Korean Journal of Agricultural Science ISSN:2466-2402(Print) 2466-2410(Online) 농업과학연구

To follow up on a 2017 survey of tomato virus diseases, samples with virus-like symptoms were collected from the same areas (Buyeo-gun, Chungchungnam-Do and Daejeon, Korea) in 2018. While in 2017 mixed infections of Tomato mosaic virus with either Tomato yellow leaf curl virus (TYLCV) or Tomato chlorosis virus were detected, only TYLCV was detected in symptomatic samples in 2018. TYLCV amplicons of c.777 bp representing the coat protein (CP) coding region were cloned from the TYLCV positive samples, and the sequence data showed a 97.17% to 98.84% nucleotide and 98.45% to 99.22% amino acid identity with the 2017 Buyeo-gun isolate (MG787542), which had the highest amino acid (aa) sequence identity of up to 99.2% with four 2018 Buyeo-gun sequences (MK521830, MK521833, MK521834, and MK521835). The lowest aa sequence identity of 98.45% was found in a 2018 Daejeon isolate (MK521836); the distance between Buyeo-gun and Daejeon is about 45 km. Phylogenetic analysis indicated that the currently reported CP sequences are most closely related to Korean sequences from Masan (HM130912), Goseong (JN680149), Busan (GQ141873), Boseong (GU325634), and the 2017 isolate TYLCV-N (MG787543) in the ‘Japan’ cluster of TYLCV isolates and distinct from the ‘China’ cluster isolates from Nonsan (GU325632), Jeonju (HM130913) and Jeju (GU325633, HM130914). Our survey data from 2017 and 2018 suggest that TYLCV has become established in Korea and may be spread by whitefly vectors from weed reservoirs within the farm environment.