Genes & Genomics

, Volume 31, Issue 4, pp 325–332 | Cite as

Sequence polymorphism and chromosomal localization of 5S rDNA of three cultivated varieties of sweetpotato (Ipomoea batatas (L.) Lam.)

  • Eun Young Choi
  • Jun Hyung Seo
  • Bong Bo Seo


The 5S rDNA of plant is organized into clusters of tandem repeat units which include a coding region of 5S rRNA gene and variable sequences of nontranscribed spacer (NTS). In this study, we investigated sequence polymorphism and chromosomal localization of 5S rDNA in three cultivated varieties of sweet potato (Ipomoea batatas Lam.). Two different PCR products of 5S rDNA were amplified from all three varieties, as approximately 0.25 kb and 0.34 kb with multiples. In sequence analysis, the 5S rDNA ofI. batatas were discriminated from four consensus sequences by in reasonable sizes and molecular informative factors. Four consensus sequences were divided into three short sequences, including 263, 253, and 243 – 283 bp by sequence variation between 160 and 186 bp in NTS region, and one long sequence with 340 bp. To identify molecular relationship among varieties, phylogenetic analysis was applied. A total of 35 sequenced clones in this study were classified into four groups in phylogenetic tree. Interestingly, two varieties included all four groups, but one variety only two groups. To localize the physical map of 5S rDNA, fluorescencein situ hybridization (FISH) was performed in metaphase chromosomes of each varieties. In 90 chromosomes ofI. batatas, 6 loci of 5S rDNA were detected in chromosomes for all varieties. Our results will help to further more understand the genomic relationship inI. batatas, to investigate molecular relationship among varieties.

Key words

Ipomoea batatas Lam fluorescencein situ hybridization (FISH) 5S rRNA genes parsimonious study 


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© The Genetics Society of Korea & Springer 2009

Authors and Affiliations

  1. 1.Department of BiologyKyungpook National UniversityDaeguKorea

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