Aoki-Gonçalves et al. 2015 (Conference Paper) Tillandsia

Genetic structure and diversity patterns of Tillandsia aeranthos (Lois.) L.B. Smith in Brazil

Author(s):—Felipe Aoki-Gonçalves, Thais Guimarães & Clarisse Palma-Silva 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:—Brazil is the diversity center of Bromeliaceae. Such an area with high levels of species richness and endemismis considered to be an ideal site for speciation. Tillandsia aeranthos is epiphytic and in Brazil it occurs mainly in the state of Rio Grande do Sul, which presents very distinctive topographic profiles. Objectives: 1) test cross-amplification of microsatellite markers developed for other bromeliads in T. aeranthos; 2) quantify genetic diversity of T. aeranthos populations; 3) evaluate genetic structure of T. aeranthos natural populations through different topographies in southern Brazil. Leaf samples from 8 populations (87 individuals) were collected and total DNA was extracted. Ten nuclear and four plastidial microsatellite markers were tested, genotyped and analyzed. Levels of genetic diversity were described through: number of alleles per locus, observed heterozygosity (Ho) and expected heterozygosity (He). Deviations from the Hardy-WeinbergEquilibrium were calculated through the inbreeding coefficient (FIS). Levels of genetic structure of analyzed populations were estimated using the Analysis of Molecular Variance (AMOVA). The fixation index FST wasused as a genetic differentiation parameter between populations. The hypothesis of isolation-by-distance by comparing geographic and genetic distances among populations was also tested. Seven nuclear loci amplified satisfactorily and were polymorphic. All plastidial markers amplified satisfactorily and one was polymorphic.Per population, the number of alleles ranged from 39 to 59; the mean He value was 0.844 and the mean Ho value was 0.703. The mean value of FIS was 0.179 (all FIS values were significant - p<0.05). The mean FST value was 0.032 and highly significant (p-val = 0.0003). The isolation-by-distance test did not show correlation. These results suggest low yet significant levels of genetic structure, which indicates effective
gene flow throughout the analyzed area, despite the topographic differences along it.

Keywords:—Bromeliaceae; Phylogeography; Microsatellites.