Key functional floral traits in the early-divergent angiosperm family Annonaceae: gynoecial diversity and the evolution of strategies that promote pollination efficiency and pollen competition

Dr Gaitan Espitia, Juan Diego   (Principal Investigator (PI))

Dr Xue Bine   (Co-Investigator)

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2021-01-01

1154271

Key functional floral traits in the early-divergent angiosperm family Annonaceae: gynoecial diversity and the evolution of strategies that promote pollination efficiency and pollen competition

evolution, floral morphology, pollen competition, pollination ecology, stigma proteome

Biodiversity and SystematicsEcology

Biology and Medicine (M)

17112720

General Research Fund (GRF)

2020

On-going

1 To determine the phylogenetic occurrence of extragynoecial compita (EGC) across the Annonaceae, distinguishing between: (a) suprastylar EGC, in which stigmas are either closely appressed or connected by stigmatic exudate; and (b) putative infrastylar EGC, in which flowers are likely to show basal placentation. 2 To evaluate the occurrence of complete or partial syncarpy in the family, with emphasis on putative syncarpy in Cyathocalyx by comparing its gynoecial development and vasculature with that of its unequivocally apocarpous sister genus, Drepananthus. 3 To assess evidence for competition between pollen derived from geitonogamous vs xenogamous pollination in Annonaceae flowers, with emphasis on: (a) the role of putative ‘pseudostyles’; and (b) ‘passive’ pollen discrimination in protogynous flowers in which there is a temporal overlap between the pistillate and staminate phenological phases. 4 To evaluate whether there are selective advantages associated with contrasting seed dispersal units, and whether this might explain the retention of an apocarpous gynoecium in the Annonaceae. 5 To infer likely functions of Annonaceae stigmatic exudate using an integrated quantitative proteomics and transcriptomics analysis, enabling comparisons with published data for more derived monocot and eudicot lineages. 6 To evaluate correlations between floral traits (including phylogenetically independent contrasts) to identify alternative strategies for promoting pollination efficiency and offspring quality in the Annonaceae. 7 To integrate the data generated with existing data on the phylogeny and reproductive biology of the Annonaceae to identify putative key functional floral traits that are correlated with significant diversification rate shifts.