Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences/Key Laboratory of Biology and Genetic Improvement of Tuber and Root Crop, Ministry of Agriculture and Rural Affair, Beijing 100081, China.
Int J Mol Sci. 2018 Oct 8;19(10):3065. doi: 10.3390/ijms19103065.
Early maturity is one of the most important agronomical traits in potato breeding. To identify the DNA segment that codes for early maturity, a tetraploid potato segregation population of "Zhongshu 19" × "Zhongshu 3" was genetically analyzed, using a combination of high throughput simplified genome sequencing (2b-RAD) and bulked segregant analysis (BSA). The DNA segment related to the early-maturity trait was identified at the 3.7~4.2 Mb locus on the short arm of chromosome 5. Eight molecular markers were developed, of which five were closely linked to the early-maturity trait loci. Additionally, 42 simple sequence repeats (SSR) markers were constructed based on the reference sequence of group Phureja DM1-3 516 R44 (DM). Using the TetraploidMap software, the linkage map of chromosome 5 was constructed with 50 markers. The total map length was 172 centiMorgan (cM), with an average genetic distance of 3.44 cM. Correlating molecular and phenotypic data of the segregating population, the mapped Quantitative Trait Loci (QTL) on the short arm of chromosome 5 contributed to 33.55% of the early-maturity phenotype. The early-maturity QTL was located at 84 cM, flanked by the SSR5-85-1 and SCAR5-8 markers. The QTL was fine-mapped to 471 kb. Using DNA sequence annotation, 34 genes were identified in this region, 12 of them with unknown function. Among the other 22 annotated genes, E3 ubiquitin ligase gene could be related to maturity and regulation of tuber formation. The constructed QTL map is a useful basic tool for the cloning of early-maturity related genes in tetraploid potatoes.
早熟是马铃薯育种中最重要的农艺性状之一。为了鉴定编码早熟的 DNA 片段，利用高通量简化基因组测序（2b-RAD）和混池分离分析（BSA），对四倍体马铃薯杂交群体“中薯 19”ד中薯 3”进行了遗传分析。在 5 号染色体短臂 3.7~4.2 Mb 位点鉴定到与早熟性状相关的 DNA 片段。开发了 8 个分子标记，其中 5 个与早熟基因座紧密连锁。此外，基于 Phureja DM1-3 516 R44（DM）参考序列构建了 42 个简单序列重复（SSR）标记。利用 TetraploidMap 软件，构建了 50 个标记的 5 号染色体连锁图谱，图谱总长度为 172 厘摩（cM），平均遗传距离为 3.44 cM。将分子数据与分离群体的表型数据进行关联，5 号染色体短臂上的定位 QTL 对早熟表型的贡献率为 33.55%。早熟 QTL 位于 SSR5-85-1 和 SCAR5-8 标记之间的 84 cM 处，将其精细定位在 471 kb 范围内。利用 DNA 序列注释，在该区域鉴定到 34 个基因，其中 12 个基因功能未知。在其他 22 个注释基因中，E3 泛素连接酶基因可能与成熟和块茎形成的调节有关。构建的 QTL 图谱是四倍体马铃薯早熟相关基因克隆的有用基础工具。
