白梨品种4个新S基因的分离与鉴定

利用S_1-8-RNase氨基酸保守序列‘FTQQYQ’和‘IIWPNV’设计兼并引物, 对白梨4个品种冬黄、新梨一号、红皮酥和博山池的基因组DNA进行PCR扩增。PCR产物限制性酶切分析显示: 新梨一号和冬黄各含有一个S₈ - 等位基因。DNA序列测定和生物信息学分析表明, 这4个品种中含有与已报道的S_1-19等位基因有差异的S基因, 经分析鉴定为新的S 等位基因, 分别命名为S₂₀ - 、S₂₂ - 、S₂₆ - 、S₂₇ - 等位基因(GenBank登录号分别为: AY250988、AY250990、AY339396、AY339397) 。冬黄、新梨一号、红皮酥和博山池的S基因型分别为S₈ S₂₀、S₈ S₂₂、S₁₂ S₂₆和S₁₉ S₂₇。

Isolation and Identification of Four New S-RNase Genes of White Pear (Pyrus bretschneideri)

PCRs were performed on genomic DNAs of four Chinese white pear (Pyrus bretschneideri) cultivars Donghuang, Xinliyihao, Hongpisu and Boshanchi using degenerate primers derived from conserved amino acids FTQQYQ and anti-IIWPNV of Japanese pear S1-8-RNases. Restricted digestion analysis of PCR products revealed that Xinliyihao and Donghuang had a common S8-allele. Sequencing and bioinformatics analysis of undigested PCR product showed that four alleles from the four cultivars were distincted from published S1-19-alleles at the DNA and deduced amino acid sequences level, thereby being identified as new alleles. They were named as S20-, S22-, S26-and S27-alleles, respectively (GenBank accession numbers AY250988, AY250990, AY339396 and AY339397). Finally, the four cultivars were S-genotyped as follows: Donghuang (S8S20), Xinliyihao (S8S22), Hongpisu (S12S26) and Boshanchi (S19S27).