Paramicrosphaeropsis eriobotryae sp. nov., a new agent of loquat canker in Iran

Abstract

Loquat (Eriobotrya japonica) is a subtropical evergreen plant, important in terms of both horticulture and green space in the urban environment. In recent years, symptoms of branch and trunk canker, dieback and decline have been observed in the main cultivation areas of this tree in Iran. To study the aetiology of loquat canker in Fars Province, branches and trunks of loquat trees with disease symptoms were sampled from 2018 to 2019. Several isolates of an unknown Paramicrosphaeropsis species (Didymellaceae, Pleosporales, Dothideomycetes) were recovered from the trunks and branches of infected loquat trees. Phylogenetic analysis of the isolates based on a multigene phylogeny of the ribosomal internal transcribed spacer (ITS), partial β‐tubulin gene (tub2) and the second‐largest subunit of RNA polymerase II (rpb2) loci revealed that the isolates belonged to a new taxon, Paramicrosphaeropsis eriobotryae sp. nov. Pathogenicity tests revealed that this species was able to cause canker, trunk flaking, dieback, decline, leaf yellowing, defoliation and growth reduction in loquat trees. A host range evaluation on detached branches of some important horticultural trees occurring adjacent to loquat tree orchards of Fars Province showed that P. eriobotryae might have a broader host range, as it was also able to infect almond and olive trees.