Morphological Variation, Ecological Adaptation, and Folk Classification of Ethiopian Sorghum (Sorghum bicolor) Landraces: A Comparative Analysis of Statistical Clustering and Traditional Taxonomy

Abstract

Sorghum (Sorghum bicolor), a cornerstone of food security in Ethiopia, exhibits remarkable morphological diversity shaped by agroecological factors and traditional farming practices. This study investigates how altitude and environmental conditions influence morphological traits in Ethiopian sorghum landraces and evaluates the alignment between farmers’ folk classifications and statistical clustering methods. Using datasets from Abdi et al. (2002) and Teshome et al. (1997), we analyzed 14 qualitative traits—including panicle compactness, stalk juiciness, and grain color—across altitude gradients (1,500–2,000 m.a.s.l.) in North Shewa and South Welo. Canonical Discriminant Analysis (CDA) and hierarchical clustering were employed to derive statistical groupings, which were compared with traditional folk taxonomy. Results revealed altitude-driven trait adaptation: high-altitude landraces (>1,800 m.a.s.l.) predominantly exhibited compact panicles (33%) and non-juicy stalks (100%), likely mitigating frost risk, while lowland variants (<1,500 m.a.s.l.) displayed looser panicles (25%) and juicier stalks (54%) for drought resilience. Shannon diversity indices highlighted significant trait variation (mean H’ = 0.77), with peduncle shape being most diverse (H’ = 0.98). Statistical clusters aligned with farmers’ classifications in 72% of cases, particularly for races like Durra (compact panicles) and Caudatum (semi-compact panicles). Discrepancies arose in intermediate traits, underscoring the complementary roles of quantitative and traditional systems. This study pioneers an integrated classification framework merging statistical clusters (e.g., altitude-specific Durra) with folk taxonomy (e.g., drought-tolerant “Wegere”), offering actionable insights for conservation and breeding. Recommendations include prioritizing in-situ preservation of high-diversity ecotypes and participatory breeding programs leveraging farmers’ knowledge. By bridging quantitative analysis with indigenous wisdom, this work advances strategies to enhance sorghum resilience and sustain Ethiopia’s agro-biodiversity amidst climatic challenges.