Developing PCR-Based SNP Markers for Distinguishing Korean Waxy Corn F1 Hybrids

Single nucleotide polymorphisms (SNPs) are abundantly and evenly distributed throughout the genomes of most plant species. These markers have become popular for use in genetic research in many crops. SNP markers can be used to screen maize cultivars rapidly during the early growth stages. In this study, to develop additional SNP markers for maize, we chose 20 SNP sites per chromosome from the maizeGDB website (www.maizegdb.org) and designed primers with two base pair mismatches using Primer Designer 4 based on putative SNP sites of the B73 genome sequence. The polymerase chain reaction (PCR) products ranged from 200 to 500 bp in size, whereas no PCR product was detected when the SNP site was present in Korean waxy corn. Using nine Korean commercial F1 hybrids of waxy corn, including Chalok 1, Chalok 4, Ilmichal, Eolrukchal 1, Heukjinjuchal, Hayanchal 95, Mibaekchal, Mibaek 2, and Miheukchal, we selected 16 primer sets showing clear bands or no bands. Based on cluster analysis, we confirmed that the nine Korean waxy corn hybrids could clearly be distinguished. The SNP marker sets are easy to utilize through simple PCR and agarose gel electrophoresis. These results suggest that analysis using the SNP marker set designed in this study would be faster, cheaper, and more reproducible than that using other genotyping tools, such as cleaved amplified polymorphic sequence markers, which require the use of restriction enzymes.