First report of Colletotrichum gloeosporioides causing severe anthracnose on Litsea deccanensis seedlings in India

Abstract

Litsea deccanensis, commonly known as Jiggat, finds commercial use in India for the production of agarbatti or incense sticks, with its stem bark serving as a crucial raw material. The plant seedlings are important for conservation efforts, biodiversity, and potential uses in medicine, horticulture, and research. Within the campus nursery of the Institute, distinct signs of anthracnose were observed in the seedlings of L. deccanensis. The incidence of this disease was documented at 50 % among the hundred assessed seedlings maintained in the KFRI nursery. Through rigorous isolation, purification, and analysis, the responsible pathogen was identified as Colletotrichum sp. Phylogenetic analysis of concatenated sequence alignment of Internal Transcribed Spacer (ITS) region, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and beta-tubulin (TUB2) genes supported by cultural morphological characteristics revealed Colletotrichum gloeosporioides as causal agent. To affirm the pathogenic nature of the fungus, pathogenicity tests were conducted, both in controlled environments and within the living plant, supported by subsequent re-isolation and identification of the pathogen, in accordance with Koch's postulates. To the best of our knowledge, this is the first report of anthracnose caused by C. gloeosporioides on Litsea deccanensis in India.