We analyzed the microgametogenesis and microsporogenesis of the male flowers of the holoparasitic Helosis cayennensis (Sw.) Spreng. var. cayennensis using optical and scanning electron microscopy. The unisexual flowers are embedded in a dense mass of uniseriate trichomes (filariae). Male flowers have a tubular 3-lobed perianth, with bilayered and non vascularized tepals. The androecium consists of three stamens with filaments and thecae connated into a synandrium. It has adnate a free central pistillode without megagametophyte. Staminal filaments, fused at their base to the perianth tube and distally free along a short section, have a single vascular bundle. The distal portion of the synandrium is formed by nine pollen sacs: six outer sacs are located laterally to each filament and three longer inner sacs. The anther wall consists of the epidermis, two parietal layers (that collapse at anther maturity), and an uninucleate secretory tapetum. There is no endothecium. During microsporogenesis, the stem cells produce tetrads of microspores by meiosis. The cytokinesis is simultaneous, forming tetrahedrally arranged tetrads. When pollen grains are in the tricellular state, the synandrium emerges from the mass of filariae, and anthers dehiscence occurs apically through longitudinal slits. In conclusion, despite the extreme reduction of flowers, the anatomic characteristics and gametophyte development of staminate flowers of H. cayennensis are perfectly normal and functional. They are thus highly similar to other genera of the holoparasitic subfamily Helosidoideae. Sterile parts of flowers and inflorescence maintain the same distinctive and aberrant features of the plant vegetative parts.
<p>Este trabajo tiene como objetivo mostrar una serie de acciones de vinculación y trasferencia realizadas por un grupo interdisciplinario de profesionales. Estos pertenecen a FaCENA y FCA (UNNE), CONICET, INTA, e INTI. Incluye también una componente docente que busca formar, en tareas extensionistas, a los estudiantes de grado involucrados en los Proyectos del Programa “La Universidad en el Medio”. Tiene como finalidad dar a conocer la calidad de las mieles chaqueñas, principalmente las producidas en el Sitio Ramsar y localidades cercanas, asociada al origen floral para generar estrategias de implementación de valor agregado. Con el abordaje de diferentes problemáticas en la producción de miel, las acciones se realizaron con un grupo apicultores del Chaco, que pertenecen a dos cooperativas (COPAP [Margarita Belén] y Los Palmares [Basail]) y a una asociación apícola (Asociación de Productores Apícolas [Charadai]). Esta última no está incluida dentro del Sitio Ramsar. Todas las intervenciones apostaron al fortalecimiento del sector apícola de la región, mejorar la producción y aumentar el consumo de miel principalmente. Durante las jornadas de la “Semana de Miel”, se difundió sobre las propiedades naturales de los productos apícolas, además de fomentar el consumo de los productos primarios de las abejas y sus derivados. Se realizaron acciones con niños del nivel inicial promoviendo el consumo de miel, el cuidado y protección de las abejas como agentes polinizadores y conservadores de la biodiversidad.</p>
This article is the first contribution to the characterization of monofloral honeys from the Dry and Humid Chaco that combines palynological and physicochemical parameters. The study focuses on the most represented honeys. Physicochemical parameters such as color, electrical conductivity, moisture, acidity and pH were analyzed for a total of 116 honeys classified as monofloral by pollen analysis. All the parameters considered were within the accepted range. Color and electrical conductivity were the most distinctive features, as stressed by multivariate (cluster analysis (CA) and principal component analysis (PCA)) and correlation analysis. The darkest honeys (i.e. black, dark amber and amber) were those from Tessaria integrifolia, Schinopsis balansae, S. lorentzii and Baccharis–Eupatorium-type pollen, and the lightest honeys (i.e. light amber and extra light amber) were those from Cynophalla retusa, Eugenia uniflora, Copernicia alba, Prosopis alba and Helianthus annuus. Mean values for electrical conductivity ranged from 0.4 to 0.8mS cm–1, with the highest values detected in the darkest honeys, which are mainly produced in the Dry Chaco. The intense color of these honeys also suggests the presence of antioxidants. Thus, the color, electrical conductivity and antioxidant properties are important factors for future research to consider, to obtain a reliable authentication of the botanical and geographical features of these honeys.
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