与苹果Co基因紧密连锁的RAPD标记的筛选及其SCAR标记转换

以短枝富士(Spur Fuji)X舞姿(Telamon)的105株F1群体为试材，利用RAPD技术，结合集群分类分析法(BSA)进行了苹果柱型基因(Co)分子标记的研究。通过对300条随机引物的筛选，获得一个与Co基因紧密连锁的RAPD标记S1142682，连锁距离为2．86cM。对该标记片段进行序列测定，然后根据序列特点设计了4条特异引物(其中正向引物与反向引物各两条)。PCR结果显示，这4条引物的4种组合都可以扩增出柱型性状的特征带。选其中之一进行群体上的分析，结果表明该SCAR标记特征带与柱型性状的共分离行为与原RAPD标记表现一致。可见，此组合的引物可以作为该SCAR标记的特异引物。通过对S1142682标记片段序列分析发现，在 45～ 251区域含有一个可编码68个氨基酸残基的ORF。

Screening of a RAPD Marker Tightly Linked to Co Gene in Apple and the SCAR Marker Conversion

A DNA marker linked to the columnar gene (Co) in apple (Malus domestica) was explored based on the population of 105 progenies of 'Spur Fuji'×'Telamon' by bulk segregant analysis (BSA) and Random Amplified Polymorphic DNA (RAPD) technique. A total of 300 random primers were screened and a RAPD marker(S1142682)closely linked to Co gene(2.86 cM) was identified and then sequenced. Four specific PCR primers (two forward primers and two reverse primers) were designed,and the products of SCAR-PCR indicated that all the four pairs of primers could amplify polymorphic bands between columnar and non-columnar traits,so any of them could serve as the specific SCAR primers. One pair of these specific primers was chosen to amplify each individual in the population,and the result showed that the co-segregation pattern of this SCAR marker and Co gene was the same as that of the RAPD marker. Furthermore,it was found that the nucleotide sequence of the RAPD marker fragment contained an open reading frame (ORF) that could encode 68 deduced amino acid residues at the position of +45～+251.