## 4 Discussion
### Genetic Variability Vs. Physiological and Yield Characteristics
The coefficient of variation for Fm was only 12.3%, which proves the high stability of this feature, as the measurement results were consistently similar. However, for qP, the coefficient of variation was 19.38%, which indicates a greater variability of results for this feature. The designation Qp refers to the quantum yield of Photosystem II photochemistry. It is a measure of the efficiency of photosynthesis in Photosystem II, which is one of two types of chloroplast photosystems responsible for capturing light energy and converting it into chemical energy, which is in turn used to produce glucose and other organic compounds. Qp measures the ratio of the amount of light energy entering the photosynthesis process to the amount of light energy used to produce chemical energy (in triggering photosynthesis). This means that Qp determines how efficiently Photosystem II converts light into chemical energy. A higher value indicates a higher efficiency of photosynthesis, which means that more light energy is converted into chemical energy, which in turn can contribute to more efficient plant growth. The analysis of the coefficient of variation allows for a better understanding of the degree of variability of the examined features and their possible stability in the tested sample. A similar opinion on this matter has been expressed by [PERSON] et al. [16] and [PERSON] [39]. The tested potato physiological parameters showed variability, but usually low variability. The coefficient of variation was lower for traits that showed greater stability, suggesting that these traits had less variability among the tested genotypes. The practical implications of these relationships for plant breeding, cultivar selection, and agricultural practices concern genetic variability in potatoes, which will enable breeders to more closely monitor the stability and variability of traits in the cultivars studied. The selection of genotypes with stable traits can lead to the development of more productive, resistant, and environmentally adapted potato cultivars. Selecting cultivars with stable characteristics for cultivation can help in the more efficient use of resources such as water, fertilizers, and energy. Appropriate adaptation of agricultural practices to the genetic characteristics of plants may contribute to the creation of sustainable agriculture [44; 55; 62]. Genes involved in photosynthesis such as genes encoding enzymes involved in converting light into chemical energy can influence the physiological indicators related to photosynthesis. Changes in these genes may affect the efficiency of photosynthesis, and consequently crop yield [44]. Genes that control plant hormone signaling and regulation can influence genotypic diversity and physiological indicators. Plant hormones affect developmental processes, stress responses, and other aspects of physiology, which may affect the yield characteristics [60; 62]. The genes regulating these metabolic pathways may affect the availability of nutrients and the efficiency of their use by plants [63; 64]. Genes responsible for regulating the development of roots, stems, leaves, and other plant organs can influence the plant's capacity to absorb water, nutrients, and the efficiency of photosynthesis [65]. These genes can interact with each other and with the plant environment, leading to changes in gene expression and metabolic function. These interactions may affect physiological indices and yield characteristics depending on the environmental conditions [62; 63; 64; 65]. Analysis of the genetic variability of potato traits could help identify cultvars more resistant to environmental stresses such as drought or cold. Cultivars with stable physiological indicators may be better able to survive in difficult conditions. Therefore, the analysis of the genetic variability of potato traits using the index of variation (V) has important implications for plant breeding, cultivar selection, and agricultural practices.