Taxonomic identity of a Phakopsora fungus causing the grapevine leaf rust disease in Southeast Asia and Australasia

• Three or more Phakopsora fungi cause grapevine leaf rust (GLR) in Asia and Australasia.
• A GLR fungus in Southeast Asia and Australasia is morphologically similar to two East Asian GLR fungi.
• The three fungi are separable by the internal transcribed spacer 2 and large-subunit rRNA gene sequence differences.

Three distinct groups were revealed among the grapevine leaf rust fungi from Japan, Taiwan, Thailand, Malaysia, Indonesia, East Timor and Australia in phylograms generated from sequence analyses of the internal transcribed spacer 2 and the large-subunit rRNA gene (D1/D2 region). A group of Thai, Malaysian-Indonesian and East Timorese-Australian fungi was distinct from two other groups of grapevine leaf rust fungi, Phakopsora meliosmae-myrianthae and P. montana, distributed in temperate East Asia. Although complete life cycle and native host plants are unknown for the Southeast Asian and Australasian fungus, it is likely to be a biologically distinct species.