• Research in Plant Disease
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• v.25 no.4
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• pp.233-236
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• 2019

Citrus vein enation virus (CVEV), which was regulated as a quarantine virus in Korea, was firstly found on Jeju Island in 2017. In February 2018, a survey was carried out to determine the distribution of CVEV in the main commercial areas growing Citrus spp. and Poncirus trifoliata. The survey was performed at 203 groves in the southern Korean Peninsula and Jeju Island. CVEV infection was determined by reverse transcription polymerase chain reaction detection and sequencing. The coat protein (CP) gene sequences obtained from the CVEV-infected samples showed high similarities (more than 98%) to the previously reported CVEV CP sequences. In summary, CVEV was detected in 136 groves (67%), in which 85.4% of Citrus junos and 77.8% of Citrus unshiu were infected by CVEV. In Jeju Island, the infection rate of CVEV was relatively higher (90.6%). Our result revealed that CVEV has spread widely in Citrus and Poncirus in Korea. Based on the result, the Korean quarantine agency decide to exclude CVEV from quarantine in Korea.

• The Plant Pathology Journal
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• v.40 no.2
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• pp.125-138
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• 2024

Citrus yellow vein clearing virus (CYVCV) is a member of the Alphaflexiviridae family that causes yellow vein clearing symptoms on citrus leaves. A total of 118 leaf samples from nine regions of six provinces in Korea were collected from various citrus species in 2020 and 2021. Viral diagnosis using next-generation sequencing and reverse transcription polymerase chain reaction (RT-PCR) identified four viruses: citrus tristeza virus, citrus leaf blotch virus, citrus vein enation virus, and CYVCV. A CYVCV incidence of 9.3% was observed in six host plants, including calamansi, kumquat, Persian lime, and Eureka lemon. Among the citrus infected by CYVCV, only three samples showed a single infection; the other showed a mixed infection with other viruses. Eureka lemon and Persian lime exhibited yellow vein clearing, leaf distortion, and water-soak symptom underside of the leaves, while the other hosts showed only yellowing symptoms on the leaves. The complete genome sequences were obtained from five CYVCV isolates. Comparison of the isolates reported from the different geographical regions and hosts revealed the high sequence identity (95.2% to 98.8%). Phylogenetic analysis indicated that all the five isolates from Korea were clustered into same clade but were not distinctly apart from isolates from China, Pakistan, India, and Türkiye. To develop an efficient diagnosis system for the four viruses, a simultaneous detection method was constructed using multiplex RT-PCR. Sensitivity evaluation, simplex RT-PCR, and stability testing were conducted to verify the multiplex RT-PCR system developed in this study. This information will be useful for developing effective disease management strategies for citrus growers in Korea.