南瓜含糖量相关QTL的标记加密及候选基因预测

为探索南瓜果实含糖量相关性状的遗传规律,本试验以糖组分和含量差异显著的广东本地高代自交系品种(CMO-97)和泰国引进的高代自交系品种(CMO-E)为亲本,构建F₂分离群体,并基于高通量测序和亲本基因组重测序结果,开发与南瓜含糖量相关性状连锁的分子标记,对蔗糖葡萄糖比值性状所在的原始定位区间(qs/g19-a)进行遗传图谱加密,预测控制南瓜果实甜度的关键基因,筛选与果实糖含量性状紧密连锁的分子标记。结果表明,经筛选,在开发的50对InDel标记和12对KASP标记中共有9对InDel标记和6对KASP标记具有显著的多态性。加密后的19号连锁群包含 6 个KASP 标记、9 个InDel标记和 112 个SNP 标记,qs/g19-a 的定位区间由968.7 kb缩小至356.3 kb,对比参考基因组信息发现在缩小后的定位区间内共有56个基因,其中与糖含量相关的候选基因有4个。本研究结果为南瓜含糖量相关育种研究提供了参考和分子标记资源。

Marker Encryption and Candidate Gene Prediction of Sugar Content-Related QTL in Pumpkin

In order to understand the inheritance of sugar-related traits in pumpkin fruit, two high generation of inbred lines with significant difference in sugar content and composition, the guangdong local high line (CMO-97) and Thailand line (CMO - E), were used as the parents to build F₂ segregation population in this study. Based on the high-throughput sequencing and parental genome resequencing results, molecular markers linked to the sugar-related trait of the pumpkin were developed. The markers located in the original location mapping region of sucrose and glucose ratio (qs/g19-a) on the genetic map was encrypted. The key genes controlling sweetness of pumpkin were predicted and molecular markers closely linked to fruit sugar content were screened. The results showed that 9 pairs of InDel markers and 6 pairs of KASP markers were polymorphic among the 50 pairs of InDel markers and 12 pairs of KASP markers. The encrypted linkage group 19 contained 6 KASP markers, 9 InDel markers and 112 SNP markers. The qs/g19-a localization region was narrowed from 968.7 to 356.3 kb. Compared with the reference genome information, we found that there were 56 genes in the narrowed localization region, among which there were 4 candidate genes related to sugar content. The results of this study provide reference and molecular marker resources for breeding studies on pumpkin sugar content.