Heat and Drought Stress Impact on Phenology, Grain Yield, and Nutritional Quality of Lentil (Lens culinaris Medikus)

Lentil (Lens culinarisMedikus) is a protein-rich cool-season food legume with an excellent
source of protein, prebiotic carbohydrates, minerals, and vitamins. With climate change,
heat, and drought stresses have become more frequent and intense in lentil growing
areas with a strong influence on phenology, grain yield, and nutritional quality. This study
aimed to assess the impact of heat and drought stresses on phenology, grain yield, and
nutritional quality of lentil. For this purpose, 100 lentil genotypes from the global collection
were evaluated under normal, heat, and combined heat-drought conditions. Analysis
of variance revealed significant differences (p < 0.001) among lentil genotypes for
phenological traits, yield components, and grain quality traits. Under no stress conditions,
mineral concentrations among lentil genotypes varied from 48 to 109mg kg−1 for iron
(Fe) and from 31 to 65mg kg−1 for zinc (Zn), while crude protein content ranged from
22.5 to 32.0%. Iron, zinc, and crude protein content were significantly reduced under
stress conditions, and the effect of combined heat-drought stress was more severe
than heat stress alone. A significant positive correlation was observed between iron
and zinc concentrations under both no stress and stress conditions. Based on grain
yield, crude protein, and iron and zinc concentrations, lentil genotypes were grouped
into three clusters following the hierarchical cluster analysis. Promising lentil genotypes
with high micronutrient contents, crude protein, and grain yield with the least effect of
heat and drought stress were identified as the potential donors for biofortification in the
lentil breeding program.