First report of Lasiodiplodia iraniensis causing leaf spot disease of Eucalyptus in India

Eucalyptus species are highly valuable source for wood-based paper and pulp industries in India and worldwide. Therefore, accurate identification of pathogens affecting Eucalyptus is of critical importance. In March 2022, symptoms of a leaf spot disease were observed in Eucalyptus plantations in northern India. Morphological characteristics coupled with phylogenetic analysis of combined internal transcribed spacer (ITS), partial translation elongation factor-1α (tef1), and partial β-tubulin (tub2) regions identified the associated species as Lasiodiplodia iraniensis. The pathogenicity of L. iraniensis was confirmed on detached Eucalyptus leaves and reconfirmed in glasshouse inoculation experiments. Finally, re-isolation of the pathogen from the inoculated leaves fulfilled the Koch's postulates. This study is the first report of pathogenic L. iraniensis on Eucalyptus in India. Further studies on the diversity of this pathogen and identification of disease resistant Eucalyptus germplasm are required. [Display omitted] •This study first time reports Lasiodiplodia iraniensis as a foliar pathogen of Eucalyptus in India.•The pathogen was identified based on microscopic features, DNA sequence analysis, and pathogenicity tests.•This is a new taxonomic addition to the diversity of Lasiodiplodia fungi in India.•This study provides future directions to decipher the diversity of Lasiodiplodiaspecies and testing of Eucalyptus genotypes for disease resistance.