Response and Adaptive Mechanism of Flavonoids in Pigmented Potatoes at Different Altitudes.

Altitude is an important ecological factor affecting plant physiology and ecology, material metabolism and gene expression. Tuber color changes were observed in purple and red potatoes growing at four different elevations ranging from 1,800 ± 50 to 3,300 ± 50 m in the Tiger Leaping Gorge area of Yunnan Province. The results showed that the total phenol content, total flavone content, total anthocyanin content and biological yield of anthocyanin increased with increasing altitude until 2,800 ± 50 m, and the highest anthocyanin content were detected in the purple potato Huaxinyangyu and the red potato Jianchuanhong at the flowering stage and budding stage, respectively. Combined transcriptomic and metabolomic analyses revealed that the content and diversity of flavonoids are associated with genes expression via the promotion of propane metabolism to improve potato adaptation to different altitudes. These results provide a foundation for understanding the coloring mechanism and creating new potato germplasms with high resistance and good quality via genetic manipulation.

Effects of appropriate low-temperature treatment on the yield and quality of pigmented potato (Solanum tuberosum L.) tubers.

Temperature is one of the important environmental factors affecting plant growth, yield and quality. Moreover, appropriately low temperature is also beneficial for tuber coloration. The red potato variety Jianchuanhong, whose tuber color is susceptible to temperature, and the purple potato variety Huaxinyangyu, whose tuber color is stable, were used as experimental materials and subjected to 20 °C (control check), 15 °C and 10 °C treatments during the whole growth period. The effects of temperature treatment on the phenotype, the expression levels of structural genes related to anthocyanins and the correlations of each indicator were analyzed. The results showed that treatment at 10 °C significantly inhibited the potato plant height, and the chlorophyll content and photosynthetic parameters in the leaves were reduced, and the enzyme activities of SOD and POD were significantly increased, all indicating that the leaves were damaged. Treatment at 10 °C also affected the tuberization of Huaxinyangyu and reduced the tuberization and coloring of Jianchuanhong, while treatment at 15 °C significantly increased the stem diameter, root-to-shoot ratio, yield and content of secondary metabolites, especially anthocyanins. Similarly, the expression of structural genes were enhanced in two pigmented potatoes under low-temperature treatment conditions. In short, proper low temperature can not only increase yield but also enhance secondary metabolites production. Previous studies have not focused on the effects of appropriate low-temperature treatment during the whole growth period of potato on the changes in metabolites during tuber growth and development, these results can provide a theoretical basis and technical guidance for the selection of pigmented potatoes with better nutritional quality planting environment and the formulation of cultivation measures.

Potato Consumption and All-Cause and Cardiovascular Disease Mortality - A Long-Term Follow-Up of a Norwegian Cohort.

BACKGROUND: Potatoes are a staple food in many traditional cuisines, yet their impact on long-term risk of cardiovascular disease (CVD) and mortality is unclear, hampering evidence-based dietary guidelines. OBJECTIVES: This study aimed to examine the association between potato consumption and all-cause and CVD-specific death over a substantial follow-up period within a cohort predominantly consuming boiled potatoes. METHODS: Adults from 3 Norwegian counties were invited to 3 health screenings in 1974-1988 (>80% attendance). Dietary data were collected using semiquantitative food frequency questionnaires at each screening to categorize weekly potato consumption (≤6, 7-13, or ≥14 potatoes/wk) and calculate daily cumulative mean intakes (grams/day). Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using multivariable Cox regression to estimate HRs and 95% CIs for the association between potato consumption and risk of death from all causes, CVD, ischemic heart disease (IHD), and acute myocardial infarction (AMI). RESULTS: Among 77,297 participants with a mean baseline age of 41.1 y (range: 18.0-63.9 y), we observed 27,848 deaths, including 9072 deaths due to CVD, over a median follow-up of 33.5 y. Participants who consumed ≥14 potatoes/wk had a lower risk of all-cause death compared with those consuming ≤6 potatoes/wk (HR: 0.88; 95% CI: 0.84, 0.93). Potato consumption was associated with a minor, inverse risk of death due to CVD, IHD, and AMI. In continuous analyses of cumulative intakes, each 100 g/d increment was associated with 4% lower risk of death from all causes (HR: 0.96; 95% CI: 0.94, 0.98), CVD (HR: 0.96; 95% CI: 0.93, 0.99), IHD (HR: 0.96; 95% CI: 0.91, 1.00), and AMI (HR: 0.96, 95% CI: 0.91, 1.01). CONCLUSIONS: In this cohort with a generally high consumption of predominantly boiled potatoes, we find modest, inverse associations between potato consumption and death from all causes, CVD, and IHD.

Surviving the Potato Stems: Differences in Genes Required for Fitness by Dickeya dadantii and Dickeya dianthicola.

Bacteria belonging to the genus Dickeya cause blackleg and soft rot symptoms on many plant hosts, including potato. Although there is considerable knowledge about the genetic determinants that allow Dickeya to colonize host plants, as well as the genes that contribute to virulence, much is still unknown. To identify the genes important for fitness in potato stems, we constructed and evaluated randomly barcoded transposon mutant (RB-TnSeq) libraries of Dickeya dadantii and Dickeya dianthicola. We identified 169 and 157 genes important for growth in D. dadantii and D. dianthicola in stems, respectively. This included genes related to metabolic pathways, chemotaxis and motility, transcriptional regulation, transport across membranes, membrane biogenesis, detoxification mechanisms, and virulence-related genes, including a potential virulence cluster srfABC, c-di-GMP modulating genes, and pectin degradation genes. When we compared the results of the stem assay with other datasets, we identified genes important for growth in stems versus tubers and in vitro conditions. Additionally, our data showed differences in fitness determinants for D. dadantii and D. dianthicola. These data provide important insights into the mechanisms used by Dickeya when interacting with and colonizing plants and thus might provide targets for management.

Application of vibrational and fluorescence spectroscopy to the compositional analysis of colored-flesh potatoes.

BACKGROUND: Determination of composition and physicochemical parameters of natural products requires dedicated, often laborious and expensive, analytical protocols. Different spectroscopic techniques, in conjunction with chemometrics, seem to have a considerable potential in direct analysis of raw plant material and foods, without any chemical treatment. RESULTS: Fluorescence spectroscopy and three vibrational spectroscopy techniques were applied to determine total polyphenol content, antioxidant activity and macronutrient levels in red- and purple-fleshed potato varieties. Excitation-emission matrix fluorescence, Fourier transform Raman, attenuated total reflection Fourier transform infrared and near-infrared spectra were recorded for the freeze-dried samples. Combining spectral data and the results of reference analyses, partial least squares regression models were constructed for each parameter studied. For polyphenols and antioxidant activity, quantification errors found for validation samples amounted to 3.74-5.04% and 4.75-6.35%, respectively, whereas macronutrient analysis gave errors in the 3.45-4.55%, 3.09-5.30% and 5.10-8.58% ranges for starch, protein and sugar determinations, respectively. CONCLUSION: The obtained results demonstrate that different spectroscopic techniques in combination with multivariate modeling allow simultaneous determination of various parameters of plant samples based on a single sample spectrum. They can effectively replace commonly used protocols of food product analysis requiring sample dissolving and extraction of the compounds of interest. © 2023 Society of Chemical Industry.

[Nutritional components of 5 potatoes in Anqing City in 2021].

OBJECTIVE: To analyze the nutrient composition and nutritional value evaluation of 5 potatoes in Anqing City. METHODS: According to the requirements of the Technical Manual for Food Composition Monitoring Projects, 5 types of potato samples were collected from Anqing City, Anhui Province. National standard detection method were used to determine the nutritional components such as water, ash, protein, fat, dietary fiber, sugar, minerals, vitamins, and amino acids in the samples. The index of nutritional quality(INQ) method was used to evaluate proteins, vitamins, and minerals, and the amino acid scoring standard mode(FAO/WHO mode) was used to evaluate the nutritional value of amino acids. RESULTS: Among the 5 types of potatoes, purple potato had the highest protein(2.3 g/100 g) and dietary fiber content(3.6 g/100 g). Sweet potato(red) had the highest carotene content(4003 µg/100 g), sweet potato(white) had the highest content of vitamin C(15.4 mg/100 g). Sugar in potatoes mainly existed in three forms: fructose, glucose, and sucrose; Purple potatoes had the highest levels of calcium(47 mg/100 g) and phosphorus(74 mg/100 g), respectively. Potatoes(white) had the highest content of potassium(401 mg/100 g), while sweet potatoes(red) had the highest content of magnesium(31 mg/100 g). Sodium(104.0 mg/100 g), iron(0.9 mg/100 g), copper(0.17 mg/100 g), and manganese(0.40 mg/100 g) had the highest content in sweet potatoes(white). The Na/K ratio range of the 5 potato varieties was 0.003-0.456, and the INQ of phosphorus, potassium, magnesium, copper, and manganese were greater than 1. The detection result of 5 potatoes all contain 18 amino acids, and aspartic acid was the highest. The amino acid score(AAS) was 0.29-1.35, and the ratio coefficient(RC) was 0.47-1.69. CONCLUSION: The 5 types of potatoes are rich in dietary fiber, vitamin C and minerals, and belong to the high potassium and low sodium type of food. Potatoes can meet the daily needs of the human body for phosphorus, potassium, magnesium copper, and manganese elements. Lysine is rich in content and can be used as a nutritional supplement for grains. The AAS score and RC are close to 1, and the AAS evaluation mode is closer to the human amino acid composition mode, which can meet the daily needs of the human body for this essential amino acid.

Identification of genes governing resistance to PCN (Globodera rostochiensis) through transcriptome analysis in Solanum tuberosum.

Potato cyst nematodes (PCNs) are major pests worldwide that affect potato production. The molecular changes happening in the roots upon PCN infection are still unknown. Identification of transcripts and genes governing PCN resistance will help in the development of resistant varieties. Hence, differential gene expression of compatible (Kufri Jyoti) and incompatible (JEX/A-267) potato genotypes was studied before (0 DAI) and after (10 DAI) inoculation of Globodera rostochiensis J2s through RNA sequencing (RNA-Seq). Total sequencing reads generated ranged between 33 and 37 million per sample, with a read mapping of 48-84% to the potato reference genome. In the infected roots of the resistant genotype JEX/A-267, 516 genes were downregulated, and 566 were upregulated. In comparison, in the susceptible genotype Kufri Jyoti, 316 and 554 genes were downregulated and upregulated, respectively. Genes encoding cell wall proteins, zinc finger protein, WRKY transcription factors, MYB transcription factors, disease resistance proteins, and pathogenesis-related proteins were found to be majorly involved in the incompatible reaction after PCN infection in the resistant genotype, JEX/A-267. Furthermore, RNA-Seq results were validated through quantitative real-time PCR (qRT-PCR), and it was observed that ATP, FLAVO, CYTO, and GP genes were upregulated at 5 DAI, which was subsequently downregulated at 10 DAI. The genes encoding ATP, FLAVO, LBR, and GP were present in > 1.5 fold before infection in JEX-A/267 and upregulated 7.9- to 27.6-fold after 5 DAI; subsequently, most of these genes were downregulated to 0.9- to 2.8-fold, except LBR, which was again upregulated to 44.4-fold at 10 DAI.

Biofortified Yellow-Fleshed Potatoes Provide More Absorbable Zinc than a Commonly Consumed Variety: A Randomized Trial Using Stable Isotopes in Women in the Peruvian Highlands.

BACKGROUND: Zinc-biofortified potatoes have considerable potential to reduce zinc deficiency because of their low levels of phytate, an inhibitor of zinc absorption, and their high consumption, especially in the Andean region of Peru. OBJECTIVES: The purpose of this study was to measure fractional and total zinc absorption from a test meal of biofortified compared with regular potatoes. METHODS: We undertook a single-blinded randomized crossover study (using 67Zn and 70Zn stable isotopes) in which 37 women consumed 500-g biofortified or regular potatoes twice a day. Urine samples were collected to determine fractional and total zinc absorption. RESULTS: The zinc content of the biofortified potato and regular potato was 0.48 (standard deviation [SD]: 0.02) and 0.32 (SD: 0.03) mg/100 g fresh weight, respectively. Mean fractional zinc absorption (FZA) from the biofortified potatoes was lower than from the regular potatoes, 20.8% (SD: 5.4%) and 25.5% (SD: 7.0%), respectively (P < 0.01). However, total zinc absorbed was significantly higher (0.49; SD: 0.13 and 0.40; SD: 0.11 mg/500 g, P < 0.01, respectively). CONCLUSIONS: The results of this study demonstrate that biofortified potatoes provide more absorbable zinc than regular potatoes. Zinc-biofortified potatoes could contribute toward reducing zinc deficiency in populations where potatoes are a staple food. This trial was registered at clinicaltrials.gov as NCT05154500.

In vitro genotoxicity assessment of French fries from mass catering companies: a preliminary study.

It is generally assumed that French fries are likely to have weak in vitro mutagenic activity, but most studies thereof have only assessed gene mutations. In this article, the genotoxicity of 10 extracts of French fries was assessed using the in vitro micronucleus test (following the principles of the OECD 487 guidelines). Each sample was obtained from a different mass catering company in Navarra (Spain). This assay, together with the Ames test, is recommended in the basic in vitro phase included in the European Food Safety Authority Opinion on Genotoxicity Testing Strategies Applicable to Food and Feed Safety Assessment. Eight of 10 samples from mass catering companies induced chromosomal aberrations in the in vitro micronucleus test. Moreover, French fries deep-fried in the laboratory for different periods of time (0, 3, 5, 10, 20, 30 min) were assessed using the in vitro micronucleus test. Genotoxicity was observed in all time periods from 3 min on. The biological relevance of these results must be further explored.

Prospective cohort study on potato intake and mortality from cardiovascular diseases: the Japan Collaborative Cohort Study (JACC study).

PURPOSE: The association between potato intake and risk of cardiovascular diseases is unknown. This study aimed to examine the association between potatoes intake and mortality from stroke and coronary heart disease among Japanese. METHODS: The study included 74,750 participants of the Japan Collaborative Cohort Study, aged 40-79, who were initially free of cardiovascular diseases or cancer at baseline (1988-1990) and provided information on their potato intake. Hazard ratios and 95% confidence intervals were estimated by fitting a Cox proportional hazards model according to the frequency of potatoes intake (0, 0.4, 1.5, 3.5 and 7 servings per week) adjusting for geographic location, age, body mass index, drinking status, smoking status, perceived mental stress, education level, walking time, dietary intakes of total energy, meat, fish, vegetables, fruit, dairy products, cakes, and salt. RESULTS: Over a median of 19.2 years of follow-up, 4908 deaths from cardiovascular diseases were identified: 1019 from coronary heart diseases and 2153 from strokes (738 ischemic strokes and 495 hemorrhagic strokes). After adjustment for potential confounding factors, the hazard ratio of mortality from cardiovascular diseases for daily potato intake compared with no potato intake was 0.82 (95% confidence interval: 0.70, 0.95) among women, and 1.01 (0.88, 1.16) among men. Among women, the multivariable hazard ratios were 0.67 (0.48, 0.96) for coronary heart disease, 0.83 (0.66-1.05) for total stroke, 0.70 (0.43-1.15) for hemorrhagic stroke, and 0.75 (0.49-1.13) for ischemic stroke. CONCLUSION: We found an inverse association of potato intake with mortality from total cardiovascular diseases, especially that from coronary heart disease, among Japanese women. To our knowledge, this is the first report to show an inverse association between potato intake and total cardiovascular diseases.

Effect of Silicon on Micronutrient Content in New Potato Tubers.

Since silicon can improve nutrient uptake in plants, the effect of foliar silicon (sodium metasilicate) application on micronutrient content in early crop potato tuber was investigated. Silicon was applied at dosages of 23.25 g Si∙ha-1 or 46.50 g Si∙ha-1 (0.25 L∙ha-1 or 0.50 L∙ha-1 of Optysil) once at the leaf development stage (BBCH 14-16), or at the tuber initiation stage (BBCH 40-1), and twice, at the leaf development and tuber initiation stages. Potatoes were harvested 75 days after planting (the end of June). Foliar-applied silicon reduced the Fe concentration and increased Cu and Mn concentrations in early crop potato tubers under water deficit conditions but did not affect the Zn, B, or Si concentrations. The dosage and time of silicon application slightly affected the Fe and Cu concentration in the tubers. Under drought conditions, the highest Mn content in the tuber was observed when 46.50 g Si∙ha-1 was applied at the leaf development stage, whereas under periodic water deficits, it was highest with the application of the same silicon dosage at the tuber initiation stage (BBCH 40-41). The Si content in tubers was negatively correlated with the Fe and B content, and positively correlated with the Cu and Mn content.

Peppermint essential oil volatiles as natural alternative to prevent potato sprouting induced by gibberellic acid.

The objective was to evaluate the effect of peppermint essential oil (PEO) on the inhibition of potato sprouting induced by gibberellic acid (GA) during storage. PEO (0.08 and 0.15 mL L-1) was applied in the presence and absence of gibberellic acid (10 mg L-1). The presence of phytopathogens and changes in breaking of dormancy, weight loss, moisture content, and total soluble solids were measured during 28 days. The inhibition of potato sprouting by the PEO occurred at the lowest concentration, even in the presence of GA. Sprout development was inhibited with PEO addition, delaying the dormancy break and reducing weight loss. However, potato sprouting was still inhibited after the removal of the PEO, evidencing its residual efficacy. PEO application at both concentrations had a satisfactory effect on sprout suppression and can be used as a promising eco-friendly approach for inhibiting the sprouting of potato tubers during storage.

Potato consumption is not associated with elevated cardiometabolic risk in adolescent girls.

We examined the association between potato consumption in two different age periods during adolescence and risk of obesity and cardiometabolic dysfunction in White and Black girls. We used data from the biracial prospective National Growth and Health Study. Average potato consumption was derived from multiple 3-d food records in two age periods, 9-11 and 9-17 years, and included white and sweet potatoes from all sources. Multivariable logistic regression models were used to estimate OR for becoming overweight, developing prehypertension, elevated TAG levels or impaired fasting glucose (IFG) at 18-20 years of age according to the category of daily potato intake. We also stratified by cooking method (fried/non-fried) and race. ANCOVA was also used to estimate adjusted mean levels of BMI, systolic blood pressure, diastolic blood pressure, log-transformed TAG, the TAG:HDL ratio and fasting glucose levels associated with potato intake category. Higher potato consumption was associated with higher fruit and non-starchy vegetable intakes and higher Healthy Eating Index scores in Black girls. There were no statistically significant associations overall between moderate or higher (v. lower) intakes of potatoes and risks of overweight, prehypertension, elevated fasting TAG, high TAG:HDL ratio or IFG. Also, no adverse associations were found between fried or non-fried potato intake and cardiometabolic outcomes. Potato consumption has been the subject of much controversy in recent years. This study adds evidence that potato consumption among healthy girls during the critical period of adolescence was not associated with cardiometabolic risk.

Contamination of home-grown and retail vegetables with Clostridioidesdifficile.

The opportunistic intestinal pathogen Clostridioides difficile is the number one cause of nosocomial diarrhea in humans. In this study, C. difficile was isolated from 26.7% of potatoes and 1.9% of salads from German retail. The majority of strains possessed toxinogenic PCR-ribotypes that are associated with human clinical cases pointing towards a potential risk to human health.

Identifying Irregular Potatoes Using Hausdorff Distance and Intersection over Union.

Further processing and the added value of potatoes are limited by irregular potatoes. An ellipse-fitting-based Hausdorff distance and intersection over union (IoU) method for identifying irregular potatoes is proposed to solve the problem. First, the acquired potato image is resized, translated, segmented, and filtered to obtain the potato contour information. Secondly, a least-squares fitting method fits the extracted contour to an ellipse. Then, the similarity between the irregular potato contour and the fitted ellipse is characterized using the perimeter ratio, area ratio, Hausdorff distance, and IoU. Next, the characterization ability of the four features is analyzed, and an identification standard of irregular potatoes is established. Finally, we discuss the algorithm's shortcomings in this paper and draw the advantages of the algorithm by comparison. The experimental results showed that the characterization ability of perimeter ratio and area ratio was inferior to that of Hausdorff distance and IoU, and using Hausdorff distance and IoU as feature parameters can effectively identify irregular potatoes. Using Hausdorff distance separately as a feature parameter, the algorithm achieved excellent performance, with precision, recall, and F1 scores reaching 0.9423, 0.98, and 0.9608, respectively. Using IoU separately as a feature parameter, the algorithm achieved a higher overall recognition rate, with precision, recall, and F1 scores of 1, 0.96, and 0.9796, respectively. Compared with existing studies, the proposed algorithm identifies irregular potatoes using only one feature, avoiding the complexity of high-dimensional features and significantly reducing the computing effort. Moreover, simple threshold segmentation does not require data training and saves algorithm execution time.

Volatile Organic Compounds and Physiological Parameters as Markers of Potato (Solanum tuberosum L.) Infection with Phytopathogens.

The feasibility of early disease detection in potato seeds storage monitoring of volatile organic compounds (VOCs) and plant physiological markers was evaluated using 10 fungal and bacterial pathogens of potato in laboratory-scale experiments. Data analysis of HS-SPME-GC-MS revealed 130 compounds released from infected potatoes, including sesquiterpenes, dimethyl disulfide, 1,2,4-trimethylbenzene, 2,6,11-trimethyldodecane, benzothiazole, 3-octanol, and 2-butanol, which may have been associated with the activity of Fusarium sambucinum, Alternaria tenuissima and Pectobacterium carotovorum. In turn, acetic acid was detected in all infected samples. The criteria of selection for volatiles for possible use as incipient disease indicators were discussed in terms of potato physiology. The established physiological markers proved to demonstrate a negative effect of phytopathogens infecting seed potatoes not only on the kinetics of stem and root growth and the development of the entire root system, but also on gas exchange, chlorophyll content in leaves, and yield. The negative effect of phytopathogens on plant growth was dependent on the time of planting after infection. The research also showed different usefulness of VOCs and physiological markers as the indicators of the toxic effect of inoculated phytopathogens at different stages of plant development and their individual organs.

Natural abundance analysis of the role played by 15 N as indicator for the certification of organic-system deriving food.

BACKGROUND: The natural abundance of stable isotope 15 N (δ15 N) in production systems has emerged as an alternative to distinguish organic products from conventional ones. This study evaluated the use of δ15 N values recorded for nitrogen fertilizers, soil and plant tissue in order to set the differences between organic and conventional agricultural production systems applied to rice, potatoes, apple and banana crops. RESULTS: Values of δ15 N recorded for N sources ranged from +5.58‰ to +18.27‰ and from -3.55‰ to +3.19‰ in organic and synthetic fertilizers, respectively. Values recorded for δ15 N in food from organic rice, potatoes and banana farms were higher than values recorded for δ15 N in conventional farms; the same was observed for values recorded for δ15 N in leaves from the four crops. CONCLUSION: Results have allowed for differentiation between production systems due to values of δ15 N recorded in leaves of all crops and food, for rice, potatoes and banana trees. © 2021 Society of Chemical Industry.

Replacement of potatoes with other vegetables and risk of myocardial infarction in the Danish Diet, Cancer and Health cohort.

Intake of vegetables is recommended for the prevention of myocardial infarction (MI). However, vegetables make up a heterogeneous group, and subgroups of vegetables may be differentially associated with MI. The aim of this study was to examine replacement of potatoes with other vegetables or subgroups of other vegetables and the risk of MI. Substitutions between subgroups of other vegetables and risk of MI were also investigated. We followed 29 142 women and 26 029 men aged 50-64 years in the Danish Diet, Cancer and Health cohort. Diet was assessed at baseline by using a detailed validated FFQ. Hazard ratios (HR) with 95 % CI for the incidence of MI were calculated using Cox proportional hazards regression. During 13·6 years of follow-up, 656 female and 1694 male cases were identified. Among women, the adjusted HR for MI was 1·02 (95 % CI 0·93, 1·13) per 500 g/week replacement of potatoes with other vegetables. For vegetable subgroups, the HR was 0·93 (95 % CI 0·77, 1·13) for replacement of potatoes with fruiting vegetables and 0·91 (95 % CI 0·77, 1·07) for replacement of potatoes with other root vegetables. A higher intake of cabbage replacing other vegetable subgroups was associated with a statistically non-significant higher risk of MI. A similar pattern of associations was found when intake was expressed in kcal/week. Among men, the pattern of associations was overall found to be similar to that for women. This study supports food-based dietary guidelines recommending to consume a variety of vegetables from all subgroups.

Substitutions between potatoes and other vegetables and risk of ischemic stroke.

PURPOSE: Intake of vegetables has been associated with a lower risk of ischemic stroke in observational studies controlling for total energy intake. However, adjustment for energy intake introduces a substitution aspect, which affects the interpretation of the results. We investigated replacement of potatoes with other vegetables, substitutions between vegetable subgroups, and risk of ischemic stroke and ischemic stroke subtypes. METHODS: The Danish Diet, Cancer and Health cohort included 57,053 participants aged 50-64 years at recruitment in 1993-1997. Diet was assessed from a validated 192-item semi-quantitative food frequency questionnaire. We calculated hazard ratios (HR) with 95% confidence intervals (CI) for the incidence of ischemic stroke using Cox proportional hazard regression. RESULTS: During 13.5 years of follow-up, 1879 cases of ischemic stroke were identified including 319 cases of large-artery atherosclerosis and 844 cases of small-vessel occlusion. The adjusted HR for total ischemic stroke associated with food substitutions of equal amounts (500 g/week) was 0.86 (95% CI 0.76, 0.97) for replacement of potatoes with fruiting vegetables and 0.92 (95% CI 0.84, 1.02) for replacement of potatoes with other root vegetables. The HR for replacing potatoes with the sum of other vegetables was 0.95 (95% CI 0.90, 1.00). Substitution of cabbage for either potatoes, fruiting vegetables or other root vegetables was associated with a statistically non-significant higher risk of ischemic stroke. The patterns of associations were similar for ischemic stroke subtypes and for equivalent substitutions using isocaloric amounts. CONCLUSION: Replacing potatoes with fruiting vegetables was associated with a lower risk of ischemic stroke.

Screening of Wild Potatoes Identifies New Sources of Late Blight Resistance.

Late blight (LB) of potato is considered one of the most devastating plant diseases in the world. Most cultivated potatoes are susceptible to this disease. However, wild relatives of potatoes are an excellent source of LB resistance. We screened 384 accessions of 72 different wild potato species available from the U.S. Potato GeneBank against the LB pathogen Phytophthora infestans in a detached leaf assay (DLA). P. infestans isolates US-23 and NL13316 were used in the DLA to screen the accessions. Although all plants in 273 accessions were susceptible, all screened plants in 39 accessions were resistant. Resistant and susceptible plants were found in 33 accessions. All tested plants showed a partial resistance phenotype in two accessions, segregation of resistant and partial resistant plants in nine accessions, segregation of partially resistant and susceptible plants in four accessions, and segregation of resistant, partially resistant, and susceptible individuals in 24 accessions. We found several species that were never before reported to be resistant to LB: Solanum albornozii, S. agrimoniifolium, S. chomatophilum, S. ehrenbergii, S. hypacrarthrum, S. iopetalum, S. palustre, S. piurae, S. morelliforme, S. neocardenasii, S. trifidum, and S. stipuloideum. These new species could provide novel sources of LB resistance. P. infestans clonal lineage-specific screening of selected species was conducted to identify the presence of RB resistance. We found LB resistant accessions in Solanum verrucosum, Solanum stoloniferum, and S. morelliforme that were susceptible to the RB overcoming isolate NL13316, indicating the presence of RB-like resistance in these species.