Tuber Formation Research Articles

APPLICATION OF PECTIC POLYSACCHARIDES AS STIMULANTS FOR GROWTH AND DEVELOPMENT OF SOLANUM TUBEROSUM L.

Crop yields can be significantly increased by using pectic polysaccharides – natural ecologically safe and effective plant growth stimulants. In this paper, high growth-stimulating activity of pectins with respect to potatoes is shown. The research was conducted in 2012–2015 in the Komi Republic (Syktyvkar) on sod-podzolic soils with an average humus content of 2.8–3.4%. The objects of the study in the field experiments were zoned potato varieties: early-ripening Gloria variety and the middle-aged variety Nevsky. The following pectic polysaccharides served as stimulants of potato growth and development: heracleuman – pectin of Heracleum sosnowskyi Manden., lemnan – pectin duckweed Lemna minor L. and silenan – pectin of callus tissue of campion Silene vulgaris (M.) G. Processing of potatoes with aqueous solutions of pectic polysaccharides included pre-planting soaking of potato tubers in water and spraying potato plants in the phases of 3–5 leaves and tuber formation. For processing potatoes, working solutions were used, which were prepared from 100 times diluted 0.002% aqueous solutions of pectins. The consumption of the working solutions of pectins were 10 liters on 1 ton of tubers and 300 l/ha of planting potatoes. Tubers and potato plants treated with water instead of pectins were used as control samples. It is established that all tested pectins possess growth-stimulating activity and processing of potatoes with aqueous solutions of pectic polysaccharides increases the early and overall yield of this crop, as well as the content of dry matter, starch and vitamin C in potato tubers.

Genome-wide transcriptome analysis reveals small RNA profiles involved in early stages of stolon-to-tuber transitions in potato under photoperiodic conditions

BackgroundSmall RNAs (sRNAs), especially miRNAs, act as crucial regulators of plant growth and development. Two other sRNA groups, trans-acting short-interfering RNAs (tasiRNAs) or phased siRNAs (phasiRNAs), are also emerging as potential regulators of plant development. Stolon-to-tuber transition in potato is an important developmental phase governed by many environmental, biochemical and hormonal cues. Among different environmental factors, photoperiod has a major influence on tuberization. Several mobile signals, mRNAs, proteins and transcription factors have been widely studied for their role in tuber formation in potato, however, no information is yet available that describes the molecular signals governing the early stages of stolon transitions or cell-fate changes at the stolon tip before it matures to potato. Stolon could be an interesting model for studying below ground organ development and we hypothesize that small RNAs might be involved in regulation of stolon-to-tuber transition process in potato. Also, there is no literature that describes the phased siRNAs in potato development.ResultsWe performed sRNA profiling of early stolon stages (4, 7 and 10 d) under long-day (LD; 16 h light, 8 h dark) and short-day (SD; 8 h light, 16 h dark) photoperiodic conditions. Altogether, 7 (out of 324) conserved and 12 (out of 311) novel miRNAs showed differential expression in early stolon stages under SD vs LD photoperiodic conditions. Key target genes (StGRAS, StTCP2/4 and StPTB6) exhibited differential expression in early stolon stages under SD vs LD photoperiodic conditions, indicative of their potential role in tuberization. Out of 830 TAS-like loci identified, 24 were cleaved by miRNAs to generate 190 phased siRNAs. Some of them targeted crucial tuberization genes such as StPTB1, POTH1 and StCDPKs. Two conserved TAS loci, referred as StTAS3 and StTAS5, which share close conservation with members of the Solanaceae family, were identified in our analysis. One TAS-like locus (StTm2) was validated for phased siRNA generation and one of its siRNA was predicted to cleave an important tuber marker gene StGA2ox1.ConclusionOur study suggests that sRNAs and their selective target genes could be associated with the regulation of early stages of stolon-to-tuber transitions in a photoperiod-dependent manner in potato.

The effects of different concentration of sucrose and various auxin on in vitro shoot and microtuber formation of red potato (Solanum tuberosum, L. var Desiree)

The experiment was aims to study the effect of different sucrose concentrations (30, 90, 120 and 150 g.L−1) and various types of auxin (IAA, IBA, NAA) on in vitro shoot and microtuber formation of Red Potato (Solanum tuberosum, L. var Desiree). Young stem cutting from planlet cultured on half strength MS medium. All types of auxin use the concentration of 0.25 mg.L−1. The research conducted a completely randomized design (CRD) factorial. The data obtained were analyzed by analysis of variance (ANOVA) and DMRT test at 0.05. Parameters observed included growth of microtuber and shoot growth, such as number of shoots and shoot length. The observations result for 3 months, show that the higher the concentration of sucrose, can stimulate tuber formation but suppress shoot growth. Early tuber initiation (36,7 DAP) and optimum number of tuber was observed in 150 g.L−1 sucrose, whereas at 30g.L−1 had no effect to tuber induction. In addition, high number of microtuber was observed in NAA compare to other auxin. Observational data on shoot growth showed that the higher concentration of sucrose will inhibit bud formation. The 90 g.L−1 sucrose concentration showed the best number of shoots, which averaged 1.5 shoots/plantlet. But at a concentration of 30g/L sucrose, explants are only able to form callus. In the bud length parameter, IAA gave the best response that is an average of 3cm/shoot.

Mapping and QTL Analysis of Early-Maturity Traits in Tetraploid Potato (Solanum tuberosum L.).

Early maturity is one of the most important agronomical traits in potato breeding. To identify the DNA segment that codes for early maturity, a tetraploid potato segregation population of “Zhongshu 19” × “Zhongshu 3” was genetically analyzed, using a combination of high throughput simplified genome sequencing (2b-RAD) and bulked segregant analysis (BSA). The DNA segment related to the early-maturity trait was identified at the 3.7~4.2 Mb locus on the short arm of chromosome 5. Eight molecular markers were developed, of which five were closely linked to the early-maturity trait loci. Additionally, 42 simple sequence repeats (SSR) markers were constructed based on the reference sequence of Solanum tuberosum group Phureja DM1-3 516 R44 (DM). Using the TetraploidMap software, the linkage map of chromosome 5 was constructed with 50 markers. The total map length was 172 centiMorgan (cM), with an average genetic distance of 3.44 cM. Correlating molecular and phenotypic data of the segregating population, the mapped Quantitative Trait Loci (QTL) on the short arm of chromosome 5 contributed to 33.55% of the early-maturity phenotype. The early-maturity QTL was located at 84 cM, flanked by the SSR5-85-1 and SCAR5-8 markers. The QTL was fine-mapped to 471 kb. Using DNA sequence annotation, 34 genes were identified in this region, 12 of them with unknown function. Among the other 22 annotated genes, E3 ubiquitin ligase gene PUB14 could be related to maturity and regulation of tuber formation. The constructed QTL map is a useful basic tool for the cloning of early-maturity related genes in tetraploid potatoes.

Planting Techniques and Irrigation Influenced Crop Growth, Light Interception and Yield–Evapotranspiration Relationship of Potato

Attempts were made to study effects of planting techniques on crop dry matter (DM), intercepted photosynthetically active radiation (fIPAR), tuber yield (y), evapotranspiration (ET), water-use efficiency and y–ET relationship of potato under varying irrigation regimes. Field experiments were conducted for three seasons with four irrigation regimes: 2, 3, 4 and 5 numbers of irrigation per season (I1, I2, I3 and I4, respectively), and three planting methods: S1-normal single row planting with 50-cm row-to-row and 15-cm plant-to-plant spacing with 50-cm furrow spacing; S2-paired-row planting at 25-cm spacing, 75-cm furrow spacing; and S3-paired-row planting at 50-cm spacing with 100-cm furrow spacing. Though the highest tuber yield was recorded in I4, it was marginally higher than that in I3; whereas the highest WUE was obtained with I3. Optimum irrigation in I3 and I4 maintained higher crop DM, greater fIPAR, ET and better tuber formation than in I1 and I2. No significant yield reduction occurred due to paired-row method (S2); however, irrigation volume reduced by 21%; crop WUE increased by 8.2% and irrigation WUE increased by 21% in S2 compared with S1. The y–ET functions were found quadratic with downward concave; and elasticity of water production functions (Ewp) were used to reveal the dynamic relationship of y, ET and WUE. Findings suggest that the ET of 348 mm would be required to achieve maximum WUE of 44.11 kg ha−1 mm−1 with paired-row furrow irrigated system; and this would result in tuber yield of 15.42 t ha−1. Crop response factor (Ky) values indicated that tuber yield reduction would be directly proportional to reduced irrigation. Therefore, it is concluded that potato could be grown with paired-row method of planting at 75 × 20 cm spacing, and the ET demand of 348 mm should be met to achieve maximum tuber yield and increased WUE. The study could be an important reference for water-saving of potato production in tropical sub-humid conditions.

Genetically engineered human cortical spheroid models of tuberous sclerosis.

Tuberous Sclerosis Complex (TSC) is a multi-system developmental disorder caused by mutations in the TSC1 or TSC2 genes, whose protein products are negative regulators of mTOR complex 1 signaling. Hallmark pathologies of TSC are cortical tubers; regions of dysmorphic, disorganized neurons and glia in the cortex that are linked to epileptogenesis. To determine the developmental origin of tuber cells, we established human cellular models of TSC by CRISPR/Cas9-mediated gene editing of TSC1 or TSC2 in human pluripotent stem cells (hPSCs). Using heterozygous TSC2 hPSCs with a conditional mutation in the functional allele, we show that mosaic biallelic inactivation during neural progenitor expansion is necessary for the formation of dysplastic cells and increased glia production in three-dimensional cortical spheroids. Our findings provide support for the second-hit model of cortical tuber formation and suggest that variable developmental timing of somatic mutations could contribute to the heterogeneity in the neurological presentation of TSC.

ВЛИЯНИЕ ГУСТОТЫ ПОСАДКИ КЛУБНЕЙ КАРТОФЕЛЯ НА УРОЖАЙНОСТЬ, СТРУКТУРУ УРОЖАЯ, КАЧЕСТВО ПРОДУКЦИИ И ТОВАРНОСТЬ КЛУБНЕЙ

The article deals with the influence of planting depth of potato tubers on productivity, structure, quality of products and the marketability of potato crop in the conditions of the Chuvash Republic. The depth of seeding of tubers has a direct impact on all processes of growth and development. The more favorable the complex of conditions in the zone of placement of planted tubers, the faster they germinate and give early and amicable shoots, the more successful the further development of the potato plant and the formation of the crop. Determining the dependence of the potato tuber planting depth on the productivity, structure, quality of the products and the marketability of potato plants hinders many causes that are directly related to the growth and development of potato plants, as the productivity of potato plants is significantly increased by optimizing the priority conditions that are necessary in potato cultivation, when there is an increase in all indicators of photosynthetic activity of potato plants. The density of plants should be such that plants could form a powerful leaf surface, a root system and make the best use of solar energy and soil nutrients [11 12]. In numerous studies by our and foreign authors on the definition of optimal areas of potato nutrition, the following general provisions are present: late varieties, that develop a powerful top, are placed less often, early - thicker; the less moisture in the soil, the less should be the density of planting [6]. In this study, in order to determine potato productivity, we first of all determined crop yields, structure, product quality and marketability of tubers. Norms of planting can be determined depending on the density of the stalk. The high density of plant standings promotes acceleration of passage of development phases by plants, early tuber formation and ripening of a potato [3,4,5,7,8,9]. Thus, in the experiments, carried out by V.T. Spiridonov (1972) in the Chuvash Agricultural Institute in the variant where the planting was carried out according to the scheme of 70x30 cm, the entry of plants into the mass flowering phase was noted 2-3 days earlier than when planting according to the scheme of 70x35 cm. Reduction of the distance between tubers to 25 cm accelerated the development of plants 5 days.

Tuber formation as influenced by the C : N ratio in potato plants

AbstractIncreasing the tuber number per plant and promoting tuber formation are important goals for potato production. Thus, it is of significance to understand how environmental factors affect tuber formation, which relates to the development of agronomical practices. The objective of this research was to test whether changing the CO2 or N supply level could alter the C : N ratio in potatoes, and whether a change of the C : N ratio in potatoes closely correlates with tuber formation in potato plants. Potato plantlets were grown in greenhouse with varied CO2 or N levels. The C and N concentrations of plants were measured, and the tuber number and tuber weight were recorded after different growth times. The results show that the C : N ratios in the potato plants increased with increasing CO2 concentration and that potato plants treated with higher CO2 concentrations form tubers earlier. A decrease in the N supply also resulted in a higher C : N ratio and earlier tuber formation. Therefore the hypothesis proposed previously is supported by the present work. In addition, the results that C concentration in plants remained stable under different CO2 or N levels imply that the variation of C : N ratio in the potato plants is mainly due to a change of N concentrations which decreased as the environmental CO2 concentration increased, while increased as the N supply level increased.

Cytokinin perception in potato: new features of canonical players.

Potato is the most economically important non-cereal food crop. Tuber formation in potato is regulated by phytohormones, cytokinins (CKs) in particular. The present work studied CK signal perception in potato. The sequenced potato genome of doubled monoploid Phureja was used for bioinformatic analysis and as a tool for identification of putative CK receptors from autotetraploid potato cv. Désirée. All basic elements of multistep phosphorelay required for CK signal transduction were identified in the Phureja genome, including three genes orthologous to three CK receptor genes (AHK 2-4) of Arabidopsis. As distinct from Phureja, autotetraploid potato contains at least two allelic isoforms of each receptor type. Putative receptor genes from Désirée plants were cloned, sequenced and expressed, and the main characteristics of encoded proteins were determined, in particular their consensus motifs, modelled structure, ligand-binding properties, and ability to transmit CK signals. In all studied aspects the predicted sensor histidine kinases met the requirements for genuine CK receptors. Expression of potato CK receptors was found to be organ-specific and sensitive to growth conditions, particularly to sucrose content. Our results provide a solid basis for further in-depth study of CK signaling system and biotechnological improvement of potato.

Вплив ярусів живців пробіркових рослин і живильного середовища на індукцію бульбоутворення картоплі in vitro сортів різних груп стиглості

Вплив ярусів живців пробіркових рослин і живильного середовища на індукцію бульбоутворення картоплі in vitro сортів різних груп стиглості

Drought response in field grown potatoes and the interactions between canopy growth and yield

Potato is an important food crop with high yields. However when exposed to drought it suffers major yield losses. Considering its global importance and the increasing incidence of drought due to climate change, research toward drought tolerance in potato remains imperative. We have studied a set of 103 commercial cultivars representing the genetic diversity in the European potato market. The cultivars were grown in different field locations in three subsequent years (2013–2015). Our aim was to understand how different field drought regimes affect canopy growth in potato, and how these effects translate to tuber yield. The field environmental conditions were monitored, and pictures of canopy ground cover during the growing season were taken. Canopy growth parameters were extracted by an iterative method using the beta sigmoid growth function to model canopy growth. At harvest, tuber yield was scored and tuber size was graded. The GGE (Genotype and Genotype-by-Environment) bi-plot and Finlay Wilkinson’s Regression were used to investigate Genotype x Environment interactions. We observed that the timing of the drought occurrence differentially affected canopy growth and tuber yield. Under drought stress, fast attainment of exponential growth and maximum canopy cover had negative effects on tuber formation and tuber bulking. Growth rate, maximum canopy cover, and area under the canopy curve (photosynthetic capacity over the growth season) were more important for tuber bulking than they were for tuber formation under drought stress. Cultivars with high yield were identified as potential material for improvement to drought tolerance. These findings will contribute to the breeding for drought-tolerant potato amidst the threats of climate change.

Keragaman Morfologi Umbi Ubijalar untuk Konsumsi Bayi dan Anak-anak Suku Dani di Distrik Kurulu Kabupaten Jayawijaya

<em>Sweet potato serves as main staple food for people in Jayawijaya. Many cultivars of sweet potatoes have been cultivated by Dani tribe in Kurulu as source food for their infant, children and adult as well as for animal feed especially pigs.The research was conducted at Woisila and Woisilo, Dany tribe Kurulu District, Jayawijaya. The aim of the research was to study the diversity of sweet potatoes tuber that cultivated by Dani tribe at Kurulu Districk as source of food for their infant and children. �Ten cultivars of sweet potatoes tuber consumted by infant and children of Dany tribe was morphologically characterized. The result showed that nine of ten cultivars produced tubers. �The research also categorizes different character of tubers. These characters are: four different tuber shapes, four groups of tuber cortex thickness, three groups of predominant tuber skin colour, five groups of secundary tuber skin colour, five groups of predominant tuber flesh colour of tuber, three groups of secundary tuber flesh colour, four types of secondary tuber flesh colour distribution, four types of tuber formation, two groups of tuber stalk, five groups of tuber �number per plant, �and �three cultivars with tuber craking.</em>

Inhibition of plastid PPase and NTT leads to major changes in starch and tuber formation in potato.

The importance of a plastidial soluble inorganic pyrophosphatase (psPPase) and an ATP/ADP translocator (NTT) for starch composition and tuber formation in potato (Solanum tuberosum) was evaluated by individual and simultaneous down-regulation of the corresponding endogenous genes. Starch and amylose content of the transgenic lines were considerably lower, and granule size substantially smaller, with down-regulation of StpsPPase generating the most pronounced effects. Single-gene down-regulation of either StpsPPase or StNTT resulted in increased tuber numbers per plant and higher fresh weight yield. In contrast, when both genes were inhibited simultaneously, some lines developed only a few, small and distorted tubers. Analysis of metabolites revealed altered amounts of sugar intermediates, and a substantial increase in ADP-glucose content of the StpsPPase lines. Increased amounts of intermediates of vitamin C biosynthesis were also observed. This study suggests that hydrolysis of pyrophosphate (PPi) by action of a psPPase is vital for functional starch accumulation in potato tubers and that no additional mechanism for consuming, hydrolysing, or exporting PPi exists in the studied tissue. Additionally, it demonstrates that functional PPi hydrolysis in combination with efficient ATP import is essential for tuber formation and development.

Restoration of fertility of the tech soils of Irshan mining and concentrating combine

This paper deals with agroecological state of disturbed soils on the territory of the Irish Mining and Processing Plant, where titanium raw material is extracted. The analysis of the suitability of the tech soils of the 10–30 year period of disclosure with the application of the fertile soil layer has been carried out and the possibility of using the lupine of the narrow-leaf as a sideral and nitrogen-fixing culture for biological regeneration and restoration of their fertility has been studied. The high symbiotic efficiency of the formation of tubers, the accumulation of nitrogen and the use of green mass and root lobular margarine lobules for reproduction of fertility have been proved. It has been proved that the overgrowth phytomass and roots of lupine superficial roots accumulation contribute to the accumulation of nitrogen in the amount of 42–46 kg/ha, and the symbiotic fixed nitrogen of air — 134–156 kg/ha.

English

English

Effect of vernalization on tuberization and flowering in the Tibetan turnip is associated with changes in the expression of FLC homologues

The turnip (Brassica rapa var. rapa) is a biennial crop that is planted in late summer/early fall and forms fleshy tubers for food in temperate regions. The harvested tubers then overwinter and are planted again the next spring for flowering and seeds. FLOWERING LOCUS C (FLC) is a MADS-box transcription factor that acts as a major repressor of floral transition by suppressing the flowering promoters FT and SOC1. Here we show that vernalization effectively represses tuber formation and promotes flowering in Tibetan turnip. We functionally characterized four FLC homologues (BrrFLC1, FLC2, FLC3, and FLC5), and found that BrrFLC2 and BrrFLC1 play a major role in repressing flowering in turnip and in transgenic Arabidopsis. In contrast, tuber formation was correlated with BrrFLC1 expression in the hypocotyl and was repressed under cold treatment following the quantitative downregulation of BrrFLC1. Grafting experiments of non-vernalized and vernalized turnips revealed that vernalization independently suppressed tuberization in the tuber or hypocotyl of the rootstock or scion, which occurred in parallel with the reduction in BrrFLC1 activity. Together, our results demonstrate that the Tibetan turnip is highly responsive to cold exposure, which is associated with the expression levels of BrrFLC genes.

Morphological and Physiological Response of Potato for Radiation and Salt Stress in vitro

The experiments were undertaken to study the response and behavior of two mutant clones of Potato genotype for salt stress by exposing it to different salt levels of sodium chloride (with electrical conductivity of 8, 10, 12 dS m-1) and compare with those in the control treatment 6 dS m-1. The morphological response was determined by measuring the morphological characteristics of vegetation, root growth, tuber formation. While the physiological response was determined by estimating some ions in the vegetative and root growth. The results showed a significant decrease in the morphological characteristics of the vegetative growth (number of shoots, plant height and dry weight) and tuber formation by increasing salt levels, while the characteristics of the root growth (number of roots, lengths and dry weight) were not affected. There is no significant difference in the behavior of the two clones under saline levels, except for the superiority of vegetative clone (C2) at comparison treatment in the number of shoots (2.00 shoot / plant), and vegetative clone (C1) at comparison treatment and 12 ds m-1 in the shoot length and the percentage of tuber formation (13.40 cm and 100% Respectively). The results also recorded that the root growth of vegetative clone (C2) was a significant accumulation of Na+ and Ca++ at 12 dS m-1 which reached 8.33 and 23.38 mg-1 gm dry weight, respectively, while the accumulation of K+ in vegetative clone (C1) was increased by the root growth in the control treatment which reached 45.03 mg -1 gm dry weight.

Pengaruh Modifikasi KH2PO4, NH4NO3 dan Sukrosa terhadap Pertumbuhan Tunas serta Pembentukan Umbi Mikro Taka (Tacca leontopetaloides) secara In vitro

ABSTRACT Polynesian arrowroot (Tacca leontopetaloides (L.) Kuntze), which is one of the bulbous herbaceous plants, have high nutritional value. Modification of macro nutrients by reducing nitrogen content and increasing phosphorus on the medium gave affects on shoot growth and initiated micro tuber formation on in vitro cultures. The aim of this research was to determine the effect of modified macro nutrients in combination with the increase in sucrose concentrations on shoot growth and micro tuber formation of T. leontopetaloides. The experimental design was factorial completely randomized design.The factors tested were modifications of MS macro nutrients that were. M1 (170 mg/l KH2PO4 and 1650 mg/l NH4NO3; normal, control treatment); M2 (340 mg/l KH2PO4 and 825 mg/l NH4NO3); and M3 (680 mg/l KH2PO4 and 412.5 mg/l NH4NO3 in combination with 30 (S1) (control treatment), 40 (S2), 50 (S3) and 60 g/l of sucrose (S4). The variables tested were shoot height, number of leaves, number of roots and number of micro tuber which were observed weekly at 0-8 weeks after culturing. The results showed that the modification of macro nutrient in combination with sucrose concentration had significant effect on shoot height, number of leaves and number of roots but not significant on the number of tubers. The highest shoots were found in M1S3 treatment, the highest number of leaves was in M1S1 and M1S3 treatment and the highest number of roots was in M1S4 treatment. The number of tubers not significantly different between the treatments tested. Keywords: in vitro, KH2PO4, microtuber, NH4NO3, sucrose, Tacca leontopetaloides

Оценка сортов картофеля по урожайности и биохимическим показателям в условиях Кировской области

Potato is one of the most important foodstulfs for wide layers of population in the Russian Federation. Materials of 2014-2017 competitive testing investigation of potato varieties by productivity and basic biochemical parameters of tubers (the content of dry matter, starch, protein, vitamin C, and reducing sugars) in Kirov region are presented in the article. The objects of study are 9 varieties of two maturity groups: early and middle-early, mid ripening and middle-late. Perspective potato varieties of different terms of maturity combining high productivity and tuber quality have been selected. Within the first group the variety samples bred in Falenki breeding station are chosen: an early sample 179-10, which has an average productivity of 34.8 t/ha, addition to the standard Udacha (All-Russia Research Institute of Potato Farming) is 3.1 t/ha, addition to the standard Nevsky (North West Research Institute of Agriculture)- 8.8 t/ha, tubers are round, of white color, noted for uniformity in nest and good taste; a middle-early sample 90-09 with productivity of 30.6 t/ha and starch content 15.4%. In the second group - a middle sample 109-09 with productivity of 27.9 t/ha, maximum starch content 17%. Within recognized varieties, Chaika (Falenki breeding station) had a higher concentration of starch; a higher content of vitamin С was recorded in Viza (Falenki breeding station) and Nevsky; Viza and Gloriya (Falenki breeding station) have good taste. Varieties Virazh (Falenki breeding station), Nevsky, and sample 34-07 are good for chips production because of high content of dry matter and low content of reducing sugars. It has been established that higher humidity during the period of active tuber formation had a negative effect on the content of dry matter and protein in potato tubers (r = -0.88 and -0.89 respectively).

Wpływ Tytanitu na zawartość suchej masy i makropierwiastków w bulwach ziemniaka

This paper analyses the effect of the dose (0.2 L*ha-1 or 0.4 L*ha-1) and date (a single application at the leaf development stage – BBCH 14-16 or at the tuber formation stage – BBCH 41-43, and a double application at the BBCH 14-16 and BBCH 41-43 stages) of the application of Tytanit® (8.5 g Ti per liter in the form of Ti-ascorbate) on the dry matter and macroelement contents in tuber of very early potato cultivars (‘Lord’ and ‘Milek’). Potatoes were harvested 75 days after planting (the end of June). Tytanit® did not affect the content of dry matter and nitrogen, phosphorus, potassium, calcium, magnesium or sulphur in potato tubers. Following Tytanit® application, there was only an increase in sodium content. The sodium content in the immature potato tubers was higher after the application of 0.2 L*ha-1 of the Tytanit®. Regardless of the Tytanit® dose, the sodium content in tubers was the lowest when the growth stimulant was applied only once in the leaf development stage (BBCH 14-16), particularly under the more favorable thermal and moisture conditions for early crop potato culture. Following Tytanit® application, the weight ratios of Ca:P, K:Ca and K:Mg in potato tuber were similar, and the weight ratios of N:S, Na:Ca and Na:Mg were broader compared to the cultivation without the growth stimulant, although the ratio of the sum of univalent cations to the sum of bivalent cations (K+Na):(Ca+Mg) was at the same level, both in the cultivation with and without Tytanit®.