以生产上广泛种植的玉米杂交种豫玉22的亲本自交系87-1和综3为受体亲本，以糯质、抗病性较好的玉米自交系衡白522为供体亲本，采用回交和自交的方法，结合SSR分子标记辅助选择，分别构建了以87-1和综3为背景的衔接式玉米单片段导入系群体，并对其遗传背景、导入片段大小、数目和覆盖率等进行了评价。结果表明，87-1背景的导入系群体导入了40个供体片段，片段长度介于0.03~342.8 cM，平均长度为91.1 cM，导入片段总长为3 643.9 cM，覆盖率为48.9%；综3背景的导入系群体导入了78个供体片段，片段长度介于0.03~343.4 cM，平均长度为75.5 cM，导入片段总长为5 895.2 cM，覆盖率为79.2%。
Currently, a widely adopted strategy to estimate the position and effect of a mapped QTL more accurately is to create a new mapping population by crossing nearly isogenic line (NIL). In such a population, because of the absence of other segregating genetic background, the target QTL becomes the major genetic source of variation. Under such conditions, the QTL is considered as Mendel factor, and the distances between a QTL and the nearby molecular markers can be estimated more precisely. However, as a premise to perform the strategy, NILs that differ only at a short chromosome segment harboring QTL must be produced by marker assisted backcross introgression of one QTL allele into one or both parental genetic backgrounds. To develop two set of NILs covering whole genome of maize respectively, 87-1 and Zong 3(two parental lines of an elite maize hybrid Yuyu 22), and Hengbai 522(a waxy corn line derived from a local variety with short plant stature and disease resistance), were employed in the study. Two populations of link-up single segment introgression lines (SSILs) were developed with 87-1 and Zong 3 as the recurrent parents, Hengbai 522 as donor, respectively through 3–4 cycles advanced backcross. Foreground and background of populations were screened by SSR markers in each cycle of backcross. Genetic evaluation showed that 40 and 78 segments from the donor line were introgressed into 87-1 and Zong 3 SSILs, respectively. In population of 87-1 SSILs, the average length of a single introgressive segment was 91.1 cM, varying from 0.03 to 342.8 cM. The total segment length was 3 643.9 cM with coverage of 48.9% of chromosomes. In population of Zong 3 SSILs, the largest segment was 343.4 cM with an average and a total length of 75.5 cM and 5895.2 cM, respectively, and with the coverage of 79.2% of chromosomes. These developed SSILs could be widely used in fine mapping of QTLs and functional genomics researches of maize.
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