황기류 식물 3종의 세포유전학적 분석

Abstract

To elucidate cytogenetic differences, karyotype analysis and FISH (fluorescence in situ hybridization) with 45S and 5S rDNAs were carried out in the three Astragalas species: Astragalas membranaceus Bunge, A. membranaceus var. alpinus Nakai and A. mongholicus Bunge. The somatic metaphase chromosome numbers of all three species were 2n = 2x = 16 and the size of chromosomes ranged 2.19 ~ 5.73㎛. The chromosome complement of A. membranaceus consisted of each four pairs of metacentrics (chromosomes 3, 4, 6 and 7) and submetacentrics (chromosomes 1, 2, 4 and 8). In A. membranaceus var. alpinus, the chromosome complement consisted of two pairs of metacentrics (chromosomes 4 and 8) and six pairs of submetacentrics (chromosomes 1, 2, 3, 5, 6 and 7). A. mongholicus had three pairs of metacentrics (chromosomes 6, 7 and 8) and five pairs of submetacentrics (chromosomes 1, 2, 3, 4 and 5). Using bicolor-FISH, one pair of 45S and 5S rDNA signals could be detected on the centromeric regions of chromosomes 8 and 7 of A. membranaceus and A. mongholicus, respectively. In contrast, A. membranaceus var. alpinus had one pair of 45S signals on the centromeric region of chromosome 8 and two pairs of 5S rDNA signals on the short arms of chromosomes 7 and 8.