Identification of S-genotypes on the pear cultivars and wild forms of Pyrus ussuriensis

Total of 23 cultivars and wild forms of Pyrus ussuriensis Maxim.were used as material for identifying their S-geno-type using peculiar primers designed by the conserved regions of pear S-RNase structure,PCR amplifications,amplification product cloning,sequencing and sequences alignment analysis.Based on principle of homology of 100% of S gene nucleotide sequence,20 S-RNase genes were determined;17 S-RNase genes of them,Sb,Sc,Sd,Sh,S8,S12,S13,S16,S19,S27,S29,S30,S31,S34,S36,S41,S42,were the same as these known on the GenBank;one novel S-RNase was discovered in pear cultivar Xiaoxiangshui,PCR bands 509 bp,accession numbers FJ490411;One of S gene from Hanhongli and Zaoli 18 was unidentified respectively.The S-genotypes of 20 pear cultivars were identified as follows:Xiehuatian(S29S34),Shanyali(S30S36),Pingxiangli(SdS31),Matihuang(S16S19),Hanxiang(S12S31),Longxiang(S12S16),Zaoxiang(S19S42),Balixiang(S19S30),Jian-bazi(S27Sh),Ruanbazi(S16S36),Tangli(S27S30),Suanliguozi(S19S41),Yanbian Daxiangshui(SdS12),Nanguoli(S13S34),Dananguo(S13S34),Youhong(S13S34),Xiaoxiangshui(S27Sx),wild type Shanli 1(S8S27),wild type Shanli 3(SbS41),wild type Shanli 4(ScS42).The S-genotypes of Dacili(P.bretschneideri) was S19S27,Hanhongli(P.ussuriensis) was S27Sx,Zaoli 18(P.pyrifolia) was SdSx.