Abstract Detail

Ecology

Sánchez-Collazo, Xiumy Michelle [1], Figueroa-Castro, Dulce [2], Cruz, J. Alberto [2], López Tellez, María Concepción [2].

Floral morphology and pollinator-mediated interactions between two chiropterophilic cacti in Central Mexico.

Pollination interactions influence the composition, and diversity of species in plant communities. Such influence is not only determined by the interactions established between plants and their pollinators, but also by interactions mediated through pollinators among plant species that flower simultaneously. In this case, two possible interactions might occur between plant species: competition or facilitation. As floral morphology of the plant species involved is more similar, the chances of a competitive interaction increase. However, if the co-flowering species have different floral morphology, it might be possible that either they have different pollinators, or if they are pollinated by the same one, pollen might be placed in distinct body parts, thus plant species might keep a facilitative interaction mediated through the sustainment of the shared pollinator. The type of interaction established between plant species within a community might also depend on the availability of pollinators and the diversity of co-flowering plant species; such that competition is more commonly found in tropical habitats, whereas facilitation predominates in arid ones.  Stenocereus pruinosus  and  Marginatocereus marginatus  are two species of columnar cactus with quiropterophilous pollination syndrome, that flower simultaneously in an arid region in Central Mexico. The goal of this study was characterize and compare the floral morphology of the two cacti species to infer the type of interaction that might be occurring between them. Twenty flowers from each species were collected. Both lineal and geometric morphometry analyses were used to compare floral morphology between species. Lineal traits included: floral tube length with and without nectary; floral tube diameter; stile, stamen and nectary length; circumference and area on the top, medium distance and base of the floral tube, and area of the floral tube on lateral view. Floral shape was determined on lateral view of the floral tube. The lineal morphometric analyses showed that all traits were significantly greater in S. pruinosus  than in  M. marginatus. Moreover, geometric morphometry analyses showed that the floral tube in  S. pruinosus  is campanulated, whereas in  M. marginatus  it is narrow and straight throughout all its length. Our results showed that the cacti species studied have different floral morphology, suggesting the lack of a competitive interaction between them. Instead, it is possible that  S. pruinosus  and  M. marginatus  maintain a facilitative interaction mediated through the sustainment of their bat pollinators. Alternatively, it is possible that each of these cacti species might be pollinated by different bat species.

1 - Benemérita Universidad Autónoma de Puebla , Maestría en CB, Facultad de CB, Blvd. Valsequillo y Av. San Claudio, Ed. BIO 1 CU, Col. Jardines de San Manuel, Puebla, Puebla, 72570, Mexico
2 - Benemérita Universidad Autónoma de Puebla, Facultad de CB, Blvd. Valsequillo y Av. San Claudio, Ed. BIO 1 CU, Col. Jardines de San Manuel, Puebla, Puebla , 72570, Mexico

Keywords:
competition
facilitation
Stenocereus pruinosus
Marginatocereus marginatus.

Presentation Type: Oral Paper
Session: ECO7, Ecology: Reproductive Biology
Location: /
Date: Thursday, July 22nd, 2021
Time: 4:30 PM(EDT)
Number: ECO7007
Abstract ID:177
Candidate for Awards:None