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Copyright of Acta Agriculturae Slovenica is the property of Biotechnical Faculty of the University of Ljubljana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Worldwide, potato (Solanum tuberosum L.) is one of the most essential agro-economically food crops. To ensure its presence throughout the year for food processors and to extend its shelf life, it should be stored in cold temperatures. Despite the benefits of storage at low temperatures, it causes undesirable phenomena; one of them is cold-induced sweetening, which reduces the quality and the commercial value of the potato tubers. In this study, the CRISPR technology ″Clustered Regularly Interspaced Short Palindromic Repeats″ has been used in potato cultivar Desiree via Agrobacterium-mediatied transformation to edit starch phosphorylase gene that is responsible for starch degradation in cold temperature storage, after regeneration steps. The regenerated plants were used in the screening of genome editing by Sanger sequencing and the ICE program. Screening results showed that Desiree 2 (DE2), Desiree 7 (DE7) and Desiree 27 (DE27) lines have mutations in sgRNA sequence that indicated a significant reduction in reduced sugar contents of tubers after cold storage for 90 and 120 days. The reduction mean values were 29.224, 35.078 and 35.862 in DE2, DE7 and DE27 respectively after 90 days and 83.212, 56.674 and 34.109 after 120 days without visible differences in plant morphology and tubers. [ABSTRACT FROM AUTHOR]

The article titled "In vitro Propagation and Genetic Assessment by using Markers in Potato (Solanum tuberosum L.) cv Kufri Ganga" discusses a study on the micropropagation of potato plants and the genetic assessment of tissue culture raised plants. The researchers found that a combination of growth regulators resulted in the highest number of shoots per explant, and different potting mixtures influenced the survival percentage of the plants. Genetic fidelity testing confirmed the genetic stability of the tissue culture raised plants. This study provides an efficient method for potato plant propagation and highlights the importance of genetic stability in tissue culture-derived plants. Another article discusses the in vitro propagation of Lysimachia davurica, a medicinal and ornamental plant. The study explores the best methods for propagating this plant in a laboratory setting, including the type of growth medium and hormone treatments. This research is valuable for individuals interested in cultivating Lysimachia davurica for medicinal or ornamental purposes. [Extracted from the article]

Inorganic phosphate (Pi) is one of the main nutrients necessary for plant growth. Phosphate transporters mediate the acquisition, transport and recycling of phosphate, which is essential for plant growth and development. Although PHT1 has been reported in many plants at home and abroad, it is rarely studied in potato. Therefore, it is of great significance to study the PHT1 family members in order to understand the molecular response mechanism of potato in low phosphate state. In this study, a total of 6 potato PHT1 genes were identified and isolated. It was found that after the expression of different members of potato PHT1 gene, there were certain differences in amino acids and proteins, and the transmembrane domains ranged from 6 to 12. The difference in the secondary and tertiary protein structure of potato PHT1 also led to a difference in protein morphology. In addition, the expression of the PHT1 gene in potato increased obviously during 3~9 h of Pi deficiency stress. Overall, the expression levels of different genes in roots, stems and leaves are distinctly different, but the expression levels of the StPHT1;6 and StPHT1;10 genes are very high in roots, stems and leaves, indicating that these two genes may participate in the absorption of Pi in potato and play a role in Pi translocation. These two genes play a major role in the regulation of expression under short-term Pi deficiency stress. Our results provide an important reference for further understanding the evolution and function of potato phosphate transporters, and have important significance for improving the ability of potato to tolerate low Pi. [ABSTRACT FROM AUTHOR]

Fifty-two potato (Solanum tuberosum L.) genotypes were evaluated in early crop season (75 days) at experimental field of ICAR-Central Potato Research Institute, Regional Station, Modipuram, Meerut, Uttar Pradesh, during 2020 and 2021. Significant differences were recorded among for tuber yield and tuber attributes like plant vigour (1-5 scale), foliage maturity (1-5 scale), tuber colour, tuber shape, eye depth and flash colour. The pooled results of 2020 and 2021 crop seasons indicated that eight genotypes namely Kufri Mohan (260 g), Kufri Lima (256 g), CP4149 (252g), Kufri Garima (241g), Kufri Bahar (239 g), CP3273 (236 g), Kufri Neelkanth (221 g), CP4143 (212 g), CP1326 (208 g) and Kufri Arun (207 g), were found high-yielding in term of total tuber yield/plant. The highest marketable tuber yield/plant was recorded in Kufri Lima (234g), CP4149 (230 g), Kufri Mohan (225 g), CP3273 (213 g), Kufri Bahar (211 g), Kufri Garima (208 g), CP4143 (190 g), Kufri Neelkanth (182 g), Atlantic (178 g) and Kufri Arun (177 g). The genotypes, CP1931, CP3319, CP3322, CP3450, CP3470, CP3499, CP4149, CP4238, Kufri Garima, Kufri Lima, Kufri Surya and Lady Rossetta, were found highly tolerant with 0% hopper burn incidence. Most of the genotypes were highly tolerant with 0% mite damage incidence except CP3495, CP3341and CP3472 (20%) and Kufri Sindhuri and Kufri Pukhraj (40%). On an overall basis CP4149, Kufri Mohan, Kufri Garima and Kufri Lima were found promising for high plant stand, plant vigour, marketable/total tuber yield, marketable/total tuber number and nil/low incidence of hopper and mite burn. [ABSTRACT FROM AUTHOR]

This study was carried out in 2018 to examine the yield and yield components of 8 potato genotypes (Kanursu, Aşkar, Çamlı, Akbulut, Yukarıkızı, Incili, Erikdibi, and Nisantası) and 2 potato varieties (Agria and Lady Olympia) procured in the ecological conditions of Bayburt, Turkey. The experimental work was conducted in trial ground at the Experimental Station of the University of Bayburt (Turkey). The research was designed in random blocks with three replications. As a result of the study, the highest number of stems per plant (6.7), tuber yield per hectare (15.19 tons), number of tubers per plant (8.47), and tuber yield per plant (357.01 g) were found to be in the genotype Akbulut; the highest ratio of large tuber (28.27%) in the genotype Konursu; and the highest ratio of medium tuber (85.22%) in the genotype Çamlıkoz. This study; Although the best potato yield was obtained from the Akbulut genotype on a regional basis, these data are a pioneer for other future studies to determine the cultivar candidates needed in the development of domestic potato cultivars. [ABSTRACT FROM AUTHOR]

This study aimed to determine the potato breeding lines that show superior processing quality traits and can be candidate variety by selection. The study was conducted according to The Randomized Plots Trial Design with four replications in 2019 and 2020. In the study, 26 potato breeding lines developed by Selcuk University, Faculty of Agriculture, Department of Field Crops, and 4 registered varieties as plant material were used in the two years. The varieties and lines were harvested in the fields and then the genotypes were evaluated according to processing quality traits. In the study; dry matter ratio (%), chips yield (%), French fries yield (%), chips, and French fries color (L*, b*) parameters were examined. Dry matter ratio, chips yield and French fries yield, and chips and French fries color values were found important statistically in terms of years, genotypes, year x genotype interactions. Values of chips and French fries color were varied from only genotypes averages. According to two years average, results showed large variations for examined parameters; dry matter ratio changed between 16.8-20.9 %, chips yield was 34.1-51.0 %, French fries yield was 30.7-44.9 %, chips color values (L*, b*) were 19.4-67.1, 8-44 and French fries color values (L*, b*) were 11.4-71.5, 13.5-58.2, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Agronomía Colombiana is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of study was to assess the genetic diversity of potato varieties of different maturity groups by SSR markers. Twenty-four potato varieties of different maturity groups (very early, yearly, medium, late) were investigated by 8 SSR markers (STM0019, STM3009, STM2005, STM2028, STM3012, STM3023, STM5136, STM5148) for genetic diversity assessment. To assess the genetic diversity of studied varieties, the cluster analysis was performed and the genetic distances between varieties were determined. As results of PCR analysis from 6 to 10 alleles were determined with an average of 7.88 alleles. The most polymorphic marker was STM2028 with PIC 0.89. The lowest value of PIC (0.78) was obtained for STM3012 marker. For other studied markers values of PIC were from 0.82 to 0.88. It was found, that the most similar varieties are varieties with genetic distance 3.74: Pravda and Riviera, Pravda and Vzirets. The most different varieties turned out to be Vzirets and Lilly, ESMEE and Opilla varieties with genetic distance 6.00. Thus, it was found that the major of studied varieties formed cluster grouts according their maturity groups. [ABSTRACT FROM AUTHOR]

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

Crop production is threatened by low phosphorus (P) availability and weed interference. Obtaining plant genotypes that can utilize Phosphite (Phi) as fertilizer can supplement phosphates (Pi) while providing an environmentally friendly means of weed control. The study was conducted to determine the tolerance and enzymatic behavior of five potato genotypes to PO3. Explants were regenerated in vitro from two nodal cuttings and cultured on Murashige and Skoog (MS) medium under controlled conditions for 30 days. Matured plantlets were subcultured for 20 days in MS medium containing (0.25, 0.5 mM) Phi and Pi and No-P (-Phi + -Pi). The results showed significant genotypic variation in tolerance indices among the five genotypes. Atlantic showed greater tolerance to Phi, with highest total root length (50.84%), root projected area (75.09%), root surface area (68.94%), root volume (33.49%) and number of root forks (75.66%). Phi induced an increasing trend in the levels of hydrogen peroxide in the genotypes with the least effect in Atlantic. The comprehensive evaluation analysis confirmed the tolerance of Atlantic genotype with this ranking; Atlantic, Longshu3, Qingshu9, Longshu6 and Gannong2. Antioxidant enzyme activities and proline content also increased significantly under Phi and No-P treatments. The results suggested that potato genotypes with larger root systems may be more tolerant to Phi than genotypes with smaller root systems. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural, Environmental & Veterinary Sciences is the property of Arab Journal of Sciences & Research Publishing (AJSRP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Knowledge regarding genetic diversity and population structure of breeding materials is essential for crop improvement. The Texas A&M University Potato Breeding Program has a collection of advanced clones selected and maintained in-vitro over a 40-year period. Little is known about its genetic makeup and usefulness for the current breeding program. In this study, 214 potato clones were genotyped with the Infinium Illumina 22 K V3 Potato Array. After filtering, a total of 10,106 single nucleotide polymorphic (SNP) markers were used for analysis. Heterozygosity varied by SNP, with an overall average of 0.59. Three groups of tetraploid clones primarily based on potato market classes, were detected using STRUCTURE software and confirmed by discriminant analysis of principal components. The highest coefficient of differentiation observed between the groups was 0.14. Signatures of selection were uncovered in genes controlling potato flesh and skin color, length of plant cycle and tuberization, and carbohydrate metabolism. A core set of 43 clones was obtained using Core Hunter 3 to develop a sub-collection that retains similar genetic diversity as the whole population, minimize redundancies, and facilitates long-term conservation of genetic resources. The comprehensive molecular characterization of our breeding clone bank collection contributes to understanding the genetic diversity of existing potato resources. This analysis could be applied to other breeding programs and assist in the selection of parents, fingerprinting, protection, and management of the breeding collections. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural, Environmental & Veterinary Sciences is the property of Arab Journal of Sciences & Research Publishing (AJSRP) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the past, the potato plant microbiota and rhizosphere have been studied in detail to improve plant growth and fitness. However, less is known about the postharvest potato tuber microbiome and its role in storage stability. The storage stability of potatoes depends on genotype and storage conditions, but the soil in which tubers were grown could also play a role. To understand the ecology and functional role of the postharvest potato microbiota, we planted four potato varieties in five soil types and monitored them until the tubers started sprouting. During storage, the bacterial community of tubers was analysed by next-generation sequencing of the 16S rRNA gene amplicons. The potato tubers exhibited soil-dependent differences in sprouting behaviour. The statistical analysis revealed a strong shift of the tuber-associated bacterial community from harvest to dormancy break. By combining indicator species analysis and a correlation matrix, we predicted associations between members of the bacterial community and tuber sprouting behaviour. Based on this, we identified Flavobacterium sp. isolates, which were able to influence sprouting behaviour by inhibiting potato bud outgrowth. [ABSTRACT FROM AUTHOR]

Copyright of Agronomía Colombiana is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Potato multiplication with seeds reduces the costs of agriculture, environmental damage resulting from the use of pesticides to maintain seeds and helps to produce seeds resistant to viral diseases. However, low seed germination rate of some varieties can considerably limit the production of potatoes in this way. The aim of this study was to evaluate the effect of soaking seeds of six potato strain in different concentrations of gibberellin on germination rate and characters of yielded mini-tubers. Potato seeds of all strain (imported ID, MST186-1Y, MSL211, MSV093-1 and MSS927-01 and the local comparison cultivar Burren) were soaked in gibberellin at three concentration levels (0, 500 or 1000 mg/L). The seeds were then dried and planted in cork dishes inside the greenhouse. At stage of two true leafs, the seedlings were transferred to 4 kg pots containing field soil and peat moss at 3:1 ratio. Pots were distributed based on RCBD with four replicates and five pots per experimental unit. The results of the study showed that the treatment of potato seeds with gibberellin had a significant effect in increasing the rate and speed of germination and the number and weight of tubers produced. In general, the highest concentration of gibberellin (1000 mg / L) was more effective than the lowest concentration and significantly differed from the distilled water treatment. All the values of the studied traits were affected by plant cultivar. The ID cultivar recorded highest values in germination ratio, number and weight of tubers. The strain did not differ in germination speed although MSL211 gave the highest rate of germination speed among all treatments and with only significant difference from the lowest rate recorded in the comparison cultivar Borin. Interaction of gibberellin treatment and potato cultivar was always effective in increasing all the tested traits over the untreated control. Findings of this study showed successful production of potato mini-tubers from potato seeds in case of Iraqi field conditions. [ABSTRACT FROM AUTHOR]

Chipping potatoes are bred for their ability to produce light-colored, defect-free chips. Chips with stem-end chip defect (SECD) have dark blemishes and are undesirable to consumers and chip processors. The heritability of SECD is not known and genetic loci linked to defect formation have not been identified. Chip processing varieties 'Wauseon' and 'Lenape' were crossed and tubers from parents and 191 progeny were evaluated over four years for chip color descriptors L*, a*, and b* and SECD score in January, March, and May. Broad sense heritability for SECD was 0.64 or greater at each sampling time. Genotype data were used to construct a 1282 cM linkage map. Nine quantitative trait loci (QTL) for SECD were detected, and seven overlapped QTL for chip color traits. The QTL identified are starting points for developing molecular markers that are used to select genotypes that produce light-colored chips and have resistance to SECD formation. [ABSTRACT FROM AUTHOR]

Summary: Interploidal hybridisation can generate changes in plant chromosome numbers, which might exert effects additional to the expected due to genome merger per se (that is genetic, epigenetic and phenotypic novelties).Wild potatoes are suitable to address this question in an evolutionary context. To this end, we performed genetic (AFLP and single sequence repeart (SSR)), epigenetic (MSAP), and cytological comparisons in: (1) natural populations of the diploid cytotype of the hybrid taxonomic species Solanum × rechei (2n = 2×, 3×) and its parental species, the triploid cytotype of Solanum microdontum (2n = 2×, 3×) and Solanum kurtzianum (2n = 2×); and (2) newly synthesised intraploidal (2× × 2×) and interploidal (3× × 2×) S. microdontum × S. kurtzianum hybrids.Aneuploidy was detected in S. × rechei and the synthetic interploidal progeny; this phenomenon might have originated the significantly higher number of methylation changes observed in the interploidal vs the intraploidal hybrids. The wide epigenetic variability induced by interploidal hybridisation is consistent with the novel epigenetic pattern established in S. × rechei compared to its parental species in nature.These results suggest that aneuploid potato lineages can persist throughout the short term, and possibly medium term, and that differences in parental ploidy resulting in aneuploidy are an additional source of epigenetic variation. [ABSTRACT FROM AUTHOR]

Highlights • Nitrogen fertilizer significantly decreased potato foliar total sugar concentration, which is a stimulant for CPB feeding. • High N rate increased potato foliar concentrations of glycoalkaloids, which are toxic to CPB. • High N fertilizer rates increased marketable tuber yield and N accumulation of potato plants. • Maximum marketable yield, lower sugar and higher glycoalkaloid concentrations were achieved at the N rate of 205 kg N ha−1. Abstract The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is a destructive pest of potato (Solanum tuberosum L.) crops. Leaf sugars are regarded as energy sources for the growth of the CPB, while glycoalkaloids are used to suppress the feeding behaviors of the CPB. The metabolic pathway of these leaf compounds is closely related to nitrogen (N) nutrition. Additionally, N plays an important role in determining tuber yield. The objective of this study was to investigate the effects of N fertilization on the concentrations of sugars and glycoalkaloids in potato leaves and on marketable tuber yield under field conditions in eastern Canada. Experiments were conducted at three sites and five N rates (0, 60, 120, 180, and 240 kg N ha−1) provided in a randomized complete block design. The potato cultivar "Russet Burbank" was used throughout the experiments. Twenty potato plants were randomly selected in each plot and the fourth leaf from the top of each plant was collected at 40, 54, 68, and 82 days after planting (DAP) for analyzing the concentrations of sugars (sucrose, glucose, and fructose) and glycoalkaloids (α-solanine and α-chaconine). Marketable tuber yield was determined along with the whole plant (vine + tuber) N accumulation. A significant decline of the averaged total sugar, including sucrose and glucose, was observed with increasing N rates. The average concentration of total glycoalkaloid, including α-chaconine, increased significantly in response to the increasing N rates. Based on our results, a rate of 205 kg N ha-1 was identified to obtain a maximum marketable tuber yield along with high concentrations of glycoalkaloid and low sugar concentrations which may influence the CPB feeding. [ABSTRACT FROM AUTHOR]

Summary: Following the molecular characterisation of functional disease resistance genes in recent years, methods to track and verify the integrity of multiple genes in varieties are needed for crop improvement through resistance stacking. Diagnostic resistance gene enrichment sequencing (dRenSeq) enables the high‐confidence identification and complete sequence validation of known functional resistance genes in crops. As demonstrated for tetraploid potato varieties, the methodology is more robust and cost‐effective in monitoring resistances than whole‐genome sequencing and can be used to appraise (trans) gene integrity efficiently. All currently known NB‐LRRs effective against viruses, nematodes and the late blight pathogen Phytophthora infestans can be tracked with dRenSeq in potato and hitherto unknown polymorphisms have been identified. The methodology provides a means to improve the speed and efficiency of future disease resistance breeding in crops by directing parental and progeny selection towards effective combinations of resistance genes. [ABSTRACT FROM AUTHOR]

Graphical abstract The expression profiles of StTCP genes in different tissues. The StTCP genes transcript abundance were detected by RNA-Seq technology and expressed by FPKM values, and the color scale represents relative expression levels, red as higher expression levels and green as lower expression levels. Highlights • 31 TCP transcription factors were identified in potato. • All StTCPs could take part in transcriptional regulation and had DNA binding ability. • 7 StTCP genes were dramatically up-regulated during the release of tuber dormancy. • Some StTCP genes obviously responded to different abiotic stresses and multiple hormones. Abstract The plant-specific TCP transcription factors, which play critical roles in diverse aspects of biological processes, have been identified and analyzed in various plant species. However, no systematical study of TCP family genes in potato (Solanum tuberosum L.) has been undertaken. In this study, a total of 31 non-redundant TCP transcription factors of potato were identified and divided into two subfamilies including three distinct subclades. The various orthologous TCP genes in Arabidopsis , rice, potato and tomato were identified using synteny and phylogenetic analysis. Protein motif analysis demonstrated that StTCPs in the same subclade shared similar conserved motif structures. Gene structure analysis showed that almost all StTCPs displayed highly conserved exon-intron organization. The analysis of StTCP gene promoter regions revealed that multiple cis -acting elements were involved in plant growth, development, hormone responses as well as stress responses. The result of StTCP gene expression profiles showed they had tissue-specific expression patterns which implied their differentiated functions. According to the results of quantitative RT-PCR (qRT-PCR), 7 StTCP genes were dramatically up-regulated during the release of tuber dormancy and some specific StTCP genes were strongly responding to different abiotic stresses and multiple hormones, which suggested they had important roles in potato growth and development processes. The results of our findings could provide comprehensive insights in StTCP family genes of potato for further functional investigations. [ABSTRACT FROM AUTHOR]

The National Chip Processing Trial is a collaborative effort between public breeding programs and the potato (Solanum tuberosum L.) industry to identify new clones with broad adaptation. The objective of this study was to investigate the genetic covariance of trial locations, based on 337 clones evaluated in 10 states from 2011 to 2016. Three models were considered: (I) assuming a uniform genetic correlation between locations within a year, (II) using a factor-analytic (FA) model of the total genetic covariance of environments (location--year combinations), and (III) using a FA model of the additive genetic covariance based on 5278 single-nucleotide polymorphism (SNP) markers. With Model I, the genetic correlation between locations was 0.50 for vine maturity, 0.54 for tuber yield, and 0.72 for specific gravity. The Akaike information criterion decreased as model complexity increased, from Models I to II to III, for maturity and yield but not specific gravity. Of the 10 states in the dataset, Florida stood out for having environments with substantial (up to 88%) genetic variance unexplained by the latent factors. Linear discriminants (LD) of the factor loadings were used to visualize the genetic correlation between locations. For vine maturity, LD1 separated Florida from the other locations, and LD2 separated the remaining southern locations from the northern ones. For yield, LD1 separated Texas from the other locations. This study has created a foundation for the design of more efficient trialing and selection programs for the US potato community. [ABSTRACT FROM AUTHOR]

The in vitro effect of growth regulators under cool white fluorescent light (for 16 h at 50 μmol. m-2 s-1) and dark conditions to accelerate microtuberization in potato cvs. Desiree and Cardinal were investigated. The axillary buds were selected as an explant, inoculated on MS medium augmented with and without growth regulators (BAP (6-Benzylaminopurine) and NAA (a-Naphthaleneacetic acid) to initiate microtuberization. Combination of growth regulators (NAA + BAP) in media produces callus or had no effect on culture. NAA in any concentration, alone or in combination with BAP promote callus formation only. BAP alone in low concentration (0.5 mg/l) proliferate shoot regeneration and while at high (1.0 mg/l) concentration it induces microtuberization in the dark by 63 percent of control. It was found that nutrient media, without growth regulator had higher yield and greater number of microtubers under both light (16 h) and dark conditions as compared to those cultured on media with growth regulator. However, study revealed that MS0 medium with vitamins and solidified agar free of growth regulators can be utilized for mass propagation and microtuberization under the optimized culture conditions. [ABSTRACT FROM AUTHOR]

Abstract Water rots are a group of important potato tuber rot diseases such as pink rot, Phytophthora tuber rot, and leak caused by the oomycete pathogens Phytophthora erythroseptica , P. nicotianae, and Pythium ultimum , respectively. If not managed, these diseases either alone or in combination, can cause severe yield loss and substantial reductions in quality. Growers continue to rely on fungicides for water rot management in the field and during post-harvest storage. Previous and ongoing breeding attempts have failed to identify and develop commercially acceptable potato cultivars resistant to all three diseases. This is mainly due to the complex, expensive, and time-consuming methodologies required to screen for susceptibility to water rot pathogens. Currently, potato genotypes are assessed for susceptibility to individual water rot pathogens which is labor intensive. Considerable savings in time and effort would be realized if potato genotypes could be evaluated for susceptibility to one water rot pathogen and then statistical analysis applied to determine the probability of the reaction of a genotype to the other rot pathogens. A proportional odds model was fitted to examine the risk of genotype screening outcome (ordinal) to understand the relationships among water rot causing oomycetes in potato. Compared to P. erythroseptica , P. ultimum infected genotypes having susceptibility risk was high (2.6) versus other cultivar susceptibility categories. Potato genotypes screened for P. nicotianae have a significant susceptibility risk decreased by 38% when compared to P. erythroseptica. Highlights • Proportion odds model is used to model ordinal outcome. • Risk of potato genotype screening outcome was used to understand the relationship between water rot pathogens. • Compared to Phytophthora erythroseptica , Pythium ultimum infected genotypes have high susceptibility risk. [ABSTRACT FROM AUTHOR]

Anthocyanins are plant pigments responsible for the colors of many flowers, fruits and storage organs and have roles in abiotic and biotic stress resistance. Anthocyanins and polyphenols are bioactive compounds in plants including potato (Solanum tuberosum L.) which is the most important non-cereal crop in the world, cultivated for its tubers rich in starch and nutrients. The genetic regulation of the flavonoid biosynthetic pathway is relatively well known leading to the formation of anthocyanins. However, our knowledge of post-transcriptional regulation of anthocyanin biosynthesis is limited. There is increasing evidence that micro RNAs (miRNAs) and other small RNAs can regulate the expression level of key factors in anthocyanin production. In this study we have found strong associations between the high levels of miR828, TAS4 D4(-) and purple/red color of tuber skin and flesh. This was confirmed not only in different cultivars but in pigmented and non-pigmented sectors of the same tuber. Phytochemical analyses verified the levels of anthocyanins and polyphenols in different tissues. We showed that miR828 is able to direct cleavage of the RNA originating from Trans-acting siRNA gene 4 (TAS4) and initiate the production of phased small interfering RNAs (siRNAs) whose production depends on RNA-dependent RNA polymerase 6 (RDR6). MYB transcription factors were predicted as potential targets of miR828 and TAS4 D4(-) and their expression was characterized. MYB12 and R2R3-MYB genes showed decreased expression levels in purple skin and flesh in contrast with high levels of small RNAs in the same tissues. Moreover, we confirmed that R2R3-MYB and MYB-36284 are direct targets of the small RNAs. Overall, this study sheds light on the small RNA directed anthocyanin regulation in potato, which is an important member of the Solanaceae family. [ABSTRACT FROM AUTHOR]

Clustered regularly interspaced short palindromic repeats and CRISPR‐associated protein‐9 (CRISPR‐Cas9) can be used as an efficient tool for genome editing in potato (Solanum tuberosum). From both a scientific and a regulatory perspective, it is beneficial if integration of DNA in the potato genome is avoided. We have implemented a DNA‐free genome editing method, using delivery of CRISPR‐Cas9 ribonucleoproteins (RNPs) to potato protoplasts, by targeting the gene encoding a granule bound starch synthase (GBSS, EC 2.4.1.242). The RNP method was directly implemented using previously developed protoplast isolation, transfection and regeneration protocols without further adjustments. Cas9 protein was preassembled with RNA produced either synthetically or by in vitro transcription. RNP with synthetically produced RNA (cr‐RNP) induced mutations, i.e. indels, at a frequency of up to 9%, with all mutated lines being transgene‐free. A mutagenesis frequency of 25% of all regenerated shoots was found when using RNP with in vitro transcriptionally produced RNA (IVT–RNP). However, more than 80% of the shoots with confirmed mutations had unintended inserts in the cut site, which was in the same range as when using DNA delivery. The inserts originated both from DNA template remnants from the in vitro transcription, and from chromosomal potato DNA. In 2–3% of the regenerated shoots from the RNP‐experiments, mutations were induced in all four alleles resulting in a complete knockout of the GBSS enzyme function. [ABSTRACT FROM AUTHOR]

The experiment was conducted in Randomized Block Design (RBD) with three replications in two sets of harvest period i.e. 90 and 105 days after planting (DAP) for tuber yield and processing traits in potato. The analysis of variance revealed that mean sum of squares due to genotypes was found highly significant for all the traits under study. The genotypes of MS/06-1947, K. Sadabahar and K. Khyati for 90 days and J/10-162, K. Sadabahar and MP/06-39 for 105 DAP were found promising for tuber yield per plant based on per se performance. The genotypes of MP/09- 901, MP/04-578 and MP/04-816 exhibited high tuber dry matter, while, the genotypes, K. Himsona, K.Chipsona 1 and K.Chipsona 2 had low reducing sugar under both 90 and 105 days of harvest. The low chip colour index was exerted by genotypes of K. Chipsona 2, K. Chipsona 1, K. Chipsona 3, K. Chipsona 4 and K. Frysona under 90 days, whereas, K. Chipsona 2, Atlantic and K. Chipsona 3 under 105 days of harvest. Therefore, these genotypes suited as processing purpose. The high heritability along with high genetic advance in leaf area, number of stems per hill, number of tubers per plant, processing grade tuber yield per plant, chip colour index, reducing sugar and total soluble solids under both harvesting periods, recommended that genotypic difference for the characters ascribed to high additive genetic cause and selection would be wrathful based on phenotypic performance. [ABSTRACT FROM AUTHOR]

Plant STRUBBELIG (SUB)-RECEPTOR FAMILY (SRF) genes encode putative leucine-rich repeat transmembrane receptor-like kinases. SRFs have been reported to play essential roles in tissue morphogenesis in many plant organs. Here, we show that a potato SRF family gene, StLRPK1, is involved in plant immunity. StLRPK1 is located at the cell plasma membrane and is strongly induced by culture filtrate from in vitro growth of the late blight pathogen Phytophthora infestans. Overexpression of StLRPK1 in stable transgenic potato or ectopic expression in Nicotiana benthamiana plants enhances P. infestans disease resistance, whereas RNA interference (RNAi) of StLRPK1 in potato decreases disease resistance. We found that StLRPK1 constitutively interacts with a pivotal co-receptor, SERK3A/BAK1, which plays a central role in plant immunity. Virus-induced gene silencing of SERK3A/BAK1 in N. benthamiana lines expressing StLRPK1 attenuated P. infestans resistance, indicating that SERK3A/BAK1 is required for StLRPK1 -mediated immunity. Finally, we show that StLRPK1-triggered late blight resistance depends on the mitogen-activated protein kinase kinase MEK2 and mitogen-activated protein kinase WIPK. We propose a model in which StLRPK1 associates with SERK3A/BAK1 to positively regulate plant immunity to P. infestans through a MAPK cascade. These data provide new insights into our understanding of SRF function in plant immunity. [ABSTRACT FROM AUTHOR]

Crop genetic engineering involves transformation in which transgenic plants are regenerated through tissue culture manipulations that can elicit somaclonal variation due to mutations, translocations, and/or epigenetic alterations. Here, we report on alterations in the transcriptome in a panel of transgenic potato plants engineered to be herbicide resistant. Using an inbred diploid potato clone (DMRH S5 28–5), ten single-insert transgenic lines derived from independent Agrobacterium-mediated transformation events were selected for herbicide resistance using an allelic variant of acetolactate synthase (mALS1). Expression abundances of the single-copy mALS1 transgene varied in individual transgenic lines was correlated with the level of phenotypic herbicide resistance, suggesting the importance of transgene expression in transgenic performance. Using RNA-sequencing, differentially expressed genes were identified with the proportion of genes up-regulated significantly higher than down-regulated genes in the panel, suggesting a differential impact of the plant transformation on gene expression activation compared to repression. Not only were transcription factors among the differentially expressed genes but specific transcription factor binding sites were also enriched in promoter regions of differentially expressed genes in transgenic lines, linking transcriptomic variation with specific transcription factor activity. Collectively, these results provide an improved understanding of transcriptomic variability caused by plant transformation. [ABSTRACT FROM AUTHOR]

Abstract: Key message Sen2gene for potato wart resistance, located on chromosome XI in a locus distinct fromSen1, provides resistance against eight wart pathotypes, including the virulent ones important in Europe.Abstract: Synchytrium endobioticum causes potato wart disease imposing severe losses in potato production, and as a quarantine pathogen in many countries, it results in lost trade markets and land for potato cultivation. The resistance to S. endobioticum pathotype 1(D1) is widespread in potato cultivars but new virulent pathotypes appear and the problem re-emerges. To characterize and map a new gene for resistance to potato wart, we used diploid F1 potato population from a cross of potato clone resistant to S. endobioticum pathotype 1(D1) and virulent pathotypes: 2(G1), 6(O1), 8(F1), 18(T1), 2(Ch1), 3(M1) and 39(P1) with a potato clone resistant to pathotype 1(D1) only. The 176 progeny clones were tested for resistance to eight wart pathotypes with a modified Glynne-Lemmerzahl method. Bimodal distributions and co-segregation of resistance in the population show that a single resistance gene, Sen2, underlies the resistance to eight pathotypes. Resistance to pathotype 1(D1) was additionally conferred by the locus Sen1 inherited from both parents. Sen2 was mapped to chromosome XI using DArTseq markers. The genetic and physical distances between Sen1 and Sen2 loci were indirectly estimated at 63 cM and 32 Mbp, respectively. We developed PCR markers co-segregating with the Sen2 locus that can be applied in marker-assisted selection of potatoes resistant to eight important pathotypes of S. endobioticum. Wide spectrum of the Sen2 resistance may be an indication of durability which can be enhanced by the pyramiding of the Sen2 and Sen1 loci as in 61 clones selected within this study. [ABSTRACT FROM AUTHOR]

Physiology and genetics are tightly interrelated. Understanding the genetic basis of a physiological trait such as the quantum yield of the photosystem II, or photosynthetic responses to environmental changes will benefit the understanding of these processes. By means of chlorophyll fluorescence (CF) imaging, the quantum yield of photosystem II can be determined rapidly, precisely and non‐invasively. In this article, the genetic control and variation in the steady‐state quantum yield of PSII (ΦPSII) is analyzed for diploid potato plants. Current progress in potato research and breeding is slow due to high levels of heterozygosity and complexity of tetraploid genetics. Diploid potatoes offer the possibility of overcoming this problem and advance research for one of the globally most important staple foods. With the help of a diploid genetic mapping population two genetic loci that were strongly associated with differences in ΦPSII were identified. This is a proof of principle that genetic analysis for ΦPSII can be done on potato. The effects of three different stress conditions that are important in potato cultivation were also tested: salt stress, low temperature and deficiency in the macronutrient phosphate. For the last two stresses, significant decreases in photosynthetic activity could be shown, revealing potential for stress detection with CF based tools. In general, our findings show the potential of high‐throughput phenotyping for physiological research and breeding in potato. [ABSTRACT FROM AUTHOR]

Background: MADS-box genes encode transcription factors that are known to be involved in several aspects of plant growth and development, especially in floral organ specification. To date, the comprehensive analysis of potato MADS-box gene family is still lacking after the completion of potato genome sequencing. A genome-wide characterization, classification, and expression analysis of MADS-box transcription factor gene family was performed in this study. Results: A total of 153 MADS-box genes were identified and categorized into MIKC subfamily (MIKCC and MIKC*) and M-type subfamily (Mα, Mβ, and Mγ) based on their phylogenetic relationships to the Arabidopsis and rice MADS-box genes. The potato M-type subfamily had 114 members, which is almost three times of the MIKC members (39), indicating that M-type MADS-box genes have a higher duplication rate and/or a lower loss rate during potato genome evolution. Potato MADS-box genes were present on all 12 potato chromosomes with substantial clustering that mainly contributed by the M-type members. Chromosomal localization of potato MADS-box genes revealed that MADS-box genes, mostly MIKC, were located on the duplicated segments of the potato genome whereas tandem duplications mainly contributed to the M-type gene expansion. The potato MIKC subfamily could be further classified into 11 subgroups and the TT16-like, AGL17-like, and FLC-like subgroups found in Arabidopsis were absent in potato. Moreover, the expressions of potato MADS-box genes in various tissues were analyzed by using RNA-seq data and verified by quantitative real-time PCR, revealing that the MIKCC genes were mainly expressed in flower organs and several of them were highly expressed in stolon and tubers. StMADS1 and StMADS13 were up-regulated in the StSP6A-overexpression plants and down-regulated in the StSP6A-RNAi plant, and their expression in leaves and/or young tubers were associated with high level expression of StSP6A. Conclusion: Our study identifies the family members of potato MADS-box genes and investigate the evolution history and functional divergence of MADS-box gene family. Moreover, we analyze the MIKCC expression patterns and screen for genes involved in tuberization. Finally, the StMADS1 and StMADS13 are most likely to be downstream target of StSP6A and involved in tuber development. [ABSTRACT FROM AUTHOR]

To test the drugs - the organo-mineral additive Turmax (which contains not only basic mineral elements of nutrition but also products of metabolism of rhizosphere microorganisms) and bio-fertilizer Biovise (which contains agrobacteria), field experiment has been conducted, which involved cultivating potatoes of the Nevsky and Lubava varieties on gray forest soil for two different in weather conditions years. Variants of the experiment included control, single spraying of potato plants on shoots and during budding, double spraying of plants on shoots and during budding. As a result, it has been established that foliar treatment of the two potato plants varieties by both preparationsdespite different weather conditions, not only did not negatively affect the yield of potatoes but also significantly increased this indicator in option 2 - single spraying on shoots and in option 4 - double spraying on shoots and during budding. The significant effect of the organo-mineral drug Turmax and biofertilizerBiovise on the increase in starch, dry matter, vitamin C content in theNevsky and Lubava varieties has been observed for two years with a double treatment of the vegetative organs with the preparation (variant 4) while the content of reducing sugars in the tubers of all ripening groups led to a decrease in similar variants. The use of two types of drugs indicates a positive impact not only on the potato yield but also on its quality in years with different weather conditions. It has been revealed that for the highest yield and quality of potato, it is more effective to treat plants twice during the vegetation period - on shoots and during budding - with bothTurmax and Biovise. [ABSTRACT FROM AUTHOR]

Genome-wide association studies (GWAS) have become a powerful tool for analyzing complex traits in crop plants. The current study evaluates the efficacy of various GWAS models and methods for elucidating population structure in potato. The presence of significant population structure can lead to detection of spurious marker-trait associations, as well as mask true ones. While appropriate statistical models are needed to detect true marker-trait associations, in most published potato GWAS, a 'one model fits all traits' approach has been adopted. We have examined various GWAS models on a large association panel comprising diverse tetraploid potato cultivars and breeding lines, genotyped with single nucleotide polymorphism (SNP) markers. Phenotypic data were generated for 20 quantitative traits assessed in different environments. Best Linear Unbiased Estimates (BLUEs) for these traits were obtained for use in assessing GWAS models. Goodness of fit of GWAS models, derived using different combinations of kinship and population structure for all traits, was evaluated using Quantile-Quantile (Q-Q) plots and genomic control inflation factors (lGC). Kinship was found to play a major role in correcting population confounding effects and results advocate a 'trait-specific' fit of different GWAS models. A survey of genome-wide linkage disequilibrium (LD), one of the critical factors affecting GWAS, is also presented and our findings are compared to other recent studies in potato. The genetic material used here, and the outputs of this study represent a novel resource for genetic analysis in potato. [ABSTRACT FROM AUTHOR]

Potato ( Solanum tuberosum ) is a major food crop, while the most tissues of potato accumulates steroidal glycoalkaloids (SGAs) α-solanine and α-chaconine. Since SGAs confer a bitter taste on human and show the toxicity against various organisms, reducing the SGA content in the tubers is requisite for potato breeding. However, generation of SGA-free potato has not been achieved yet, although silencing of several SGA biosynthetic genes led a decrease in SGAs. Here, we show that the knockout of St16DOX encoding a steroid 16α-hydroxylase in SGA biosynthesis causes the complete abolition of the SGA accumulation in potato hairy roots. Nine candidate guide RNA (gRNA) target sequences were selected from St16DOX by in silico analysis, and the two or three gRNAs were introduced into a CRISPR/Cas9 vector designated as pMgP237-2A-GFP that can express multiplex gRNAs based on the pre-tRNA processing system. To establish rapid screening of the candidate gRNAs that can efficiently mutate the St16DOX gene, we used a potato hairy root culture system for the introduction of the pMgP237 vectors. Among the transgenic hairy roots, two independent lines showed no detectable SGAs but accumulated the glycosides of 22,26-dihydroxycholesterol, which is the substrate of St16DOX. Analysis of the two lines with sequencing exhibited the mutated sequences of St16DOX with no wild-type sequences. Thus, generation of SGA-free hairy roots of tetraploid potato was achieved by the combination of the hairy root culture and the pMgP237-2A-GFP vector. This experimental system is useful to evaluate the efficacy of candidate gRNA target sequences in the short-term. [ABSTRACT FROM AUTHOR]

Insight into pathogen population dynamics provides a key input for effective disease management of the potato late blight pathogen Phytophthora infestans. Phytophthora infestans populations vary from genetically complex to more simple with a few clonal lineages. The presence or absence of certain strains of P. infestans may impact the efficacy of fungicides or host resistance. Current evidence indicates that genetically, the Irish populations of P. infestans are relatively simple with a few clonal lineages. In this study, P. infestans populations were genetically characterized based on samples collected at the national centre for potato breeding during the period 2012–16. The dominance of clonal lineages within this P. infestans population was confirmed and the potential selection pressure of fungicide treatment (2013–15) and host resistance (2016) on this clonal P. infestans population was then investigated. It was found that fungicide products did not notably affect the genetic structure of sampled populations relative to samples from untreated control plants. In contrast, samples taken from several resistant potato genotypes were found to be more often of the EU_13_A2 lineage than those taken from control King Edward plants or potato genotypes with low resistance ratings. Resistant potato varieties Sarpo Mira and Bionica, containing characterized R genes, were found to strongly select for EU_13_A2 strains. [ABSTRACT FROM AUTHOR]

Sixteen potato genotypes were evaluated for processing attributes in three different environments viz., dehaulming at 70 days (E1), 90 days (E2) and 110 days (E3) after planting, at the Vegetable Research Farm, PAU, Ludhiana during autumn season of 2015-16. Stability analysis was carried out using Eberhart and Russell's model. The genotype, environment and genotype × environment (G×E) interaction effects were significant for all characters, suggesting the occurrence of considerable variability among genotypes, environments and differential response of genotypes across environments. Among genotypes, Kufri Frysona exhibited above average stability for dry matter and reducing sugars, indicating that it can perform better in unfavourable environment. Similar response was observed in Kufri Chandramukhi for free amino acids. Genotypes, MP/06-39, MS/06-819 and Kufri Pushkar were found highly stable for total phenols, total glyco-alkaloids and total tuber yield, respectively. Overall, none of the genotypes displayed stability across all the three environments for all the six characters, indicating that selection of season and purpose specific genotypes is very critical in potato. [ABSTRACT FROM AUTHOR]

DNA fingerprinting is a powerful tool for plant diversity studies, cultivar identification, and germplasm conservation and management. In breeding programs, fingerprinting and diversity analysis provide an insight into the extent of genetic variability available in the breeding material, which in turn helps breeders to maintain a pool of highly diverse genotypes by avoiding the selection of closely related parents. Oblong-long tubers with russeting skin characterize Russet potato, a primary potato market class in the United States, and especially in the western production regions. The aim of this study was to estimate the level of genetic diversity within this market class potato, utilizing clones and varieties from various breeding programs across the United States. A collection of 264 Russet and non-Russet breeding clones and varieties was fingerprinted using 23 highly polymorphic genome-wide simple sequence repeat (SSR) markers, resulting in 142 polymorphic alleles. The number of alleles produced per SSR varied from 2 to 10, with an average of 6.2 alleles per marker. The polymorphic information content and expected heterozygosity of SSRs ranged from 0.37 to 0.89 and 0.50 to 0.89 with an average of 0.77 and 0.81, respectively. Out of these 23 markers, we propose nine SSR markers best suited for fingerprinting Russet potatoes based on polymorphic information content, heterozygosity and ease of scoring. Diversity analysis of these clones suggest that there is significant diversity across the breeding material and the diversity has been evenly distributed among all the regional breeding programs. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Many studies have proven the importance of SnRK1 in the regulation of carbohydrate metabolism and plant development. Compared to Arabidopsis, much less is known about SnRK1 complexes in crop plants, and therefore, more work needs to be done to identify SnRK1 genes and to investigate their function in crop plants. Methods: In this study we identified five SnRK1-related genes in potato by analyzing the potato genome through BLAST, which encode one α-subunit isoform (stKIN), two β-subunit isoforms (stKINβ1 and stKINβ2) and two γ-subunit isoforms (stKINγ and stKINβγ). To investigate the functions of SnRK1 in the tuber development of potato, we further made overexpression and RNAi transgenic plants of these five genes. Based on these overexpression transgenic plants, the Fast protein liquid chromatography (FPLC) were employed to purify SnRK1 complexes, which were tracked by western-blot. Results: Experiments in vivo and in vitro showed that these five proteins in potato are functional SNF1/AMPK/SnRK1-related proteins. The SnRK1 activity decreased by 60% in the RNAi transgenic lines of stKIN; the starch content increased by 25% in the overexpression transgenic lines of stKIN, compared to that in the wild-type lines, whereas there is no significant difference in SnRK1 activity and starch content in the RNAi transgenic or overexpression lines of stKINβ1, stKINβ2, stKINγ and stKINβγ. In addition, we found that a few different SnRK1 complexes are present in potato by partially purifying SnRK1 complexes from these overexpression transgenic plants. Conclusions: Five functional SnRK1-related genes were identified in potato, including three novel genes, which encode one α-subunit isoform (stKIN), two β-subunit isoforms (stKINβ1 and stKINβ2) and two γ-subunit isoforms (stKINγ and stKINβγ). We found that a few SnRK1 related genes are present in potato tuber, which form several different SnRK1 isoenzymes. We found that stKIN is the primary α subunit of SnRK1 in potato tuber and plays important roles in the development of potato tubers. [ABSTRACT FROM AUTHOR]

Breeders rely on genetic integrity of material from genebanks; however, admixture, mislabeling, and errors in original data can occur and be detrimental. Two hundred and fifty accessions, representing paired samples consisting of original mother plants and their in vitro counterparts from the cultivated potato collection at the International Potato Center (CIP) were fingerprinted using the Infinium 12K V2 Potato Array to confirm genetic identity of the accessions and evaluate genetic diversity of the potato collection. Diploid, triploid, and tetraploid accessions were included, representing seven cultivated potato taxa (based on Hawkes, 1990). Fingerprints between voucher mother plants maintained in the field and in vitro clones of the same accession were used to evaluate identity, relatedness, and ancestry using hierarchal clustering and model-based Bayesian admixture analyses. Generally, in vitro and field clones of the same accession grouped together; however, 11 (4.4%) accessions were mismatches genetically, and in some cases the SNP data revealed the identity of the mixed accession. SNP genotypes were used to assess genetic diversity and to evaluate inter- and intraspecific relationships along with determining population structure and hybrid origins. Phylogenetic analyses suggest that the triploids included in this study are genetically similar. Further, some genetic redundancies among individual accessions were also identified along with some putative misclassified accessions. Accessions generally clustered together based on taxonomic classification and ploidy level with some deviations. STRUCTURE analysis identified six populations with significant gene flow among the populations, as well as revealed hybrid taxa and accessions. Overall, the Infinium 12K V2 Potato Array proved useful in confirming identity and highlighting the diversity in this subset of the CIP collection, providing new insights into the accessions evaluated. This study provides a model for genetic identity of plant genetic resources collections as mistakes in conservation of these collections and in genebanks is a reality. For breeders and other users of these collections, confirmed identity is critical, as well as for quality management programs and to provide insights into the accessions evaluated. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum) is a staple food crop and is considered one of the main sources of carbohydrates worldwide. Late blight (Phytophthora infestans) and common scab (Streptomyces scabies) are two of the primary production constraints faced by potato farming. Previous studies have identified a few resistance genes for both late blight and common scab; however, these genes explain only a limited fraction of the heritability of these diseases. Genomic selection has been demonstrated to be an effective methodology for breeding value prediction in many major crops (e.g., maize and wheat). However, the technology has received little attention in potato breeding. We present the first genomic selection study involving late blight and common scab in tetraploid potato. Our data involves 4,110 (Single Nucleotide Polymorphisms, SNPs) and phenotypic field evaluations for late blight (n=1,763) and common scab (n=3,885) collected in seven and nine years, respectively. We report moderately high genomic heritability estimates (0.46 ± 0.04 and 0.45 ± 0.017, for late blight and common scab, respectively). The extent of genotype-by-year interaction was high for late blight and low for common scab. Our assessment of prediction accuracy demonstrates the applicability of genomic prediction for tetraploid potato breeding. For both traits, we found that more than 90% of the genetic variance could be captured with an additive model. For common scab, the highest prediction accuracy was achieved using an additive model. For late blight, small but statistically significant gains in prediction accuracy were achieved using a model that accounted for both additive and dominance effects. Using whole-genome regression models we identified SNPs located in previously reported hotspots regions for late blight, on genes associated with systemic disease resistance responses, and a new locus located in a WRKY transcription factor for common scab. [ABSTRACT FROM AUTHOR]

The article presents the results of introgression of valuable genes from wild and cultivated species of Solanum and varieties of the world collection (CIP) to selection varieties in the production of backcross hybrids, selection of recombinants in backcross generations and in offspring from crossbred crosses among themselves, as well as special parent lines for implementation of programs in various areas of potato breeding. Studies were conducted to determine the effectiveness of different types of crossing during backcrossing in the frequency of occurrence of recombinant forms with high rates of polygenic traits in the hybrid progeny. Hybrids-backcrosses for immunity to virus Y, field resistance to late blight and resistance to the pathogen Ro1 of the golden potato nematode were evaluated by the method of artificial infection in pot-plant in a greenhouse. Analysis of hybrid progeny for starch content and suitability for processing by the color of chips was carried out under laboratory conditions. According to the results of the analysis of the pedigrees of 10 varieties of potato originating from the two forms of S. chacoense, a high efficiency of recurrent accumulation crosses providing introgression of the dominant immunity genes to the virus Y is revealed, as well as resistance to alternaria, heat and drought. Medium-late varieties with high field resistance of leaves and tubers were created on the basis of unstable to the late blight hybrid (F1 S. chacoense 55 d x Agra) and 3 recurrent crosses. In this case, varieties with medium field resistance to late blight participated in backcrossing. When assessing the collection of wild species for resistance to the pathogen Ro1 of the golden potato nematode, only one new source of S. chacoense 58 d was detected. Analysis of the cleavage in resistance to nematode among populations from the crossing of three-species hybrids (vrn x chc) x tbr and backcross hybrids (vrn x chc) x tbr2 confirmed control of the trait by one dominant gene, which facilitates selection for this feature. Based on the analysis of the frequency of occurrence of hybrids with different starch content in the fissile offspring, it is established that this feature is controlled by a small amount of pure additively acting genes. In the hybrid populations studied, the symmetrical frequency distribution, the presence of transgressions, and the high correlation between the average starch content of parental forms and the average offspring were observed. In a comparative assessment of 36 hybrid populations on the suitability for processing for potato products, methods for selecting parental forms for crossing and timing of the evaluation of the trait in different periods of tuber storage have been identified. Twenty-two hybrids are identified that are suitable for processing during the entire storage period without reconditioning. An increase in the efficiency of the selection process was noted in the repeated use of identical hybrid populations for selection in various environmental and geographical conditions, which significantly reduces the financial costs of creating a variety. [ABSTRACT FROM AUTHOR]

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The cultivated potato (Solanum tuberosum) has a complex genetic structure due to its autotetraploidy and vegetative propagation which leads to accumulation of mutations and a highly heterozygous genome. A high degree of heterozygosity has been considered to be the main driver of fitness and agronomic trait performance in potato improvement efforts, which is negatively impacted by genetic load. To understand the genetic landscape of cultivated potato, we constructed a gynogenic dihaploid (2n = 2x = 24) population from cv. Superior, prior to development of a high-density genetic map containing 12,753 single nucleotide polymorphisms (SNPs). Common quantitative trait loci (QTL) were identified for tuber traits, vigor and height on chromosomes 2, 4, 7, and 10, while specific QTL for number of inflorescences per plant, and tuber shape were present on chromosomes 4, 6, 10, and 11. Simplex rather than duplex loci were mainly associated with traits. In general, the Q allele (main effect) detected in one or two homologous chromosomes was associated with lower mean trait values suggesting the importance of dosage allelic effects, and the presence of up to two undesired alleles in the QTL region. Loss of heterozygosity has been associated with a lower rate of fitness, yet no correlation between the percent heterozygosity and increased fitness or agronomic performance was observed. Based upon linkage phase, we reconstructed the four homologous chromosome haplotypes of cv. Superior. revealing heterogeneity throughout the genome yet nearly duplicate haplotypes occurring among the homologs of particular chromosomes. These results suggest that the potentially deleterious mutations associated with genetic load in tetraploid potato could be mitigated by multiple loci which is consistent with the theory that epistasis complicates the identification of associations between markers and phenotypic performance. [ABSTRACT FROM AUTHOR]

Genotyping-by-sequencing (GBS) potentially offers a cost-effective alternative for SNP discovery and genotyping. Here, we report the exploration of GBS in tetraploid potato. Both ApeKI and PstI/ MspI enzymes were used for library preparation on eight diverse potato genotypes. ApeKI yielded more markers than PstI/ MspI but provided a lower read coverage per marker, resulting in more missing data and limiting effective genotyping to the tetraploid mode. We then assessed the accuracy of these SNPs by comparison with SolCAP data (5824 data points in diploid mode and 3243 data points in tetraploid mode) and found the match rates between genotype calls was 90.4% and 81.3%, respectively. Imputation of missing data did not prove very accurate because of incomplete haplotype discovery, suggesting caution in setting the allowance for missing data. To further assess the quality of GBS-derived data, a genome-wide association analysis was performed for flower color on 318 clones (with ApeKI). A strong association signal on chromosome 2 was obtained with the most significant SNP located in the middle of the dihydroflavonol 4-reductase ( DFR) gene. We conclude that an appropriate choice of enzyme for GBS library preparation makes it possible to obtain high-quality SNPs in potato and will be helpful for marker-assisted genomics. [ABSTRACT FROM AUTHOR]