Ilze Skrabule

Different potato genotypes vary in nitrogen uptake and biomass production at different available nitrogen levels. In vitro experiments offer a controlled environment to further explore these variations. The study aimed to evaluate the morphological traits of various potato genotypes in a two-factorial experiment, analysing microplant responses depending on nitrogen availability in the growth medium in vitro. The study, conducted in 2022 in Priekuli, Latvia, tested 19 potato genotypes under varying nitrogen levels in an in vitro medium. The experiment was carried out in three time-shifted series each with four replications. The Murashige and Skoog basal medium used for the experiments included N concentrations of 60 mmol L⁻¹ (N60), 20 mmol L⁻¹ (N20), and 7.5 mmol L⁻¹ (N7.5). The morphological traits analyzed in the potato microplants included plant height, fresh weight (FW) and dry weight (DW) of the total plant, as well as FW and DW of the shoots and roots. Additionally, calculated traits included the root % share, root-to-shoot ratio and the nitrogen stress tolerance coefficient (NstC) of the genotypes. Results showed significant differences in biomass production between different N levels (p<0.05) as well as significant differences between genotypes grown under the same N level were identified. NstC differed between genotypes.

This two-year study assessed nitrogen use efficiency (NUE) and its effect on potato tuber protein concentration, focusing on crude protein concentration (CPC), crude protein yield (CPY), and patatin relative abundance (PRA) across 19 potato genotypes and four nitrogen management treatments (organic with no added fertilizers and three integrated treatments with N rates of 60, 120, and 180 kg ha⁻¹). Nitrogen availability significantly affected CPC, with the highest average CPC across genotypes being 10.7% at 180 kg ha⁻¹ and the lowest of 8.15% at 60 kg ha⁻¹. Certain genotypes consistently outperformed others in terms of CPC and/or CPY under varying nitrogen treatments. A significant negative correlation was found between CPC and NUE, and genotypes with higher NUE typically had lower CPC. A positive correlation between CPY and NUE was observed, with the highest CPY of 1.36 t ha⁻¹ at 120 kg N ha⁻¹ in 2020. This suggests that higher NUE genotypes are more efficient in protein production per unit area. PRA varied significantly among genotypes, ranging from 8.7% to 35.51%. Although the relationship between NUE and PRA was weak, the significant and negative correlation indicates that cultivars with high NUE could have low PRA and vice versa. The findings underscore the importance of genotype variability in the relationship between NUE and protein content in potato tubers.

Potato is one of the important crops worldwide, and cultivation requires a lot of resources and nitrogen (N) to ensure yield. This kind of growing technology can cause environmental pollution. It is necessary to optimize the management and use of potatoes with high nitrogen use efficiency (NUE) varieties as an alternative to the application of large amounts of fertilizers to improve the environmental impact of potato production without affecting yield and quality. The aim of this review is to find various morphological and physiological characteristics of the potato crop that can be used in potato breeding for NUE evaluation and to create new varieties with high NUE. Looking for traits such as yield, protein and starch content, each variety has its limits that can be affected by climatic conditions. Area Under Canopy Cover Progress Curve (AUCCPC) is potentially good for detecting NUE in field conditions. Nitrogen efficient genotypes tend to have early canopy development but a low amount of N in tubers. Due to different factors that can interact with genotypes under field conditions, the experiments in controlled conditions as in vitro system can be used for the investigation of genotypes in a short period. Under in vitro conditions, root development can be observed very well, which can usually be impossible in soil experiments.

In organic production of potatoes for processing into starch, it is essential to obtain high and stable starch yields, as determined by the yield of tubers and the content of starch in the tubers. The stability of these traits in potato varieties is especially important in variable environments affected by soil properties and climatic conditions. Pre-sprouting of the seed tubers before planting can accelerate plant development and promote acceptable starch yields in a shorter growing period. This study evaluated traits of seven potato varieties important for organic starch production, assessed trait stability in different environments and determined the effect of seed tuber pre-sprouting on plant development and stability parameters. Significant effects of genotype, growing environment, and their interactions on tuber yield, starch yield and starch content of the tubers were observed. No significant effects were found of seed tuber pre-sprouting on the performance of the tested traits. Four trait stability evaluation methods were applied to tuber yield, starch yield and starch content, including a modified Kang’s yield-stability approach, and these showed inconsistent results. The modified Kang’s stability rating could be further used for determination of the best performing varieties, with high values for the essential traits and relatively high stability for each individual trait.

One of the indicators of quality is the starch content of the tubers. In order to evaluate the starch content for each genotype, the Institute of Agricultural Resources and Economics had set up a field trial in organic crop production system with 10 potato varieties and 10 breeding clones. A field trial was carried out in 2018-2020. The aim of the study was to evaluate and select potato varieties and clones with high starch content in the organic farming system. The results proved impact of meteorological conditions on the starch content in the potato tubers. Starch content of varieties and clones varied from 12.68% to 20.63% on average in 3 years, significant impact of genotypes and years were observed (p<0.05). The highest starch content was found in 2019 for the variety ‘Kuras’ (21.32%) and for clones 19922.29 (21.0%) and 2008-6.5 (21.11%), also the following year these clones had a high starch content of (20.9%) and (21.17%), respectively. The high starch content in 2020 was also for the early varieties ‘Monta’ and ‘Rigonda’, ‘Prelma’ (21.17%). In 2018, many varieties and clones had a significantly lower starch content compared to 2019 and 2020 (p<0.05).

Potato proteins contains essential amino acids in considerably high concentration, therefore potatoes are considered to be one of the most valuable plant origin food for human consumption. Patatin forms one of the largest group of potato proteins with high potential to be used in food industry as a novel food. This study has been performed to approbate patatin determination method for evaluation of protein quality of potato genotypes, as well as evaluate patatin relative abundance (PRA) for breeding programmes to create in the future potato cultivars with higher value and potential to develop new products. The evaluation of patatin was performed in following steps– extraction proteins from potato, determination of patatin concentration and calculation of its relative abundance in proteins. Separation of patatin from potato tubers was made using extraction by SDS extraction buffer and determination of patatin in organically and conventionally (with differnt N suply) grown samples of 20 potato genotypes. The results of one-year study showed that patatin relative abundance of different cultivars varied from 1.65% to 50.2% and it was significantly different among genotypes. The nitrogen content of soil and maturity type of potato did not affect PRA significantly. Results provide impetus for further research.