ABSTRACT The wild pepper (Capsicum annuum L. var. glabriusculum (Dunal) Heiser & Pickersgill) is a valuable genetic resource for agriculture and food. Around the world salinity is a significant environmental stress that limit and affect agriculture productivity. This work estimates the variation in salinity tolerance in six populations of wild pepper populations of the Northwest of Mexico at three salinity levels (without NaCl, 25 and 50 mM NaCl). The measured traits were height, stem development, foliar area, relative content of chlorophyll, dry weight of plant, root, stem, and leaves. Salinity tolerance was estimated with a stress tolerance index (STI) obtained by comparing values of traits between control treatment (without NaCl) and salinity treatments. Data were subjected to univariate and multivariate variance analysis of principal components. All measured traits were negatively and significantly affected by salinity. Univariate variance analysis and of principal components clearly differentiated the studied populations. At 50 mM NaCl, height, stem diameter, foliar area, stem and leaves dry weight correlated positively with electrical conductivity, and foliar area, relative content of chlorophyll, stem and leaves dry weight correlated with soil Na at the site of origin of the populations. Presa Oviachic showed a higher salinity tolerance in both NaCl treatments (1.17 and 0.99), followed by two more populations (Lo de Vega and Yecorato), each with each salinity treatment. Presa Oviachic presented the highest average STI in both treatments, 37.6% and 40.4% higher than Cósala and Mazocahui respectively. Root dry weight (0.427), stem diameter (0.419), leaf area (0.412), stem dry weight (0.407) and plant dry weight (0.345) were the most important traits in that order and Presa Oviachic was significantly superior to the rest of populations in STI at 50 mM NaCl. Plants of these populations could be a source of salinity resistance. The variation pattern observed in these traits suggests adaptation to the local edaphic conditions.

Resumen El objetivo de este estudio fue evaluar las propiedades fisicoquímicas, morfológicas, estructurales y térmicas del almidón recuperado de los residuos de Solanum tuberosum de la industria de frituras en México, utilizando técnicas instrumentales avanzadas. La papa residual se recogió de una empresa productora de papas fritas y el almidón se obtuvo mediante extracción acuosa. El almidón presentó un contenido de carbohidratos de 87.79 %, proteínas (1.18 %), lípidos (0.15 %), cenizas (0.26 %) y amilosa (24.35 %). La capacidad de absorción de agua fue de 1.0163 g g-1, solubilidad (30.17 - 46.65 %), hinchamiento (2.31 - 8.69 g g-1). Los análisis térmicos mostraron una gelatinización del almidón entre 61.7 - 90 °C con una pérdida máxima de peso a 288.1 °C. La microscopía electrónica de barrido-espectroscopía dispersiva de energía (SEM-EDS) mostró partículas de 14 - 69 µm con una composición de 54.3 % de carbono, 45.4 % de oxígeno y 0.15 % de potasio. La dispersión dinámica de luz (DLS) mostró partículas de tamaño nanométrico (120 nm). La resonancia magnética nuclear (NMR) y la difracción de rayos X (XRD) exhibieron la cristalinidad del almidón como tipo B (34.73 %) y la reflectancia total atenuada por espectroscopia infrarroja transformada de Fourier (FTIR - ATR) mostró los grupos funcionales distintivos de la glucosa.

Abstract The objective of this study was to evaluate the physicochemical, morphological, structural, and thermal properties of starch recovered from Solanum tuberosum residual of chips industry in Mexico using advanced instrumental techniques. The residual potato was collected from a chips production company and the starch obtained by aqueous extraction. The starch presented a content of carbohydrates of 87.79 %, proteins (1.18 %), lipids (0.15 %), ashes (0.26 %), and amylose (24.35 %). The water absorption capacity was 1.0163 g g-1, solubility (30.17 - 46.65 %), swelling (2.31 - 8.69 g g-1). Thermal analyzes showed a starch gelatinization about 61.7 - 90 ºC with a maximum weight loss at 288.1 °C. The scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) showed particles of 14 - 69 µm with a composition of 54.3 % carbon, 45.4 % oxygen, and 0.15 % potassium. The dynamic light scattering (DLS) showed particles of nanometric size (120 nm). The nuclear magnetic resonance (NMR) and X-Ray diffraction (XRD) exhibited the crystallinity of the starch as type B (34.73 %) and the Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) showed the functional groups distinctive of the glucose.

ABSTRACT The study analyzes the association between self-destructive indirect behaviors and social anomie in a sample of 509 fourth grade high school students from Lima. A data sheet, the Kelley et al. (1985) Self-destructive behaviors Scale adapted to Spanish language by Ponce (2007) and the Li et al. (1999) Anomie Scale validated by Vera et al. (2013) were applied. The study found direct and significant association between both variables in the total sample (in cases with and without domestic violence), with moderate effect. In cases without domestic violence, discontent is associated with all self-destructive behaviors’ dimensions, followed by distrust associated to four of them. In teenagers who are victims of domestic violence, discontent is associated with lack of planning and anticipation and neglecting their duties and distrust is associated with neglecting their duties. Finally, in accordance with the results from multivariate logistic regression analyses, the only dimension of social anomie statistically significant (p<.05) to predict self-destructive behaviors is discontent.

RESUMEN El estudio analiza la asociación entre las conductas autodestructivas indirectas y la anomia social en una muestra de 509 escolares de cuarto de secundaria de instituciones educativas de Lima. Se empleó una ficha de datos, la escala de conductas autodestructivas de Kelley et al. (1985) adaptada al español por Ponce (2007) y la escala de anomia social de Li et al. (1999) validada por Vera et al (2013). Se halló asociación directa y significativa entre ambas variables en la muestra total (con y sin violencia familiar), con tamaño del efecto moderado. Cuando no existe violencia, el descontento se asocia con todas las dimensiones de las conductas autodestructivas, seguido de la desconfianza asociada con cuatro de ellas; en adolescentes con violencia, el descontento se asocia con falta de planeación, de anticipación y descuido de deberes y la desconfianza con descuido de deberes. Finalmente, de acuerdo con los resultados de la regresión logística, a nivel multivariado, la única dimensión de la anomia social que resulta estadísticamente significativa (p<.05) en la predicción de las conductas autodestructivas es descontento.

RESUMEN Las TIC en la educación tienen un abanico de posibilidades pedagógicas y hoy con la presencia de la pandemia del COVID19 ha marcado un antes y un después para la humanidad. La educación universitaria no es ajena a estos cambios, surgiendo la necesidad adaptarse a las tecnologías educativas acompañadas de estrategias didácticas y pedagógicas para alcanzar aprendizajes significativos y fortalecer complementariamente las clases presenciales. Esto lleva a presentar esta revisión científica sobre el uso de las TIC en la educación. Se han encontrado diferentes líneas de investigación como el computador y el entorno digital, el aprendizaje y la educación, las competencias digitales, el COVID19 y su influencia en la educación. Se realiza el análisis de estas líneas de investigación para orientar nuevos trabajos sobre la utilización de las TIC en el ámbito educativo y más en estos tiempos de pandemia que contribuyan a la mejora de procesos de enseñanza aprendizaje.

ABSTRACT ICTs in education have a range of pedagogical possibilities and today, with the presence of the COVID19 pandemic, it has marked a before and after for humanity. University education is not alien to these changes, emerging the need to adapt to educational technologies accompanied by didactic and pedagogical strategies to achieve meaningful learning and complement face-to-face classes. This leads to present this scientific review on the use of ICT in education. Different lines of research have been found such as the computer and the digital environment, learning and education, digital skills, COVID19 and its influence on education. The analysis of these lines of research is carried out to guide new works on the use of ICT in the educational field and more in these times of pandemic that contribute to the improvement of teaching-learning processes.

Introduction: Sphincter-sparing surgeries result in the development of a defecatory dysfunction with different degrees, which is known as low anterior resection syndrome (LARS) and is measured with the LARS Score questionnaire. Objective: To determine the association of the EuroQol-5 questionnaire with the different degrees of LARS Score. Materials and Method: Crosssectional study, applying the LARS Score and EuroQol-5 questionnaire to patients operated with low and middle rectal cancer, during the period 2004-2017. Demographic analysis and type of surgery are performed. Different statistical tests are used to determine associations between variables, considering a significant p value < 0.05. Results: 54 patients were surveyed, 62.16% men, mean age 58.44 years, 37.03% presented Mayor-LARS. The average quality of life indices for Non-LARS patients is 0.75, for Minor-LARS is 0.69 and for Mayor-LARS is 0.61, the difference between indices presents a p value = 0.246. 46.3% present problems in habitual activities. LARS Mayor presents an Odd-Ratio of 3.8 and 4.7 for pain/discomfort and anguish/depression respectively. 70% of patients with LARS Mayor presented SMT and 45% corresponded to those under 65 years of age. Discussion: There is no statistically significant difference between the quality of life indices according to the LARS Score. Mayor-LARS is more likely to develop some degree of Pain/Discomfort and anguish/depression. The percentage of Mayor-LARS is according to what has been published and the TME is one of the factors with the greatest impact on the development of LARS. Conclusion: The LARS Score is non-significantly related to the quality of life index provided by the EuroQol-5D questionnaire, and there is a tendency to decrease quality of life as the LARS worsens.

Resumen Introducción: Las cirugías con preservación de esfínter tienen como consecuencia el desarrollo de una disfunción defecatoria con diferentes grados, la cual es conocida como síndrome de resección anterior baja (LARS) y es medida con el cuestionario LARS Score. Objetivo: Determinar la asociación del cuestionario EuroQol-5 (calidad de vida) con los diferentes grados de LARS Score. Materiales y Método: Estudio de tipo transversal, aplicando el cuestionario LARS Score y EuroQol-5 a pacientes operados por cáncer de recto medio y bajo, durante el periodo 2004-2017. Se realiza análisis demográfico y del tipo de cirugía. Para determinar asociaciones entre variables se utilizan diferentes pruebas estadísticas, considerando significativo un valor de p < 0,05. Resultados: Se encuestó a 54 pacientes, 62,16% hombres, promedio de edad 58,44 años, el 37,03% presentó LARS Mayor. Los índices promedio de calidad de vida para pacientes No LARS es 0,75, para LARS Menor es 0,69 y para LARS Mayor es 0,61, la diferencia entre índices presenta un valor p = 0,246. 46,3% presenta problemas en actividades habituales. LARS Mayor presenta un Odd-Ratio de 3,8 y 4,7 para dolor/malestar y angustia/depresión respectivamente. 70% de los pacientes con LARS Mayor presentaron resección total del mesorrecto (TME) y el 45% corresponde a menores de 65 años. Discusión: No existe diferencia estadísticamente significativa entre los índices de calidad de vida según LARS Score. LARS Mayor tiene mayor posibilidad de desarrollar algún grado de dolor/malestar y angustia/depresión. El porcentaje de LARS Mayor es acorde a lo publicado y la TME es uno de los factores de mayor impacto en el desarrollo de LARS. Conclusiones: El LARS Score se relaciona de manera no significativa con el índice de calidad de vida entregado por el cuestionario EuroQol-5D, existiendo una tendencia a disminuir la calidad de vida a medida que empeora el LARS.

Fusarium wilt, caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense (Foc), poses a major threat to banana production globally. A variant of Foc that originated in Southeast Asia, called tropical race 4 (TR4), was detected on a Cavendish banana export plantation (Metocheria) in northern Mozambique in 2013. Foc TR4 was rapidly disseminated on the farm, and affected approximately half a million plants within 3 years. The fungus was also detected on a second commercial property approximately 200 km away (Lurio farm) a year later, and on a small-grower's property near Metocheria farm in 2015. Surveys in Mozambique showed that non-Cavendish banana varieties were only affected by Foc race 1 and race 2 strains. The testing of Cavendish banana somaclones in northern Mozambique revealed that GCTCV-119 was most resistant to Foc TR4, but that GCTCV-218 produced better bunches. The occurrence of Foc TR4 in northern Mozambique poses a potential threat to food security on the African continent, where banana is considered a staple food and source of income to millions of people. Cavendish somaclones can be used, in combination with integrated disease management practices, to replace susceptible Cavendish cultivars in southern Africa. The comprehensive testing of African cooking bananas for resistance to Foc TR4 is required, along with the improvement of biosecurity and preparedness of growers on the African continent.SIGNIFICANCE: • This paper presents the first official report of the invasive pest Foc TR4 in Africa. • The spread of Foc TR4 on Cavendish banana farms in Mozambique was documented. • Banana varieties that could replace susceptible Cavendish bananas were identified.

Background: Myocardial infarction with non-obstructive coronary artery disease (MINOCA) is common. Cardiac magnetic resonance (CMR) and intravascular imaging (IVI) may be useful for establishing its etiology. Aim: To describe a population with MINOCA and its multi-image assessment using IVI or CMR. Material and Methods: Review of medical records, imaging and functional studies of patients with MINOCA treated in three different clinical centers between 2015 and 2019. Results: Twenty-eight patients with MINOCA and IVI were included. Seventy eight percent were women, 46% had hypertension, 32% smoked and 32% had dyslipidemia. At wall motion assessment, 46% presented apical ballooning pattern. In 36% of patients IVI identified lesions that explained the cause of MINOCA, namely plaque disruption (PD) in 18%, spontaneous coronary dissection in 11% and a thrombus without PD in 7%. Forty-six percent of patients had uncomplicated atherosclerotic plaques, and 36% had no pathological findings. CMR was performed in 50% of patients, identifying in all a diagnostic pattern. In nine cases it was compatible with stress cardiomyopathy, three cases had a myocarditis and two cases had transmural infarctions. PD and transmural late gadolinium enhancement were observed in 23% of patients with apical ballooning. Patients with a pattern of myocarditis did not have acute pathological findings at IVI. After a mean follow-up of 16.4±11.4 months, 3 patients with PD died. Conclusions: Among patients with MINOCA, there was a predominance of female gender with low cardiovascular risk factor load. The multi-image assessment allowed greater precision for etiological diagnosis of MINOCA. Apical ballooning was not pathognomonic for stress cardiomyopathy. PD was associated with mortality.

El artículo se propone problematizar el proceso de transformaciones del trabajo contemporáneo en Chile. Se describen tres experiencias desde las clínicas del trabajo (educacional, psicosocial y socioanálisis) en diferentes escenarios laborales. A su vez, se realiza una reflexión sobre la pertinencia de la clínica del trabajo como forma de intervención para contribuir a la comprensión de los procesos subjetivos de los trabajadores, en su dimensión individual, grupal y política.

O artigo propõe-se problematizar o processo de transformações do trabalho contemporâneo no Chile. Três experiências são descritas a partir de estudos desenvolvidas na perspetiva das clínicas do trabalho (educacional, psicossocial e socioanálise) em diferentes cenários de trabalho. A seguir, faz-se uma reflexão sobre a relevância da abordagem da clínica do trabalho como forma de intervenção que contribui para a compreensão dos processos subjetivos dos trabalhadores, nas suas dimensões individual, grupal e política.

L'article propose une problématisation du processus de transformation du travail contemporain au Chili. Trois expériences sont décrites au départ d'études menées selon la perspective des cliniques de travail (éducatives, psychosociales et socio-analytiques) dans différents scénarios de travail. Une réflexion est menée ensuite à propos de la pertinence de l'approche de la clinique du travail, définie en tant que mode d'intervention contribuant à la compréhension des processus subjectifs des travailleurs, dans leur dimension individuelle, de groupe et politique.

The paper aims at problematizing the process of contemporary work transformations in Chile. Three experiences are described from a clinical point of view (pedagogical, psychosocial and socio-analytical) in different work scenarios. Then, it reflects on the relevance of the clinical approach as a form of intervention, which contributes to the understanding of the workers' subjective processes, in their individual, group and political dimensions.

Abstract Spontaneous coronary artery dissection (SCAD) is characterized by tear of the inner layer in the coronary artery, creating a false lumen between the inner and central layer. Its infrequent incidence often leads to delay in diagnosis posing challenges in management. There are currently no guidelines for the treatment of this condition. We describe an adult patient who presented with multiple episodes of ventricular fibrillation, in whom cardiac catheterization showed SCAD, treated by off-pump coronary artery bypass.

The orientation of pterin-6-carboxylic acid on gold nanopillars was investigated by surface enhanced Raman spectroscopy and density functional theory methods. The experimentally vibrations from pterin-6-COOH free and attached to the Au surface display vibration features indicating chemical interaction of the pterin with the metal surface. The spectral feature evidenced that the pterin would adsorb on gold surface with a "lying down" configuration through the high intensity vibration of NH scissoring and rocking OH modes. The orientation study of pterins on gold nanopillars presented herein is believed to lead to new applications in biosensing field for detecting pterins of physiological importance.

We present a study of the structural validity of the questionnaire proposed by Philip R. Harris (1995; Spanish translation by the Centro de Estudios Ramón Areces, 2001) aimed to assess the effectiveness of the individual behavior of people working in a team. The instrument was applied to a sample of 771 employees from different teams existing in several organizations dedicated to the care of dependent adults. The completion of the exploratory factor analysis revealed a three-dimensional factor structure that explained 63.2% of the total common variance. The three factors identified in the analysis were labelled Communication skills, Emotional expression and Acceptance. Philip R. Harris proposed an interpretation of the test responses for each one of the questionnaire items separately; however, our results support obtaining of scores on the three factors extracted, which represent relevant dimensions in the study of the skills that the components of an effective team should possess.

Se presenta un estudio de la validez estructural del cuestionario planteado por Philip R. Harris (1995; traducción al castellano realizada por el Centro de Estudios Ramón Areces, 2001) orientado a evaluar la eficacia del comportamiento individual de las personas que trabajan en un equipo. El instrumento se aplicó a una muestra compuesta por 771 empleados pertenecientes a distintos equipos de trabajo existentes en diversas organizaciones dedicadas a la atención a la dependencia. La realización del análisis factorial exploratorio reveló una estructura factorial de tres dimensiones, etiquetadas como "habilidades comunicativas", "expresión emocional" y "aceptación", que explicaba el 63.2% de la varianza común total. El autor del cuestionario propuso una interpretación de los datos basada en las respuestas dadas a cada uno de los ítems del cuestionario por separado. Sin embargo, los resultados obtenidos en este estudio respaldan la obtención de puntuaciones en los tres factores extraídos, los cuales representan dimensiones relevantes en el estudio de las habilidades que los componentes de un equipo eficaces deben poseer.

Abstract: Rosenberg's self-esteem scale has been extensively used in all areas of psychology to assess global self-esteem (Rosenberg, 1965, 1979). Its construct validity, and specifically its factor structure, has almost from the beginning been under debate. More than four decades after its creation the cumulated evidence points that the scale measures a single trait (self-esteem) but confounded by a method factor associated to negatively worded items. The aim of the study is to examine the measurement invariance of the RSES by gender and test potential gender differences at the latent (trait and method) variable level, while controlling for method effects, in a sample of Spanish students. A series of completely a priori structural models were specified, with a standard invariance routine implemented for male and female samples. The results lead to several conclusions. Conclusions: a) the scale seem gender invariant for both trait and method factors; b) there were small but significant differences between males and females in self-esteem, differences that favored male respondents; and c) there were statistically non-significant differences between men and women in the method factor's latent means.

Resumen: La Escala de Autoestima de Rosenberg (EAR) ha sido utilizada extensamente en todas las áreas de la Psicología para evaluar la autoestima (Rosenberg, 1965, 1979). Su validez de constructo, y particularmente su estructura factorial, ha estado en debate casi desde que fue construida. Más de cuatro décadas después de su creación, la evidencia acumulada señala que la escala evalúa un solo rasgo (autoestima), aunque se confunde con un método factorial asociado de manera negative con reactivos verbales. El objetivo de este estudio fue evaluar la estabilidad de la medición de la EAR entre sexos y poner a prueba potenciales diferencias entre los mismos en un nivel latente de la variable (rasgo y estado), controlando efectos de método, en una muestra de estudiantes españoles. Se especificaron una serie de modelos estructurales a priori, con rutinas implementadas de invarianza estándar para muestras de hombres y mujeres. Los resultados llevan a diferentes conclusiones: a) La escala parece ser invariable ante el sexo tanto para factores de rasgo como de estado; b) existieron diferencias pequeñas, pero significativas, entre hombres y mujeres en autoestima, favoreciendo ligeramente a los hombres; y, c) no existieron diferencias estadísticamente significativas entre hombres y mujeres en las medias de la variable latente del factor.

In the last years, the number of patients presenting jaw osteonecrosis associated with the use of bisphosphonates (BIONJ) has increased. This is due to increased consumption of bisphosphonates, which are associated with the treatment of carcinomas with bone metastases, multiple myeloma, osteoporosis, osteopenia and metabolic diseases such as Paget´s disease. The aim of this review is to analyze the number of cases of patients who developed jaws osteonecrosis-associated with the use of bisphosphonates, published from June 2006 to April 2010. In this review, we referred to the databases Pubmed-Medline, Scielo and Spanish Medical Index, including limits on the search to collect BIONJ cases published from 2006 up to now. The selected papers presented cases in which the patients who received bisphosphonates developed BIONJ. We found 491 cases of BIONJ in total, of which 49.3% correspond to women, 32% to men and 18.7%, did not establish gender. Most of these cases occurred in the mandible and associated particularly with zoledronic acid. In the coming years it is expected that the number of patients who develop this complication increase, particularly in women, who are more and more prescribed this medication for the osteoporosis treatment.

En los últimos años, el número de pacientes que presenta osteonecrosis maxilar asociada al uso de bifosfonatos (BIONJ) se ha incrementado. Esto es debido al aumento en el consumo de bifosfonatos, los cuales se asocian al tratamiento de carcinomas con metástasis óseas, mieloma múltiple, osteoporosis, osteopenia y enfermedades metabólicas como la enfermedad de Paget. Objetivo: Analizar el número de casos de pacientes que han desarrollado osteonecrosis de maxilares asociado al uso de bifosfonatos, publicados desde Junio del año 2006 hasta Abril 2010. Método: En esta revisión, se consultaron las bases de datos Pubmed-Medline, Scielo e Índice Médico Español, incluyendo límites en la búsqueda, para recopilar los casos de BIONJ que se hayan publicado desde el año 2006 hasta la actualidad. Los artículos seleccionados presentaban casos, en los cuales los pacientes que recibían bifosfonatos desarrollaban BIONJ. Resultados: Se encontraron 491 casos de BIONJ en total, de ellos 49,3% eran mujeres, 32% hombres y 18,7% no se establecía el género. La mayoría de estos casos se presentaron en la mandíbula y asociados particularmente al ácido zolendrónico. Conclusiones: En los próximos años se espera que el número de pacientes que desarrollen esta complicación vaya en aumento, en particular en mujeres, a las cuales se les indica cada vez más esta medicación para el tratamiento de la osteoporosis.

Elymus scabrífolius is a perennial South American wheatgrass, considered as a potential forage resource for environments with soil limitations. The aims of this work were to analyze the genetic variation for agronomic traits and determine patterns of phenotypic variation for 17 accessions and one commercial cultivar, by analysis of variance and multivariate analysis. All traits showed significant statistical differences between materials. In the cluster analysis, the commercial cultivar clearly differentiated from the other accessions, which formed t\vo clusters based in their geographical origin. The results of Principal Component Analysis were consisten! with those observed in the dendrogram. The results indicated the existence of considerable genetic variation among the analyzed materials and suggested the importance of geographical origin in both, the distribution of this variation as well as searching of nevv genetic variation for this species.

Elymus scabrífolius es una gramínea perenne nativa de Sudamérica, considerada como potencial recurso forrajero para suelos con limitantes edáficas. Los objetivos de este trabajo fueron analizar la variación genética existente para caracteres agronómicos y determinar patrones de variación fenotípica para 17 accesiones y un cultivar comercial, mediante análisis de varianza y técnicas multivariadas. Los materiales presentaron diferencias significativas para todas las variables agronómicas analizadas. En el análisis de agrupamiento, el cultivar comercial se diferenció claramente de las otras accesiones, las cuales se agruparon formando dos conglomerados según su región de procedencia. Los resultados del Análisis de Componentes Principales fueron concordantes con lo observado en el dendrograma. Los resultados indicaron la existencia de considerable variación genética entre los materiales analizados y sugieren la importancia del origen geográfico tanto en la distribución de dicha variación, como así también en la búsqueda de nueva variación genética para esta especie.

The search for forage legumes to improve animal production is a priority in the centre-north of Argentina. This study aims to determine the variability for morphological traits related with the early vegetative growth in populations of two native forage legumes, Desmanthus virgatus y D. paspalaceus and analyze their field establishment in two environments. Variation was found in all of the traits analyzed and useful populations were identified with a view to their incorporation into breeding programs. Big fractions of the total phenotypic variation for almost all traits was due to interpopulational and intrapopulational variation. Correlations among characters indicate that a simultaneous improvement is possible by means of aerial biomass without compromising reserve accumulation in roots. All populations had low field establishment rate on the two locations used. The causes of this problem are discussed in this paper.

En la actualidad, una prioridad para mejorar la producción ganadera en el centro-norte de Argentina es la búsqueda de leguminosas forrajeras adaptadas a la región.Este trabajo tuvo como objetivos: a) analizar la variabilidad de caracteres morfológicos relacionados con el crecimiento inicial en poblaciones de dos especies de forrajeras nativas, Desmanthus virgatus y D. paspalaceus, y b) evaluar la implantación a campo en dos ambientes. Se encontró variación en los caracteres relacionados con el crecimiento inicial en ambas especies se identificaron poblaciones promisorias para incorporar en programas de mejoramiento. Una parte importante de la variación encontrada corresponde a variaciones interpoblacionales e intrapoblacionales. Las correlaciones entre caracteres indican que es posible mejorar simultáneamente por producción de biomasa aérea sin comprometer la acumulación de reservas en la raíz. Todas las poblaciones mostraron un bajo establecimiento a campo en los dos ambientes analizados. Se discuten las causas probables de dicho comportamiento.