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1.
Brassica rapa L. is an important vegetable crop in eastern Asia. The objective of this study was to investigate the genetic variation in
leaf Zn, Fe and Mn accumulation, Zn toxicity tolerance and Zn efficiency in B. rapa. In total 188 accessions were screened for their Zn-related characteristics in hydroponic culture. In experiment 1, mineral
assays on 111 accessions grown under sufficient Zn supply (2 μM ZnSO 4) revealed a variation range of 23.2–155.9 μg g −1 dry weight (d. wt.) for Zn, 60.3–350.1 μg g −1 d. wt. for Fe and 20.9–53.3 μg g −1 d. wt. for the Mn concentration in shoot. The investigation of tolerance to excessive Zn (800 μM ZnSO 4) on 158 accessions, by using visual toxicity symptom parameters (TSPs), identified different levels of tolerance in B. rapa. In experiment 2, a selected sub-set of accessions from experiment 1 was characterized in more detail for their mineral accumulation
and tolerance to excessive Zn supply (100 μM and 300 μM ZnSO 4). In this experiment Zn tolerance (ZT) determined by relative root or shoot dry biomass varied about 2-fold. The same six
accessions were also examined for Zn efficiency, determined as relative growth under 0 μM ZnSO 4 compared to 2 μM ZnSO 4. Zn efficiency varied 1.8-fold based on shoot dry biomass and 2.6-fold variation based on root dry biomass. Zn accumulation
was strongly correlated with Mn and Fe accumulation both under sufficient and deficient Zn supply. In conclusion, there is
substantial variation for Zn accumulation, Zn toxicity tolerance and Zn efficiency in Brassica rapa L., which would allow selective breeding for these traits. 相似文献
2.
This study, comprising three independent experiments, was conducted to optimize the zinc (Zn) application through seed coating for improving the productivity and grain biofortification of wheat. Experiment 1 was conducted in petri plates, while experiment 2 was conducted in sand-filled pots to optimize the Zn seed coating using two sources (ZnSO 4, ZnCl 2) of Zn. In the first two experiments, seeds of two wheat cultivars Lasani-2008 and Faisalabad-2008 were coated with 0.25, 0.50, 0.75, 1.00, 1.25, 1.50, 1.75 and 2.00 g Zn kg ?1 seed using ZnSO 4 and ZnCl 2 as Zn sources. The results of experiment I revealed that seed coating with 1.25 and 1.50 g Zn kg ?1 seed using both sources of Zn improved the seedling emergence. However, seed coated with 1.25 and 1.50 g Zn kg ?1 seed using ZnSO 4 was better regarding improvement in seedling growth and seedling dry weight. The results of the second experiment indicated that seed coated with 1.25 and 1.50 g Zn kg ?1 seed using ZnSO 4 improved the seedling emergence and seedling growth of tested wheat cultivars. However, seed coating beyond 1.5 g Zn kg ?1 seed using either Zn source suppressed the seedling emergence. Third experiment was carried out in glass house in soil-filled earthen pots. Seeds of both wheat cultivars were coated with pre-optimized treatments (1.25, 1.50 g Zn kg ?1 seed) using both Zn sources. Seed coating with all treatments of ZnSO 4 and seed coating with 1.25 g Zn kg ?1 seed using ZnCl 2 improved the seedling emergence and yield-related traits of wheat cultivars. Seed coating with 1.25 g Zn kg ?1 seed also improved the chlorophyll a and b contents. Maximum straw Zn contents, before and after anthesis, were recorded from seed coated with 1.5 g Zn kg ?1 seed using either Zn source. Increase in grain yield from seed coating followed the sequence 1.25 g Zn kg ?1 seed (ZnSO 4) >1.25 g Zn kg ?1 seed (ZnCl 2) >1.5 g Zn kg ?1 seed (ZnSO 4). However, increase in grain Zn contents from seed coated was 1.5 g Zn kg ?1 seed (ZnCl 2) >1.25 and 1.5 g Zn kg ?1 seed (ZnCl 2, ZnSO 4) >1.25 g Zn kg ?1 seed (ZnSO 4). Seed coating with Zn increased the grain Zn contents from 21 to 35 %, while 33–55 % improvement in grain yield was recorded. In conclusion, wheat seeds may be coated with 1.25 g Zn kg ?1 seed using either source of Zn for improving the grain yield and grain Zn biofortification. 相似文献
3.
Summary A greenhouse experiment conducted to study the effect of different levels of Zn supplied through Zn-amended poultry manure and ZnSO 4 on corn ( Zea mays L.) indicated that both the sources significantly increased the dry matter yield and uptake of zinc. The zinc amended poultry manure at all levels of zinc application was more effective than ZnSO 4 in this respect. The percent zinc in corn derived from the fertilizer and percent utilization of applied zinc from the Zn-amended poultry manure was higher than that from ZnSO 4 when applied at equivalent levels. 相似文献
4.
为探讨Zn、B配施对鸡血藤(Spatholobus suberectus)黄酮类化合物积累的影响,采用营养液叶面喷施,对其总黄酮含量、可溶性蛋白质和PAL活性的变化进行研究。结果表明,Zn、B配施的鸡血藤总黄酮含量、可溶性蛋白质含量、PAL活性增加,其中施用50 mg L–1 Zn SO4+10 mg L–1 Na_2B_4O_7·10H_2O鸡血藤的可溶性蛋白质含量最高,达0.89%;施用25 mg L–1Zn SO4+50 mg L–1 Na2B4O7·10H2O鸡血藤的总黄酮含量和PAL活性最高,分别为4.65%、29.47 U g–1min–1。因此,合理配施Zn、B能促进鸡血藤黄酮类化合物的积累。 相似文献
5.
Using two bread wheat ( Triticum aestivum) and two durum wheat ( Triticum durum) cultivars differing in zinc (Zn) efficiency, uptake and translocation of foliar-applied 65Zn were studied to characterize the role of Zn nutritional status of plants on the extent of phloem mobility of Zn and to determine the relationship between phloem mobility of Zn and Zn efficiency of the used wheat cultivars. Irrespective of leaf age and Zn nutritional status of plants, all cultivars showed similar Zn uptake rates with application of 65ZnSO 4 to leaf strips in a short-term experiment. Also with supply of 65ZnSO 4 by immersing the tip (3 cm) of the oldest leaf of intact plants, no differences in Zn uptake were observed among and within both wheat species. Further, Zn nutritional status did not affect total uptake of foliar applied Zn. However, Zn-deficient plants translocated more 65Zn from the treated leaf to the roots and remainder parts of shoots. In Zn-deficient plants about 40% of the total absorbed 65Zn was translocated from the treated leaf to the roots and remainder parts of shoots within 8 days while in Zn-sufficient plants the proportion of the translocated 65Zn of the total absorbed 65Zn was about 25%. Although differences in Zn efficiency existed between the cultivars did not affect the translocation and distribution of 65Zn between roots and shoots. Bread wheats compared to durum wheats, tended to accumulate more 65Zn in shoots and less 65Zn in roots, particularly under Zn-deficient conditions. The results indicate that differences in expression of Zn efficiency between and within durum and bread wheats are not related to translocation or distribution of foliar-applied 65Zn within plants. Differential compartementation of Zn at the cellular levels is discussed as a possible factor determining genotypic variation in Zn efficiency within wheat. 相似文献
6.
The effects of CaCO 3, Zn sources and levels on the yield of submerged paddy and uptake of Zn, P and N to paddy were studied in green-house at Haryana Agricultural University, Hissar. Powdered CaCO 3 was mixed at 0,4 and 8 per cent and Zn was added at 0,5 and 10 ppm through ZnSO 4.7H 2O, ZnO and Zn EDTA separately. Dry weight at tillering and heading and grain and straw at maturity decreased significantly with 4 and 8 per cent CaCO 3 in comparison to the control. Increasing Zn application increased the dry weight and grain yield. Zn EDTA gave highest yield of paddy followed by ZnSO 4.7H 2O and ZnO.Increasing the application of CaCO 3 from 0–8 per cent decreased the concentration and uptake of Zn and increasing Zn application from 0–10 ppm increased concentration and uptake of Zn in paddy at tillering, heading and maturity. Zn EDTA gave the highest concentration and uptake of Zn followed by ZnSO 4.7H 2O and ZnO. There was interaction between Zn sources and CaCO 3.The concentration and uptake of N and P in paddy dry matter at tillering and heading and straw and grain at maturity decreased as compared to control with increasing CaCO 3 addition. The concentration and uptake of N increased and that of P decreased in paddy dry matter straw and grain with increasing Zn application. The highest concentration of N was observed with ZnO, followed by ZnSO 4.7H 2O and Zn EDTA. But highest uptake of N was observed with Zn EDTA followed by ZnSO 4.7H 2O and ZnO. As regards concentration and uptake of P, it was highest with ZnO followed by ZnSO 4.7H 2O and Zn EDTA. 相似文献
7.
Micronutrient nanoparticles (NPs) are currently an option for chemical fertilization and biostimulation in crops. However, there is little information on the phytotoxic or biostimulatory effects of NPs at low concentrations of some elements, such as Zn. In this study, the effect of low concentrations of Zn oxide (ZnO) NPs on germination, growth variables, and nutritional attributes of lettuce (Lactuca sativa L.) was evaluated in comparison to Zn sulfate. Romaine lettuce seeds were treated with ZnSO4-- × 7H2O and ZnO NPs at Zn molar concentrations of 1 × 10−3, 5 × 10−3, 1 × 10−4, 5 × 10−4, 1 × 10−5, 5 × 10−5, 1 × 10−6, and 5 × 10−6. The seeds treated with ZnSO4− at 5 × 10−6 registered the highest radicle length, 73% more than the control treatment. The seeds treated with ZnSO4− at 5 × 10−3 registered the lowest values, with 50% less than the control treatment. ZnO NPs at 5 × 10−6 significantly increased content of chlorophyll A and B and total phenolics. These results indicate the possible existence of a mechanism related to the intrinsic nanoparticle properties, especially at low concentrations. 相似文献
8.
Zinc is an essential nutrient that plays an important role in several biological processes of living organisms. When bound to an organic substrate, Zn is more efficiently absorbed by organisms, has a high biological activity and a low toxicity. Due to its ability to incorporate metals, yeast biomass has been used frequently as a delivery vehicle for many mineral supplements. This study describes the screening of strains of yeast for production of biomass enriched with Zn by submerged fermentation. Five strains of yeasts, belonging to the genera Saccharomyces, Kluyveromyces and Pichia, were evaluated. The highest Zn concentration was 6820 mg/kg of dry weight biomass, using Pichia guilliermondii Wickerham LPB 063 after 120 h of cultivation in a medium with 0.5 g/L ZnSO 4. Process conditions were optimized using statistical experimental design methodology. Four parameters were identified in the 2 8−4 fractional factorial design as having a significant effect on Zn accumulation: ZnSO 4 and Fe 2(SO 4) 3 concentrations, time of addition of the ZnSO 4 solution and concentration of soybean molasses. In the 3 2 experimental design, the influence of ZnSO 4 and Fe 2(SO 4) 3 concentrations were studied more closely. The highest Zn concentration (75,090 mg/kg dry weight) in the biomass was reached using the conditions: ZnSO 4, 10.0 g/L; Fe 2(SO 4) 3, 0.1 g/L in Erlenmeyer flasks. A batch liquid fermentation was carried out in a 2 L bioreactor for production of P. guilliermondii Wickerham LPB 063 containing organically bound Zn. The concentration of organically bound Zn after 144 h of fermentation was of 96,030 mg/kg, with a biomass production of 30 g/L. The maximum specific growth rate obtained ( μmax) was 0.0077/h, while the maximum productivity of biomass was at 0.1511 g/L/h. 相似文献
9.
Seed of flax ( Linum usitatissimum L.) grown on calcareous and neutral soils sometimes accumulates relatively high concentrations of Cd. The influence of a post-flowering application of NH 4NO 3 (115 mg N kg -1), CdSO 4 (1 mg Cd kg -1), FeEDDHA (2 mg Fe kg -1), NaH 2PO 4 (120 mg P kg -1) and ZnSO 4 (8 mg Zn kg -1) on seed accumulation of Cd, Fe, N, Mn, P and Zn by flax grown on a Calciaquoll was studied in two experiments under greenhouse conditions. Seed yields were increased by the N and Zn treatments, and the N×Zn interaction was positive. Zinc deficiency delayed flowering and boll formation by up to 20 days and reduced seed size. In the absence of added Cd, seed accumulated up to 0.33 mg Cd kg -1. This Cd accumulation was reduced by approximately 50 and 17% by added Zn and Fe, respectively, but was little affected by P fertilizer and post-flowering N stress. In the presence of added Cd, seed Cd exceeded 3.3 mg Cd kg -1, and the antagonistic effects of Fe and Zn on seed Cd were absent. Seed N, P, Fe and Zn concentrations were increased on average by 10, 45, 31 and 97% by the N, P, Fe and Zn fertilizer treatments, respectively. FeEDDHA reduced seed Mn concentration by approximately 58%. However, seed Mn concentration was much less than that found in vegetative tissue at flowering. Soil-applied Zn may reduce seed Cd concentration in flax under field conditions, and may increase marketability of flax for food use. 相似文献
10.
Summary Several Zn-deficient soils from the major rice growing areas in the USA were characterized with respect to extractable and labile Zn and other parameters including available P, pH, organic matter, and cation exchange capacity. A greenhouse experiment was conducted to determine whether the above factors influence the response of several rice cultivars to ZnSO 4 or ZnEDTA applied as a mixed preplant treatment or to the floodwater at panicle initiation.Response of the rice to Zn varied widely among soils with labile Zn (L value) being a poor indicator of Zn availability and soil pH, and DTPA or 2 N MgCl 2 extraction of Zn being the most reliable indices. Soil incorporation prior to flooding was more effective than floodwater application for the initial crop, but both methods of placement were comparable for a subsequent ratoon crop. In either situation, ZnSO 4 was superior to ZnEDTA. Recovery of Zn from ZnSO 4 was generally less than 5 percent where Zn response was obtained and up to 14 percent from nonresponsive soils. 相似文献
11.
Rice performance, in terms of plant height, productive tillering, yield and N-contents of grain and straw, harvest index (grain yield as a percentage of grain plus straw yields) and relative fertilizer N-use efficiency (kg grain yield/kg fertilizer-N) was enhanced by urea, ZnSO 4 and green manuring with Azolla caroliniana. Unlike urea fertilizer, calcium superphosphate increased the rate of azolla field colonization and promoted a thick, healthy dark-green mat of the fern. Response to ZnSO 4 was higher in the azolla-free sub-subplots. Application of ZnSO 4 corrected symptoms of Zn deficiency in rice but the addition of calcium superphosphate in the absence of Zn intensified the symptoms of Zn deficiency. 相似文献
12.
Diabetes mellitus is a serious worldwide metabolic disease, which is accompanied by hyperglycaemia and affects all organs and body system. Zinc (Zn) is a basic cofactor for many enzymes, which also plays an important role in stabilising the structure of insulin. Liver is the most important target organ after pancreas in diabetic complications. In this study, we aimed to investigate the protective role of Zn in liver damage in streptozotocin (STZ)‐induced diabetes mellitus. There are four experimental groups of female Swiss albino rats: group I: control; group II: control + ZnSO 4; group III: STZ‐induced diabetic animals and group IV: STZ‐diabetic + ZnSO 4. To induce diabetes, STZ was injected intraperitoneally (65 mg/kg). ZnSO 4 (100 mg/kg) was given daily to groups II and IV by gavage for 60 days. At the end of the experiment, rats were killed under anaesthesia and liver tissues were collected. In the diabetic group, hexose, hexosamine, fucose, sialic acid levels, arginase, adenosine deaminase, tissue factor activities and protein carbonyl levels increased, whereas catalase, superoxide dismutase, glutathione‐S‐transferase, glutathione peroxidase, glutathione reductase and Na +/K +‐ATPase activities decreased. The administration of Zn to the diabetic group reversed all the negative effects/activities. According to these results, we can suggest that Zn has a protective role against STZ‐induced diabetic liver damage. 相似文献
13.
In two separate studies, 60 beef heifers (379 kg BW) and 60 beef steers (348 kg BW) were randomly assigned to six treatments in 2×3 factorial arrangements. The treatments were with or without Synovex ® implants combined with either a control diet or diets supplemented with 200 ppm Zn from ZnSO 4 or zinc methionine (Zn-Met). Near the mid-point of the feeding periods, cattle were vaccinated with a modified live virus and subsequent titers and concentrations of immunoglobulin G (IgG) were measured. Liver and blood samples were obtained 1 week prior to the start of the experiments and at intervals during the experiments. In experiment 1, average daily gains of beef heifers were ( P<0.05) affected by the interaction of implant and source of dietary Zn. Compared to control and ZnSO 4 treatments, supplementation with Zn-Met increased ( P<0.05) the concentration of Zn in serum. Antibody titers and concentrations of IgG in serum were highest ( P<0.05) in heifers fed ZnSO 4 compared to heifers fed the control or Zn-Met supplemented diets. The Synovex-H ® implant reduced the concentrations of Zn and Cu in liver. In experiment 2, Synovex-S ® implants improved ( P<0.05) weight gains of steers supplemented with 200 ppm dietary Zn from ZnSO 4 compared to non-implanted steers. However, the implant had no effect when Zn-Met was the dietary Zn source. The implant increased ( P<0.05) concentrations of Zn in liver of steers supplemented with 200 ppm dietary Zn and reduced Zn in liver of steers fed the control diet. Implanted steers had higher ( P<0.05) Cu status and IgG concentrations in serum than non-implanted steers. Steers supplemented with either ZnSO 4 or Zn-Met had greater ( P<0.05) concentrations of Zn in liver and plasma than steers fed the control diet. These results indicate both the level and source of Zn supplementation in diets of feedlot cattle affect their response to growth implants. 相似文献
14.
This study aimed to investigate the effect of soil‐applied zinc (Zn) and manganese (Mn) rates on the development of aerial blight, caused by Rhizoctonia solani Kühn, in soybean. Plants (cv. ‘Conquista’) were grown in a typical Acrustox red‐yellow latosol amended with Zn rates (applied as ZnSO 4·7H 2O; 24% Zn) of 0, 1, 2, 4, 8 and 16 mg/dm 3 of soil and Mn rates (applied as MnSO 4·H 2O; 36% Mn) of 0, 1.5, 3 and 6 mg/dm 3 of soil and inoculated with R. solani. The relationship between Zn and Mn concentrations on leaf tissues and the rates of these micronutrients was linear. The incubation period was not affected by Zn and Mn rates. The relationship between application rates and the area under aerial blight progress curve was best described with a positive linear regression model for Zn and with a positive quadratic regression model for Mn. Results from this study showed that high foliar concentrations of Zn and Mn do not increase soybean resistance to aerial blight. 相似文献
15.
The critical concentration of Zn in wheat tissues for the prediction of Zn response and diagnosis of Zn deficiency was examined in a glasshouse experiment with wheat ( Triticum aestivum, line QT 4118) grown to anthesis in two Vertisols at Zn application rates of 0, 1.25, 2.5, 5, 10, 15 and 30 kg ha -1 equivalent as ZnSO 4 7H 2O. The wheat tissues examined were the youngest mature leaf blade (YMB), the leaf immediately below the youngest mature leaf blade (YMB-1), the older leaves, the ear, the stem and the whole tops. The minimum Zn concentration required in a tissue at 0.90 relative yield, referred to as the critical Zn concentration, was determined using the Cate-Nelson graphical and statistical models, the Mitscherlich equation and a two-intersecting straight lines model. The Zn status of wheat was best defined by the Zn concentration in the YMB. Although the critical Zn concentration of the YMB did not vary much with the method of estimation, the Cate-Nelson statistical procedure explained a higher percentage of the variation in Zn concentration in the YMB and relative yield than the Mitscherlich and the two intersecting straight lines models. The critical concentration of Zn in the YMB was 16.0 mg kg -1 dry matter. It is concluded that determination of Zn concentration in the YMB is the best procedure for evaluating the Zn status of wheat plants. 相似文献
16.
In isolated barley chloroplasts, the presence of 2 millimolar ZnSO 4 inhibits the electron transport activity of photosystem II, as measured by photoreduction of dichlorophenolindophenol, O 2 evolution, and chlorophyll a fluorescence. The inhibition of photosystem II activity can be restored by the addition of the electron donor hydroxylamine or diphenylcarbazide, but not by benzidine and MnCl 2. These observations suggest that Zn inhibits electron flow at the oxidizing side of photosystem II at a site prior to the electron donating site(s) of hydroxylamine and diphenylcarbazide. No inhibition of photosystem I-dependent electron transport by 3 millimolar ZnSO 4 is observed. However, with concentrations of ZnSO 4 above 5 millimolar, photosystem I activity is partially inactivated. Washing Zn 2+-treated chloroplasts partially restores the O 2-evolving activity. 相似文献
17.
A study was conducted in a screen house in pots on a sandy loam soil deficient in Zn. Salinity was induced by adding 44, 88 and 132 me/l of chloride and sulphate salts in the saturation extract. To these treatments, 0, 5 and 10 ppm Zn were added as ZnSO 4·7H 2O or Zn-EDTA. The results indicated that the yield of soybean shoot was lowest at the highest salinity level and highest at the lowest level. Shoot yield improved markedly with Zn application. Both sources of Zn were equally effective in augmenting crop yields. Yields were low in Cl-salinity when compared with equivalent levels of SO 4-salinity. Application of ZnSO 4·7H 2O produced higher yields in SO 4-dominant salinity. Zinc content increased and Zn uptake decreased with increase in Cl-salinity regardless of Zn sources. In SO 4-salinity, ZnSO 4·7H 2O did not influence the Zn content, but uptake was suppressed with increase in SO 4-salinity. Increasing rates of SO 4-salinity enhanced Zn content in the presence of Zn-EDTA. 相似文献
18.
Brown spot, caused by the fungus Bipolaris oryzae, is one of the most destructive diseases of rice. This study investigated the effect of zinc rates on the development of brown spot in rice. Rice plants (cv. ‘Metica‐1′) were grown in hydroponic culture amended with Zn rates (applied as ZnSO 4.7H 2O) of 0, 0.5, 1, 2 and 4 μm and inoculated with B. oryzae. The foliar concentration of Zn was determined. Leaf samples were assessed for disease severity, and then, area under brown spot progress curve (AUBSPC) was calculated. The relationship between Zn concentrations on leaf tissues and the rates of this micronutrient was best described by a positive linear regression model, while the relationship between the Zn rates and the AUBSPC was best described with a positive quadratic regression model. The correlation between Zn concentrations on leaf tissues and AUBSPC was positive and significant ( r = 0.68, P < 0.05). The results from this study showed that high foliar concentration of Zn was associated with increasing rice susceptibility to brown spot. 相似文献
19.
BackgroundZinc (Zn) biofortification through foliar Zn application is an attractive strategy to reduce human Zn deficiency. However, little is known about the biofortification efficiency and bioavailability of rice grain from different forms of foliar Zn fertilizers. Methodology/Principal FindingsFour different Zn forms were applied as a foliar treatment among three rice cultivars under field trial. Zinc bioavailability was assessed by in vitro digestion/Caco-2 cell model. Foliar Zn fertilization was an effective agronomic practice to promote grain Zn concentration and Zn bioavailability among three rice cultivars, especially, in case of Zn-amino acid and ZnSO 4. On average, Zn-amino acid and ZnSO 4 increased Zn concentration in polished rice up to 24.04% and 22.47%, respectively. On average, Zn-amino acid and ZnSO 4 increased Zn bioavailability in polished rice up to 68.37% and 64.43%, respectively. The effectiveness of foliar applied Zn-amino acid and ZnSO 4 were higher than Zn-EDTA and Zn-Citrate on improvement of Zn concentration, and reduction of phytic acid, as a results higher accumulation of bioavailable Zn in polished rice. Moreover, foliar Zn application could maintain grain yield, the protein and minerals (Fe and Ca) quality of the polished rice. ConclusionsFoliar application of Zn in rice offers a practical and useful approach to improve bioavailable Zn in polished rice. According to current study, Zn-amino acid and ZnSO 4 are recommended as excellent foliar Zn forms to ongoing agronomic biofortification. 相似文献
20.
It has been shown previously (Treeby et al., 1989) that phytosiderophores, released by roots of iron deficient grasses (Gramineae), mobilize from calcareous soils not only iron (Fe) but also zinc (Zn), manganese (Mn) and copper (Cu). Mobilization of Fe may therefore be impaired by other micronutrient cations. This has been studied in both, model experiments with Fe hydroxide and with a calcareous soil (15% CaCO 3, pH 8.6) amended with micronutrients as sulfate salts.Mobilization of Fe from Fe hydroxide by phytosiderophores (epi-3-hydroxymugineic acid) was not affected by the addition of CaCl 2, MgSO 4 and MnSO 4, slightly inhibited by ZnSO 4 and strongly inhibited by CuSO 4. In a calcareous soil amended with increasing levels of ZnSO 4, MnSO 4 and CuSO 4, mobilization of Fe by phytosiderophores remained uneffected by Zn and Mn amendments but was progressively impaired by increasing levels of Cu amendment, correlated with corresponding enhancement of Cu mobilization.High concentrations of ZnSO 4 and MnSO 4 and relatively high concentrations of CuSO 4 were required for inhibition of Fe mobilization by phytosiderophores. It is therefore concluded that in most calcareous soils phytosiderophores efficiently mobilize Fe, and that phytosiderophores play an important role in Fe acquisition by grasses grown on calcareous soils. 相似文献
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