The physiological responses of potato (Solanum tuberosum L) cultivars to soil drought at the tuberization phase and their impact on agronomically important traits were investigated in potted plants under semi‐controlled conditions. Genotype‐dependent responses of potato to water deficiency were evaluated on two pairs (tolerant/sensitive) of Polish cultivars. Each pair of cultivars had a similar genetic background but was extremely different in terms of drought tolerance evaluated on the basis of loss of tuber yield under field conditions. The results clearly indicate different mechanisms of tolerance to water deficiency and the ability to recover from soil drought in two tolerant but genetically unrelated cultivars. When subjected to soil drought, the cultivar Gwiazda had low rates of transpiration and photosynthesis and low levels of stomatal conductance due to hypersensitivity to ABA, but its maximal photochemistry efficiency and PSII performance index were unchanged. Another strategy was displayed by the dehydration‐avoidant cultivar Tajfun, which kept the stomata partially open. Thus, the plants were able to retain a relatively high rate of photosynthesis over transpiration. The parameters measured for cultivar Tajfun for photosynthesis and transpiration were the same after plant rewatering, similar to the control plants. This was not the case for the cultivar Gwiazda. The ability of plants to regenerate after soil drought relief appears to be a good indicator of potato susceptibility to soil drought and allows the yield of potato tubers to be predicted. The physiological traits identified in closely related potato cultivars but differed in their drought tolerance seem to be useful for genetic engineering and breeding programmes.

The potato has been a widely used vegetable crop in temperate countries for a long time. Its consumption and the area of its cultivation has increased significantly over the past decades in the tropics and subtropics as well. The main problems of potato producers in the tropics and subtropics are the unsatisfactory quality of seed potatoes, mainly derived from the informal seed supply system, and the insufficient availability and high cost of certified seed potatoes. The hope for improving this situation can be the application of soil-less technologies for minituber production under controlled conditions. This publication focuses on important advantages of the aeroponic system in the production of pre-basic seed potatoes in the tropics and subtropics. It also highlights some deficiencies that can be overcome with the involvement of several actors in the potato industry, including local universities and the private sector. It emphasizes that innovative aeroponic installations are an opportunity to increase the production of high-quality seed potatoes in the countries of the tropics and subtropics, which, in many cases, will result in less dependence on expensive imported seed potatoes, often from a different climate zone. The introduction of aeroponic installations conserves the shrinking natural soil and water resources and contributes to their protection.

Cereal plants under abiotic or biotic stressors to survive unfavourable conditions and continue growth and development, rapidly and precisely identify external stimuli and activate complex molecular, biochemical, and physiological responses. To elicit a response to the stress factors, interactions between reactive oxygen and nitrogen species, calcium ions, mitogen-activated protein kinases, calcium-dependent protein kinases, calcineurin B-like interacting protein kinase, phytohormones and transcription factors occur. The integration of all these elements enables the change of gene expression, and the release of the antioxidant defence and protein repair systems. There are still numerous gaps in knowledge on these subjects in the literature caused by the multitude of signalling cascade components, simultaneous activation of multiple pathways and the intersection of their individual elements in response to both single and multiple stresses. Here, signal transduction pathways in cereal plants under drought, salinity, heavy metal stress, pathogen, and pest attack, as well as the crosstalk between the reactions during double stress responses are discussed. This article is a summary of the latest discoveries on signal transduction pathways and it integrates the available information to better outline the whole research problem for future research challenges as well as for the creative breeding of stress-tolerant cultivars of cereals.

The presented study was aimed at investigating the variability for drought tolerance among potato cultivars. To achieve this, the stability of drought tolerance of potato cultivars under different water regime conditions was inspected during 11 years of consecutive experiments. The data on 50 potato cultivars’ responses to drought stress, based on the morphological features of plants, i.e., leaf and stem mass and size of the assimilation area, have been collected. The tuber yield, as well as calculated plant tolerance indexes and Climatic Water Balance for each growing season, were analyzed. The studied cultivars were later assigned into one of three tolerance groups for soil drought. The highest linear relationship was found between the mass of leaves and stems and the tuber yield but was found too weak to raise any conclusions. Thus, the ensemble learning models have been evaluated and returned better performance results, and the final classifier is the implementation of extreme gradient boosting. The final classifier of the 96.7% accuracy, which used several measured potato parameters (Relative yield decrease, Stem mass, Maturity, Assimilation area, Leaves mass, Yield per plant, calculated Climatic water balance, and indices: MSTI and DSI) that could distinguish the different tolerance groups were evaluated in the study.

Potato (Solanum tuberosum L.) is considered a drought-sensitive crop species, although cultivar-dependent differences in tolerance have been described. The extent of drought-induced tuber yield decreases is considered the main criterion for potato tolerance to drought. In this study, eighteen closely related potato cultivars were subjected to drought stress, and among them, two groups with contrasting drought tolerance phenotypes were distinguished (tolerant: Sebago, Katahdin and Cayuga; susceptible: Sequoia and Carpatin). Photosynthesis is the most important primary metabolic process that determines the yield of potato crops and is also strongly affected by drought. The photosynthetic parameters of these two groups of potato cultivars were assessed by measuring chlorophyll a fluorescence. Drought-induced changes in the examined parameters were observed in both groups of cultivars, but the changes in the drought-sensitive group were relatively much more pronounced. The tolerant and sensitive groups significantly differed in terms of most photosynthetic parameters. Principal component analysis (PCA) revealed differences in the responses of the examined potato cultivars and separated tolerant cultivars from sensitive ones, similar to the criterion of the relative decrease in tuber yields. These results suggest that chlorophyll a fluorescence may serve as a useful tool for estimating the level of tolerance to drought stress in potato.