title: Reproductive biology and nectar production of the Mexican endemic Psittacanthus auriculatus (Loranthaceae), a hummingbird-pollinated mistletoe.
abstract: Many mistletoe species produce 'bird'-pollinated flowers; however, the reproductive biology of the majority of these species has not been studied. Psittacanthus auriculatus is a Mexican endemic mistletoe, most common in open, dry mesquite grassland. Knowledge of the reproductive biology of P. auriculatus is essential for understanding species formation and diversification of Psittacanthus mistletoes, but it is currently poorly understood. Thus, we studied floral biology and phenology, nectar production and breeding system and pollination of this species. The hermaphroditic red-pink flowers open from the middle to the tip and petals are curly, but remain partially fused forming a floral tube of ca. 20-mm long. Flowers are partially protandrous, produce large amounts of nectar, last 2 days, and stigma receptivity is highest during the second day. We recorded hummingbirds (Cynanthus latirostris, Hylocharis leucotis, Amazilia beryllina, A. violiceps, Calothorax lucifer, Archilochus colubris) and less commonly butterflies (Agraulis vanillae, Anteos clorinde, Papilio multicaudatus, Phocides urania, Phoebis sennae) as floral visitors. P. auriculatus flowers are self-compatible. However, this mistletoe is an obligate animal-pollinated species, as the sensitive stigma avoids self-pollination. Under natural conditions, reproductive success was higher than in manually selfed or cross-pollinated flowers, likely due to the traplining foraging behaviour of hummingbirds. We suggest that the apparent efficient foraging behaviour of hummingbirds maintains gene flow among P. auriculatus, promoting outcrossing.
authors.affiliation: Departamento de Biología Evolutiva, Instituto de Ecología, A.C. (INECOL), Xalapa, Veracruz, Mexico.|Centro de Investigación en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, San Felipe Ixtacuixtla, Tlaxcala, Mexico.
authors.forename: M J
authors.initials: MJ
authors.lastname: Pérez-Crespo
authors.affiliation: Departamento de Biología Evolutiva, Instituto de Ecología, A.C. (INECOL), Xalapa, Veracruz, Mexico.
authors.forename: J F
authors.initials: JF
authors.lastname: Ornelas
authors.affiliation: Departamento de Biología Evolutiva, Instituto de Ecología, A.C. (INECOL), Centro Regional del Bajío, Pátzcuaro, Michoacán, Mexico.
authors.forename: S
authors.initials: S
authors.lastname: Martén-Rodríguez
authors.affiliation: Laboratorio de Genética de la Conservación, Centro de Investigaciones en Ecosistemas (CIECO), UNAM, Morelia, Michoacán, Mexico.
authors.forename: A
authors.initials: A
authors.lastname: González-Rodríguez
authors.affiliation: Centro de Investigación en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, San Felipe Ixtacuixtla, Tlaxcala, Mexico.
authors.forename: C
authors.initials: C
authors.lastname: Lara
mesh_terms: D000818:Animals; D001717:Birds; D035264:Flowers / Q000502:physiology; D028183:Loranthaceae / Q000502:physiology*; D008800:Mexico; D014784:Mistletoe / Q000502:physiology; D057048:Plant Nectar / Q000378:metabolism*; D054817:Pollination / Q000502:physiology*
chemical_list: D057048:Plant Nectar
keywords: Floral biology; Loranthaceae; Psittacanthus; Trochilidae; hummingbird pollination; pollination syndromes