Multilocus phylogenetic analysis of Colletotrichum gloeosporioidescausing anthracnose disease of Murraya koenigiiin India

Curry leaf, also known as sweet neem (Murraya koenigii), is a vital medicinal plant thriving in tropical and subtropical climates worldwide. It holds a significant position in India as both an ornamental and therapeutic crop. Curry leaves, whether used fresh, in dried leaf powder form, or for essential oil preparation, are commonly incorporated into soups and various dishes throughout the seasons. However, despite its widespread commercial, industrial, and medical applications, this crop remains highly susceptible to diverse biotic and abiotic stresses. Additionally, these leaves find applications in nutraceuticals, medicine, therapy, and various industrial uses. However, a significant challenge to curry trees is anthracnose, a leaf spot disease that renders the leaves unsuitable for consumption. In this study, curry leaves exhibiting anthracnose symptoms were gathered from four locations in the Coorg region of Karnataka, India. The responsible fungus (Colletotrichumsp.) was isolated and subjected to molecular identification and genetic diversity analysis. Identification of the fungus was based on micro-morphological and cultural characteristics, as well as multilocus analysis (utilizing ITS, SSU, and LSU sequences). Among the forty isolates obtained, four were selected for analysis. These four isolates displayed a nucleotide identity of over 98% with known Colletotrichum gloeosporioidesisolates, confirming that the fungus responsible for infecting curry leaves is indeed Colletotrichum gloeosporioides. Phylogenetic analysis further supported this finding, showing that all four Colletotrichumisolates from curry leaves were closely related to C. gloeosporioidesisolates that infect mango trees.