中文摘要：

【目的】对不同浓度磷、钾处理下小麦苗期氮养分效率相关性状进行QTL分析,以深入理解磷、钾与氮养分效率的相互关系,为氮营养相关性状的图位克隆及分子标记辅助选择育种奠定基础。【方法】采用苗期液培试验,以＂川35050×山农483＂组合衍生的小麦重组自交系群体（131个株系）为研究材料,设置了中磷中钾（MPMK）、高磷（HP）、低磷1（LP1）、低磷2（LP2）、低磷3（LP3）,高钾（HK）、低钾1（LK1）、低钾2（LK2）、低钾3（LK3）共9个处理,对不同磷、钾处理下的氮养分效率相关性状进行研究,并结合分子标记遗传图谱,从整个基因组水平对与小麦苗期氮养分效率相关的10个性状进行QTL定位及遗传分析。【结果】不同处理下的10个性状共检测到137个QTL,位于除3D外的20条染色体上,大部分QTL（89.05%）仅在单一处理下被定位到,有3个QTL（QRnue-1A.2、QSnue-1A.1和QTnue-1A.1）可在至少4个处理中被检测到,有5个QTL（QRnue-1A.1、QTnue-1A.1、QSnc-4A、QRnc-6A.3和QSnue-6B）可同时在低磷和低钾环境中被检测到。本研究还检测到至少包含3个以上QTL的QTL簇17个,分别位于1A、1B、2B、2D、3A、3B、4A、4B、5D、6A、6 B、6 D和7 A染色体上,共涉及6 6个Q T L,占Q T L总数的4 8.1 8%。其中,有5个Q T L簇仅与特定磷、钾处理有关,大多数QTL簇均同时定位了不同磷、钾处理的不同性状,许多QTL簇位点还与前人定位的生物量、产量及其他养分有关。【结论】磷、钾的供应能够显著影响小麦苗期对氮素的吸收利用及其相关QTL的表达。影响苗期小麦氮养分效率相关性状的QTL大多数仅在特定处理下被检测到,但大多数QTL会形成QTL簇,构成了控制氮养分效率的QTL热点,许多热点区域也与前人定位的许多成株期性状如生物量、产量及其他养分效率有关,这些QTL/基因密集区域及其特点的发现,为我们深入理解小麦氮养分效率?

英文摘要：

【Objectives】The objective of this study was to detect quantitative trait locus（QTL） for N use efficiency related traits at the seedling stage of wheat under different levels of phosphorus（P） and potassium（K）treatments. The results will deepen our understanding of the relationship between N and P/K, and this knowledge could be applied for map-based cloning and marker assisted selection（MAS） in wheat breeding. 【Methods】Population employed for QTL analysis was a set of 131 RILs derived from a Chuan 35050 × Shannong 483 cross.The 131 RILs and their parental lines were grown under hydroponic culture in greenhouse. Nine treatments were designed. The concentrations of the applied P and K treatments were as follows： moderate P and K（MPMK）, high P（HP）, low P1（LP1）, low P2（LP2）, low P3（LP3）, high K（HK）, low K1（LK1）, low K2（LK2） and low K3（LK3）. Combined with an enriched genetic map, we conducted research on the N use efficiency traits under different P and K treatments in order to map the QTLs（quantitative trait loci） related to N use efficiency of 10 traits at the wheat seedling stage and to conduct genetic analysis at the whole genome level. 【Results】 A total of 137 QTLs for the 10 seedling traits were detected on 20 chromosomes, with the exception of 3D. Of these QTLs, 122（89.05%） were detected in only one treatment. Three relatively high-frequency QTLs（QRnue-1A.2,QSnue-1A.1 and QTnue-1A.1） were detected in four treatments at least. Five QTLs（QRnue-1A.1, QTnue-1A.1, QSnc-4A, QRnc-6A.3 and QSnue-6B） were detected in both the low P and low K treatments. Seventeen important QTL clusters（C1-C17） containing at least three or more traits which involved 66 out of 137 QTLs（48.18%） were mapped on chromosomes 1A, 1B, 2B, 2D, 3A, 3B, 4A, 4B, 5D, 6A, 6B, 6D and 7A. Most QTL clusters were detected in both P and K treatments, while five QTL clusters only associated with specific phosphorus or potassium treatments. Many QTL cluster sites in this