Goetze et al. 2015 (Conference Paper) Aechmea

Phylogeography and population differentiation of seven Aechmea species from the Atlantic Rainforest

Author(s):—M. Goetze, C.M. Zanella, C. Palma-Silva, M.V. Büttow & F. Bered in Benko-Iseppon, A.M.; Alves, M. & Louzada, R. (2015) An overview and abstracts of the First World Congress on Bromeliaceae Evolution. Rodriguésia 66(2): A1-A66.

Publication:— (2015).

Abstract:—Aechmea subgenus Ortgiesia has ca. 17 species, which possess yellow, blue, pink, or white petals. Yellow-flowered Ortgiesia
are almost all restricted to the southern region of the Brazilian Atlantic Rainforest, where some of them overlap in geographical
distribution. They blossom mainly during the autumn (March-June), some species share pollinators, and taxa boundaries are difficult
to identify, especially where they are found in sympatry. Therefore the objectives of the present study were to examine if
morphologically identified species are genetically differentiated; to investigate the occurrence of hybridization between taxa;
and to quantify genetic diversity and its distribution to identify areas of value for conservation. Samples from the seven
yellow-flowered Ortgiesia were collected in 26 populations throughout the entire geographical distribution of the species.
Two plastid regions (rpl32-trnL and rps16-trnK ? cpDNA) and the nuclear gene phyC were sequenced for 204 and 179 individuals,
respectively. Thirty-two haplotypes were found for all seven Ortgiesia using cpDNA, of which three were shared among species.
This haplotype sharing was not geographically structured. Only one possible ancient hybridization event was detected by our cpDNA
analyses, which involved A. comata and A. caudata. Less genetic structure was observed with phyC, with 11 out of 54 haplotypes
shared among all the seven Ortgiesia. Considering all the populations sampled, the highest number of haplotypes were found at
latitudes of ~27° S, the northeast region of the Brazilian state of Santa Catarina, for both cpDNA and phyC data. Our results
suggest that the haplotype sharing found for the seven yellow-flowered Ortgiesia is probable due to the persistence of ancestral
polymorphism. However, localized hybridization events may also have occurred during the diversification of the group. The results
found in this study, together with morphological and ecological data, support the contention that five of these species are
distinct lineages (A. blumenavii, A. calyculata, A. caudata, A. kleinii, and A. winkleri). Aechmea comata and A.kertesziae did not
present clear genetic boundaries and also do not present clear morphological characters or ecological data that can be used to
differentiate them. Therefore more studies involving these species are needed to identify if hybridization between them is going on,
as individuals with intermediate morphology are observed, or if they represent only one taxon. The northeast region of Santa
Catarina state (latitude of ~27° S) was identified as harboring the highest levels of genetic diversity, and thus is of
conservation value for yellow-flowered Ortgiesia.

Keywords:—cpDNA; Haplotype Network; phyC.