Drought stress induced by polyethylene glycol (PEG) on germination and seedling stage in maize landraces from Yucatan, Mexico: Drought stress in maize landraces

Abstract

Drought stress negatively affects germination, vegetative growth, biomass production, and yield traits in maize (Zea mays L.). In this study, we investigate the effects of osmotic stress induced by polyethylene glycol (PEG) solutions on germination, early seedling growth traits, and the physiologic response of ten maize genotypes in Yucatan, Mexico. Additionally, drought tolerance indices were calculated and used to differentiate drought-tolerant genotypes. The data were examined by two-way analysis of variance and multivariate analysis. The results showed that PEG treatments significantly reduced germination and retarded seedling growth of maize genotypes. The physiological response of maize genotypes was also affected. Under drought stress, maize genotypes showed reduced carbon assimilation, stomatal conductance, and transpiration, but increased water use efficiency. Additionally, variability was observed in drought tolerance traits among different maize genotypes. According to PCA analysis based on variation in drought tolerance indices, three maize genotypes are drought-tolerant, including NTR, NTA, and NTB. These genotypes are suitable for cultivating areas where water availability is limited and for selecting tolerant genotypes to drought in breeding programs