Genetic diversity and heterotic pattern analysis in sweet maize inbred lines and a preliminary GWAS in F₁ hybrids using a low-cost SNP chip

抄録

This study proposes a genomic-assisted breeding framework for sweet maize using a low-density SNP chip. After genotyping 95 inbred lines (68 retained with 8,484 SNPs), we assessed genetic diversity and population structure, revealing four distinct clusters. Using this information, 25 representative lines were crossed in incomplete diallel crossing designs to generate 102 F₁ hybrids for phenotyping. An exploratory genome-wide association study (GWAS) on this F₁ population identified 15 candidate loci for agronomic traits. Trait-specific positive correlations were observed between parental genetic distance and hybrid performance. This integrated strategy supported the release of four elite cultivars. The GWAS findings are preliminary and require independent validation due to the modest population size. Nevertheless, this work demonstrates that integrating low-density SNP data for diversity analysis and heterotic grouping effectively guides parental selection and accelerates cultivar development.