## 1 Introduction
The evaluation of the sowing value of stored and treated seed potatoes is mainly limited to field tests based on the measurement of plant height and tuber yield. The published data do not provide information that would indicate independence of the changing parameters of seed potato quality from selected plant physiological functions, which could be proposed as useful indicators of their seeding value, as previously developed for apple, willow, vegetable species, sorghum, and Jerusalem artichoke [15; 16; 17; 18; 19; 20; 21; 22]. The proper understanding of the physiology and its optimization requires a precise physiological \"calibration\" of the behavior of seed potatoes and the use of appropriate markers that would indicate the quality of seed potato [23; 24]. Their use in laboratory conditions allows to quickly evaluate the impact of seed potato treatments on the development, health, and physiological activity of stems and roots, changes in soil structure, and forecasting plant growth in the field. The traditional methods used to identify pathogen species involve the microscopic inspection of morphological characteristics. Taxonomic keys and descriptions have been developed and widely used for identifying potatoes. Moreover, a loop-mediated isothermal amplification (LAMP) method has been implemented for the rapid and accurate detection of pathogens in plants [25; 26]. However, a significant constraint in LAMP assays lies in the design of proper primers. In addition, polymerase chain reaction (PCR) has been used as a tool to detect and quantify the causal agents of late blight (_Phytophthora infestans_), pink rot (_Phytophthora erythroseptica_), leak (_Pythium ultimum_), dry rot (_Fusarium sambucinum_), and soft rot (_Pectobacterium caroroorum_) in potato tubers [27; 28]. To detect all possible fungal and oomycete pathogens causing pink rot, watery wound rot, and gangrene in potatoes, specific primers, and probes have been designed for PCR assays [29]. In our research, we decided to detect volatile organic metabolites produced by potato pathogens by HS-SPME-GC-MS and try to connect these data with potato physiology. The advantage of using GC-MS in the metabolomic evaluation of VOC is related to the reliability, efficiency, reproducibility, and selectivity of the method. It is able to measure hundreds of compounds due to high chromatographic resolution. Rich libraries for GC-MS are another positive aspect of using this method for VOC analysis [30]. Headspace solid-phase microextraction (HS-SPME) is used for complex matrices analysis. It does not destruct the analyzed sample and does not require the use of organic solvents [8]. Previously, gas chromatography-mass spectrometry (GC-MS) has been used for profiling VOCs in order to differentiate potato tubers infected by rot pathogens [31] and to select tomato varieties with resistance to Fusarium wilt disease [32]. Another method for the detection of different types of volatile organic compounds is the employment of an electronic nose [33]. The method of operation of this device, which is increasingly used, is based on mimicking the sense of smell [34]. The aim of the study was to investigate the effect of seed potato phytopathogens on the production of volatile organic compounds (VOC) and on selected growth parameters, physiological activity, and yielding of plants, in order to determine their usefulness as markers in the assessment of the development of potatoes subjected to disease protection treatments.