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1.
Abstract

An irrigated field trial was conducted to test the effects of white clover in three turfgrass species (perennial ryegrass, Kentucky bluegrass, and creeping bentgrass) on color, clipping yield, and botanical composition and to estimate nitrogen (N)2 fixation and N transfer from white clover to associated turfgrass species under different N‐fertilization conditions in 1999–2002.

Nitrogen fertilizers significantly increased color ratings in all observations. Grass–white clover mixtures had better color ratings than pure grass at all sampling dates and seasonal averages in unfertilized conditions. Fertilized pure grass plots yielded significantly more than control plots in all turfgrass species. Nitrogen fertilization did not affect clipping yield greatly in turfgrass–white clover mixtures. Nitrogen application significantly decreased white clover percentage in the harvested clippings in second and third year.

Nitrogen fertilization increased tissue N concentration positively in all turfgrass species grown alone. In contrast, N fertilization did not greatly affect tissue N concentration of either turfgrass species or white clover in the mixtures. Nitrogen fixation of white clover was estimated as 24.6, 30.7, and 33.8 g m?2 year?1 in perennial ryegrass, Kentucky bluegrass, and creeping bentgrass, respectively. The total estimated N2 fixation gradually decreased with increasing N fertilization. Nitrogen transfer from white clover to the associated turfgrass varied from 4.2 to 13.7% of the total N that the white clover fixed annually.  相似文献   

2.
为解决暖季型草坪草越冬期枯黄的问题,以沟叶结缕草为材料,利用L9(34)正交试验设计方法设计了植物生长调节剂、速效肥与有机肥3因子3水平正交混施试验.与清水对照相比,处理组沟叶结缕草叶面积指数、叶绿素含量、叶片游离脯氨酸和可溶性糖含量均显著提高,且根系活性、叶片抗氧化酶系(SOD、POD、CAT)活性显著增加,叶片丙二醛含量则显著降低.处理组整体上提高了草坪草越冬期的生长及抗冷性能,显著改善了草坪草的冬季景观效果.因子间极差分析表明,主效因子随草坪草生长和抗性指标的不同而存在差异,表明混施时各因子在保持草坪草冬季良好生长、提高抗性生理功能上所起的作用具有互补性.综合各指标正交分析结果,提出了混施的最优配方,即每升混合液肥中含多效唑、三十烷醇、硫酸钾镁肥、尿素和壳聚糖300mg、2mg、1 500mg、1 000mg和1 000mg,按200mL·m-2叶面喷施,花生饼按90 g·m-2撒施.  相似文献   

3.
Turfgrass cover is an inevitable component in the urban landscapes of the United Arab Emirates. Tolerance to abiotic stress like salt, drought, and high temperature is a potential factor to be considered in the selection of turfgrass for the landscapes in the arid regions. Three Seashore paspalum genotypes, four Bermudagrass cultivars along with tall fescue as a control were screened for enzymatic changes under four different saline irrigation levels of 5,000, 10,000, 15,000, and 20,000 mg L?1 of salinity. Irrigation with potable water served as the control. Turfgrasses were maintained in a field experiment under factorial randomized block design for a period of two years under sustained saline conditions by working out the leaching fraction to maintain the precise level of salinity in each treatment throughout the experimental period. The activities of antioxidant enzymes such as superoxide dismutase (SOD), ascorbate peroxidase (APX), peroxidase (POD), polyphenol oxidase (PPO), and catalase (CAT) were assayed in each of the saline water treated turfgrass types. The SOD activity was found to be high in Yukon (bermudagrass) and Sea Dwarf paspalum. In the paspalum group, Salam and Sea Dwarf showed the highest SOD activity under saline condition. In Bermuda types, Yukon and SR 9554 showed the highest SOD activity compared to other bermuda types. Compared to other cultivars, Sea Isle 2000 (Paspalum type), SR 9554, and Yukon (Bermuda types) exhibited more APX activity without any significant differences among themselves. There was an elevated activity of POD initially, followed by gradual reduction upon increasing the salinity level. Salam cultivar maintained stable POD activity even at the elevated salinity levels. The paspalum types showed relatively high level of PPO activity compared to other types under salinity. Yukon cultivar showed a significantly higher activity of PPO when the salinity level was raised from 15,000 to 20,000 mg L?1. A significant increase with respect to CAT activity was exhibited in Sea Dwarf under elevated level of salinity. Saline water irrigation brought about a significant effect on the antioxidant enzyme systems to impart oxidative stress tolerance in turfgrass species.  相似文献   

4.
ABSTRACT

Limited information comparing foliar versus granular fertilization of turfgrasses is available. The objective of this research was to evaluate liquid and/or granular N fertilization on turfgrass quality, clipping yield, and root biomass of ‘L-93’ creeping bentgrass. Treatments consisted of two annual nitrogen (N) inputs, 127 and 190 kg ha?1, using 100% granular urea fertilizer, 50% granular urea + 50% liquid urea fertilizer, or 100% liquid urea fertilizer. These results suggest a rate of at least 190 kg N ha?1 yr?1 is needed to maintain acceptable bentgrass quality in the transition zone of the U.S. Combining both liquid and granular methods appear superior compared to relying on one method exclusively.  相似文献   

5.
Silicon (Si), applied as calcium silicate (Ca-silicate), was evaluated for effects on yield; yield-contributing parameters in sugarcane, such as chlorophyll content, gas exchange characteristics, moisture content, and leaf nutrient concentrations; and soil fertility in the greenhouse in two different soil types. Seven levels of Si (0 20, 40, 60, 80, 120, and 150 g pot–1) were tested by applying them with traditional fertilizers. Gas exchange characteristics such as photosynthesis, transpiration, and stomatal conductance were significantly greater with the plants fertilized with silicate over unamended control for both soils. Silicate fertilization increased chlorophyll and moisture contents in the top visible dewlap (TVD) leaf tissues, but results were not significantly better in both soils when compared with unamended control. In our 12-month study, we found that the Si content reached up to 2.64% and 1.86% per dry mass in TVD leaf tissues when amended with Ca-silicate fertilizer in soils 1 and 2, respectively. Results showed that as compared to unamended control, Si-amended treatments significantly increased maximum dry matter and cane yield by 77% and 66% in soil 1 and 41% and 15% in soil 2, respectively. With increasing silicate application, iron, copper, zinc, and manganese contents significantly decreased in leaf tissues and soil contents in both soils. Soil pH, Si contents, available sulfur, exchangeable Ca and magnesium, and cation exchange capacity were increased significantly more or less, whereas aluminum contents of soil decreased dramatically in both soils when amended with Ca-silicate. Our results indicate that different soil fertility status and rates of Si application are important factors influencing the yield, growth parameters, chlorophyll, and nutrient contents of sugarcane leaf as well as soil properties.  相似文献   

6.
This study was designed to examine whether external calcium (Ca2+) would improve the tolerance of Trifolium repens L to polyethylene glycol (PEG)-induced water deficit, and to determine the physiological mechanisms of Ca2+ effect on plant tolerance to water deficit. T. repens seedlings were subjected to PEG-induced water deficit alone or combined with 5 mM calcium chloride (CaCl2) for 72 h. During PEG-induced water deficit period, leaf relative water content (RWC) decreased gradually, and chlorophyll content increased after 24 and 48 h of water deficit but decreased below the control level after 72 h. The Ca2+-treated plants had higher RWC and chlorophyll content than untreated plants. Smaller amounts of thiobarbituric acid reactive substances (TBARS) and hydrogen peroxide (H2O2) accumulated in Ca2+-treated plants than in untreated plants during the period of water deficit. The activity of superoxide dismutase (SOD) increased gradually during the experimental period, and external Ca2+ treatment further promoted SOD activity under water deficit. The activity of the catalase (CAT) was not influenced after 24 and 48 h of water deficit and insignificantly increased after 72 h, whereas the activity of ascorbate peroxidase (APOX) increased linearly and glutathione reductase (GR) activity slightly increased over the course of treatment. Seedlings treated with Ca2+ had higher CAT, GR, and APOX activities than untreated plants under water deficit. These results suggested that exogenous Ca2+ application enhanced T. repens tolerance to PEG-induced water deficit, and this enhancement was related to alleviation of lipid peroxidation and maintenance of antioxidant activities.  相似文献   

7.
We investigated the effects of silicon (Si) and the levels and sources of salinity on the growth and some physiological properties of wheat (Triticum aestivum cv. Chamran) in a sandy loam soil under greenhouse conditions. Treatments comprised four Si levels (8, 50, 100 and 150 mg kg?1 soil), four salinity levels (0.46, 4, 8 and 12 dS m?1) and two salinity sources (sodium chloride (NaCl) and four-salt combination). Salts combination included NaCl, sodium sulfate (Na2SO4), calcium chloride (CaCl2) and magnesium sulfate (MgSO4) at a molar ratio of 4:2:2:1. The experiment was arranged as a completely randomized design in a factorial manner, with three replications. Increasing salinity level resulted in a significant decrease in shoot dry weight, chlorophyll content and catalase (CAT) activity, and it caused a marked increase in proline and glycine betaine (GB) concentrations and superoxide dismutase (SOD) enzyme activity. The stimulating effect on GB accumulation and SOD activity was more intense in NaCl-treated plants. However, the source of salinity had no significant effect on shoot dry weight, chlorophyll and proline concentrations, and CAT activity. Si application enhanced all the above-mentioned parameters, except for proline. The suppressing effect of salinity on shoot dry weight, chlorophyll concentration and CAT activity was alleviated by Si supplementation. The stimulating effects of Si fertilization on shoot dry weight and chlorophyll concentration became more pronounced at higher salinity levels. It could be concluded that a decrease in soil osmotic potential, nutrient imbalance and increasing reactive oxygen species (ROS) in salt-treated plants caused growth suppression, while Si supply decreased the deleterious effects of excess salt on wheat growth. Consequently, it appears that when wheat plants are to be grown in salt-affected soils, it is highly recommended to supply them with adequate available silicon (Si).  相似文献   

8.
Four different tree species, Zizyphus mauritiana, Syzygium cumini, Azadirachta indica and Mangifera indica were analyzed for stomatal conductances, sulphate, protein, superoxide dismutase and peroxidase activities for one complete year in an ambient environment with SO2 concentrations ranging between 90 to 10 ug m?3. The low conductances, declined protein content and enhanced sulphate content, superoxide dismutase (SOD) and peroxidase (POD) activities were the general responses exhibited by these species when compared with to the reference site. The pattern of the results indicate that plants under SO2 stress develop an ability to detoxify the phytotoxicity by undergoing certain biochemical changes. Plants which posses high intitial POD activities coupled with greatly enhanced SOD activity (Z. mauritiana) or plants which can enhance both POD and SOD activities (S. cumini) were more tolerant/least affected than that of A. indica and M. indica.  相似文献   

9.
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10.
A 3-year field study was conducted to determine the influence of nitrogen (N) application timing on the growth and quality of a turfgrass mixture consisting of perennial ryegrass (Lolium perenne L.), Kentucky bluegrass (Poa pratensis L.), creeping red fescue (Festuca rubra var. rubra L.), and chewings fescue (Festuca rubra var. commutata Gaud.) under irrigated conditions. Nitrogen was applied annually at the rate of 30 g m?2 year?1, with six application regimes: control (no N), single spring (30 g m?2), single fall (30 g m?2), spring + fall (15 + 15 g m?2), spring + summer + fall (10 + 10 + 10 g m?2), and monthly from April through September (5 g m?2).

Color, turf quality, clipping weights, and shoot density were correlated with fertilizer rates and application timing in this study. Fertilization monthly or every 2 months resulted in more uniform color and turf quality and less clipping weights than with comparable heavy spring and fall fertilizations. Heavy N applications in the fall did not cause winter injury and produced significantly darker color and more uniform appearance in early spring than other N applications. All N-fertilization regimes increased shoot density, but spring fertilization stimulated density the most. Nitrogen applied monthly or every 2 months was enough to enhance the color, turf quality, and shoot density of the turf during the growing season but did not greatly affect the growth rate.  相似文献   

11.
To investigate effects of manganese (Mn) deficiency (0 μM L–1) on concentrations of chlorophyll, superoxide dismutase (SOD) activity, biomass, and accumulations of active constituents in Glycyrrhiza uralensis Fisch., seedlings of 1-year-old G. uralensis were grown in a nutrient solution for 60 days. In this experiment, three concentrations of Mn were set up: 0 (–Mn), 7 μM L–1, and 14 μM L–1 Mn. The results showed that –Mn decreased the concentration of chlorophyll a with no significant differences in concentrations of chlorophyll b, total chlorophyll a + b, carotenoids, and chlorophyll a/b ratio. On days 45 and 60, SOD activity significantly decreased. However, dry weight of roots under –Mn showed no significant difference during the whole experiment. The accumulations of glycyrrhizic acid and liquiritin were significantly inhibited by Mn deficiency at different times. Thus results indicated that Mn deficiency could affect growth and contents of its secondary metabolites of G. uralensis.  相似文献   

12.
Abstract

A salt-sensitive cucumber cultivar “Jinchun No. 2” (Cucumis sativus L.) was used to investigate the role of proline in alleviating salt stress in cucumber. Proline was applied twice (day 0 and day 4 after salt treatment) as a foliar spray, with a volume of 25?mL per plant at each time. Plant dry weight, leaf relative water content, proline, malondialdehyde (MDA), Na+, K+ and Cl? contents, as well as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) activities in the plants were determined at day 8 after salt treatment. The results showed that 100?mmol?L–1 NaCl stress significantly decreased plant dry weight, leaf relative water and K+ contents, and increased leaf MDA, Na+ and Cl? contents and SOD, POD, CAT and APX activities. However, leaf proline accumulation was not affected by salinity. The exogenous application of proline significantly alleviated the growth inhibition of plants induced by NaCl, and was accompanied by higher leaf relative water content and POD activity, higher proline and Cl? contents, and lower MDA content and SOD activity. However, there was no significant difference in Na+ and K+ contents or in CAT and APX activities between proline-treated and untreated plants under salt stress. Taken together, these results suggested that the foliar application of proline was an effective way to improve the salt tolerance of cucumber. The enhanced salt tolerance could be partially attributed to the improved water status and peroxidase enzyme activity in the leaf.  相似文献   

13.
水氮耦合对黍稷幼苗形态和生理指标的影响   总被引：1，自引：0，他引：1  
盆栽试验条件下,研究水氮耦合对黍稷幼苗形态和生理指标的影响。结果表明,在供水量相同条件下,黍稷幼苗株高、叶面积、根系总表面积、总体积与总根长均随施氮量的增加而增加,供水量相同时根冠比随施氮量增加而降低;施氮量相同条件下随灌水量的增加黍稷幼苗各指标呈相似变化趋势,各处理与对照差异均达到了显著水平。不同的水氮处理组合,黍稷叶片叶绿素含量差异显著,以高水高氮的W3N3处理[土壤田间持水量70%~80%,尿素用量4.6 g.kg 1(土)]为最大值,低水低氮的W1N1处理[土壤田间持水量30%~40%,尿素用量为0 g.kg 1(土)]为最小值;灌水量相同,叶绿素含量随施氮量增加而增加;施氮量相同,叶绿素含量也随灌水量增加而增加,水分和氮素对叶片叶绿素含量的影响表现为明显的协同效应;黍稷幼苗叶片电解质外渗率的变化趋势则相反。黍稷根系超氧化物歧化酶活性以低水中氮的W1N2处理[土壤田间持水量30%~40%,尿素用量2.3 g.kg 1(土)]为最高,达213.71 U.g 1(FW);W3N3最低,为72.93 U.g 1(FW)。水分相同条件下黍稷幼苗根系过氧化物酶活性、丙二醛含量、可溶性糖含量均随施氮量的增加而降低,施氮量相同时则随灌水量的增加而降低。根系活力则相反,且各处理间差异均达到显著水平。在干旱胁迫条件下,适当的增施氮肥可以提高苗期黍稷的叶绿素含量和根系活力,增加根系总表面积、总体积与总根长,降低根系丙二醛含量,在一定程度上缓解干旱胁迫的影响。  相似文献   

14.
Abstract

Given the growing adoption and use of recycled irrigation across the turfgrass industry, there is importance in understanding the effects of irrigation chemistry on N uptake efficiency as it relates to various soluble N sources. The objective of this study was to determine interactive effects of three soluble N sources (ammonium sulfate, potassium nitrate, and urea) and three irrigation water sources (reverse osmosis (R.O.), sodic potable, and 2.5 dS m?1 saline (SA)) on turfgrass performance and 15N nitrogen uptake efficiency following foliar N fertilization. Results demonstrated that although all water and N source treatments produced above-acceptable levels of quality in Champion bermudagrass, both N and water source significantly impacted nitrogen uptake efficiency. Following an eight-hour uptake period, approximately 40 to 70% of foliar-applied N (from a 0.5?g N m?2 application) was recovered across all N sources. The highest uptake efficiency was noted with ammonium sulfate and urea treatments, with noticeably lower recoveries of N detected with potassium nitrate fertilization. Ammonium sulfate produced similar or improved turf quality to other N sources under R.O. and sodic potable irrigation, but reduced turf quality and green cover under saline irrigation. When water sources containing moderately high salinity levels (2.5 dS m?1) are used, potassium nitrate (KNO3) may provide the greatest turfgrass quality, however, its uptake efficiency may be lower than other N sources. The results suggest that soluble N source and tank mix and/or irrigation water chemistry may be important considerations for maximizing foliar uptake efficiency and minimizing potential for environmental loss.  相似文献   

15.
Application of plant growth regulator (PGR) may alleviate some negative effects of environmental stresses such as salinity. A controlled environment experiment was conducted to study barley (Hordeum vulgare L. cv. Reyhane) growth, yield, antioxidant enzymes and ions accumulation affected by PGRs under salinity stress conditions at Shiraz University during 2012. The treatments were PGRs at four levels—water (as control), cycocel (CCC, 19 mM), salicylic acid (SA, 1 mM), and jasmonic acid (JA, 0.5 mM)—and four salinity levels—no stress (0.67 dS m?1, as control), 5, 10, and 15 dS m?1, which were arranged in a factorial experiment based on completely randomized design with four replicates. The results showed that salinity stress significantly decreased plant height, peduncle length, leaf area, ear length, grain number, dry weight, grain yield, harvest index, potassium (K+) accumulation, and potassium/sodium (K+/Na+) concentration ratio, which were closely associated with stress severity. However, PGRs compensated some of these negative effects, so that SA foliar application had the most ameliorative effect. Salt stress also increased Na+ accumulation as well as the activity of peroxidase, catalase, and superoxide dismutase (SOD). Since ion discrimination and enhanced antioxidant enzymes are associated with salt tolerance, in this experiment PGRs application might have enhanced K+ accumulation and antioxidant enzyme activity. The activity of SOD and K+/Na+ ratio were found to be useful in salt tolerance manipulation in barley plants.  相似文献   

16.
Cultivation of green manure plants during the fallow season in rice paddy soil has been strongly recommended to improve soil properties. However, green manuring may impact greenhouse gas emission, methane (hereafter, CH4) in particular, under the flooded rice cultivation and thus, application of chemical amendments being electron acceptors can be an effective mitigation strategy to reduce CH4 emissions in irrigated rice (Oryza sativa L.) field amended with green manure. To investigate the effect of iron (Fe) slag silicate fertilizer (hereafter, silicate fertilizer), which was effective in reducing CH4 emission and increasing rice productivity, in green manure-amended paddy soil, the aboveground biomass of Chinese milk vetch (hereafter, vetch) was added at rates of 0, 10, 20, and 40 Mg (fresh weight) ha−1 before the application of silicate fertilizer, which was added at rates of 0 and 2.3 Mg ha−1. Silicate fertilization reduced the seasonal CH4 flux by ca. 14.5% and increased rice yield by ca. 15.7% in the control (no vetch application) treatment. However, CH4 production was increased by silicate fertilization in vetch-treated soil particularly at the initial rice growing stage, which was probably due to the enhanced decomposition of added organic matters by the silicate liming effect. In conclusion, silicate fertilization is not effective in reducing CH4 production in green manure-amended rice paddy soils and its use should be properly controlled.  相似文献   

17.
Salinity stress is one of the important agricultural problems in the world. A factorial experiment based on completely randomized design with four replications was conducted to evaluate the effects of phytohormones (gibberellic acid and abscisic acid) on the activity of antioxidant enzymes (peroxidase, superoxide dismutase and catalase), rubisco activity and content, and proline in three wheat cultivars (Gascogen, Zagros, and Kuhdasht) under control and salinity stress (3.5 and 7 dS m?1). The results showed that salinity stress (3.5 and 7 dS m?1) decreased the activity of catalase, rubisco, carboxylase, but increased peroxidase, superoxide dismutase activity and proline content. Gibberellic acid caused 58.03% increased in rubisco carboxylase activity in Zagros at 7 dS m?1 in comparison with abscisic acid under salinity stress compared with the control plants in Kuhdasht. Activity of superoxide dismutase in Kuhdasht cultivar at 7 dS m?1 salinity level showed 76.43% increased in Gascogen under salinity stress compared with the control plants with gibberellic acid application. The highest proline content as an osmolyte was found in Zagros at 7 dS m?1 salinity level with abscisic acid (194 μmol g?1 DM) application. Peroxidase activity increased 83.31% and catalase activity decreased 61.27% compared with the control plants in Zagros. Gibberellic acid application significantly prevented reduction in rubisco content under salinity stress. In conclusion, increased in peroxidase and superoxide dismutase activity and proline content decreased the adverse effects of salinity stress on studied cultivars. Also, the foliage spray of gibberellic acid enhanced and improved the growth condition. In this experiment, Zagros cultivar showed more tolerance to salinity stress than the other two cultivars.  相似文献   

18.
The effect of copper (Cu) excess (1.5, 4.7, 31, 78, 156 μM) and exogenously supplied succinate on plant growth, chlorophyll content, chlorophyll fluorescence, and isoenzym profiles of some antioxidant enzymes in maize plants was studied. Excessive Cu supply led to a reduction in the relative growth rate (RGR), tolerance index (TI), chlorophyll a and chlorophyll b contents, and the quantum yield of PSII electron transport in the light‐adapted state (ΦPSII). Copper treatment induced several changes in the anionic and cationic peroxidases (PODs), as well as superoxide dismutase (SOD) isoenzyme profiles. After 8 d of 78 μM–Cu treatment, two new anionic and two new cationic peroxidase isoenzymes in the roots were registered. Copper applied at concentrations above 31 μM resulted in higher levels of manganese superoxide dismutase (Mn‐SOD) in the roots and Cu,Zn‐superoxide dismutase (Cu,Zn‐SOD) in the leaves. However, the addition of Na‐succinate (200 μM) to the root medium prior to Cu treatment increased the capacity of the plants to partially overcome Cu toxicity.  相似文献   

19.
Understanding phosphorus (P) release under different climatic or moisture regimes will facilitate effective management of plant nutrition. The objective of this study is to evaluate the effect of two soil moisture regimes on P release from Ogun rock phosphate (ORP) and Sokoto rock phosphate (SRP) in two soil types. Soil was poured into soil columns to form lower and top layers. Top layer was mixed with 400 kg ha?1 P from ORP, SRP, single super phosphate (SSP) and leached with 35.4 cm3 water representing low moisture regime (LMR; 400 mm rainfall) and 106.1 cm3 water for high moisture regime (HMR; 1200 mm rainfall). P concentrations of leachates, available P in soil and soil pH were determined. Cumulative P leached was higher under HMR than LMR in both soils. There was more leaching with SSP (0.41–0.97 mg P) than both phosphate rocks (0.008–0.19 mg P) indicating leaching potential of SSP. Cumulative P leached from SSP treated Olokemeji soils was twice that of acidic Sapoba under LMR while they were similar (Olokemeji, 0.97 mg P; Sapoba, 0.94 mg P) under HMR suggesting that LMR enhances fixation of P in acidic soils. Irrigation of P fertilized soils may reduce P sorption in acidic soils.  相似文献   

20.
Rising 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.  相似文献   

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