First report of Penicilliopsis clavariiformis causing seed rot in Diospyros crumenata based on morphological, pathological and molecular assessment

Abstract

Diospyros crumenata Thw. is an edible and economically vital critically endangered evergreen tree native to the Western Ghats of India and Sri Lanka. This study investigates the fungal pathogen Penicilliopsis clavariiformis, which has been found for the first time to cause significant seed damage in D. crumenata with a 40% seed rot disease incidence that severely impacts seed germination, characterised through molecular phylogenetic analysis of concatenated sequences of the ITS and tub2 genes, combined with cultural and morphological features. Pathogenicity tests conducted both in vivo and in vitro, together with the re-isolation and identification of the pathogen based on Koch's postulates, verified its pathogenic nature. To our knowledge, this is the first report of P. clavariiformis causing seed rot to D. crumenata both in India and globally. This discovery emphasizes the urgent need for a holistic approach for seed disease management to safeguard D. crumenata, which plays a vital role in local ecosystems due to its high timber and nutritional fruit value.