Estimation of nuclear DNA content of 17 Chinese wild rose species by flow cytometry

Using four different standard plants (Glycine max Merr.‘Polanka’,Vigna radiata(L.) Wilczek,Lycopersicon esculentum Miller,and Zea mays L.) as outer calibrations and diploid taxon Rosa×lichiangensis Yü et Ku as the inner calibration,we estimated the nuclear genome sizes of 17 wild roses in China using flow cytometry based on the improved LB 01 buffer.Simultaneously,traditional chromosome tableting was performed to verify ploidy levels.The nuclear DNA contents and genome sizes of three diploid species (Rosa shangchengensis T.C.Ku,Rosa kwangtungensis Yü et Tsai and Rosa roxburghii f.inermis S.D.Shi),one triploid species (Rosa corymbulosa Rolfe),and one tetraploid species (Rosa beggeriana Schrenk) were reported in this study for the first time.The determined ploidy levels based on flow cytometry were consistent with those obtained by the traditional chromosome tableting technique.These findings enrich the cytogenetic resources of Rosa L.in China and offer a basis for the breeding of new strains.