Zn Efficiency Research Articles

Enhancing the growth and zinc efficiency of cherry tomatoes by inoculating endophytic bacteria from zinc hyperaccumulator, Sedum alfredi Hance

Microbial biofertilizers, an innovative and eco-friendly strategy for nutritional improvement, could be utilized for zinc (Zn) efficiency and biofortification. Endophytic bacteria with Zn solubilizing and plant growth-promoting capacities were isolated from hyperaccumulator S. alfredi, and their impacts on the growth and Zn efficiency of cherry tomatoes under Zn-deficiency conditions were investigated. The results showed that most endophytic bacteria promoted the growth of tomato seedlings, while only specific endophytic bacteria played a role in Zn accumulation. Among them, inoculation with SaBA1, SaPS2, SaEN1, and SaPA1 not only significantly increased the fresh weight (FW) of tomato's young leaves by 3.1 to 3.6 times, but also raised the soil available Zn concentration by 0.58–0.92 mg/kg and improved the Zn accumulation in young leaves by 18 % to 30 %. The results indicated that these four bacteria could activate the availability of soil Zn, regulate the distribution of Zn in plants, and enable tomatoes to maintain healthy growth and development under Zn-deficiency conditions. This revealed their immense potential in enhancing crop yield, improving crop Zn nutrition, and boosting crop Zn efficiency.

Effect of zinc supplements on the nutritional status of different wheat genotypes

Zinc (Zn) plays a vital role in improving the quality of crops. It is more notable in terms of balanced nutrition, and alleviating inevitable side effects of unbalanced diet among developing nations. Hence, recently researchers have considered identifying Zn-efficient genotypes. The present study aimed to identify a zinc efficiency (ZnE) candidate among investigated genotypes. By conducting an experiment based on completely randomized design with two factors and four replications. The factors included two levels of Zn (0 and 10 mg Zn kg−1 soil derived from ZnSO4.7H2O) and nine different genotypes of wheat (Iraqi genotypes: Al-Rashid, Abu-Ghoraib, Latifiyeh, Tamuz 2, Bahus 22, Abba 95, Abba 99, and Iranian genotypes: HamoonZnE and Hirmandnon-ZnE). All plants were grown under similar experimental conditions for 90 days. Then the studied parameters comprised Zn, Mn, K, and P concentrations in grain, stem, leaf, and root of all genotypes were determined. In addition, to get a better understanding of Zn-efficiency (ZnE), two parameters including shoot Zn efficiency (SZnE) and Zn acquisition efficiency (ZnAE) were calculated. The results showed that Abba 95 and Hamoon genotypes were identified as the most Zn-efficient genotypes in which ZnE increased by 110% and 112%, respectively.

Seed-Primed and Foliar Oxozinc Nanofiber Application Increased Wheat Production and Zn Biofortification in Calcareous-Alkaline Soil

Low Zinc (Zn) availability in alkaline calcareous soil is one of the major causes of low cereal yield and quality. Conventional application of Zn sulfate (ZnSO4) fertilizer through soil application attains minimal Zn efficiency as it is readily fixed in such soils. Oxozinc nanofiber (ZnONF) was evaluated for wheat Zn biofortification using different application methods to tackle this issue. Pots in triplicate (each with 7 kg soil) were arranged in a completely randomized design with a control treatment without Zn application. The conventional ZnSO4 fertilizer recommended dose (5.5 µg Zn kg−1 of soil) was used for comparison and applied through soil addition, foliar spray, and seed priming, while the ZnONF was applied through foliar spray, seed coating, and seed priming (@ 0.5 kg ha−1) either alone or in combination with ½ZnSO4 applied to the soil. The application of ZnONF significantly improved wheat plant growth as evidenced by increased plant height (14.5%), spikelets per spike (13.7%), and Zn use efficacy (611%) regardless of application methods as compared to control. The highest Zn uptake efficiency (34%) for nanofibers was obtained for theseed primed, followed by seed coating (23%) and foiar application (7%), respectively. Moreover, at the combined ZnONF and ½ZnSO4 application, further improvements for spike length, number of spikelets spike−1, grain, leaf, root, and stem Zn concentrations, as well as their respective Zn contents, were noted. These results elucidated that Zn nutrition with ZnONF was either at par with or higher than the conventional ZnSO4 fertilizer application despite significantly reduced ZnONF quantity, irrespective of the application method used. Additionally, the combined ZnONF and ½ZnSO4 (foliar spray, seed coating, or seed priming) maximized the crop Zn accumulation, wherein the ½ZnSO4 + ZnONF through foliar application exceeded grain Zn biofortification. Thus, various Oxozinc nanofibers application modes may be recommended for wheat biofortification either separately or in combination with ZnSO4 in Zn deficient calcareous soils for improved Zn nourishment.

Unlocking the Potential of Zinc (Zn) Efficiency for Enhanced Crop Production in Low-Zn Environments

Approximately three billion people globally suffer from inadequate zinc (Zn) and iron (Fe) nutrition, leading to the deaths of 500,000 children. The trend towards healthier diets has heightened awareness of mineral nutrients like Zn, which is crucial for plant growth and plays a role in various processes like enzyme activation, chlorophyll synthesis, gene expression, signal transduction, and plant defense. Zn deficiency is a widespread problem, especially in alkaline soils, as these soils cannot meet the Zn needs of crops. To increase crop yield and growth, it is important to enhance plant Zn efficiency through improved Zn uptake, transport, and utilization. The cultivation of crops that demonstrate a strong ability to uptake and utilize zinc, such as rice, beans, wheat, soybeans, and maize, holds great potential for promoting sustainable food production and ensuring adequate nutrient intake. The objective of this review is to delve into crucial aspects of zinc efficiency in plants, such as the root system's ability to absorb zinc, the role of zinc transporters, and the utilization of zinc in the shoot, with the aim of enhancing the zinc content in crops and satisfying the growing demand for food globally. Future research will aim to identify the genes responsible for Zn efficiency and optimize phenotyping for the development of Zn-efficient crop varieties, ensuring food security for the future.

Zinc glycerolate (Glyzinc): A novel foliar fertilizer for zinc biofortification and cadmium reduction in wheat (Triticum aestivum L.)

Sustainable strategies are essential for zinc (Zn) biofortification and cadmium (Cd) reduction in staple food crops. Herein, we evaluated the phytotoxicity of Glyzinc under foliar and root application (FA&RA) in a lab-scale experiment, and then investigated its Zn efficiency and Cd reduction through foliar application on wheat (Triticum aestivum L.) under field conditions. Compared to RA, FA of Glyzinc exhibited no adverse effect on wheat growth and oxidative stresses at all doses. In field conditions, FA of Glyzinc remarkably increased Zn (28.7 %), S (10.4 %), Cu (17.3 %) and crude protein (9.1 %) content in wheat grain at 100 mg/L without damaging wheat yield. Furthermore, FA of Glyzinc significantly reduced the grain phytic acid (PA) (23.7 %) and Cd level (19.5 %), as well as PA to Zn molar ratio (32.3 %). Overall, our results indicate that Glyzinc has great potential as a high-efficiency foliar fertilizer for Zn biofortification and safe crop production in nano-enabled agriculture.

Characterization of zinc uptake and translocation visualized with positron-emitting 65Zn tracer and analysis of transport-related gene expression in two Lotus japonicus accessions.

Zinc (Zn) is an essential element for humans and plants. However, Zn deficiency is widespread and 25 % of the world's population is at risk of Zn deficiency. To overcome the deficiency of Zn intake, crops with high Zn content are required. However, most crop-producing areas have Zn-deficient soils, therefore crops with excellent Zn uptake/transport characteristics (i.e. high Zn efficiency) are needed. Our objective was to identify the crucial factors responsible for high Zn efficiency in the legume Lotus japonicus. We evaluated Zn efficiency by static and real-time visualization of radioactive Zn (65Zn) uptake/transport in two L. japonicus accessions, MG-20 and B-129, that differ in Zn efficiency. The combination of visualization methods verified the dynamics of Zn accumulation and transport within the plant. We compared gene expression under a normal Zn concentration (control) and Zn deficiency to evaluate genetic factors that may determine the differential Zn efficiency of the accessions. The accession B-129 accumulated almost twice the amount of Zn as MG-20. In the static 65Zn images, 65Zn accumulated in meristematic tissues, such as root tips and the shoot apex, in both accessions. The positron-emitting tracer imaging system (PETIS), which follows the transport process in real time, revealed that 65Zn transport to the shoot was more rapid in B-129 than in MG-20. Many genes associated with Zn uptake and transport were more highly expressed in B-129 than in MG-20 under the control condition. These gene expression patterns under Zn deficiency differed from those under the control Zn condition. PETIS confirmed that the real-time transport of 65Zn to the shoot was faster in B-129 than in MG-20. The high Zn efficiency of B-129 may be due to the elevated expression of a suite of Zn uptake- and transport-related genes.

Assaying the efficiency of sulfate, chelate and zinc nanoparticle fertilizers in green bean grown in alkaline soil

The excessive fertilizer application is a recurring problem in agriculture as it not only harms the soil texture but also diminishes the micronutrient availability i.e., zinc (Zn). Zn is an essential element for crop production and quality, and is also indispensable for human diet. Zn deficiency is a common problem in alkaline soils. This study aims to assess the efficiency of three different Zn fertilizers in Phaseolus vulgaris plants, grown in an alkaline soil. P. vulgaris plants were grown in an experimental greenhouse under four different treatments: control (no Zn fertilization), ZnSO4, the chelate diethylenetriaminepentaacetic acid (DTPA-Zn), and Zn nanoparticles (NfsZnO). Each Zn source was applied at three different doses (0, 25, 50, 100 mg kg−1). Parameters related to biomass, photosynthetic pigments, and Zn accumulation were analyzed. Zn sources enhanced bean pod growth and yield. Furthermore, the three Zn sources increased Zn accumulation in all plant organs, except in leaves. Whereas, plants supplied with 100 mg kg−1 of DTPA-Zn and 25 mg kg−1 of NfsZnO accumulated the highest bean Zn concentration. Generally, plants supplied with DTPA-Zn and NfsZnO showed the highest Zn content values. Besides, Zn sources enhanced the values of Zn efficiency parameters in a dose-dependent manner. According to the results, the three Zn fertilizers were effective to increase the parameters analyzed in P. vulgaris. However, DTPA-Zn and NfsZnO were more effective to enhance yield and bean Zn content, and thus can be useful for bean cultivation in alkaline soils.

Rice cv. HUR105 response to zinc fertilizer combined with microbial consortia and cow dung grown in the eastern plain of Uttar Pradesh, India

The solubility and bioavailability of zinc in the soil determinethe efficiency of Zn fertilizers. A two-year (2018 and 2019) field experiment was performed to study the effectiveness of Zn sources combined with Zn solubilizing microorganisms, ZSM (Acinetobacter calcoaceticus + Pantoea agglomerans) and cow dung, in rice cv. HUR105 in alluvial soil at the Agriculture Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh. Among various treatments, the treatment (T8) 9.8 kg ZnO ha-1 with ZSM showed better grain and straw yields. However, 25.0 kg ZnSHH ha-1+ ZSM (T6) was found to be statistically comparable to the treatment (T8). The addition of cow dung (CD) decreased the grain yield in T11 ( 9.8 kg ZnO ha-1 + ZSM + 200 kg CD ha-1) and T12 (14.6 kg ZnO ha-1 + ZSM + 200 kg CD ha-1), except the treatment (T10) 4.9 kg ZnO + ZSM + 200 kg CD ha-1. Partial factor productivity of applied Zn varied from 347.2 to 1762.2 and 369.6 to 1855.6 kg grain kg-1 Zn, physiological Zn efficiency varied from 487.4 to 2075.3 and 775.5 and 2035.2 kg grain kg-1 Zn absorbed, agronomic use efficiency of Zn ranged from 20.1 to 189.6 and 28.7 to 180 kg grain kg-1 Zn, the recovery efficiency of Zn fertilizer varied from 3.58 to 11.9% and 3.57 to 11.8% among the treatments in both seasons, respectively. The maximum gross and net return were documented by T8- 9.8 kg ZnO ha-1 + ZSM, and 23.9% and 28.5% over the control due to higher grain yields.

Identification and Analysis of Zinc Efficiency-Associated Loci in Maize.

Zinc (Zn) deficiency, a globally predominant micronutrient disorder in crops and humans, reduces crop yields and adversely impacts human health. Despite numerous studies on the physiological mechanisms underlying Zn deficiency tolerance, its genetic basis of molecular mechanism is still poorly understood. Thus, the Zn efficiency of 20 maize inbred lines was evaluated, and a quantitative trait locus (QTL) analysis was performed in the recombination inbred line population derived from the most Zn-efficient (Ye478) and Zn-inefficient inbred line (Wu312) to identify the candidate genes associated with Zn deficiency tolerance. On this basis, we analyzed the expression of ZmZIP1-ZmZIP8. Thirteen QTLs for the traits associated with Zn deficiency tolerance were detected, explaining 7.6–63.5% of the phenotypic variation. The genes responsible for Zn uptake and transport across membranes (ZmZIP3, ZmHMA3, ZmHMA4) were identified, which probably form a sophisticated network to regulate the uptake, translocation, and redistribution of Zn. Additionally, we identified the genes involved in the indole-3-acetic acid (IAA) biosynthesis (ZmIGPS) and auxin-dependent gene regulation (ZmIAA). Notably, a high upregulation of ZmZIP3 was found in the Zn-deficient root of Ye478, but not in that of Wu312. Additionally, ZmZIP4, ZmZIP5, and ZmZIP7 were up-regulated in the Zn-deficient roots of Ye478 and Wu312. Our findings provide a new insight into the genetic basis of Zn deficiency tolerance.

Development of molecular markers lınked to QTL/genes controllıng Zn effıcıency.

Zinc (Zn) deficiency is a widespread problem in reducing the yield and quality of crop plants worldwide. It is important to utilize molecular markers linked to Zn efficiency to develop high Zn efficient cultivars in pepper (Capsicum annuum L.). In present study, genetic map was constructed using a F2 populations derived from C. annuum L. (Alata 21A) × C. frutescens L. (PI 281420) cross. The quantitative trait locus (QTLs) for Zn efficiency were mapped using F2:3 population. A genetic map with 929.6cM in length and 12 linkage groups were obtained using 62 markers (31 sequence-related amplified polymorphism (SRAP), 19 simple sequence repeat (SSR) and 11 random amplified polymorphic DNA (RAPD) markers). The 41 linked QTLs related with nine (9) Zn efficiency characters were mapped on linkage groups. Results suggest that selecting plants for tolerance to Zn deficiency are expected to be rather responsive among segregating populations for breeding and developing Zn efficient genotypes in pepper. The molecular markers are expected to aid selection and expedite breeding peppers resistant to Zn deficiency in soils low for available Zn contents.

Maize Genotypes With Different Zinc Efficiency in Response to Low Zinc Stress and Heterogeneous Zinc Supply.

All over the world, a common problem in the soil is the low content of available zinc (Zn), which is unevenly distributed and difficult to move. However, information on the foraging strategies of roots in response to heterogeneous Zn supply is still very limited. Few studies have analyzed the adaptability of maize inbred lines with different Zn efficiencies to different low Zn stress time lengths in maize. This study analyzed the effects of different time lengths of low Zn stress on various related traits in different inbred lines. In addition, morphological plasticity of roots and the response of Zn-related important gene iron-regulated transporter-like proteins (ZIPs) were studied via simulating the heterogeneity of Zn nutrition in the soil. In this report, when Zn deficiency stress duration was extended (from 14 to 21 days), under Zn-deficient supply (0.5 μM), Zn efficiency (ZE) based on shoot dry weight of Wu312 displayed no significant difference, and ZE for Ye478 was increased by 92.9%. Under longer-term Zn deficiency, shoot, and root dry weights of Ye478 were 6.5 and 2.1-fold higher than those of Wu312, respectively. Uneven Zn supply strongly inhibited the development of some root traits in the -Zn region. Difference in shoot dry weights between Wu312 and Ye478 was larger in T1 (1.97 times) than in T2 (1.53 times). Under heterogeneous condition of Zn supply, both the –Zn region and the +Zn region upregulated the expressions of ZmZIP3, ZmZIP4, ZmZIP5, ZmZIP7, and ZmZIP8 in the roots of two inbred lines. These results indicate that extended time length of low-Zn stress will enlarge the difference of multiple physiological traits, especially biomass, between Zn-sensitive and Zn-tolerant inbred lines. There were significant genotypic differences of root morphology in response to heterogeneous Zn supply. Compared with split-supply with +Zn/+Zn, the difference of above-ground biomass between Zn-sensitive and Zn-tolerant inbred lines under split-supply with –Zn/+Zn was higher. Under the condition of heterogeneous Zn supply, several ZmZIP genes may play important roles in tolerance to low Zn stress, which can provide a basis for further functional characterization.

Zn Ferti-fortification of Wheat (Triticum Aestivum L.) Using Zinc Enriched Compost and Biochar in Rainfed Area

ABSTRACT Zinc deficiency is a global nutritional problem which is caused by low dietary intake. Wheat is mostly low in bioavailable Zn and is sensitive to zinc deficiency compared with other grain crops and as a result is reflected as cereal with low Zn efficiency. Zn deficiency prevails in arid to semiarid regions of the world for reasons of less solubility and more fixation of Zn in these soil conditions. Biofortification is currently one of the useful approaches to overcome worldwide malnourishment. A pot and two years field trials were conducted on wheat crop with following treatments: control, Zn @ 3 mg kg−1, Zn @ 6 mg kg−1, Zn @ 9 mg kg−1, Compost @ 20 t ha−1, Zn-enriched compost @ 3 mg kg−1, Zn-enriched compost @ 6 mg kg−1, Zn-enriched compost @ 9 mg kg−1, Biochar @ 20 t ha−1, Zn-enriched biochar @ 3 mg kg−1, Zn-enriched biochar @ 6 mg kg−1 and Zn-enriched biochar @ 9 mg kg−1 and treatments for field trial: control, Zn @ 18 kg ha−1, Compost @ 20 t ha−1, Zn-enriched compost @ 18 kg ha−1, Biochar @ 20 t ha−1 and Zn-enriched biochar @ 18 kg ha−1. Results of field trial revealed that maximum grain Zn (29.18 mg kg−1) recorded in Zn-enriched compost @ 9 mg kg−1 and minimum (17.8 mg kg−1) was in control. It is concluded that Zn-enriched organic amendments especially compost found to be appropriate for yield of wheat crop and grain Zn biofortification of wheat that in result increased protein contents and reduced phytic acid concentration.

424 WS Young Scholar Talk PHD: Effect of increasing dietary zinc during late gestation and early lactation on ewe and lamb body weights, serum and milk minerals, and somatic cell count

Abstract The objectives of the current research are to quantify the effects that increased dietary Zn during late gestation and early lactation has on ewe and progeny body weights, serum and milk minerals, and somatic cell count. Within Rambouillet (WF) and Hampshire (BF) breeds, ewes were ranked by BW and randomly assigned down the rank into 1 of 2 treatment groups: Control (n = 34, 37 mg Zn/kg DM, ≈1×NRC) and Zn treatment (n = 37, 113 mg Zn/kg DM, ≈3×NRC). Treatments were delivered via a ZnSO4-fortified alfalfa pellet fed at a rate of 0.45 kg/d DM from a RFID-activated automated feeder from d 108 ± 10 of gestation to d 30 post-lambing. Ewe BW were recorded at d 0, 29, lambing, 30 post-lambing, and weaning. Lamb BW was recorded at lambing, d 15, 30, and weaning. Serum samples were taken from ewes and lambs at 18 ± 4 h post-lambing and analyzed for mineral concentrations. Maternal trace mineral transfer efficiency were calculated by dividing lamb serum values by their respective dam’s serum value and expressed as a percentage. Ewe milk was collected twice weekly. Milk was analyzed for mineral content (d 0, 10, and 30 of lactation) and SCC (d 3–5, 6–9, 10–12, 13–16, 17–19, 20–23, 24–26, 27–29, or 30–32). Ewe and lamb BW was not influenced by Zn treatment (P > 0.19). Ewe serum Zn and maternal transfer efficiency did not differ between control and Zn treatment ewes (P ≥ 0.47). There was a treatment × breed type interaction for lamb serum LogZn (P = 0.04), where BF lambs within Zn treatment had greater serum LogZn (0.63 ± 0.32) than WF lambs (-0.37 ± 0.27; P = 0.04), but breeds did not differ within lambs in the Control treatment group. Milk Ni and Zn was greater for Zn treated ewes than control ewes (P < 0.01), but Mg and P concentrations were greater for control ewes (P ≤ 0.02). Control and Zn treated ewes did not differ in LogSCC through the first 30 d of lactation (P = 0.68) nor did they differ at weaning (P = 0.48). White face and BF ewes LogSCC did not differ at weaning (P = 0.09), but for the first 30 d of lactation BF (5.79 ± 0.06) had greater LogSCC than WF ewes (5.54 ± 0.06; P < 0.01). Day of lactation impacted ewe SCC (P < 0.01), with peak SCC between d 6 and 9 which began to decline as lactation progressed. Current Zn recommendations appear to be adequate for ewe and lamb growth during late gestation and early lactation, but results suggest litter size and breed nuances. Milk Zn is also increased with dietary Zn above NRC recommendations, while further interactions with milk Ni, Mg, and P occur. Additionally, longitudinal values of SCC throughout lactation may inform preventative intervention strategies for cases of sub-clinical mastitis since peak SCC is within the first 9 d post-lambing.

Zinc (Zn): The Last Nutrient in the Alphabet and Shedding Light on Zn Efficiency for the Future of Crop Production under Suboptimal Zn.

At a global scale, about three billion people have inadequate zinc (Zn) and iron (Fe) nutrition and 500,000 children lose their lives due to this. In recent years, the interest in adopting healthy diets drew increased attention to mineral nutrients, including Zn. Zn is an essential micronutrient for plant growth and development that is involved in several processes, like acting as a cofactor for hundreds of enzymes, chlorophyll biosynthesis, gene expression, signal transduction, and plant defense systems. Many agricultural soils are unable to supply the Zn needs of crop plants, making Zn deficiency a widespread nutritional disorder, particularly in calcareous (pH > 7) soils worldwide. Plant Zn efficiency involves Zn uptake, transport, and utilization; plants with high Zn efficiency display high yield and significant growth under low Zn supply and offer a promising and sustainable solution for the production of many crops, such as rice, beans, wheat, soybeans, and maize. The goal of this review is to report the current knowledge on key Zn efficiency traits including root system uptake, Zn transporters, and shoot Zn utilization. These mechanisms will be valuable for increasing the Zn efficiency of crops and food Zn contents to meet global needs for food production and nutrition in the 21st century. Furthermore, future research will address the target genes underlying Zn efficiency and the optimization of Zn efficiency phenotyping for the development of Zn-efficient crop varieties for more sustainable crop production under suboptimal Zn regimes, as well food security of the future.

Classification of Pigeonpea (Cajanus cajan (L.) Millsp.) Genotypes for Zinc Efficiency.

Pigeonpea (Cajanus cajan (L.) Millsp.) is grown globally for its protein-rich seed. However, low availability of soil zinc (Zn) adversely affects the seed yield of pigeonpea. The present study was therefore conducted to assess the Zn efficiency of pigeonpea genotypes based on seed yield and seed Zn uptake efficiency. Field experiments were conducted at the Indian Council of Agricultural Research–Indian Institute of Soil Science, Bhopal, India with twenty different pigeonpea genotypes and two levels of Zn application under a split-plot design. The two levels of Zn were low (without application of Zn fertilizer) and high (with application of 20 kg Zn ha−1 (as ZnSO4∙7H2O) as basal soil application, in conjunction with three foliar sprays of 0.50% (w/v) ZnSO4∙7H2O aqueous solution) (with 0.25% lime as neutralizing agent) at flowering, pod formation, and pod filling stages). Application of Zn improved plant height, branches plant−1, pods plant−1, seeds pod−1, and 100 seed weight of pigeonpea genotypes differently. The mean seed yield, seed Zn concentration, and seed Zn uptake of the genotypes increased from 1.71 to 2.12 t ha−1, 32.4 to 43.0 mg kg−1, and 54.9 to 90.6 g ha−1, respectively, with application of Zn. The seed yield efficiency index (SYEI) and Zn uptake efficiency index (ZUEI) of pigeonpea genotypes varied from 67.0 to 92.5 and from 47.0 to 69.9, respectively. Based on SYEI and ZUEI, the genotypes were classified as efficient and responsive (Virsa Arhar-1, GT-1, GT-101, SKNP 05-05, BDN-2, AAUT 2007-04, BSMR 853, T 15-15, DT 23, Pusa 9), efficient and non-responsive (ICPL 87119, PKV Trombay), inefficient and responsive (AKT 8811, Hisar Paras), and inefficient and non-responsive (AAUT 2007-10, JKM 7, Hisar Manak, C 11, Hisar HO2-60, GAUT 93-17). The efficient and responsive genotypes are the most useful as they yield well under low soil Zn conditions and also respond to Zn fertilizer application. The inefficient and responsive genotypes could be utilized for plant breeding programs by plant breeders for identification and utilization of responsive traits.

Field evaluation of Zincated nanoclay polymer composite (ZNCPC): Impact on DTPA-extractable Zn, sequential Zn fractions and apparent Zn recovery under rice rhizosphere

Zinc (Zn) deficiency is a widespread phenomenon globally. Conventional Zn fertilizers (ZnSO4·7H2O) are reported to have very low use efficiency of applied Zn (1–5%). Hence, technological interventions in increasing Zn efficiency are of utmost importance. Keeping in this background, the present investigation was undertaken with the objectives of evaluating ZNCPC (Zincated nanoclay polymer composites), Nano ZnO and ZnSO4·7H2O on various fractions of soil Zn and agronomic parameters under rice rhizosphere in field experiment for two consecutive growing seasons. Nano Zn carriers (ZNCPC at three doses 100%, 75% and 50%) and nano ZnO were evaluated in comparison with ZnSO4·7H2O in a field experiment under rice (Rajendra Mahsuri) rhizosphere. DTPA Zn was significantly increased under 100% ZNCPC (1.99 mg kg−1). Sequential Zn fractionation revealed that under ZNCPC treatments there was significant increase of water soluble, exchangeable and organically bound Zn, whereas there was significant increase of residual and specifically adsorbed Zn under ZnSO4·7H2O. Grain Zn content was maximum under 100% ZNCPC treatment (40.57 mg kg−1) followed by nano ZnO (34.71 mg kg−1). Maximum AZR (Apparent Zn recovery) was found in case of 100% ZNCPC (26.35%) followed by 75% ZNCPC (21.22%) and nano ZnO (18.73%). ZNCPC was found to be promising Zn formulation for increasing Zn use efficiency. Nano ZnO at foliar spray was also proved to be effective in increasing the grain Zn concentration. However, ZNCPC and nano ZnO need to be evaluated in long-term experiment in various soil types and cropping system for evaluating benefit: cost ratio and wide scale farmers’ adaptability.

Screening of rice (Oryza sativa L.) genotypes for zinc efficiency in Inceptisols of Odisha

Zinc deficiency in crop has been recognized as world wise nutritional constraint. Zinc is important micronutrient for plant growth and nutrition of human being. Short supply of zinc to crops yield results in low concentration in grain for which malnutrition of human being occurs, those depends on rice based diet mainly in developing countries. Growing zinc efficient cultivars represent long term solution for sustainable approach to crop production. Twenty diverse rice genotypes were tested in a field experiment of Inceptisols of Odisha, at three levels of Zn (0,20kgha-1 and 20kgha-1 +0.5% ZnSO4 sprayed twice at pre-flowering and booting stage) with the objective of developing a screening technique to evaluate the rice genotypes for zinc use efficiency. Genotypes differed significantly in grain yield. Grain yield efficiency Index is the best tools to categorize the genotypes into efficient and non-efficient groups. The relative grain yield ie. Zn efficiency index from 96.7 to 76.2 percent and relative grain Zn uptake ie. Zn efficiency from 91.4 to 68.3% among the genotypes. On the basis of grain yield and Zn efficiency, genotypes are classified on efficient and responsive (Swarna, IR 64,Vanaprava, Lalata, Gajapati and Ranidhan), efficient and non responsive (Prachi, Samba masuri, Kharbela, Sarala, Monoswani, Swarna masuri and Jajati), Inefficient and responsive (Birupa, Banki and CR1030), Inefficient and non responsive (IR 36, Suphala, Ghanteswari and Rudra). From practical point of view, genotypes that produce high grain yield at low level of Zn and responsive well to Zn addition are most desirable because they able to express their high potential in a wide range of Zn availability.

Response of rice genotypes under different zinc fertilization strategy

Soil zinc (Zn) deficiency limits crop growth and yield besides its low concentration in grain and straw. Growing of Zn efficient cultivars with high crop yield at low Zn supply would represent a sustainable approach to crop production. Therefore, to evaluate Zn efficiency of rice genotypes, twenty eight different rice genotypes were evaluated under various treatments like three levels of Zn viz. low (without Zn), medium (10 kg Zn ha-1 soil) and high (20 kg Zn ha-1 soil + three foliar sprays of 0.5% Zn). Zinc efficiency index of all genotypes ranged from 65.5 to 102.6 % and Zn uptake efficiency ranged from 53.8 to 107 % with a mean value of 87.1 and 76.5 %. Cultivar GR-101 was having the highest Zn efficiency index as well as Zn efficiency compared to other genotype. Based on grain yield and Zn efficiency, the genotypes Ashoka-20, Narmad, GR-12, GR-3, GR-1 and GR-2 were classified as efficient and responsive, genotypes GR- 11, SLR -51214. GAUR-10 and GR-13 as efficient and non responsive, whereas, genotypes GR-101, GR-104, GR-102 and Lalkad as inefficient and responsive. The Gurjari, AAUDR-1, K-Kamod, GR-9, GR-5, P-2003 SK-20 and GR-7 genotype were classified as inefficient and non responsive. The efficient and responsive genotypes are most desirable as they would produce higher yield under low Zn concentration in soil and responded well under external application of Zn sources.

Effect of zinc on N, P, K and Zn concentration, uptake and Zn efficiency in rice

Effect of zinc on N, P, K and Zn concentration, uptake and Zn efficiency in rice

Supra‐optimal growth temperature exacerbates adverse effects of low Zn supply in wheat

AbstractRising temperatures are a major threat to global wheat production, particularly when accompanied by other abiotic stressors such as mineral nutrient deficiencies. This study aimed to quantify the effects of supra‐optimal temperature on growth, photosynthetic performance, and antioxidative responses in bread wheat cultivars grown under varied zinc (Zn) supply. Two bread wheat cultivars (Triticum aestivum L., cvs. Lasani‐2008 and Faisalabad‐2008) with varied responsiveness to Zn supply and drought tolerance were cultured in nutrient solution with low (0.1 µM) or adequate (1.0 µM) Zn under optimal (25/20°C day/night) or supra‐optimal (36/28°C day/night) temperature regimes. Supra‐optimal temperature severely reduced root but not shoot biomass, whereas low Zn reduced shoot as well as root biomass. Shoot‐to‐root biomass ratio was reduced under low Zn but increased under supra‐optimal temperature. Supra‐optimal temperature inhibited root elongation and volume particularly in plants supplied with low Zn. In both cultivars, Zn efficiency index was reduced by supra‐optimal temperature, whereas heat tolerance index was reduced by low Zn supply. Supra‐optimal temperature decreased photosynthesis, quantum yield, and chlorophyll density in low‐Zn but not in adequate‐Zn plants. In comparison, low Zn decreased specific activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) and increased glutathione reductase (GR), where supra‐optimal temperature increased SOD, decreased GR and did not change APX activity in leaves and roots. Moreover, supra‐optimal temperature severely reduced shoot Zn concentration and Zn uptake per plant specifically under adequate Zn supply. Overall, supra‐optimal temperature exacerbated adverse effects of low Zn supply, resulting in severe reductions in growth traits viz. shoot and root biomass, root length and volume, and consequently impeded Zn uptake, enhanced oxidative stress and impaired photosynthetic performance. Adequate Zn nutrition is crucial to prevent yield loss in wheat cultivated under supra‐optimal temperatures.