与梨黑星病抗性基因连锁的AFLP标记筛选及SCAR标记转化

以‘鸭梨’(Pyrusbretschneideri)ב雪青’梨(P.bretschneideri×P.pyrifolia)F1代群体(97株)为试材,采用扩增片段长度多态性(amplified fragment length polymorphism,AFLP)技术和集群分类法(bulked segregantanalysis,BSA)筛选与梨抗黑星病基因连锁的分子标记。通过64对AFLP标记引物在亲本和分离群体中的筛选和验证,获得与梨抗黑星病基因紧密连锁标记两个,即ACA/CAA-179和AAC/CAG-198。它们与抗黑星病基因的遗传距离分别为5.2和8.3cM。对AFLP标记片段的克隆和测序结果显示其长度分别为179和198bp。根据序列信息设计特异引物,在杂交后代群体上的PCR分析表明AFLPACA/CAA-179标记被成功转换成SCAR标记,命名为SCAR-117。本研究结果将有助于对抗黑星病梨品种资源的分子鉴定及杂种后代的早期辅助选择。

Identification of AFLP-derived SCAR Markers Linked to the Pear Scab Resistance Gene

Pear scab is one of the most harmful diseases in pear production. Using 97 F1 progenies produced by the cross‘Yali’（susceptible）בXueqing’（resistant），markers linked to pear scab resistance gene were screened by amplified fragment length polymorphism（AFLP） technique combined with bulked segregant analysis（BSA）method. Two molecular markers which linked to pear scab resistant gene had been identified from 64 pairs of AFLP primer，named as ACA/CAA-179 and AAC/CAG-198. The genetic distance to pear scab resistant gene were 5.2 cM and 8.3 cM，respectively. Sequencing results indicated that the length of the two specific fragment amplified were 179 bp and 198 bp，respectively. The specific primers were further designed based on the sequence information，and then were utilized to analyze the F1 population by PCR. Results showed that AFLPACA/CAA-179 had been successfully converted into SCAR marker，and named as SCAR-117. This result will be helpful for molecular identification of germplasm and early selection of progenies which are resistant to pear scab.