Physiological Characterization in Some Groundnut Genotypes for Drought Tolerance
Amin A. Ahmed Ibrahim *
Department of Agronomy, Faculty of Agriculture, University of Khartoum, P. O. Box 32. Shambat, Sudan and Oil Crop Research Centre, Damazin Research Station, Damazin, Agricultural Research Corporation, Sudan.
Seif Eldin M. Gasim
Department of Agronomy, Faculty of Agriculture, University of Khartoum, P. O. Box 32. Shambat, Sudan.
Ahmed H. Abuassar
Oil Crop Research Center, Agricultural Research Corporation, P.O. Box 126, Wad Medani, Sudan.
Mayada M. Beshir
Biotechnology and Biosafety Research Corporation, Agricultural Research Corporation, P.O. Box: 30, Shambat, Sudan.
*Author to whom correspondence should be addressed.
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.
Keywords: Groundnut, Arachis hypogaea L., drought tolerance, drought stress, water deficit, physiological traits, chlorophyll content, relative water content, root-to-shoot ratio, drought-tolerance indices, seed yield.