Species-specific repeated DNA sequences from Petunia

Repeated DNAs have been isolated from Petunia hybrida and their distribution and organisation in different Petunia species studied. Several sequences examined can be used as probes to distinguish species with 14 chromosomes from P. parviflora, which has 18. In addition, three sequences can distinguish white-flowered species (P. axillaris, P. parodii) from pink-flowered species (P. violacea, P. inflata). One sequence which is detected only in species with 14 chromosomes was found to be present in tandemly-arranged, AT-rich 168 base-pair repeats. The use of these sequences in phylogenetic studies and somatic cell genetics is discussed.