Composition Of Tubers Research Articles

The role of plant-derived melanin in enhancing <i>in vitro</i> growth and nutrient accumulation in potato varieties

Background: Melanins are versatile biopolymers found in a wide range of living organisms, contributing to the diverse colors observed in nature. Beyond their pigmentation role, melanins exhibit a variety of biological activities, including antioxidant, antitoxic, antitumor, photoprotective, antimicrobial, and radioprotective properties. These attributes make melanins valuable in fields such as medicine, pharmaceuticals, and agriculture. In this study, we investigated grape marc, a byproduct of wine production, as a novel source of water-soluble melanin extracted using sodium hydroxide. This approach not only repurposes agricultural waste but also explored melanin's role in optimizing in vitro plant cultivation. We evaluated the impact of melanin on the biochemical properties of potato plants, focusing on improvements in growth, rhizogenesis, and the nutritional composition of tubers. Objective: The aim of this study was to evaluate the effects of plant-derived melanin on the in vitro growth characteristics and biochemical composition of two potato varieties. Methods: This study took place in the tissue culture laboratory at the Scientific Center of Agrobiotechnology from 2021 to 2024. Apical meristems from the Nevsky and Impala potato varieties were used for in vitro regeneration. The research focused on the in vitro growth and adaptation of these plants under different melanin concentrations. Key growth parameters, chlorophyll content, and biochemical composition were analyzed to assess the impact of melanin on potato development. Results: The study found that melanin at a concentration of 0.028% significantly enhanced the in vitro growth and rhizogenesis of potato microstems, with optimal results in root number (12.30 per shoot) and shoot length (16.91 cm). Plants also showed earlier and more vigorous root formation, resembling an auxin-like effect. Higher melanin concentrations reduced these benefits. Additionally, plants treated with 0.028% melanin had a high acclimatization success rate (96%) and improved biochemical composition in tubers, with increases in dry matter, sugars, starch, and ascorbic acid, particularly in the Nevsky variety. Conclusion: Melanin significantly stimulated the in vitro growth and development of potato plants. Increasing melanin levels to an optimal threshold accelerated rhizogenesis and promoted vigorous root and shoot growth, evidenced by increased length and thickness. Acting similarly to auxin, melanin not only encouraged root formation but also enhanced shoot development, leading to improved plant adaptation. Additionally, melanin influenced the biochemical composition of potato tubers, including their nutritional content. These findings highlight the crucial role of melanin concentration in optimizing the growth and biochemical properties of potato varieties. Keywords: in vitro propagation, potato, melanin, plant adaptation, biochemical compound, micropropagation

The Impact of Nitrogen Levels on the Growth, Development, and Yield of Orange-fleshed Sweet Potatoes (Ipomoea batatas L.)

Nitrogen (N) is one of the most important fertilizers in agriculture because it promotes the growth of plants and the uptake of other plant nutrients. This nutrient plays a significant role in determining the yield and nutrient composition of sweet potato root tubers. Therefore, this study aimed to determine the optimum application rate of N in sweet potatoes to maximize yields and increase growth efficiency. Four levels of N (50, 100, 150, and 200 kg/ha) were applied as treatments. A randomized complete block design was used, and each treatment was replicated five times. Vine length, leaf length, stem thickness, and chlorophyll content were measured weekly, and the storage root yield was determined at the end of the experiment. The results showed a significant effect of the N treatments on plant growth, chlorophyll content, vine length, leaf area index and storage root yield. The chlorophyll content and vine length increased with an increase in the N rate. However, an inverse relationship was observed between storage root yield and N rates; the highest yield was recorded for the 50 kg/ha N treatment and the lowest yield was recorded for the 200 kg/ha N applied. Therefore, a rate of 50 to 100 kg/ha N is recommended for the production of orange-fleshed sweet potatoes.

Potential of neglected and underutilized tacca tuber (Tacca leontopetaloides) for sustainable food system in Indonesia

Tacca tubers (Tacca leontopetaloides) are a tuber plant variety that is neglected and underutilized. Understanding tacca tubers' nutritional and anti-nutritional composition is necessary as a scientific basis for their development in the food industry. This study aims to evaluate the proximate composition, nutritional, and anti-nutritional compounds of tacca tubers grown in various regions in Indonesia, in particular Garut, Bangkalan, and Sumenep. As a result, the growing location did not affect the proximate composition (crude protein, ash, crude fiber, and fat) of tacca tubers except for water content. Significant differences were observed in starch content (25.77-32.43 %), vitamin C (11.85-14.32 mg/100 g), and vitamin E (0.25-0.42 mg/100 g). The growing location also significantly influences tacca tubers' mineral components (phosphorus, magnesium, calcium, iron, copper, zinc, sodium, and potassium). In addition, anti-nutritional compounds such as phytic acid (633.25-538.80 mg/100 g), tannin (45.43-64.03 mg/100 g), oxalate (201.14-338.01 mg/100 g), cyanide (2.17-3.05 mg/100 g), alkaloids (253.68-487.91 mg/100 g) and saponins (97.54-105.24 mg/100 g) in tacca tubers identified in different amounts at each growing location. In conclusion, tacca tubers Indonesia from Garut contain a high starch component. This potential can be an energy source, especially for coastal communities. Thus, tacca tubers can support creating a sustainable food system in Indonesia.

Test results of new breeding potato hybrids in the conditions of the Volga-Vyatka region

In the period from 2016 to 2022 in the conditions of the Kirov region, an assessment of hybrid potato combinations was carried out according to the most important traits - high productivity and yield, marketable and consumer qualities of tubers. New potato hybrids bred by the Falenki Breeding Station – branch of the FARC North-East were used as the objects of the research: 6-17 (‘Gornyak’ x ‘Manifest’); 15-17 (428-05 x ‘Manifest’); 33-17 (132-07 x ‘Manifest’); 72-17 (‘Gornyak’בIrbitsky’); 78-17 (‘Udacha’ x 428-05); 120-17 (‘Utyonok’בReggi’); 25-16 (‘Kupalinka’ x 428-05). They were noted as the most promising ones according to the results of the research of 2016-2022. The medium-early ‘Nevsky’ cultivar approved for use in the Kirov region was used as a standard. According to the methodological guidelines of the potato breeding process, phenological observations, productivity assessment (on day 65), total and commercial yields were carried out in the nursery, and the chemical composition of tubers was determined. As a result, on average, over three years of testing for a complex of economically valuable traits, a promising breeding number 33-17 was identified – a significant excess of the total yield (29.9 t/ha) over the standard ‘Nevsky‘ cultivar was 14.6 t/ha. The tubers are oval with a red, slightly reticulated skin, the eyes are small, unpainted, the flesh is white. In addition, when evaluating the productive capabilities of potato hybrids, the coefficient of adaptability of breeding number 33-17 was 1.40, which makes it possible to recommend it for cultivation in this region in order to obtain stable yields.

Mineral Quantitation of Irish Potato (Solanum tuberusom) Treated with Maca (Lepidium meyenii) During Storage

Irish potato (Solanum tuberusom) has contributed to human diet for thousands of years, first in the Andes of South America and then in the rest of the world. Potato is rich in potassium which reduces the risk of cardiovascular disease. Maca (Lepidium meyenii) contains macamides which are thought to have antioxidant effects. Prolonged storage of Irish potatoes is the stage at which good quality tubers are most difficult to maintain because of the transformations occurring at that time lead to quantitative changes in the composition of tubers. This work was designed to quantify potassium along aside with some minerals in Irish potato during storage with aqueous solution of maca flour. In the storage process, potatoes are affected by two negative factors, i.e., high (room) temperature, light and physiological activities in the tuber. The values obtained for Irish potato treated with aqueous maca 1:10 mL distilled water (MA1) and untreated potato as control (CTRL) respectively are potassium (173.85 and 93.67 mg/100 g), sodium (99.74 and 39.59 mg/100 g), magnesium (14.20 and 12.37 mg/100 g), phosphorus (56.00 and 39.00 mg/100 g), zinc (0.34 and 0.30 mg/100 g), manganese (0.39 and 0.33 mg/100 g) and copper (0.01and 0.01 mg/100 g). MA1 differs significantly (p < 0.05) from CTRL for potassium, sodium and magnesium phosphorus and zinc while there was no significant difference for manganese and copper. These results indicate that treating potato with low concentration of aqueous maca helps to retain minerals composition during storage.

Effects of postharvest management on the nutrient content of potato (Solanum tuberosum) tubers during storage

An experiment was performed to assess the effect of two plant powders and six storage methods on the proximate composition of potato tubers stored under ambient conditions to find a simple technology for storing potato tubers with a minimal nutrient degradation to reduce postharvest losses by smallholder farmers. Two plant powders and six storage methods were used in the study, which was designed as a 3 x 6 factorial experiment laid out in a completely randomized design (CRD) and replicated three times. The application of neem leaf powder to potato tubers and storage in the pit significantly (P ≤ 0.05) maintained protein (5.65%), fat (0.91%), fiber (0.75%), ash (2.70%), dry matter (30.63%), moisture (69.34%), and carbohydrate (20.62%) contents. Similarly, the pit storage method has influenced the nutrient content significantly (P ≤ 0.05) and is the best method for retaining protein (5.74%), fiber (0.78%), ash (2.81%), and moisture (69.83%) contents of potato tubers during storage under ambient conditions, and there is no significant (P > 0.05) interaction effect between the plant powder and the storage method. The study has found that the neem leaf powder and the pit storage significantly preserved the nutrient content of potato tubers during the four weeks of storage, which helped minimize postharvest losses. Keywords: basket, carton, floor, ginger, jute bag, neem, pit, polypropylene bag

Promising potato hybrids in Siberia

The results of studying potato hybrids in the nurseries of preliminary and competitive variety trials are presented. The research was conducted in 2018–2022 in the Krasnoyarsk Territory in grain and fallow crop rotation. The soil of the experimental plot is represented by leached chernozem, low- and medium-moist heavy loam of granulometric composition. Experiment design, yield recording and data processing were carried out in accordance with the generally accepted recommendations for work with the crop. Based on the Selyaninov hydrothermal coefficient, the weather conditions of the vegetation periods of the years of research can be characterized as slightly arid. The HTC was 1.1 in 2019 and 2021, in 2020, 2022 – 1,3. According to the results of the preliminary variety trials, lines A-114, A-326, A-529, A-635a exceeded or were at the level of the standard variety Krasnoyarsky Ranniy by the number of marketable tubers and yield. During 4 years of research in the nursery of competitive varietal trial, the studied breeding lines on average formed yields at the level or higher than the standard varieties. According to the elements of the yield structure in the competitive variety trial lines A-114, A-529 significantly exceeded the standard variety in marketability, as well as had a smaller number and weight of unmarketable tubers. Based on the results of the evaluation in 2019–2021 of the chemical composition of tubers for dietary and functional food, lines with low starch content (up to 14%) are proposed: A-114 (12.2%), А-672а (9.9), А-635а (12.7%). Based on the study in 2019–2022 of the line A-114 in competitive trials, preliminary and production multiplication, ecological assessment, application materials for admission to use and protection of the new potato variety Akrux were submitted to the State Variety Commission.

Biochemical Composition of Tubers of New Russian Potato Cultivars

Biochemical Composition of Tubers of New Russian Potato Cultivars

Formation of yield and quality of topinambur tubers with different planting techniques

To expand the production of topimanbur in the Russian Federation, it is necessary to develop adaptive cultivation technologies in various regions of the country. Field research was carried out on the territory of the educational and scientific experimental field of the Perm State Technical University. Three variants of the planting scheme were studied: 70x30, 70x40 and 70x50 cm and three variants of the weight of the planting tuber: 20-40 g, 41-60 g and 61-80 g. The applied agrotechnical measures are generally accepted for the non–Chernozem zone. The technology of planting topinambur is a comb. The research results show that with planting schemes of 70x30, 70x40 and 70x50 cm, topinambur forms the exact yield of tubers – 18.3-19.3 t/ha. When used for planting tubers weighing 41-80 g, the yield increases by 1.1-1.7 t/ha, compared with the planting fraction of 21-40 g, due to an increase in plant density by 0.1 pcs. /m2. Biological yield indicators fully reflect the actual yield. Under the studied planting schemes, it was also the same and amounted to 2002.6-2177.9 g/m2, and when planted with larger tubers, it was 271.7-277.0 g/m2 higher than tubers of 20-40 g. The proportion of tubers of the small fraction – 48-59 % prevails in the Jerusalem artichoke crop. The share of the food fraction is 8-16 %. The fractional composition of tubers in the crop does not depend on the mass of the planting tuber. The share of planting tubers in the harvest with schemes 70x30 and 70x40 cm is higher by 6-8 %. A higher dry matter content in tubers was observed when planting tubers weighing 20-60 g – 21.3-21.6 %, and vitamin C – when planting tubers 61-80 g – 14.5 mg/kg. The planting scheme does not affect the biochemical composition of topinambur tubers.

Nutritional and anti-nutritional compositional analysis of transgenic potatoes with late blight resistance.

Late blight, caused by the pathogen Phytophthora infestans, is a devastating disease affecting potato production globally, with adverse effects in Africa where limited access to fungicides exacerbates its impact. Outbreaks of late blight lead to reduced yields and substantial economic losses to potato farmers and agricultural systems. The development of resistant potato varieties, tailored to African agroecological conditions, offers a viable solution in mitigating the devastating effects of late blight on potato cultivation. Leading to this study, two consumer-preferred varieties, Victoria and Shangi, with high susceptibility to late blight were targeted for conferring late blight resistance through genetic engineering. This was achieved by inserting R genes from wild relatives of potato displaying resistance to the disease. The intended effect of conferring resistance to the late blight disease has been consistently observed over twenty experimental field trials spanning 8years at three locations in Uganda and Kenya. In this study, we assessed whether the genetic transformation has led to any significant unintended effects on the nutritional and anti-nutritional composition of potato tubers compared to the non-transgenic controls grown under the same agroecological conditions. The compositional assessments were conducted on commercial-size potato tubers harvested from regulatory trials at three locations in Uganda and Kenya. Statistical analysis was conducted using two-way analysis of variance comparing transgenic and non-transgenic samples. Overall, the results showed that the transgenic and non-transgenic samples exhibited similar levels of nutritional and antinutritional components. Variations detected in the levels of the analysed components fell within the expected ranges as documented in existing literature and potato composition databases. Thus, we conclude that there are no biologically significant differences in the nutritional and anti-nutritional composition of transgenic and non-transgenic potato tubers engineered for resistance to late blight.

Effect of mineral fertilizers on quality and storability of potatoes

Potato is one of the most valuable crops in world agriculture. Potato quality and its storability during storage are influenced by many factors: growing conditions: moisture, heat and light supply, variety features, mineral nutrition. We studied the influence of variety and fertilizers on the quality and storability of tubers in the conditions of North-West Russia. Potato varieties of foreign selection of different maturity dates, suitable for processing into "crispy potatoes" (chips, french fries, potato grits), released in the region, were used as an object of research. The doses of complex mineral fertilizers and microfertilizers, their effect on yield, technological qualitative and biochemical parameters of potato tubers served as the subject of research. The study was carried out under the conditions of field experiment and laboratory. Data on the influence of variety and fertilisers on quantitative and qualitative indicators of potato tuber yield and their safety during long-term storage were obtained. The comparative response of potato varieties of different groups of rapid maturity to variants of dosage of complex mineral fertilizers by formation of yield and qualitative composition of tubers has been established. The use of complex mineral fertilizers Green-Go 18-18-18+1.3 Mg0+micro and the REXOLIN ABC microfertilizers on different groups of potato varieties at maturity dates is effective and leads to an increase in yield and quality of production. The studied forms of mineral fertilizers have a positive effect on the biochemical composition of potato tubers: the content of dry matter in tubers increases, as well as starch and reducing sugars.

EFFECT OF MYCORRHIZAL FORMULATION MYCOFRIEND ON POTATO PRODUCTIVITY

The purpose was to investigate the effect of mycorrhizal formulation Mycofriend on biometric parameters, productivity and biochemical composition of potatoes, as well as to determine the economic effect of its use. Methods. Field, laboratory, statistical. The study was conducted at the Institute of Vegetable and Melons Growing of NAAS. Results. The results on the effect of different doses of mycorrhizal formulation Mycofriend (complex of mycorrhizal fungi: Glomus VS, Trichoderma harzianum; microorganisms supporting the formation of mycorrhiza and rhizosphere of plants: Streptomyces sp., Pseudomonas fluorescens; phosphate-mobilizing bacteria: Bacillius megaterium var. phosphaticum, Bacillus subtilis, Bacillus muciloginosus, Enterobacter sp) on biometric parameters, yield and its constituents and biochemical composition of tubers are presented. Mycofriend clearly tend to increase the potato yield. On average, it was higher than the control (33.6 t/ha) by 4.6 t/ha and 4.4 t/ha at Mycofriend concentrations of 1.0 L/t and 2.0 L/t, respectively. Mycofriend also increased biometric parameters in comparison with the control (without treatment). In particular, the plant height after treatment of tubers with 1.0 L/t and 2.0 L/t increased by 0.19 m and 0.26 m, respectively; at the same time, the plant weight was also increased by 278 g and 590 g, respectively. There were upward trends in the contents of starch (by 1.29–3.03%) and ascorbic acid (by 4.08–5.94 mg/100 g) in tubers. Additional costs in the experiments ranged UAH 5935 to UAH 18,67 1/ha. However, a reduction in the prime costs by 0.17–0.33 UAH/kg was achieved, leading to a corresponding increase in the profitability of cultivation by 8.8–12.8 %. The most economically justified dose of the formulation was 1.0 L/t. Conclusions. It is possible to treat potato tubers with mycorrhizal formulation Mycofriend at a dose of 1.0 L/t and 2.0 L/t during pre-planting preparation, which significantly improves biometric parameters (plant height and vegetative weight). The highest gain in the yield was noted with 1.0 L/ha of Mycofriend – 4.6 t/ha. Here, the most significant decrease in the prime costs and increase in the profitability were observed.

Hydroponic potato production in wood fiber for food security

The resilience of global food security is a critical concern. Facing limited access to land and potential disruption of the food markets, alternative, scalable, and efficient production systems are needed as a complementary buffer for maintenance of food production integrity. The purpose of this study was to introduce an alternative hydroponic potato growing system where potatoes are grown in bare wood fiber as a growing medium. A system utilizing drip irrigation and plastic bags as containers was tested for three different types of wood fiber, two cultivars and two fertigation strategies. Implementation of the system resulted in ~300% higher tuber production when compared to the local conventional farming. Mineral composition of the tubers obtained from hydroponic system was similar to the composition of tubers grown in the field and revealed potential for biofortification. In addition, a fertigation strategy where the two application points were separated across the root zone resulted in tubers with dry matter content comparable to the potatoes grown in soil. The recyclability, reusability, and simplicity of this solution may encourage its application for improving security of food production in selected areas of the world as well as its utilization in urban agriculture.

Nutrients, the Bioavailability of Micronutrients and Antinutrient Composition of African Yam Bean Tubers

Despite the huge nutritional and nutraceutical benefits associated with the consumption of African yam bean (AYB) seeds, AYB tubers are still underutilized in Nigeria, they are left to rot in farmers’ fields. To create awareness about their nutrient density and provide information on the bioavailability of micronutrients in the tubers of AYB accessions, raw tubers of TSs 9, TSs 60 and TSs 93 were analyzed using standard laboratory procedures. The AYB tubers had the following composition on a fresh weight basis: crude protein (7.55-8.27%), carbohydrate (9.36-11.12%), crude fat (0.18-0.22%), crude fibre (0.33-0.750%), crude ash (0.44-0.59%), and moisture (79.76-80.82%). The fresh tubers were rich in minerals: potassium (532.88-557.80 mg/100 g), calcium (205.75-467.50 mg/100 g), magnesium (124.75-168.50 mg/100 g), iron (15.71-27.30 mg/100 g), zinc (8.57-14.80 mg/100 g), and manganese (0.68-1.98 mg/100 g). The phytate: Zn and the phytate: Fe molar ratios indicated the bioavailability of Fe and Zn in the raw AYB tubers. The results of this study indicate that AYB tubers are good sources of protein, energy and bioavailable Fe and Zn and should be utilized for human diets and livestock feed. With good processing, AYB tubers could contribute to food and nutrition security. There is a need for research on food products developed from AYB tubers to enhance their utilization and large-scale production in Nigeria.&nbsp

Raman spectroscopy detects chemical differences between potato tubers produced under normal and heat stress growing conditions.

Potato is the most consumed vegetable worldwide. Potato tubers contain water, starch, proteins, minerals, and vitamins. The amounts of these chemicals depend on the cultivar and growing location. When potatoes are exposed to high temperatures during the growing period, tuber yield and quality are detrimentally affected; however, there is limited knowledge about the influence of high temperatures on tuber chemical composition. With temperatures rising around the globe, the reaction of potato cultivars to high temperatures is increasingly important, and heat-induced changes, including changes in the chemical composition of tubers, should be considered. The Texas A&M University Potato Breeding Program has been selecting potato clones under high-temperature conditions for many years. Several released cultivars are considered heat-tolerant based on high marketable yields and low internal and external tuber defects. In this study, we used Raman spectroscopy (RS), an analytical tool, to determine whether heat stress causes changes in the chemical composition of tubers of ten potato cultivars. RS is a non-invasive method that requires less time and labor than conventional chemical analysis. We found drastic changes in the intensities of vibrational bands that originate from carbohydrates in the spectra acquired from tubers of heat-stressed plants compared to tubers produced by potato plants grown under normal conditions. These results demonstrate that RS could be used as a replacement or complement to conventional chemical analysis to inspect the effect of heat stress on tuber chemical composition.

EFFECT OF PRETREATMENT OF POTATO TUBERS WITH A BIO PREPARATION ON THEIR BIOCHEMICAL COMPOSITION AND YIELD

The authors presented data on the effect of the biological product Phytop 8.67 based on bacteria of the genus Bacillus on the biochemical composition and yield of tubers during the pre-planting treatment of potatoes in 2018. The authors conducted experiments on the early-ripening potato variety Rosara in the soil-climatic zone of the forest-steppe in the conditions of leached chernozem of the experimental fields of the Educational and Production Farm (EPF) “Michurintsev Garden.” At pre-planting treatment of potato tubers, Phytopom 8.67 mass fraction of dry matter was 17.62%, which was significantly higher than the control variant. In the experimental version, there was a significant increase in protein content in potato tubers from 14.4% to 15.9% relative to the control variant, while the range of ash elements decreased. The authors note that using the bio preparation Phytop 8.67 reduced the infection of tubers with sclerotia and other forms of Rhizoctonia Solani Kuhn by three times compared with the control. The biological effectiveness of the application was 66.4%.

Medicinal effect of carrot and storage technologies in modern refrigerated warehouses

This article shows the importance of the local carrot root fruit in the national economy, which is loved by the population today. Its branches of use for the food industry, i.e. cases of maximum preservation of its medicinal properties and chemical composition compared to other types of vegetables, in the production of various products in a fresh yellow appearance, storage and processing for certain periods, have been studied. In addition, the superiority levels of carrots over other products, as well as the main chemical composition of carrot tubers in any form of use, the amount of dissolved dry matter in the tubers and the level of acidity in the juice were studied. The dependence of the storage period of carrots in the freshly cut state and the long-term storage period, in addition, the main technological parameters in the process of long-term storage of carrot tubers in modern refrigerated warehouses are presented. Information on the total amount of natural weight loss during initial cooling and long-term storage with changes in quality indicators depending on the temperature and relative humidity of the air in the cooling chamber is presented.

Application of the agrochemical "Tatfarmat (marka A)" on potatoes

Relevance. With the increasing interest of agricultural producers in biological farming, there is a need to provide farmers with affordable and effective biological preparations. In the current realities, under the conditions of sanctions, special attention should be paid to domestic manufacturers of biological products.Methods. The effectiveness of the use of a new microbiological fertilizer "Tatfarmat (marka A)" for presowing treatment of potato tubers of the Salsa variety of domestic selection was evaluated. The experiment was carried out on gray forest soil. We studied such indicators as potato yield, the number of tubers (from 1 bush and from 1 m2), the average mass of marketable tubers (from 1 bush and from 1 m2), the fractional composition of tubers (in %) and the content of starch and vitamin C in tubers.Results. The positive effect of the biopreparation "Tatfarmat (marka A)" on the quantitative and qualitative indicators of potatoes was revealed. The yield in the variants with the use of microbiological fertilizer increased by 4.9–14.8% compared to the control, the number of tubers (from 1 m2) — by 7.8–46.9%, the average mass of marketable tubers (from 1 m2) — by 11.4–33%. The share of seed and food fractions of tubers increased by 0.5–3.6% and 1.5–3.1%, respectively. There was an increase in the content of starch in dry matter by 0.7–4.7%. The content of vitamin C in tubers increased by 9–19%.

Metabolite profiling of tubers of an early- and a late-maturing potato line and their grafts

IntroductionEarliness of tuberisation and the quality of potato tubers are important traits in potato breeding. The qualitative traits rely on the metabolite profile of tubers, which are storage organs and net importers of assimilates. Thus, the quality of tubers largely depends on the metabolites transported from leaves to developing tubers.ObjectivesTo test the influence of canopy on the quality of tubers by metabolite profiling of tubers of an early- and a late-maturing potato line and their grafts.MethodsPotatoes were grown under greenhouse conditions, grafted and the tubers harvested at the end of the scions’ vegetation period. Metabolite profiling of freshly harvested tubers was performed using gas chromatography coupled with mass spectrometry. Statistical analyses were applied to determine the significant differences between the different tubers.Results99 metabolites were identified and an additional 181 peaks detected in chromatograms, out of which 186 were polar and 94 non-polar compounds. The concentrations of 113 metabolites were significantly different in the tubers from the early-maturing CE3130 and the late-maturing CE3027 line. Hetero-grafting resulted in considerable changes in the metabolite content of tubers. Especially, the effect of CE3027 on the metabolite composition of tubers formed on CE3130 rootstocks was readily apparent. Nevertheless, many compounds were present at similar levels in the tubers of hetero-grafted plants as was found in the tubers of their scion counterparts.ConclusionHetero-grafting resulted in many compounds at similar concentrations in rootstock tubers as in scion tubers suggesting that these are transported from the source leaves to tubers.

Exogenous naphthaleneacetic acid alleviated alkalinity-induced morpho-physio-biochemical damages in Cyperus esculentus L. var. sativus Boeck.

Cyperus esculentus L. var. sativus Boeck (commonly called Chufa) is a perennial species that produces nutritious underground tubers and contributes to the diet and health of human worldwide. However, it is salt-sensitive and its adaptation to salinity stress remains an enigma. Naphthaleneacetic acid (NAA) plays a vital role in regulating plant salt stress tolerance. Thus, we aimed to investigate the impact of NAA (150 mg/L) application on growth and physio-biochemical response mechanisms of Chufa plants to different levels of salinity stress (0-, 90-, and 180 mM of alkaline stress ([1:1 ratio of Na2CO3 and NaHCO3]). In response to increasing stress levels, shoot-root growth decreased, whereas malondialdehyde (MDA), hydrogen peroxide (H2O2), osmolytes (soluble protein, proline, and soluble sugars), and activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) significantly increased. Alkalinity led to significant increase in Na+ and Cl-, but decrease in Mg2+ concentration in both roots and leaves; however, K+ decreased significantly in leaves under both stresses. Additionally, and. levels, nitrate reductase (NR) activities, and glutamate synthase (GOGAT) decreased significantly. However, glutamine synthetase (GS) increased non-significantly at 90 mM but declined at 180 mM. Foliar NAA application reduced Na+ and Cl-, MDA, and H2O2 but increased photosynthetic pigments, K+ and Mg2+, osmolytes, nitrogen (N) metabolism, and upregulating the enzymatic antioxidant system to reduce oxidative stress under alkaline conditions. Hence, our findings manifest that NAA application is an effective strategy that can be utilized to enhance tolerance of chufa plants to alkaline stress. Future studies should explore whether NAA can positively alter the nutrient composition of chufa tubers at deeper molecular levels, which might offer solutions to nutritious problems in developing countries.