DataSheet_6_QTL identified that influence tuber length–width ratio, degree of flatness, tuber size, and specific gravity in a russet-skinned, tetraploid mapping population.xlsx

Potato tuber shape, size, and specific gravity are important agronomic traits in the russet market class of potatoes with an impact on quality, consistency, and product recovery of processed foods such as French fries. Therefore, identifying genetic regions associated with the three traits through quantitative trait locus/loci (QTL) analysis is a crucial process in the subsequent development of marker-assisted selection for use in potato breeding programs. QTL analysis was conducted on a tetraploid mapping population consisting of 190 individuals derived from the cross between two russet-skinned parents, Palisade Russet and the breeding clone ND028673B-2Russ. Field data collected over a 2-year period and used in the QTL analyses included tuber length–width and width–depth ratios that were obtained using a digital caliper. The width–depth ratio provided an assessment of the “flatness” of a tuber, which is of importance in potato processing. To cross-validate the accuracy and differences among tuber shape measurement methods, a trained evaluator also assessed the identical tubers based on 1–5 scale (compressed to long) visual assessment method. Furthermore, the weights of analyzed tubers and specific gravities were also collected during the phenotyping process for each mapping clone. A major tuber shape QTL was consistently observed on chromosome 10 with both the length–width ratio and visual assessments. On chromosome 4, a significant QTL for tuber shape from the visual assessment phenotypic data was also detected. Additionally, a tuber shape-related QTL on chromosome 6 was also detected from the length–width ratio data from 2020. Chromosome 2 was also identified as having a significant QTL for the width–depth ratio, which is of importance in influencing the flatness of a tuber. One significant QTL for tuber weight (i.e., tuber size) was observed on chromosome 5, and a significant QTL for specific gravity was found on chromosome 3. These significant and major QTL should be useful for developing marker-assisted selection for more efficient potato breeding.

薯块形状、大小与比重是褐皮商品薯类重要的农艺性状，对薯条等加工食品的品质、一致性与产品出成率具有显著影响。因此，通过数量性状基因座（quantitative trait locus/loci, QTL）分析鉴定与这三个性状相关的遗传区域，是后续开发用于马铃薯育种项目的标记辅助选择技术的关键环节。
本研究以两个褐皮亲本‘Palisade Russet’与育种克隆株ND028673B-2Russ杂交获得的190个个体组成的四倍体作图群体为材料开展QTL分析。研究通过两年时间采集田间数据用于QTL分析，所采集的数据包括使用数显卡尺测得的薯块长宽比与宽深比。其中宽深比可用于评估薯块的“扁平程度”，这一指标对马铃薯加工具有重要意义。
为交叉验证薯块形状测量方法的准确性与差异，训练有素的评估人员还采用1~5级（扁平至长形）的视觉评估法对同一批薯块进行评级。此外，在每个作图克隆株的表型鉴定过程中，还采集了供试薯块的重量与比重数据。
本研究检测到多个与薯块性状相关的QTL位点：在10号染色体上，通过长宽比与视觉评估两种方法均稳定检测到了主效薯块形状QTL；在4号染色体上，通过视觉评估的表型数据同样检测到了与薯块形状相关的显著QTL；此外，通过2020年的长宽比数据，在6号染色体上检测到了与薯块形状相关的QTL。2号染色体上同样存在与宽深比相关的显著QTL，该位点对薯块扁平程度具有重要调控作用。在5号染色体上检测到了与薯块重量（即薯块大小）相关的显著QTL，而3号染色体上则存在与比重相关的显著QTL。上述效应显著的主效QTL可用于开发标记辅助选择技术，以推动更高效的马铃薯育种工作。