Evolution of pollination by frugivorous birds in Neotropical Myrtaceae

NADRA, MARÍA GABRIELA; GIANNINI, NORBERTO PEDRO; ACOSTA, JUAN MANUEL; AAGESEN, LONE

PeerJ

CREATIVECOMMONS

Año: 2018 vol. 6 p. 1 - 22

Bird pollination is relatively common in the tropics, and especially in the Americas.In the predominantly Neotropical tribe Myrteae (Myrtaceae), species of two genera,Acca and Myrrhinium, offer fleshy, sugary petals to the consumption of birds thatotherwise eat fruits, thus pollinating the plants in an unusual plant-animal interaction.The phylogenetic position of these genera has been problematic, and therefore, so wasthe understanding of the evolution of this interaction. Here we include new sequencesof Myrrhinium atropurpureum in a comprehensive molecular phylogeny based on abalanced sample of two plastid and two nuclear markers, with the aim of providingthe historical framework of pollination by frugivorous birds in Myrteae. We developed13 flower and inflorescence characters that comprehensively depict the macroscopicmorphological components of this interaction. Bayesian and parsimony phylogeniesconcur in placing both Acca and Myrrhinium in a clade with Psidium species; withMyrrhinium sister to Psidium. Mapping of morphological characters indicated somedegree of convergence (e.g., fleshy petals, purplish display) but also considerabledivergence in key characters that point to rather opposing pollination strategies andalso different degrees of specialization in Acca versus Myrrhinium. Pollination byfrugivorous birds represents a special case of mutualism that highlights the evolutionarycomplexities of plant-animal interactions.