Occurrence of a Hop stunt viroid (HSVd) variant in yellow corky vein disease of citrus in India.
A viroid was isolated and purified from total nucleic acid extract of Kagzi lime (Citrus aurantifolia [Citrus aurantiifolia]) leaves affected by yellow corky vein disease. It was cloned in pGEMT-easy vector system and sequenced. In silico analysis showed that it consisted of 295 nucleotides. In BLAST analysis the sequence aligned with different hop stunt viroid (HSVd) variants showing nearly 100% sequence identity with 6 citrus cachexia isolates of HSVd. The viroid was tentatively named as yellow corky vein variant of HSVd (HSVd-ycv). This constitutes the first report of molecular evidence for occurrence of a HSVd variant from citrus in India.