New record of natural occurrence of carrot thin leaf virus (CTLV) on carrot (Daucus carota L.) from India

During 2020–2021, carrot plants with mild yellow mottling, little leaf and leaf curl symptoms at Experimental field of Division of Vegetable Sciences, IARI, New Delhi were observed. Electron microscopy of negatively stained leaf dip preparation showed flexuous filamentous particles measuring 750 × 12 nm. Samples were subjected to DAC-ELISA and ISEM tests using polyclonal antibodies of PVY, PVX and FLMV (football lily mosaic virus). Out of 24 samples, symptomatic 5 samples reacted positive with polyclonal antibodies to PVY in DAC-ELISA and ISEM test but not with PVX and FLMV. To further confirm the presence of PVY, total RNA was extracted from symptomatic and non symptomatic samples and RT-PCR assay was performed using potyvirus coat protein (CP) region group specific degenerate primer and an amplicon of 750 bp was seen in the symptomatic samples. RT-PCR product was cloned in pGEMT Easy vector and the CP sequence analysis revealed 100% identity with carrot thin leaf virus (CTLV). This is the first report of CTLV on a new host, Daucus carota.