Evaluation of Morpho-physiological Traits, Chemical Quality Parameters and Drought Tolerance Indices Inbidi Tobacco (Nicotiana tabacum L.) Germplasm Lines

Abstract

Drought resilience is a critical breeding objective in bidi tobacco (Nicotiana tabacum L.) due to the crop’s economic significance and its predominance in moisture limited regions. To assess genetic variation for yield and drought tolerance, 100 diverse bidi tobacco germplasm lines were evaluated at the Regional Agricultural Research Station, Nandyal, Acharya N.G. Ranga Agricultural University, during 2022–23 under both normal and rainfed conditions. Substantial genetic variability was observed among the lines for yield and associated morpho-physiological and chemical quality traits, indicating a broad genetic base for selection. Drought stress markedly reduced plant growth, leaf area and cured leaf yield due to impaired photosynthetic efficiency and water status, while enhancing nicotine accumulation. Among the evaluated lines, NyBD 71, NyBD 62, NyBD 73, NyBD 74 and NyBD 78 demonstrated superior performance across environments, with higher cured leaf yield, mean productivity and geometric mean productivity, reflecting yield stability and drought resilience. Additionally, NyBD 90 and NyBD 89 exhibited lower stress susceptibility and greater yield stability indices, indicating better adaptability to moisture stress. These identified genotypes, combining high productivity, physiological efficiency and desirable biochemical composition, constitute valuable genetic resources for developing drought tolerant, high yielding bidi tobacco cultivars suited to rainfed conditions.