Hybridization between two sister species of Bromeliaceae:Vriesea carinataandV. incurvata

Abstract

Studies on interspecific gene flow and hybridization are important for understanding speciation processes and the movement of genes across species boundaries. In sympatric areas, hybridization between closely related species can be a common phenomenon and the degree of reproductive isolation (RI) among these species is closely related to the probability of hybrid formation. Here, using 14 nuclear microsatellites and two plastid DNA regions, we investigated the occurrence of natural hybridization in four sympatric populations of Vriesea carinata and V. incurvata. We also analysed four allopatric populations (two from each species), totalling 272 samples. These species share pollinators and have sequential flowering with a short period of overlap. Based on genetic assignment tests, 17 hybrids were detected in two of the four sympatric populations studied (8.29% of the individuals sampled). Our results showed low levels of nuclear (F ST = 0.098) and high plastid genetic differentiation (F ST = 0.601), with no haplotype sharing between parental species. The presence of plastid DNA haplotypes of both parental species in the hybrids indicated that hybridization probably occurred in both directions. We identified few hybrids, probably in consequence of some degree of RI between these species. Several RI barriers may be acting to maintain species integrity, temporal flowering differences being one important factor.

Advances in and perspectives on evolution in Bromeliaceae

“…Lexer et al (2016) expanded their previous studies on Alcantarea, a terrestrial bromeliad genus adapted to inselbergs in the Atlantic rainforest and savanna-like campo rupestre habitats of southeastern Brazil (Barbar a et al, 2007(Barbar a et al, , 2008Versieux et al, 2012). There was limited haplotype sharing among species, a pattern also observed by Zanella et al (2016) for Vriesea spp. evaluated with nuclear and plastid DNA markers.…”

“…In this new study, they included populations of five narrow distributed Alcantarea spp. Zanella et al (2016) studied natural hybridization in four sympatric populations of the sister species Vriesea carinata Wawra and V. incurvata Gaudich. Their results indicated possible interspecific gene flow among the studied species.…”

Drivers of bromeliad leaf and floral bract variation across a latitudinal gradient in the Atlantic Forest

“…On the other hand, the V. incurvata and V. taritubensis varieties showed moderate to high intraspecific genetic diversity and intraspecific gene flow (Table 1; Tables S1 and S3, Figure S2, Appendix S2), as has been observed for other bromeliad species (Goetze, Zanella, Palma-Silva, Büttow, & Bered, 2017;Palma-Silva et al, 2009;Zanella et al, 2016). The low genetic variation among localities within taxa suggests that intra-taxon gene flow has been maintained ( Figure S2, Appendix S2).…”

“…We used plastidial data (trnL-trnF and matK) from V. incurvata sequenced by Zanella, Palma-Silva, Goetze, and Bered (2016) and from 40 new samples of V. taritubensis (Table S1, Appendix S2). Among the 15 localities, we have morphological data for nine of them.…”

“…For details about DNA processing and PCR conditions see Zanella et al (2016). We performed multiple sequence alignment in MUSCLE (Edgar, 2004), implemented in MEGA 7.0 (Kumar, Stecher, & Tamura, 2016).…”