Characterization of Neopestalotiopsis clavispora: A novel pathogen causing leaf spot on Pandanus amaryllifolius in India

Pandanus amaryllifolius, commonly known as the fragrant screw pine, is a highly valued aromatic plant in the Pandanaceae family. In May 2022, an increased severity of leaf spot was observed on P. amaryllifolius at the University of Agricultural Sciences, GKVK, Bangalore, and surrounding areas. Infected leaves exhibited nearly circular to irregular brown spots with reddish-brown margins and a yellow halo, gradually leading to blighting of leaves. The associated fungus was isolated and identified as Neopestalotiopsis clavispora through micro-morphological characterization and multigene phylogenetic analysis comprising Internal transcribed spacer (ITS) region of rDNA and β-tubulin (TUB2). Biological characterisation involved evaluation of the influence of solid media, varying temperatures and pH levels on the growth and sporulation of the pathogen. N. clavispora infecting P. amaryllifolius was identified to be growing ideally on oat meal agar (OMA) medium at 30°C and pH 6. These findings provide significant insights into the emergence of N. clavispora as a novel fungal pathogen affecting P. amaryllifolius in India and contribute to developing effective management strategies.