First Report and Yield Reduction of Emerging Yellow Spot Disease on Melon (Cucumis melo) Caused by Melon Yellow Spot Virus (MYSV) in Indonesia

Typical symptoms of melon yellow spot disease include leaf curling, mosaic, chlorotic spots, fruit discoloration, and cracking, which are constantly found in melon greenhouses in Indonesia. These symptoms lead to considerable losses, reducing fruit weight by up to 66.67% and lowering the Brix score, making the fruit unmarketable. RT-PCR targeting the N-gene of MYSV showed all samples were positively infected. Bioinformatics analysis revealed that Asian isolates of MYSV are highly identical and share a common ancestor, highlighting MYSV as an emerging disease to melon production across Asia.