Cartografía de QTL asociados a la tolerancia a estrés hídrico en frijol común (Phaseolus vulgaris L.)

Phaseolus vulgaris L. (frijol común o judía) es una leguminosa de gran demanda para la nutrición humana y un producto agrícola muy importante. Sin embargo, la producción de frijol se ve limitada por presiones ambientales como la sequía. En México, el 85% de la cosecha de frijol se produce en la temporada de primavera-verano, principalmente en las regiones del altiplano semiárido con una precipitación anual entre 250 y 400 mm. A pesar del implemento de tecnología en el campo, los factores naturales impiden al agricultor llegar a los rendimientos deseados. El Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP), como instituto de investigación gubernamental en México, tiene como objetivo la mejora de cultivos estratégicos, uno de ellos, P. vulgaris. Los estudios en relación a la sequía se enfocan especialmente en la selección de genotipos tolerantes, los cuales son sometidos en condiciones de estrés y monitoreando parámetros como el rendimiento y peso de semilla, además de algunos indicadores tales como índice de cosecha. El resultado de estos trabajos ha sido la obtención de variedades con mayor tolerancia a la sequía, tales como Pinto Villa y Pinto Saltillo. En los últimos años se ha avanzado notablemente en el conocimiento de las bases moleculares en las respuestas de las plantas al estrés. De acuerdo a diversos estudios se ha demostrado que las plantas bajo estrés por sequía experimentan cambios en la expresión de genes involucrados en la señalización, regulación de la transcripción y la traducción, transporte de agua y la función directa en la protección celular. También se ha observado que el déficit de agua es causado por las temperaturas extremas y la alta concentración de sales, por lo que al nivel molecular, las respuestas al estrés tienen puntos de especificidad y puntos de entrecruzamiento. La sequía puede generar estreses secundarios, tales como el nutricional, oxidativo y osmótico. Sin embargo, es necesario identificar y caracterizar muchos de los componentes involucrados en las respuestas al déficit hídrico, la caracterización de estos genes permitirá tener una mejor comprensión de los mecanismos bioquímicos y fisiológicos involucrados en la tolerancia al estrés. Actualmente, con el apoyo de la biología molecular se han identificado algunos genes que otorgan ventajas para la adaptación a ambientes desfavorables. Por lo que el objetivo del presente trabajo es identificar marcadores genéticos asociados a rasgos fenotípicos con énfasis a la tolerancia a estrés hídrico en P. vulgaris. Una vez establecidos los marcadores asociados al estrés hídrico, es factible considerar su uso para la selección asistida por marcadores en líneas o variedades de frijol de interés para los mejoradores. Se evaluaron 282 familias F3:5 derivadas de la cruza entre los cultivares Pinto Villa y Pinto Saltillo. Las familias se sembraron bajo un diseño simple de látice 17x17, el experimento se llevo acabo en el ciclo primavera-verano del 2010 y 2011, y otoñoinvierno de 2010 en el Campo Experimental Bajío del INIFAP con dos repeticiones para cada tratamiento de humedad (riego completo y sequía terminal). En todos los genotipos se realizó el fenotipado (variables fenotípicas) y el genotipado a través de marcadores moleculares. Los análisis estadísticos se basaron en el análisis de componentes principales (Eigen Analysis Selection Index Method, ESIM), la asociación entre marcadores SNP y el fenotipado (paquete SNPassoc para R) y el análisis de varianza (ANOVA). Los valores ESIM mostraron que las variables de Rendimiento, Días a floración, Días a madurez fisiológica e Índice de cosecha fueron sobresalientes en sequía terminal, por lo que se sugieren tomarse en consideración para los estudios de sequía en P. vulgaris como monitores de evaluación a la resistencia. Se identificaron nueve familias sobresalieron por sus valores ESIM (PV/PS6, 22, 131, 137, 149, 154, 201, 236 y 273), además de presentar valores superiores para el rendimiento en comparación con los parentales. Estos genotipos son candidatos interesantes para realizar estudios de identificación de loci asociados con la respuesta al estrés, y como potenciales parentales en el desarrollo de nuevas variedades de frijol. En los análisis de asociación SNPassoc se identificaron 83 SNPs significativos (p<0,0003) asociados a los rasgos fenotípicos, obteniendo un total de 222 asociaciones, de las cuales predomina el modelo genético de codominancia para las variables Días a floración, Periodo reproductivo y Biomasa total. Treinta y siete SNPs se identificaron a diferentes funciones biológicas a través del análisis de anotación funcional, de los cuales 12 SNPs (9, 18, 28, 39, 61, 69, 80, 106, 115, 128, 136 y 142) sobresalen por su asociación al fenotipado, y cuya anotación funcional indica que se encuentran en genes relacionados a la tolerancia a la sequía, tales como la actividad kinasa, actividad metabólica del almidón, carbohidratos y prolina, respuesta al estrés oxidativo, así como en los genes LEA y posibles factores de transcripción. En el caso de los análisis ANOVA, se identificaron 72 asociaciones entre los SNPs y las variables fenotípicas (F< 3,94E-04). Las 72 asociaciones corresponden a 30 SNPs y 7 variables fenotípicas, de las que predomina Peso de 100 semillas y Periodo reproductivo. Para los rasgos de Rendimiento, Índice de cosecha y Días a madurez fisiológica se presentaron asociaciones con seis SNPs (17, 34, 37, 50, 93 y 107), de los cuales, a los SNP37 y SNP107 fueron identificados a la anotación biológica de protein binding. Por otro lado, los SNP106 y SNP128 asociados al Periodo reproductivo, son genes con actividad kinasa y actividad metabólica del almidón, respectivamente. Para los marcadores tipo AFLP, se identificaron 271 asociaciones (F<2,34E-04). Las asociaciones corresponden a 86 AFLPs con todas las variables fenotípicas evaluadas, de las que predomina peso de 100 semillas, Días a floración y Periodo reproductivo. Debido a que los en los AFLPs no es posible determinar su anotación biológica, se proponen como marcadores potenciales relacionados a la resistencia a la sequía en frijol. Los AFLPs candidatos requieren más estudios tales como la secuenciación de los alelos respectivos, así como la identificación de éstas secuencias en el genoma de referencia y su anotación biológica, entre otros análisis, de esta manera podríamos establecer aquellos marcadores candidatos a la validación para la selección asistida. El presente trabajo propone tanto genotipos como marcadores genéticos, que deben ser validados para ser utilizados en el programa de mejoramiento de P. vulgaris, con el objetivo de desarrollar nuevas líneas o variedades tolerantes a la sequía. ABSTRACT Phaseolus vulgaris L. (common bean or judia) is a legume of great demand for human consumption and an important agricultural product. However, the common bean production is limited by environmental stresses, such as drought. In Mexico, 85% of the common bean crop is produced in the spring-summer season mainly in semiarid highland regions with a rainfall between 250 and 400 mm per year. In spite of the improvement of crop technology, the natural factors hamper getting an optimal yield. The National Institute for Forestry, Agriculture and Livestock (INIFAP) is a government research institute from Mexico, whose main objective is the genetic breeding of strategic crops, like P. vulgaris L. The drought tolerance studies particularly focus on the selection of bean tolerant genotypes, which are subjected to stress conditions, by means of monitoring parameters such as yield and seed weight, plus some agronomic indicators such as harvest index. The results of these works have led to obtain cultivars with higher drought tolerance such as Pinto Villa and Pinto Saltillo. Significant achievements have been recently made in understanding the molecular basis of stress plant responses. Several studies have shown that plants under drought stress present changes in gene expression related to cell signalling, transcriptional and translational regulation, water transport and cell protection. In addition, it has been observed that the extreme temperatures and high salt concentrations can cause a water deficiency so, at the molecular level, stress responses have specific and crossover points. The drought can cause secondary stresses, such as nutritional, oxidative and osmotic stress. It is required the identification of more components involved in the response to water deficit, the characterization of these genes will allow a better understanding of the biochemical and physiological mechanisms involved in stress tolerance. Currently, with the support of molecular biology techniques, some genes that confer an advantage for the crop adaptation to unfavourable environments have been identified. The objective of this study is to identify genetic markers associated with phenotypic traits with emphasis on water stress tolerance in P. vulgaris. The establishment of molecular markers linked to drought tolerance would make possible their use for marker-assisted selection in bean breeding programs. Two hundred and eighty two F3:5 families derived from a cross between the drought resistant cultivars Pinto Villa and Pinto Saltillo were evaluated. The families were sowed under a 17x17 simple lattice design. The experiment was conducted between spring-summer seasons in 2010 and 2011, and autumn-winter seasons in 2010 at the Bajio Experimental Station of INIFAP with two treatments (full irrigation and terminal drought). All families were phenotyped and genotyped using molecular markers. Statistical analysis was based on principal component analysis (Eigen Analysis Selection Index Method, ESIM), association analysis between SNP markers and phenotype (SNPassoc package R) and analysis of variance (ANOVA). The ESIM values showed that seed yield, days to flowering, days to physiological maturity and harvest index were outstanding traits in terminal drought treatment, so they could be considered as suitable parameters for drought-tolerance evaluation in P. vulgaris. Nine outstanding families for the ESIM values were identified (PV/PS6, 22, 131, 137, 149, 154, 201, 236 and 273), in addition, these families showed higher values for seed yield compared to the parental cultivars. These families are promising candidates for studies focused on the identification of loci associated to the stress response, and as potential parental cultivars for the development of new varieties of common bean. In the SNPassoc analysis, 83 SNPs were found significantly associated (p<0.0003) with phenotypic traits, obtaining a total of 222 associations, most of which involved the traits days to flowering, reproductive period and total biomass under a codominant genetic model. The functional annotation analysis showed 37 SNPs with different biological functions, 12 of them (9, 18, 28, 39, 61, 69, 80, 106, 115, 128, 136 and 142) stand out by their association to phenotype. The functional annotation suggested a connection with genes related to drought tolerance, such as kinase activity, starch, carbohydrates and proline metabolic processes, responses to oxidative stress, as well as LEA genes and putative transcription factors. In the ANOVA analysis, 72 associations between SNPs and phenotypic traits (F<3.94E- 04) were identified. All of these associations corresponded to 30 SNPs markers and seven phenotypic traits. Weight of 100 seeds and reproductive period were the traits with more associations. Seed yield, harvest index and days to physiological maturity were associated to six SNPs (17, 34, 37, 50, 93 and 107), the SNP37 and SNP107 were identified as located in protein binding genes. The SNP106 and SNP128 were associated with the reproductive period and belonged to genes with kinase activity and genes related to starch metabolic process, respectively. In the case of AFLP markers, 271 associations (F<2.34E-04) were identified. The associations involved 86 AFLPs and all phenotypic traits, being the most frequently associated weight of 100 seeds, days to flowering and reproductive period. Even though it is not possible to perform a functional annotation for AFLP markers, they are proposed as potential markers related to drought resistance in common bean. AFLPs candidates require additional studies such as the sequencing of the respective alleles, identification of these sequences in the reference genome and gene annotation, before their use in marker assisted selection. This work, although requires further validation, proposes both genotypes and genetic markers that could be used in breeding programs of P. vulgaris in order to develop new lines or cultivars with enhanced drought-tolerance.

Volcanic setting of the Bajo de la Alumbrera porphyry Cu-Au deposit, Farallon Negro Volcanics, Northwest Argentina

The late Miocene Farallon Negro volcanics, comprising basaltic to rhyodacitic volcano-sedimentary rocks, host the Bajo de la Alumbrera porphyry copper-gold deposit in northwest Argentina. Early studies of the geology of the district have underpinned the general model for porphyry ore deposits where hydrothermal alteration and mineralization develop in and around porphyritic intrusions emplaced at shallow depths (2.5-3.5 km) into stratovolcanic assemblages. The Farallon Negro succession is dominated by thick sequences of volcano-sedimentary breccias, with lavas forming a minor component volumetrically. These volcaniclastic rocks conformably overlie crystalline basement-derived sedimentary rocks deposited in a developing foreland basin southeast of the Puna-Altiplano plateau. Within the Farallon Negro volcanics, volcanogenic accumulations evolved from early mafic to intermediate and silicic compositions. The younger and more silicic rocks are demonstrably coeval and comagmatic with the earliest group of mineralized porphyritic intrusions at Bajo de la Alumbrera. Our analysis of the volcanic stratigraphy and facies architecture of the Farallon Negro volcanics indicates that volcanic eruptions evolved from effusive to mixed effusive and explosive styles, as magma compositions changed to more intermediate and silicic compositions. Air early phase of mafic to intermediate voleanism was characterized by small synsedimentary intrusions with peperitic contacts, and lesser lava units scattered widely throughout the district, and interbedded with thick and extensive successions of coarse-grained sedimentary breccias. These sedimentary breccias formed from numerous debris- and hyperconcentrated flow events. A later phase of silicic volcanism included both effusive eruptions, forming several areally restricted lavas, and explosive eruptions, producing more widely dispersed (up to 5 kin) tuff units, some tip to 30-m thickness in proximal sections. Four key features of the volcanic stratigraphy suggest that the Farallon Negro volcanics need not simply record the construction of a large steep-sided polygenetic stratovolcano: (1) sheetlike, laterally continuous debris-flow and other coarse-grained sedimentary deposits are dominant, particularly in the lower sections; (2) mafic-intermediate composition lavas are volumetrically minor; (3) peperites are present throughout the sequence; and (4) fine-grained lacustrine sandstone-siltstone sequences occur in areas previously thought to be proximal to the summit region of the stratovolcano. Instead, the nature, distribution, and geometry of volcanic and volcaniclastic facies suggest that volcanism occurred as a relatively low relief, multiple-vent volcanic complex at the eastern edge of a broad, > 200-km-wide late Miocene volcanic belt and oil ail active foreland sedimentary basin to the Puna-Altiplano. Volcanism that occurred synchronously with the earliest stages of porphyry-related mineralization at Bajo de la Alumbrera apparently developed in an alluvial to ring plain setting that was distal to larger volcanic edifices.

Die Gletscher der bolivianischen Anden, Verbreitung von Gletschern und neuzeitlichen Moränen in der Cordillera Apolobamba Cololo Region (Ostkordillere)

The uniform triangulation of the whole glacierized area of the Eastern Cordillera of Bolivia provided the first comparable geometrie basis for an accurate photogrammetric height evaluation of glaciers in the mountain range from the far south up to the Peruvian border. A total of 1775 glaciers, larger than 0.1 ha, were recorded in 16 mountain ranges ofthe East- ern Cordillera. Snow lines in the outer tropics can now be analysed with an accuracy of European standards. In spite of the widemeshed network of meteorological stations this allows a more pre- eise climatic differentiation to be made, particularly at high altitude sites. The methods and results of the analysis are described. Because of these results it becomes necessary to revise and refine previous concepts of the spatial distribution of climatic phenomena. Characteristics of glaciers in the Bolivian Cordillera obviously depend on the NE to SW decline in precipitation. The snow lines which are found at an altitude of 4500 m on the north- eastern slope directed towards the Yungas climb up to 5200 m on the lee slope towards the Alti- plano. The N to S increase in snowline elevation is not as significant as expected. With some res- ervation a 100 m fall in the snowline elevation in the Bolivian Cordillera can be explained by an increase in precipitation of about 50 mm.

Haematological and biochemical blood study in baby alpaca with diarrhoea

The aim of this study was to determine the haematological value and biochemical blood in baby alpacas with enteric disorder. A total of 30 blood and serum samples were collected from alpacas of 1 month old with diarrhoea and 5 blood samples of clinically healthy baby alpacas (controls). The animals were from communities in the central Andes from Peru. About haematology were determined haematocrit, haemoglobin concentration, red blood count and white blood count that were not significantly different between control animals and animals with diarrhoea. Moreover, biochemical blood parameters as total protein, albumin and calcium decrease significantly (p<0.05). We conclude that our results could be considered as factors in the mortality of baby alpaca by infectious diarrhoea.

Palaeo-geoecological significance of Pleistocene trees in the Lluta Valley, Atacama Desert

In the Lluta Valley, northern Chile, climate is hyperarid and vegetation is restricted to the valley floors and lowermost footslopes. Fossil tree trunks and leaves of predominantly Escallonia angustifolia, however, are abundant up to ∼15 m above the present valley floor, where they are intercalated with slope deposits, reflecting higher water levels in the past. A total of 17 samples have been radiocarbon dated, yielding ages between 38 and 15k cal a BP. The youngest ages of 15.4k cal a BP are interpreted as reflecting the beginning of river incision and lowering of the valley floor, impeding the further growth of trees at higher parts of the slopes. The most plausible scenario for this observation is intensified river incision after 15.4k cal a BP due to increased stream power and runoff from the Río Lluta headwaters in the Western Cordillera and Altiplano corresponding to the highstand of the Tauca and Central Andean Pluvial Event (CAPE) wet phase.

Las cuestiones de género en la evaluación de proyectos rurales

Introducción “El Banco Comunal es manejado por las mujeres (…), les da los préstamos en forma rápida, sin mucha papelería, les ayuda a mejorar sus ‘haceres’; por el banco han aprendido muchas cosas (…) y los resultados son buenos también para nosotros los hombres y para toda la familia (…)”, manifestaba el esposo de una socia de un Banco Comunal en el Altiplano Guatemalteco, en una reunión de Evaluación. Al escuchar esta expresión, las mujeres presentes comenzaran a reflexionar sobre los aspectos positivos y negativos de su proyecto y sobre lo que peste ha significado en sus vidas y en su trabajo.

El impacto del desarrollo del café en un territorio no cafetalero: Conformación del municipio de mozos de Colotenango en Guatemala, 1877-1947.

ResumenEste artículo analiza cómo un territorio mam en el marginal altiplano guatemalteco, Colotenango, se articuló en el siglo XIX con la economía liberal, como municipio de mozos para las fincas agroexportadoras de café ubicadas en la bocacosta. Siendo un territorio no apto para el cultivo del café, la política estatal de impulso de la economía vinculada a ese producto tuvo efectos devastadores para los municipios del altiplano indígena, como fue el caso de Colotenango. Especialmente, se explora el papel de la Municipalidad en el sistema agroexportador, sustrato de los permanentes conflictos jurisdiccionales que existen en la zona.AbstractThis article analyzes the way in which Colotenango, a mam territory in the impoverished Guatemalan highlands, became a part of the liberal economy in the nineteenth century by constituting a municipio de mozos for the coffee export plantations located in the coastal region. Since this land had traditionally been considered not apt for coffee-growing purposes, the governmental policy aimed at boosting the economy based on this product, had devastating effects on the municipalities of the indigenous highlands, such as the case of Colotenango. Particularly, this article delves into the role played by the Municipality in the agricultural export system, which became the essence of continuous jurisdictional conflicts in the region still present today.

El APRA, Haya de La Torre y la crisis del liberalismo guatemalteco en 1926-1929

ResumenEn julio de 1928 el líder del APRA visitó Guatemala. Durante poco más de un mes, Haya de la Torre dio conferencias, realizó una gira política por el altiplano occidental y en Quetzaltenango fundó el Comité Ejecutivo Centroamericano del APRA. La filiación política original de los simpatizantes de Haya de la Torre en Guatemala era el liberalismoAbstractWhen he visited Guatemala in July, 1928, the leader of APRA gave public lectures, went on a political tour of the western highlands, and in Quetzaltenango he founded the Central American Executive Committee of APRA. The political background of Haya de la Torre’s supporters in Guatemala was Liberalism.