Phylogenetic relationships of Australian and New Zealand Armillaria species

Abstract

Armillaria species cause Armillaria root rot on a wide range of plant species throughout the world. Based on morphology and sexual compatibility, various species of Armillaria have been reported from Australia and New Zealand. These include A. hinnulea, A. fumosa, A. pallidula, A. novae-zelandiae and A. luteobubalina from Australia. In New Zealand, A. limonea, A. novae-zelandiae, A. hinnulea and a fourth undescribed but morphologically distinct species are recognized. To determine the phylogenetic relationships between Armillaria spp. from Australia and New Zealand, the ITS region (ITS 1, 5.8S rRNA gene and ITS2) of the rRNA operon was amplified and the DNA sequences determined for a collection of isolates. The ITS sequences of A. ostoyae (from USA) and A. sinapina (from USA) were included for comparison. Phylogenetic trees were generated using parsimony analysis. Armillaria hinnulea was found to be more closely related to Armillaria spp. occurring in the Northern Hemisphere than it was to the other Australian and New Zealand species. The remainder of the Australian and New Zealand Armillaria spp. included in this study formed a monophyletic clade and confirmed separation of species based on morphology and sexual compatibility.