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1.
研究了在缺氮条件下,CO2倍增对大豆(GtycinemaxL.)Bragg及其等基因突变体超结瘤大豆nts382和不结瘤大豆Nod49生长和固氮的影响。结果表明在缺氮条件下CO2倍增明显提高大生物量和根系结涵量,但对固氮酶活性的影响则随幼苗的生长而异。播种后25天取样结果显示CO2倍增条件下,Bragg和nts382的固氮比活性和单株固氮活性都显著提高,而其后3天取样的结果没有表现出增加趋势,固氮比活性在nts382反而明显降低。两种CO2浓度条件下,nts382单株固氮活性高于Bragg,但固氮比活性低于后者。两次测定结果的差异说明植物对CO2倍增的反应具有很强的时效性;同时表明,CO2倍增对植物生长和固氮的促进作用不能长期维持。这可能与生物固氮过程本身的复杂性有关。根据本研究结果推测,在未来全球环境变化、CO2倍增条件下,共生固氮植物可能在生态系统氮素平衡中起到更为重要的作用;并有可能通过育种技术改良固氮农作物,提高农作物产量。  相似文献   

2.
在短期无氮营养液栽培条件下研究了缺硼和正常供硼处理对大豆超结瘤突变体(nts382)及其亲本Bragg根瘤结构和根瘤固氮酶活性的影响。结果表明:1.在缺硼条件下,无论是超结瘤突变体nts382,还是亲本Bragg,其根瘤固氮酶活性都显著下降;2.无论是缺硼还是正常供硼处理,超结瘤突变体nts382单位鲜重根瘤活性都明显低于亲本,但由于nts382每株根瘤数和鲜重显著高于其亲本,使每株固氮酶活性明显高于亲本,植株中氮素积累总量也相应的高于亲本;3.缺硼条件下,根瘤细胞结构发生明显改变,细胞壁凸凹不平,细胞间隙加大,含菌细胞内类菌体含量减少。这可能是硼影响根榴细胞正常固氮功能的主要原因。  相似文献   

3.
在短期无氮营养液栽培条件下研究了缺硼和正常供硼处理对大豆超结瘤突变体(nts382)及其亲本Bragg根瘤结构和根瘤固氮酶活性的影响。结果表明:1.在缺硼条件下,无论是超结瘤突变体nts382,还是亲本Bragg,其根瘤固氮酶活性都显著下降;2.无论是缺硼还是正常供硼处理,超结瘤突变体nts382单位鲜重根瘤活性都明显低于亲本,但由于nts382每株根瘤数和鲜重显著高于其亲本,使每株固氮酶活性明显高于亲本,植株中氮素积累总量也相应的高于亲本;3.缺硼条件下,根瘤细胞结构发生明显改变,细胞壁凸凹不平,细胞间隙加大,含菌细胞内类菌体含量减少。这可能是硼影响根榴细胞正常固氮功能的主要原因。  相似文献   

4.
矮香糯水稻(Oryza sativa L, )插身后生长在大气(350ppm CO2)和CO2倍增(700 ppm CO2)的开顶式培养室中,结果显示,在CO2倍增的条件下,矮香糯生长旺盛,根系发达,根系干重增加23%,株高增加12%,每穗结实率增加29%,每株籽粒干重增加41%。本文对目前有关这方面的研究现状进行了讨论。  相似文献   

5.
在短期无氮营养液栽培(28天)条件下,研究缺硼和正常供硼处理对Bragg大豆品种及不结瘤突变体nod49和超结瘤突变体nts382生长、矿质元素吸收与分布及固氮量的影响。试验结果表明:1.在正常供硼的条件下,不结瘤突变体nod的植株生长量,株高、主根生长均高于超结瘤突变体及其亲本。缺硼处理时三种基因型大豆的生长均受到明显的抑制作用。无论是正常供硼还是缺硼处理,超结瘤突变体nts382根系的生长量均明显小于其它基因型。2.正常供硼处理时三种基因型大豆地上部、根及nts382的根瘤中硼的浓度和积累量均高于缺硼处理。缺硼处理,超结瘤突变体及其亲本地上部和根中大部分矿质元素浓度高于正常供硼处理,但积累总量低于正常供硼处理或变化不大。施硼处理的nts382和Bragg,根和根瘤中钙的浓度和积累量明显降低,而地上部变化不大,同时在nts382根瘤中,锌、锰、铁、铜浓度和含量也下降,而钼含量增加。3.施硼处理和Bragg和nts382地上部、根及根瘤中氮的浓度和含量均显著高于缺硼处理,其中超结瘤突变体中氮浓度和总量最高。在缺硼条件下,Bragg和超结瘤突变体能够结瘤,但是Bragg大豆根瘤的固氮作用完全受到抑制,而nts382根瘤还能保持较强的固氮能力。  相似文献   

6.
在短期无氮营养液栽培(28天)条件下,研究缺硼和正常供硼处理对Bragg大豆品种及不结瘤突变体nod49和超结瘤突变体nts382生长、矿质元素吸收与分布及固氮量的影响。试验结果表明:1.在正常供硼的条件下,不结瘤突变体nod的植株生长量,株高、主根生长均高于超结瘤突变体及其亲本。缺硼处理时三种基因型大豆的生长均受到明显的抑制作用。无论是正常供硼还是缺硼处理,超结瘤突变体nts382根系的生长量均明显小于其它基因型。2.正常供硼处理时三种基因型大豆地上部、根及nts382的根瘤中硼的浓度和积累量均高于缺硼处理。缺硼处理,超结瘤突变体及其亲本地上部和根中大部分矿质元素浓度高于正常供硼处理,但积累总量低于正常供硼处理或变化不大。施硼处理的nts382和Bragg,根和根瘤中钙的浓度和积累量明显降低,而地上部变化不大,同时在nts382根瘤中,锌、锰、铁、铜浓度和含量也下降,而钼含量增加。3.施硼处理和Bragg和nts382地上部、根及根瘤中氮的浓度和含量均显著高于缺硼处理,其中超结瘤突变体中氮浓度和总量最高。在缺硼条件下,Bragg和超结瘤突变体能够结瘤,但是Bragg大豆根瘤的固氮作用完全受到抑制,而nts382根瘤还能保持较强的固氮能力。  相似文献   

7.
空间电场对植物吸收CO2和生长速度的影响   总被引:1,自引:0,他引:1  
为研究空间电场对植物吸收CO2和生长速度的影响,首先采用同位素示踪法,分析了不同空间电场调控营养液栽培的番茄秧吸收CO2气体和HCO-3阴离子的能力,证实了 14C—HCO-3是一种受控于空间电场变化的阴离子,且空间电场强度的变化方向调控着 14C—HCO-3阴离子流的流动方向。在此基础上以蕹菜(空心菜)为试验材料,采取空间电场与增施CO2浓度的参数组合,做对比生长试验,通过红外线CO2分析法揭示了空间电场的极性对植物吸收CO2的速度有显著影响,且正向空间电场能显著促进植物对CO2的吸收,并得到正向空间电场与足量的CO2浓度相配合能大幅度提高温室蔬菜生长速度,使作物产量倍增的结论,为建立空间电场促进植物生长技术提供理论依据。  相似文献   

8.
本文主要研究在施用尿素条件下,配加氢醌来延缓尿素的集中水解,以减少氨挥发并抑制其硝化作用,从而有效地缓解尿素对大豆共生固氮体系产生的严重抑制效应。结果表明,在一定的浓度范围内,氢醌对纯培养大豆根瘤菌生长。幼苗生长和初生结瘤无不利影响;对离体活性根瘤的呼吸活性和璃珀酸脱氢酶活性具有显著促进。在盆载或田间条件下,尿素配加HQ施用,同无HQ等量尿素比较,显著提高了大豆结瘤量和单株固氮总活性;提高了大豆木  相似文献   

9.
利用OTC-1型开顶式气室进行了CO2浓度倍增对冬小麦影响的诊断试验,结果表明,CO2浓度倍增对冬小麦生长发育、叶面积变化、生物量及产量形成等影响显著,且均为正效应。  相似文献   

10.
为了研究超临界CO2作为非水相介质在生化反应工程中的作用,有必要考察超临界CO2处理对微生物活性的影响。本文以乳酸杆菌为试验菌种,进行了该菌在不同参数超临界CO2处理对菌体生长曲线、耐渗透压能力、耐酸能力、抑菌能力、降解胆固醇能力等活性指标影响的研究。结果表明:当提高超临界CO2压强或延长超临界CO2处理时间,乳酸杆菌的活性指标会发生如下变化:生长曲线的最大菌体浓度降低,但菌体的生长速率差异不大;菌体的耐渗透能力、耐酸能力降低;所得的抑菌圈比较明显,但抑菌圈直径减小;平均胆固醇降解率降低,而且长时间处理对降解效果的影响比高压强处理的明显。因此,在工程应用中需要研究一定的弥补措施。  相似文献   

11.
本文研究了在不同氮素水平下,CCO2倍增对大豆叶片单位鲜重叶绿素(Chl)和类胡萝卜素(Car)含量,以及荧光诱导动力学参数的影响。结果表明,在正常大气下增施氮肥,对叶片Chl含量的提高作用相当于CO2倍增的作用,但是增施氮肥又可进一步强化CO2倍增的作用。CO2倍增和增施氮肥均有改善大豆光合功能的作用,提高大豆的PSⅡ活性和光合作用潜在量子转化效率,提高PSⅡ反应中心开放部分的比例,降低非辐射能量的耗散,使大豆能更充分地利用所捕获的光能用于光合作用,结果促进PSⅡ总的光化学量子产量的提高。增施氮肥同样表现出可增强CO2倍增对光合功能的改善作用。表明要使高浓度的CO2对C3植物光合作用起更好的作用,增施氮肥是必要的。  相似文献   

12.
Soybean (Glycine max L. Merr.) cv. Bragg and its supernodulating mutant nts 1007 were grown in pots containing vermiculite with a N-free nutrient solution in order to examine the effect of elevated CO2 concentration (100+20 Pa CO2 ) on biomass production, photosynthesis, and biological nitrogen fixation. The whole plant weight increase in Bragg was higher than in the mutant at a high CO2 concentration. Apparent photosynthetic activities of the upper leaves in both Bragg and the mutant increased up to 14 d after treatment initiation by the CO2 enrichment and thereafter decreased to some extent. Both leaf area and leaf thickness of Bragg increased more than in nts 1007. With the elevated CO2 concentration, biological nitrogen fixation (BNF) also responded in the same manner as biomass production in both Bragg and nts 1007. The increase of BNF in Bragg was largely due to an increase in nodule weight. Starch contents in the leaves of both Bragg and the mutant increased significantly by CO2 enrichment, with a higher increase in Bragg than in its mutant. Sugar content in leaf differed only slightly in both Bragg and the mutant. N content in leaf decreased in both Bragg and its mutant, with the decrease being more pronounced in Bragg. However, in other plant parts (roots, stem, and petiole + pods), N content increased in the mutant while in Bragg, it decreased in the pod. N accumulation rate was higher in Bragg than in the mutant and increased more in Bragg than in the mutant by CO2 enrichment. The ureide content in leaf decreased in Bragg but increased in the mutant by elevated CO2 concentration. In the nodules, ureide content increased in both Bragg and the mutant by CO2 enrichment. Based on these results, it is suggested that in terms of biomass production and photosynthetic rate, Bragg responded more to elevated CO2 concentration than its mutant nts 1007. The alleviation of the stunted vegetative growth of the mutant by CO2 enrichment was limited despite the significant increase in the photosynthetic activity, presumably due to the limitation of sink activity in the growing parts and not to insufficient supply of N through BNF.  相似文献   

13.
Abstract

The objective of this experiment was to measure the impact of molybdenum (Mo) addition to the soil on changes in rate of photosynthesis (PN), specific root nodule nitrogenase activity (SNA), chlorophyll ‐ (Chl‐a) and (Chl‐b) and biomass of soybean (Glycine max L. Merrill), exposed to carbon dioxide (CO2) (350, 400, or 450 μL/L) for 5 d during its sensitive growth stage (R2). Plants grown in soil with Mo (0, 0.5, or 1.0 mg/kg soil dry weight) were exposed to carbon dioxide (CO2) in open‐top field chambers for 12 h/d for 5 d with a nitrogen (N)‐free fertilizer. Increasing CO2 levels reduced SNA and increased both Chl‐a and Chl‐b. Addition of 1 mg/kg Mo significantiy reduced SNA for plants grown with 350 μL/L CO2 with no change in PN.  相似文献   

14.
Lime is a common amendment to overcome soil acidity in agricultural production systems. However, plant root effects on lime and soil carbon (C) dynamics in acidic soils under varied temperature remain largely unknown. We monitored root effects of soybean on the fate of lime applied to an acidic soil at 20 and 30°C in growth chambers. Soil respired CO2 was continuously trapped in columns without and with plants until the final stage of vegetative growth. Lime‐derived CO2 was separated from total respired CO2 based on δ13C measurements in CO2. Leaching was induced at early and late vegetative growth stages, and the leachates were analysed for dissolved organic (DOC) and inorganic C (DIC) concentrations. Soil respiration significantly increased with lime addition at both temperatures (p < 0.001). The presence of soybean doubled the recovery of lime‐derived CO2‐C at 20°C at the early growth stage; however, by the end of the experiment, the contribution of lime‐derived CO2‐C to soil respiration was negligible in all treatments, indicating that the contribution of lime to soil respiration was shortlived. In contrast, DIC and DOC concentrations in leachates remained elevated with liming and were greater in the presence of soybean. We observed no main temperature effects and no interactive effects of temperature and soybean presence on lime‐derived CO2‐C, DIC and DOC. These results highlight the role of plant‐modulated processes in CO2 release and C leaching from lime in acidic soils, whereas an increase in temperature may be less important. Temperature and plant roots alter the rate of key processes controlling C dynamics in a limed acidic soil. Lime‐derived CO2‐C, DIC and DOC increased more in the presence of plants than with increased temperature. Root effects are more important than temperature for inorganic and organic carbon dynamics in limed acidic soils.  相似文献   

15.
Soybean (Glycine max L. Merr.) cultivars Akisirome and Peking were inoculated with Bradyrhizobium japonicum Is-21 and Rhizobium fredii USDA 194, respectively, and were grown in cylindrical pots containing sterilized vermiculite which were aerated with CO2-free air or ambient air to study the effects of CO2 deficiency in the rhizosphere on plant growth, nodulation, and nitrogen fixation. The repressive effects of CO2-free air treatment were more conspicuous in Peking than Akisirome, and nodule number, nodule mass, amount of biologically fixed N and plant growth of Peking were reduced remarkably by the CO2-free air treatment.

Acetylene reduction activity (ARA) of Peking inoculated with USDA 194 and Akisirome inoculated Is-21 was assayed in the absence and presence of CO2, ARA of Akisirome was not affected by the absence of CO2, while that of Peking decreased drastically.

Based on these results, it was concluded that nitrogen fixation by Akisirome inoculated with B. japonicum Is-21 was not appreciably influenced by CO2 deficiency in the rhizosphere, while that of Peking inoculated with R. fredii USDA 194 was severely repressed, and the decrease was estimated to be due to both the reduction of the nodule mass and specific nitrogen-fixing activity.  相似文献   

16.
Increasing atmospheric carbon dioxide (CO2) concentration could have significant implications on technologies for managing plant nutrition to sustain crop productivity in the future. Soybean (Glycine max [L.] Merr.) (C3 species) and grain sorghum (Sorghum bicolor [L.] Moench) (C4 species) were grown in a replicated split‐plot design using open‐top field chambers under ambient (357 μmol/mol) and elevated (705 μmol/mol) atmospheric CO2. At anthesis, leaf disks were taken from upper mature leaves of soybean and from the third leaf below the head of sorghum for analysis of plant nutrients. Leaf greenness was measured with a Minolta SPAD‐502 chlorophyll meter. Concentrations of chlorophylls a and b and specific leaf weight were also measured. Above‐ground dry matter and seed yield were determined at maturiry. Seed yield of sorghum increased 17.5% and soybean seed yield increased 34.7% with elevated CO2. There were no differences in extractable chlorophyll concentration or chlorophyll meter readings due to CO2 treatment, but meter readings were reduced 6% when sorghum was grown in chambers as compared in the open. Leaf nitrogen (N) concentration of soybean decreased from 54.5 to 39.1 g/kg at the higher CO2 concentration. Neither the chambers nor CO2 had an effect on concentrations of other plant nutrients in either species. Further work under field conditions is needed to determine if current critical values for tissue N in crops, especially C3 crops, should be adjusted for future increases in atmospheric CO2 concentration.  相似文献   

17.
Effect of CO2 enrichment on the carbon-nitrogen balance in whole plant and the acclimation of photosynthesis was studied in wheat (spring wheat) and soybean (A62-1 [nodulated] and A62-2 [non-nodulated]) with a combination of two nitrogen application rates (0 g N land area m-2 and 30 g N land area m-2) and two temperature treatments (30/20°C (day/night) and 26/16°C). Results were as follows.

1. Carbon (dry matter)-nitrogen balance of whole plant throughout growth was remarkably different between wheat and soybean, as follows: 1) in wheat, the relationship between the amount of dry matter (DMt) and amount of nitrogen absorbed (Nt) in whole plant was expressed by an exponential regression, in which the regression coefficient was affected by only the nitrogen application rate, and not by CO2 and temperature treatments, and 2) in soybean the DMt-Nt relationship was basically expressed by a linear regression, in which the regression coefficient was only slightly affected by the nitrogen treatment (at 0N, DMt-Nt balance finally converged to a linear regression). Thus, carbon-nitrogen interaction in wheat was strongly affected by the underground environment (nitrogen nutrition), but not by the above ground environment (CO2 enrichment and temperature), while that in soybean was less affected by both under and above ground environments.

2. The photosynthetic response curve to CO2 concentration in wheat and soybean was less affected by the CO2 enrichment treatment, while that in wheat and soybean (A62-2) was affected by the nitrogen treatment, indicating that nitrogen nutrition is a more important factor for the regulation of photosynthesis regardless of the CO2 enrichment.

3. Carbon isotope discrimination (..:1) in soybean was similar to that in wheat under ambient CO2, while lower than that in wheat under CO2 enrichment, suggesting that the carbon metabolism is considerably different between wheat and soybean under the CO2 enrichment conditions.  相似文献   

18.
An experiment was conducted to examine the effect of CO2 enrichment on the nitrate uptake, nitrate reduction activity, and translocation of assimilated-N from leaves at varying levels of nitrogen nutrition in soybean using 15N tracer technique. CO2 enrichment significantly increased the plant biomass, apparent leaf photosynthesis, sugar and starch contents of leaves, and reduced-N contents of the plant organs only when the plants were grown at high levels of nitrogen. A high supply of nitrogen enhanced plant growth and increased the reduced-N content of the plant organs, but its effect on the carbohydrate contents and photosynthetic rate were not significant. However, the combination of high CO2 and high nitrogen levels led to an additive effect on all these parameters. The nitrate reductase activity increased temporarily for a short period of time by CO2 enrichment and high nitrogen levels. 15N tracer studies indicated that the increase in the amount of reduced-N by CO2 enrichment was derived from nitrate-N and not from fixed-N of the plant. To examine the translocation of reduced-N from the leaf in more detail, another experiment was conducted by feeding the plants with 15NO3-N through a terminal leaflet of an upper trifoliated leaf under depodding and/or CO2 enrichment conditions. The export rate of 15N from the terminal leaflet to other plant parts decreased by depodding, but it increased by CO2 enrichment. CO2 enrichment increased the percentage of plant 15N in the stem and / or pods. Depodding increased the percentage of plant 15N in the leaf and stem. The results suggested that the increase in the leaf nitrate reduction activity by CO2 enrichment was due to the increase of the translocation of reduced-N from leaves through the strengthening of the sink activity of pods and / or stem for reduced-N.  相似文献   

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