Made available in DSpace on 2016-01-26T18:56:22Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 249370 bytes, checksum: bb3ab2f95decedaeb7a114dc63aae796 (MD5) Previous issue date: 2011-01-25 / The production cost of new areas in the cerrado presents high values due to larger amount of farming operations when compared to conventional crops. The cerrado soils have low natural fertility and require large quantities of limestone for its correction significantly increasing the cost of production. The objective this study was to evaluate whether the Boro when applied in the cultivation of upland rice with low technological level, increases the productivity rice. The field work was conducted in the municipality of Nova Xavantina - MT in 2009/10 in two areas (first and second year of production). We used six treatments of boron in the source of boric acid (17 % of B), with doses of 0, 0.5, 1.0, 1.5, 2.0, and 2.5 kg B per ha. The plots were 10 m long and 3.4 m wide with 20-sowing rows, with spaced at 0.17 m. The fertilization of 160 kg of 08-28-16 fertilizer was formulated according to the results of soil analysis and used the cultivar BRS Sertaneja in amount of 115 kg of seeds per ha. Among the variables analyzed the productivity in the area of the first year was influenced by boron fertilization, whre the treatment that used a dose of 2.5 kg B hit productivity of 2.677 kg/ha-1. The cost analysis positive for both areas, where in the area of the first year, the cost benefit of boron fertilization was R$169,44 (with a dose of 1 kg B/ha). As for the second year the area of greatest cost benefit was obtained with a dose of 2.5 kg B, which resulted in na increase in productivity of 11.80 bags (60 kg) and therefore a cost benefit of R$333.83 per hectare. The use of boron into new areas of cerrado compensated the low technological level that was used in the formation of the crops, providing positive results in the cost benefit of the crop without significant increases inproduction costs. / O custo de produção de áreas novas no cerrado apresenta valores elevados devido á maior quantidade de operações agrícolas, quando comparado a lavouras convencionais. Os solos do cerrado apresentam baixa fertilidade natural e exigem grandes quantidades de calcário para sua correção, aumentando significamente o custo de produção. O objetivo deste trabalho foi avaliar se o Boro quando aplicado na cultura do arroz de terras altas com baixo nível tecnológico, proporcionaria um ganho de produtividade na cultura do arroz. O trabalho foi conduzido a campo no município de Nova Xavantina MT na safra 2009/10 em duas áreas (primeiro e segundo ano de produção). Foram utilizados 6 tratamentos de boro na fonte de ácido bórico (17% de B), sendo as doses de: 0; 0,5; 1,0; 1,5; 2,0; e 2,5 kg de B por ha. As parcelas tiveram 10 m de comprimento por 3,4 m de largura com 20 linhas de plantio no espaçamento de 0,17 m. A adubação de 160 kg do adubo formulado 08-28-16 foi em função dos resultados da análise do solo e utilizou-se a cultivar BRS Sertaneja na quantidade de 115 kg de sementes por ha. Dentre as variáveis avaliadas a produtividade da área de primeiro ano foi influenciada pela adubação boratada, onde o tratamento que utilizou a dose de 2,5 kg de B atingiu a produtividade de 2.677 kg/ha-1. A análise de custo foi positiva para as duas áreas, onde na área de primeiro ano, o custo beneficio da adubação boratada foi de R$169,44 (com a dose de 1 kg B/ha). Já para a área de segundo ano o maior custo beneficio foi obtido com a dose de 2,5 kg de B, que proporcionou um aumento na produtividade de 11,80 sacas (60 kg) e conseqüentemente um custo beneficio de R$333,83 por hectare. O uso do boro em áreas novas do cerrado compensou o baixo nível tecnológico que foi empregado na formação das lavouras, proporcionando resultados positivos no custo beneficio da lavoura sem acréscimos significativos no custo de produção.

Made available in DSpace on 2016-07-18T17:51:06Z (GMT). No. of bitstreams: 1 Dissertacao.pdf: 249370 bytes, checksum: bb3ab2f95decedaeb7a114dc63aae796 (MD5) Previous issue date: 2011-01-25 / The production cost of new areas in the cerrado presents high values due to larger amount of farming operations when compared to conventional crops. The cerrado soils have low natural fertility and require large quantities of limestone for its correction significantly increasing the cost of production. The objective this study was to evaluate whether the Boro when applied in the cultivation of upland rice with low technological level, increases the productivity rice. The field work was conducted in the municipality of Nova Xavantina - MT in 2009/10 in two areas (first and second year of production). We used six treatments of boron in the source of boric acid (17 % of B), with doses of 0, 0.5, 1.0, 1.5, 2.0, and 2.5 kg B per ha. The plots were 10 m long and 3.4 m wide with 20-sowing rows, with spaced at 0.17 m. The fertilization of 160 kg of 08-28-16 fertilizer was formulated according to the results of soil analysis and used the cultivar BRS Sertaneja in amount of 115 kg of seeds per ha. Among the variables analyzed the productivity in the area of the first year was influenced by boron fertilization, whre the treatment that used a dose of 2.5 kg B hit productivity of 2.677 kg/ha-1. The cost analysis positive for both areas, where in the area of the first year, the cost benefit of boron fertilization was R$169,44 (with a dose of 1 kg B/ha). As for the second year the area of greatest cost benefit was obtained with a dose of 2.5 kg B, which resulted in na increase in productivity of 11.80 bags (60 kg) and therefore a cost benefit of R$333.83 per hectare. The use of boron into new areas of cerrado compensated the low technological level that was used in the formation of the crops, providing positive results in the cost benefit of the crop without significant increases inproduction costs. / O custo de produção de áreas novas no cerrado apresenta valores elevados devido á maior quantidade de operações agrícolas, quando comparado a lavouras convencionais. Os solos do cerrado apresentam baixa fertilidade natural e exigem grandes quantidades de calcário para sua correção, aumentando significamente o custo de produção. O objetivo deste trabalho foi avaliar se o Boro quando aplicado na cultura do arroz de terras altas com baixo nível tecnológico, proporcionaria um ganho de produtividade na cultura do arroz. O trabalho foi conduzido a campo no município de Nova Xavantina MT na safra 2009/10 em duas áreas (primeiro e segundo ano de produção). Foram utilizados 6 tratamentos de boro na fonte de ácido bórico (17% de B), sendo as doses de: 0; 0,5; 1,0; 1,5; 2,0; e 2,5 kg de B por ha. As parcelas tiveram 10 m de comprimento por 3,4 m de largura com 20 linhas de plantio no espaçamento de 0,17 m. A adubação de 160 kg do adubo formulado 08-28-16 foi em função dos resultados da análise do solo e utilizou-se a cultivar BRS Sertaneja na quantidade de 115 kg de sementes por ha. Dentre as variáveis avaliadas a produtividade da área de primeiro ano foi influenciada pela adubação boratada, onde o tratamento que utilizou a dose de 2,5 kg de B atingiu a produtividade de 2.677 kg/ha-1. A análise de custo foi positiva para as duas áreas, onde na área de primeiro ano, o custo beneficio da adubação boratada foi de R$169,44 (com a dose de 1 kg B/ha). Já para a área de segundo ano o maior custo beneficio foi obtido com a dose de 2,5 kg de B, que proporcionou um aumento na produtividade de 11,80 sacas (60 kg) e conseqüentemente um custo beneficio de R$333,83 por hectare. O uso do boro em áreas novas do cerrado compensou o baixo nível tecnológico que foi empregado na formação das lavouras, proporcionando resultados positivos no custo beneficio da lavoura sem acréscimos significativos no custo de produção.

La dénutrition est responsable de dommages à long terme sur le développement physique et cognitif et de la moitié des décès chez les enfants de moins de 5 ans. La majorité des interventions est concentrée sur la nutrition des jeunes enfants et des mères. Cependant, la malnutrition, également prévalente chez les enfants plus âgés et les adolescents, notamment en Afrique et en Asie du Sud-Est, a des conséquences sur leur développement global, en raison des besoins élevés en énergie, protéines et micronutriments induits par les pics de croissance et de développement cérébral durant ces périodes de la vie. Nos travaux ont évalué la prévalence des malnutritions et leurs facteurs déterminants chez des enfants d’âge scolaire et des adolescents au Sénégal et au Cambodge, ainsi que l’efficacité d’une intervention avec une alimentation enrichie en micronutriments en milieu scolaire au Cambodge. Une étude transversale fut conduite sur un échantillon représentatif de 600 enfants des écoles primaires publiques de la région de Dakar sélectionnés par un échantillonnage aléatoire en grappes. Des taux élevés de maigreur (19%) et de carences en micronutriments (fer 39%, iode 33%, zinc 26%) ont été démontrés. L’enquête de consommation alimentaire a révélé des apports en micronutriments et en énergie insuffisants, ainsi qu’une contribution à l’apport énergétique déficitaire pour les protéines et en excédent pour les lipides, révélant des conditions précaires de ces scolaires en milieu urbain au Sénégal. Au Cambodge, un essai contrôlé randomisé en grappes en double aveugle conduit sur 2400 enfants a permis de mesurer l’impact de riz enrichis en micronutriments consommés pendant 6 mois, dans le cadre du programme d’alimentation scolaire du PAM, sur leurs statuts en micronutriments et leurs performances cognitives. Avant l’intervention, les faibles performances cognitives étaient associées au retard de croissance, à la carence en fer et aux infections parasitaires. La croissance était positivement associée au statut en zinc, lui-même négativement associé à l’infection parasitaire. Les riz enrichis en vitamine A ont amélioré le statut en vitamine A et le riz avec la concentration en fer la plus élevée a eu un impact positif sur les performances cognitives. Les données du Sénégal et du Cambodge ont été analysées pour étudier les indicateurs de malnutrition chez ces enfants d’âge scolaire et adolescents. Comme recommandé par l’OMS, nous avons déterminé les valeurs seuils du périmètre brachial pour détecter la malnutrition aigüe chez les enfants de plus de 5 ans au Cambodge. Nous avons confirmé la nécessité de corriger les concentrations plasmatiques de RBP et de ferritine en fonction du statut inflammatoire et démontré l’intérêt d’une telle correction pour les récepteurs de la transferrine pour améliorer l’estimation de la prévalence des carences en vitamine A et en fer dans ces populations ou l’inflammation est endémique. La dénutrition reste un problème de santé publique chez les enfants d’âge scolaire et les adolescents au Sénégal et Cambodge. La détermination des malnutritions dans cette tranche d’âge pourrait être améliorée par des recherches sur les indicateurs prenant en compte la variabilité intra populations, les facteurs environnementaux et les besoins spécifiques de ces populations. Des interventions scolaires comme au Cambodge ont des effets positifs sur la nutrition et le développement, plaidant en faveur d’une extension des programmes d’alimentation scolaire y compris dans les zones urbaines défavorisées. La distribution d’aliments fortifiés dans les cantines scolaires existantes est une stratégie peu couteuse d’amélioration de la nutrition et de la santé. La nutrition des adolescentes requiert une attention particulière en raison du risque de grossesse précoce élevé dans de nombreux pays du Sud. / Undernutrition causes long-term damages on the physical and cognitive development and half of deaths among children under 5 y. Most of the current interventions are concentrated on improving nutrition among young children and mothers. However, malnutrition is also prevalent among older children and adolescents, especially in Africa and in South-East Asia. It has adverse effects on their global development because of the high requirements in energy, protein and micronutrients resulting from growth and brain development spurts occurring these periods of life. Our research evaluated the prevalence of malnutrition and their determinants factors among school-aged children and adolescents in Senegal and Cambodia, as well as the effectiveness of micronutrient fortified food in schools in Cambodia. A cross-sectional study was conducted on a representative sample of ~ 600 children aged from 5 to 17 years from primary state schools of Dakar area, selected through a two-stage random cluster sample (30 schools × 20 children). Elevated rates of thinness (19%) and micronutrient deficiencies (iron 39%, iodine 33%, zinc 26%) were showed. The food consumption survey revealed insufficient micronutrients and energy intake, as well as contribution to total energy intake insufficient in proteins and excessive in lipids, which reveals poor conditions among school children in Senegal. In Cambodia, a cluster-randomized placebo-controlled double-blind trial was conducted among 2400 children aged 6-16 y to measure the impact of fortified rice consumed during 6 months within the school feeding program of WFP on their micronutrient status and cognitive performance. Before the intervention, poor cognitive performance was associated to stunting, iron deficiency and parasite infestation. The growth was positively associated to zinc status, which was negatively associated to parasite infestation. Rice fortified with vitamin A improved vitamin A status and rice with the highest iron concentration had a positive impact on cognitive performance. Data from Senegal and Cambodia were analyzed to study indicators of malnutrition among school-aged children and adolescents. According to the WHO recommendations, we suggested mid-upper-arm circumference (MUAC) cut-offs to screen for acute malnutrition among children above 5 years in Cambodia (15.5 cm, 16.4 cm and 18.2cm in boys and 15.4 cm, 16.6 cm and 17.9 cm in girls aged 5-7.9y, 8-11.9 y, and 11-13.9 y). We confirmed the need to correct plasma concentrations of retinol-binding-protein and ferritin according to inflammatory status, and showed the interest of a similar correction for transferrin receptor, these corrections improving the estimation of prevalence of vitamin A and iron deficiencies in populations where inflammation is endemic. Undernutrition remains a public health issue among school-aged children and adolescents in Senegal and Cambodia. Determination of malnutrition in this age range could be improved by research on indicators taking into account intra variability populations, environmental factors and specific needs of these populations. School-based interventions like the one in Cambodia have positive effects on nutrition and development of children, advocating for extension of school feeding, including in disadvantaged urban areas. Distribution fortified food in existing school canteens is a cost-effective strategy to improve nutrition and health. More research and efforts should be shifted to the nutritional status of adolescent girls because of the risk of early childbearing, still commonly practiced in developing countries, and the importance of adequate nutrition during pregnancy. Investing in nutrition in this age range is an opportunity to consolidate the progress achieved in pregnant women and young children through a life-cycle approach and to optimize the development of next generations in developing countries.

Thesis (M. Sc. Agriculture (Soil Science)) -- University of Limpopo, 2019 / One of the major constraints to crop productivity in South Africa is crop nutrient deficiency especially micronutrients. Laboratory, glasshouse and field studies were carried out during the 2016/2017 growing season to assess the effects of micronutrient (Zn, B and Mo) seed priming on maize growth and yield in micronutrient deficient soils of the Limpopo province. The laboratory experiment was carried out in a completely randomized design (CRD) laid out in a 3 x 5 x 3 factorial treatment structure with three replications. The assessments of the micronutrients were made at 0%, 0.01%, 0.05%, 0.1%, and 0.5% concentrations. The seeds were primed in the solutions for 24 h, 12 h and 8 h. The glasshouse experiment was carried out in a completely randomized design (CRD) laid out in a 3 x 4 x 2 factorial treatment structure with three replications. In the field, a single factor experiment in a randomised complete block design (RCBD) with three replications and a control was used, with micronutrient concentrations as levels. The laboratory study investigated the effect of seed priming with Zn, Mo and B on germination (germination percentage (GP), germination rate (GR), the coefficient velocity of germination (CVG), days to germination (DG) and mean germination time (MGT)). The interaction between seed priming duration and concentration levels of seeds primed with B had significant effect (P < 0.05) on germination. The interaction between seed priming duration and concentration levels of seeds primed with Zn had significant effect (P < 0.05) on germination. The interaction between seed priming duration and Mo concentration levels on CVG, MGT and DE had no significant different (P > 0.05). Meanwhile, the effect on GP and GR had significant (P < 0.05) effects. Seed priming with the micronutrients and water resulted in improved GP, MGT and CVG for seeds primed with 0.01, 0.05 and 0.1% for 24 h in laboratory conditions. The glasshouse study was established to investigate the effect micronutrient seed priming on seedling establishment and growth. The effects of the interaction between Mo concentration levels and duration, Zn concentration levels and duration, B concentration levels and duration and control had no significant (P > 0.05) effect on days to emergence (DE), seedling wet weight (WW), dry weight (DW), chlorophyll, stem diameter, plant height and final root length (RL). Furthermore, seeds primed at lower concentration levels (0.05, 0.01 and 0.1%) with longer duration priming period (24 hours) for Mo, Zn and B recorded higher results on the seedling emergence and establishment parameters. The field investigation showed that priming with micronutrients solutions had no significant difference on the final values of dry biomass, prolificacy, harvest index and grain yield. Seeds primed with 0.05, 0.01 and 0.1 % concentration levels with longer duration priming period (24 hours) showed improvement in germination and seedling establishment. The grain yield and grain nutrient content was not improved, meanwhile emergence was improved. This confirms that not only micronutrients limit yields maximization and crop nutrients content retention solely, rather that the complexity of the agricultural crop production environment should be well understood by all farmers to archive their goals. Keywords: Boron, Maize, Micronutrients, Molybdenum, Nutrient seed priming, Zinc. / National Research Foundation (NRF)

The adequate intake of micronutrients is important to maintain optimal health and prevent nutritional disorders and chronic disease. Studies have shown that medical students often reduce self-care behaviors and lack adequate dietary intake, leading to nutritional deficiencies. In this quantitative cross-sectional study, measurements of micronutrient levels in a sample of allied health and nursing students were compared to Recommended Daily Allowance (RDA) values. NutritionQuest Data-on-Demand System was used to analyze nutrients and food group intake. The postpositivist paradigm was used to examine how the independent and dependent variables relate to each other. Using a one-sample t test, a comparison of average micronutrient intake among study participants with RDA values for those micronutrients showed that average micronutrient intake in the study population was higher than recommended values. Two sample t-test results showed no significant difference in average intake of micronutrients among participants with high and low income levels, or with high and low stress levels. As the normality assumption was not satisfied by the outcome variables, nonparametric tests were used to evaluate hypotheses. While this finding does not support the original hypothesis, it could have implications for the role of allied health and nursing practitioners in the care of both their patients and members of their medical team. Conversely, an assumption of this study was that a high level of similarity between the traditional medical student population and the allied health and nursing population in terms of nutritional habits may have led to a flaw in the overall research hypothesis. The detection of micronutrient deficiencies in students can bring awareness to improve nutritional intake and initiate a change in how public health officials advocate healthy and balanced diets.

This thesis focuse on bariatric-metabolic surgery and its impact on serum concentrations of various metabolic parameters. The thesis is divided into two parts - theoretical and practical. Basic facts about bariatric-metabolic surgery such as its history, indications, contraindications, surgical methods and their results, nutrition after surgery and the frequency of micronutrient's deficits are described in the theoretical part. Furthermore, information about calcium-phosphate metabolism and metabolites such as calcium, phosphorus, magnesium, vitamin D, vitamin K, parathyroid hormone and osteomarkers is also included. The influence of nutrition and nutritional status on the quality of bone tissue is also mentioned. Last section of the theoretical part is focused on the important vitamins and minerals. The practical part discusses measurements of selected metabolites in serum before and half a year after the surgery. Results of questionnaires which were given to respondents are also included. Questionnaires were focused on lifestyle, nutrition, physical activities and whether the patients take some supplements of micronutrients and protein concentrates. The goal of this work is to evaluate the effect of the surgery on serum concentrations of metabolic parameters and their effect on the health and...

Background: Multiple micronutrient deficiencies are prevalent in pregnant women in developing countries and can result in adverse effects to both the mother and infant. Multiple micronutrient supplements or supplementary foods may be a way to combat micronutrient deficiencies. Objective: To assess change in micronutrient and protein levels in moderately malnourished pregnant Malawian women after receiving one of three nutritional interventions. Methods: Serum retinol, 25-hydroxyvitamin D, ferritin, vitamin B12, folate, zinc, albumin and C-reactive protein concentrations were measured in pregnant women with MUAC >20.6 cm and Results: Baseline micronutrient concentrations indicated high rates of deficiency in zinc (29-39%) and albumin (37-46%), and marginal status of retinol (26-37%) and vitamin D (31-32%). Adjusted mean changes in vitamin B12 concentrations from week 0 to week 10 were -17.1, -36.1, and -52.9 pg/mL for RUSF, CSB-UNIMMAP, and CSB-IFA, respectively (p=0.007). Adjusted mean changes in vitamin D concentrations from week 0 to week 10 were 6.1, 3.1, and 1.7 ng/mL for RUSF, CSB-UNIMMAP, and CSB-IFA, respectively (p=0.007). Adjusted mean changes in folate concentrations from week 0 to week 10 were 2.2, 1.7, and 4.0 ng/mL for RUSF, CSB-UNIMMAP, and CSB-IFA, respectively (p=0.37 for effect of treatment; p=0.06 for the interaction effect of time*treatment). Changes in ferritin, zinc, albumin, retinol, and CRP were not significantly different between treatment groups. Conclusions: Deficiencies in zinc and albumin, and marginal status of vitamin D and retinol, are common among this population of moderately malnourished pregnant Malawian women. Significant changes in vitamin D and vitamin B12were observed from week 0 to week 10, with the RUSF group having the greatest improvements compared to the CSB-UNIMMAP and CSB-IFA treatments.

Premenstrual syndrome (PMS) is characterized by the presence of physical and psychological symptoms restricted to the late luteal phase of the menstrual cycle and associated with substantial impairment in life activities. In the U.S. about 8 to 15% of women of reproductive age suffer from PMS. Many micronutrients are potentially involved in the development of this disorder due to their role in the synthesis of neurotransmitters and hormones or in their regulation, but few previous studies have evaluated the effects of micronutrients on PMS. The first study examined the association between B vitamin intakes, and PMS development among women participating in the Nurses' Health Study 2 (NHS2). We found that high thiamin and high riboflavin intake from food sources were associated with lower risk of PMS. There were not significant associations between niacin, vitamin B6, folate, and vitamin B12 dietary intake and incident PMS. Intakes of B vitamins from supplements were not associated with lower risk of PMS. The second study evaluated the association between selected mineral intakes and PMS development in the NHS2. In this study, high iron intakes were associated with lower risk of PMS. Although there was no association between zinc and PMS risk, high intake of zinc relative to copper was associated with lower risk of PMS. There were no associations between of magnesium, copper, and manganese intakes and PMS. We observed a significantly higher risk of PMS in women with high intakes of potassium from food sources. The third study focused on the association between dietary intakes of B vitamins, zinc, magnesium, iron, potassium, and sodium and some biomarkers and PMS prevalence among younger women. In this study, we found an association between zinc intake and lower prevalence of PMS. Each 1 mg/d increase in vitamin B6 from foods was associated with a lower PMS symptom score. Blood magnesium levels were higher in women with PMS compared to women without PMS. We observed that intakes of some micronutrients were associated with lower risk of PMS, but further studies should be conducted. This dissertation contributes to the research on modifiable risk factors for PMS.

The strength of leaf fibers and the nutritional value of the edible fruit of several yucca species native to the U.S. southwest were studied to aid in the determination of species best suited for commercial cultivation by the Navajo Nation. The leaves were softened in an autoclave to facilitate the removal of the leaf matrix, conditioned in environmentally controlled chambers, and the fibers were broken using a texture analyzer. The fibers were frozen and cross sectioned and photographed to determine cross sectional area. Official methods were used to determine the nutritional content of the fruit. The mean tensile strength of Y. angustissima, Y. baccata, and Y. glauca was 484 ±79, 710±174, and 388±104 MPa, respectively. Fibers from the leaves of Y. baccata had a significantly higher tensile strength than the leaves of the other two species. Nutritional profiling of the fruit of Y. angustissima and Y. baccata indicated that the fruit of both species are good sources of vitamin C (73-119 mg/100g) and thiamin (0.20 to 0.22 mg/100g). Because of its edible fruit and superior leaf fiber tensile strength, Y. baccata is recommended as the best species for cultivation and commercialization.

Fe biofortification of potato is a promising strategy to prevent Fe deficiency worldwide either through traditional breeding or biotechnological approaches. These approaches require the identification of candidate genes to uptake, transport and store Fe in potato tubers. We employed multiple approaches including SNP genotyping, QTL analysis, identifying genes orthologous to Arabidopsis ferrome, yeast complementation assay and genetic transformation to avoid the limitation from a single approach. We revealed several candidate genes potentially associated with potato plant Fe acquisition, PGSC0003DMG400024976 (metal transporter), PGSC0003DMG400013297 (oligopeptide transporter), PGSC0003DMG400021155 (IRT1) and IRTunannotated (an ortholog to the IRT gene that is not annotated in the potato genome). The microorganisms in the rhizosphere react intensely with the various metabolites released by plant roots in a variety of ways such as positive, negative, and neutral. These interactions can influence the uptake and transport of micronutrients in the plant roots. Therefore, the contribution of soil microorganisms in the rhizosphere to improve Fe supply of plants may play a key role in Fe biofortification, especially under real world field-based soil scenarios. We thus investigated rhizosphere microbial community diversity in Andean potato landraces to understand the role of plant-microbial interaction in potato Fe nutrient cycling. From the analysis of the high-throughput Illumina sequences of 16S and ITS region of ribosomal RNA gene, we found that both potato landraces with low and high Fe content in tubers and a landrace on which low or high Fe content fertilizer was applied to the leaf surface had large impacts on the rhizosphere fungal community composition. Indicator species analysis (ISA) indicated that Operational Taxonomic Units (OTUs) contributing most to these impacts were closely related to Eurotiomycetes and Leotiomycetes in the phylum Ascomycota, Glomeromycetes in the phylum Glomeromycota and Microbotryomycetes in the phylum Basidiomycota. Lots of species from these groups have been shown to regulate plant mineral nutrient cycling. Our research revealed potential candidate genes and fungal taxa involved in the potato plant Fe nutrient dynamics, which provides new insights into crop management and breeding strategies for sustainable Fe fortification in agricultural production. / Ph. D.