Phylogenetic relationships, hybridization events, and drivers of diversification of East Asian wild grapes as revealed by phylogenomic analyses

East Asian wild grapes show a high level of species diversity and have been widely recognized as important germplasm resources of wine, table grapes, and resistance to biotic and abiotic stresses for the grape industry. However, the deeper phylogenetic relationships and drivers of diversification of East Asian Vitis remain poorly understood. Hybridization and introgression events of East Asian Vitis are not well investigated, particularly at the genome-wide scale. The phylogenetic relationships of East Asian Vitis are herein explored using nuclear and plastid genome data based on target enrichment (Hyb-Seq). Seven major clades are recognized for East Asian Vitis based on the nuclear phylogenetic trees, but there is topological incongruence between concatenated and coalescent analyses. Furthermore, significant cytonuclear discordance is observed within East Asian Vitis. Species network analyses identified several hybridization events within East Asian Vitis. These interspecific hybridization events may have caused the topological discordances and relatively low support detected in our analyses. Ecological niche modeling shows that most of the diversification of East Asian Vitis species is driven by temperature and precipitation environmental variables. Sympatric parallel diversifications of major clades also may have facilitated the rich diversity in East Asian Vitis.

Automated summary

East Asian wild grapes, with their high species diversity, are recognized as important germplasm resources for the grape industry. However, the phylogenetic relationships and drivers of diversification of East Asian Vitis need further understanding. This study uses nuclear and plastid genome data to explore the phylogenetic relationships of East Asian Vitis and identifies hybridization events and ecological drivers of diversification.