Abstract:
During 2015, a new basal rot disease was observed on potted plants of Strelitzia reginae in an ornamental
nursery located in eastern Sicily. Isolations from symptomatic parts of these diseased plants consistently yielded
cylindrocarpon-like isolates. Multigene analyses of the partial gene regions of 28S large subunit nrDNA, β-tubulin,
histone H3, translation elongation factor 1-alpha, internal transcribed spacer region and intervening 5.8S nrRNA
gene, and RNA polymerase II second largest subunit genes, supported by morphological characters supported the
recognition of a new genus, Pleiocarpon based on P. strelitziae sp. nov., and a new Ilyonectria species, described
here as I. strelitziae sp. nov. The pathogenicity of both I. strelitziae and P. strelitziae were confirmed on young
plants cultivated under controlled conditions in a growth chamber. Both cylindrocarpon-like fungi were pathogenic
to S. reginae and reproduced symptoms similar to those observed in the nursery. Of the two species, P. strelitziae
was more aggressive than I. strelitziae, resulting in the death of all inoculated plants.
