首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 46 毫秒
1.
Summary Bradyrhizobium japonicum strain G49 has been the only inoculum used in French soils. Soybean (Glycine max L. Merr.) cultivars were selected and tested according to their performances with this rhizobial strain. The aim of the present study was to determine the consequences of strain substitution on N2 fixation abilities of various genotypes. Three genotypes and cultivar Weber, in combination with B. japonicum strain G49 or SMGS1, were cultivated in pots and tested for nitrogenase activity under differing nitrogen nutrition conditions. The reliability of ARA (acetylene reduction activity) measurement for assessing symbiotic nitrogen fixation under the experimental conditions used was checked. Genotypic variability for symbiotic fixation activity was observed with each strain under soil culture conditions; important genotype x strain interactions were also involved. These results were corroborated for the protein yield and other yield component performances of the various genotype-strain associations. Thus, in France, the replacement of strain G49 with another one might result in the alteration of the relative agronomic performances of the soybean cultivars, since N2 fixation is considered as a major factor of soybean productivity.  相似文献   

2.
A. Zougari    S. Guy  C. Planchon 《Plant Breeding》1995,114(4):313-316
Decreasing the lipoxygenase content of soybean (Glycine max (L.) Merr.) seed is a prerequisite for its increased use in human foods. These investigations aim to analyse the variation of lipoxygenase contents in relation to the genotype or the nitrogen nutrition of the plant. Four genotypes from a divergent selection for N2 fixation and the recurrent parent, Weber, were grown in pots, and two Bradyrhizobium japonicum strains (G.49 and SMGS1) were used. Dinitrogen fixation was estimated in situ using the acetylene–reduction assay. The lipoxygenase activity was determined polarographically on seeds taken from plants grown under controlled conditions in the presence or absence of symbiotic N2 fixation. The large genotypic variation observed for the lipoxygenase contents was enhanced by high N2 fixation. The variation range of lipoxygenase contents, which was obtained through the combination of the genotypic variation and the N2 fixation activity, was relatively large with a ratio of 2 on a seed dry–weight basis and a ratio of 2.6 when the total proteins were considered. Decreased lipoxygenase content and increased total protein content can thus be considered in parallel in a genetic context, together with more efficient N2 fixation.  相似文献   

3.
The effects of deep placement (supplied at 20 cm depth from soil surface below plants) of 100 kg N ha?1 of N fertilizers, urea, coated urea or calcium cyanamide (lime nitrogen) on the growth, nitrogen fixation activity, nitrogen absorption rate and seed yield of soybean (Glycine max L. Merr.) plants were examined by comparing them with control plots without deep placement of N fertilizer in sandy dune field. In addition, three different inoculation methods of bradyrhizobia were used for each N treatment: (1) transplantation of 10‐day‐old seedling in a paper pot with vermiculite inoculated with Bradyrhizobium japonicum USDA110, (2) direct transplantation of inoculated 10‐day‐old seedlings, and (3) transplantation of 10‐day‐old seedlings in a non‐inoculated paper pot. The deep placement of N fertilizers, especially calcium cyanamide and coated urea, markedly increased the growth and total N accumulation in shoot, roots and nodules, which resulted in an increase in seed yield. Daily N2 fixation activity and N absorption rate were estimated by relative abundance of ureide‐N analysed from the concentration of N constituents (ureide‐N, amide‐N and nitrate‐N) in root bleeding xylem sap and increase in total N accumulation in whole plants at R1, R3, R5 and R7 stages. The total amount of N2 fixation was about 50 % higher in the plants with calcium cyanamide and coated urea deep placements compared with control plants. Deep placement of slow release fertilizers kept nodule dry weight higher in the maturing stage of seed, possibly through abundant supply of photoassimilate to the nodules by supporting leaf area and activity until late reproductive stages. The results indicate that deep placement of calcium cyanamide or coated urea enhances N2 fixation activity, which ultimately increases the seed yield. The promotive effect was observed with the seedlings transplanted in paper pot with inoculum of bradyrhizobia within any treatments, although nodulation by indigenous rhizobia was observed in the plants transplanted with non‐inoculated paper pot.  相似文献   

4.
In areas where ineffective nodulation may be a problem, ‘starter’ nitrogen fertilization is often suggested as a useful management tool to sustain ineffectively nodulated seedling alfalfa (Medicago sativa L.) until an effective population of Rhizobium can develop. Although ineffective nodulation has been reported from several locations around the world, there have been no studies examing this possibility. A field experiment was conducted during 1982 and 1983 on a Woodburn silt loam soil (Aquultic Argixeroll) which contained a symbiotically ineffective native population of Rhizobium meliloti Dang. This study examined the residual and interactive effects of preplant N fertilizer (0, 45, 90 kg N ha?1) and inoculation on the N nutrition and yield of seedling alfalfa during the first year of growth. The sustaining effects of the fertilizer N were transient and resulted in decreased N2 fixation until 35 days following harvest. It was concluded that during the establishment year, managerial emphasis should be placed on inoculation and not on N fertilization to obtain a consistent, economical source of N for herbage protein and dry matter production.  相似文献   

5.
F. B. Holl 《Euphytica》1975,24(3):767-770
Summary The contribution of the host plant genome in symbiotic dinitrogen fixation has received little attention. In examining more than two thousand samples from the USDA Plant Introduction Collection, host-determined genetic variation in dinitrogen fixation has been found. In genetic analysis of a mutant line of Pisum resistant to nodulation, two genes designated Sym 2 and Sym 3 have been detected; Sym 2 affects nodulation while Sym 3 influences fixation. The two genes segregate independently as dominant Mendelian characters. Effective symbiosis requires the presence of at least one dominant gene at each locus.NRCC No. 146 96Preliminary report of some of this data has been made at the International Symposium on Nitrogen Fixation. Pullman. Washington, June 1974.  相似文献   

6.
The short-term effects of nitrate on symbiotic nitrogen fixation were studied in six cultivars of pea (Pisum sativum L.) using two strains of Rhizobium leguminosarum. Plants grown symbiotically for three weeks, in order to eliminate the effect of NO3 on nodule formation, were exposed to nil, 5 or 15 mM NO3 for a period of seven days. Nodule mass, nitrogenase activity by acetylene reduction and the NO2 and NO3 concentrations in nodules were determined. Exposure to nitrate reduced the total acetylene reduction activity (ARA) in all cultivars, and a significant cultivar × nitrate treatment interaction was found. Nitrate influenced the components of N2 fixation, nodule mass and specific ARA (ARA/mg nodule), differently within and among cultivars. Nodule mass was reduced in all cultivars, but a variation among cultivars in the degree of reduction was found. Nitrate also reduced the specific ARA to different extents in the cultivars- The specific ARA of nodules from NO3-treated plants, expressed as per cent of the specific ARA of nodules from plants grown without NOT3 was negatively correlated with the concentration of NO3 in nodules. No relationship was found between the reduction of N2 fixation and the nitrite concentration in nodules. The results indicate that it is possible to improve the nitrate tolerance of symbiotic N2 fixation of the established pea/Rhizobium symbiosis by selection of suitable host plants.  相似文献   

7.
The relationship between biomass production and N2 fixation under drought‐stress conditions in peanut genotypes with different levels of drought resistance is not well understood. The objective of this study was to determine the effect of drought on biomass production and N2 fixation by evaluating the relative values of these two traits under well watered and water‐stress conditions. Twelve peanut genotypes were tested under field conditions in the dry seasons of 2003/2004 and 2004/2005 in north‐east Thailand. A split‐plot design with four replications was used. Main‐plot treatments were three water regimes [field capacity (FC), 2/3 available soil water (AW) and 1/3 AW], and sub‐plot treatments were 12 peanut lines. Data were recorded on biomass production and N2 fixation under well watered and water‐stress conditions. Genotypic variations in biomass production and N2 fixation were found at all water regimes. Biomass production and N2 fixation decreased with increasing levels of drought stress. Genotypes did not significantly differ in reductions for biomass production, but did differ for reductions in N2 fixation. High biomass production under both mild and severe drought‐stress conditions was due largely to high potential biomass production under well‐watered conditions and, to a lesser extent, the ability to maintain high biomass production under drought‐stress conditions. High N2 fixation under drought stress also was due largely to high N2 fixation under well‐watered conditions with significant but lower contributions from the ability to maintain high nitrogen fixation under drought stress. N2 fixation at FC was not correlated with the reduction in N2 fixation at 2/3 AW and 1/3 AW. Positive relationships between N2 fixed and biomass production of the tested peanut genotypes were found at both levels of drought stress, and the relationship was stronger the more severe the drought stress. These results suggested that the ability to maintain high N2 fixation under drought stress could aid peanut genotypes in maintaining high yield under water‐limited conditions.  相似文献   

8.
  相似文献   

9.
This study aimed to evaluate the ability of Piriformospora indica to colonize the root of Chenopodium quinoa and to verify whether this endosymbiont can improve the growth, performance and drought resistance of this species. The study delivered, for the first time, evidence for successful colonization of P. indica in quinoa. Hence, pot experiment was conducted in the greenhouse, where inoculated and non‐inoculated plants were subjected to ample (40%–50% WHC) and deficit (15%–20%WHC) irrigation treatments. Drought adversely influenced the plant growth, leading to decline the total plant biomass by 74%. This was linked to an impaired photosynthetic activity (caused by lower gs and Ci/Ca ratio; stomatal limitation of photosynthesis) and a higher risk of ROS production (enhanced ETR/Agross ratio). P. indica colonization improved quinoa plant growth, with total biomass increased by 8% (controls) and 76% (drought‐stressed plants), confirming the growth‐promoting activity of P. indica. Fungal colonization seems to diminish drought‐induced growth hindrance, likely, through an improved water balance, reflected by the higher leaf ψw and gs. Additionally, stomatal limitation of photosynthesis was alleviated (indicated by enhanced Ci/Ca ratio and Anet), so that the threat of oxidative stress was minimized (decreased ETR/Agross). These results infer that symbiosis with P. indica could negate some of the detrimental effects of drought on quinoa growth, a highly desired feature, in particular at low water availability.  相似文献   

10.
The nitrogen (N2)‐fixing bacterial inoculant strain for soybean [Glycine max (L.) Merrill] is not indigenous to South African soils. The interaction between soybean genotype, soil type and inoculant strain, however, has a definite influence on soybean production and compatibility should be optimized. This paper reports a growth chamber study using three different soybean genotypes (Barc‐9, Avuturda and Talana), three Bradyrhizobium japonicum inoculant strains (WB108, WB112 and WB1) and three soil types (Avalon, Arcadia and sand) to evaluate the effectiveness of N2 fixation by different genotype × soil type × inoculant strain combinations, using different measuring parameters. These parameters included nodule fresh mass (NFM), amount of N2 fixed (Pfix), as determined by the ureide method, seed protein content (SPC), average seed mass per plant (SMP) and average foliar N content (FNC). The comparison amongst the three‐way interactions, genotype × soil type × inoculant strain, did not differ significantly for the parameters used. Significant two‐way interactions were soil × inoculant for FNC, Pfix and SMP; soil × genotype for FNC and SMP, and inoculant × genotype for FNC (P < 0.05). The soil × inoculant strain interaction was significant for Pfix (P < 0.05). NFM, Pfix, FNC, SMP and SPC correlated positively with soil pH and negatively with soil clay content and soil NO3– and NH4+ content (P < 0.05). SPC was significantly different (P < 0.05) for soil type, genotype and inoculant strain. Pfix and NFM did not reflect the protein content of the seeds, indicating that nodule evaluation should be used with caution as a N2 fixation parameter. Low soil pH and high mineral N content inhibited N2 fixation. NFM correlated negatively with the clay content of the soil. This finding confirms that soybean production in South Africa can be improved by appropriate selection of genotypes and inoculant strains for their compatibility in different soils.  相似文献   

11.
Free‐living nitrogen (N) fixation can be important for sustainable soil fertility, particularly in extensively managed soils with low abundance of leguminous plant species. However, the factors affecting free N2‐fixation in situ are still poorly documented. We investigated the role of microbial active biomass activity, particularly substrate‐induced respiration (SIR) and net N mineralization, on the free‐living N2 fixation in soils under a semi‐natural grassland ecosystem in France. Analysis of replicated bulk soil and rhizospheric soil samples obtained from sites experiencing contrasting grazing regimes revealed highly significant negative relationships (P < 0.01) between free‐living N2‐fixation and SIR or N‐mineralization with a significant rhizosphere effect. The study has demonstrated that the activity of free‐living N2‐fixers is more important in soils having low active microbial biomass and low N‐mineralization rates in these permanent grasslands.  相似文献   

12.
Efficient management of legumes in order to maximize benefits depends on a correct field assessment of N2 fixation. A field experiment was conducted during a 6-year period (2001–2002 to 2006–2007) in Córdoba (Southern Spain) on a rainfed Vertisol within the wheat-chickpea and wheat-faba bean rotation framework of a long-term experiment started in 1986. The aim was to determine the effect of tillage systems [no tillage (NT) and conventional tillage (CT)] on chickpea and faba bean N2 fixation. Fixation was calculated using the 15N isotopic dilution (ID) and 15N natural abundance (NA) methods with the reference being the wheat crop. The strong inter-annual rain variation caused great differences in the behaviour of both leguminous plants with regard to grain yield, nodule biomass and N2 fixation. The NT system showed more nodule biomass than the CT system in both legumes. The ID method was more accurate than the NA method in determining N2 fixation. The average amount of fixed N in faba bean (80 kg ha?1 year?1) was much greater than that in chickpea (31 kg ha?1 year?1). The Vertisol under the NT system offered more favourable conditions for the stimulation of the N2 fixation, with fixed N values that were significantly higher than under CT. The N added to the system through N2 fixation was low in faba bean and virtually nonexistent in chickpea, only in terms of above-ground biomass.  相似文献   

13.
扩繁条件对3种丛枝菌根真菌(AMF)的影响   总被引：1，自引：0，他引：1  
为了提高AM真菌的培养效率,降低培养成本,采用温室盆栽法,以玉米和红三叶草为宿主,以摩西球囊霉(Glomus intraradices,G.i)、根内球囊霉(Glomus mosseae,G.m)地表球囊霉(Glomus versiforme,G.v) 3种AM真菌为供试菌种,在以河砂、草炭、珍珠岩、蛭石和泥炭不同配比组成的3种基质中进行培养,并设置2个营养液浓度梯度（无营养液;10%浓度霍氏营养液）,进行3×2因子交叉实验,通过测定侵染率、孢子密度以及宿主的光合特性,从而筛选出各菌种最优的轻型基质配方及其相应的营养液浓度。结果表明,P2（蛭石:草炭:河砂=4:1:1）配方是G.m和G.i良好的扩繁基质,P3（珍珠岩:蛭石:草炭:河砂=2:2:1:1）配方是最适合G.v的扩繁基质,在对菌种的侵染率、产孢量以及宿主植物的光合效率的提高等方面优于其他配方。与以往研究结果不同的是,本研究中的3个基质配方,施加营养液的处理都明显降低了3种AM真菌的孢子数,降幅分别为43.51%~96.26%、57.50%~99.39%、27.79%~92.56%;且每个菌种的侵染率也不同程度地降低,其机理有待于进一步研究。  相似文献   

14.
Earthen pot experiments were conducted in a randomized block design with three replications to evaluate the effects of sesame varieties, DS 1 and E 8 on a single inoculation of Glomus fasciculatum (Thax. sensu Gerd.) Gerd. and Trappe and Acaulospora laevis Gerd. & Trappe respectively, dual inoculation of arbuscular mycorrhizal fungi (AMF) with Azotobacter chroococcum (Ac) or Pseudomonas fluorescens (Pf) and a triple inoculation of AMF, A. chroococcum and P.  fluorescens. The results revealed that inoculation of AMF + Ac + Pf to DS 1 and E 8 varieties stimulated increased AMF colonization, plant growth, i.e. shoot, root length, fresh and dry weight of shoot and root, phosphorus uptake and number of capsules significantly over the dual and single inoculation treatments. The association of bacteria and AMF provides evidence that bacteria are involved in the beneficial effects to AMF on sesame varieties.  相似文献   

15.
Growth, dry matter partitioning between shoots and roots, and extent of nodulation were characterised in four novel self-fertile highly inbred lines (referred to as A, B, C and D) of white clover (Trifolium repens L.) thought to differ fundamentally in their nitrogen relations and therefore regarded as candidate material for genetic mapping. Plants were inoculated with a mixture of three strains of Rhizobium and grown in flowing nutrient solutions without N for 18 d. Half the plants were then supplied with 20 μM NO3 - during a 36 d treatment period, the remaining plants acting as ‘controls’ solely dependent upon N2 fixation for acquisition of N. Total dry matter production and shoot:root ratios were similar in all lines supplied with NO3 - and in control plants of lines B and C. Growth was severely reduced in control plants of line D and to a lesser extent in control line A. These effects were attributed to a failure to develop effective N2 fixation capacity after apparently normal infection. Mean nodule size, nodule numbers and nodule d.w. per plant were extremely low in line D compared with the other lines, irrespective of whether NO3 - was supplied. Lines A, B and C differed in the severity with which NO3 - decreased mean d.w. per nodule and total nodule d.w. per plant relative to corresponding control plants, with line C being least sensitive. Nitrate also decreased the total number of nodules per plant relative to control plants after day 14 in all lines except C, and most severely in line B. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

16.
Studies on N2 fixation by grain legumes during periods of winter waterlogging prone Mediterranean regions have rarely been performed across scales. Here, we quantified the spatial variability of N2 fixation by rain‐fed chickpea (Cicer arietinum L.) at the field‐ and micro‐scales (0.15 m spacing) after waterlogging during the vegetative growth phase in the winter. We also determined effects of tillage (standard and minimum) and crop and soil variables on N2 fixation in water stressed conditions. After waterlogging, yield was greatly reduced but there were no visible signs of water stress or tillage effects on N2 fixation. At the field scale, percent N derived from N2 fixation (%Ndfa) ranged from 51 to 93 % and was related to the amount of soil‐derived N in the plant. Total grain N did not increase when N2 fixation increased and the amount of N derived from the soil was replaced with fixed N. In contrast, %Ndfa at the micro‐scale, ranging between 0 to 72 %, was primarily related to yield and total plant N whereas available soil N or any of the other measured soil properties were not significant predictors of %Ndfa. Total N in the grain increased solely due to N2 fixation as the contribution from soil N remained constant. Although %Ndfa had a nearly pure nugget variance across the scales, total N derived from N2 fixation (gNdfa) showed a relatively high level of spatial correlation. The range of available soil N pools was likely different at the two scales, leading to differences in the responses of chickpea N2 fixation to available soil N.  相似文献   

17.
The response to N fertilization of a short-duration pigeonpea genotype, ICPL 87, was studied in the field to assess the scope for genetically improving symbiotic N2 fixation by pigeonpea. The field study was undertaken during 1985, 1986 and 1987 growing seasons on Vertisol and Alfisol at ICRISAT Center (peninsular India), Inceptisol at Gwalior (central India) and Entisol at Hisar (northern India) in as non-limiting environmental conditions as possible. Nitrogen fertilizer was applied to the soil at various growth stages to determine when N becomes most limiting. There was a significant response in grain yield to fertilizer N applied at flowering in Vertisol but not in Alfisol, Inceptisol or Entisol. This suggests that biological N2 fixation by short-duration pigeonpea was not adequate to meet N requirements of the crop grown in Vertisol but that it was probably adequate in the other three soil types. These results are discussed in relation to the nodulation and acetylene reductase activity of pigeonpea and also N mineralization potential of different soils. It can be concluded that there is a need for genetic improvement of N2 fixing ability of short-duration pigeonpea grown on heavy textured soils such as Vertisols.  相似文献   

18.
Some fungal species have been shown to improve plant growth under drought conditions and to increase plant phosphorus (P) uptake from the soil. How moisture limitation, P availability and fungal inoculation interact to affect plant physiology and growth is, however, poorly understood. Here, we studied the combined effects of fungal (arbuscular mycorrhizal fungi (AMF) or Penicillium spp.) inoculations and phosphorus (P) fertilization (0, 45 and 90 kg ha?1) on the net rate of photosynthesis, water‐use efficiency, P uptake and growth of spring wheat (Triticum aestivum var. Superb) under field conditions at two locations (Castor and Vegreville) in Alberta, Canada. Both fungal inoculation and P application increased the rate of photosynthesis. Under the same P level, AMF inoculation had a greater positive effect on the rate of photosynthesis than Penicillium inoculation. The AMF inoculation increased the instantaneous water‐use efficiency (WUEi) of plants at Castor, but not at Vegreville. Leaf carbon isotope discrimination (CID, Δ13C) increased with the rate of P application but was not affected by fungal inoculations. Phosphorus concentrations of stem and seed increased with both fungal inoculation and P application irrespective of location, with AMF inoculation showing the largest effects. The interaction between P addition and fungal inoculation was significant for stem P concentration in Vegreville. Both fungal inoculation and P application increased the leaf area index (LAI), biomass production and grain yield at both locations. Under the same P level, AMF inoculation had a greater positive effect on LAI, biomass production and grain yields than Penicillium inoculation. Morphological characters such as spike length and kernels/spike were also improved by fungal inoculation and P application at both locations. We conclude that the studied sites were deficient in P availability, and both fungal inoculation and P application improved P uptake and crop productivity, while the effect of fungal inoculation on water‐use efficiency was site specific.  相似文献   

19.
Soybean is a special crop that can utilize N2 in the air via symbioses with Rhizobium spp. The formation of effective nodules is a complex process in which nodulation outer proteins (Nops) are determinants of establishment of a symbiotic relationship. We constructed a Sinorhizobium fredii HH103ΩnopB mutant. A nodulation test showed that the mutant had a negative effect on the Suinong14, ZYD00006, Dongnong594 and Charleston soybean lines. Recombinant inbred soybean lines were independently inoculated with the mutant and wild‐type strains, and five and four quantitative trait loci (QTLs) were identified by analysing the nodule number (NN) and nodule dry weight (NDW), respectively. We chose one QTL that overlapped with other studies and a novel QTL identified in our study and selected six candidate genes for further analysis. The qRT‐PCR analysis showed that only changes in Glyma.17G166200 expression depended on NopB. Further analysis showed that Glyma.17G166200 encoded a protein with a D‐glucose‐binding domain and a serine‐threonine/tyrosine protein kinase catalytic domain that was involved in the abscisic acid (ABA) pathway.  相似文献   

20.
Estimates of N2 fixation in segregating populations of bean plants based on 15N-isotope methods are technically demanding and expensive; therefore, indirect measures based on related traits including total seed N were used to select for improved N2 fixation and yield. In 1985, six populations of F2-derived F3 families resulting from six parental lines crossed to a common tester were grown in field trials on a low-N soil. In 1986, 25 selected half-sib families and two populations of full-sib F4 families were grown under similar conditions. Parents and a non-nodulating soybean line were included both years. Narrow sense (HNS) heritability estimates based on parent-offspring regressions ranged from 0.57 for total seed N to 0.39 for shoot biomass in one population, but were near zero for all measured traits in a second population. Among the criteria used to identify parental lines with superior potential for producing progenies with high total seed N, testcross population means combined with estimates of realized heritability were the most reliable. Selection of the best F3 families for total seed N resulted in F4 families with increased total seed N and higher seed yields, while seed protein percentage was unchanged. When plants are grown on low-N soils, selection for total seed N offers a useful alternative to selection for increased N2 fixation based on 15N-isotopic or total-N-difference method.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号