*2.2. DNA Isolation and Genotyping Analysis*

For each accession, total genomic DNA was isolated from bulked leaf composites from 15 seedlings at two weeks old according to the DArT protocol (https://www.diversityarrays.com/orderinstructions/ plant-dna-extraction-protocol-for-dart/). The quality of each DNA sample was visualized by electrophoresis on 0.8% agarose gel, and the purified DNA was further quantified using a nano-drop spectrophotometer (Thermo Scientific, Wilmington DE, USA). Certified DNA samples were then sent to the Integrated Genomic Service and Support (IGSS) genotyping platform, Nairobi, Kenya, for genotyping. High-throughput genotyping was conducted in 96 plex DArTseq protocol, and SNPs were called using the DArT's proprietary software, DArTSoft, as previously described [22]. Reads and tags found in each sequencing result were aligned to the *Zea mays* L. genome reference, version *AGPV3* (B73 Ref-Gen v4 assembly) [23].
