Abstract: Quantitative trait loci (QTLs) for rice panicle length under two nitrogen levels were mapped on to the molecular marker linkage map by using a rice doubled haploid population derived from a cross between IR64 and Azucena. Two QTLs for panicle length, one on chromosome 1 and the other on chromosome 4 were detected at high N level, while five QTLs for panicle length were identified at low N level. The interaction between N levels and QTL for rice panicle length was therefore suggested. Based on this interaction and different response to low N stress between two parents, it was supposed that some QTLs only detected at low N level might be related with the ability of rice to tolerate low N stress.

Key words: rice, panicle length, molecular marker, quantitative trait loci

摘要： 在水稻(IR64×Azucena) DH群体中应用分子标记连锁图，对不同供氮水平下的穗长性状进行QTL区间作图分析。在高氮水平下检测到控制穗长的QTLs 2个，分别位于第1和第4染色体上；在低氮水平下检测到5个穗长QTLs，其中3个分别位于第1、4和6染色体上，2个位于第3 染色体的不同部位，说明穗长QTL与供氮水平之间可能存在交互效应。基于这种互作效应及研究中观察到的两供试亲本对低氮胁迫的耐性差异，推测仅在低氮水平下检测到的穗长QTLs可能跟水稻对低氮胁迫耐性有一定的关联。

关键词: 水稻, 穗长, 分子标记, 数量性状位点