https://hdl.handle.net/20.500.11984/475 Tue, 07 Jul 2026 21:18:25 GMT 2026-07-07T21:18:25Z https://hdl.handle.net/20.500.11984/14598 Niche conservatism, divergence and polyploidy in Senna series Aphyllae (Fabaceae: Caesalpinioideae) from arid zones of South America Moro Cordobes, Fernando This paper aims to integrate cytogenetic and ecological approaches into a phylogenetic framework to better understand the evolution and systematics of Senna series Aphyllae, an endemic group of arid and semi-arid regions of South America. We counted the chromosome numbers at the population level in three species of series Aphyllae using a conventional technique (GIEMSA) and in situ hybridization (FISH). Phylogenetic reconstructions and inference of chromosome evolution were based on four plastid DNA regions and one nuclear marker. A principal component analysis was carried out using environmental data. Finally, ecological niche models (ENM) were implemented: (1) to identify the abiotic factors that constraint the potential geographical distribution of series Aphyllae and (2) to understand the ecological drivers for species diversification. The basic chromosome number is x = 12. Senna aphylla showed three cytotypes with (2n = 24, 48 and 60) and S. pachyrrhiza has two cytotypes (2n = 24 and 48). Senna crassiramea appeared to be polyploid with 2n = 48. In diploid S. pachyrrhiza, two 45S and three 5S rDNA sites were reported. In tetraploid S. crassiramea, four 45S and four 5S rDNA sites were detected. The ENM and ecological speciation tests suggest that in series Aphyllae speciation was sometimes associated with conservatism and sometimes with niche divergence. Our results contribute to the evolutionary knowledge of Neotropical legumes and understanding of drivers of diversification in arid regions in South America. Sat, 01 Jan 2022 00:00:00 GMT https://hdl.handle.net/20.500.11984/14598 2022-01-01T00:00:00Z https://hdl.handle.net/20.500.11984/14580 Preliminary report on the allelopathic potential of South American Imperata species (Poaceae: Andropogoneae); Estudio preliminar sobre el potencial alelopático de las especies sudamericanas de Imperata (Poaceae: Andropogoneae) Moro Cordobes, Fernando Background: A significant number of species of grasses (Poaceae) have allelopathic properties and two genera of Andropogoneae -Cymbopogon and Bothriochloa- are the main aromatic genera recognized in the family. The genus Imperata (Poaceae: Andropogoneae) is widely distributed, with several species being present around the world. Questions and / or Hypotheses: This study assessed the allelopathic potential of some South American species of Imperata taking into account previous reports on I. cylindrica, which has been extensively studied due to its invasiveness and allelopathic potential. Studied species / data description /Mathematical model: I. brasiliensis, I. condensata, I. minutiflora, and I. tenuis Study site and dates: Greenhouse of the Instituto Multidisciplinario de Biología Vegetal, Sistemática y Filogeografía de Plantas, Córdoba, Argentina. Methods: We obtain the aqueous extract from the studied species and we evaluated its effect on germination and root and shoot growth of lettuce, corn, and tomato. Results: In bioassays, aqueous leaf extract of I. brasiliensis, I. condensata, I. minutiflora, and I. tenuis inhibited seed germination and root and shoot growth of lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and maize (Zea mays). The extracts mainly affected root and shoot length, whereas the effect on seed germination was low. Conclusions: The studied species may contain allelochemicals, which interfere with seed germination and seedling growth. Future research on the type of chemical compounds present in aqueous extracts may contribute to their use for agroecological purposes.; Antecedentes: Un número importante de especies de gramíneas (Poaceae) tienen propiedades alelopáticas y dos géneros de Andropogoneae -Cymbopogon y Bothriochloa- son los principales géneros aromáticos reconocidos en la familia. El género Imperata (Poaceae: Andropogoneae) está ampliamente distribuido con varias especies presentes en todo el mundo. Preguntas y / o Hipótesis: En este estudio se evaluó el potencial alelopático de algunas especies sudamericanas de Imperata teniendo en cuenta los estudios realizados sobre I. cylindrica, la cual ha sido ampliamente estudiada debido a su cualidad de invasora y su potencial alelopático. Especies de estudio / Descripción de datos / Modelo matemático: I. brasiliensis, I. condensata, I. minutiflora y I. tenuis. Métodos: Obtuvimos el extracto acuoso de las especies estudiadas y evaluamos su efecto sobre la germinación y el crecimiento de raíces y brotes de lechuga, maíz y tomate. Resultados: En los bioensayos, los extractos acuosos de las hojas de I. brasiliensis, I. condensata, I. minutiflora e I. tenuis inhibieron la germinación de las semillas y el crecimiento de las raíces y los brotes de la lechuga (Lactuca sativa), el tomate (Solanum lycopersicum) y el maíz (Zea mays). Los extractos afectaron principalmente a la longitud de las raíces y los brotes, mientras que el efecto sobre la germinación de las semillas fue débil. Sitio y años de estudio: Invernadero del Instituto Multidisciplinario de Biología Vegetal, Sistemática y Filogeografía de Plantas, Córdoba, Argentina. Conclusiones: Las especies estudiadas pueden contener aleloquímicos que interfieren en la germinación de las semillas y en el crecimiento de las plántulas. Futuras investigaciones sobre el tipo de compuestos químicos presentes en los extractos acuosos pueden contribuir a su uso con fines agroecológicos Sun, 01 Jan 2023 00:00:00 GMT https://hdl.handle.net/20.500.11984/14580 2023-01-01T00:00:00Z https://hdl.handle.net/20.500.11984/14578 Effect of Farnesol and Octenol on Mycelium Differentiation Moro Cordobes, Fernando Hyphal systems have been essential for the morphoanatomical characterization of basidiomes and mycelia of aphyllophoroid fungi for taxonomic purposes. They have also been shown to influence the consistency of basidiomes. Recent developments in areas such as mycelium composite production as sustainable materials have redirected scientists’ attention to these structures, particularly regarding their material resistance, where complex hyphal systems enhance the properties of these composites. Compounds such as farnesol and octenol trigger growth and differentiation processes in many fungal groups, and laccases have been proposed as enzymes involved in these processes, given their roles in the synthesis of cell wall pigments and other cell wall components. Given the easily quantifiable differences in hyphal knots and dimitic mycelium between Fuscoporia torulosa and Inocutis tamaricis, we employed them as models to study their responses to these compounds, thereby helping fill the knowledge gap in the modulation of macrofungal mycelial differentiation. A variable effect was observed on laccase induction, while radial growth was reduced by octenol by up to 83% in F. torulosa and 65% in I. tamaricis, and by farnesol by up to 80% in I. tamaricis, showing slight effects on F. torulosa. Reductions of up to 100% were observed in the combination of high doses of both chemicals. Thu, 01 Jan 2026 00:00:00 GMT https://hdl.handle.net/20.500.11984/14578 2026-01-01T00:00:00Z https://hdl.handle.net/20.500.11984/14577 Rediscovery of the Patagonian mushroom Austroomphaliaster nahuelbutensis 41 years after the type collection; Redescubrimiento del hongo patagónico Austroomphaliaster nahuelbutensis 41 años despuésde la colección tipo Moro Cordobes, Fernando Erected by Garrido in 1988, the genus Austroomphaliaster contains a single species, A. nahuelbutensis, which has not been cited again since its original description. Despite numerous expeditions across the Nothofagus forests, the species remains unlocated, and no morphological or molecular studies of the type have been published ever since. In 2023, an expedition led by the Fungi Foundation aimed to search for this lost species, resulting in the collection of two specimens consistent with the original description. One year later, mycologists from the University of Concepción found the same species a few kilometers from the type locality. A morphological revision of the reference materials, along with a phylogenetic study that included type ITS and LSU sequences, confirmed its identity. Our study places this putatively saprotrophic species within the family Fayodiaceae. Austroomphaliaster nahuelbutensis appears to have a very restricted distribution and should be included in conservation programs.; Erigido por Garrido en 1988, el género Austroomphaliaster contiene una sola especie, A. nahuelbutensis, que no ha vuelto a citarse desde la descripción original. Numerosas campañas a lo largo de los bosques de Nothofagus no han podido volver a encontrarlo, y ningún estudio morfológico ni molecular del tipo se ha publicado desde entonces. En 2023, una campaña a la localidad tipo en Nahuelbuta fue liderada por la Fundación Fungi con el objetivo de buscar esta especie perdida, y resultó en el hallazgo de dos especímenes congruentes con la descripción original. Un año después, micólogos de la Universidad de Concepción encontraron la misma especie a algunos km de la localidad tipo. La revisión morfológica del material de referencia confirmó la identidad junto con el estudio filogenético que incluyó secuencias de ITS y LSU del tipo. Nuestro estudio ubica esta especie aparentemente saprotrófica en la familia Fayodiaceae. Austroomphaliaster nahuelbutensis parece tener una distribución muy limitada y debe ser incluido en programas de conservación. Wed, 01 Jan 2025 00:00:00 GMT https://hdl.handle.net/20.500.11984/14577 2025-01-01T00:00:00Z