Pollination Ecology and Breeding System of Xylopia championii (Annonaceae): Curculionid Beetle Pollination, Promoted by Floral Scents and Elevated Floral Temperatures

Abstract

Data on the reproductive biology of the Annonaceae are rather fragmentary, particularly for paleotropical species. The pollination ecology and breeding system of the Sri Lankan endemic Xylopia championii (Annonaceae) are described in detail. The pollination ecology was investigated using a diverse range of approaches, including (1) observations of flower‐level and population‐level phenology, (2) assessments of floral visitors and effective pollinators, (3) monitoring of floral temperature in situ using a digital data logger, and (4) analysis of scent chemistry using solid‐phase microextraction sampling and gas chromatography–mass spectrometry identification of volatiles. The breeding system was evaluated using pollen/ovule ratios and field‐based controlled‐pollination experiments. Intrafloral dichogamy (protogyny) occurs over a 2‐d period, with a reproductively inactive phase between the pistillate and staminate phases, although there is no evidence of interfloral dichogamy. The inner petals close to form...