Is self-incompatibility a reproductive barrier for hybridization in a sympatric species?
Linda M Martínez-RamosSonia Vázquez-SantanaJosé G García-FrancoMaría C MandujanoPublished in: American journal of botany (2024)
Opuntia cantabrigiensis had a strong pollen-pistil barrier, likely due to its self-incompatibility. Opuntia robusta, the dioecious species, is an obligate outcrosser and probably partially lost its ability to prevent interspecific pollen germination. Given that the self-compatible species can set hybrid seeds, we conclude that pollen-pistil interaction and high flowering synchrony represent weak barriers; whether reproductive isolation occurs later in their life cycle (e.g., germination or seedling survival) needs to be determined.