Agromorphological Characterization and Marker–Trait Associations in Groundnut for Drought Tolerance

In Sudan, ~70% of groundnut ( Arachis hypogaea L.) production is by smallholder farmers under rainfed conditions, making yields highly vulnerable to drought. Developing drought‐tolerant cultivars adapted to local agroecologies is therefore a priority. This study evaluated 47 groundnut genotypes alongside 3 farmer‐preferred cultivars (Sodari, Tozi, and Kiriz) as checks under well‐watered and drought‐stressed conditions at Damazin Research Station Farm over two seasons, using a split‐plot design with three replications. Traits recorded included days to 50% flowering, days to maturity, plant height, and pod and seed yield per plant. Results showed significant ( p ≤ 0.001) effects of genotype, water regime, season, and their interactions among traits. Drought stress caused a slight delay in flowering and maturity, reduced plant height, and decreased pod and seed yields by 17% and 25%, respectively. Principal component analysis (PCA) highlighted yield‐related traits as major contributors to phenotypic variation and identified promising drought‐tolerant or drought‐adapted candidates, notably ICGV89242‐F2B2‐B1‐B1‐B‐B, ICGV94198, and ICGV92186. Among the checks, Sodari and Kiriz showed consistent performance. Preliminary single‐marker analysis detected suggestive candidate associations of PM183 with leaf area, PM375 with chlorophyl content, and PM384 with days to maturity ( β  = −3.230, p = 0.012, R ²  = 11.2%); none remained significant after Benjamini–Hochberg correction. Given the small sample size, these associations are preliminary and require validation in larger, independent populations. Nevertheless, integrating phenotypic and molecular approaches may facilitate identification of promising drought‐adapted groundnut germplasm; multilocation field trials are needed before recommendations are extended to Sudan’s rainfed agroecologies.