Determination S-Genotypes and Identification of Five Novel S-RNase Alleles in Wild Malus Species.

Apple ( Malus × domestica Borkh.) is a typical Rosaceae species that exhibits gametophytic self-incompatibility (GSI) controlled by polymorphic S-alleles. In this study, the S-alleles of wild Malus species were amplified, sequenced and compared using polymerase chain reaction (PCR) technology. 21 S-alleles were identified in 27 wild Malus species. The results indicated that the overwhelming majority of S-alleles between wild Malus species and cultivars shared identical sequences. Simultaneously, five new S alleles (designated S- S) were identified in wild Malus species. There are the S-RNase in M. angustifolia (Ation) Michaux, S-RNase in M. orientalis Uglitzk. Ex Juz. and M. sylvestris (L.) Mill., S-RNase in M. tschonoskii (Maxim.) C.K. Schneid. and M. sieversii (Ldb.) Roem., S-RNase in M. komarovii (Sarg.) Rehd. and M. kansuensis (Batal.) C. K. Schneid., S-RNase in M. manshurica (Maxim.) V. Komorov wild Malus species. Additionally, an S-RNase was cloned in wild Malus prunifolia var. ringo, which have the same open reading frame as Malus × domestica cv. Fuji, but lacked whole intron. [ABSTRACT FROM AUTHOR]