Chrysoporthe puriensis sp. nov. from Tibouchina spp. in Brazil: an emerging threat to Eucalyptus

Abstract

The discovery of Cryphonectriaceae and more specifically species related to the Eucalyptus canker pathogen Chrysoporthe cubensis on shrubs and trees in the Melastomataceae, has deepened our understanding of relevant, and potentially globally threatening tree pathogens. Recent isolations of Cryphonectriaceae associated with cankers on Tibouchina spp. in Brazil gave rise to an apparently undescribed species of Chrysoporthe associated with stem and branch cankers that lead to tree death. Cultures of this fungus were subjected to phylogenetic studies based on sequences for the ITS and β-tubulin gene regions. These analyses revealed a novel taxon that is described here as Chrysoporthe puriensis sp. nov., having both sexual and asexual states. Pathogenicity tests on two species of Tibouchina (T. granulosa, T. heteromalla) and hybrids of Eucalyptus grandis x E. urophylla showed that Chr. puriensis can infect and cause disease on all of these trees. It is clearly not only damaging on native Tibouchina spp. where environmental conditions are conducive to disease development, but also potentially threatening to non-native Eucalyptus spp., which form the basis of a major plantation forest industry.

Chrysoporthe puriensis causing canker and mortality in Pleroma mutabile in the Atlantic Forest, Brazil

“…The symptoms observed in the study were canker and consequent death of trees that were found in both urban afforestation and native forests. Chrysoporthe puriensis , described for the first time in Brazil by Oliveira et al (2021), has been observed in P. heteromallum , P. candolleanum , and P. granulosum in the states of Bahia, Minas Gerais, and Rio de Janeiro. Studies on the species of Melastomataceae and Myrtaceae in Brazil in recent years have been motivated by the diversity of species and genera of the Cryphonectriaceae family occurring in Latin America (Crous et al, 2015; Ferreira et al, 2019; Gryzenhout et al, 2005, 2009; Oliveira et al, 2021, 2022; Soares et al, 2018).…”

“…Conidiogeneous cells phialidic, apical or lateral 8.0-17.5 μm long. Conidia 3.0-5.5 x 1.5-2.5 μm, were hyaline, aseptate and oblong to cylindrical accordingly described byOliveira et al (2021).…”

IMA genome - F14

“…Chrysoporthe puriensis was first reported causing a stem canker disease on Tibouchina spp. in Brazil (Oliveira et al 2021). Pathogenicity tests showed that C. puriensis is pathogenic on the hybrid Eucalyptus grandis × E. urophylla, suggesting that the fungus could threaten commercially-grown Eucalyptus plantations in South America (Oliveira et al 2021).…”

New Melastomataceae hosts of Chrysoporthe species in Brazil

“…L'Hér, and Melastomataceae A. Juss. Chrysoporthe species have brown to black‐fuscous fruiting bodies which are semi‐immersed in the bark of the host, causing lesions, branch dryness, typical cankers, and even plant death (Chen et al, 2010; Chungu et al, 2009; Gryzenhout et al, 2004; Gryzenhout et al, 2005; Gryzenhout et al, 2009; Oliveira et al, 2021; Sharma et al, 1985; Soares et al, 2018).…”

“…These species are morphologically similar, distinguishable based on subtle differences in spore size and optimal growth temperature (Gryzenhout et al, 2009). Accurate identification is possible with molecular analysis, especially based on the β‐tubulin gene (Gryzenhout et al, 2006, 2009; Oliveira et al, 2021).…”