Physiological Characterization in Some Groundnut Genotypes for Drought Tolerance

Abstract

Groundnut (Arachis hypogaea L.) is an important food and cash crop in Sudan, with approximately 70% of its production occurring under rainfed smallholder farming systems. However, productivity is severely constrained by recurrent drought, particularly during the reproductive stage. Identifying high-yielding and drought-tolerant genotypes adapted to local agro-ecological conditions is therefore essential for enhancing agricultural resilience and food security. This study evaluated 50 groundnut genotypes together with three farmer-preferred cultivars (Sodari, Tozi, and Kiriz) as checks under well-watered and drought-stressed conditions at Damazin Research Station (11°46′18.2″ N, 34°21′40.5″ E), Blue Nile Region, Sudan, during the 2016/2017 and 2017/2018 growing seasons. The experiment was conducted in the savannah agro-ecological zone using a split-plot design with three replications. Data were collected on leaf area index, chlorophyll content, root-to-shoot ratio, relative water content, 1000-seed weight, pod yield per plant, and seed yield per plant. Genotype, water regime, season, and their interactions significantly (P≤0.001) affected most of the evaluated traits. Drought stress reduced leaf area index, 1000-seed weight, pod yield per plant, and seed yield per plant by approximately 4.7%, 22.8%, 16.8%, and 24.8%, respectively, while chlorophyll content, root-to-shoot ratio, and relative water content increased by approximately 7.4%, 24.3%, and 13.4%, respectively. Several genotypes demonstrated superior and relatively stable performance under drought stress, particularly ICGV89242-F2B2-B1-B1-B-B, C97B-38-2, and ICGV-94198, while the farmer-preferred cultivars Kiriz and Sodari also performed well. These genotypes represent valuable genetic resources for breeding high-yielding, drought-tolerant, and climate-resilient groundnut cultivars adapted to drought-prone environments in Sudan.