Hybrid identification and morphological evaluation of modern roses( Rosa hybrida )×Rosa rugosa

Four cross combinations between modern rose cultivars( Rosa hybrida,2n = 4x = 28),as female parents,and R. rugosa cultivars( 2n = 2x = 14),as male parents,were carried out,and thirteen F1 hybrids were obtained,among which seven hybrids were chosen to be evaluated and identified by morphological observation,flow cytometry,karyotype analysis and simple sequence repeat( SSR)markers. The results showed that F1 hybrids integrated the morphological characteristics of both R.hybrida and R. rugosa. Both flow cytometry analysis and karyotype analysis showed that the 7 hybrids were all triploids( 2n = 3x = 21),karyotype parameters of the hybrids were between the female and male parents. The karyotype of most hybrids was 1A. The results of 11 SSR markers indicated that all of the 7selected hybrids contained the specific bands of both parents. All the morphological,cytological,and SSR marker data proved that all hybrids integrated the genetic material and morphological traits of both modern rose cultivars and R. rugosa cultivars, which provided new germplasm materials for the improvement of modern rose using R. rugosa. The results also show that flow cytometry analysis can be used to rapidly identify hybrids whose parents have different ploidy.