An Analysis of Factors Contributing to Hybrid Zone Expansion in the Piriqueta Caroliniana Complex

University Of Tennessee Knoxville, Knoxville TN

Investigators

Abstract

The proposed research will examine the processes contributing to the spread of novel genotypes resulting from hybridization between morphologically and ecologically distinct lineages of the Florida rock rose (Piriqueta caroliniana). The mixing of divergent taxa via natural hybridization is considered to have been important in the history of a variety of plants and animals. However, we currently have little information on the dynamics of hybrid zones that extend over broad geographic regions. The process of spread of hybrid genotypes and expansion of the hybrid zone will be complicated by hybrid breakdown (loss of viability and fertility) in the early generations following hybridization. This research will examine patterns of hybrid breakdown and its demographic and genetic consequences. Patterns of fitness loss that accompanies hybridization will be documented and its impact on the process of hybrid zone expansion will be assessed. Results from this study will provide information on processes that affect aspects of natural hybridization that have direct economic and social impacts including; 1) the spread of exotic species that is facilitated by hybridization with natives, and 2) the escape of genes from genetically modified crops via hybridization with native and weedy species. Furthermore, information obtained on the development of superior genotypes through natural processes may have applications in plant and animal breeding programs.