Drought resilience in indigenous maize germplasm links productivity and nutritional quality with kernel lipid metabolism

Drought is a major constraint on maize productivity and kernel quality, particularly in rainfed agroecosystems, where locally adapted germplasm may provide valuable genetic resources for climate-resilient agriculture. This study examined drought responses in indigenous maize germplasms from Mizoram, Northeast India, focusing on root anatomy, plant productivity, leaf metabolic responses, yield attributes, nutritional quality, and kernel oil characteristics. We initially screened indigenous germplasms under well-watered (100% field capacity, FC) and drought (35% FC) conditions, selecting MZM-8 and MZM-17 as contrasting drought-sensitive and drought-resilient germplasms, respectively, with HQPM-1 (an improved quality protein hybrid maize) as a check germplasm. The experiment was conducted at 35, 70, and 105 DAG (days after germination), representing vegetative, reproductive, and post-reproductive stages of maize development. Drought stress substantially suppressed plant growth, biomass accumulation, and yield-related attributes, with greater reductions in MZM-8. In contrast, HQPM-1, followed by MZM-17, maintained comparatively higher growth and yield under water scarcity. Root anatomical analysis further revealed drought-induced structural adjustments, with HQPM-1 and MZM-17 exhibiting comparatively better maintenance of root anatomical characteristics under water deficit. GC-MS profiling of leaf samples revealed distinct metabolic reprogramming among germplasms, including alterations in fatty acids and other stress-responsive metabolites. Drought-induced changes in kernel nutritional attributes and oil quality were also germplasm-dependent, with HQPM-1 and MZM-17 demonstrating greater stability of important quality traits. Overall, the differential responses of MZM-8 and MZM-17 demonstrate substantial genetic variation in drought resilience among maize germplasms of Mizoram, highlighting their potential for climate-resilient maize improvement and sustainable production under increasing water scarcity.