Distribution of citrus viroids and Apple stem grooving virus on citrus trees in Japan using multiplex reverse transcription polymerase chain reaction

The distribution of citrus viroids – Citrus exocortis viroid (CEVd), Citrus bent leaf viroid (CBLVd), Citrus viroid (CVd)-I-LSS, Hop stunt viroid (HSVd), Citrus viroid III (CVd-III), Citrus viroid IV (CVd-IV), and Citrus viroid OS (CVd-OS) – and Apple stem grooving virus (ASGV; synonym: Citrus tatter leaf virus) were investigated using the multiplex reverse transcription polymerase chain reaction on samples from 217 citrus trees in Japan. HSVd and CVd-III were the first and second most frequently detected, respectively. CVd-I-LSS and CVd-OS were also frequently detected from some species or varieties, whereas CEVd, CBLVd, CVd-IV, and ASGV were detected only occasionally.