Chrysanthemum stunt viroid (CSVd) is a serious pathogen affecting chrysanthemum that has caused significant economic losses to Chrysanthemum flower production worldwide. Control of CSVd disease is difficult due to its contagious nature and long latent period in the field. As chrysanthemum is most often produced by implanting seedlings, it is necessary to diagnose CSVd infection before cultivation. In this study, we screened CSVd infection in seedlings from 30 varieties including 5 domestic, 6 Japanese, and 19 European varieties. Molecular diagnosis of the combination of RT-PCR and nested PCR showed that CSVd was not detected by the first RT-PCR but detected by the second nested PCR analysis in 10 varieties, including 1 domestic, 2 Japanese, and 7 European varieties. Further comparison of 10 identified CSVd nucleotide sequences showed that those are highly conserved (99-100%) and the most similar to an isolate (AB006737) identified in Hokkaido, Japan. Our study suggests that the combination of RT-PCR and nested PCR analysis is successful for the CSVd diagnosis of seedlings and the molecular diagnosis is necessary to prevent the introduction and propagation of viroid disease into the fields.

• Jae-Kyoung Shim(School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University)
• S.M. Hemayet Jahan(School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University)
• Bong-Nam Chung(National Horticultural Research Institute, Rural Development Administration)
• Sukchan Lee(Department of Genetic Engineering, Sungkyunkwan University)
• Chang-Kil Kim(Department of Horticultural Science, College of Agriculture and Life Sciences, Kyungpook National University)
• Kyeong-Yeoll Lee(School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Institute of Plant Medicine, Kyungpook National University) Corresponding author