Wild Relatives Enhance Genetic Resources for Maize (Zea mays ssp. mays) Improvement through Diversity Analysis

Deciphering genetic diversity is essential for identifying promising parents in maize hybridization programs. A clear understanding of population structure and genetic variability underpins the success of pre-breeding efforts. Wild relatives of maize harbor unique traits, highlighting their importance as valuable genetic resources. In this study, morphological and molecular diversity, along with population structure, were evaluated in 30 maize germplasm, including landraces, elite inbred lines, and wild relatives such as Coix , teosinte, and Tripsacum . Among the seven studied traits—plant height, stalk width, number of tillers, chlorophyll content, leaf protein content, flag leaf length, and flag leaf width—chlorophyll content contributed most to divergence, followed by number of tillers.Wild relatives outperformed inbreds for mean value of most of the traits, offering valuable alleles for maize improvement. Based on morphological traits, k-means clustering and principal component analysis the germplasm were grouped into four clusters. Wild relatives grouped in separate clusters (II, III and IV) from the cultivated (Cluster-I), indicating their potential value for hybridization-based improvement. Molecular diversity analysis using 84 polymorphic SSR markers divided the germplasm into three clusters, corroborated by population structure analysis. Fixation index (Fst) values revealed moderate to low differentiation in subpopulations 2 and 3 (0.1443 and 0.1323), suggesting a high degree of admixture. Overall, the study reveals substantial genetic diversity within the evaluated germplasm, emphasizing its potential for utilization in pre-breeding programs. These results support tapping wild alleles with strategic domestication to boost maize diversity, productivity, biomass accumulation and adaptability.