PHYLOGENETIC RELATIONSHIPS IN ACTINIDIA AS REVEALED BY NUCLEAR DNA GENETIC MARKERS AND CYTOPLASMIC DNA SEQUENCE ANALYSIS

Phylogenetic relationships between Actinidia taxa were investigated using AFLP markers and cytoplasmic DNA sequences. 105 reliable AFLP markers were amplified across all samples by 4 selective AFLP primer pairs, of which 103 were polymorphic within Actinidia, revealing 98% of polymorphic markers in the genus and 27% of mean polymorphic markers within taxa. Intraspecific ploymorphisms were also found within several taxa by cpDNA and mtDNA sequence analysis. Genetic relationships shown by clustering analysis based on AFLP markers are generally consistent with those by traditional classification based on morphology, but none of the genome (nuclear DNA AFLP makers, cpDNA and mtDNA sequences) phylogenies supports monophyly of any of the four current sections in Actinidia. The results support reticulate evolution, hybridization/introgression events and multiple origins of some polyploid taxa in the evolution of Actinidia. Clustering taxa by geographic distribution suggests that this has played an important role in speciation. The intrageneric subdivision of Actinidia should be revised.