Zn In Grain Research Articles

IMPROVEMENT OF CALCAREOUS SOIL CHEMICAL PROPERTIES AND ITS PRODUCTIVITY AS AFFECTED BY FARMING METHODS AND ORGANIC MANURES APPLICATIONS

Organic manures are traditionally used for supplying plant nutrients. Their volume and other operational problems forced the farmers to use inorganic fertilizers. The recycling of organic waste is considered one of the major solutions to get rid of huge piles of wastes. The management of soil organic matter is critical to maintain a sustainable productive organic farming system. They possess many desirable soil properties and exert beneficial effect on the soil characteristics. In this regard, a field experiment was carried out on a calcareous sandy loam soil cultivated with bean (Nubaria 1) at El-Nubaria Agricultural Research Station, El- Behera Governorate during two successive winter seasons of 2012/2013 and 2013 / 2014 to investigate the effect of organic manures (rice straw compost and chicken manure) as organic amendments under farming methods (row and strew) on calcareous soilchemical properties and its productivity. Data indicated that, EC values (dSm-1) and pH values of the studied soil were decreased as a result of using rice straw compost and chicken manure under different cultivation methods. The OM content and cation exchange capacity of the soil after bean harvest were increased by the studied treatments. The high increase was attained by using rice straw compost with row farming method. Also, results showed that, the treatment with rice straw compost and row farming method resulted increase in the soil content of available N, P, K and Fe, Mn and Zn after harvest of bean. Also, there was a significant increase in N, P and K contents of bean grains with rice straw compost or chicken manure treatments compared with control. The same treatments caused an increase in the concentrations of Fe, Mn and Zn in grains. The bean plant grown under all the studied treatments gave higher yield than the control under calcareous soil conditions and the highest values of straw and grain yields were recorded by using rice straw compost with row cultivation method. As a general, it is concluded that the row cultivation method and the rice straw compost addition had beneficial effect at the different soil properties and crop yield of broad bean plants grown on calcareous soil compared with other treatments under study.

Zn Diffusion and α-Fe(Zn) Layer Growth During Annealing of Zn-Coated B Steel

Direct hot press forming of Zn-coated 22MnB5 steels is impeded by micro-cracks that occur in the substrate due to the presence of Zn during the forming process. A study was therefore undertaken to quantify concentration of Zn across the α-Fe(Zn) coating and on grain boundaries in the α-Fe(Zn) layer and the underlying γ-Fe(Zn) substrate after isothermal annealing of Zn-coated 22MnB5 at 1173 K (900 °C) and to link the Zn distribution to the amount and type of micro-cracks observed in deformed samples. Finite difference model was developed to describe Zn diffusion and the growth of the α-Fe(Zn) layer. The penetration of Zn into the γ-Fe(Zn) substrate after 600 seconds annealing at 1173 K (900 °C) through bulk diffusion is estimated to be 3 μm, and the diffusion depth of Zn on the γ-Fe(Zn) grain boundaries is estimated to be 6 μm, which is significantly shorter than the maximum length (15 to 50 μm) of the micro-cracks formed in the severely stressed conditions, indicating that the Zn diffusion into the γ-Fe(Zn) from the α-Fe(Zn) during annealing is not correlated to the depth of micro-cracks. On the other hand, the maximum amount of Zn present in α-Fe(Zn) layer decreases with annealing time as the layer grows and Zn oxidizes, and the amount of Zn-enriched areas inside the α-Fe(Zn) layer is reduced leading to reduced length of cracking. Solid-Metal-Induced Embrittlement mechanism is proposed to explain the benefit of extended annealing on reduced depth of micro-crack penetration into the γ-Fe(Zn) substrate.

Zinc accumulation and remobilization in winter wheat as affected by phosphorus application

Although the interaction between phosphorus (P) and zinc (Zn) in crop production has long been a focus of plant nutrition research, the effects of P on the Zn content of cereal crops remains unclear, especially in intensive agricultural systems with high rates of P application and low levels of available Zn. The current study of a high-yielding winter wheat system on the North China Plain compared the effects of P application (0, 25, 50, 100, 200, and 400kgha−1) on yield, biomass accumulation, Zn accumulation, Zn uptake during all crop stages, and Zn remobilization. In two growing seasons (2011–2012 and 2012–2013), the results indicated that P application significantly increased wheat grain yield and shoot biomass. Phosphorus application also significantly increased the P concentration and decreased the Zn concentration in shoots. Phosphorus application increased P accumulation (kg ha−1) throughout the growing season but the effect of P application on Zn accumulation (g ha−1) depended on crop stage. Zn accumulation increased with increasing P application rates at the jointing stage. Zn accumulation at the flowering and maturity stage increased with application of 25 and 50kgPha−1 but decreased with application of 100–400kgPha−1 in both cropping seasons. The Zn harvest index and the ratio of pre-anthesis to post-anthesis Zn accumulation were not greatly affected by P application rate. Zn remobilization into grain increased with application of 0–50kgPha−1 but then decreased with the further application of 50–400kgPha−1 in both cropping seasons. Overall, the effects of P application on Zn nutrition depended on P rate and crop stage. Lower P application rates (<50kgha−1) increased Zn accumulation especially after the flowering stage and increased Zn remobilization to grain. High rates of P (>50kgha−1), in contrast, significantly decreased Zn accumulation and remobilization in this high-yielding winter wheat system. The results indicate that optimal P management in intensive agricultural systems is needed to ensure both high wheat yields and high levels of Zn in grain required for human nutrition.

Application of ZnSO4 or Zn-EDTA fertilizer to a calcareous soil: Zn diffusion in soil and its uptake by wheat plants.

The objective of this study was to compare the efficiency of two Zn sources and two application methods on (i) Zn diffusion from fertilized soil to unfertilized soil, (ii) grain Zn concentration and (iii) grain Zn bio-accessibility to humans. In the laboratory experiment, 20 mg ZnSO4 or 4 mg Zn-EDTA were applied to a 5 mm and 1 mm-wide space in the soil in the half-cell technique. In the greenhouse experiment, Zn-ZnSO4 or Zn-ethylenediaminetetraacetic acid (Zn-EDTA) was mixed or banded with the soil at a rate of 20 or 4 mg Zn kg(-1) , respectively. The results from the diffusion experiment showed that both the extractability and the diffusion coefficient of Zn were higher when Zn fertilizer was applied to a 1 mm-wide space than when it was applied to a 5 mm-wide space. Zn-EDTA had a greater diffusion distance than ZnSO4 . The greenhouse experiment showed that the mixed ZnSO4 application and the Zn-EDTA application (both mixed and banded) treatments significantly increased grain Zn concentration and bio-accessibility. The positive effect of Zn-EDTA on grain Zn concentrations and bio-accessibility was greater than that of ZnSO4 . The banded application reduced the effectiveness of ZnSO4 but not of Zn-EDTA. It was concluded that Zn-EDTA was a better Zn source than ZnSO4 for increasing grain Zn content in a potentially Zn-deficient calcareous soil.

Effect of Co-planted Purslane (Portulaca Oleracea L.) on Cd Accumulation by Sunflower in Different Levels of Cd Contamination and Salinity: A Pot Study

Heavy metal bioaccumulation can be affected by various crop-weed interactions that potentially exist in agroecosystems. A pot experiment was conducted to evaluate the role of rhizosphere interaction of sunflower and purslane (Portulaca oleracea L.) weed on cadmium (Cd) uptake and its allocation to sunflower grains. The experimental treatments consisted of two cropping systems (mono and mixed culture), two adjusted salinity levels (0 and 0.5% NaCl) and three artificial levels of Cd in soil (Control, 3 and 6 mg kg−1). The results showed that the growth of sunflower in the presence of purslane in comparison to mono culture of sunflower led to change of total Cd content and Cd allocated to grains only in saline conditions. Promoting effects of salinity on Cd concentration of grain were alleviated where sunflower was co-planted with purslane. Besides, supply of Zn in grains of co-planted sunflower was strongly affected by salinity. Results of this study revealed that although co-planted purslane could alter conditions in the shared rhizosphere, it had no effect on enhancing Cd uptake by neighboring sunflower directly.

Crystallography of grain refinement in cast zinc–copper alloys

Adding the peritectic forming element Cu effectively reduced the average grain size of cast Zn by over 85%. At a specified cast condition, the smallest grain size was obtained at 2 wt% Cu addition. A further increase in Cu content led to grain coarsening in the cast Zn–Cu alloys. Although the solute effect of Cu was predominately responsible for the grain refinement through restriction of the grain growth, it was found that the variation of grain size is also closely related to the formation of the pro-peritectic phase, ɛ-CuZn4. Crystallographic calculations using the edge-to-edge matching model showed low interatomic misfit and interplanar mismatch between Zn and the ɛ-CuZn4 phase. In addition, a reproducible h.c.p.–h.c.p. (h.c.p. denotes hexagonal close-packed) orientation relationship between Zn and the ɛ-CuZn4 particles (located within the Zn grain centres) was also experimentally determined using the electron backscattered diffraction method. This indicated the high potency of the pro-peritectic ɛ-CuZn4 particles as effective heterogeneous nucleation sites for η-Zn, which further refined the Zn grains. However, when the Cu content was over 2.0 wt%, formation of large ɛ-CuZn4 particles resulted in grain coarsening of the cast alloys.

Relative Efficiency of Zinc Sulphate and Chelated Zinc on Zinc Biofortification of Rice Grains and Zinc Use-Efficiency in Basmati Rice

Zinc deficiency in human nutrition is widespread in developing Asian and African countries where cereal grains are the staple food. Agronomic biofortification of Zn is a new innovative approach to get rid of Zn malnutrition from the poorest of the poor rural masses, who will never have money to buy mineral supplements nor can afford to improve the components of their diet by incorporating animal products. Hence, a field experiment was conducted during 2010 and 2011 on a sandy clay-loam soil (typic Ustochrept) at New Delhi, India to study the effect of NPK fertilization and to compare zinc sulphate heptahydrate (ZnSHH) and Zn–EDTA for growth, yield attributes, grain and straw yield, Zn concentration and uptake and Zn use efficiency in Basmati rice cultivar ‘Pusa Sugandh 5’ when applied to soil ZnSHH and Zn–EDTA were equally effective. Three foliar applications of ZnSHH increased Zn concentration and uptake by rice as compared to its soil application. Three foliar applications of Zn–EDTA (at tillering, booting and grain filling stages) was the best treatment and recorded significantly better growth, higher values for yield attributes, higher grain and straw yield and higher concentration and uptake of Zn in grain and straw of Basmati rice than soil application of ZnSHH or Zn–EDTA and two or a single foliar application of ZnSHH or Zn–EDTA. Three foliar applications of 0.5 % solution of Zn–EDTA recorded significantly higher head rice recovery than soil application. The highest KLBC, KLAC and KLER were obtained with three foliar applications of 0.5 % solution of Zn–EDTA.

Exploring the Role of Zinc in Maize (Zea Mays L.) through Soil and Foliar Application

Maize (Zea mays L.) is considered as high nutrient demanding crop and needs balanced nutrition. It is also regarded sensitive to zinc deficiency. Zinc is mostly deficient in soils and application of zinc fertilizer is required to explore its full potential. Crop species and even cultivars within species vary in their Zn requirement. A field experiment was conducted during spring 2011 at Agronomic Research Area, University of Agriculture, Faisalabad, Pakistan to evaluate the comparative efficacy of Zn uptake and grain yield in three maize hybrids (Pioneer-32 F 10, Monsanto-6525 and Hycorn-8288) through the application of Zn in the form of ZnSO4. The ZnSO4 treatments comprised; soil application at the time of sowing @ 12 kg ha-1, foliar application at vegetative stage (9 leaf stage) @ 1% ZnSO4 solution and foliar application at reproductive stage (anthesis) @ 1% ZnSO4 solution and one treatment was kept as a control. The experimental results showed substantial difference in yield and yield contributing parameters such as plant population at harvest, number of grains per cob, biological yield, grain yield and harvest index. Statistically maximum grain yield (8.76t ha-1) was obtained with foliar spray of ZnSO4 at 9-leaf stage (Zn2) in case of Monsanto-6525. Foliar spray of ZnSO4 increased 38% and soil application gave 23.7% more grain yield than control treatment. Foliar spray of ZnSO4 at 9-leaf stage in Monsanto-6525 hybrid produced higher grain yield and net field benefit. Thus foliar application of Zn fertilizers has a positive effect on economic and biological yield of maize crop.

Zinc enrichment in wheat genotypes under various methods of zinc application

Around half of the cereal growing soil in the world are zinc (Zn)-deficient and it severally affects the health of plants, animals and humans. In order to investigate the enrichment of Zn in cereals a pot experiment was conducted in two contrasting wheat genotypes viz., UP2628 (Zn efficient) and UP262 (Zn inefficient) under different meth ods of Zn application such as control (0 Zn), soil application (5 mg Zn/kg soil tagged with 3.7 MBq of 65 Zn/pot), foliar spray of 0.5% ZnSO 4 at 30, 60 and 90 days (tagged with 925 KBq of 65 Zn/pot), soil application (5 mg Zn/kg soil tagged with 3.7 MBq of 65 Zn/pot) + foliar spray of 0.5% ZnSO 4 at 30, 60 and 90 days (tagged with 925 KBq of 65 Zn/pot). Cultivars showed marked difference in 65 Zn accumulation and grain Zn content. In both contrasting genotypes the highest Zn content in grains was recorded under soil application + foliar spray of Zn fertilizers. Both UP262 and UP2628 showed similar accumulation of 65 Zn in leaves however, UP2628 exhibited better translocation efficiency and accumulated higher 65 Zn in stem and grains than UP262.

Responses of wheat to arbuscular mycorrhizal fungi: A meta-analysis of field studies from 1975 to 2013

Arbuscular mycorrhizal fungi (AMF) can benefit growth and yield of agriculturally significant crops by increasing mineral nutrient uptake, disease resistance and drought tolerance of plants. We conducted a meta-analysis of 38 published field trials with 333 observations to determine the effects of inoculation and root colonization by inoculated and non-inoculated (resident) AMF on P, N and Zn uptake, growth and grain yield of wheat. Field AMF inoculation increased aboveground biomass, grain yield, harvest index, aboveground biomass P concentration and content, straw P content, aboveground biomass N concentration and content, grain N content and grain Zn concentration. Grain yield was positively correlated with root AMF colonization rate, whereas straw biomass was negatively correlated. The most important drivers of wheat growth response to AMF were organic matter concentration, pH, total N and available P concentration, and texture of soil, as well as climate and the AMF species inoculated. Analysis showed that AMF inoculation of wheat in field conditions can be an effective agronomic practice, although its economic profitability should still be addressed for large-scale applications in sustainable cropping systems.

Effects of Application of Different Sources of Zn and Composts on Zn Concentration and Uptake by Upland Rice

Global efforts are under way to improve the Zn concentrations in rice to increase Zn in human diets. Therefore, this pot experiment was conducted to examine the effects of Zn sources and different composts on two upland rice varieties. This study was a 3 factors experiment with 3 replications arrange in RCBD. Experimental units include: 2 selected upland rice varieties with highest and lowest Zn uptake, 12 treatments, including 3 types of composts (oil palm compost, vermicompost and poultry compost) and 2 different sources of Zn (ZnS04 and Zn-EDTA). Soil samples were analyzed before and after harvest. The plants were harvested 16-20 weeks after planting and analysed. All types of composts showed positive effects on Zn concentration and uptake in all parts of rice. Vermicompost is the most effective compost among these three composts. Both inorganic Zn sources used showed almost the same Zn concentration and uptake by rice in this experiment. The magnitude of Zn uptake response was magnified when zinc sulphate was applied along with organic compost. Application of Zn-amended organic composts increased the percentage distribution of Zn in grain more than the application of ZnSO4 or Zn-EDTA alone.

Isolation and characterization of PGPR and their effect on growth, yield and nutrient content in wheat (Triticum aestivum L.)

Abstract The aims of our study were to enhance growth, yield and micronutrient status of wheat crop by various combinations of microbial strains (Bacillus megaterium, Arthrobacter chlorophenolicus and Enterobacter sp.) under pot and field experiments. Microbial strains were isolated from soils of different cropping systems and characterized by biochemical and molecular methods. Microbial strains (B. megaterium BHU1 and A. chlorophenolicus BHU3) showed positive result for nitrogen fixation and phosphate solubilization, while Enterobacter sp. BHU5 gave positive result in nitrogen fixation only. However, A. chlorophenolicus and Enterobacter sp. showed HCN production while B. megaterium and Enterobacter sp. gave siderophore. Maximum N2-fixation and IAA production were observed with 15.0 mg N g−1 carbon by A. chlorophenolicus and 26.4 µg ml−1 at tryptophan 100 µg ml−1 by Enterobacter sp, respectively. Triple combination of strains B. megaterium, A. chlorophenolicus and Enterobacter significantly increased 17.5%, 79.8%, 78.6% and 26.7% plant height, grain yield, straw yield and test weight under pot condition and also 29.4%, 27.5%, 29.5% and 17.6% under field condition, respectively. Similarly these treatment combinations showed maximum nutrient acquisition and content of micronutrient viz. Fe, Cu, Mn and Zn in grain of wheat under both conditions. The results showed that the combined application of indigenous PGPR, B. megaterium, A. chlorophenolicus and Enterobacter can be used as efficient microbial consortium for wheat production.

Effect of Phosphorus and Zinc Fertilizer Application to Increasing the Quality of Nourishment in Winter Wheat

Balanced fertilization is one of the most important factors for increasing yield and improving the quality of wheat crop. In human nutrition PA / Zn ratio is an important factor and nutrients absorption will be reduced by high levels of PA / Zn ratio in diet. Effect of Phosphorus and Zinc fertilizer application to increasing the quality of nourishment in winter wheat a field experiment was carried out from 2008 to 2009 in researching Karaj region. In a factorial experiment with a randomized complete block design and three replicates per treatment, tree levels of P (0, 100 and 200 kg.ha -1 as DAP), two levels of Zn (0 and 40 kg.ha -1 as zinc sulfate) and 300 kg.ha -1 urea fertilizer added to the trial plots. All other management practices were done in conventional methods. The seeds were Pishtaz variety that was planted. The Anova results showed that the effect of different rates of P and Zn on chemical characteristic of wheat grain was significant (P < 0.05). P and Zn increased the P and Zn grain concentration also increased grain protein and total grain nitrogen. The interactive effect of P and Zn on above characteristic was significant (P < 0.05) the best treatment in this study was obtained in Zn1P1. The effect of P on the PA/Zn ratio of grain was significant at 5% level and increased it (87.1%) but Zn application significantly (P < 0.05). As far the results of this study reveal that consumption of these two fertilizers it’s significant on flour pH and acidity. For reduction of PA / Zn ratios balanced and have a good quality wheat flour, fertilization especially Zn application and apply P fertilizers only on the basis of soil testing are necessary.

Effect of Genotype and Farming System on Concentration of Mineral Elements in Organically and Conventionally Grown Cereals/ Genotipa Un Saimniekoðanas Sistçmas Ietekme Uz Minerâlvielu Saturu Bioloìiski Un Konvencionâli Audzçtos Graudaugos

Abstract About half of the human population suffers from deficiency of mineral elements, mostly iron (Fe) and zinc (Zn). The purpose of the research was to compare the concentration of Fe and Zn in grain of 19 spring barley (in Hordeum vulgare L.) genotypes and the concentration of Zn and manganese (Mn) in grain of 19 winter wheat (Triticum aestivum L.) genotypes grown in organic and conventional management systems during two growing seasons. The average concentration of Fe in barley ranged from 32.51-86.85 mg·kg-1 and was higher under conventional management (p &lt; 0.001); the effect of genotype was significant (p = 0.014). The average concentration of Zn in barley ranged 16.79-48.51 mg·kg-1 and was significantly higher under the organic system (p &lt; 0.001); in wheat it was 21.52-29.89 mg·kg-1 with no difference between the management systems; the effect of genotype was significant (p = 0.03 and p &lt; 0.001 for barley and wheat, respectively). The average concentration of Mn in wheat ranged from 24.63-36.07 mg·kg-1 and was higher under the conventional system (p &lt; 0.001); significant differences between genotypes were observed (p &lt; 0.001). Barley and wheat genotypes with higher concentrations of the investigated elements were identified for use in breeding for improvement of grain quality. Zn concentration correlated negatively with grain yield and positively with grain protein concentration.

Micronutrient Density and Stability in West African Pearl Millet—Potential for Biofortification

ABSTRACTPearl millet [Pennisetum glaucum (L.) R. Br.] is one of the most important cereals in West and Central Africa (WCA). Human populations in WCA are strongly affected by micronutrient deficiencies. Biofortification, the development of pearl millet varieties with enhanced micronutrient levels, is recognized as a suitable approach to reducing this widespread health problem. To assess the potential of biofortification of WCA pearl millet germplasm, we studied quantitative‐genetic parameters of eight mineral densities in whole and decorticated grains, their stability over environments, and the correlations among minerals and agromorphological traits. The study included 72 WCA pearl millet genotypes grown in three environments in Niger, contrasting in soil fertilization. Significant genotypic effects, moderate estimates of heritability, and genetic variation for mineral densities, especially for Fe and Zn, indicate a high potential for biofortification of WCA pearl millet. However, screening of additional landraces or introgression of favorable alleles from highly nutrient‐dense Indian germplasm could expedite achievement of higher densities. Genotype‐by‐environment interaction effects were significant for Fe and Zn grain densities, showing the importance of multienvironmental evaluation for identifying stable genotypes. Identified genotypes with relatively stable Fe and Zn grain densities appear suitable for use in future WCA pearl millet biofortification breeding programs.

Effects of planting soybean in summer fallow on wheat grain yield, total N and Zn in grain and available N and Zn in soil on the Loess Plateau of China

Dryland wheat is the major contributor to wheat production in the world, where water deficiency and poor soil fertility are key factors limiting wheat grain yields and nutrient concentrations. A field experiment was carried out from June 2008 to June 2011 at Shilipu (latitude 35.12°N, longitude 107.45°E and altitude 1200m above sea level) on the Loess Plateau (a typical dryland) in China, to investigate the effects of rotation with soybean (Glycine max) green manure (GM) on grain yield, total N and total Zn concentrations in subsequent wheat (Triticum aestivum L.), and on nitrate-N and available Zn in the soil. The benefits of crop rotation with soybean GM on wheat grain yields became more evident with time. In the second and third years, the grain yields of wheat rotated with soybean GM reached 4871 and 5089kgha−1 at the 108kgNha−1 rate. These yields were 21% and 12% higher than the highest yields of wheat under a fallow-winter wheat (FW) rotation. Rotation with soybean GM reduced the amount of N fertilizer required to obtain wheat grain yields and biomass levels similar to wheat grown in the FW rotation by 20–33%. In the first 2 years, average grain N concentrations over all N rates increased by 6% and 12%, and those of Zn increased by 26% and 14% under the soybean GM-winter wheat (SW) rotation, compared with the FW rotation. The increased grain N and Zn concentrations were found to be related to the increased concentrations of nitrate-N and available Zn in the soil, particularly at the sowing of winter wheat. However, grain N and Zn concentrations were not improved by rotation with soybean GM in the third year. This was attributed to the dilution effect caused by the more grain yield increase than its nutrient export. In conclusion, planting soybean for GM in fallow fields reduced the need for N fertilizer to enhance wheat yields in this dryland region. Change in wheat grain N and Zn concentrations was related to soil nutrient concentrations, and to the balance between increased grain yield and its nutrient export.

Comparative Evaluation of Ground and Unground Pearl Millet and Sorghum Grain Samples for Determining Total Iron and Zinc

Rapid and effective methods are needed to analyze large numbers of grain samples for iron (Fe) and zinc (Zn) to select cultivars that are denser in these minerals. This study was conducted for the comparative evaluation of ground and unground grain samples for determining total Fe and Zn in pearl millet and sorghum cultivars with a range in seed size. In general, the results of the study with 50 pearl millet and 49 sorghum cultivars showed that grain Fe and Zn, in these relatively small-seeded crops, can be routinely determined using unground samples. Highly significant positive correlations were found between the values of Fe and Zn in grains of these crops determined using ground and ground samples.

Genotypic variation of zinc and selenium concentration in grains of Brazilian wheat lines

Exploration of genetic resources for micronutrient concentrations facilitates the breeding of nutrient-dense crops, which is increasingly seen as an additional, sustainable strategy to combat global micronutrient deficiency. In this work, we evaluated genotypic variation in grain nutrient concentrations of 20 Brazil wheat (Triticum aestivum L.) accessions in response to zinc (Zn) and Zn plus selenium (Se) treatment. Zn and Se concentrations in grains exhibited 2- and 1.5-fold difference, respectively, between these wheat accessions. A variation of up to 3-fold enhancement of grain Zn concentration was observed when additionally Zn was supplied, indicating a wide range capacity of the wheat lines in accumulating Zn in grains. Moreover, grain Zn concentration was further enhanced in some lines following supply of Zn plus Se, showing stimulative effect by Se and the feasibility of simultaneous biofortification of Zn and Se in grains of some wheat lines. In addition, Se supply with Zn improved the accumulation of another important micronutrient, iron (Fe), in grains of half of these wheat lines, suggesting a beneficial role of simultaneous biofortification of Zn with Se. The significant diversity in these wheat accessions offers genetic potential for developing cultivars with better ability to accumulate important micronutrients in grains.

Enrichment of &lt;sup&gt;65&lt;/sup&gt;Zn in two contrasting rice genotypes under varying methods of zinc application

Zinc (Zn) is an essential micronutrient for growth and development of almost all organisms and its deficiency severely affects the health of plants, animals and humans. In order to investigate the enrichment of Zn in cereals a pot experiment was performed in two contrasting rice varieties viz., PD16 (zinc efficient) and NDR359 (zinc inefficient) under different levels of zinc regimes such as control (0 Zn), soil application (5 mg Zn/kg soil tagged with 3.7 MBq of &lt;sup&gt;65&lt;/sup&gt;Zn/pot), foliar spray of 0.5% ZnSO&lt;sub&gt;4&lt;/sub&gt; at 30, 60 and 90 days (925 KBq of &lt;sup&gt;65&lt;/sup&gt;Zn/pot), soil application (5 mg Zn/kg soil tagged with 3.7 MBq of &lt;sup&gt;65&lt;/sup&gt;Zn/pot) + foliar spray of 0.5% ZnSO&lt;sub&gt;4&lt;/sub&gt; at 30, 60 and 90 days (925 KBq of &lt;sup&gt;65&lt;/sup&gt;Zn/pot). Both varieties markedly differ in &lt;sup&gt;65&lt;/sup&gt;Zn accumulation and grain Zn content. NDR359 showed poor translocation efficiency and accumulated relatively less &lt;sup&gt;65&lt;/sup&gt;Zn in all the plant parts. In both rice varieties, highest concentration of Zn in dehusked grains could be obtained with soil application of Zn + foliar spray of zinc sulphate. Though NDR359, a zinc inefficient variety exhibited poor zinc translocation efficiency yet, it contained more Zn content in grains with husk and dehusked grains than PD16.

Effects of nitrogen management on root morphology and zinc translocation from root to shoot of winter wheat in the field

Nitrogen (N) nutrition is a critical factor in root uptake and deposition of zinc (Zn) into wheat grain. However, little is known about how the root system in the soil profile responds to various N supplies under field conditions. A two-year field experiment was conducted to investigate the temporal and spatial distributions of winter wheat roots and relationships between root morphological traits and root Zn uptake with different N supplies. Results showed that an increasing N supply improved root length density (RL), surface area (RSA) and root dry weight (DW), thereafter, resulting in an increased root Zn uptake. For example, root Zn uptake significantly and positively correlated with RL, RSA and root DW at jointing (r=0.608*, 0.540* and 0.785***, respectively) and flowering (r=0.611*, 0.602* and 0.876***, respectively) stages. Furthermore, substantial root DW (80–92%) and root Zn uptake (85–96%) were mainly recovered from the upper 30cm of soil layer irrespective of N supply, showing a good spatial matching. The increased ratios of shoot-to-root Zn concentration and shoot-to-total Zn content with the increasing N supply indicate improving N supply promotes the root-to-shoot Zn transport and increases shoot Zn nutrition. Shoot Zn content was positively correlated with final grain yield and grain Zn concentration. Thus, a combination of optimum N supply with breeding for a better root system could be a promising approach to improve root uptake and accumulation of Zn in grain to maintain relatively higher grain Zn for human nutrition.