Stress-Responsive Physiological and Molecular Traits Governing Drought Tolerance in Hot Pepper Hybrids

Praneetha Subramanyam; Poobalan  V; Ajay Raja A; Subhavyuktha S

doi:10.56093/ijas.v96i9.175769

Authors

Praneetha Subramanyam Department of Vegetable Science, HC & RI, TNAU, Coimbatore
Poobalan V Assistant Professor, Vanavarayar Institute, Affliated to Tamil Nadu Agricultural University, Coimbatore - 641003, India
Ajay Raja A Research Scholar, Department of Vegetable Science, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore - 641003, India
Subhavyuktha S Research Scholar, Department of Vegetable Science, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore - 641003, India

https://doi.org/10.56093/ijas.v96i9.175769

Keywords:

Drought stress, Physiological traits, Molecular markers, EST, Chilli hybrids

Abstract

Drought stress is a major abiotic constraint affecting growth, yield, and productivity of hot pepper (Capsicum annuum L.), particularly under rainfed cultivation. The present investigation was undertaken to identify reliable physiological, biochemical, and molecular indicators governing drought tolerance in hot pepper hybrids. Twenty-eight F₁ hybrids developed from seven lines and four testers, along with their parents, were evaluated under irrigated and drought stress conditions using a split-plot design. Key physiological and biochemical traits, including relative water content, chlorophyll stability index, soluble protein content, proline accumulation, catalase activity, and nitrate reductase activity, were recorded to assess stress responses. Multivariate analysis through principal component analysis was employed to identify major contributors to drought tolerance. Molecular validation of drought tolerance was performed using drought-responsive expressed sequence tag markers. Drought stress resulted in a general decline in physiological performance; however, F₁ hybrids exhibited superior tolerance compared to parental lines for most traits. Principal component analysis revealed that proline content, catalase activity, soluble protein, and chlorophyll stability index were the major traits contributing to drought tolerance. Molecular characterization confirmed the presence of drought-tolerance alleles in all hybrids, validating their physiological performance. Among the hybrids, IC-119233 × Arka Lohit consistently showed superior performance under both stress and non-stress conditions. The integrated physiological and molecular approach proved effective in identifying drought-tolerant hot pepper hybrids, offering valuable insights for developing climate-resilient cultivars.

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