5 research outputs found
Sobre la presencia de condalia buxifolia (rhamnaceae) y maytenus spinosa (celastraceae) en uruguay
A partir de la revisiĂłn de muestras de herbarios y nuevos relevamientos florĂsticosconcluimos que Maytenus spinosa (Celastraceae), especie citada para la flora deUruguay, fue reiteradamente confundida con Condalia buxifolia (Rhamnaceae),cuya presencia en Uruguay pasĂł inadvertida durante casi un siglo. Maytenus spinosadebe ser excluida de la flora del Uruguay
SOBRE LA PRESENCIA DE CONDALIA BUXIFOLIA (RHAMNACEAE) Y MAYTENUS SPINOSA (CELASTRACEAE) EN URUGUAY
A partir de la revisiĂłn de muestras de herbarios y nuevos relevamientos florĂsticosconcluimos que Maytenus spinosa (Celastraceae), especie citada para la flora deUruguay, fue reiteradamente confundida con Condalia buxifolia (Rhamnaceae),cuya presencia en Uruguay pasĂł inadvertida durante casi un siglo. Maytenus spinosadebe ser excluida de la flora del Uruguay.</div
Chloroplast DNA variation in the Turnera sidoides L. complex (Turneraceae): biogeographical implications
Aim: To analyse the current geographical structure of chloroplast DNA variation in the Turnera sidoides L. complex in order to establish historical biogeographical hypotheses for the midâlatitude South American lowlands. During the Quaternary, the climate shifted from tropical humid to cold dry, and the vegetation cover has not been stable. The consequences of these processes on the current distribution of the vegetation of this area have received very little attention. Location: The midâlatitude South American lowlands extend between c. 20 and 40°S and include Uruguay, northern, central and eastern Argentina, southern Brazil, and parts of southern Paraguay and Bolivia. They are surrounded by higherâelevation systems. Methods: Turnera sidoides is a wellâstudied polyploid complex of perennial rhizomatous herbs occurring throughout the area of interest. We analysed 321 individuals from 79 populations of the five recognized subspecies. We also included progenies from artificial crosses in order to analyse chloroplast inheritance. After screening sequences for four nonâcoding chloroplast DNA regions, the trnLâtrnF spacer was selected to characterize the collection. Results: Three haplotypes can be easily identified, with each differing from the others in two independent characters. A clear geographic structure is revealed when haplotypes are plotted for the complex as a whole regardless of subspecies and cytotype. Three distinct regions can be identified. Main conclusions: We propose three putative refugial areas for the Turnera sidoides complex, which are associated with the orographical systems of the region. Ravines and slopes in the Haedo Cuchilla system in northern Uruguay, the elevations of the western side of the area in Argentina, and the eastern SerranĂas system in southâeastern Uruguay may each have served as refugia in which the A, B and C haplotypes became fixed during the drier climatic phases. Biogeographical patterns in the area covered by T. sidoides, particularly east of the Uruguay River, have not previously been analysed from a historical perspective.
Locationâ The midâlatitude South American lowlands extend between c. 20 and 40°S and include Uruguay, northern, central and eastern Argentina, southern Brazil, and parts of southern Paraguay and Bolivia. They are surrounded by higherâelevation systems.
Methodsâ Turnera sidoides is a wellâstudied polyploid complex of perennial rhizomatous herbs occurring throughout the area of interest. We analysed 321 individuals from 79 populations of the five recognized subspecies. We also included progenies from artificial crosses in order to analyse chloroplast inheritance. After screening sequences for four nonâcoding chloroplast DNA regions, the trnLâtrnF spacer was selected to characterize the collection.
Resultsâ Three haplotypes can be easily identified, with each differing from the others in two independent characters. A clear geographic structure is revealed when haplotypes are plotted for the complex as a whole regardless of subspecies and cytotype. Three distinct regions can be identified.
Main conclusionsâ We propose three putative refugial areas for the Turnera sidoides complex, which are associated with the orographical systems of the region. Ravines and slopes in the Haedo Cuchilla system in northern Uruguay, the elevations of the western side of the area in Argentina, and the eastern SerranĂas system in southâeastern Uruguay may each have served as refugia in which the A, B and C haplotypes became fixed during the drier climatic phases. Biogeographical patterns in the area covered by T. sidoides, particularly east of the Uruguay River, have not previously been analysed from a historical perspective.Fil: Speranza, Pablo R.. Universidad de la RepĂșblica; UruguayFil: Seijo, JosĂ© Guillermo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BotĂĄnica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de BotĂĄnica del Nordeste; Argentina. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; ArgentinaFil: Grela, IvĂĄn A.. Universidad de la RepĂșblica; UruguayFil: Solis Neffa, Viviana Griselda. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BotĂĄnica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de BotĂĄnica del Nordeste; Argentin