Unveiling the Genetic Diversity of Aerial Yam (Dioscorea bulbifera L.): Morphological Insights for Sustainable Crop Improvement

Abstract

Background: Genetic diversity is a cornerstone of sustainable agriculture, enhancing the resilience and productivity of crops in changing environments. Aerial yam (Dioscorea bulbifera L.), a tuber crop primarily grown in tropical and subtropical regions, has the potential to contribute to food and nutritional security. Despite its importance, the genetic diversity of aerial yam remains largely unexplored, limiting its conservation and genetic improvement. Aim: The aim of this study was to assess the genetic diversity of 20 D. bulbifera landraces collected from six Nigerian states (Cross River, Akwa Ibom, Enugu, Abia, Benue, and Ebonyi) using morphological traits as markers. Study Design: A randomized complete block design (RCBD) was used, with three replicates. Place and Duration of Study: The experiment was conducted at the experimental field of University of Calabar, Calabar, Nigeria, from March 2023 to February 2024. Methodology: Bulbils from 20 D. bulbifera landraces, were planted on March 19, 2023 on a single-row plot. Key morphological traits; vine length, leaf area, and bulbil production, were recorded and analyzed for ANOVA, principal component analysis (PCA), cluster analysis, and path coefficient analysis. Results: Significant variations (p < 0.05) were observed for all traits, indicating genetic diversity among the landraces. PCA identified three principal components accounting for 57.25% of the total variability, with root length, leaf area, and bulbil count being the most influential traits. Cluster analysis grouped the landraces into two clusters with no strict adherence to geographic origin, suggesting possible gene flow. There is a positive relationship between vine length and leaf area (r = 0.349, p < 0.05), while leaf length had the strongest direct effect on bulbil production. Conclusion: The findings highlight significant genetic variability within D. bulbifera, providing a basis for breeding and conservation. This study emphasizes the crop’s potential for food security and sets the stage for integrating molecular techniques alongside morphological assessments.