Genetic Diversity and Drought Tolerance Indices in Landraces of Lentil (Lens culinaris Medik.) Using Physiological Markers

Abstract

Genetic diversity and drought tolerance are critical traits for improving lentil productivity under water-limited conditions, particularly in semi-arid agroecosystems. This study characterizes the genetic variability and drought tolerance indices among diverse landraces of lentil (Lens culinaris Medik.) using key physiological markers. Field experiments were conducted under both well-watered and drought-stressed conditions to evaluate genotype performance across contrasting moisture regimes. Physiological parameters such as relative water content, chlorophyll stability index, membrane stability, canopy temperature, and photosynthetic efficiency were measured alongside yield and biomass attributes. Drought tolerance indices, including stress tolerance index, yield stability index, and drought susceptibility index, were computed to identify resilient genotypes. Results revealed substantial genetic variability among landraces, with certain genotypes exhibiting superior physiological adaptation under drought conditions, characterized by higher water retention, stable chlorophyll content, and efficient photosynthetic activity. These genotypes also demonstrated better yield stability and lower susceptibility to drought stress compared to others. The integration of physiological markers with drought indices proved effective in identifying tolerant landraces with potential for cultivation in stress-prone environments. The study highlights the importance of utilizing indigenous genetic resources to enhance crop resilience and sustain productivity under climate variability. While analytical tools were used to assess genetic and physiological responses, the primary focus remains on crop improvement and agronomic adaptation. These findings provide valuable insights for breeding programs and farmers aiming to select drought-tolerant lentil varieties that ensure stable yield and efficient resource use in water-scarce agricultural systems.