SSCP Analysis of Variations in Haplotypes of Citrus Tristeza Virus Isolated from Yuzu (Citrus junos) in Geographically Separate Regions of Korea

• Published in: Journal of plant biology = Singmul Hakhoe chi Vol. 49; no. 1; pp. 88 - 96
• Main Authors: Dae Hyun Kim, Hye Kyung Shim, Jae Wook Hyeon, Hyeog Mo Kwon, Kwang Sik Kim, Min Su Choi, Jin Kyung Lee, Dong Giun Kim, Ju Sung Yang, Suk Chan Lee
• Format: Journal Article
• Language: Korean
• Published: 한국식물학회 28.02.2006
• Subjects: citrus tristeza virus; p20 gene; single-strand conformation polymorphism analysis; viral RNA population; 생물학; p20 gene; citrus tristeza virus; single-strand conformation polymorphism analysis; viral RNA population
• ISSN: 1226-9239; 1867-0725

Yuzu (Citrus junos) trees were examined from six geographically separate provinces in the Republic of Korea, including four islands (Geoje, Namhae, Wan, and Jeju), 1 peninsula (Goheung), and 1 inland area (Boseong). The population of sequence variants of citrus tristeza virus (CTV) was isolated and analyzed by single-strand conformation polymorphism (SSCP) analysis of cDNA from the p20 gene. SSCP profiles of 65 PCR products showed different band patterns but with similar intensities. Sixteen haplotypes were subgrouped according to their SSCP profiles and severity of symptoms. Their genomes were sequenced and compared. DNA analysis of the p20 genes revealed nucleotide identities ranging from $88-99.8\%$. Based on SSCP analysis, the pathologically mild isolates of CIV yielded two to three DNA bands, whereas the most virulent isolates contained more than two bands. Comparisons of these physically separate haplotypes suggest that CIV isolates with multiple SSCP profiles could have arisen as a result of a mixed infection and genetic recombination of two divergent isolates. Plants with severe disease symptoms, such as stem pitting, closely corresponded to a CTV strain showing typical SSCP profiles in Florida (USA) and Japan.