Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
Más filtros










Intervalo de año de publicación
1.
Food Nutr Bull ; 44(1_suppl): S14-S26, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-36016479

RESUMEN

This article presents the evolution of the biofortification program in Nigeria over the last decade and the role of interdisciplinary research in informing cost-effective, efficient, and inclusive development; implementation; and scaling of this program. Launched in 2011 to improve Nigeria's food systems to deliver accessible and affordable nutrients through commonly consumed staples, the Nigeria biofortification program was implemented through an effective partnership between the CGIAR and public, private, and civil society sectors at federal, state, and local levels. By the end of 2021, several biofortified varieties of Nigeria's 2 main staples, namely cassava and maize, were officially released for production by smallholders, with several biofortified varieties of other key staples (including pearl millet, rice, and sorghum) either under testing or in the release pipeline. In 2021, the program was estimated to benefit 13 million Nigerians consuming biofortified cassava and maize varieties. The evidence on the nutritional impact, consumer and farmer acceptance, and cost-effective scalability of biofortified crops documented by the program resulted in the integration of biofortified crops in several key national public policies and social protection programs; private seed and food company products/investments, as well as in humanitarian aid.


Asunto(s)
Biofortificación , Alimentos Fortificados , Humanos , Productos Agrícolas , Micronutrientes , Verduras
2.
Ann N Y Acad Sci ; 1517(1): 154-166, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36036193

RESUMEN

Nutrient enriched crops (NECs) were developed through biofortification as a tool to reach the world's most vulnerable. The delivery model developed by HarvestPlus for the scaling of NECs relies on commercial demand from food businesses and consumers, coupled with the ability to promote and market foods that comply with legislation. This review of standards, regulations, and laws across the value chain in 20 countries demonstrates that existing provisions for food labeling are sufficient to carry out sales and marketing of foods made from conventionally bred NECs. The term biofortification is not necessary to create demand and, potentially, is counterproductive. Promoting the natural source of vitamins and minerals and relevant nutrition claims is the most effective and simple way to signpost healthier products to consumers. Until 2021, it was not possible to distinguish NECs at the grain level from the market standard. The development of a globally relevant Publicly Available Specification allows traders to demand grains that offer a substantial increase in zinc, iron, or vitamin A. Addressing this gap at the grain level ensures that standards and regulations are available end-to-end in the food supply chain providing the enabling environment for the rapid scale of NECs.


Asunto(s)
Biofortificación , Alimentos Fortificados , Humanos , Productos Agrícolas , Nutrientes , Vitamina A
3.
Front Plant Sci ; 12: 703990, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34594348

RESUMEN

Biofortification breeding for three important micronutrients for human health, namely, iron (Fe), zinc (Zn), and provitamin A (PVA), has gained momentum in recent years. HarvestPlus, along with its global consortium partners, enhances Fe, Zn, and PVA in staple crops. The strategic and applied research by HarvestPlus is driven by product-based impact pathway that integrates crop breeding, nutrition research, impact assessment, advocacy, and communication to implement country-specific crop delivery plans. Targeted breeding has resulted in 393 biofortified crop varieties by the end of 2020, which have been released or are in testing in 63 countries, potentially benefitting more than 48 million people. Nevertheless, to reach more than a billion people by 2030, future breeding lines that are being distributed by Consultative Group on International Agricultural Research (CGIAR) centers and submitted by National Agricultural Research System (NARS) to varietal release committees should be biofortified. It is envisaged that the mainstreaming of biofortification traits will be driven by high-throughput micronutrient phenotyping, genomic selection coupled with speed breeding for accelerating genetic gains. It is noteworthy that targeted breeding gradually leads to mainstreaming, as the latter capitalizes on the progress made in the former. Efficacy studies have revealed the nutritional significance of Fe, Zn, and PVA biofortified varieties over non-biofortified ones. Mainstreaming will ensure the integration of biofortified traits into competitive varieties and hybrids developed by private and public sectors. The mainstreaming strategy has just been initiated in select CGIAR centers, namely, International Maize and Wheat Improvement Center (CIMMYT), International Rice Research Institute (IRRI), International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), International Institute of Tropical Agriculture (IITA), and International Center for Tropical Agriculture (CIAT). This review will present the key successes of targeted breeding and its relevance to the mainstreaming approaches to achieve scaling of biofortification to billions sustainably.

4.
Protoplasma ; 258(5): 1119-1131, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-33677735

RESUMEN

How to capture the rice varieties salt stress sensitivity? Here, we measure responses of root border cells (1 day, ± 60 mM NaCl) and apply multi-logistic quantification of growth variables (21 days, ± 60 mM NaCl) to two rice varieties, salt-sensitive IR29 and tolerant Pokkali. Thus, logistic models determine the maximum response velocities (Vmax) and times of half-maximum (T0) for root border cell (RBC) and growth parameters. Thereof, seven variables show logistic models (0.58 < R ≤ 1) and monotonous responses in both Pokkali and IR29: root to shoot ratio by water content, primary root length, shoot water, adventitious root number, shoot dry and fresh weight, and root dry weight. Moreover, the regression to lognormal distribution (R = 0.99) of these seven Vmax fractionated by T0 represents the rice variety's comprehensive response. Its quotient IR29/Pokkali is peaking at 98-fold higher velocity of IR29, thus capturing the variety's sensitivity. Consequently, our finding of 66-fold higher Vmax of primary root length response of IR29 indicates an essential salt sensor in the root, including RBC. Finally, the effects of salt stress on RBC confirm multi-logistic quantification, showing 36% decrease of RBC mucilage layer in IR29, without change in Pokkali. Inversely, RBC number of Pokkali increases 43% without change in IR29. Briefly, this suggests both RBC and multi-logistic quantification for the screening for salt tolerance in two thousand rice varieties.


Asunto(s)
Oryza , Tolerancia a la Sal
5.
Front Nutr ; 8: 746625, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35187017

RESUMEN

Micronutrient deficiency is most prevalent in developing regions of the world, including Africa and Southeast Asia where pearl millet (Pennisetum glaucum L.) is a major crop. Increasing essential minerals in pearl millet through biofortification could reduce malnutrition caused by deficiency. This study evaluated the extent of variability of micronutrients (Fe, Zn, Mn, and Na) and macronutrients (P, K, Ca, and Mg) and their relationship with Fe and Zn content in 14 trials involving pearl millet hybrids, inbreds, and germplasm. Significant genetic variability of macronutrients and micronutrients was found within and across the trials (Ca: 4.2-40.0 mg 100 g-1, Fe: 24-145 mg kg-1, Zn: 22-96 mg kg-1, and Na: 3.0-63 mg kg-1). Parental lines showed significantly larger variation for nutrients than hybrids, indicating their potential for use in hybrid parent improvement through recurrent selection. Fe and Zn contents were positively correlated and highly significant (r = 0.58-0.81; p < 0.01). Fe and Zn were positively and significantly correlated with Ca (r = 0.26-0.61; p < 0.05) and Mn (r = 0.24-0.50; p < 0.05). The findings indicate that joint selection for Fe, Zn, and Ca will be effective. Substantial genetic variation and high heritability (>0.60) for multiple grain minerals provide good selection accuracy prospects for genetic enhancement. A highly positive significant correlation between Fe and Zn and the nonsignificant correlation of grain macronutrients and micronutrients with Fe and Zn suggest that there is scope to achieve higher levels of Fe/Zn simultaneously in current pearl millet biofortification efforts without affecting other grain nutrients. Results suggest major prospects for improving multiple nutrients in pearl millet.

6.
Front Psychol ; 11: 561974, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33101133

RESUMEN

The Education and Learning Capital Approach (ELCA) has been widely used to investigate talent development. A research gap is the implicit consideration of the domain specificity of educational and learning capital. In an empirical study with 365 school students we investigated the domain specificity of the approach for the domains of school learning and learning to play a musical instrument. At the beginning of the school year, students filled out a version of the Questionnaire for Educational and Learning Capital (QELC) for both domains and also responded to other domain-related measures (self-efficacy, grades). Six weeks later, students filled out a learning diary for 1 week in which they reported their activities on an hourly basis and responded to questions concerning these activities. Based on the Sociotope Approach this procedure helped to identify times in which students actually practiced their musical instrument, times that students could potentially practice their musical instrument (objective action space), and times that students would be expected to practice their musical instrument (normative action space). Three hypotheses were tested and could be supported. First, the availability of educational and learning capital for school learning and learning an instrument differed. Second, a confirmatory factor analysis supported the factorial validity of the domain-specific capital measurements. Third, domain-congruent correlations were mostly higher than domain-incongruent correlations, i.e., the availability of educational and learning capital for school learning correlated more closely with variables related to school learning than with variables related to learning a musical instrument. Similarly, the availability of the capitals for learning a musical instrument correlated more closely with variables related to learning a musical instrument.

7.
Nat Commun ; 11(1): 5203, 2020 10 15.
Artículo en Inglés | MEDLINE | ID: mdl-33060603

RESUMEN

Ending all forms of hunger by 2030, as set forward in the UN-Sustainable Development Goal 2 (UN-SDG2), is a daunting but essential task, given the limited timeline ahead and the negative global health and socio-economic impact of hunger. Malnutrition or hidden hunger due to micronutrient deficiencies affects about one third of the world population and severely jeopardizes economic development. Staple crop biofortification through gene stacking, using a rational combination of conventional breeding and metabolic engineering strategies, should enable a leap forward within the coming decade. A number of specific actions and policy interventions are proposed to reach this goal.


Asunto(s)
Biofortificación/métodos , Ingeniería Metabólica/métodos , Cruzamiento , Productos Agrícolas/genética , Países en Desarrollo , Abastecimiento de Alimentos , Alimentos Fortificados , Salud Global , Humanos , Desnutrición/prevención & control , Micronutrientes , Minerales , Oryza , Plantas/genética , Plantas Modificadas Genéticamente , Formulación de Políticas , Provitaminas , Desarrollo Sostenible/economía , Desarrollo Sostenible/tendencias , Naciones Unidas , Vitaminas
8.
Clin Neuropsychol ; 34(5): 1004-1024, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-31775575

RESUMEN

Objective: Noncredible symptom claims, regularly expected in forensic contexts, may also occur in clinical and rehabilitation referral contexts. Hidden motives and secondary gain expectations may play a significant role in clinical patients. We studied the prevalence of noncredible symptom report in patients treated for minor mental disorders in an inpatient setting.Method: Five hundred and thirty seven clinical inpatients of a psychosomatic rehabilitation center were studied (mean age: 50.2 years; native speakers of German). They were referred for treatment of depression, anxiety, somatoform disorder, adjustment disorder, and neurasthenia. Results of two symptom validity tests (Structured Inventory of Malingered Symptomatology, SIMS; Self-Report Symptom Inventory, SRSI) and the Beck Depression Inventory-II (BDI-II) were analyzed.Results: At screening level, 34.5% and 29.8% of the patients were found to presumably overreport symptoms on the SIMS and SRSI, respectively. At the standard cut score of the SRSI (maximum false positive rate: 5%), the proportion of diagnosed overreporting was 18.8%. SIMS and SRSI pseudosymptom endorsement correlated at .73. Highly elevated depressive symptom claims with BDI-II scores above 40, found in 9.3% of the patients, were associated with elevated pseudosymptom endorsement. Moreover, extended times of sick leave and higher expectations of disability pension were associated with elevated pseudosymptom endorsement.Conclusions: The prevalence of symptom overreporting in some clinical patient groups is a serious, yet underinvestigated problem. The current estimates yielded a high prevalence of distorted, noncredible symptom claims in psychosomatic rehabilitation patients. The challenges arising to health professionals working in such settings are immense and need more consideration.


Asunto(s)
Simulación de Enfermedad/diagnóstico , Pruebas Neuropsicológicas/normas , Femenino , Humanos , Pacientes Internos , Masculino , Simulación de Enfermedad/psicología , Uso Excesivo de los Servicios de Salud , Persona de Mediana Edad , Prevalencia , Reproducibilidad de los Resultados
9.
Protoplasma ; 256(2): 331-347, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30097762

RESUMEN

How many subcellular targets of the beneficial silicon effect do exist in salt-stressed rice? Here, we investigate the effects of silicon on the different components of salt stress, i.e., osmotic stress, sodium, and chloride toxicity. These components are separated by multivariate analysis of 18 variables measured in rice seedlings (Oryza sativa L.). Multivariate analysis can dissect vectors and extract targets as principal components, given the regressions between all variables are known. Consequently, the exploration of 153 correlations and 306 regression models between all variables is essential, and regression parameters for variables of shoot (silicon, sodium, chloride, carotenoids, chlorophylls a and b, and relative growth rate) and variables of shoot and root (hydrogen peroxide, ascorbate peroxidase (APX), catalase (CAT), fresh weight, dry weight, root-to-shoot ratio) are determined. The regression models [log (y) = y0 + a × log (x)] are confirmed by variance analysis of global goodness of fits (p < 0.0001). Thereby, logarithmic transformation yields linearization for multivariate analysis by Pearson's correlation. Four principal components are extracted: two targets of osmotic stress, one target of sodium toxicity, and one target of chloride toxicity. Thereby, silicon improves salt tolerance by increasing APX and CAT activities and decreasing hydrogen peroxide, salt ion accumulation, photosynthetic pigment losses, and growth inhibition. Salt stress increases silicon uptake pointing to a physiological regulation of plant salt stress in the presence of silicon. This mechanism and its four components are promising targets for further agricultural application.


Asunto(s)
Oryza/química , Silicio/química , Cloruro de Sodio/química , Análisis Multivariante , Estrés Salino
10.
Environ Sci Pollut Res Int ; 26(32): 32698-32707, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30547341

RESUMEN

The anaerobic digestion of wastewater from the cleaning of tank cars transporting food and fodder was investigated in both bench and pilot scales with a single-stage, mesophilic (39 °C), completely mixed process. The promising results lead to the planning and building of a 1200-m3 full-scale biogas plant at TS-Clean cleaning station in Fahrbinde, Germany. Due to softened water used in the cleaning of the car tanks, the alkalinity in the digester decreased as predicted by the physicochemical model developed for this treatment process. The model showed that 2.4 kg NaHCO3/m3 of wastewater has to be added in order to control digester pH at 7.2 and to maintain the digester alkalinity at 3.1 g CaCO3/L. In a laboratory study, the decrease of alkalinity caused a volatile organic acids accumulation and pH drop below the optimal range. In this case, if chemical buffering was not added into the digester, the digester deteriorated. In a 3-year investigation, we confirmed that the strongly polluted WW from the cleaning of tank cars transporting food and fodder is suitable for an anaerobic treatment if the organic loading rate is controlled below 4 kg COD/m3/day, digester alkalinity is adjusted by NaHCO3, and micronutrients are added despite constant considerable variations in strength and composition of the wastewater. A biogas yield of 35-45 m3 CH4/m3 of wastewater and a COD elimination of 80-90% were achieved in bench- and pilot-scale experiments and are achieved in the full-scale biogas plant. The full-scale biogas plant is working stable with a biogas yield of 68 m3 biogas/m3 of wastewater.


Asunto(s)
Alimentación Animal , Biocombustibles , Eliminación de Residuos Líquidos/métodos , Anaerobiosis , Reactores Biológicos , Alemania , Metano/análisis , Aguas Residuales
11.
Rehabilitation (Stuttg) ; 57(4): 256-264, 2018 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-29183101

RESUMEN

AIM OF THIS STUDY: Apart from the reduction of symptoms and the restoration of working ability, return to work is a long-term goal of medical rehabilitation. The aim of this study is to analyze the influence of work motivation on the outcome of rehabilitation. METHODS: The data basis consists of N=998 patients at the psychosomatic department of the Oberharz Rehabilitation Center as well as data from insurance accounts. Using multiple linear regression analysis the predictive power of work motivation on rehabilitation outcome as well as different facets of work motivation in their function as predictors are analyzed. RESULTS: Only minor statistical relations could be found between work motivation and rehabilitation success when also taking employment status of the previous year and subjective vocational disability into account. A small predictive power can be attributed to work motivation as a factor in rehabilitation success in the sense of a reduction of symptoms. Particular facets of work motivation are suitable to predict rehabilitation success. Patients with a work motivation risk profile differ from patients with a normal work motivation profile as regards their capacity to work in the year following rehabilitation treatment. CONCLUSION: Work motivation represents a relevant construct in rehabilitation success but is strongly influenced by individual factors. During rehabilitation, individual problems which influence work motivation should be taken into account more strongly.


Asunto(s)
Empleo/estadística & datos numéricos , Motivación , Trastornos Psicofisiológicos/rehabilitación , Rehabilitación/psicología , Reinserción al Trabajo/psicología , Evaluación de la Discapacidad , Alemania , Humanos , Trastornos Psicofisiológicos/psicología , Calidad de Vida , Resultado del Tratamiento
12.
Parasitol Res ; 115(1): 225-39, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26412058

RESUMEN

Plant essential oils have been suggested as a promising alternative to the established mosquito repellent DEET (N,N-diethyl-meta-toluamide). Searching for an assay with generally available equipment, we designed a new audiovisual assay of repellent activity against mosquitoes "Singing in the Tube," testing single mosquitoes in Drosophila cultivation tubes. Statistics with regression analysis should compensate for limitations of simple hardware. The assay was established with female Culex pipiens mosquitoes in 60 experiments, 120-h audio recording, and 2580 estimations of the distance between mosquito sitting position and the chemical. Correlations between parameters of sitting position, flight activity pattern, and flight tone spectrum were analyzed. Regression analysis of psycho-acoustic data of audio files (dB[A]) used a squared and modified sinus function determining wing beat frequency WBF ± SD (357 ± 47 Hz). Application of logistic regression defined the repelling velocity constant. The repelling velocity constant showed a decreasing order of efficiency of plant essential oils: rosemary (Rosmarinus officinalis), eucalyptus (Eucalyptus globulus), lavender (Lavandula angustifolia), citronella (Cymbopogon nardus), tea tree (Melaleuca alternifolia), clove (Syzygium aromaticum), lemon (Citrus limon), patchouli (Pogostemon cablin), DEET, cedar wood (Cedrus atlantica). In conclusion, we suggest (1) disease vector control (e.g., impregnation of bed nets) by eight plant essential oils with repelling velocity superior to DEET, (2) simple mosquito repellency testing in Drosophila cultivation tubes, (3) automated approaches and room surveillance by generally available audio equipment (dB[A]: ISO standard 226), and (4) quantification of repellent activity by parameters of the audiovisual assay defined by correlation and regression analyses.


Asunto(s)
Culex/fisiología , Vuelo Animal/efectos de los fármacos , Repelentes de Insectos/farmacología , Aceites de Plantas/farmacología , Vocalización Animal/efectos de los fármacos , Animales , Recursos Audiovisuales , Aceite de Clavo/farmacología , Culex/efectos de los fármacos , DEET/efectos adversos , DEET/farmacología , Eucalyptus , Aceite de Eucalipto , Femenino , Lavandula , Monoterpenos/farmacología , Aceites Volátiles/farmacología , Análisis de Regresión , Aceite de Árbol de Té/farmacología
13.
Theor Appl Genet ; 125(2): 235-46, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22450859

RESUMEN

Biofortification for pro-vitamin A content (pVAC) of modern maize inbreds and hybrids is a feasible way to deal with vitamin A deficiency in rural areas in developing countries. The objective of this study was to evaluate the probability of success of breeding strategies when transferring the high pVAC present in donors to elite modern-adapted lines. For this purpose, a genetic model was built based on previous genetic studies, and different selection schemes including phenotypic selection (PS) and marker-assisted selection (MAS) were simulated and compared. MAS for simultaneously selecting all pVAC genes and a combined scheme for selecting two major pVAC genes by MAS followed by ultra performance liquid chromatography screening for the remaining genetic variation on pVAC were identified as being most effective and cost-efficient. The two schemes have 83.7 and 84.8% probabilities of achieving a predefined breeding target on pVAC and adaptation in one breeding cycle under the current breeding scale. When the breeding scale is increased by making 50% more crosses, the probability values could reach 94.8 and 95.1% for the two schemes. Under fixed resources, larger early generation populations with fewer crosses had similar breeding efficiency to smaller early generation populations with more crosses. Breeding on a larger scale was more efficient both genetically and economically. The approach presented in this study could be used as a general way in quantifying probability of success and comparing different breeding schemes in other breeding programs.


Asunto(s)
Cruzamiento/métodos , Vitamina A/metabolismo , Zea mays/genética , Zea mays/metabolismo , Adaptación Biológica/genética , Cruzamiento/economía , Simulación por Computador , Análisis Costo-Beneficio , Cruzamientos Genéticos , Genes de Plantas/genética , Genética de Población , Genotipo , Modelos Genéticos , Fenotipo , Selección Genética , Zea mays/economía
14.
Food Nutr Bull ; 32(1 Suppl): S31-40, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21717916

RESUMEN

BACKGROUND: The density of minerals and vitamins in food staples eaten widely by the poor may be increased either through conventional plant breeding or through the use of transgenic techniques, a process known as biofortification. OBJECTIVE: HarvestPlus seeks to develop and distribute varieties of food staples (rice, wheat, maize, cassava, pearl millet, beans, and sweet potato) that are high in iron, zinc, and provitamin A through an interdisciplinary, global alliance of scientific institutions and implementing agencies in developing and developed countries. METHODS: In broad terms, three things must happen for biofortification to be successful. First, the breeding must be successful--high nutrient density must be combined with high yields and high profitability. Second, efficacy must be demonstrated--the micronutrient status of human subjects must be shown to improve when they are consuming the biofortified varieties as normally eaten. Thus, sufficient nutrients must be retained in processing and cooking and these nutrients must be sufficiently bioavailable. Third, the biofortified crops must be adopted by farmers and consumed by those suffering from micronutrient malnutrition in significant numbers. RESULTS: Biofortified crops offer a rural-based intervention that, by design, initially reaches these more remote populations, which comprise a majority of the undernourished in many countries, and then penetrates to urban populations as production surpluses are marketed. In this way, biofortification complements fortification and supplementation programs, which work best in centralized urban areas and then reach into rural areas with good infrastructure. CONCLUSIONS: Initial investments in agricultural research at a central location can generate high recurrent benefits at low cost as adapted, biofortified varieties become available in country after country across time at low recurrent costs.


Asunto(s)
Productos Agrícolas/química , Alimentos Fortificados/economía , Micronutrientes/deficiencia , Semillas/química , Deficiencia de Vitamina A/epidemiología , Disponibilidad Biológica , Cruzamiento , Análisis Costo-Beneficio , Productos Agrícolas/economía , Productos Agrícolas/genética , Países en Desarrollo , Variación Genética , Humanos , Hierro/farmacocinética , Deficiencias de Hierro , Micronutrientes/administración & dosificación , Plantas Modificadas Genéticamente , Prevalencia , Población Rural , Semillas/genética , Zinc/deficiencia , Zinc/farmacocinética
15.
J Nutr ; 139(10): 1920-5, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19710154

RESUMEN

Biofortification of crops that provide major food staples to large, poor rural populations offers an appealing strategy for diminishing public health problems attributable to micronutrient deficiencies. The objective of this first-stage human study was to determine the increase in quantity of zinc (Zn) absorbed achieved by biofortifying wheat with Zn. Secondary objectives included evaluating the magnitude of the measured increases in Zn absorption as a function of dietary Zn and phytate. The biofortified and control wheats were extracted at high (95%) and moderate (80%) levels and Zn and phytate concentrations measured. Adult women with habitual diets high in phytate consumed 300 g of 95 or 80% extracted wheat as tortillas for 2 consecutive days using either biofortified (41 mg Zn/g) or control (24 mg Zn/g) wheat. All meals for the 2-d experiment were extrinsically labeled with Zn stable isotopes and fractional absorption of Zn determined by a dual isotope tracer ratio technique. Zn intake from the biofortified wheat diet was 5.7 mg/d (72%) higher at 95% extraction (P < 0.001) and 2.7 mg/d (68%) higher at 80% extraction compared with the corresponding control wheat (P = 0.007). Zn absorption from biofortified wheat meals was (mean +/- SD) 2.1 +/- 0.7 and 2.0 +/- 0.4 mg/d for 95 and 80% extraction, respectively, both of which were 0.5 mg/d higher than for the corresponding control wheat (P < 0.05). Results were consistent with those predicted by a trivariate model of Zn absorption as a function of dietary Zn and phytate. Potentially valuable increases in Zn absorption can be achieved from biofortification of wheat with Zn.


Asunto(s)
Harina/análisis , Alimentos Fortificados/análisis , Triticum/química , Zinc/química , Zinc/metabolismo , Adolescente , Adulto , Estudios Transversales , Suplementos Dietéticos , Femenino , Humanos , México , Adulto Joven , Zinc/orina , Isótopos de Zinc
16.
Theor Appl Genet ; 118(4): 683-94, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19034410

RESUMEN

A strategy combining single backcrossing with selected bulk breeding has been successfully used in wheat improvement at CIMMYT to introgress rust resistant genes from donor parents to elite adapted cultivars. In this research, the efficiency of this breeding strategy was compared to other crossing and selection strategies through computer simulation. Results indicated this breeding strategy has advantages in retaining or improving the adaptation of the recurrent parents, and at the same time transferring most of the desired donor genes in a wide range of scenarios. Two rounds of backcrossing have advantages when the adaptation of donor parents is much poorer than that of the adapted parents, but the advantage of three rounds of backcrossing over two rounds is minimal. We recommend using the single backcrossing breeding strategy (SBBS) when three conditions are met: (1) multiple genes govern the phenotypic traits to be transferred from donor parents to adapted parents, (2) the donor parents have some favorable genes that may contribute to the improvement of adaptation in the recipient parents, and (3) conventional phenotypic selection is being applied, or individual genotypes cannot be precisely identified. We envisage that all three conditions commonly exist in modern breeding programs, and therefore believe that SBBS could be applied widely. However, we do not exclude the use of repeated backcrossing if the transferred genes can be precisely identified by closely linked molecular markers, and the donor parents have extremely poor adaptation.


Asunto(s)
Adaptación Biológica/genética , Cruzamiento/métodos , Inmunidad Innata/genética , Triticum/genética , Simulación por Computador , Cruzamientos Genéticos
17.
Protoplasma ; 234(1-4): 33-50, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18807117

RESUMEN

A comparison of the responses of extracellular pH, buffering capacity and actin cytoskeleton in autotroph and heterotroph Chenopodium rubrum cells to heat shock revealed cell-specific reactions: alkalinization caused by the heat shock at 25-35 degrees C was higher in heterotroph cells and characterized by heat shock-induced changes in the actin cytoskeleton and ring formation at 35-37 degrees C. Rings (diameter up to 3 mum) disappeared and extracellular pH recovered after the heat-shocked cells were transferred into control medium. At 41 degrees C, no rings but a network of coarse actin filaments were induced; at higher temperatures, fragmentation of the actin cytoskeleton and release of buffering compounds occurred, indicating sudden membrane leakage at 45-47 degrees C. The calcium chelator EGTA [ethylene-glycol-bis(beta-aminoethyl-ether)-N,N,N',N'-tetraacetic-acid] increased the frequency of heat shock-induced rings. Ionophore (10 microM nigericin) and the sodium/proton antiport blocker [100 microM 5-(N-ethyl-N-isopropyl)-amiloride] mimicked the effect of the 37 degrees C heat shock. The cytoskeleton inhibitors latrunculin B, cytochalasin D and 2,3-butanedione monoxime inhibited ring formation but not alkalinization. In autotroph cells, the treatment with nigericin (10 microM) produced rings, although the actin cytoskeleton was not affected by temperatures up to 45 degrees C. We conclude that Chenopodium cells express a specific temperature sensor that has ascendancy over the organization of the actin cytoskeleton; this is probably a temperature- and potential-sensitive proton-transporting mechanism that is dependent on the culture conditions of the heterotroph cells.


Asunto(s)
Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Chenopodium/fisiología , Respuesta al Choque Térmico , Citoesqueleto de Actina/ultraestructura , Actinas/ultraestructura , Procesos Autotróficos/efectos de los fármacos , Procesos Autotróficos/fisiología , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Quelantes/farmacología , Chenopodium/metabolismo , Chenopodium/ultraestructura , Citocalasina D/farmacología , Citoesqueleto/metabolismo , Citoesqueleto/ultraestructura , Diacetil/análogos & derivados , Diacetil/farmacología , Ácido Egtácico/farmacología , Inhibidores Enzimáticos/farmacología , Respuesta al Choque Térmico/efectos de los fármacos , Respuesta al Choque Térmico/fisiología , Procesos Heterotróficos/efectos de los fármacos , Procesos Heterotróficos/fisiología , Ionóforos/farmacología , Microscopía Confocal , Nigericina/farmacología , Inhibidores de la Síntesis del Ácido Nucleico/farmacología , Protones , Tiazolidinas/farmacología
18.
J Plant Physiol ; 165(16): 1655-66, 2008 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-18433930

RESUMEN

We investigated the response of extracellular phosphatase to heat shock in heterotrophic Chenopodium rubrum L. cell cultures. Surprisingly, in contrast to the generally used acid phosphatase, an extracellular alkaline phosphatase showed the most sensitive response. This phosphatase was characterized as a marker for cellular stimulation by its high correlations with induced changes of extracellular pH: 10microM nigericin (correlation coefficient r=0.91), 100microM salicylic acid (r=0.84), heat shock 5min 37 degrees C (r=0.79), and heat shock after pre-treatment with 5microM fusicoccin (r=0.92) or 0.5% ethanol (r=0.90). Cellular stimulation was estimated with concentrations of acids and bases, yielding similar levels of pH change (0.5 pH) in cell-free supernatant: salicylic acid (200microM), benzoic acid (600microM), HCl (140microM), NaOH (100microM), and KOH (100microM). The Golgi apparatus inhibitor Brefeldin A (200microM) reduced the heat-shock-induced phosphatase (-33%). The pH optimum of heat-shock-induced phosphatase was 3; however, there the proportion of constitutive phosphatase was higher than at pH 8-9.5, indicating different pH dependence of constitutive and induced activity. Thus, heat-shock-induced phosphatase was characterized by alkaline activity with inhibitors (10microM molybdate: -52%, 2.5mM phosphate: -64%, 10microM ZnCl(2): -82%), substrates (2.5mM, tyrosine phosphate: 255pkat g(-1), p-nitrophenyl phosphate: 92pkat g(-1), serine phosphate: 0, threonine phosphate: 0), Hill coefficient (nH=1.4) indicating two binding sites, and the extent of heat-shock stimulation (p-nitrophenyl phosphate: +190%, tyrosine phosphate: +180%). SDS-PAGE showed a correlation of alkaline phosphatase with the heat-shock-induced release of highly N-glycosylated 53kDa protein, detected by peroxidase-labeled concanavalin A affinoblotting after endoglycosidase H treatment. The 53kDa protein showed no in-gel phosphatase activity after SDS-PAGE and regeneration treatment, in contrast to a putative dimer (105kDa).


Asunto(s)
Fosfatasa Alcalina/metabolismo , Chenopodium/enzimología , Exocitosis , Respuesta al Choque Térmico , Proteínas de Plantas/metabolismo , Biomarcadores/metabolismo , Brefeldino A/farmacología , Células Cultivadas , Chenopodium/citología , Chenopodium/efectos de los fármacos , Electroforesis en Gel de Poliacrilamida , Respuesta al Choque Térmico/efectos de los fármacos , Calor , Concentración de Iones de Hidrógeno , Cinética , Nigericina/farmacología , Ácido Salicílico/farmacología
19.
Curr Opin Plant Biol ; 11(2): 166-70, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18314378

RESUMEN

Micronutrient malnutrition affects more than half of the world population, particularly in developing countries. Concerted international and national fortification and supplementation efforts to curb the scourge of micronutrient malnutrition are showing a positive impact, alas without reaching the goals set by international organizations. Biofortification, the delivery of micronutrients via micronutrient-dense crops, offers a cost-effective and sustainable approach, complementing these efforts by reaching rural populations. Bioavailable micronutrients in the edible parts of staple crops at concentrations high enough to impact on human health can be obtained through breeding, provided that sufficient genetic variation for a given trait exists, or through transgenic approaches. Research and breeding programs are underway to enrich the major food staples in developing countries with the most important micronutrients: iron, provitamin A, zinc and folate.


Asunto(s)
Productos Agrícolas/metabolismo , Alimentos Fortificados , Desnutrición/prevención & control , Micronutrientes/deficiencia , Cruzamiento , Humanos , Plantas Modificadas Genéticamente
20.
Theor Appl Genet ; 115(6): 819-35, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17768603

RESUMEN

The International Adaptation Trial (IAT) is a special purpose nursery designed to investigate the genotype-by-environment interactions and worldwide adaptation for grain yield of Australian and CIMMYT spring bread wheat (Triticum aestivum L.) and durum wheat (T. turgidum L. var. durum). The IAT contains lines representing Australian and CIMMYT wheat breeding programs and was distributed to 91 countries between 2000 and 2004. Yield data of 41 reference lines from 106 trials were analysed. A multiplicative mixed model accounted for trial variance heterogeneity and inter-trial correlations characteristic of multi-environment trials. A factor analytic model explained 48% of the genetic variance for the reference lines. Pedigree information was then incorporated to partition the genetic line effects into additive and non-additive components. This model explained 67 and 56% of the additive by environment and non-additive by environment genetic variances, respectively. Australian and CIMMYT germplasm showed good adaptation to their respective target production environments. In general, Australian lines performed well in south and west Australia, South America, southern Africa, Iran and high latitude European and Canadian locations. CIMMYT lines performed well at CIMMYT's key yield testing location in Mexico (CIANO), north-eastern Australia, the Indo-Gangetic plains, West Asia North Africa and locations in Europe and Canada. Maturity explained some of the global adaptation patterns. In general, southern Australian germplasm were later maturing than CIMMYT material. While CIANO continues to provide adapted lines to northern Australia, selecting for yield among later maturing CIMMYT material in CIANO may identify lines adapted to southern and western Australian environments.


Asunto(s)
Adaptación Biológica/genética , Triticum/genética , Australia , Cruzamiento , Modelos Genéticos , Linaje , Triticum/crecimiento & desarrollo , Triticum/fisiología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...