Abstract:

【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.

Key words: irrigated rice')">irrigated rice, upland rice, nitrogen efficiency, SSR marker, quantitative trait locus, genetic background