10th U6+ Consortium of African Universities International Conference

Sorghum (Sorghum bicolor L.) is a critical cereal crop for food security in sub-Saharan Africa due to its tolerance to drought and low-phosphorus environments. However, phosphorus deficiency in heavily weathered tropical soils remains a major impediment to sorghum productivity in the region, especially among the resource-constrained farmers. Cultivation of varieties with enhanced phosphorus acquisition efficiency under limiting conditions presents a sustainable approach to improve productivity and reduce reliance on external fertilizer sources. The objective of this study was to identify elite sorghum genotypes with improved phosphorus acquisition efficiency. Fifteen genotypes were evaluated based on root morphological traits associated with P acquisition efficiency using a hydroponic nutrient solution system at adequate and low phosphorus supply. There was significant (p ≤ 0.05) variation among genotypes in primary root length, total root length, root depth, surface area, root volume, root tip number, network area, convex area, solidity, lower root area, and root-to-shoot biomass ratio. The best adapted genotypes including E95A, N57, N68, T53b, T30b, C26, E118, Gadam and Sila, had higher root length, root surface area, root volume, root tip abundance, and an increase accumulation of root biomass in low phosphorus. This paper examines the plasticity of the root system architecture traits in response to low phosphorus and their reliability as phenotypic indicators to identify phosphorus-acquisition efficient sorghum genotypes. The traits will be integrated into breeding programs to accelerate the development of nutrient-efficient and climate-resilient sorghum cultivars. Such cultivars have the potential to increase productivity in phosphorus-deficient environments, enhance food security, and fuel sustainable agricultural development in sub-Saharan Africa.