Fusarium wilt of bottle gourd (Lagenaria siceraria) caused by Fusarium oxysporum at high altitude region of Ladakh

Abstract: Ladakh, a trans-Himalayan cold arid region characterized by sub-zero temperatures and lower atmospheric pressure, limits the cultivation period of crops to the summer months. Bottle gourd, a nutrient-rich Cucurbitaceae vegetable, is grown from April to September in Ladakh. However, the favorable environmental conditions for fungal plant pathogens challenge bottle gourd cultivation during this period. During a field survey of the Muth region located at an elevation of 4221 m above sea level, wilting of bottle gourd leaves was observed in August, with a disease incidence of 14% and a severity index of 5%. Isolation and characterization of the pathogen on potato dextrose agar (PDA) medium identified it as Fusarium sp., with typical spores observed under the microscope. The pathogenicity test confirmed the pathogenic nature of the isolate. Amplification and sequencing of the ITS region showed high similarity with Fusarium oxysporum in the UNITE database, and the sequence has been submitted to NCBI GenBank under the accession number OP453355. These findings provide valuable insights into the potential threats of fungal pathogens to bottle gourd cultivation in Ladakh and highlight the importance of disease management strategies in high-altitude regions.