Characterization of Ty3-gypsy-like elements in Hibiscus syriacus.

Southern blot analysis revealed a ubiquitous distribu-tion and high copy number of Ty3-gypsy-like elements in the genome of Hibiscus syriacus. Comparative phylogenetic analysis of the large subunit of Rubisco and the integrase region of Ty3-gypsy elements in various plant species indicated that the retrotransposon-like sequences have different evolutionary histories and their own unique polymorphism in the H. syriacus population. Sequence-tagged site-restriction fragment length polymorphisms (STS-RFLP) analysis also indicated great variability in the numbers and sequences of Ty3-gypsy-like elements within H. syriacus varieties. Ty3-gypsy-like elements may still be active within H. syriacus, since Northern analysis of wounded leaves of H. syriacus variety Saehan with a probe for the integrase domain gave strong hybridization signals. The sequence heterogeneity and ubiquity of the Ty3-gypsy-like elements in H. syriacus genomes could provide reliable DNA markers for line identification as well for the analysis of genetic diversity in H. syriacus.