Analysis of Genetic Structure and Relationships of Maize Inbred Lines in China

Based on molecular marker data from 112 microsatellites, the genetic structure of 97 maize inbred lines was analyzed using distance-based and model-based clustering methods. The dendrograms produced by both methods showed similar categories but the model-based dendrogram sorted the uncertain lines in the distance-based cluster tree, which provided reasonable explanation of the category. The analysis of genetic structure and model-based cluster showed that the 97 inbred lines were classified into 4 subpopulations, which were known as Reid, Lüda Red Cob (LRC), PB, and Sipingtou (SPT). Many inbred lines in a subpopulation contained certain genetic component from other subpopulations. According to Nei's genetic distance, the Reid subpopulation was the closet to the LRC subpopulation and the farthest to the SPT subpopulation. For simplifying the heterotic groups, the subpopulations Reid and LRC could be integrated into one group, or even Reid, LRC, and PB could be integrated into one group.