Developing N use efficient potato varieties requires exploring the genetic basis of nitrogen use efficiency (NUE) and associated agronomic and physiological traits. In order to identify QTLs for NUE and NUE-related traits, and to determine the relationships between the traits and QTLs in potato, a diploid potato mapping population (CxE) was evaluated in the field in Ethiopia under low and high N fertilizer levels. QTL detection was performed using interval mapping and multiple QTL mapping (MQM). A total of 52 putative QTLs were identified for ten traits, of which 28 QTLs were detected under low N availability while the remaining 24 QTLs were detected under high N conditions. Several QTLs were location and N level specific, suggesting the presence of QTL x environment interaction. A region on linkage group V (21-38 cM) accumulated the largest number of QTLs. This region coincides with the earliness locus encoded by the CDF1 gene, suggesting that earliness has a profound influence on NUE. A putative second QTL region on linkage group V located 20 cM from the earliness locus (38-56 cM) and a region on linkage group IV (60-72 cM) might be useful other regions to focus on, for NUE improvement in potato. To verify the stability of the identified QTLs and to use these for the detection of possible candidate genes, further multi-environment trials with larger population size may be required.

中文翻译：

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二倍体马铃薯群体中与氮素利用效率和相关性状相关的QTL的鉴定

开发氮素有效利用的马铃薯品种需要探索氮素利用效率（NUE）的遗传基础以及相关的农艺和生理特性。为了鉴定NUE和与NUE相关的性状的QTL，并确定性状与QTL之间的关系，在埃塞俄比亚田间在低氮和高氮水平下对二倍体马铃薯作图种群（CxE）进行了评估。使用间隔映射和多重QTL映射（MQM）进行QTL检测。总共鉴定出52个针对10个性状的QTL，其中28个QTL在氮素利用率低的情况下被检测到，其余24个QTL在高氮条件下被检测。几个QTL具有位置和N级特定性，表明存在QTL x环境相互作用。连锁组V（21-38 cM）上的区域积累了最多数量的QTL。该区域与CDF1基因编码的早期位点重合，表明早期对NUE具有深远的影响。连锁组V的一个假定的第二个QTL区位于距早发基因座（38-56 cM）20 cM的位置，而连锁组IV（60-72 cM）上的一个区域可能是其他值得关注的区域，可提高马铃薯的NUE。为了验证已鉴定QTL的稳定性并将其用于检测可能的候选基因，可能需要进行更大种群规模的进一步多环境试验。连锁组V的一个推定的第二个QTL区位于距早发基因座（38-56 cM）20 cM的位置，而连锁组IV（60-72 cM）上的一个区域可能是其他值得关注的区域，可提高马铃薯的NUE。为了验证已鉴定QTL的稳定性并将其用于检测可能的候选基因，可能需要进行更大种群规模的进一步多环境试验。连锁组V的一个推定的第二个QTL区位于距早发基因座（38-56 cM）20 cM的位置，而连锁组IV（60-72 cM）上的一个区域可能是其他值得关注的区域，可提高马铃薯的NUE。为了验证已鉴定QTL的稳定性并将其用于检测可能的候选基因，可能需要进行更大种群规模的进一步多环境试验。