27 dairy farms were examined for total psychrotrophic counts (TPC), proteolytic psychrotrophic counts (PPC) and lipolytic psychrotrophic counts (LPC) (dependent or outcome variables). A survey recording infrastructure conditions, milking equipment and milking management (independent variables) was performed. Bivariate association proofs and logistic regression analyses were used to determine association between independent variables and psychrotrophic bacterial counts. Milk cooled in plate heat exchangers or barrel tanks were 16.39 and 10.52 times more likely to yield TPC and PPC above the standard established for high quality milk compared with milk cooled in bulk tanks, respectively. Periodic cleaning of cooling tanks (3 times a week or daily) was associated with lower TPC (approximately 1.5 log CFU/ml) than weekly cleaning frequency and farms where milkers did not wash their hands during milking time were 7.81 times more likely to have higher PPC. No association was found between LPC and any of the independent variables. The only variable associated with TPC and PPC in a logistic regression model was the refrigeration system used on the farm. Dairy farms that possessed bulk milk cooling tanks yielded the lowest bacterial counts. Results of this study highlight the importance of both the type of cooling system used on the farm and its adequate hygienic maintenance for obtaining low pshychrotrophic counts at dairy farm.El objetivo del trabajo fue determinar los factores de riesgo para altos recuentos de organismos psicrótrofos en leche de tanques de tambos de la Argentina. Se examinaron muestras de leche cruda de tanques de frío de 27 tambos, y se realizó el recuento de organismos psicrótrofos totales (PT), de psicrótrofos proteolíticos (PP) y de psicrótrofos lipolíticos (PL) (variables dependientes). Se realizó una encuesta para registrar las condiciones de infraestructura, el equipo de ordeño y las prácticas de ordeño (variables independientes). Se utilizaron pruebas bivariadas de asociación y regresión logística para determinar la asociación entre las variables independientes y los recuentos de organismos psicrótrofos. La leche enfriada en sistemas de placas de intercambio o tanques tipo cuba tuvo una probabilidad mayor de dar recuentos elevados de PT y PP (16,39 y 10,52) comparada con la enfriada en tanques tipo "panza fría". La limpieza periódica del equipo de frío (3 veces por semana o diariamente) se asoció con bajos recuentos de PT (aproximadamente 1,5 log de UFC/ml). Los tambos cuyos ordeñadores no se higienizaban las manos durante el ordeño tuvieron una probabilidad 7,81 veces mayor de tener recuentos elevados de PP. No se encontró asociación entre el recuento de PL y las variables independientes. La única variable asociada con los recuentos de PT y PP en el modelo de regresión logística fue el sistema de enfriamiento utilizado en el tambo. El tipo de sistema de refrigeración usado y su adecuado mantenimiento higiénico son importantes para la obtención de leche con baja carga de organismos psicrótrofos en el tambo.Fil: Molineri, Ana Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación de la Cadena Láctea. - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela. Instituto de Investigación de la Cadena Láctea; ArgentinaFil: Signorini Porchietto, Marcelo Lisandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación de la Cadena Láctea. - Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela. Instituto de Investigación de la Cadena Láctea; Argentina. Universidad Nacional del Litoral; ArgentinaFil: Cuatrín, Alejandra L.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Canavesio, Vilma R.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Neder, Veronica. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; ArgentinaFil: Russi, Norma B.. Universidad Nacional del Litoral; ArgentinaFil: Bonazza, Julio C.. Universidad Nacional del Litoral; ArgentinaFil: Calvinho, Luis F.. Universidad Nacional del Litoral; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Santa Fe. Estación Experimental Agropecuaria Rafaela; Argentin

Nitrogen fertilization effects on forage production and nutritive value of 4 tropical grasses on alkaline soils in Argentina

This study evaluated effects of nitrogen (N) fertilization and gypsum application and their interactions on total pasture forage production and nutritive values of Chloris gayana cultivars ‘Santana’ and ‘Finecut’ and Panicum coloratum cultivars ‘Klein’ and ‘Bambatsi’ growing in a moderately sodic soil (Typic Natracualf) in northcentral Santa Fe Province of Argentina over 3 years. Sown pasture forage production differed among cultivars. C. gayana cultivar ‘Finecut’ produced more forage biomass than the other 3 cultivars. P. coloratum cultivars were superior to C. gayana cultivars for nutritive value, showing lower NDF and ADF. N fertilization strongly increased forage production, total biomass and sown pasture biomass with improved crude protein content and improvement in plant N status. Addition of gypsum did not affect forage production and nutritive value. This research showed the feasibility to improve production and nutritive value of tropical pastures in subtropical areas by species/cultivar selection and N fertilization

Identification of Molecular Markers and Candidate Genes Associated with Time to Flowering and Length of Reproductive Period in Soybean Through Association Mapping

Adaptation to temporal stress can be achieved by modifying flowering time and lengthening the reproductive period. To identify genotypes, molecular markers, and genes related with these traits, a set of 94 soybeans were genotyped using 7125 SNPs and 6465 DArTs. The genotypes were grouped according to their duration cycle (cycle) and were analyzed, days from emergence to beginning bloom (E–R1), days from beginning bloom to beginning pod (R1–R3), and days from beginning pod to full seed (R3–R6), identifying fifty-six genotypes with short E–R1 (Sh.E–R1) and/or prolonged R1–R3 and R3–R6 (L.R1–R3 and L.R3–R6). The population structure determined with 14 SSR markers that best adjusted was K = 2. For a total of 203 markers associated with Sh.E–R1, L.R1–R3, and L.R3–R6, 1221 candidate genes were identified, of which 17 were previously cited and/or containing markers located in their sequence and were selected for future studies. Splitting the reproductive period in two phases allowed the detection of variability through it. It was verified the existence of genotypes with early bloom and/or prolonged reproductive period within germplasm with similar cycle. The genotypes identified, molecular markers, and associated genes can be used in breeding programs to extend the reproductive period in soybean.Fil: Vicentin, Ignacio Gabriel. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Entre Ríos. Estación Experimental Agropecuaria Paraná; ArgentinaFil: Ghione, Celina Elena. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Cuatrín, Alejandra. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Entre Ríos. Estación Experimental Agropecuaria Paraná; ArgentinaFil: Gilli, Javier Ramón. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Bernardi, Clarisa Noelia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Córdoba. Estación Experimental Agropecuaria Marcos Juárez; ArgentinaFil: Darío, De Lucia Adrián. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Misiones. Estación Experimental Agropecuaria Cerro Azul; ArgentinaFil: Heinz, Ruth Amelia. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular; Argentin