Tuber Starch Content Research Articles

Potato Tuber Yield and Quality Under Different Potassium Application Rates and Forms in West Siberia

Abstract Potato cultivars have different strategies for dealing with potassium (K) deficiency in soil, and their response to different forms and rates of K fertilisation may vary because of differences in soil K availability. This study was performed to evaluate the effect of K fertilisation rates (0, 30, 60, 90, 120 and 150 kg K/ha) on tuber yield and quality (dry matter, starch, sugar and ascorbic acid content, taste) of two potato cultivars (Roco and Rosara) grown in the microplot field experiment on Luvisol in the forest-steppe zone in southern West Siberia, Russia (NL 54.422106, EL 83.160257). The tuber yield of both potato cultivars increased with increase in K application rate up to 2.1 and 2.9 kg/m2 for Roco and Rosara, respectively. Sugar content, averaging 3.5%, was mostly determined by cultivar; however, in both cultivars it tended to decrease with increasing K application rate. The application of K fertiliser in the form of sulphate as compared to chloride increased dry matter content from 22.4 to 23.8% and ascorbic acid content from 13.2 to 14.6 mg/100 g fresh mass. Starch content of potato tubers averaged 59.7 ± 4.8% over all K fertilisation variants, with cultivar responses being different. Potassium application rate did not affect Roco tubers’ taste, while improving Rosara tubers’ taste under moderate application rates. The results underscore the importance to adjust fertiliser recommendations concerning potassium application rates and source on the basis of biological requirements and intended utilization of individual potato cultivars

Karakterisasi Umbi dan Pati Lima Kultivar Ubi Kayu (Manihot esculenta)

<em>The aim of this research was to evaluate the chemical composition of tubers and cassava starch and cassava starch physical Masni District. This study consists of three (3) stages: preparation of materials and chemical characterization of fresh tubers, starch extraction and chemical and physical characterization of cassava. Extraction is done by using a 3:1 ratio of water and tubers. The results showed that the starch content of the fresh tubers ranged from 13.12% to 46.09% while the starch content of cassava starch between 81.40% to 89.55%. Amylose starch levels ranged from 12.28% to 27.38% while the amylopectin content ranged from 72.61% to 87.71%. Starch granule shape is round, round cut, elliptical with a size ranging between 5-25 ?m, the temperature ranges from 65-69<sup>o</sup>C gelatinization and power development starches ranged from 1.42 to 26.65.</em>

Prospects and Potential Uses of Genomic Prediction of Key Performance Traits in Tetraploid Potato.

Genomic prediction is a routine tool in breeding programs of most major animal and plant species. However, its usefulness for potato breeding has not yet been evaluated in detail. The objectives of this study were to (i) examine the prospects of genomic prediction of key performance traits in a diversity panel of tetraploid potato modeling additive, dominance, and epistatic effects, (ii) investigate the effects of size and make up of training set, number of test environments and molecular markers on prediction accuracy, and (iii) assess the effect of including markers from candidate genes on the prediction accuracy. With genomic best linear unbiased prediction (GBLUP), BayesA, BayesCπ, and Bayesian LASSO, four different prediction methods were used for genomic prediction of relative area under disease progress curve after a Phytophthora infestans infection, plant maturity, maturity corrected resistance, tuber starch content, tuber starch yield (TSY), and tuber yield (TY) of 184 tetraploid potato clones or subsets thereof genotyped with the SolCAP 8.3k SNP array. The cross-validated prediction accuracies with GBLUP and the three Bayesian approaches for the six evaluated traits ranged from about 0.5 to about 0.8. For traits with a high expected genetic complexity, such as TSY and TY, we observed an 8% higher prediction accuracy using a model with additive and dominance effects compared with a model with additive effects only. Our results suggest that for oligogenic traits in general and when diagnostic markers are available in particular, the use of Bayesian methods for genomic prediction is highly recommended and that the diagnostic markers should be modeled as fixed effects. The evaluation of the relative performance of genomic prediction vs. phenotypic selection indicated that the former is superior, assuming cycle lengths and selection intensities that are possible to realize in commercial potato breeding programs.

Agroecological Efficiency of Organic and Mineral Fertilizers under Frozen Soil Conditions

Investigations were carried out on permafrost taiga soil in Central Yakutia in a field factorial experiment with a wide range of rates and combinations of cattle manure and mineral fertilizers. The advantage of an organo-mineral fertilizer system in N60P60K60 rates was shown against a background of 40 t of manure per hectare, which provides, under watering conditions, potato tuber yields of 18 t per hectare with starch content of 13.9%, which is 47.8% higher than in the control without fertilizer use. The yield of potatoes under the organic system with annual manure rate of 40 t per hectare was at the same level with the mineral system, but tubers contained more starch, 12.8%. It has also been established that organo-mineral and organic systems have a positive effect on the agrochemical properties of the soil, optimize its humus state and phosphate and potassium regimes. For the mineral fertilizer systems in rates of N60P60K60, the yield increment was significant, but it did not exceed 17.8% with a lower starch content in tubers, 11.5%, and a negative balance of humus, phosphorus, and potassium in the soil.

Characterization and comparative study of starches from seven purple sweet potatoes

Sweet potato starch has great edible and economic value and has been widely studied. Starches from different varieties have significantly different properties. Previous studies are focused on white, yellow and orange sweet potato. In this study, starches were isolated from purple sweet potato variety Ningzi 1 and six advanced breeding lines with different genotypes, their structural and functional properties were investigated and compared. Seven starches all had round, polygonal, oval and semi-oval shapes with central hila, but showed different granule sizes. The starch content in dry root tubers varied from 40.1 to 55.1%. The apparent amylose content ranged from 24.6 to 31.0%. The seven sweet potatoes all had CA-type starch. The swelling power and water solubility at 95 °C ranged from 22.5 to 29.0 g/g and 13.1 to 16.9%, respectively. The starches displayed a two peak gelatinization thermogram, the first peak temperature ranged from 64.1 to 69.0 °C and the second peak temperature ranged from 73.5 to 80.8 °C. The peak viscosity, hot viscosity, breakdown viscosity and setback viscosity varied from 2535 to 3750 mPa s, 1517 to 2450 mPa s, 1018 to 1622 mPa s, and 474 to 1036 mPa s, respectively. The seven starches had different hydrolysis degrees to porcine pancreatic α-amylase and Aspergillus niger amyloglucosidase. All the starches had high resistance to the in vitro digestion. This study could provide important information for the utilization of purple advanced breeding lines in breeding and food and nonfood industries.

Impact of Biochar Addition on Productivity and Tubers Quality of Some Potato Cultivars Under Sandy Soil Conditions

THE PRESENT study was carried out during the two summer seasons of 2016 and 2017 to study the effect of biochar application rates (0, 1.25, 2.5 and 5 m3/feddan (fed.) = 4200 m2) on productivity and tubers quality of three potato cultivars i.e., Accent, Cara and Spunta grown under sandy soil conditions. Cara and Spunta cultivars recorded the highest values of morphological traits, leaf content of Ca, Mn and Cu, as well as tuber yield and quality. Cara cultivar recorded the maximum dry weight of different plant parts, while Spunta cv. recorded the highest values of photosynthetic pigments concentrations in the leaf tissues and the highest tuber starch content. Accent cv. recoded the lowest values of the last mentioned parameters and the lowest tuber nitrate content. Plant growth, leaf photosynthetic pigments and minerals content (N, P, K, Ca, Fe, Zn, Mn, and Cu), yield and its components, as well as tuber quality were significantly increased with increasing biochar application rates up to 5 m3/fed. Treated the three tested potato cultivars plants with different application rates of biochar increased plant growth, leaf photosynthetic pigments, minerals content and tuber yield and its components, compared to those untreated with biochar. Adding biochar at rates of 2.5 or 5 m3/fed. to the three tested potato cultivars Considerably gave the lowest values of leaf nitrate content. Treating Cara cultivars with biochar at rate of 5 m3/fed. gave the highest values of gross and net return, as well as benefits ratio, followed by adding 5 m3/fed. to Spunta plants. Finally, adding biochar to potato plants grown in sandy soil conditions obviously improves potato plant growth, plant chemical compositions, tuber yield and its components, with good tubers quality and increasing net return of potato production and keeps the environment less polluted.

Genotype x environment interaction, stability and co-heritability of tuber internal quality traits in potato (Solanum tuberosum L.) cultivars in Ethiopia

Potato ( Solanum tuberosum L.) is a crop with the potential of ensuring food and nutrition security in Ethiopia because it yields more edible energy, protein and dry matter per unit area and time than cereal crops. In Ethiopia, potato varieties were developed mainly to fit preparation of traditional foods. However, French fries and chips are the emerging products of tubers that demanded breeders to identify cultivars fit to the emerging economics of production until specific varieties are developed for specific end products. This study was conducted with the aim of identifying wide adaptable potato varieties for internal quality of tubers, and to determine stability, coheritability and correlation among traits. A total of 17 improved and two farmers’ cultivars namely, Jarso and Bete were evaluated in three locations from 2012 to 2014 using a randomized complete block design with three replications. Specific gravity and starch content of tubers were significantly influenced by the interaction of cultivar x location x seasonwhile dry matter was significantly affected only by cultivar, location and growing season. The 15 improved varieties produced tubers with >1.08 gcm -3 ,>23% and >13%specific gravity, dry matter and starch content, respectively, that were suitable for French fries and chips processing, but the two farmers’ cultivars (Jarso and Bete) with tubers 0.96) with strong correlation (r>0.98) and high coheritability (>79.85%) of traits with specific gravity. Moreover, high coheritability was observed (86.65%) for the three traits as covariate. This suggests that tuber specific gravity is an appropriate measurement in selection of varieties to determine the internal quality of tubers for processing. The significant effect of genotype x environment interaction on specific gravity and starch content suggests the importance of testing varieties across locations over years to identify high performing and widely adaptable varieties to benefit producers, processors and other consumers. Keywords: Chips, dry matter content, French fries, specific gravity, starch content

Quantitative trait loci for tuber blackspot bruise and enzymatic discoloration susceptibility in diploid potato

Tuber tissue discolorations caused by impact (blackspot bruising) and enzymatic discoloration (ED) after tuber cutting are crucial quality traits of the cultivated potato. To understand the complex genetics of the traits, quantitative trait locus (QTL) analysis using diploid mapping population and diversity array technology (DArT) markers was performed. The phenotypic assessment included the complex evaluation of blackspot bruising susceptibility through two methods: rotating drum (BRD) and falling bolt (BFB) in combination with the evaluation of enzymatic discoloration. Because of observed in-practice relationship between bruising susceptibility and tuber starch content (TSC), analysis of starch content-corrected bruising susceptibility (SCB) was performed. QTLs for bruising were detected on chromosomes I, V with both test methods. The rotating drum method enabled the detection of additional QTLs on chromosomes VIII and XII. Analysis of SCB enabled the identification of the major QTL on chromosome V and two weaker QTLs on chromosomes VIII and XII, independently of starch content. The QTL for bruising detected on chromosome I overlapped with the most significant QTL for tuber starch content. This QTL was not significant for starch content-corrected bruising susceptibility, and the effect of the QTL on chromosome V was enhanced for this trait. The QTL analysis of ED revealed the contribution of seven QTLs for the trait, located on six chromosomes, including these detected for the first time: a major locus on chromosome V and minor QTLs on chromosomes VII and X, which were specific for the trait. The QTL for ED on chromosome VIII was co-localized with the marker for polyphenol oxidase (POT32). The phenotypic correlation between bruising and ED was confirmed in QTL analyses of both traits, and the QTLs detected for these traits overlapped on chromosomes I, V, and VIII. Our results should provide a basis for further studies on candidate genes affecting blackspot bruise susceptibility and enzymatic discoloration.

Physical mapping of QTL for tuber yield, starch content and starch yield in tetraploid potato (Solanum tuberosum L.) by means of genome wide genotyping by sequencing and the 8.3\xa0K SolCAP SNP array

BackgroundTuber yield and starch content of the cultivated potato are complex traits of decisive importance for breeding improved varieties. Natural variation of tuber yield and starch content depends on the environment and on multiple, mostly unknown genetic factors. Dissection and molecular identification of the genes and their natural allelic variants controlling these complex traits will lead to the development of diagnostic DNA-based markers, by which precision and efficiency of selection can be increased (precision breeding).ResultsThree case-control populations were assembled from tetraploid potato cultivars based on maximizing the differences between high and low tuber yield (TY), starch content (TSC) and starch yield (TSY, arithmetic product of TY and TSC). The case-control populations were genotyped by restriction-site associated DNA sequencing (RADseq) and the 8.3 k SolCAP SNP genotyping array. The allele frequencies of single nucleotide polymorphisms (SNPs) were compared between cases and controls. RADseq identified, depending on data filtering criteria, between 6664 and 450 genes with one or more differential SNPs for one, two or all three traits. Differential SNPs in 275 genes were detected using the SolCAP array. A genome wide association study using the SolCAP array on an independent, unselected population identified SNPs associated with tuber starch content in 117 genes. Physical mapping of the genes containing differential or associated SNPs, and comparisons between the two genome wide genotyping methods and two different populations identified genome segments on all twelve potato chromosomes harboring one or more quantitative trait loci (QTL) for TY, TSC and TSY.ConclusionsSeveral hundred genes control tuber yield and starch content in potato. They are unequally distributed on all potato chromosomes, forming clusters between 0.5–4 Mbp width. The largest fraction of these genes had unknown function, followed by genes with putative signalling and regulatory functions. The genetic control of tuber yield and starch content is interlinked. Most differential SNPs affecting both traits had antagonistic effects: The allele increasing TY decreased TSC and vice versa. Exceptions were 89 SNP alleles which had synergistic effects on TY, TSC and TSY. These and the corresponding genes are primary targets for developing diagnostic markers.

Simultaneous silencing of isoamylases ISA1, ISA2 and ISA3 by multi-target RNAi in potato tubers leads to decreased starch content and an early sprouting phenotype.

Isoamylases hydrolyse (1–6)-alpha-D-glucosidic linkages in starch and are involved in both starch granule formation and starch degradation. In plants, three isoamylase isoforms with distinct functions in starch synthesis (ISA1 and ISA2) and degradation (ISA3) have been described. Here, we created transgenic potato plants with simultaneously decreased expression of all three isoamylases using a chimeric RNAi construct targeting all three isoforms. Constitutive expression of the hairpin RNA using the 35S CaMV promoter resulted in efficient silencing of all three isoforms in leaves, growing tubers, and sprouting tubers. Neither plant growth nor tuber yield was effected in isoamylase-deficient potato lines. Interestingly, starch metabolism was found to be impaired in a tissue-specific manner. While leaf starch content was unaffected, tuber starch was significantly reduced. The reduction in tuber starch content in the transgenic plants was accompanied by a decrease in starch granules size, an increased sucrose content and decreased hexose levels. Despite the effects on granule size, only little changes in chain length composition of soluble and insoluble glucose polymers were detected. The transgenic tubers displayed an early sprouting phenotype that was accompanied by an increased level of sucrose in parenchyma cells below the outgrowing bud. Since high sucrose levels promote sprouting, we propose that the increased number of small starch granules may cause an accelerated turnover of glucan chains and hence a more rapid synthesis of sucrose. This observation links alterations in starch structure/degradation with developmental processes like meristem activation and sprout outgrowth in potato tubers.

A System for Identification of Potato Varieties Using SNP Dosage

As in autoteraploids, five genotypes are possible in a biallelic locus, allele dosage could be useful for variety identification in potato. DNA sequences of 13 genes associated with tuber yield, tuber starch content or late blight resistance were surveyed for single nucleotide polymorphism (SNP) in eight tetraploid varieties. A total of 193 potential SNPs was found by Sanger-sequencing, of which 58 were measured for nucleotide frequencies using a pyrosequencer. Of the 58 SNPs, 35 yielded distinct clusters, corresponding to allele dosages. Among these, six were highly correlated with another, leaving 29 independent SNP loci for use in variety discrimination. By using dosage scores at the 29 SNP loci, it was possible to differentiate 115 varieties, except for a sport with red tuber skin color, with at least three different SNP dosages. Therefore, using SNP dosages is a simple, fast and reliable tool for variety identification.

Comparative statistical component analysis of transgenic, cyanophycin-producing potatoes in greenhouse and field trials.

Potatoes are a promising system for industrial production of the biopolymer cyanophycin as a second compound in addition to starch. To assess the efficiency in the field, we analysed the stability of the system, specifically its sensitivity to environmental factors. Field and greenhouse trials with transgenic potatoes (two independent events) were carried out for three years. The influence of environmental factors was measured and target compounds in the transgenic plants (cyanophycin, amino acids) were analysed for differences to control plants. Furthermore, non-target parameters (starch content, number, weight and size of tubers) were analysed for equivalence with control plants. The huge amount of data received was handled using modern statistical approaches to model the correlation between influencing environmental factors (year of cultivation, nitrogen fertilization, origin of plants, greenhouse or field cultivation) and key components (starch, amino acids, cyanophycin) and agronomic characteristics. General linear models were used for modelling, and standard effect sizes were applied to compare conventional and genetically modified plants. Altogether, the field trials prove that significant cyanophycin production is possible without reduction of starch content. Non-target compound composition seems to be equivalent under varying environmental conditions. Additionally, a quick test to measure cyanophycin content gives similar results compared to the extensive enzymatic test. This work facilitates the commercial cultivation of cyanophycin potatoes.

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.

Time Course of Starch Biosynthesis Enzymes Activity and Root Tuber Starch of Four Cassava Cultivars

To understand the accumulation rule of cassava root tuber starch, the amylose, amylopectin and total starch content of fresh root tuber, the enzyme activities of sucrose synthase (SuS, EC 2.4.1.13) and sucrose phosphate synthase (SPS, EC 2.4.1.14) of leaves, the enzyme activities of ADP-glucose pyrophosphorylase (AGPase, EC 2.7.7.27), soluble starch synthase (SSS, EC 2.4.1.21) and starch branching enzyme (SBE, EC. 2.4.1.18) of tubers were assessed by using cultivars SC201, SC205, GR891 and GR911 leaves and root tubers during their growth period, respectively. The results as follows: the enzyme activity of leaf SPS and the synthesis direction of SuS showed the highest at August, 2010, however the enzyme activity of the decomposing direction of SuS formed parabolic curve; the enzyme activity of tuber AGPase showed an increased then decreased single peak curve, the enzyme activity of tuber SSS oscillating decreased, while the enzyme activity of SBE was relatively stable; the amylose, amylopectin and total starch contents of fresh cassava tuber were all gradually increased along with the growth period. This research would enrich our knowledge of the time course of amylose, amylopectin and total starch contents of fresh cassava tuber, and above related enzyme activities.

ПОДБОР СРЕДНЕРАННИХ И СРЕДНЕСПЕЛЫХ СОРТОВ КАРТОФЕЛЯ ДЛЯ СТЕПНОЙ ЗОНЫ ЮЖНОГО УРАЛА

The purpose of research is to identify the most adaptive and productive varieties of potatoes for the steppe zone of Southern Urals. The experience was laid by one-factor circuit in 3-fold repetition. The studies were conducted for middle- and middle-early varieties of potatoes domestic and foreign selection. Determined yield, marketability, starch and dry content in potato tubers. At 4 years of data were allocated potato varieties – Artemis (57.8 t/ha), Aerrow (52.0 t/ha) and Romano (49.5 t/ha). Distinguished highest yield of marketable products varieties: Artemis – 97.9%, Tarasov – 97.7%, and Aerrow Romano – 97.4%. The starch content in tubers was measurable by 10.2% (Ed Scarlett) to 16.0% (Kovalenko Memory), and the dry matter content in tubers ranged from 15.6% (Ed Scarlett) to 23.8% (Memory Kovalenko).

UJI DAYA HASIL UBIKAYU (Manihot esculenta Crantz) VARIETAS UJ5 PADA BERBAGAI UMUR PANEN

This study aims to find out the results of cassava tuber crop UJ5 variety at different harvest ages. Research direction is that cassava varieties have been planted throughout Indonesia as the best producer of cassava varieties. High levels of starch and high HCN content makes this variety was selected by the factory - tapioca factory in Indonesia. Research design used randomized block design with 7 treatments of harvesting (UP) were repeated 3 times. UP6 (harvesting 6 MAP), UP7 (harvesting 7 MAP), UP8 (harvesting 8 MAP), UP9 (harvesting 9 MAP), UP10 (harvesting 10 MAP), UP11 (harvesting 11 MAP), UP12 ( harvesting 12 MAP). The research variables are the fresh weight of tuber, tuber starch content (%), the weight of biomass, harvest index, number of tubers per plant. The results showed that the best harvesting time is UP9 the results did not differ with UP10, UP11 and UP12

UJI DAYA HASIL UBIKAYU (Manihot esculenta Crantz) VARIETAS UJ5 PADA BERBAGAI UMUR PANEN

This study aims to find out the results of cassava tuber crop UJ5 variety at different harvest ages. Research direction is that cassava varieties have been planted throughout Indonesia as the best producer of cassava varieties. High levels of starch and high HCN content makes this variety was selected by the factory - tapioca factory in Indonesia. Research design used randomized block design with 7 treatments of harvesting (UP) were repeated 3 times. UP6 (harvesting 6 MAP), UP7 (harvesting 7 MAP), UP8 (harvesting 8 MAP), UP9 (harvesting 9 MAP), UP10 (harvesting 10 MAP), UP11 (harvesting 11 MAP), UP12 ( harvesting 12 MAP). The research variables are the fresh weight of tuber, tuber starch content (%), the weight of biomass, harvest index, number of tubers per plant. The results showed that the best harvesting time is UP9 the results did not differ with UP10, UP11 and UP12

Tuber Quality Parameters of Potato Varieties Depend on Potassium Fertilizer Rate and Source

Abstract The influence of potassium fertilizer source (K 2 SO 4 and KCl) and fertilizer rates on potato tuber quality parameters under pot and field experimental conditions were studied. The pot experiment included high rate of potassium fertilizers providing 600 mg K 2 O kg -1 soil from both sources, studded at four varieties. The field experiment included two fertilizer rates - 100 and 200 kg K 2 O ha -1 . The dry matter content in tubers from the plants of the pot experiment was the highest for the controls of the three studied varieties - 19.78% for „Louisiana”; 17.16 for „Riviera” and 17.26% for „Hussar”. The highest dry matter content (20.98%) in field conditions was observed for variant K 200 (K 2 SO 4 ). For all variants from the pot trail fertilized with KCl the starch content was decreased approximately with 2.2 to 2.4% in comparison to controls. The highest tuber starch content was observed also for the control (15.24%) from the field study. The fertilization did not influence the reducing sugars content in tubers. The content was around 0.40% independently of the trail conditions and cultivars. The application of KCl decreased the content of vitamin C in tubers for all variants from the pot trail compared to the controls (from 46% at variety „Louisiana” to 61% to Agria). In the field experiment the high rate of K 200 KCl reduced vitamin C content with approximately 54% (8.40 mg 100 g -1 ) in comparison to variant K 100 K 2 SO 4 (18.10 mg 100 g -1 ). Positive influence of KCl on crude protein content in tubers at all varieties from both trials was recorded.

КАЧЕСТВО УРОЖАЯ СЕЛЬСКОХОЗЯЙСТВЕННЫХ КУЛЬТУР НА ЕВРОПЕЙСКОЙ ТЕРРИТОРИИ РФ В УСЛОВИЯХ ИЗМЕНЕНИЯ КЛИМАТА

The positive trend of starch content in potato tubers under the conditions of Murmansk Province and sugar content in grapes under the conditions of Rostov Province is shown for the period of the 1990s. Weather dependence of protein content in wheat was investigated in the experiments of 1963-1993 at four experimental stations of the Vavilov Institute. Direct dependence of the studied quality indicators on the sum of temperatures above 15°C and inverse dependence on the sum of rainfall for this period have been identified.

Mapping of quantitative trait loci for tuber starch and leaf sucrose contents in diploid potato

Key messageMost QTL for leaf sucrose content map to positions that are similar to positions of QTL for tuber starch content in diploid potato.In the present study, using a diploid potato mapping population and Diversity Array Technology (DArT) markers, we identified twelve quantitative trait loci (QTL) for tuber starch content on seven potato chromosomes: I, II, III, VIII, X, XI, and XII. The most important QTL spanned a wide region of chromosome I (42.0–104.6 cM) with peaks at 63 and 84 cM which explained 17.6 and 19.2 % of the phenotypic variation, respectively. ADP-glucose pyrophosphorylase (AGPase) is the key enzyme for starch biosynthesis. The gene encoding the large subunit of this enzyme, AGPaseS-a, was localized to chromosome I at 102.3 cM and accounted for 15.2 % of the variance in tuber starch content. A more than 100-fold higher expression of this gene was observed in RT-qPCR assay in plants with the marker allele AGPaseS-a1334. This study is the first to report QTL for sucrose content in potato leaves. QTL for sucrose content in leaves were located on eight potato chromosomes: I, II, III, V, VIII, IX, X and XII. In 5-week-old plants, only one QTL for leaf sucrose content was detected after 8 h of darkness; four QTL were detected after 8 h of illumination. In 11-week-old plants, 6 and 3 QTL were identified after dark and light phases, respectively. Of fourteen QTL for leaf sucrose content, eleven mapped to positions that were similar to QTL for tuber starch content. These results provide genetic information for further research examining the relationships between metabolic carbon molecule sources and sinks in potato plants.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-015-2615-9) contains supplementary material, which is available to authorized users.