Molecular characterisation of maize hybrids

Abstract

Despite the huge diversity of maize germplasm, modern maize breeding programme and agricultural practices decrease the diversity of modern hybrids. Genetic characterization of maize hybrids allows knowledge of the genetic relationship among them, thus preventing the risk of increasing uniformity. Because of their high reproducibility, informativeness and easey application of microsatelites are the most frequently used molecular markers in maize genetic diversity studies. The aim of our work was to evaluate genetic diversity of maize hybrids by SSR markers and compare results with their pedigre information. Sixteen polymorphic SSR (Simple Sequence Repeats) markers were used to characterize 14 maize (Zea mays L.) hybrids belonging to different breeding programs and FAO groups (from 300 to 800). A total of 53 alleles were found, ranging from two to four alleles. Genetic similarities were calculated in NTSYSpc2 program package using Jaccard’s coefficient based on binary data (presence or absence of alleles). The highest value of genetic similarity was 0.80 between H1 and H2, while the lowest value (0.26) was found between H12 and H13. Cluster analysis was done by unweighted pair group method (UPGMA) on the basis of genetic similarity matrix. Dendrogram analysis grouped maize hybrids in one cluster (most of the analyzed genotypes), one smaller cluster and one branch. The results revealed genetic heterogeneity between analyzed maize hybrids.