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

This study investigated the drought resistance of barley landraces compared to modern cultivars, focusing on agro-morphological and physiological traits under controlled drought conditions. The experiment employed a two-factorial completely randomized design (CRD) with 17 barley landraces subjected to drought stress at three growth stages (tillering, jointing, and heading). Key parameters such as SPAD values (chlorophyll content), tiller number, root–shoot length, and yield attributes were measured and analyzed using drought tolerance indices. Six landraces reached maturity. Results revealed significant genotypic variation in drought response. Six landraces exhibited higher SPAD values under drought, indicating better photosynthetic retention. Notably, NBD 4 demonstrated high yield stability (Stress Tolerance Index, STI = 1.782) under both stress and non-stress conditions. At the same time, 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 susceptible 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 NBD 4 and Saptari Local as genetic resources for breeding climate-resilient barley varieties. Ths study underscores the importance of integrating traditional landraces into modern breeding programs to enhance food security in drought-prone regions.