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利用ＲＡＰＤ分子标记技术研究了我国４６个重要玉米自交系及部分优良自选系相互之间的遗传距离与其杂交组合杂交优势的关系。结果表明，应用ＲＡＰＤ分子标记测得的自交系间遗传距离与其杂交优势显著正相关，即玉米自交系之间遗传距离越大，其杂交种子粒产量越高，杂交优势就越强。测得我国２８个玉米主栽单交种双亲间遗传距离平均值为６１。根据不同遗传距离，组配７２个单交组合，在单株潜力粒重＞２００ｇ的２９个组合中遗传距离≥６０者占９３１％，而在遗传距离＜６０的４０个组合中，单株潜力粒重＞２００ｇ者只占５％。故遗传距离６０可作为预测强杂交优势的临界值。
RAPD molecular markers were used to study the relationship between the genetic distances among 46 important maize inbred lines and some elite autonomous lines in China and the heterosis of their hybrid combinations. The results showed that the genetic distance between inbred lines detected by RAPD markers was significantly and positively correlated with their heterosis. That is, the greater the genetic distance between maize inbred lines, the higher the hybrid seed yield and the stronger heterosis. The average genetic distance between parents of 28 single maize cultivars in China was 61. According to different genetic distances, 72 combinations of single crosses were found, with genetic distance≥60 accounting for 931% of the 29 combinations with single grain weight> 200g. In 40 combinations with genetic distance <60 In the combination, the potential single plant weight> 200g accounted for only 5%. Therefore, the genetic distance of 60 can be used as a predictor of the predominance of strong hybrids.