Using Physiological Parameters to Select Potato Genotypes Tolerant to High Temperature

As a crop adapted to high-altitude and cool climates, potato suffers substantial yield losses when grown in tropical regions exposed to high temperatures. Developing genotypes tolerant to heat stress is therefore a key strategy to mitigate these adverse effects. The aim of this study was to evaluate elite clones and cultivars from the potato breeding program of Embrapa, Brazil, regarding their capacity to withstand high-temperature stress, and to identify physiological patterns that can accelerate the breeding process. The experiment was conducted in growth chambers in a randomized block design with three replicates. After planting, tubers were maintained under control conditions (14-24 °C) until the onset of tuberization. At this stage, a group of plants was subjected to 14 days of heat stress (24-34 °C). Physiological evaluations were carried out on the last day of stress. Plants were then returned to control temperature conditions, where they remained until harvest at 75 days after planting, when biometric measurements related to growth and yield determination were performed. All genotypes exhibited reductions in photosynthesis under heat; however, the cultivar ‘Granola’ as the most promising, combining high photosynthetic tolerance with multiple defense mechanisms to maintain yield.