Pollen-pistil interaction as a barrier to reproductive isolation between Pitcairnia staminea and P. albiflos (Bromeliaceae).

• Grant number: 24/21993-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2025
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Botany
• Principal Investigator: Clarisse Palma da Silva
• Grantee: Henrique Vilela da Mata Bianchini
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 21/10639-5 - Center for Research on Biodiversity Dynamics and Climate Change, AP.CEPID

Abstract

Lineages with gene flow and recent divergence are excellent models for studying the evolution of reproductive barriers between populations and species, as they allow for the observation of hybrid formation and allele introgression. Bromeliads of the genus Pitcairnia have been used as a model for speciation studies involving gene flow. Pitcairnia albiflos and P. staminea are sister species, endemic to inselbergs in Rio de Janeiro and Niterói, which hybridize in sympatry despite strong pre- and post-zygotic reproductive barriers reported in previous studies by our research group. However, post-pollination pre-zygotic reproductive barriers have not yet been studied in this model. In this project, we will investigate how post-pollination reproductive barriers promote reproductive isolation between Pitcairnia albiflos and Pitcairnia staminea by: 1) assessing the pollen viability of parental species and hybrids in sympatric and allopatric populations; and 2) analyzing pollen tube growth through crosses between the parental species and hybrids. We hope this study will enhance our understanding of the various barriers contributing to reproductive isolation in this model of speciation with gene flow and hybridization.