Karyotype analysis of Paeon/ax femo/ne/'High Noon' based on GISH supplies an improved method for accurate karyotyping of hybrids in Paeon fa

摘要

The inter-subsectional distant hybridization between subsect. Delacqyanae and subsect Vaginatae of Paeonia sect Moutan is a significant direction in modern tree peony breeding. Paeonia x lemoinei 'High Noon' is an inter-subsectional cultivar with goodornamental and resistant traits. In spite of its sterility in most cases, 'High Noon' was still the parent of a few excellent hybrids. Because of the high morphological similarity of most chromosomes in Paeonia, it is very difficult to get accurate karyotype for the hybrids. Using genomic in situ hybridization (GISH), we clearly identified the parent genomes, genome-A (from P. suffruticosa) and genome-B (from P. delavayi), in 'High Noon', and obtained a more accurate karyotype, with a formula of 2n=2jf=10=7m+lsm+2st (1SAT), than the traditional karyotyping by conventional staining. To our knowledge, this is the first application of GISH in Paeonia. It reveals an improved method for accurate karyotype and genetic analysis of hybrids in Paeonia.