黄瓜黄叶基因YL的精细定位及候选基因预测

Fine mapping and candidate gene prediction of yellow leaf gene YL in cucumber

以黄瓜自交系WD_(1)为材料,采用甲基磺酸乙酯(EMS)诱变方式获得了一个稳定遗传的黄叶突变体yl;以黄叶突变体yl为父本、黄瓜自交系S52为母本,构建F_(2)群体,并对黄叶突变体yl、S52、F_(1)和277株F_(2)群体的叶色性状进行调查和遗传分析。结果表明:该突变体受一个隐性核基因控制,且绿色叶对黄色叶为完全显性。利用黄瓜7条染色体上的235对SSR引物对F_(2)群体的野生型与突变体DNA池进行混合分组分析法(BSA)分析,筛选得到2个DNA池间多态性标记5对,初步将该基因定位在黄瓜4号染色体分子标记SSR15682和SSR05415之间。通过进一步开发和筛选亲本间多态性分子标记,利用277株F_(2)群体将YL基因定位于黄瓜4号染色体上的分子标记In Del4-9和In Del4-10之间,物理距离为936.39 kb。利用20株黄化苗DNA混池基因组重测序数据和课题组已有的黄瓜自交系WD_(1)、S52重测序数据以及黄瓜9930基因组数据,对定位区间内基因进行序列分析,推测Csa4G297530为候选基因。

A stable yellow leaf mutant yl was obtained from cucumber inbred line WD_(1)by ethyl methane sulfonate(EMS);Using mutant yl as male parent and cucumber inbred line S52 as female parent,F_(2)population was constructed,and leaf color traits of mutant yl,S52,F_(1)and 277 F_(2)population were investigated and analyzed.The results showed that the mutant was controlled by a recessive nuclear gene,and green leave was completely dominant to yellow leave.Using 235 pairs of SSR primers on 7 chromosomes of cucumber,the wild type and mutant DNA pools of F_(2)population were analyzed by bulked segregate analysis(BSA).Five pairs of polymorphic markers between two DNA pools were screened.The gene was initially located between SSR15682 and SSR05415 on chromosome 4 of cucumber.By further development and screening of polymorphic markers among parents,the population of 277 F_(2)was used to locate YL gene between InDel4-9 and InDel4-10 on chromosome 4 of cucumber,with a physical distance of 936.39 kb.The sequence analysis of the genes in the localization range was carried out by using the data of 20 mutant seedlings DNA mixed pool genome sequencing data,the resequencing data of cucumber inbred lines WD_(1)and S52 and genome data of cucumber 9930.It was speculated that Csa4 G297530 was the candidate gene.