A cytogenetic and molecular cytogenetic comparison among six wild individuals and four cultivars of Iris ensata Thunb.

Abstract

Chromosome variation of wild and cultivated Iris ensata Thunb. was investigated by the standard chromosome analysis and modern molecular cytogenetic analysis by using fluorescence in situ hybridization detecting 18S and 5S rDNA sites. In the standard chromosome analysis, the chromosome numbers of ten individuals studied were 2n=24, and 12 chromosomes were morphologically similar among the individuals. On the other hands, the sizes of 18S rDNA sites were varied among the individuals, though 18S and 5S rDNA sites were uniformly existed on six and two chromosome, respectively. The larger and smaller 18S rDNA sites were observed on a single chromosome, and these chromosomes were morphologically similar among individuals. These aspects suggested that the partial chromosome changes such as addition and deletion occurred on the fixed chromosome in I. ensata.