Disentangling the pollination system of the food-deceptive orchid Anacamptis longicornu (Orchidaceae): from breeding system to spatio-temporal variation in reproductive success

Abstract

The deceptive breeding system in the Orchidaceae family has been studied for decades to disentangle how pollination service can occur. Moreover, the interference of introduced herbivores on population development has been reported to affect the reproductive output in different plant species, including orchids. In this study, the breeding system of the food-deceptive species Anacamptis longicornu has been assessed. The spatio-temporal variation in both male and female reproductive fitness and its relationship with plant features were also analyzed. The possible herbivory effects were investigated by an exclusion experiment using two types of cages. The results confirm that this species is pollinator dependent and mostly allogamous but is also self-compatible. This species showed high values of cumulative inbreeding depression index for fruit set and seed viability parameters and was highly pollen-limited. Male fitness was always higher than female fitness between years and locations, and both parameters showed spatio-temporal variation. The use of cages excluded herbivores but, eventually, also excluded pollinators, so that both male and female reproductive success parameters decreased significantly in the complete exclusion treatment. The strong dependence of the species’ fitness on pollinator-mediated pollen transfer must be considered for the long-term conservation of A. longicornu.

Keywords:

• Balearic Islands
• reproductive biology
• inbreeding depression
• grazing exclusion
• pollinator-dependence

Acknowledgments

The authors are grateful to the owners of Son Doblons and Son Mut Nou for facilitating access to the study sites. We are very grateful to anonymous reviewers for their valuable contributions that have allowed to improve an earlier version of the manuscript. The English language has been revised by American Journal Experts (Certificate Verification Key 340A-3CFD-A2C5-1BD3-061E).

Disclosure statement

The authors declare that they have no potential conflict of interest.

Additional information

Funding

This research was executed as a part of MC’s Ph.D. thesis by fellowship FPI/1925/2016 through Direcció General d’Innovació i Recerca (Govern de les Illes Balears). It also has been partially funded by Project CGL2015-70449-R (Ministerio de Economía y Competitividad, Gobierno de España).