Table Potato Cultivars Research Articles

Metabolomic and transcriptomic analyses identify external conditions and key genes underlying high levels of toxic glycoalkaloids in tubers of stress-sensitive potato cultivars.

High levels of toxic steroidal glycoalkaloids (SGAs) in potato tubers constitute a recognized food quality problem. Tuber SGA levels vary between potato cultivars and can increase after post-harvest stresses such as wounding and light exposure. A few cultivars, e.g., 'Magnum Bonum' and 'Lenape,' have been withdrawn from commercial sales due to excessive SGA levels during some cultivation years. However, these sudden SGA increases are diffucult to predict, and their causes are not understood. To identify external and genetic factors that underlie sudden SGA increases in certain potato cultivars, we have here in a 2-year study investigated 'Magnum Bonum' and five additional table potato cultivars for their SGA levels after wounding and light exposure. Results showed that 'Magnum Bonum' has an unusual strong SGA response to light exposure, but not to wounding, whereas 'Bintje' displayed an opposite regulation. Levels of calystegine alkaloids were not significantly altered by treatments, implicating independent metabolic regulation of SGA and calystegine levels also under conditions of high SGA accumulation. Metabolomic and transcriptomic analyses identified a small number of key genes whose expression correlated with SGA differences between cultivars. Overexpression of two key genes in transgenic low-SGA potato cultivars increased their leaf SGA levels significantly. The results show that a strong response to light can underlie the SGA peaks that occasionally occur in certain potato cultivars and indicate that a between-cultivar variation in the expression of single SGA key genes can account for cultivar SGA differerences. We propose that current attempts to mitigate the SGA hazard will benefit from an increased consideration of cultivar-dependent SGA responses to post-harvest conditions, particularly light exposure. The identified key SGA genes can now be used as a molecular tool in this work.

Influence of abiotic factors, inoculum source, and cultivar susceptibility on the potato tuber blemish diseases black dot (Colletotrichum coccodes) and silver scurf (Helminthosporium solani)

AbstractBlack dot and silver scurf are potato blemish diseases whose economic impact has increased in recent years. Because their symptomatology on tubers is visually similar, disease assessment does not usually differentiate between the two pathogens, which share the same ecological niche. The epidemiology of black dot has been extensively studied, especially in the UK, but the factors that influence silver scurf have been less investigated. In this study, the influence of cultivar, source of inoculum, and environmental conditions on both diseases was studied in field trials over a three‐year period (2016–2018) in Switzerland. Planting minitubers did not prevent either disease in daughter tubers, indicating the contribution of soil as an inoculum reservoir. An arbitrary threshold of Colletotrichum coccodes soil inoculum could be set to discriminate between low and high disease risk. For the first time, Helminthosporium solani DNA was detected in stolons, and infections appeared earlier in stolons than in tubers. H. solani stolon and tuber infections usually appeared later in the season than those of C. coccodes. Black dot severity correlated positively with precipitation, while silver scurf severity correlated positively with temperature. Table potato cultivars commonly grown in Switzerland exhibited significant differences in susceptibility to both diseases, and cultivars with low susceptibility to both silver scurf and black dot were identified. These results gave new insights into understanding the factors driving the epidemiology of potato blemish diseases and may contribute to building a risk assessment scheme to manage both diseases simultaneously.

Marketable Yield of Potato and Its Quantitative Parameters after Application of Herbicides and Biostimulants

Potato (Solanum tuberosum L.) is grown in over 160 countries. Weed competition and environmental stressors during the vegetative growth stage significantly impact crop yields. An experiment was conducted from 2012 to 2014 in Poland to assess the effect of herbicides linuron + clomazone (L+CH) and metribuzin (M) as well as herbicides mixed with biostimulants (linuron + clomazone and algae extract of Ecklonia maxima—auxins and gibberellins (L+CH+E) and metribuzin + sodium p-nitrophenolate, sodium o-nitrophenolate and sodium 5-nitroguaiacolate (M+S)) on weed infestation, marketable yield and yield components of the following three table potato cultivars: Bartek, Gawin and Honorata. In plots where potato had been treated with herbicides and herbicides mixed with biostimulants, a decline in the fresh matter of weeds was observed, ranging from 72.4% to 96.1%, which was followed by an increase in potato marketable yield (from 27.5% to 61%) and improved parameters of S. tuberosum yield components, compared with the control. Linear correlation coefficients indicated that the following characteristics: marketable yield, weight of tubers per plant and average weight per tuber were associated with weed infestation determined prior to potato harvest.

Assessment of Yield and Yield Components of Starch Potato Cultivars (Solanum tuberosum L.) Under Nitrogen Deficiency and Drought Stress Conditions

Water and nitrogen (N) management is a key factor in starch potato (Solanum tuberosum L.) production to ensure good yield and quality. Due to its shallow root system, potato is sensitive to drought and N uptake is limited to the upper soil layer resulting in leaching of nitrate. Efficient utilization of N and water can be optimized by adaptation of the cropping system and by selection of improved genotypes. A 2-year pot experiment with 14 modern starch and 3 table potato cultivars was conducted under controlled conditions in a rain-out shelter in order to investigate genotype-dependent responses to N deficiency and drought stress with regard to yield and yield components. Plants were grown at two N levels and a short-term drought-stress period during the sensitive tuber initiation stage was applied. Starch yield under control condition reached an average of 80.2 g plant−1, which was reduced under drought stress by 18% at sufficient N supply and by 23% at N deficiency. Sufficient N fertilization improved the water use efficiency under both continuous water supply and drought stress. N limitation increased the N use efficiency (NUE) at continuous watering, while NUE was not affected by drought stress at sufficient N supply but decreased under N deficiency. Genotype and drought as well as genotype and N level interactions were significant for all investigated traits, i.e. tuber yield (fresh and dry matter), starch and NKjeldahl contents, starch yield and water consumption.

The effect of herbicides and biostimulants on sugars content in potato tubers

The objective of the present work was to determine changes in total sugars, reducing sugars and sucrose content in potato tubers under conditions involving an application of biostimulants and herbicides. Research material included table potato tubers obtained in a three-year field experiment. The experiment was a split-plot design with three replicates. The factors were as follows: factor I – three table potato cultivars (Bartek, Gawin and Honorata), factor II – five methods of biostimulant and herbicide application (1. control – without biostimulants or herbicides; 2. Harrier 295 ZC (linuron + chlomazon); 3. Harrier 295 ZC (linuron + chlomazon) and growth regulator Kelpak<sup>®</sup>SL; 4. Sencor 70 WG (metribuzin); 5. Sencor 70 WG (metribuzin) and growth regulator Asahi<sup>®</sup>SL. Variance analysis demonstrated that total sugars, reducing sugars and sucrose content were affected by the biostimulants and herbicides applied as well as cultivars and weather conditions. Compared with control, a significant increase in total sugars followed an application of Sencor 70 WG as well as Sencor 70 WG and the growth regulator Asahi<sup>®</sup>SL whereas reducing sugars and sucrose content significantly increased after Sencor 70 WG and the growth regulator Asahi<sup>®</sup>SL were applied.

Effect of soil conditioner (UG<sub>max</sub>) application on the content of phenols and glycoalkaloids in potato tubers

The objective of the study was to determine the effect of the soil conditioner UG<sub>max</sub> application on phenol and glycoalkaloid content in the tubers of two table potato cultivars. The following factors were examined: factor I − cultivars: Satina and Tajfun; factor II − five application methods of the soil conditioner UG<sub>max</sub>: (1) control − no UG<sub>max</sub> application; (2) 1.0 L/ha UG<sub>max</sub> before planting; (3) 0.5 L/ha UG<sub>max</sub> before planting + 0.25 L/ha at potato height of 10–15 cm + 0.25 L/ha in flower bud phase; (4) 1.0 L/ha UG<sub>max</sub> before planting + 0.50 L/ha at potato height of 10–15 cm + in 0.50 L/ha in flower bud phase; (5) UG<sub>max</sub> applied after emergence when plants were 10–15 cm high at the rate of 0.5 L/ha, and at the stage of flower buds at the rate of 0.5 L/ha. The highest concentration of phenols and glycoalkaloids was recorded in plots where UG<sub>max</sub> was applied prior to potato planting at the rate of 1.0 L/ha, when plants were 10–15 cm high at the rate of 0.5 L/ha and at the stage of flower buds at the rate of 0.5 L/ha.

The effect of herbicides and biostimulants on polyphenol content of potato (Solanum tuberosum L.) tubers and leaves

Abstract The objective of the research was to determine the polyphenol content in the tubers and leaves of selected table potato cultivars cultivated using herbicides and biostimulants. A field experiment was conducted in Wojnow (52°12′59″N, 22°34′37″E), Poland (Multi-business ‘Solex’ Company) from 2012 to 2014. The experiment was a two-way random split-plot arrangement of plots with three replicates. The following factors were examined: three medium-early potato cultivars – Bartek, Gawin, Honorata, and five methods application of herbicides and biostimulants (Harrier 295 ZC, Sencor 70 WG, growth regulators Kelpak SL and Asahi, control where weeds were mechanically controlled). Polyphenol content was determined in fresh potato tuber mass by the spectrophotometric method using Folin-Ciocalteu reagent. The tuber content of polyphenols was affected by the cultivars, herbicides and biostimulants as well as weather conditions during the growing season. The herbicides and biostimulants increased the concentration of polyphenol compounds compared with the control tubers. Polyphenol content in potato leaves was significantly affected by cultivar traits only. Of the tested cultivars, Honorata and Gawin accumulated the most and the least polyphenols, respectively.

Effect of location on starch content and tuber texture characteristics in potato breeding lines and cultivars

ABSTRACTThe texture of boiled potato tubers is one of the most important quality traits. The variation of tuber texture is usually examined in relationship with dry matter or starch content. The objective of the work was to examine variation and stability of texture and starch content in tubers grown in various environments. Both traits were evaluated for the set of potato breeding lines and 10 table potato cultivars. The lines were developed in the program of parental lines carried out in Młochów Research Center, Poland. The environments were represented by three locations, which differed in cultivation system as well as climatic and soil conditions. The traits were influenced by the effects of genotype, location and their interactions. The effect of location on texture was not explained by the changes in starch content. The calculated stability parameters indicated that unstable expression of both traits was more pronounced and more frequent in breeding lines than in the cultivars. The short period of selection used in the development of the parental lines is not conducive to select potato genotypes with stable expression of quality traits. The starch content was at most moderately related with various characteristics of tuber texture.

Potassium phosphite combined with reduced doses of fungicides provides efficient protection against potato late blight in large-scale field trials

Potato late blight caused by the oomycete Phytophthora infestans is a devastating disease of potato worldwide. Most of the potato cultivars grown in conventional agriculture are susceptible, or at best moderately resistant, and require frequent applications of fungicides to avoid heavy yield losses.In field trials spanning four years, we have investigated the effect of potassium phosphite, an inorganic salt on potato late blight. Potassium phosphite is known to induce defence responses in potato and to also have direct toxic effects on oomycetes, which in turn counteract late blight and tuber blight development. However, the use of this salt is not yet implemented and approved in European potato cultivation. We compared the effect of phosphite alone with fungicides currently used in Swedish potato cultivation. We also investigated the combined use of potassium phosphite and reduced doses of fungicides. Table potato cultivars and starch potato cultivars with different levels of resistance were used.We found that potassium phosphite in combination with reduced doses of fungicides results in the same level of protection as treatments with the recommended full dose of fungicides. These combined treatments reduce the need of traditional fungicides and may also decrease the selection pressure for fungicide resistance development in the pathogen. In relatively resistant starch potato cultivars using phosphite alone gave sufficient protection against late blight. Furthermore, in starch potato a combination of phosphite and fungicides at two-week intervals provided similar protection to weekly applications of fungicide at the recommended dose. Foliar treatment with phosphite also gave protection against tuber blight at similar levels to that of the best-performing fungicide. Our data suggests that potassium phosphite could be used in potato cultivation in temperate regions such as in Sweden, at least in combinations with reduced rates of fungicides. The implementation of the use of phosphite in practical potato crop protection as part of an IPM strategy is discussed. Doses, intervals and combinations could be adjusted to the level of cultivar resistance.

Effect of biostimulators on yield and selected chemical properties of potato tubers

Growth regulators stimulate life processes in plants, improving their stress resistance and health, which translates into higher and better quality yield. Growth regulators can improve biochemical parameters of tubers and enhance the potato’s resistance to adverse environmental conditions or pathogens. The purpose of this research was to examine the effect of biostimulators on yield and selected chemical properties of potato tubers. Four table potato cultivars were grown in a field experiment: very early Volumia and medium early Irga, Satina and Sylvana. Starting from stage 39 on the BBCH scale (crop cover complete), potato plants were treated thrice, in 10to 14-day intervals, with the growth regulators Asahi SL, Bio-Algeen S90 and Kelpak. The reference treatment was composed of potatoes untreated with the bioregulators. The growth regulators, especially Bio-Algeen S90 (6.3 – 16.3%) and Kelpak SL (14.2-24.7%) raised the tuber yield, but the effect was statistically verifiable only in the second year, with less precipitation and lower temperature of the vegetation period. The quality of potato tubers was more strongly dependent on the cultivar-specific traits than on the applied biostimulators. In the second year, too, potato tubers contained on average 34% more N-total than in the first year. During storage, the content of N-total in tubers increased by 35-50%. After a five-month storage period, potato tubers contained more NO3 abut less N-NH4.

生食用ジャガイモ品種の低温貯蔵による糖含量の増加特性

生食用ジャガイモ品種の低温貯蔵による糖増加特性を解析した．品種によって糖の増加程度が異なること，特に「インカのめざめ」「インカのひとみ」は長期低温貯蔵で糖が顕著に増加することが明らかとなった．増加した糖組成の解析から「インカのめざめ」は「ショ糖増加型」，「キタアカリ」は「還元糖増加型」，「ノーザンルビー」は両タイプの中間的な特性を持つ品種であることがわかった．「インカのめざめ」においては，二地点の圃場で収穫された塊茎でも同一カ所の低温貯蔵で1ヶ月以降同程度の糖増加が見込めること，低温貯蔵出庫後，室温におくと1週間程度で増加した糖の40%弱が，1ヶ月後までには50∼70%強が消失すること，1週間後までに室温から低温に戻せばその後3週間程度で出庫時の80%程度まで糖量を回復できることが明らかとなった．

Glycoalkaloid and Calystegine Levels in Table Potato Cultivars Subjected to Wounding, Light, and Heat Treatments

Potato tubers naturally contain a number of defense substances, some of which are of major concern for food safety. Among these substances are the glycoalkaloids and calystegines. We have here analyzed levels of glycoalkaloids (α-chaconine and α-solanine) and calystegines (A₃, B₂, and B₄) in potato tubers subjected to mechanical wounding, light exposure, or elevated temperature: stress treatments that are known or anticipated to induce glycoalkaloid levels. Basal glycoalkaloid levels in tubers varied between potato cultivars. Wounding and light exposure, but not heat, increased tuber glycoalkaloid levels, and the relative response differed among the cultivars. Also, calystegine levels varied between cultivars, with calystegine B4 showing the most marked variation. However, the total calystegine level was not affected by wounding or light exposure. The results demonstrate a strong variation among potato cultivars with regard to postharvest glycoalkaloid increases, and they suggest that the biosynthesis of glycoalkaloids and calystegines occurs independently of each other.

Cultivar Variability of Patatin Biochemical Characteristics: Table versus Processing Potatoes (Solanum tuberosum L.)

Biochemical characteristics of patatin proteins purified by ion-exchange and affinity chromatography from tubers of 20 potato cultivars were studied to evaluate their genotype differences with respect to utility groups, table potato cultivars (TPCs) and processing potato cultivars (PPCs). Both groups of cultivars showed similar values of protein content in dry matter (3.98-7.39%) and of patatin relative abundance (5.40-35.40%). Three mass levels (∼40.6, 41.8, and 42.9 kDa) of purified patatins were found by MALDI-TOF MS within all cultivars. Differences among mass levels corresponding with the mass of sugar antenna (∼1.2 kDa) confirmed the previous concept of different glycosylation extentsin patatin proteins. It was showed that the individual types of patatin varying in their masses occur in the patatin family in a ratio specific for each of the cultivars, with the lowest mass type being the major one. Electrophoretic analyses demonstrated wide cultivar variability in number of patatin forms. Especially 2D-PAGE showed 17-23 detected protein spots independently on the utility group. Specific lipid acyl hydrolase (LAH) activity of purified patatins from the individual tested cultivars varied between 0.92 and 5.46 μmol/(min mg). Patatin samples within most of the TPCs exhibited higher values of specific LAH activity than samples of PPCs. It may be supposed that individual patatin forms do not have similar physiological roles.

Patatin, the major protein of potato (Solanum tuberosum L.) tubers, and its occurrence as genotype effect: processing versus table potatoes

Patatin relative abundance in SDS-extractable protein and patatin content in dry matter were evaluated in tubers of forty processing and table potato cultivars usually cultivated in the Czech Republic, Germany, and the Netherlands. The patatin characteristics were evaluated over three experimental years. Patatin relative abundance in the processing cultivars achieved on average a significantly higher value (<I>P</I> < 0.001; Tukey HSD test) than patatin relative abundance in the table cultivars, resulting in average values of 25.80% and 21.59%, respectively. A high patatin relative abundance (over 30% in extractable protein) was determined only in the case of two cultivars: Vaneda (average 31.29%) and Tomensa (average 31.24%). Patatin content in tuber dry matter was significantly higher in the processing potato cultivars in all three experimental years (<I>P</I> < 0.001), attaining a mean of 1.28% with the processing cultivars and 1.03% with the table cultivars. The direct effect of the cultivar on patatin relative abundance in SDS-extractable protein was higher (33.1% for processing potato cultivars and 48.1% for table potato cultivars) than the effect of the growing year (15.6% for processing potato cultivar and 22.8% for table potato cultivars).