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Festuca arundinacea Schreb., commonly known as tall fescue, is a major forage crop in temperate regions. Recently, a molecular analysis of different accessions of a world germplasm collection of tall fescue has demonstrated that it contains different species from the genus Festuca and allowed their rapid classification into the three major morphotypes (Continental, Mediterranean and Rhizomatous). In this study, we explored the genetic diversity of 161 accessions of Festuca species from 29 countries, including 28 accessions of INTA (Argentina), by analyzing 15 polymorphic SSR markers by capillary electrophoresis. These molecular markers allowed us to detect a total of 214 alleles. The number of alleles per locus varied between 5 and 24, and the values of polymorphic information content ranged from 0.627 to 0.840. In addition, the accessions analyzed by flow cytometry showed different ploidy levels (diploid, tetraploid, hexaploid and octaploid), placing in evidence that the world germplasm collection consisted of multiple species, as previously suggested. Interestingly, almost all accessions of INTA germplasm collection were true hexaploid tall fescue, belonging to two eco-geographic races (Continental and Mediterranean). Finally, the data presented revealed an ample genetic diversity of tall fescue showing the importance of preserving the INTA collection for future breeding programs.

Collection of Bromus catharticus Vahl was carried out in the Argentine humid and sub-humid central area. Sixty-eight natural populations are conserved for medium and long term in Pergamino Germplasm Bank and in IRB Germplasm Bank, and ten morphological and agronomic traits were evaluated in the field during two years. There was variability for the traits considered among the accessions. Those populations from the subhumid area showed differences in valuable attributes for breeding. Exploration of marginal areas for this species might be an effective way to add variability to this collection.Coletas de Bromus catharticus Vahl foram conduzidas nas areas úmidas e sub-úmidas centrais da Argentina. Sessenta e oito populações naturais foram mantidas por médio e longo períodos nos bancos de germoplasma Pergamino e IRB, e dez características morfológicas agronômicas foram avaliadas em campo durante dois anos. Foi observada variabilidade para as características entre os acessos. As populações da região sub-úmida mostraram diferenças para características importantes para o melhoramento. A exploração de áreas marginais para esta espécie pode ser um modo efetivo de adicionar variabilidade para esta coleção de germoplasma.

When breeding temperate forage species is investigated, some attributes such as herbage accumulation and seasonal growth patterns have to be considered. To modify some of these traits, knowledge of the detailed process might be useful. In order to evaluate seasonal growth of contrasting white clover populations an experiment was carried out. Treatments were five cultivars and three local populations collected in Argentina. Weekly measures were taken during each season to calculate leaf appearance and flower appearance rates, stolon growing rate and dry matter (DM) net accumulation. Different germplasm of this species have different mechanisms for DM accumulation. Leaf size, more than leaf appearance rate, was the variable with most differences among germplasm and mostly related to dry matter accumulation. During spring and summer, inflorescences production had important effects on growing stolon rate, and differences among germplasm were evident. Some local populations showed favourable attributes that could be useful for breeding.Quando o melhoramento de forrageiras de clima temperado é investigado, alguns atributos tais como acúmulo de forragem e padrões de crescimento sazonal devem ser considerados. Para a modificação de alguns desses caracteres, o conhecimento detalhado destes processos pode ser útil. No sentido de avaliar o crescimento sazonal de populações contrastantes de trevo branco, um experimento foi conduzido. Os tratamentos consistiram de cinco cultivares e três populações nativas coletadas na Argentina. Medições semanais foram realizadas durante cada estação do ano para cálculo das taxas de aparecimento de folhas e flores, taxa de crescimento de estolões e acúmulo de matéria seca. Germoplasmas distintos para essa espécie apresentam mecanismos distintos para acúmulo de matéria seca. A característica de tamanho de folha, mais do que a taxa de aparecimento de folha, foi a variável analisada que mostrou as maiores diferenças entre os germoplasmas analisados, além de estar mais relacionada ao acúmulo de matéria seca. Durante a primavera e verão, a produção de inflorescências mostrou efeito importante na taxa de crescimento de estolões e diferenças entre os germoplasmas foram evidentes. Algumas das populações nativas apresentaram atributos favoráveis que podem ser úteis no melhoramento.

Se tratan aquí dos especies conocidas del género Neocalonyx y se describe una nueva especie, N. diaguita sp. nov. de la provincia de Jujuy (Argentina). Se discuten los caracteres considerados en los tres subgéneros y los cuatro grupos de especies, reconocidos en uno de ellos.Two known species of Neocalonyx genus are dealt with in this paper, and one new species, N. diaguita sp. nov. from Jujuy province in Argentina is described.The characters considered in the three subgenera and the four species groups of one of them are discussed.

During 2004, four experiments were carried out, one each season, in order to determine the species composition and seasonal dynamics of Calliphoridae in a rural area of Córdoba (Argentina). Two pigs (Sus seroja L.), weighing approximately 8 Kg each, were used in each experiment. They were killed with a blow to the head and immediately placed in a variant of the Schoenly et al. (1991) trap. One pig was exposed in the shade and the other one under direct sunlight. The insect fauna was collected daily during the four first weeks and every two or three days thereafter. A total of 16.609 adults of Calliphoridae were collected, and later on identified as one of the following seven species: Chrysomya albiceps (Wiedemann), Chrysomya megacephala (Fabricius), Phaenicia sericata (Meigen), Phaenicia eximia (Wiedemann), Cochliomyia macellaria (Fabricius), Sarconesia chlorogaster (Wiedemann) and Calliphora vicina Robineau-Desvoidy. C. albiceps was the dominant species in summer, autumn and spring, being replaced in winter by C. vicina, S. chlorogaster and P. sericata. The analysis of the seasonal distribution of the species revealed that the greater incidences are in the months of summer, autumn and spring

Se dan a conocer las hembras no descriptas de las especies Arrenurus (Megaluracarus) santafesinus Rosso de Ferradás, 1973 y Arrenurus (Arrhenuropsides) parviscutatus (Viets, 1954). Se brindan redescripciones detalladas de ambas especies. Se mencionan por primera vez para la cuenca argentina del Río Paraná, las especies Arrenurus (Arrhenuropsides) parviscutatus ; Arrenurus (Dadayella) proyecta (Lundblad, 1938); Arrenurus (Megaluracarus) scopularis Lundblad, 1938 y Arrenurus Megaluracarus)gladiiferus Lundblad, 1941, previamente conocidas para Paraguay. Para las especies mencionadas, se amplían las características morfomerísticas mediante comparación con material tipo y se brindan nuevos datos de su distribución geográfica en Argentina.The females of the species Arrenurus (Arrhenuropsides) parviscutatus (Viets, 1954) and Arrenurus (Megaluracarus) santafesinus Rosso de Ferradás, 1973 are described for the first time. Detailed redescriptions of both species are provided. The species Arrenurus (Arrhenuropsides) parviscutatus (Viets, 1954), Arrenurus (Dadayella) projecta (Lundblad, 1938); Arrenurus (Megaluracarus) scopularis Lundblad, 1938 and Arrenurus (Megaluracarus) gladiiferus Lundblad, 1941, described from Paraguay, are mentioned for the first time for Argentina. For the mentioned species, new morphologic characteristics and meassurements by comparison with type material, and new data on their geographic distribution in Argentina are given.

Water mites from Andean part of the Bolivian Amazonian rivers were examined. A new species is described, Limnesia aymara. New records and redescription are made for Hygrobatella multiacetabulata Cook,1980, Atractides brasiliensis (Lundblad, 1937) and Krendowskia convexa (Ribaga, 1902). A new subgenus Schwoerbelobatella for hygrobatelids poliacetabulated is proposed and characterized. Ecological characteristics of the river area sampled and ecological preferences of the analyzed species are discussed.

The Wnt signaling pathway plays a role in the development of the central nervous system (CNS) and growing evidence indicates that Wnts also regulates the structure and function of the adult nervous system. Wnt components are key regulators of a variety of developmental processes, including embryonic patterning, cell specification, and cell polarity. In the nervous system, Wnt signaling also regulates the formation and function of neuronal circuits by controlling neuronal differentiation, axon outgrowth and guidance, dendrite development, synaptic function and neuronal plasticity. Wnt factors can signal through three very well characterized cascades: canonical or β-catenin pathway, planar cell polarity pathway and calcium pathway that control different processes. However, divergent downstream cascades have been identified to control neuronal morphogenesis. In the nervous system, the expression of Wnt proteins is a highly controlled process. In addition, deregulation of Wnt signaling has been associated with neurodegenerative diseases. Here, we will review different aspects of neuronal and dendrite maturation, including spinogenesis and synaptogenesis. Finally, the role of Wnt pathway components on Alzheimer’s disease will be revised.