## 4 Discussion
### Genetic Variability Vs. Physiological and Yield Characteristics
Cultivars such as \"Vineta\", \"Oberon\", \"Satina\", \"Jelly\", and \"Mondoe\" represent promising candidates for further selection and the development of cultivars with heightened photosynthetic capabilities. This, in turn, has the potential to bolster crop yields and overall efficiency. This assertion carries both scientific and practical significance, underscoring the pivotal role of genetics in shaping the photosynthetic efficiency of the studied potato cultivars. Additionally, it paves the way for future research endeavors and the refinement of cultivation methodologies. Photosynthetic efficiency (Qn): Several cultivars including 'Vineta', 'Oberon', 'Satina', 'Jelly', and 'Mondoe' showed significantly higher photosynthetic efficiency compared to the other cultivars. Three homogeneous groups of cultivars were distinguished based on Qn values. Therefore, the genetic characteristics of the studied potato cultivars played a significant role in determining the various fluorescence parameters related to photosynthetic efficiency. These findings may be valuable for understanding and selecting cultivars with desirable photosynthetic traits for potato cultivation (Table 3). The high photosynthetic efficiency of cultivars such as 'Vineta', 'Oberon', 'Satina', 'Jelly', and 'Mondoe' may mean that these cultivars have a better ability to convert sunlight into chemical energy through photosynthesis. Dividing cultivars into three groups based on Qn may suggest that different cultivars have different mechanisms for regulating photosynthesis or different levels of efficiency, depending on their genetic characteristics. The results obtained in the conducted research suggest that differences in the genetic characteristics of potato cultivars affect their ability to carry out photosynthesis and adapt to changing light conditions. These differences may result from different mechanisms of transmitting light energy to chlorophyll, the efficiency of the photosynthesis process, and the ability to adapt to changes in the light environment. The values of these parameters may be useful when selecting potato cultivars for cultivation, especially in the context of photosynthesis efficiency and yield [42]. The results obtained from the conducted research indicate that genetic factors primarily determine the key physiological indicators, which include: Fm, Fv/Fm, Fo\({}^{\prime}\), Fm\({}^{\prime}\), Y, Qp and Qn as well as the tuber yield, their dry weight, starch as well as dry matter yield and starch yield. The relationships regarding physiological indicators confirm the work of [PERSON] et al. [14], [PERSON] et al. [15], [PERSON] et al. [16], and [PERSON] and [PERSON] [47], and the varietal relationships regarding tuber yield, dry matter yield and starch were confirmed by the research of [PERSON] et al. [17], [PERSON] and [PERSON] [18], [PERSON] et al. [20], [PERSON] and [PERSON] [22], [PERSON] et al. [42]. The study of the relationship between genetic diversity, physiological indicators, and tuber yield, DM yield, and starch yield will provide a better understanding of the mechanisms affecting plant performance. This knowledge is essential for improving agriculture, environmental protection, food security, and adaptation to changing global conditions [59; 60; 61]. Understanding the genetic variability of potato traits is critical to developing effective breeding strategies, improving crop yields, food quality, and adapting crops to changing environmental conditions [60; 61; 62; 63; 64]. To compare the variability of the physiological indicators and economic characteristics of potatoes, the coefficient of variation (V) was used (Table 6). Its lower value indicates the greater stability of a given feature, as it represents less dispersion of results around the average value. When analyzing the assessed physiological indicators of the studied potato cultivars, their generally small variability was observed, especially in the case of the maximum chlorophyll fluorescence (Fm) efficiency.