Using phylogenetics to understand the evolutionary relationships of <i>Hibiscus</i> section <i>Furcaria</i>

Neopolyploids constitute at least 35% of known species of angiosperms, and because polyploidization is a pertinent process in plant diversification and domestication, it is a thriving field of study. Hibiscus section Furcaria includes several groups of polyploids in addition to ten known diploid species. In previous studies genome groups for Hibiscus section Furcaria were determined through artificial hybridization experiments and patterns of biogeography were elucidated based on the distribution of diploids and polyploids. For instance, the Australian hexaploids contain 3 genomes (designated G, J, and V) and are thought to have developed from a polyploidization event between an African diploid relative (G) and two unknown donors (J and V). This study seeks to perform phylogenetic analysis using a suite of chloroplast and nuclear regions to determine the maternal genetic relationships between the diploids and the Australian hexaploid lineage, and to reconstruct the origin of this group in order to determine if any surviving diploid donors exist related to the unknown J and V genomes. Four chloroplast regions and two nuclear regions were explored to determine genome relationships. Results showed the Australian hexaploid species form a well-supported clade using chloroplast genes (ndhC-trnV,ndhF-rpl32R,rpl32F-trnL,rps16-trnK) and ITS with Hibiscus sudanensis as the maternal donor of the G genome group. Possible donors to the J and V genome groups are proposed based on the phylogenies, morphology, and biogeography but more sampling of clones is needed to ensure the identity of possible donors lineages.