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1.
Twenty soybean cultivars from maturity groups IV, V, VI, VII and VIII were screened in the growth chamber study to determine their response to two Rhizobium strains through N-fixation rates. Cultivars Lee 74, Essex and Bay showed high nitrogenase activities of 201.00, 93.75 and 74.86 nM C2 H2 /pl/hr, respectively. Braxton, Hutton and Bragg showed low nitrogenase activity rates of 4.73, 4.20 and 3.0 nM C2 H2 /pl/hr, respectively. A range of variation was found among the cultivars in shoot fresh and dry weights, nodule number and nodule weight. 相似文献
2.
综述了臭氧（O3）浓度升高、太阳辐射减弱、UV-B辐射、CO2浓度升高及其与O3复合作用对植物形态特征、光合作用、干物质累积及作物产量等生理生化机制的影响。交互作用的试验条件可以更好地模拟自然环境条件。O3和UV-B辐射对植物几乎没有积极作用。太阳辐射减弱、CO2浓度升高都会促进植物营养生长。但太阳辐射减弱降低干物质累积和产量,CO2浓度升高对其有促进作用。CO2浓度升高在与O3复合条件下,可部分缓解太阳辐射减弱对植物造成的伤害。而UV-B辐射与O3复合对植物造成的伤害更大。 相似文献
3.
Eighteen soybean ( Glycine max [L.] Merr) cultivars from maturity groups V and VI were screened with two Bradyrhizobium japonicum strains (USDA 110 and TAL 378) in the greenhouse to determine N2 fixation (C2 H2: reduction) rates. Antibiotic resistant markers were used for observing nodule occupancy. Cultivars L.-76-0132, PI 159319, Hoberland, Lee, PI 22173 and Centennial showed high nitrogenase activity of 6.25, 5.54, 17.43, 4.73, 6.94, and 4.81 μM C2 H4 /Pl/hr, respectively. Cultivars PI417419, PI 230978, Ogden , and FC 31665 showed low nitrogenase activity of 1.51, 0.80, 0.62 and 0.94 μM C2 H4 /Pl/hr, respectively. The data from this screening experiment suggest that the N2 fixation varied among genotypes and all the nodules were occupied by the inoculated strains only. Rhizobial strain effect was observed among soybean cultivars (MGVI). 相似文献
4.
Field bean planes cultivar Nadwiślański were submitted to soil drought (30 % of field soil water capacity) for 5 days at the stage of pod formation (A) and of rapid pod growth (B) and then exposed for 20 minutes to 14 CO2 . Radioactivity of leaves, stems, roots, and pods or pod shells and seeds was measured 1, 5, 24 and 48 hours after exposition.
In both stages soil drought reduced by about five times total CO2 assimilation, mainly owing to lower activity of the photosynthetic apparatus and also, though less so, to reduced leaf growth. Photosynthetic activity referred to the dry weight of the leaves dropped to 22-35% of controls. Accumulation of photosynthetates in generative organs was much less depressed than 14 CO2 assimilation. 48 hours after exposition to 14 CO2 of drought treated plants, the contents of 14 C of pods in phase A, and seeds in phase B, amounted to respectively 24% and 36% of assimilated 14 C and equalled 91.5% and 74% of the corresponding values for controls.
The progressive decline of radioactivity in leaves and stems after14 CO2 exposition was distinctly correlated to the rise of radioactivity of generative organs both in soil drought treated plants and in controls. Slightly lower values of correlation coefficients in drought treated plants may indicate impairment under drought conditions of synchronization in processes of unloading and accumulation of assimilates.
In plants drought treated in phase A the ability to dissimilate14 C was reduced to about 59% of that in controls, but when drought was applied in phase B, dissimilation rate was about three times as high. 相似文献
In both stages soil drought reduced by about five times total CO
The progressive decline of radioactivity in leaves and stems after
In plants drought treated in phase A the ability to dissimilate
5.
地表太阳紫外线-B（UV-B，波长：280~320 nm）辐射增强和气候变化均是当今重要的全球性环境问题。平流层臭氧层损耗以及大气CO2、CH4和N2O等温室气体排放的增加，是驱动这两大全球性问题的主要因素。UV-B辐射增强会通过一系列的生物地球化学进程影响陆地生态系统碳氮平衡，改变CO2、CH4、N2O等温室气体的排放，进一步对气候变化产生作用。笔者对UV-B辐射增强对陆地生态系统CO2排放的影响途径（凋落物和土壤）和影响机制（有机物中难降解分子转化为可溶性有机碳、有机物非生物光化学降解以及光引发产生的微生物降解）进行了总结，阐述了UV-B辐射增强对CH4和N2O排放的影响途径（植株组织化学结构变化和根系分泌物组分变化），及其在不同生态系统中与环境要素相互作用下的排放规律。此外，气候变化背景下，一定范围内的温度升高和降水量减少可促进UV-B辐射增强产生的有机物光降解作用，进而促进温室气体的排放。目前，UV-B辐射增强对陆地生态系统的影响研究相对较缺乏，大都集中在干旱生态系统，且定量研究较少。今后需更多长期、大规模的野外实地研究，并结合模型来准确估计UV-B辐射增强对陆地生态系统温室气体排放的贡献。本论文可为全球变化背景下精准预测温室气体排放提供参考。 相似文献
6.
W. H. Wei S. F. Zhang L. J. Wang J. LI B. Chen Z. Wang L. X. Luo X. P. Fang 《Plant Breeding》2007,126(4):392-398
By intergeneric sexual hybridization between Sinapis alba and Brassica oleracea , F1 , F2 and BC1 progeny plants were produced. S. alba plants (genome SS, 2n = 24) were pollinated with B. oleracea (genome CC, 2n = 18), and the fertile F1 plants were pollinated with B. oleracea to obtain BC1 plants. GISH analysis showed that 10 out of 12 F1 plants had 12 S. alba chromosomes (one full S chromosome set) and nine B. oleracea chromosomes (one C chromosome sets), representing the expected hybrids. However, two F1 plants had 12 S chromosomes and 18 C chromosomes (two C chromosome sets), indicating unexpected hybrids. A maximum of three trivalents between C and S chromosomes were identified at metaphase I of semi-fertile F1 pollen mother cells (PMCs), which indicates homology and chromosome pairing between these two genomes. The C genome had obviously been doubled in two F2 plants from selfed semi-fertile F1 plants. BC1 plants consisted of 18 C chromosomes and different numbers of one, five and six additional S chromosomes, respectively. Monosomic alien addition lines developed in the present study can be used for B. oleracea breeding and Sinapis alba gene mapping. 相似文献
7.
A versatile method was developed for the application of 1000 ppm CO2 during the whole growth period of plants. Temperature controlled water cooling and ventilation of the greenhouse resulted in a monthly CO2 enrichment time of 60 to 90 % of the total light period. Digitalis lanata , grown in greenhouses with CO2 enrichment during the whole growth phase from April to November, produced twice as much biomass as field cultivated plants.
The relative yield of the glycoside digoxin per gram Digitalis drug dry weight was 0.4% in field grown and 0.7% in greenhouse cultivated plants. The production of digoxin per hectare in the greenhouse at 1000 ppm CO2 was almost 3.5-fold that by field cultivation. Drug yield and secondary metabolite production in D. lanata were remarkably influenced by increased temperature and elevated CO2 partial pressure in the greenhouse. 相似文献
The relative yield of the glycoside digoxin per gram Digitalis drug dry weight was 0.4% in field grown and 0.7% in greenhouse cultivated plants. The production of digoxin per hectare in the greenhouse at 1000 ppm CO
8.
Seasonal Changes in the Photosynthetic Capacity of Winter Rape Plants under Different Nitrogen Regimes Measured in the Field 总被引：1，自引：0，他引：1
Winter rape (cv.'Falcon') grown under different nitrogen regimes (N0 , N120 ; 0 and 120 kg.ha−1 , respectively) in northern Germany was investigated over the 1996 spring–summer season. Using a CO2 , H2 O diffusion porometer, diurnal courses or net photosynthesis and respiration were measured in situ and were related to microclimatic conditions and leaf water relations. Photosynthesis was modelled and daily CO2 gain was calculated. In contrast to the N120 plants, plants of the low nitrogen plot (N0 ) grew less densely and their leaves behaved more like sun leaves. Increased nitrogen supply had little influence on photosynthetic capacity but it increased productivity through higher leaf area index and an extended period of photosynthetic activity. N120 plants also appeared to be better acclimated to hot, summer conditions. Higher nitrogen supply substantially increased seed production with the yield of the N120 plants being 16% of the N0 plants. 相似文献
9.
Water Relations, Abscisic Acid and Yield of Wheat Plants in Relation to the Interactive Effect of Seawater and Growth Bioregulators 总被引：4，自引：0，他引：4
Irrigation of wheat plants with seawater (10 and 25 %) led to significant increases in free and bound abscisic acid (ABA) in leaves, especially at 25 %. The relative water content (RWC) and water use efficiency (calculated from grain yield, WUEG , or from biomass yield, WUEB ) of the seawater-irrigated plants were lower than those of the control. Grain pre-soaking in gibberellic acid (GA3 ), indole-3-acetic acid (IAA) or ABA reduced the levels of accumulated ABA (free and bound) produced by seawater irrigation. The stress imposed by seawater generally reduced yield and yield components of wheat plants and the effect was more pronounced at the higher level of seawater irrigation (25 %). Furthermore, seawater treatments decreased the carbohydrate content and increased the protein content of the developing grains. The effect of seawater treatments on ion concentrations in the developing grains was not consistent. The application of growth bioregulators appeared to mitigate the effect of seawater salinity stress on wheat productivity. GA3 was the most effective hormone in this regard. The economic yield (grain yield) had a strong positive correlation with RWC, WUEG , WUEB , plant height, shoot fresh and dry weight, grain number/main spike, kernel weight and harvest index. 相似文献
10.
The effects of ultraviolet-B (UV-B) radiation on the physiological characteristics of nitrogen metabolism were examined in two transgenic Bt cotton cultivars, 29317 and 29312, under hydroponic conditions. UV-B was artificially applied via filtered lamps at three levels: 0(CK), 2.7 and 5.4 kJ·m-2·d-1. Our results showed that UV-B radiation decreased shoot dry weight, but had no impact on root dry weight accumulation. At 2.7 kJ·m-2·d-1 UV-B radiation, no significant difference in total nitrogen content compared with the control was observed. However, high levels of UV-B radiation at 5.4 kJ·m-2·d-1 significantly increased the total nitrogen content. Further physiological studies revealed that UV-B radiation upregulated nitrate reductase activity, glutamine synthetase activity, protease activity, and peptidase activity. Higher contents of soluble protein and total free amino acids were induced by UV-B radiation. The results suggested that UV-B radiation promoted protein synthesis and degradation, which accelerated nitrogen metabolism in cotton seedlings. Enhanced nitrogen metabolism may be a protective response to UV-B radiation damage. 相似文献
11.
J. Müller 《Journal of Agronomy and Crop Science》1993,171(4):217-235
Dry Matter Production, CO2 Exchange, Carbohydrate and Nitrogen Content of Winter Wheat at Elevated CO2 Concentration and Drought Stress
Methods of mathematical modelling and simulation are being used to an increasing degree in estimating the effects of rising atmospheric CO2 concentration and changing climatic conditions on agricultural ecosystems. In this context, detailed knowledge is required about the possible effects on crop growth and physiological processes. To this aim, the influence of an elevated CO2 concentration and of drought stress on dry matter production, CO2 exchange, and on carbohydrate and nitrogen content was studied in two winter wheat varieties from shooting to milk ripeness. Elevated CO2 concentration leads to a compensation of drought stress and at optimal water supply to an increase of vegetative dry matter and of yield to the fourfold value. This effects were caused by enhanced growth of secondary tillers which were reduced in plants cultivated at atmospheric CO2 concentration. Analogous effects in the development of ear organs were influenced additionally by competitive interactions between the developing organs. The content and the mass of ethanol soluble carbohydrates in leaves and stems were increased after the CO2 treatment and exhausted more completely during the grain filling period after drought stress. Plants cultivated from shooting to milk ripeness at elevated CO2 concentration showed a reduced response of net photosynthesis rate to increasing CO2 concentration by comparison with untreated plants. The rate of dark respiration was increased in this plants. 相似文献
Methods of mathematical modelling and simulation are being used to an increasing degree in estimating the effects of rising atmospheric CO
12.
有害中波紫外线(Ultraviolet B, UV-B; 280~320 nm)辐射影响植物的生长和发育, Ca 2+是植物生长发育所必须的大量元素之一, 外源Ca 2+不但可以提高植物抗胁迫能力, 还对次生代谢具有调控作用。以颠茄(Atropa belladonna L.)实生苗为材料, 在UV-B辐射(10 μW cm -2)背景下, 研究不同浓度外源Ca 2+、不同处理时间对颠茄生理特性、氮代谢、次生代谢产物含量以及托品烷类生物碱代谢途径中3个关键酶基因表达量的影响。结果表明, 随着UV-B辐射时间的延长(4 ~12 d), 对颠茄的光合作用、氮代谢以及生物碱的积累产生抑制作用, 加剧了膜脂氧化程度; 经外源Ca 2+处理, 叶片初始荧光(Fo)、丙二醛(malondialdehyde, MDA)含量呈下降趋势, 叶片最大光化学效率(Fv/Fm)、光合色素(总叶绿素、类胡萝卜素)含量、抗氧化酶(SOD、POD、CAT)活性均呈上升趋势, 说明Ca 2+有利于缓解UV-B辐射的抑制, 加强对UV-B胁迫的抗性; 在Ca 2+处理下, 叶片中硝态氮含量显著降低, 游离氨基酸、可溶性蛋白含量和氮代谢关键酶(NR、GS、GDH)的活性显著提高, 叶片中莨菪碱含量和东莨菪碱含量显著提高; qRT-PCR分析显示, 在外源Ca 2+的诱导下, 托品烷类生物碱合成途径中3个关键酶基因(PMT、TR I、H6H)表达量均有不同程度上调趋势。本研究结果可为田间种植提供理论参考。 相似文献
13.
The effects of exposure in the vegetative phase of growth to 5- or 10-day spells of soil drought (30% field water capacity) on assimilation, dissimilation and accumulation of 14 C and on dry matter growth were studied in two maize hybrids, nos. 8344 and 8388 (Garst Seed Co.) of high and low drought tolerance. Under control water regime in soil there was no difference in 14 CO2 uptake and dry matter growth between hybrids. After five days of drought 14 CO2 assimilation dropped by about 75% referred to unit weight of dry matter in hybrid 8344 and by 56% in hybrid 8388. After 10 days of drought 14 CO2 assimilation rate was reduced by 75% in both hybrids. Soil drought increased the 14 C dissimilation. There were no significant differences between hybrids in all treatments, with the exception of 5 days drought; after this treatment the dissimilation rate of hybrid 8344 was higher than that of 8388. Changes of translocation of 14 C and its accumulation in particular organs occurred in drought treated plants; the amount of 14 C accumulated in roots of plants of hybrid 8344 increased, while that of hybrid 8388 decreased. Changes of 14 C accumulation in roots were positively correlated to changes of dry matter of those organs. One day after 10 days of drought assimilation and dissimilation rates in both hybrids were about 60% of controls. 相似文献
14.
The response of Brassica juncea var. Bio-183-92 to elevated CO2 under increased nitrogen treatment was studied. There was an interactive effect of CO2 and nitrogen nutrition, indicating that, on the addition of more nitrogen, the plants sustained the positive effect of CO2 enrichment by utilizing additional carbohydrates for the development of new sinks. Excess carbohydrate enables plants to be flexible and responsive to additional nitrogen application to sustain the CO2 enrichment effect. 相似文献
15.
Intergeneric F1 hybrids between Raphanus sativus (2n = 18, RR) and Moricandia arvensis (2n = 28, MaMa) have been produced through ovary culture followed by embryo culture, when M. arvensis was used as a pistillate parent. Six BC1 plants were also obtained through ovary culture followed by embryo culture in the backcross of an amphidiploid F1 , hybrid with R. sativus cv. 'Pink ball'. Two BC1 plants were ses-quidiploids (2n = 32, MaRR), and the other BC1 , plants were hyperploid with 2n = 55, having MaMaRRR genomes. BC2 , seeds were obtained by conventional pollination in the successive backcross of two sesquidiploid BC1 , plants with R. sativus cv. 'Pink ball'. Their seed set percentages were 12.7% and 17.0%, respectively. These novel hybrid plants and derived progenies may be valuable materials for the genetic investigation and breeding of Brassiceae , including R. sativus. 相似文献
16.
Field trial studies were carried out to find out whether performance of soybean could be improved as a result of pre-sowing soaking treatment of seeds. Comparatively pre-sowing seed treatment with KNO3 , NaNO3 , NaCl, thiourea and di-Ammonium phosphate (DAP) resulted in better development of the root and shoot system than the control. As a result of pre sowing seed treatment, there was an increase in dry matter production by 44, 27 and 32 % over the control in KNO3 , NaNO3 and DAP treatments respectively. Similarly increase in seed yield was noticed in NaNO3 (45 %), KNO3 (40 %) and DAP (50 %) pretreated plants. The number of existing nodules was reduced both in the control and treated plants due to pH (8.4) of the soil.
To investigate the cumulative effects of foliar spray on plants raised from pre-sowing seed treatment, salt solutions (NaCl, KNO3 , NaNO3 , thiourea, DAP) at optimal level were sprayed separately three times at three different stages of development. As a result of foliar spray moderate increase in growth in KNO3 (20 %), thiourea (29 %) and DAP (25 %) treatment was observed over the control. Seed yield increased significantly (56–70 %) in all treatments except NaCl spray, due to increase in the number of pods (41–63 %) per plant. Foliar spray of nutrients increased protein yield without affecting the oil content. It is suggested that a considerable fertilizer economy may be effected by coupling pre-sowing seed treatment with foliar fertilization. 相似文献
To investigate the cumulative effects of foliar spray on plants raised from pre-sowing seed treatment, salt solutions (NaCl, KNO
17.
An attempt has been made to study the interactive effect of elevated CO2 and moisture stress on photosynthesis, growth and water relations of Brassica species using open top chambers. It was observed that plants responded to elevated CO2 significantly under moisture stress condition mitigating the adverse effects on photosynthesis and growth of Brassica species. Relatively drought susceptible species, viz. B. campestris and B. nigra , responded to elevated CC2 markedly as compared to less sensitive B. carinata and B. juncea plants. The water status of plants significantly improved under elevated CO2 concentration possibly by increasing stomatal resistance and/or by increased root growth. 相似文献
18.
Field studies were conducted during the winter seasons of 1995–96 and 1996–97 at the Agricultural Farm of Aligarh Muslim University, Aligarh, India on mustard ( Brassica juncea L. Czern & Coss., var. Alankar) under non-irrigated conditions, to evaluate the effect of foliar spray of 200 p.p.m. ethrel (2-chloroethyl phosphonic acid) at flowering growth stage along with basal 0, 40, 80 or 120 kg N ha−1 on net photosynthetic rate (PN ), stomatal conductance (CS ), stomatal resistance (RS ), leaf K content, relative water content (RWC), leaf area index (LAI) and total dry matter (TDM) production monitored at 20 days after spray application, and plant N content, seed N content, nitrogen harvest index (NHI), nitrogen yield merit (NYM), pods plant−1 , 1000 seed weight, seed yield, biological yield, harvest index (HI), seed yield merit (SYM) and merit of genotype (MOG) at harvest. Results indicated that, at 0 or 40 kg N ha−1 , ethrel did not produce any significance effect, but at basal 80 kg N ha−1 , ethrel affected the parameters favourably with the exception of 1000 seed weight, HI, seed N and NHI. Ethrel-sprayed plants utilized N from the soil more effectively and showed increased NYM. Yield attributes, seed yield and merit of genotype (in terms of NYM and SYM) were also enhanced. Ethrel spray enhanced seed yield under water stress conditions mainly by increasing K uptake and retaining higher RWC, thereby decreasing RS and increasing LAI, PN and TDM production. 相似文献
19.
Two experiments of soil N-fertilization and Rhizobium inoculation were conducted in 1981 and 1982 at Giza, Egypt. Soybean was sprayed with a commercial micronutrients mixture, and with urea.
In the first experiment, soil N-fertilization 0, 142.8 and 214.2 kg N/hectare were applied to uninoculated plants, whereas, in the second one, local inoculum was used alone or along with addition of a starter dose of N (47.6 kg N/hectare).
Urea applications were at pod filling period (R4 , R5 and R6 stages), whereas, micronutrients mixture was applied at 25 days from planting.
Plant dry weight, leaf area/plant, plant height, pod and seed number/plant, seed weight/plant, seed yield and crude seed protein content increased significantly with nitrogen application to uninoculated soybean plants; whereas the starter dose of N had no significant effect on any of these traits under the inoculated soybean plants.
Foliar application of micronutrients caused significant increases in plant DW, LA, pod and seed number/plant, seed index and seed yield of fertilized and inoculated plants.
Foliar application of urea, to inoculated and uninoculated plants, caused significant increments in plant dry weight, 1A, seed protein content and particular seed index and seed yield. 相似文献
In the first experiment, soil N-fertilization 0, 142.8 and 214.2 kg N/hectare were applied to uninoculated plants, whereas, in the second one, local inoculum was used alone or along with addition of a starter dose of N (47.6 kg N/hectare).
Urea applications were at pod filling period (R
Plant dry weight, leaf area/plant, plant height, pod and seed number/plant, seed weight/plant, seed yield and crude seed protein content increased significantly with nitrogen application to uninoculated soybean plants; whereas the starter dose of N had no significant effect on any of these traits under the inoculated soybean plants.
Foliar application of micronutrients caused significant increases in plant DW, LA, pod and seed number/plant, seed index and seed yield of fertilized and inoculated plants.
Foliar application of urea, to inoculated and uninoculated plants, caused significant increments in plant dry weight, 1A, seed protein content and particular seed index and seed yield. 相似文献
20.
B. Sasmal 《Journal of Agronomy and Crop Science》1987,159(4):260-263
The direct and indirect contributions of root characters — root length, roots/plant, fresh and dry root weight on grain yield/plant were worked out from a 7 × 7 diallel set of rice hybrids. The materials were grown in pots with four replications. Path analysis was done at genotypic level of correlation.
The grain yield/plant showed positive correlation with all the root characters in parent, F1 and F2 except with roots/plant in F1 population. Fresh root weight demonstrated positive direct effect on grain yield/plant in all the three generations. Roots/plant had highly positive direct effect in F2 . Direct effects were negative in respect of root length and dry root weight in F2 generation. 相似文献
The grain yield/plant showed positive correlation with all the root characters in parent, F