Origin and ontogeny of the extrafloral nectaries associated to the inflorescences of Vigna Candida and Vigna Caracalla (Leguminosae, Phaseoleae)

• Autores: Ojeda, Fabiana Soledad; Hoc, Patricia Susana; Galati, Beatriz Gloria; Amela García, María Teresa
• Año de publicación: 2015
• Idioma: inglés
• Tipo de recurso: artículo
• Fuente: International Journal of Advanced Research in Botany (IJARB); Vol.1, no.1; 33-41; https://www.arcjournals.org
• Materia: VIGNA CANDIDA; VIGNA CARACALLA; EXTRAFLORAL NECTARY DEVELOPMENT; HISTOLOGY; CITOLOGY
• Institución: Universidad de Buenos Aires. Facultad de Agronomía

Fil: Ojeda, Fabiana Soledad. Proplame-Prhideb (Conicet); Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencia Exactas y Naturales, Universidad de Buenos Aires Intendente Güiraldes CABA, Argentina.
Fil: Hoc, Patricia Susana. Proplame-Prhideb (Conicet); Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencia Exactas y Naturales, Universidad de Buenos Aires Intendente Güiraldes CABA, Argentina.
Fil: Galati, Beatriz Gloria. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Recursos Naturales y Ambiente. Cátedra de Botánica. Buenos Aires, Argentina.
Fil: Amela García, María Teresa. Proplame-Prhideb (Conicet); Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencia Exactas y Naturales, Universidad de Buenos Aires Intendente Güiraldes CABA, Argentina.
The morphology, ontogeny and secretion of the extrafloral nectaries (EFNs) in the inflorescences of Vigna candida and Vigna caracalla were studied. The nodes along the inflorescences were processed with standard techniques for light as well as scanning and transmission electron microscopy. In each node, several EFNs are formed between the flowers. The EFNs originate from flower buds that stop their growth and detach, leaving an orifice bellow which there are longitudinally enlarged cells (central cells) surrounded by a circular mound (ring). Both zones secrete. Four ontogenetic stages succeed, being the third the secretory one. In each node, different EFNs are in different stages of development simultaneously, so there is always a functional nectary accompanying the flowers buds, the flowers in anthesis or the maturing fruits. Ultrastructure characteristics suggest that secretion follows the granulocrine pathway. The two studied species, together with Vigna adenantha, which belong to the same subgenus, share the most important characters, but differ from the corresponding ones of Vigna luteola, which is placed in a different subgenus, so the EFN traits support the current classification. This is the first report about taxonomic implications of the EFNs of New World species of Vigna.
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