Karyotype Analysis of Rosa laxa,Modern Rose and Their Interspecific Hybrids

In this study,hybridization was conducted between Rosa laxa(2n=2x=14)and Rosa cv.‘Kardinal',‘Solidor',‘Yuzen'(2n=2x=28),and five,five and six F1hybrids were obtained from cross combinations of R.laxaבKardinal',R.laxaבSolidor'and R.laxaבYuzen',respectively.The karyotypes of parents and their interspecific hybrids were analyzed using traditional squashing method.The results showed that 15F1hybrids were triploid,except that one of the hybrids between R.laxa and ‘Kardinal' was diploid.The karyotype formula of R.laxa was 12m+2sm belonging to 1A.Karyotype formulas of ‘Kardinal',‘Solidor',‘Yuzen'were 28m,28m,24m(2SAT)+4sm,respectively,of which belonged to 1A, 1Band 2B.Karyotype formulas of hybrids of R.laxaבKardinal'included 1A,1Band 2A.Karyotype formulas of hybrids of R.laxaבSolidor'included 1Aand 1B.Karyotype formulas of hybrids of‘Yuzen'×R.laxaincluded 1A,1Band 2B.According to the karyotype characters,triploid F1hybrids were true progeny,however,the hybrid authenticity identification of diploid F1hybrids could not be confirmed.