Abstract
The grapevine leaf rust fungus, Phakopsora ampelopsidis species complex, is now segregated into three distinct species, P. ampelopsidis, P. euvitis and P. vitis, based on host specificity, life cycle and morphology. Similarities in the spore morphology and host relationships of the three Phakopsora species suggest their close phylogenetic relationships. To determine their possible phylogeny, ITS1 and ITS2 regions including 5.8S gene of small subunit rDNA were amplified by a PCR method, sequenced and generated phylogenetic trees using parsimony and neighbor-joining methods. However, the ambiguous sequences were found in the ITS1 region, which made definite alignment impossible. Therefore, neighbor joining and parsimony trees were constructed using the nucleotide sequence data of the 5.8S rRNA gene and ITS2 region. The reconstructed phylogeny showed that the three species formed distinct clades with a hypothetical common ancestor and separated from the two species of soybean rusts, P. pachyrhizi and P. meibomiae. The results also indicated possible existence of a cryptic species, which may also be parasitic on grapevines.
