Integrative Screening of Maize Genotypes for Heat Tolerance Based on Biomass, NDVI, and Cell Membrane Thermostability Traits

Abstract

Heat stress is a major threat to sustainable maize production especially during the spring season as high temperature causes tassel blast, pollen sterility, poor seed setting and barren cobs. The adoption of heat stress mitigation strategies is the pre-requisite to reduce income risks for farmers and to ensure food security under changing climatic scenarios. Therefore, this study was designed to characterize maize germplasm under heat stress. For this purpose, a set of 125 indigenous inbred lines were screened for key heat-responsive traits i.e., cell membrane thermostability (%), shoot and root weight (g), NDVI and chlorophyll content (SPAD units). Cell membrane integrity is linked to improved chlorophyll synthesis, enhanced photosynthetic activity and higher biomass production under heat stress. The inbred lines DR-02, DR-150, DR-93, DR-139, EL-147, EL-234, and EL-36 were selected as heat tolerant, and EL-267, EL-94 and UML-1 were selected as heat sensitive lines. Incorporation of the identified heat-tolerant maize inbred lines with high cell membrane thermostability (CMT) and other key traits together could be valuable for developing future climate-resilient maize cultivars.