무궁화속 식물(Hibiscus spp.)은 전세계적으로 약 300여 종이 존재하며, 무궁화(H. syriacus) 외에 황근(H. hamabo), 부용(H. mutabilis)이 우리나라에서 자생하고 있다. 이 외에도 H. paramutabilis(노산부용), H. sinosyriacus(중국무궁화) 등이 우리나라에서 관상용으로 흔히 재배되고 있고, 그 중 일부는 상호교배가 가능하다. 또한 무궁화속의 기본 염색체 수(x=7, 8, 9, 11, 12, 15, 17, 19, 20, 39)가 다양하게 보고되었으나, 정확한 체세포 염색체 수는 밝혀지지 않았다. 본 연구에서는 H. sinosyriacus ‘Seobong’과 H. syriacus ‘Samchully’를 정역교배하여 2010년 선발된 ‘Tohagol Red’와 2012년 최종 선발된 ‘Daewangchun’의 특성을 조사하고, Flow cytometry를 이용한 DNA content와 FISH 기법을 통하여 양친과 후대의 핵형을 분석하였다. 특성조사 결과, 잎의 가장자리는 ‘Samchully’의 경우 날카로운 톱니모양을 나타내었고 ‘Seobong’의 경우 둥근 톱니모양을 나타내었다. ‘Daewangchun’의 경우 약간 둥근 모양으로, 잎의 크기는 엽장 8.2cm, 엽폭 5.4cm 로 모부본의 중간으로 나타났다. ‘Tohagol Red’는 날카로운 톱니모양으로, 잎의 크기는 엽장 7.2cm, 엽폭 5.7cm로 나타났다. ‘Daewangchun’의 꽃의 크기는 지름이 13.8cm로 모부본과 비슷하였으나, 단심의 크기가 2.1cm로 모부본보다 0.5cm 이상 큰 것이 특징이었다. 화색은 분홍색으로 ‘Samchully’의 화색에 가까웠다. ‘Tohagol Red’의 꽃의 지름은 12.6cm로 모부본과 비슷하였으나, 단심의 크기가 1.1cm로 모부본보다 0.5cm 이상 작은 것이 특징이었다. 화색은 분홍색으로 ‘Samchully’의 화색에 가까웠다. Flow cytometry를 이용하여 DNA content를 측정한 결과, ‘Seobong’이 1928.77 Mbp/1C (1.97 pg/1C), ‘Samchully’는 2820.34 Mbp/1C (2.88 pg/1C) 으로 나타났다. ‘Tohagol Red’와 ‘Daewangchun’의 DNA content는 각각 1914.70 Mbp/1C (1.96 pg/1C), 1975.88 Mbp/1C (2.02 pg/1C) 으로 나타났다. DAPI로 염색하여 광학현미경으로 염색체를 관찰한 결과, 모부본인 ‘Seobong’은 2n=80, ‘Samchully’는 2n=126으로 나타났으며, ‘Tohagol Red’와 ‘Daewangchun’은 각각 2n=82로 나타났다. FISH 분석 결과, ‘Seobong’은 45S rDNA signal가 6개, 5S rDNA signal은 2개로 확인되었고, ‘Samchully’는 45S rDNA signal은 6개, 5S rDNA signal은 3개로 확인되었다. ‘Tohagol Red’는 45S rDNA signal은 7개, 5S rDNA signal은 2개, ‘Daewangchun’은 45S rDNA signal은 7개, 5S rDNA signal은 2개로 확인되었다.
There are about 300 species of Hibiscus spp. in the world. In addition to H. syriacus, H. hamabo and H. mutabilis are native to Korea. H. paramutabilis and H. sinosyriacus are commonly cultivated for ornamental use in Korea, and some of them are capable of crossbreeding. The number of basic chromosomes in Hibiscus spp. (x = 7, 8, 9, 11, 12, 15, 17, 19, 20, 39) was variously reported but the exact number of somatic chromosomes was not revealed. Basic chromosome number of H. syriacus is x = 20 and most cultivars are tetraploid, 2n = 4x = 80 (Skovsted 1941). H. sinosyriacus, 2n = 4x = 80. In this study, the characteristics of ''Tohagol Red'' selected in 2010, ''Daewangchun'' selected in 2012 by reciprocal cross between H. sinosyriacus ''Seobong'' and H. syriacus ''Samchully'' and their parent were investigated and measured DNA contents by Flow cytometry. FISH detection of the 5S and 45S rDNA was used to analyze the parental and progenies karyotype. As a result of characteristic investigation, the leaf margin of ''Samchully'' was acute and ‘Seobong’ was crenate. The leaf margin of ‘Daewangchun’ was oval, the length of leaf was 8.2cm, the width of leaf was 5.4cm. The leaf margin of ‘Tohagol Red’ was acute, the length of leaf was 7.2cm, the width of leaf was 5.7cm. The diameter of flower of ‘Daewangchun’ was 13.8cm, which was larger than 2cm than the parents, the length of red eye was characterized by a radius of 2.1cm, larger about 1cm than that of the parents. The color of ‘Daewangchun’ appeared pink, similar to that of ‘Samchully’. The diameter of flower of ‘Tohagol Red’ was 12.6cm, which was larger than 1cm than the parents, the length of red eye was was characterized by a radius of 1.1cm, smaller about 1cm than that of the parent. The color of ‘Tohagol Red’ appeared pink, similar to that of ‘Samchully’. DNA content of ‘Seobong’ was measured to 1928.77 Mbp/1C (1.97 pg/1C). DNA content of ‘Samchully’ was measured to 2820.34 Mbp/1C (2.88 pg/1C). DN A content of ‘Daewangchun’ was measured to 1975.88 Mbp/1C (2.88 pg/1C). DN A content of ‘Tohagol Red’ was measured to 1914.70 Mbp/1C (1.97 pg/1C). The results of staining with DAPI and observing the chromosome with an optical microscope, ''Seobong'' was 2n = 80, ''Samchully'' was 2n = 126, as parents, Hibiscus cultivar ''Tohagol Red'' and ''Daewangchun'' were 2n = 82. FISH analysis results are as follows. ''Seobong'' was confirmed to be appeared six 45S rDNA signals and two 5S rDNA signals. ''Samchylly'' was confirmed to be appeared six 45S rDNA signals and three 5S rDNA signals. ''Daewangchun'' was confirmed to be appeared seven 45S rDNA signals and two 5S rDNA signals. ''Tohagol Red'' was confirmed to be appeared seven 45S rDNA signals and two 5S rDNA signals. These results are expected to be useful as a variety of basic data on the genetic analysis and the cultivation of new crops.