Landraces of Barley Exhibit Superior Drought Resistance: Insights from Agro-Morphological and Physiological Analysis

Barley is a marginalized crop subjected to several types of abiotic stress but need to intensify for future climate smart crop. This study investigated the drought resistance of barley landraces focusing on agro-morphological and physiological traits under controlled drought conditions. The experiment employed a two-factorial completely randomized design (CRD) with 14 barley landraces (of which 8 completed the maturity period examination) subjected to drought stress at three growth stages (CRI, tillering, and grain filling). Key parameters such as SPAD values (chlorophyll content), tiller number, and yield attributes were measured and analyzed using drought tolerance indices. Fourteen genotypes were initially tested, of which six failed to reach maturity; eight genotypes completed the full growth cycle and were used for yield and stress index analysis. Results revealed significant genotypic variation in drought response. Eight landraces exhibited higher SPAD values under drought, indicating better photosynthetic retention. Notably, AFU202501 demonstrated high yield stability (Stress Tolerance Index, STI = 1.782) under both stress and non-stress conditions, while Saptari Local showed exceptional drought avoidance (low Stress Susceptibility Index, SSI = −0.068) through early maturity and minimal yield reduction. In contrast, genotypes like Muktinath and NGRC 6010 were highly sensitive to drought, with significant yield losses (49–87%). Physiological traits such as chlorophyll retention and phenological plasticity (e.g., accelerated maturity under stress) were critical for drought adaptation. The findings highlight the potential of landraces like AFU202501 and Saptari Local as genetic resources for breeding climate-resilient barley varieties. The study underscores the importance of integrating traditional landraces into modern breeding programs to enhance food security in drought-prone regions.