Occurrence and Distribution of Major Viruses Infecting Passion Fruit in Guizhou Province, China, and Molecular Characterization of Two Potyviruses

The planting of passion fruit (Passiflora edulis) in Guizhou Province has gradually increased, and the area under cultivation ranks third in China. However, the cultivation and production of passion fruit is severely affected by viral diseases. In 2021 and 2022, we investigated the occurrence of multiple viral diseases in major cultivation areas, identified the main viruses and conducted field surveys in different growing areas of passion fruit in Guizhou Province, China. In total, 308 samples were randomly collected from 10 different passion fruit cultivation areas, and seven viral diseases were identified using electron microscopy, small RNA sequencing, and reverse-transcription polymerase chain reaction. Among them, the infection rate of Telosma mosaic virus (TeMV) was the highest (50%), followed by East Asian Passiflora virus (EAPV) (19%), and cucumber mosaic virus (CMV) (15%). The detection rates of the other four viruses were lower: Passiflora latent virus (PLV) (1%), turnip mosaic virus (TuMV) (0.6%), Passiflora virus Y (PaVY) (0.3%), and Euphorbia leaf curl virus (ELCV) (6%). In addition, high rates of mixed TeMV + CMV + EAPV infections were found in the province. Notably, 79% of EAPV-infected plants were also infected with TeMV. Finally, the molecular characteristics of the two highly detected potyviruses, TeMV and EAPV, were analyzed. To our knowledge, this study is the first systematic survey of viral diseases of passion fruit in Guizhou Province, China.