LAUSR

Hylocereus undulatus Britt (pitaya) is a tropical fruit that has been commonly cultivated in Guizhou Province, China, in recent years due to its good taste and high nutritional value. This planting area currently ranks third in China. Viral diseases have increasingly emerged in pitaya cultivation because of the expansion of the pitaya planting area and the characteristics of vegetative propagation. The spread of pitaya virus X (PiVX; a Potexvirus) is among the most severe viruses threatening the quality and yield of pitaya fruit. In order to investigate the occurrence of PiVX in pitaya cultivations in Guizhou Province, we developed a reverse transcription loop-mediated isothermal amplification (RT-LAMP) method that can detect PiVX with high sensitivity and specificity, at a low cost and producing a visualized result. The RT-LAMP system was significantly more sensitive than RT-PCR, and was highly specific to PiVX. Furthermore, PiVX coat protein (CP) can form a homodimer and PiVX may use its CP as a plant RNA silencing suppressor to enhance infection. To the best of our knowledge, this is the first report of rapid detection of PiVX and functional exploration of CP in a Potexvirus. These findings will provide opportunity for early diagnosis and prevention of viruses in pitaya.