Oliveira et al. 2018 (Article) Bromelioidae

Morphoanatomical characters in the Nidularioid Complex (Bromeliaceae: Bromelioidae) from a phylogenetic perspective

Author(s):—F.M.C. Oliveira, R.B. Louzada, M.G.L. Wanderley & G.F.A. Melo-de-Pinna

Publication:—Flora 239: 111–121 (online 2017). (2018) — DOI

Abstract:—The Nidularioid complex, as formed by the genera Nidularium Lem., Wittrockia Lindm., Neoregelia L.B.Sm., Canistropsis (Mez) Leme and Edmundoa Leme, is a Bromelioideae group known for its difficult generic delimitation. This difficulty is attributed to the large number of nonexclusive characters that are used in these genera, which demonstrates their intimate relationship. In current phylogenies, the genera belonging to the Nidularioid complex always emerge as a unified group termed as ‘Nidularioid Clade'. This study aims to reconstruct usual morphological characters in Bromelioideae, as well as anatomical characters from the leaf sheath and blade of species from the Nidularioid complex, in order to propose new synapomorphies for the group. To accomplish this, we proposed a phylogenetic hypothesis that used chloroplastidial atpB-rbcL, matK, trnL-trnF and nuclear PhyC gene sequences obtained from the NCBI portal in a Bayesian analysis that resulted in a consensus tree. We also used parsimony and Bayesian methods to reconstruct previously delimited morphoanatomical characters. Our results indicate that the morphological characters typically used in the group's taxonomy represent homoplasies. Some anatomical characters are also homoplastic, such as the number of layers in the abaxial mechanical hypoderm from the leaf sheath. However, leaf anatomy provided new synapomorphies for the group, such as the presence of trichomes with elongated wing cells, the presence of adaxial epidermal cells with slightly thickened walls on the leaf blade and brachiform cells with long branches in the leaf sheath region. Thus, this paper presents new perspectives for future studies on the evolution of characters in the Nidularioid complex.

Keywords:—Ancestral state reconstruction Bromelioideae Evolution Synapomorphies