Abstract: To lower the high amylose content(AC) of an elite indica rice restorer line 057,four indica varieties(R367,91499,Yanhui 559 and Hui 527) with low amylose content were used as donor and backcrossed with recurrent parent 057 respectively,and their backcrosses were identified using a molecular marker(PCR-AccⅠ).There existed significant differences in AC(among) three Wx genotypes(GG,TT,GT).Amylose contents in rice grain were more than 20% in GG genotype,17.71% to 28.48% in GT genotype and less than 18% in TT genotype.It was suggested that the PCRAccⅠ molecular(marker)-assisted selection for AC of rice grain was usable and reliable,and the AC of 057 had been lowered successfully.

Key words: molecular marker-assisted selection, indica rice, amylose content, breeding, grain quality

摘要： 以4种低直链淀粉含量（AC）的籼稻品种(R367、91499、盐恢559、恢527)作优质基因的供体，以产量配合力较强的三系籼稻恢复系057为受体轮回亲本，对高AC值的057进行回交改良。在回交改良中利用分子标记对控制AC值的基因型进行选择，并对分子标记鉴定的Wx基因3种表达类型（GG、TT、GT）植株稻米的AC值进行测定分析。结果显示，GG型植株的稻米AC值高于20%；GT型的变化较大，为17.71%~28.48%；TT型的小于18%。经最小显著差数法（LSR）检验，3种基因型间AC差异达极显著水平。表明这种分子标记对稻米AC值的辅助选择是可靠有效的。通过分子标记辅助选择有效降低了057的AC值。

关键词: 分子标记辅助选择, 籼稻, 直链淀粉含量, 育种, 稻米品质