Determination of morphological, physiological, and agronomical responses of potato genotypes to heat

In the era of global warming, breeding heat-resilient potato varieties is among the most critical goals in potato breeding. This study aimed to evaluate the effect of elevated temperature on the morphological, physiological, biochemical and agronomic characteristics of potato genotypes under field conditions. The field experiments were conducted using a split-plot design with two temperature treatments (ambient and elevated temperature) as main plots and 29 genotypes as sub-plots, each with three replications, in 2022 and 2023. An open-sided polyethylene high tunnel was constructed adjacent to the open field to increase the temperature. This setup raised the ambient temperature by approximately 6–10 °C from planting to harvest, varying depending on the date and time of day. The results indicate elevated temperature effectively promoted potato genotypes' morphological, physiological and antioxidant enzyme activities. Different stress indices were calculated and a cluster analysis was performed to identify high-yielding and tolerant genotypes. Heat-tolerant potato genotypes possess an efficient defence mechanism against reactive oxygen species (ROS) by enhancing the antioxidant enzyme activity under heat stress. This study demonstrates that constructing open-sided clear polyethylene greenhouses to create a warmer environment is an effective strategy for selecting heat-resilient potato genotypes under field conditions.