A Novel Heterosis Utilization Pattern in Huang-Huai-Hai Maize Production

Abstract The Huang-Huai-Hai region is a critical maize production area in China, essential for national food security. However, its reliance on limited heterosis utilization patterns threatens future food stability. This study presents a comprehensive genetic analysis of 368 maize hybrids, uncovering a novel heterosis pattern, termed "MY73". Through principal component analysis (PCA) and population structure analysis, we identified nine distinct heterosis patterns—X/Reid, X/TSPT, Reid/TSPT-LRC, Reid/TSPT, BSSS/NSS, X/TSPT-LRC, X/Reid-PB, Reid/PB, and "MY73" pattern—all of which showed high congruence with pedigree data. Linkage disequilibrium (LD) analysis revealed that the "MY73" pattern exhibits the most rapid LD decay, suggesting increased genetic diversity. Furthermore, by integrating the results of the Fst and XP-CLR analyses between the “MY73” pattern and the other patterns, we identified seven genomic regions specific to the “MY73” pattern: Chr.1: 275,178,001–275,181,000 bp; Chr.2: 31,120,001–31,140,000 bp; Chr.3: 191,560,001–191,580,000 bp; Chr.5: 72,063,001–72,066,000 bp; Chr.6: 49,120,001–49,140,000 bp; Chr.10: 48,180,001–48,200,000 bp; and Chr.10: 107,460,001–107,480,000 bp. The discovery of this pattern enhances the genetic resources available for heterosis utilization in maize breeding, providing new opportunities for developing high-density tolerant, high-yield maize cultivars and supporting sustainable maize production and food security.