Drought significantly constrains common bean (Phaseolus vulgaris L.) production worldwide, and as climate change intensifies, projections indicate a subsequent reduction in yield. This study aimed to identify drought-resilient genotypes among twenty common bean lines in Chile under two water regimes: regular irrigation and terminal drought stress. The research was conducted over two seasons in south-central Chile. Drought significantly reduced grain yield (22.7%), aboveground biomass (37%), harvest index (19.5%), the number of grains per pod (61.3%), and hundred-grain weight (10.1%). Genotypes 452, 473, and 483 exhibited minimal yield reductions (<11%) and maintained stable physiological performance, including higher quantum yield of photosystem II and efficient photoprotective mechanisms (increased ΦNPQ) under stress. In contrast, sensitive genotypes like Blanco Español showed marked yield loss (54%) and lower photosynthetic efficiency. Chlorophyll retention emerged as a key trait for identifying high-yielding, drought-tolerant genotypes. Drought also accelerated crop maturation in susceptible genotypes, compromising yield potential. These findings highlight the importance of integrating agronomic, phenological, and physiological traits in breeding programs to develop drought-adapted varieties. The tolerant genotypes offer valuable genetic traits to improve drought resilience and contribute to food security in the face of climate change.
Rice is a staple food grown worldwide. While white rice varieties have been extensively studied, there is limited information on the performance of pigmented rice genotypes and their tolerance to water deficit. This study evaluated nineteen black rice genotypes and one white cultivar over three years under contrasting water regimes: traditional flooding and non-flood irrigation (NFI). Genotype–environment interactions and their impact on agronomic, yield, and grain quality traits were assessed. Black genotypes under NFI showed reduced flowering and grain quality. The average yield was 31% lower than the white cultivar. Significant genetic correlations were found between grain yield and days to anthesis (DSA), grain weight (TGW), chalkiness (CHA), and translucency (TRAN), with high broad-sense heritability (H2 > 0.9). Most traits exhibited high heritability (H2 > 0.7), indicating strong genetic stability. Grain yield (GR) was highly and negatively correlated with percent sterility (PS) (r = −0.84) and had a heritability of 0.76. Environmental conditions significantly influenced yield, confirming the potential for selecting water stress–tolerant genotypes. These findings provide valuable insights into black rice breeding and optimizing water management practices to support sustainable production. To our knowledge, this study is the first to evaluate the performance of a diverse set of black rice genotypes across multiple seasons under contrasting water regimes in a Mediterranean environment.