Genetic Diversity of Maize ( Zea mays L.) Landraces from Cameroon and Democratic Republic of Congo Using Phenological, Biometrical and Yield Components

Abstract

To address the knowledge gap in Cameroonian maize landraces, this study aimed to determine the nature and magnitude of genetic variability, heritability, genetic advance, and principal component analysis of yield-related traits (e.g., yield and yield component traits) in landraces adapted to the Cameroon bimodal rainforest agroecology zone. Twenty traits, including vegetative, phenological, and yield-related traits, were analyzed. Descriptive statistics and the analysis of variance showed significant variability (p < 0.05) among the landraces for most traits. Plant height varied largely, with a mean of 240.39 cm and a CV of 18.49%, while root collar diameter and leaf area showed CVs of 21.26% and 24.88%, respectively. Both male and female at 50% flowering had low CVs, specifically 5.11% and 4.15%, respectively. Plant height, ear height, leaf area, root collar diameter and total number of panicle branches significantly contributed to PC1, indicating their major role in overall morphological diversity. Hierarchical clustering analysis on principal components (HCPC) grouped the 36 landraces into three distinct clusters. Broad-sense heritability ( H ²) ranged from 0.01 for maximum germination time to 0.69 for germination latency time, indicating diverse genetic control in the traits. Multivariate analysis of variance (MANOVA) showed significant differences among landraces when considering all traits simultaneously (Wilks’ Lambda = 1.44e−10, p = 1.595e−06). Shannon-Weaver diversity indices across the 36 landraces ranged from 1.815 to 2.141, indicating varying levels of morphological diversity. Further studies involving biochemical and molecular markers are recommended for deeper characterization.