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Potato is the third most important food crop in the world in terms of adaptability, yield potential, and nutritional advantages. This study aimed to conduct potato breeding work for cultivation in Kazakhstan; potato breeding for further processing into chips with cultivation in the northern regions; and the selection of potatoes for processing into frozen French fries with cultivation in the southern and south-eastern regions. Potato varieties (Fontane, Santana, and Punchy) were used as reference varieties to check molecular markers linked to maturity, tuber shape, and flesh color. A total of 42 potato breeding lines crossed from Yagodnyi 19 and CIP clone 397079-6 were used in this study to identify prospective breeding lines. The research was carried out between 2023 and 2024 and under greenhouse conditions. According to the results of molecular analysis and phenotypic data, 21 breeding lines were identified as prospective potato breeding lines. The majority of these potato breeding lines had a round tuber shape and were recommended for chip processing. Three breeding lines had a long oval tuber shape, making them suitable for French fries. Six breeding lines with short-oval and oval tuber shapes were found for consumer potato processing. It is recommended that the breeding process and studies of biochemical properties are continued in all of these identified potato breeding lines. [ABSTRACT FROM AUTHOR]

Grafting is a traditional research and crop production technique used to study the long-distance movement of molecules, reduce disease susceptibility, and improve yield, quality, and nutrient content. Tomato/potato grafts are rare examples of successful interspecies grafting, even resulting in commercially available products. Nevertheless, information on the effect of tomato on the quality parameters of potato tubers is scarce. In this study, the tomato cultivar 'Mobil' was grafted with the potato cultivars 'White Lady', 'Hópehely', and 'Désirée', and the phenotype, metabolite composition, and starch and protein contents of the tubers were analysed. Anthocyanins were isolated from the tuber skins, and the expression level of the transcription factor ANTHOCYANIN1 (StAN1) was evaluated. Out of the 112 identified metabolites, the concentrations of twelve compounds were altered in the same direction in all three cultivars. Compared to the self-grafted control, the starch content of tubers was increased in each cultivar, while the protein level remained unaltered in 'White Lady' and 'Hópehely'. The oval tubers became roundish. The tomato scion increased the anthocyanin content of 'Hópehely' and 'Désirée' tuber skins, which was correlated with the upregulation of StAN1 expression. These results indicate that tomato scion has a significant impact on the quality parameters of potato tubers. [ABSTRACT FROM AUTHOR]

Grafting is a traditional research and crop production technique used to study the long-distance movement of molecules, reduce disease susceptibility, and improve yield, quality, and nutrient content. Tomato/potato grafts are rare examples of successful interspecies grafting, even resulting in commercially available products. Nevertheless, information on the effect of tomato on the quality parameters of potato tubers is scarce. In this study, the tomato cultivar ‘Mobil’ was grafted with the potato cultivars ‘White Lady’, ‘Hópehely’, and ‘Désirée’, and the phenotype, metabolite composition, and starch and protein contents of the tubers were analysed. Anthocyanins were isolated from the tuber skins, and the expression level of the transcription factor ANTHOCYANIN1 (StAN1) was evaluated. Out of the 112 identified metabolites, the concentrations of twelve compounds were altered in the same direction in all three cultivars. Compared to the self-grafted control, the starch content of tubers was increased in each cultivar, while the protein level remained unaltered in ‘White Lady’ and ‘Hópehely’. The oval tubers became roundish. The tomato scion increased the anthocyanin content of ‘Hópehely’ and ‘Désirée’ tuber skins, which was correlated with the upregulation of StAN1 expression. These results indicate that tomato scion has a significant impact on the quality parameters of potato tubers.

The OVATE family proteins (OFPs) are plant-specific proteins that modulate diverse aspects of plant growth and development. In tomato, OFP20 has been shown to interact with TONNEAU1 Recruiting Motif (TRM) proteins to regulate fruit shape. In this study, we demonstrated that the mutation of StOFP20 caused a shift from round to oval shaped tubers in a diploid accession C151, supporting the role of StOFP20 in controlling tuber shape. Its expression reached a maximum in the tuber initiation stage and then decreased as the tuber develops. To help elucidate the mechanism of tuber shape regulation by StOFP20, 27 TONNEAU1 Recruiting Motif (TRM) proteins were identified and 23 of them were successfully amplified in C151. A yeast two-hybrid assay identified three TRM proteins that interacted with StOFP20, which was confirmed by firefly luciferase complementation in tobacco leaves. The OVATE domain was indispensable for the interactions, while the necessity of the M10 motif in TRM proteins varied among the interactions between StOFP20 and the three TRMs. In summary, both StOFP20 and SlOFP20 directed interactions with TRM proteins, but the corresponding interactants were not completely consistent, implying that they exert regulatory roles through mechanisms that are only partially overlapping.

Potato is one of the world's most important food crops, with a time-consuming breeding process. In this study, we performed a genome-wide association (GWAS) analysis of the two important traits of potato tuber shape and eye depth, using the tetraploid potato genome (2n=4x=48) as a reference. A total of 370 potatoes were divided into three subgroups based on the principal component analysis and evolutionary tree analysis. The genetic diversity within subgroups is low (5.18x10-5, 4.36x10-5 and 4.24x10-5). Genome-wide linkage disequilibrium (LD) analysis showed that their LD is about 60 Kb. GWAS analysis identified that 146 significant single nucleotide polymorphism (SNP) loci at Chr01A1:34.44-35.25 Mb and Chr02A1:28.35-28.54 Mb regions are significantly associated with potato tuber shape, and that three candidate genes that might be related to potato tuber traits, PLATZ transcription factor, UTP-glucose-1-phosphate uridylyltransferase and FAR1 DNA-binding domain, are in the association region of Chr02A1. GWAS analysis identified 53 significant SNP loci at Chr05A2: 49.644-50.146 Mb and Chr06A2: 25.866-26.384 Mb regions with robust associations with potato tuber eye depth. Hydrolase and methyltransferases are present in the association region of Chr05A2, and three CYPs are present in the association region of Chr06A2. Our findings suggested that these genes are closely associated with potato tuber shape and eye depth. Our study identified molecular markers and candidate genes for improving tetraploid potato tuber shape and eye depth and provided ideas and insights for tetraploid potato breeding. [ABSTRACT FROM AUTHOR]

Tuber shape is one of the most important traits for potato breeding. Since poor or irregular shape increases the difficulty of handling and processing, researching the inheritance of potato tuber shape for potato breeding is highly important. To efficiently identify QTL for tuber shape, a diploid potato population (PM7) was generated by self-pollinated M6 (S. chacoense). A QTL TScha6 for tuber shape was identified by the QTL-seq approach at 50.91-59.93 Mb on chromosome 6 in the potato DM reference genome. To confirm TScha6, four SSR and twenty CAPS markers around the QTL were developed and the TScha6 was narrowed down to an interval of ~ 1.85 Mb. The CAPS marker C6-58.27&#95665 linked to TScha6 was then used to screen 86 potato cultivars and advanced breeding lines. The tuber length/width (LW) ratio was significantly correlated with the presence/absence of C6-58.27&#95665, and the correlation coefficient was r = 0.55 (p < 0.01). These results showed that C6-58.27&#95665 could be applied in marker-assisted selection (MAS) for tuber shape breeding in the future. Our research sets the important stage for the future cloning of the tuber shape gene and utilities of the marker in the breeding program. [ABSTRACT FROM AUTHOR]

For sustainable food production, labor-saving cultivation systems are required. Yam, a major food crop, is cultivated mostly with supports such as stakes (staking), which increases tuber yield (TY) but involves high material and labor costs. We, therefore, focused on non-staking water yam cultivation, in which no stakes are used. The effects of different cultivation methods (staking vs. non-staking) on TY, yield components, shoot traits, and tuber shape of six cultivars were investigated in a two-year field experiment, and phenotypic traits related to yielding ability in non-staking cultivation were analyzed. Averaged across years and cultivars, TY was significantly lower (by 19%) in non-staking than in staking cultivation because of smaller single-tuber weight. TY was significantly affected by the cultivation × cultivar interaction. We found no difference among cultivars in staking cultivation. In non-staking cultivation, Yamatomakousha and Shirokoushaman 1 cultivars had higher TY than the other cultivars, which was similar to their TY in staking cultivation. Shoot dry weight and vine number were closely associated with TY in both cultivations, whereas lower tuber length-to-width ratio was strongly related to higher TY only in non-staking. Tubers of Yamatomakousha and Shirokoushaman 1 were more rounded than those of other cultivars. In non-staking cultivation, these two cultivars showed a higher vine number and, thus, maintained higher TY owing to higher above-ground growth. Therefore, rounded tubers and high vine number are target traits for non-staking cultivation of water yam. [ABSTRACT FROM AUTHOR]

Tuber shape is one of the most important quality traits in potato appearance. Since poor or irregular shape results in higher costs for processing and influences the consumers’ willingness to purchase, breeding for shape uniformity and shallow eye depth is highly important. Previous studies showed that the major round tuber shape controlling locus, the Ro locus, is located on chromosome 10. However, fine mapping and cloning of tuber shape genes have not been reported. In this study, the analyses of tissue sectioning and transcriptome sequencing showed that the developmental differences between round and elongated tuber shapes begin as early as the hook stage of the stolon. To fine map tuber shape genes, a high-density genetic linkage map of the Ro region on chromosome 10 based on a diploid segregating population was constructed. The total length of the genetic linkage map was 25.8 cM and the average marker interval was 1.98 cM. Combined with phenotypic data collected from 2014 to 2017, one major quantitative trait locus (QTL) for tuber shape was identified, which explained 61.7–72.9% of the tuber shape variation. Through the results of genotyping and phenotypic investigation of recombinant individuals, Ro was fine mapped in a 193.43 kb interval, which contained 18 genes. Five candidate genes were preliminarily predicted based on tissue sections and transcriptome sequencing. This study provides an important basis for cloning Ro gene(s).

Consumer demand for specialty market potatoes has been growing. Cultivated South American diploid potatoes possess great variation for skin and flesh colors, shape, and taste. A long-day adapted population of Solanum tuberosum groups Phureja and Stenotomum (phu-stn) was evaluated for characteristics associated with the type known as papa criolla or papa amarilla in South America. Tubers have intense yellow flesh and may be fried or roasted and eaten whole. A U.S. northern location (Maine), representative of a seed growing region, and two southern locations (Florida and New Mexico), representative of potato growing regions near large Hispanic populations, evaluated yellow-fleshed clones selected within a phu-stn population. Agreement between selectors at two locations was greater than 50%. Tuber skin color and shape were highly correlated between locations; flesh color and tuber dormancy moderately so; eye depth had low correlation between locations; and appearance and skin texture had low or no correlation between locations. Tuber dormancy was generally short, but a few longer dormant clones were identified. There were significant differences among clones for yields, with the highest yields occurring in Maine. More intense evaluations are planned for a subset of these clones before possible release as new varieties. Future breeding efforts will be undertaken to lengthen tuber dormancy in this population. [ABSTRACT FROM AUTHOR]

Potato (Solanum tuberosum) production generally requires added nitrogen (N), which is costly and potentially environmentally damaging. One path to limiting N application is breeding N efficient potatoes. Effective use of nitrogen, across crops, is typically characterized in terms of yield. However, tuber quality characteristics affect potato marketability, especially for red fresh market potatoes. While optimal N rates maximize yield, the genotype-specific effect of N on tuber quality traits is unclear. In order to highlight quality traits effected by N, identify germplasm with lower N requirements, and determine optimal N rates for red-skinned clones, we conducted a variable N rate experiment over two years in Minnesota. Eight red fresh market genotypes were grown in RCB factorial design with five nitrogen application rates ranging from 0 to 81.6 kg/ha. Best linear unbiased estimates were calculated for yield, skin color, skin set, and tuber shape. The models for yield and quality traits included significant genotype by N rate interaction effects, suggesting that there is variation in the way clones respond to N. Established varieties were more responsive to added N than breeding lines. Similarly, established varieties tended to produce more oblong tubers under higher N conditions, while the breeding lines remained round. Color traits also responded to N in a genotype-specific way, while the interaction effect for other traits depended on unmeasured environmental factors. No clone exhibited increased yield above the 54.4 kg/ha rate. Our results suggest that the 81.6 kg/ha rate produced less favorable phenotypes for all traits.

Potato is one of the world's most important food crops, with a time-consuming breeding process. In this study, we performed a genome-wide association (GWAS) analysis of the two important traits of potato tuber shape and eye depth, using the tetraploid potato genome (2n=4x=48) as a reference. A total of 370 potatoes were divided into three subgroups based on the principal component analysis and evolutionary tree analysis. The genetic diversity within subgroups is low (5.18×10 -5 , 4.36×10 -5 and 4.24×10 -5 ). Genome-wide linkage disequilibrium (LD) analysis showed that their LD is about 60 Kb. GWAS analysis identified that 146 significant single nucleotide polymorphism (SNP) loci at Chr01A1:34.44-35.25 Mb and Chr02A1:28.35-28.54 Mb regions are significantly associated with potato tuber shape, and that three candidate genes that might be related to potato tuber traits, PLATZ transcription factor, UTP-glucose-1-phosphate uridylyltransferase and FAR1 DNA-binding domain, are in the association region of Chr02A1. GWAS analysis identified 53 significant SNP loci at Chr05A2: 49.644-50.146 Mb and Chr06A2: 25.866-26.384 Mb regions with robust associations with potato tuber eye depth. Hydrolase and methyltransferases are present in the association region of Chr05A2, and three CYPs are present in the association region of Chr06A2. Our findings suggested that these genes are closely associated with potato tuber shape and eye depth. Our study identified molecular markers and candidate genes for improving tetraploid potato tuber shape and eye depth and provided ideas and insights for tetraploid potato breeding., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zhao, Zou, Deng, Xia, Jiang, Zhang, Ma, Dong, He, Na, Wang, Xia and Wang.)

Nos últimos anos, foi despertado um grande interesse para o processamento da batata na forma de fritura no Brasil. Visando à obtenção de cultivares nacionais que atendam aos padrões de qualidade culinária exigidos pelas indústrias de processamento, os programas de melhoramento de batata têm estabelecido estratégias para a redução de custos e de tempo. Realizou-se este trabalho com o objetivo de avaliar a eficiência da seleção precoce de clones de batata (Solanum tuberosum L.) para características de importância ao processamento na forma de fritura. Os caracteres avaliados foram: peso específico de tubérculos, índices de formato de tubérculos e notas na glico-fita, mediante correlações entre as gerações seedling (S), primeira geração clonal (C-1) e segunda geração clonal (C-2), entre clones e entre famílias. Os experimentos foram conduzidos no sul do estado de Minas Gerais, Brasil. As correlações foram significativas na maioria dos casos, porém, baixas e geralmente apresentaram maiores valores quando consideradas entre famílias, indicando a baixa eficiência da seleção precoce entre clones. Assim, deve ser praticada somente para se eliminar as piores famílias. A correlação para o índice de formato de tubérculo (comprimento/diâmetro maior) entre as gerações S e C-1 foi de 0,51 entre clones e 0,77 entre famílias e ambos os valores foram significativos, indicando uma razoável eficiência da seleção precoce para esse caráter tanto entre clones como entre famílias.The purpose of this research was to assess the effectiveness of early selection for tuber specific gravity, tuber shape index, and reducing sugars content in the tubers of potato (Solanum tuberosum L.) clones. The experiments were conducted in the south of the State of Minas Gerais, Brazil. Correlation coefficients were determined for the seedling (S) and first (FCG) and second (SCG) clonal generations at the clones and families levels. In general, correlation coefficients were significant but of low magnitude. There was a tendency of higher coefficients for the families, indicating low efficiency in doing early selection of the clones. However, mild selection at the family level could be done to eliminate the worst families. The correlation coefficient for tuber shape index (length/diameter) between S and FCG was 0.51 at the clone level and 0.77 at the family level, showing the feasibility to select for this trait in the early generations, both for clones and families.

Background: Tuber appearance is highly variable in the Andean cultivated potato germplasm. The diploid backcross mapping population 'DMDD' derived from the recently sequenced genome 'DM' represents a sample of the allelic variation for tuber shape and eye depth present in the Andean landraces. Here we evaluate the utility of morphological descriptors for tuber shape for identification of genetic loci responsible for the shape and eye depth variation. Results: Subjective morphological descriptors and objective tuber length and width measurements were used for assessment of variation in tuber shape and eye depth. Phenotypic data obtained from three trials and male-female based genetic maps were used for quantitative trait locus (QTL) identification. Seven morphological tuber shapes were identified within the population. A continuous distribution of phenotypes was found using the ratio of tuber length to tuber width and a QTL was identified in the paternal map on chromosome 10. Using toPt-437059, the marker at the peak of this QTL, the seven tuber shapes were classified into two groups: cylindrical and non-cylindrical. In the first group, shapes classified as 'compressed', 'round', 'oblong', and 'long-oblong' mainly carried a marker allele originating from the male parent. The tubers in this group had deeper eyes, for which a strong QTL was found at the same location on chromosome 10 of the paternal map. The non-cylindrical tubers classified as 'obovoid', 'elliptic', and 'elongated' were in the second group, mostly lacking the marker allele originating from the male parent. The main QTL for shape and eye depth were located in the same genomic region as the previously mapped dominant genes for round tuber shape and eye depth. A number of candidate genes underlying the significant QTL markers for tuber shape and eye depth were identified. Conclusions: Utilization of a molecular marker at the shape and eye depth QTL enabled the reclassification of the variation in general tuber shape to two main groups. Quantitative measurement of the length and width at different parts of the tuber is recommended to accompany the morphological descriptor classification to correctly capture the shape variation. [ABSTRACT FROM AUTHOR]

Tuber shape is one of the most important traits for potato breeding. Since poor or irregular shape increases the difficulty of handling and processing, researching the inheritance of potato tuber shape for potato breeding is highly important. To efficiently identify QTL for tuber shape, a diploid potato population (PM7) was generated by self-pollinated M6 ( S. chacoense ). A QTL TScha6 for tuber shape was identified by the QTL-seq approach at 50.91-59.93 Mb on chromosome 6 in the potato DM reference genome. To confirm TScha6, four SSR and twenty CAPS markers around the QTL were developed and the TScha6 was narrowed down to an interval of ~ 1.85 Mb. The CAPS marker C6-58.27&#95;665 linked to TScha6 was then used to screen 86 potato cultivars and advanced breeding lines. The tuber length/width (LW) ratio was significantly correlated with the presence/absence of C6-58.27&#95;665, and the correlation coefficient was r = 0.55 (p < 0.01). These results showed that C6-58.27&#95;665 could be applied in marker-assisted selection (MAS) for tuber shape breeding in the future. Our research sets the important stage for the future cloning of the tuber shape gene and utilities of the marker in the breeding program., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Huang, Dong, Zhao, Zhao, Li, Li and Song.)

Tuber shape is one of the most important quality traits in potato appearance. Since poor or irregular shape results in higher costs for processing and influences the consumers' willingness to purchase, breeding for shape uniformity and shallow eye depth is highly important. Previous studies showed that the major round tuber shape controlling locus, the Ro locus, is located on chromosome 10. However, fine mapping and cloning of tuber shape genes have not been reported. In this study, the analyses of tissue sectioning and transcriptome sequencing showed that the developmental differences between round and elongated tuber shapes begin as early as the hook stage of the stolon. To fine map tuber shape genes, a high-density genetic linkage map of the Ro region on chromosome 10 based on a diploid segregating population was constructed. The total length of the genetic linkage map was 25.8 cM and the average marker interval was 1.98 cM. Combined with phenotypic data collected from 2014 to 2017, one major quantitative trait locus (QTL) for tuber shape was identified, which explained 61.7–72.9% of the tuber shape variation. Through the results of genotyping and phenotypic investigation of recombinant individuals, Ro was fine mapped in a 193.43 kb interval, which contained 18 genes. Five candidate genes were preliminarily predicted based on tissue sections and transcriptome sequencing. This study provides an important basis for cloning Ro gene(s). [ABSTRACT FROM AUTHOR]

Potato breeding aims at breeding diversified cultivars not only suitable for different purposes, but also resistant to diseases, such as late blight caused by Phytophthora infestans, which is a major constraint in potato production. Resistance to P. infestans has been previously introduced into the diploid hybrid population 98-21 from Solanum verrucosum and Solanum microdontum. In the present study, we assessed the segregation of tuber dormancy, tuber shape, regularity of tuber shape, eye depth and flesh colour in this population. Quantitative Trait Loci (QTLs) affecting these important quality traits were tagged using the genetic map developed for this population to locate QTLs for late blight resistance. The most prominent QTL for dormancy was detected on chromosome II and explained 7.1% of the variance. The most important QTLs for tuber eye depth, flesh colour, shape and shape regularity were identified on chromosomes X ( R2 = 14.7%), IV ( R2 = 5.8%), II ( R2 = 8.0%) and III ( R2 = 10.4%) respectively. All traits were also affected by minor QTLs. The obtained results improve our understanding of the inheritance of traits relevant for variety development in potato. [ABSTRACT FROM AUTHOR]

Thirty-three populations of Andigena potatoes developed by 11 × 3 (line × tester) mating were studied from seedling to third clonal generations for number of tubers, average tuber weight, tuber yield, plant vigour, predominant tuber shape, predominant tuber size and uniformity in tuber shape, uniformity in tuber size and uniformity in tuber colour. Inter-generation correlation coefficients for progeny means, general combining ability, specific combining ability, heterosis and heterobeltiosis were computed for various characters. Magnitude of inter-generation correlation coefficients showed that various parameters for uniformity in tuber shape, uniformity in tuber size, uniformity in tuber colour, predominant tuber shape and predominant tuber size could be reliably estimated in early generations starting from the seedling generation. The parameters for tuber yield, average tuber weight and tuber number could only be reliably estimated from second clonal generation onward. Repeatability of progeny means showed that negative selection for tuber yield and average tuber weight could be initiated from first clonal generation and for tuber number from second clonal generation. Plant vigour was found to be a highly inconsistent character. [ABSTRACT FROM AUTHOR]

About 13,000 somaclones of 17 cultivars and clones of potato were obtained from in vitro callus cultures and individually planted in a greenhouse, followed by tuber generations grown in the field. These plants were subjected to the multistage selection procedure commonly used in potato breeding. Over a period of five years and three field generations the tuber number, size, shape, eye depth, starch content, starch yield and tuber appearance of these somaclones were assessed and compared with that of the controls. These characters varied depending on donor genotype and trait. The frequency of variants was assessed and there were acceptable proportions of desirable abberrants and invariants among the somaclones. Depending on trait the average gain rate for all donor genotypes ranged between 0.2 and 2.3% for-deviants, between 12.2 and 15.5% for invariants and between 0.1–1.4% for +deviants. It is concluded that this technique should be used into potato breeding programmes to improve commercially important characteristics of specific cultivars and breeding clones. [ABSTRACT FROM AUTHOR]

Copyright of American Potato Journal is the property of Springer Nature 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.)

Copyright of American Potato Journal is the property of Springer Nature 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.)

Copyright of American Potato Journal is the property of Springer Nature 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.)

Tubers from six cultivars of potato grown in irrigated and droughted conditions were examined to show whether observed differences in grade distributions were simple consequences of differences in yield or were the results of changes in tuber shape or in the relative variability (Rv=σ/μ) of the distributions. Differences in tuber shape, indicated by the relations between tuber size (mm) and weight, were statistically significant but were insufficient to cause measurable changes in the grade distributions. There was a range of values of Rv but drought had no statistically significant effect on Rv and may only affect it by influencing the numbers of tubers set. The main effect of drought on the distribution of tuber sizes was through its effect on total yield and hence on mean tuber size. Yield and number of tubers define a unique tuber-size distribution regardless of the soil moisture stress experienced by the crop. [ABSTRACT FROM AUTHOR]

Copyright of Potato Research is the property of Springer Nature 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 (Solanum tuberosum) production generally requires added nitrogen (N), which is costly and potentially environmentally damaging. One path to limiting N application is breeding N efficient potatoes. Effective use of nitrogen, across crops, is typically characterized in terms of yield. However, tuber quality characteristics affect potato marketability, especially for red fresh market potatoes. While optimal N rates maximize yield, the genotype-specific effect of N on tuber quality traits is unclear. In order to highlight quality traits effected by N, identify germplasm with lower N requirements, and determine optimal N rates for red-skinned clones, we conducted a variable N rate experiment over two years in Minnesota. Eight red fresh market genotypes were grown in RCB factorial design with five nitrogen application rates ranging from 0 to 81.6 kg/ha. Best linear unbiased estimates were calculated for yield, skin color, skin set, and tuber shape. The models for yield and quality traits included significant genotype by N rate interaction effects, suggesting that there is variation in the way clones respond to N. Established varieties were more responsive to added N than breeding lines. Similarly, established varieties tended to produce more oblong tubers under higher N conditions, while the breeding lines remained round. Color traits also responded to N in a genotype-specific way, while the interaction effect for other traits depended on unmeasured environmental factors. No clone exhibited increased yield above the 54.4 kg/ha rate. Our results suggest that the 81.6 kg/ha rate produced less favorable phenotypes for all traits. [ABSTRACT FROM AUTHOR]