Genetic Properties Of 240 Chinese Maize Inbred Lines Revealed By High-density SNP Markers

Maize(Zea mays L.) is an important crop which serves as food and forage. It plays an significant role in agricultural and economic development. Characterization of the genetic properties of maize inbred lines is beneficial not only for increasing knowledge of genetic diversity, but also for maize breeding. In the present study, a panel of 240 maize inbred lines commonly used in China, including three foundation parents Dan340, Mol7, and Huangzao4, and their derivatives, was genotyped using the MaizeSNP50 BeadChip, which contains 56,110 SNP markers. The results were as fellows:A total of 40,757 SNPs with unique physical positions were successfully recalled in this panel with an average coverage of 50 Kb per SNP. Five subgroups including Lan, LRC, PB, Reid, and SPT were inferred using 4,000 SNPs with MAF≥ 0.200, which were largely consistent with the pedigree information for these 240 inbred lines.With a cutoff value of r~2< 0.100, LD decay distances along the 10 chromosomes of maize ranged from 397 Kb to 819 Kb, with an average of 643 Kb.A subtotal of 26,35, and 23 IBD segments, which were longer than both the average LD decay distance on the corresponding chromosomes and the local LD decay distance of r~2< 0.100, were identified in the Dan340, Huangzao4, and Mo 17 derivatives, respectively. Three lower peaks for Tajima’s D overlapped with three major QTL (qkrn7, scmvl, and qHS2.09) in these derivatives.In summary, elucidating the genetic properties of this panel provides information for investigating the genetic architecture of agronomic traits and heterotic grouping during maize breeding.