Nectary structure is not related to pollination system in Trichocereeae cactus from northwest Argentina

• Autores: González, Valeria Vanesa; Gorostiague, Pablo; Ortega Baes, Francisco Pablo; Galati, Beatriz Gloria; Ferrucci, María Silvia
• Año de publicación: 2021
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: Anais da Academia Brasileira de Ciencias, 2021, vol. 93, no. 4, p. 1-20.
• Materia: Bird-pollinated; Cactaceae; Floral nectaries; Pollination system; Trichocereeae
• Institución: Universidad Nacional del Nordeste

Fil: González, Valeria Vanesa. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias; Argentina.
Fil: González, Valeria Vanesa. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica del Nordeste; Argentina.
Fil: Gorostiague, Pablo. Universidad Nacional de Salta. Facultad de Ciencias Naturales; Argentina.
Fil: Ortega Baes, Francisco Pablo. Universidad Nacional de Salta. Facultad de Ciencias Naturales; Argentina.
Fil: Galati, Beatriz Gloria. Universidad de Buenos Aires. Facultad de Agronomía; Argentina.
Fil: Ferrucci, María Silvia. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas y Naturales y Agrimensura; Argentina.
Fil: Ferrucci, María Silvia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica del Nordeste; Argentina.
Fl oral nectaries are essential for plant reproduction but little is known about the relationship between these secretory structures and pollination system in cacti. To test phenotypic patterns in nectaries associated with pollination syndromes and/or with its pollinators, we selected from evolutionarily related genera Cleistocactus, Denmoza, and Echinopsis, a set of species with bird-pollinated fl owers and fl oral traits that may fi t with ornithophily or with sphingophily, and other set of sphingophilous species with moths as effective pollinator. Observations were made under light microscope and scanning and transmission electron microscopes. Nectaries are located at the base of the fi laments welded to the tube, forming a chamber. Th e nectary consists of the epidermis with distinctive features in each genus, a secretory parenchyma which may be vascularized and a non-secretory vascularized parenchyma. Anatomical variants observed in nectaries of different species are not consistent with the fl oral pollination syndromes neither with groups of pollinators. The basic structure of the nectar chamber is relatively conserved, a fact that may be explained by phylogenetic conservatism among the genera investigated. Our results revalue the role of anatomical traits for the systematics of Cactaceae.