中文摘要：

近等基因系的选育是分子遗传图谱构建、数量性状基因定位及分子标记辅助育种的重要基础之一。利用分子标记辅助目标性状QTL前景选择及恢复轮回亲本基因组的背景选择,再结合表型选择获得了定位在水稻4号和6号染色体上的根基粗、千粒重2个主效QTL的近等基因系。其中有9个系入选旱田根基粗主效QTL brt4.1的近等基因系,根基粗的表型值为1.07～1.16mm,较轮回亲本越富提高6.11%～15.18%,平均遗传背景恢复率达97.22%;千粒重主效QTLtgw6.1的近等基因系有11个系入选,千粒重的表型值为21.25～26.25g,较轮回亲本越富的增幅7.05%～32.16%,平均遗传背景恢复率95.97%。

英文摘要：

The development of near-isogenie lines （NILs） is one of the important foundations for the establishment of molecular linkage map, the mapping of quantitative trait loeus（QTL） and molecular marker-assisted selection （MAS）. In the present study, NILs for two major QTLs of basal root thickness （BRT） and 1000-grain-weight （TGW） were obtained through the foreground selection for the target QTL, the background selection for the genome of the recurrent parents of 3 backeross populations（ BC1F1, BC2F1 and BC3F1 and phenotypie selection for the population of BC3F2. There were 9 BRT QTL-NILs with BRT ranges of 1.07～1.16 mm, over the recurrent parent by 6.11%～15.18% and an average recovering ratio of genetic background （RRGB）of 97.22%; eleven NILs of TGW QTL with ranges of 21.25～26.25 g, over the recurrent parent by 7.05%～32.16% and 95.97% of RRGB.