水、旱稻氮高效QTL定位及其表达的遗传背景效应研究

Effects of Genetic Background on Expression of QTL for Nitrogen Efficiency in Irrigated Rice and Upland Rice

【目的】挖掘不同来源水、旱稻亲本的氮高效优良等位变异,研究氮高效QTL表达的遗传背景效应,为水稻氮高效QTL的精细定位和分子标记辅助选择育种提供理论依据。【方法】以旱稻IAPAR-9分别与水稻辽盐241和秋光杂交而创制的2个F7粳粳交重组自交系群体为试验材料,进行了水稻全生育期氮素利用率及其相关性状的QTL定位分析。【结果】在"IAPAR-9/辽盐241"重组自交系群体中检测出31个氮素利用率相关性状的QTL,分布于除第6、第7和第10染色体外的9条染色体上,氮素利用率相关QTL成簇分布区间有9个;在"IAPAR-9/秋光"重组自交系群体中检测出33个氮素利用率相关性状的QTL,分布于除第4和第10染色体外的10条染色体上,氮素利用率相关QTL成簇分布区间有7个。【结论】氮素利用率相关性状QTL的表达,受遗传背景影响较大。2个群体均检测到的氮素利用率相关性状QTL的成簇分布区间,即第2染色体上的RM3421—RM5404区间以及第8染色体上RM8264所在的相邻区间,可能对水稻氮高效分子标记辅助选择育种有重要利用价值。

【Objective】 Elite alleles of nitrogen efficiency derived from different irrigated rice and upland rice were detected, and the effects of genetic background on expression of quantitative trait locus （QTL） were analyzed for providing a theoretical basis for fine mapping and molecular marker-assisted breeding of nitrogen efficiency in rice. 【Method】 QTL of some traits associated with nitrogen utilization efficiency were identified using two japonica × japonica recombinant inbred lines （RILs）. The first RILs was from the cross IAPAR-9 （upland rice）/Liaoyan241 （irrigated rice）, and the second RILs was from the cross IAPAR-9/Akihikari （irrigated rice）. 【Result】 A total of 31 QTLs referring some traits correlated with nitrogen utilization efficiency in the first RILs were detected on all chromosomes except chromosomes 6, 7 and 10. QTLs controlling different traits were mapped on the same or adjacent intervals, forming 9 clusters in rice chromosomes. In the second RILs, 33 QTLs for some traits associated with nitrogen utilization efficiency were found on all chromosomes except chromosomes 4 and 10, forming 7 clusters in rice chromosomes. 【Conclusion】 Genetic background had a significant impact on QTL expression of some traits associated with nitrogen utilization efficiency. The interval, RM3421-RM5404, in chromosome 2 and the adjacent interval with RM8264 in chromosome 8, where QTLs underlying traits associated with nitrogen utilization efficiency stably expressed across different genetic backgrounds, may be beneficial to MAS for nitrogen efficiency in rice.