Intrasectional and intersectional cross breeding of Paeonia and karyotype analysis and SSR identification of some hybrids

In order to select the proper cross combinations with high compatibility, hybridization was carried out between Paeonia lactiflora 'Zhu Sha Pan' as female parent and 6 cultivars of Sect. Paeonia and 4 cultivars of Sect. Moutan as male parents. Meanwhile, hybrids were identified by karyotype analysis and SSR markers. The results showed that:1) Hybridization in Sect. Paeonia had a high compatibility, with an average seed setting rate of 5 seeds per flower; interspecific hybridizations of Sect. Paeonia had a poor compatibility; sectional hybridizations were incompatible, only cross combination 'Zhu Sha Pan' ×'Dao Da Chen' seeded. 2) Karyotype analysis showed that hybrids ZC4, ZC5, ZC6 and ZC7 were triploid; Among 50 SSR primers, 7 polymorphic markers were amplified and the hybrids ZC4, ZC5, ZC6 and ZC7 contained specific bents of parents, which were true hybrids. The results suggested that interspecific hybridization between 'Zhu Sha Pan' and 'Garden Peace', 'Pink Teacup', 'Cream Delight' could seed; sectional hybridization 'Zhu Sha Pan' ×'Dao Da Chen' could break the cross incompatibility. SSR markers could be applied for the early hybrid identification of Paeonia.