利用1 041个SNP位点对51份玉米自交系进行基因型分析，最小等位基因频率平均值为0.359，多态性信息含量（PIC）的变化范围为0.186～0.375，平均值为0.345；Roger’s遗传距离的变化范围为0.009 2～0.704 1。根据Roger’s遗传距离信息，利用NJ聚类法将51份玉米自交系划分为7个杂种优势群，包括改良瑞德群、瑞德群、兰卡斯特群、旅大红骨群、塘四平头群（或称黄改群）、P群和糯质群，划分结果和系谱来源基本一致。7个杂种优势群的群体间遗传距离变化范围为0.285 0～0.432 1，瑞德群和改良瑞德群之间的遗传距离最近；旅大红骨群和P群之间的遗传距离最远。

The genotype of 51 maize inbred lines was analyzed by 1 041 SNP marker locus, the average MAF was 0.359, the PIC ranging from 0.186-0.375, average PIC was 0.345, the Roger's genetic distance ranging from 0.009 2-0.704 1. According to information of Roger's genetic distance, NJ clustering method was used to divide the 51 maize inbred lines into seven heterotic groups. It includes Improved Reid, Reid, Lancaster, LudaRed Cob, Tang-Si-Ping-Tou(or ImprovedHuangzao4), Waxy groups. The clustering results were almost consistent with the pedigree information. The changing rang of genetic distance among seven heterotic groups was from 0.285 0 to 0.432 1, in which the genetic distance between Reid group and Improved Reid group was the most nearest, and the genetic distance between Luda Red Cob group and P group was the farthest.

北京市科技计划课题（D131100000213002）、国家科技支撑项目（2011BAD35B09）