Abstract Detail

Systematics

Guerra, Ethiéne [1], Soares, Marcos Vinicius Batista [2], Morim, Marli Pires [3], Iganci, Joao [2].

Phylogenetic placement of Abarema s.s. (Caesalpinioideae, mimosoid clade).

Abarema Pittier used to be considered as a monophyletic genus, and the morphological features used to delimit and circumscribe the genus were considered as robust. The first molecular analyses focused on the Abarema Alliance (Tribe Ingeae), showed the genus Abarema as polyphyletic. The type species of Abarema, Abarema cochliacarpos (Gomes) Barneby & J.W.Grimes, segregated from the remaining species of Abarema s.l., strongly sustained as part of the Inga Alliance. Aiming to understand the relationships of Abarema s.s. within the Inga Alliance, and to provide the phylogenetic placement of the genus Abarema, we applied molecular phylogenetic analysis using both plastidial matK and nuclear ETS sequences. A combined Bayesian analysis of ETS and matK sequences was implemented in MrBayes 3.2.6. The ingroup sampling is compound by Abarema cochliacarpos, Enterolobium schomburgkii (Benth.) Benth., and species of Macrosamanea Britton & Rose ex Britton & Killip,Inga Mill., and Zygia P.Browne. For the out-group, we choose Samanea saman (Jacq.) Merr. (from the tribe Ingeae, but not closely related to the Inga Alliance), accessions of Abarema s.l. (A. langsdorffii (Benth.) Barneby & J.W.Grimes, A. filamentosa (Benth.) Pittier and A. centiflora Barneby & J.W.Grimes), besides Hydrochorea corymbosa (Rich.) Barneby & J.W.Grimes, from the former Abarema Alliance. The genera Calliandra Benth., Zapoteca H.M.Hern. and other species of Entereloboium Mart. were not sampled. Although these taxa are traditionally included in the Inga Alliance, recent molecular phylogenetic studies highlighted that they are not part of this Alliance. The phylogenetic analysis showed Abarema s.s. close related to the Inga Alliance. A. cochliacarpos grouped together with the samples of Inga Alliance with 100% of posterior probabilities. Abarema emerged as sister to the Amazonian genus Macrosamanea with 92% of posterior probability. The remaining taxa from the extinct Abarema Alliance grouped next to Samanea saman in the out-group. Morphologically, the capitate raceme present in Abarema s.s. is recurrent in species of the Inga Alliance, including Zygia, Macrosamanea and Enterolobium, besides being less common in Inga.  In the Ingeae tribe, the fruits are one of the most important characters to distinguish the genera, whereas vegetative characters are strongly similar between the species and genera. Future morphological analyses combined with more robust molecular analyses are essential to achieve a more comprehensive systematic organization of the Alliances within the tribe Ingeae.

1 - Universidade Federal do Rio Grande do Sul, Departamento de Botânica, Av. Bento Gonçalves, 9500 - Bloco IV - Prédio 43433, sala 112. 91501-970, Porto Alegre, Rio Grande do Sul, 91501-970, Brazil
2 - Universidade Federal do Rio Grande do Sul, Departamento de Botânica, Av. Bento Gonçalves, 9500 - Bloco IV - Prédio 43433, sala 112. 91501-970, Porto Alegre, Rio Grande do Sul, 91501-970, Brasil
3 - Instituto de Pesquisa Jardim Botânico do Rio de Janeiro, Rua Pacheco Leão, 915, Jardim Botânico, Rio de Janeiro, Rio de Janeiro, Brasil

Keywords:
Inga Alliance
matK
ETS
Abarema Alliance
Tribe Ingeae.

Presentation Type: Poster
Session: P, Systematics Posters
Location: Arizona Ballroom/Starr Pass
Date: Monday, July 29th, 2019
Time: 5:30 PM This poster will be presented at 6:15 pm. The Poster Session runs from 5:30 pm to 7:00 pm. Posters with odd poster numbers are presented at 5:30 pm, and posters with even poster numbers are presented at 6:15 pm.
Number: PSY002
Abstract ID:128
Candidate for Awards:None