Calyx (con)fusion in a hyper-diverse genus: Parallel evolution of unusual flower patterns in Eugenia (Myrtaceae)

Autor(es)

Giaretta, Augusto ^[1] ; Vasconcelos, Thais N. C. ^[1] ; Mazine, Fiorella Fernanda ^[2] ; Quintino Faria, Jair Eustaquio ^[3] ; Flores, Rodolfo ^[4] ; Holst, Bruce ^[5] ; Sano, Paulo Takeo ^[1] ; Lucas, Eve ^[6]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biociencias, Dept Bot, Lab Sistemat Vegetal, Rua Matao 277, BR-05508090 Sao Paulo, SP - Brazil

^[2] UFSCar Univ Fed Sao Carlos, Campus Sorocaba, Rod Joao Leme Santos Km 110, BR-18052780 Sorocaba, SP - Brazil

^[3] Univ Brasilia, IB, Dept Bot, BR-70910900 Brasilia, DF - Brazil

^[4] Univ Autonoma Chiriqui, Programa Maestria Biol Vegetal, Chiriqui - Panama

^[5] Marie Selby Bot Gardens, 811 South Palm Ave, Sarasota, FL 34236 - USA

^[6] Royal Bot Gardens, Herbarium, Richmond TW9 3AB, Surrey - England

• Tipo de documento: Artigo Científico
• Fonte: Molecular Phylogenetics and Evolution; v. 139, OCT 2019.
• Citações Web of Science: 2

Resumo

Eugenia has a pantropical distribution and comprises ca. 1000 species found mostly in the Neotropics. Recent DNA based phylogenies show that unusual flower morphology of `eugenioid' collections, e.g. fused calices that open by tearing, consistently emerged within Eugenia. These results emphasize a demand to revaluate flower morphology in a phylogenetic context within the genus. A reassessment of calyx fusion in Eugenia and traditionally related genera is here focused on clarification of the systematic relevance of this apparently recurrent characteristic. Twenty-four Eugenia species with some level of calyx fusion in the bud were newly used (one nuclear and four plastid markers) in conjunction with a representative sample of previously sequenced species to recover a time-calibrated Eugenia phylogeny of 86 accessions. Development of the fused calyx was analysed using scanning electron microscopy, differing patterns were re-coded and subsequently phylogenetic character reconstruction was performed. Eugenia was recovered as monophyletic including the traditionally segregated genera Calycorectes and Catinga. Ancestral character reconstruction uncovered free calyx lobes as the ancestral condition. Five development patterns leading to calyx fusion are reported in Eugenia including species with apparently six petals, which contrast with the standard tetramerous flowers. This condition is interpreted as the petaloid pattern, where two external fused calyx lobes cover the bud while two internal calyx lobes are free and petaloid. The fused calyx condition is homoplastic and evolved independently, several times in Eugenia, as did the different development patterns. Data presented here show that systematic incongruence resulting from multiple, independent origins of the fused calyx in Eugenia is further aggravated by an inability to distinguish parallelism and convergence within the recovered patterns. (AU)

• Processo FAPESP: 16/04678-0 - Filogenia, biogeografia e monografia de Eugenia subg. Calycorectes (O. Berg) Mattos (Myrtaceae)
• Beneficiário: Augusto Giaretta de Oliveira
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Doutorado
• Processo FAPESP: 14/04043-9 - Filogenia, biogeografia e revisão taxonômica de Calycorectes O. Berg (Myrtaceae)
• Beneficiário: Augusto Giaretta de Oliveira
• Modalidade de apoio: Bolsas no Brasil - Doutorado