Abstract Detail

Tropical Biology

DI GRUMO , DAVIDE [1], Montúfar, Rommel [2], Dangles, Olivier [3], Pincebourde, Sylvain [4], Guerrero, Pablo C. [5], Hernandez, Cristian [6], Manzano Santana, Patricia Isabel  [7].

Floral thermogenesis and sexual mimicry in the Ecuadorian ivory palm Phytelephas aequatorialis across primary tropical forests and pastures.

The floral heat production, known as thermogenesis, has a central role in energetically rewarding and signalling to nocturnal pollinators and enhancing scent release, especially in dioecious species. This study accounts for the first description of the thermogenic pattern and female sexual mimicry of both male heat and scent pattern of the dioecious ivory palm P. aequatorialis between a natural and affected environment.   An amount of 18 female and 15 male inflorescences were randomly selected into a primary forest and a nearby cultivated area in Western Ecuador. The floral temperature was continuously monitored for two flowering periods with internal thermocouples, and microclimatic variables were recorded continuously. The floral endothermy and the heat pattern among sexes, environments, and flowering stage were analysed. Finally, the floral scent from both sexes was determined by the solid-phase microextraction technique.   Both sexes of P. aequatorialis inflorescences could reach up to 17°C above air temperature (endothermy) and maintain the heat production for weeks. The large male inflorescences (2m long) stopped heat production immediately after the bud opening, while the no-rewarding and small females gradually decreased floral heat production 2-3 days after blooming. The main climatic distinction between the two habitats were link to the higher humidity of forest habitat. Thus, it was found that the difference between the female and the male floral heat were stronger (until 2°C) in the forest than pasture microhabitat, with female individuals reaching higher temperature than male ones. In pasture, the floral heat was similar between the two sexes, and the males were significantly warmer than the forest ones. The importance of sexual mimicry in female inflorescences was confirmed not only by the temperature patterns, but also by a demonstrated 98% shared floral bouquet (p-methyl anisol) between sexes.   The different pattern of heat production between forest and pasture could have an impact on the pollination effectiveness of this endemic ivory palm, by decreasing the thermal and scent attraction of pollinators. Therefore, the role of humidity on thermogenic flower could be a key climatic parameter for the success of those species which usually live in wet and aquatic environments.

1 - University of Concepción, Botany, Víctor Lamas 1290 Casilla 160-C , Concepción, Región del Bío Bío, 4030000, Chile
2 - Pontificia Universidad Católica del Ecuador, Biological Science - Lab Ecology and Genetics, Quito, Ecuador
3 - IRD France, Biodiversity, fluxes, and global changes, Montpelier, France
4 - University of Tours, Tours, France
5 - University of Concepción, Botany, Concepción, Chile
6 - University of Concepción, zoology, Concepción, Región del Bío Bío, Chile
7 - ESPOL Polytechnic University, Centro de Investigaciones Biotecnológicas del Ecuador (CIBE), Facultad de Ciencias Naturales y Matemáticas (FCNM), Ecuador

thermogenetic flowers
insect pollination
Tropical forest

Presentation Type: Oral Paper
Session: TROP1, Tropical Biology Contributed Papers
Location: Virtual/Virtual
Date: Tuesday, July 28th, 2020
Time: 10:30 AM
Number: TROP1003
Abstract ID:772
Candidate for Awards:None

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