基于BSA-seq技术的马铃薯块茎蛋白含量基因定位与分子标记开发

Gene mapping and molecular marker development of potato tuber protein content based on BSA⁃seq technology

【目的】开发与四倍体马铃薯蛋白含量相关的分子标记,加快选育高蛋白的马铃薯品种,提高马铃薯品种竞争力。【方法】以高蛋白马铃薯品种‘大西洋’为母本、低蛋白品种‘定薯1号’为父本构建分离群体,利用混池和高通量简化基因组测序技术相结合的方法(BSA-seq)对马铃薯块茎蛋白含量进行QTL定位,在定位区间开发与马铃薯块茎蛋白含量紧密连锁的SSR标记,并使用分离群体及四倍体马铃薯品种进行筛选验证。【结果】在2号、4号染色体共定位到3个控制马铃薯块茎蛋白含量的主效位点,分别位于2号染色体18.88~21.59 Mb,区间大小为2.71 Mb;4号染色体8.3~12.84 Mb,区间大小为4.54 Mb;4号染色体65.12~66.39 Mb,区间大小为1.27 Mb。根据定位区域、基因位置及参考基因组信息,使用NR、 Tr EMBL、 KEGG、 GO、 KOG、 swissprot、 PFAM共7个功能数据库对候选基因进行功能注释,共注释到719个候选基因,注释基因显著富集在玉米素合成代谢通路,该代谢通路可阻止蛋白质降解。在2号染色体18.88~21.59 Mb区间内开发分子标记pChr2-4。用分离群体、四倍体马铃薯品种结合田间表型对pChr2-4的准确性进行鉴定,结果显示,pChr2-4在离群体、四倍体马铃薯品种中的准确性分别为73.17%和81.82%,准确度较高。【结论】通过BSA混池测序,检测到3个与马铃薯块茎蛋白含量相关的区间。在2号染色体开发与马铃薯块茎蛋白含量紧密连锁的标记pChr2-4,该标记有助于马铃薯块茎蛋白含量分子标记辅助育种。

【Objective】The study aimed to select potato varieties with high protein and improve the competitiveness of potato varieties by dig⁃ging out and analyzing the key genes that controled the formation of protein during potato tuber development and developing molecular mark⁃ers related to the tetraploid potato protein content.【Method】In the study,the high protein potato variety‘Atlantic’was used as the female parent,and the low protein potato variety‘Dingshu⁃1’was used as the male parent to construct an isolation population.The method of BSA seq was used to locate the QTL of potato tuber protein content.SSR markers closely linked to potato tuber protein content were developed in the location interval,and the isolation population and tetraploid potato varieties were used for screening and verification.【Result】Three ma⁃jor loci controlling potato tuber protein contents were located on chromosomes 2 and 4,respectively 18.88-21.59 Mb on chromosomes 2,with an interval size of 2.71 Mb;Chromosome 4 was 8.3-12.84 Mb,with an interval size of 4.54 Mb;Chromosome 4 was 65.12-66.39 Mb,with an interval size of 1.27 Mb.According to the location area,gene location and reference genome information,seven functional data⁃bases,NR,Tr EMBL,KEGG,GO,KOG,swissprot and PFAM,were used to annotate candidate genes.A total of 719 candidate genes were annotated.The annotated genes were significantly enriched in the zeatin anabolic pathway,which could prevent protein degrada⁃tion.Molecular markerpChr2⁃4was developed in the 18.88-21.59 Mb region of chromosome 2.The accuracy ofpChr2⁃4in isolated popula⁃tion,tetraploid potato varieties and field phenotypes was identified.The results showed that the accuracy ofpChr2⁃4in isolated population and tetraploid potato varieties was 73.17%and 81.82%respectively,with high accuracy.【Conclusion】Three regions related to potato tuber protein content were detected by BSA mixed pool sequencing.The markerpChr2⁃4closely linked to potato tuber protein content was devel⁃oped on chromosome 2,which was helpful for potato tuber protein content molecular marker assisted breeding.