| الوصف: |
Determination of nuclear DNA content, genome sizes, and ploidy level and, information on cytogenetic characteristics are all prerequisite of modern plant breeding. However, cytogenetic study of Hibiscus species is often hampered by the similarity in morphology and by the small size of mitotic chromosomes. The goal of the study was to ascertain the chromosome number, karyomorphology, distribution of 5S and 18S rDNA loci, chromosome length, and centromere positions as well as the ploidy level, genome sizes, 2C-DNA content of winter-hardy Hibiscus: H. syriacus ‘Saejamyung’, H. sinosyriacus ‘Seobong’, H. moscheutos ‘Luna Red’ and, H. paramutabilis. 5S rDNA and 18S rDNA loci were detected by fluorescence in situ hybridization (FISH). According to the FISH results, there are two 5S rDNA loci in H. syriacus, H. sinosyriacus, and H. moscheutos, and four 5S rDNA loci in H. paramutabilis. The range in length of somatic chromosomes in H. syriacus, H. sinosyriacus, H. moscheutos, and H. paramutabilis is 2.66- 7.06, 3.18-7.31, 2.91-5.23, and 4.75-7.60 µm, respectively. The 2C-DNA content of H. syriacus, H. sinosyriacus, and H. moscheutos are very similar, the amount was 4.06, 4.11, and, 2.06 pg, respectively whereas, H. paramutabilis has nearly double and the amount was 4.18 pg. These findings will contribute to the detailed cytogenetic assessment of Hibiscus and thus benefit plant breeding in this genus. |
