Diversity analysis of provitamin A maize inbred lines using single nucleotide polymorphism markers

The success of a breeding programme can be determined by the level of genetic diversity that exists among breeding materials. This study was carried out to (i) determine the level of genetic diversity that exist among the collection of tropical provitamin A maize inbred lines and (ii) evaluate the genetic structure and divergence of provitamin A maize inbred lines. Forty-six advanced provitamin A inbred lines obtained from the International Maize and Wheat Improvement Centre (CIMMYT) and International Institute of Tropical Agriculture (IITA) were genotyped using 3047 single nucleotide polymorphism (SNP) markers. Genotyping was done following an Illumina Infinium HD Assay Ultra protocol. Eight six percent of the SNPs were polymorphic with the mean polymorphic information content of 0.36. Cluster analysis displayed two distinct clusters. The average pairwise genetic distance among the inbred lines was 0.60. The average gene diversity was 0.359. Variation was partitioned into among individuals (78%), among populations (12%) and within individuals (10%). Overall results suggest the inbred lines are genetically diverse. The key implication of this study is that selection should be done from genetically diverse inbred lines in order to exploit heterosis when developing hybrids.