Diversity and distribution of Lophodermium species on non‑native Pinus species in the Southern Hemisphere

Abstract

Lophodermium species are amongst the most commonly isolated endophytic fungi on the needles and cones of pines. Of the 38 species reported on these trees, only Lophodermium seditiosum is considered a major pathogen. Species of Pinus have been widely established as non-natives in Southern Hemisphere countries, and several Lophodermium species have been reported on the needles of these trees. However, most of these reports are based on morphology alone. In this study, we considered the biogeography of Lophodermium species across the Southern Hemisphere by obtaining and identifying isolates from non-native Pinus species planted in Australia, Chile, Colombia, New Zealand, and South Africa. A multi-locus phylogenetic approach was used to delineate the species, and characteristic morphological features were evaluated against the resulting phylogeny. Phylogenetic analyses revealed the presence of five Lophodermium taxa on Pinus species in the Southern Hemisphere. A species belonging to the L. conigenum-australe complex was found in all countries except Chile. Lophodermium indianum and L. molitoris were found only in Colombian and New Zealand collections, respectively. Two distinct lineages of L. pinastri emerged from Chile, New Zealand, and Australia. None of the morphological features could distinguish between the different taxa of Lophodermium found, with several of the traits varying by host or location. Overall, the results support the fact that various cryptic Lophodermium species occur on the sampled Pinus species and suggest that several independent introductions of these fungi have occurred in Southern Hemisphere countries.