The mechanism of potato (Solanum tuberosum L.) thermotolerance has been the focus of intensive research for many years because plant growth and tuber yield are highly sensitive to heat stress. However, the linkage between the aerial and belowground parts of potato plants in response to high temperatures is not clear. To disentangle this issue, the aerial and belowground parts of the heat-resistant cultivar Dian187 (D187) and the heat-sensitive cultivar Qingshu 9 (Qs9) were independently exposed to high-temperature (30 °C) conditions using a special incubator. The results indicated that when the belowground plant parts were maintained at a normal temperature, the growth of the aerial plant parts was maintained even when independently exposed to heat stress. In contrast, the treatment that independently exposed the belowground plant parts to heat stress promoted premature senescence in the plant’s leaves, even when the aerial plant parts were maintained at a normal temperature. When the aerial part of the plant was independently treated with heat stress, tuberization belowground was not delayed, and tuberization suppression was not as severe as when the belowground plant parts independently underwent heat stress. Heat stress on the belowground plant parts alone had virtually no damaging effects on the leaf photosynthetic system but caused distinct tuber deformation, secondary growth, and the loss of tuber skin colour. Transcriptome analysis revealed that the treatment of the belowground plant parts at 30 °C induced 3361 differentially expressed genes in the Qs9 cultivar’s expanding tubers, while the D187 cultivar had only 10,148 differentially expressed genes. Conversely, when only the aerial plant parts were treated at 30 °C, there were just 807 DEGs (differentially expressed genes) in the D187 cultivar’s expanding tubers compared with 6563 DEGs in the Qs9 cultivar, indicating that the two cultivars with different heat sensitivities have distinct regulatory mechanisms of tuberization when exposed to heat stress. The information provided in this study may be useful for further exploring the genes associated with high-temperature resistance in potato cultivars.

Sulfur and phosphorus are important plant nutrients required for potato growth, influencing the synthesis of primary metabolites that serve as the material foundation of potato flavor quality. However, little is known about the effects of sulfur and phosphorus application on potato tuber flavor. This study experimentally compared the effects of the individual and combined application of phosphorus and sulfur fertilizers on the flavor of potato tubers. The research examined the sensory characteristics of flavor under various fertilization methods, investigated changes in the types and contents of volatile flavor compounds, and conducted analyses on flavor precursor compounds. The experimental results showed that the application of phosphorus and sulfur fertilizers, either individually or in combination significantly increased the content of linoleic acid and linolenic acid. After the combined application of phosphorus and sulfur fertilizers, the starch and the reducing sugar content also significantly increased. (E,E)-2,4-Nonadienal and Decanal are closely correlated with fatty acid content. Dimethyl sulfide and Trimethyl sulfide contents are significantly related to methionine content. This also significantly enhances the fatty taste characteristics of the tubers but weakens the potato flavor characteristics. Hence, the application of phosphorus and sulfur can affect the accumulation of primary metabolic products in tubers, thereby affecting flavor quality. Compared with the individual application of phosphorus or sulfur fertilizers, when phosphorus fertilizer is applied at 180 kg·ha⁻¹ and sulfur fertilizer at 90 kg·ha⁻¹ in combination, it can further enrich the roasted flavor characteristics of potatoes and maximize the enhancement of potato flavor quality. This provides valuable theoretical support for achieving high-quality agricultural development.