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1.
The exploitation of minerals from coastal dunes in northeastern Brazil requires subsequent revegetation for ecosystem recovery. In mined dunes areas, we have compared the growth of Guazuma ulmifolia and Tabebuia roseo-alba seedlings using substrates containing 10 or 15% of cattle manure, uninoculated or inoculated with a mixture of native arbuscular mycorrhizal fungi (AMF) or exotic AMF (Acaulospora longula). The inoculated plants had a higher percentage of colonization than those that were uninoculated. Plants of G. ulmifolia had the highest growth when inoculated with native AMF and fertilized with 10% manure or inoculated with A. longula and fertilized with 15% manure. In general, fertilization with 15% manure did not produce greater seedling development and had a negative effect on the effectiveness of the symbiosis. Twenty one AMF species were recorded in the planting areas at the end of the experiments, with a predominance of species that form acaulosporoid spores in areas with T. roseo-alba and gigasporoid spores in areas with G. ulmifolia plants. The incorporation of 10% cattle manure and native AMF in the substrate of T. roseo-alba and G. ulmifolia seedlings contributes to the initial establishment of plants in the field and to the incorporation of AMF propagules in the soil of the revegetated mined dunes.  相似文献   

2.
The mycorrhizal enhancement of plant growth is generally attributed to increased nutrients uptake. A greenhouse experiment was conducted to investigate the effect of arbuscular mycorrhizal fungi (AMF) inoculation on the growth and nutrient uptake of directly seeded wetland rice. Seeds were germinated and inoculated with arbuscular mycorrhizal fungi or left uninoculated. The plants were grown at 60% of ‐0.03 MPa to establish the mycorrhizas. After 5 weeks, half of the pots were harvested and the rest were flooded with deionized water to maintain 3–5 cm of standing water until harvesting (122 days after sowing). Mycorrhizal fungal colonization of rice roots was 36.2% at harvest. Mycorrhizal fungi inoculated rice seedlings grew better compared to uninoculated seedlings and had increased grain yield (10%) at the harvesting stage. Shoot and root growth were effectively increased by AMF inoculation at the harvesting stage. The nitrogen (N) and phosphorus (P) acquisition of direct seeding wetland rice were significantly increased by AMF inoculation. The AMF enhanced N and P translocation through the hyphae from soils to roots/shoots to grains effectively.  相似文献   

3.
《Journal of plant nutrition》2013,36(8):1311-1323
Tomato (Lycopersicon esculentum Mill.) yields are known to decrease for plants grown in saline soils. This study was conducted to determine the effects of arbuscular mycorrhizal fungi (AMF) inoculation on fruit yield and mineral content of salt-tolerant and salt-sensitive tomato cultivars grown with varied levels of salt. NaCl and CaCl2were added to soil in the irrigation water in equal molar ratios to give ECe values of 1.4 (nonstressed) and 4.9 dS m?1 (salt stressed). Plants were grown in a greenhouse using unsterilized, low phosphorus (P) (silty clay) soil-sand mix. Mycorrhizal root colonization occurred whether cultivars were salt stressed or nonstressed, but the extent of AMF root colonization was higher in AMF inoculated than uninoculated plants. The salt tolerant cultivar ‘Pello’ generally had higher AMF root colonization than the salt sensitive cultivar ‘Marriha’. Shoot dry matter (DM) yield, fruit fresh yield, and AMF colonization were higher for plants grown under nonstressed than for plants grown under salt stressed conditions. Shoot DM and fruit fresh yields were higher in AMF inoculated than uninoculated plants grown with or without salt stress. Pello generally had higher fruit fresh yield per plant and fruit weight than Marriha, but these differences were only significant for fruit weight in unioculated plants grown under salt stressed conditions. The enhancement in fruit fresh yield due to AMF inoculation was 26 and 23% under nonstressed and 28 and 46% under salt stressed treatments for Pello and Marriha, respectively. For both cultivars, fruit contents of P, potassium (K), zinc (Zn), copper (Cu), and iron (Fe) were higher in AMF inoculated compared with uninoculated plants grown under nonstressed and salt stressed conditions. Fruit Na concentrations were lower in AMF inoculated than uninoculated plants grown under salt stressed conditions. The enhancement in P, K, Zn, Cu, and Fe acquisition due to AMF inoculation was more pronounced in Marriha than in Pello cultivar under salt stressed conditions. The results of this study indicated that AMF inoculated plants had greater tolerance to salt stress than unioculated plants.  相似文献   

4.
丛枝菌根对酸枣实生苗耐盐性的影响   总被引：15，自引：4，他引：15       下载免费PDF全文
本文研究了在土中加入不同量NaCl条件下 (0、1 5、3 0、4 5gkg-1干土 )接种丛枝菌根真菌 (AMF)Glomusmosseae对盆栽酸枣 (ZizyphusspinosusHu)实生苗生长及耐盐性的影响。结果表明 ,无论接种与否 ,植株的高度、根茎叶的干鲜重均随土壤NaCl浓度的增加而降低 ,而根、茎、叶和整株的Na浓度及Na全量均随土壤NaCl浓度的增加而增大。在土壤盐浓度相同的条件下 ,接种AMF植株的生长量 (株高、鲜重、干重等 )和叶片的叶绿素含量显著高于不接种植株。接种AMF的植株茎、叶中Na浓度低于不接种植株 ,而根中Na浓度、植株Na总量显著高于不接种植株。盐浓度最大的接种处理 ,其植株生长量和叶片叶绿素含量均高于不加盐不接菌处理。播种时进行盐胁迫处理和播种后 4 0d开始进行盐胁迫处理对菌根的侵染率、植株生长的影响差异不显著。上述四种盐浓度播种时进行盐处理的接种AMF植株的总干重比不接种植株分别提高 16 4 %、14 9%、4 8%、35 % ,在播种后 4 0d进行盐处理的接种AMF的植株比不接种植株分别提高 194 %、12 7%、72 %、4 6 %。结果证明 ,酸枣实生苗具有较强的耐盐性 ,其生长对菌根真菌有很强的依赖性 ,接种菌根真菌提高了其耐盐能力。  相似文献   

5.
In sustainable agriculture, arbuscular mycorrhizal (AM) fungal inoculation in agronomical management might be very important, especially when the efficiency of native inocula is poor. Here, we assessed the effect of native and exotic selected AM fungal inocula on plant growth and nutrient uptake in a low input Trifolium alexandrinum-Zea mays crop rotation. We evaluated the effects of four exotic AM fungal isolates on T. alexandrinum physiological traits in greenhouse. Then, the field performances of T. alexandrinum inoculated with the exotic AMF, both single and mixed, were compared to those obtained with a native inoculum, using a multivariate analysis approach. Finally, we tested the residual effect of AM fungal field inoculation on maize as following crop. Multivariate analysis showed that the field AM fungal inoculation increased T. alexandrinum and Z. mays productivity and quality and that the native inoculum was as effective as, or more effective than, exotic AM fungal isolates. Moreover, the beneficial effects of AMF were persistent until the second year after inoculation. The use of native AMF, produced on farm with mycotrophic plants species, may represent a convenient alternative to commercial AM fungal inocula, and may offer economically and ecologically important advantages in sustainable or organic cropping systems.  相似文献   

6.
Two microcosm experiments were conducted to study the role of extraradical mycelium (ERM) of arbuscular mycorrhizal fungi (AMF) in establishment and growth of tree species used for revegetation in anthropogenic substrates. Inoculated or non-inoculated Acer pseudoplatanus, Alnus glutinosa or Salix purpurea seedlings were grown with Calamagrostis epigejos (a grass spontaneously colonising degraded ecosystems) in two substrates (fly ash and coal mine spoil) either in direct root contact or in rhizoboxes with interaction only via ERM network. In both experiments, inoculation with AMF mostly had a positive effect on the growth of trees and increased the aggregation of fly ash. When plants grew in direct root-to-root contact, grass presence negatively affected tree growth, but it significantly improved mycorrhizal development (colonization of tree seedlings, spore number and ERM length). When grass and tree roots interacted via the ERM network, tree seedlings were successfully colonised by the ERM spreading from the C. epigejos roots. Mechanical disturbance of the ERM links between plants reduced AMF development and tree height in both substrates, but tree shoot biomass was not affected. In fly ash, inoculated, non-disturbed treatments showed significant transfer of 32P from the grass to the tree seedlings. It can be concluded that roots of A. pseudoplatanus, A. glutinosa or S. purpurea seedlings can be colonised from the ERM network radiating from quickly growing grasses, which can act as important agents for AMF distribution and facilitate mycorrhization of planted trees. In particular for willow, grass seems to be an essential nurse plant to achieve successful root colonisation.  相似文献   

7.
Lonicera confusa, a traditional Chinese medicine herb for treating cold, flu, acute fever, and so forth, is often grown artificially in acidic soils and suffers from phosphorus (P) deficiency. A five-year field experiment was carried out to study the colonization rate, growth, nutrition, and chlorogenic acid content of Lonicera confusa seedlings inoculated with arbuscular mycorrhizal (AM) fungi, Glomus etunicatum and Glomus intraradices. Before transplanting into a field, both AM-inoculated and uninoculated control plants were cultured in nursery beds. In the plants inoculated with the AM fungi, the colonization rate decreased linearly with time and a greater decrease was observed in the plants inoculated with G. intraradices than with G. etunicatum, while the AM colonization increased from 0% to 12.1% in the uninoculated control plants 5 years after transplanting. Plant height, crown diameter, number of new branches, and flower yield increased significantly by AM inoculation as compared to the uninoculated control. Phosphorus concentrations in leaves and flowers increased, and plant uptake of nutrients, e.g., nitrogen (N), P, and potassium (K), was also enhanced significantly by AM inoculation. The Lonicera confusa seedlings had a better response to inoculation of G. intraradices than G. etunicatum in both growth and chlorogenic acid content in flowers. In contrast, both plant P uptake and P concentrations in leaves and flowers were similar between two fungal inoculations. The positive responses of Lonicera confusa to AM inoculation in growth, nutrient uptake, flowering, and chlorogenic acid content in flowers suggested that AM inoculation in nursery beds could promote the plant growth and increase chlorogenic acid content in flowers of Lonicera confusa when grown on acidic and P-deficient soils.  相似文献   

8.
The effects of an arbuscular mycorrhizal fungus (AMF) (Glomus constrictum Trappe) on the growth and some physio-biochemical indexes of Zea mays L. seedlings under different levels of diesel stress were investigated in a pot study. Generally, the symbiotic relationship between corn and AMF can be well established under diesel stress. This was reflected by the better physio-biochemical index of the plants inoculated with G. constrictum whose colonization rates were between 47.30% and 91.50%. Compared with the non-inoculated ones, the heights and basal diameters of the inoculated seedlings increased by 0.08-47.20% and 6.74-35.71% respectively. The relative contents of chlorophyll and soluble proteins increased by 1.88-38.79% and 3.87-77.27% respectively, while the contents of malondialdehyde and free proline decreased by 2.74-52.74% and 24.69-32.86%. Three antioxidant enzymes reacted differently under the diesel stress. The activities of superoxide dismutase (SOD) and catalase (CAT) increased at low diesel concentration, but decreased at high concentration. In contrast, peroxidase (POD) had a decreased activity at low diesel concentration, but an increased activity at high concentration. On the whole, the activity of three antioxidant enzymes in the plants inoculated with AMF were higher than those without AMF inoculation. Our results support the view that antioxidant enzymes have great influence on the biomass of plants, and AMF can improve the capability of scavenging the reactive oxygen and alleviate Z. mays seedlings from diesel stress.  相似文献   

9.
Macrophomina phaseolina. the cause of damping-off and charcoal root rot disease on slash pine seedlings (Pinus elliottii Engelm var. elliottii), was antagonized by an unidentified basidiomycete species under laboratory and nursery conditions. Aseptically-grown slash pine seedlings died 3 days after inoculation with M. phaseolina, whereas seedlings inoculated with the basidiomycete sp., or basidiomycete sp. plus M. phaseolina, and uninoculated controls were alive after 6 months. In nursery studies, survival of slash pine seedlings in plots inoculated with M. phaseolina was significantly lower (57 per cent) than survival resulting from inoculations with the basidiomycete sp. (90 per cent), or basidiomycete sp. plus M. phaseolina (84 per cent), and the uninoculated controls (81 per cent). Electron microscopy showed that the basidiomycete sp. is a hyperparasite on mycelia of M. phaseolina. Preliminary evidence indicates that the hyperparasite is not host-specific but will infect other fungal pathogens. Two ectomycorrhizal fungi were not parasitized by the basidiomycete.  相似文献   

10.
Arbuscular mycorrhizal fungi (AMF) have the capability to improve crop yields by increasing plant nutrient supply. A pot experiment was conducted under natural conditions to determine the response of AMF inoculation on the growth of maize (Zea mays L.), sorghum (Sorghum bicolor L.), millet (Pennisetum glaucum L.), mash bean (Vigna mungo L.), and mung bean (Vigna radiata. L.) crops during 2008. The experiment was conducted as a completely randomized design in three replications using phosphorus (P)–deficient soil. Three plants were grown in 10 kg soil up to the stage of maximum growth for 70 days. Spores of AMF were isolated from rhizosphere of freshly growing wheat and berseem crops and mixed with sterilized soil with fine particles. Crops were inoculated in the presence of indigenous mycorrhiza with the inoculum containing 20 g sterilized soil mixed with 40–50 AMF spores. Inoculation with AMF improved yield and nutrient uptake by different crops significantly over uninoculated crops. Inoculated millet crop showed 20% increase in shoot dry matter and 21% in root dry matter when compared with other inoculated crops. Increases of 67% in plant nitrogen (N) and iron (Fe) were observed in millet, 166% in plant P uptake was observed in mash beans, 186% in zinc (Zn) was measured in maize, and 208% in copper (Cu) and 48% in manganese (Mn) were noted in sorghum crops. Maximum root infection intensity of 35% by AMF and their soil spore density were observed in millet crop followed by 32% in mash beans. Results suggest that inoculation of AMF may play a role in improving crop production and the varied response of different crops to fungi signifies the importance of evaluating the compatibility of the fungi and plant host species.  相似文献   

11.
Earthworms and arbuscular mycorrhizal fungi (AMF) are important macrofauna and microorganisms of the rhizosphere. The effect of the inoculation of soil with earthworms (Aporrectodea trapezoides) and mycorrhiza (Rhizophagus intraradices) on the community structure of mycorrhizal fungi and plant nutrient uptake was determined with split plots in a maize field. Maize plants were inoculated or not inoculated with AMF, each treated with or without earthworms. Wheat straw was added as a feed source for earthworms. Inoculating AMF significantly increased maize yield (p?<?0.05), and the yield was further enhanced by the addition of earthworms. Alkaline phosphomonoesterase activities, soil microbial biomass carbon (SMBC) and nitrogen (SMBN) increased with the addition of both earthworms and AMF. Soil inorganic N and available K were positively affected by earthworms, while available P showed a negative relationship with AMF. Treatment with both AMF and earthworms increased shoot and root biomass as well as their N and P uptake by affecting soil phosphomonoesterase and urease activities, SMBC, SMBN, and the content of available nutrients in soil. The applied fungal inoculants were successfully traced by polymerase chain reaction with novel primers (AML1 and AML2) which target the small subunit rRNA gene. The amplicons were classified by restriction fragment length polymorphism and sequencing. Moreover, field inoculation with inocula of non-native isolates of R. intraradices appeared to have stimulated root colonization and yield of maize. Adding earthworms might influence native AMF community, and the corresponding abundance increased after earthworms were inoculated, which has positive effects on maize growth.  相似文献   

12.
Abstract

In two pot experiments, cucumber (Cucumis sativus L. cv. Jinlu No. 3) seedlings were each inoculated with one of three arbuscular mycorrhizal fungi (AMF), Glomus mosseae, Glomus intraradices, or Glomus versiforme, or uninoculated. Seedling growth and weight of single fruit were investigated. The results indicated that growth of seedlings was significantly enhanced by G. mosseae, inhibited by G. versiforme, and not significantly influenced by G. intraradices. The dry weight of seedlings inoculated with G. mosseae was 1.2 times its counterparts. The concentrations of nitrogen (N) and phosphorus (P) in roots and magnesium (Mg), copper (Cu), and zinc (Zn) concentration in shoots were increased by inoculating the three AMF, and potassium (K) and iron (Fe) concentrations in shoots decreased significantly. The weights of single fruit of plants preinoculated with G. mosseae and G. versiforme were about 1.4 and 1.3 times higher than those from the uninoculated treatment, respectively.  相似文献   

13.
This study focused on the application of native strains of arbuscular mycorrhizal fungi (AMF) and Sinorhizobium in effective crop production during reclamation of coal‐mine spoil banks. Two greenhouse experiments were conducted in spoil‐bank clay with a low dose of organic amendment to determine whether the microbial inoculation improves growth and utility qualities of two cultivars of Linum usitatissimum L. (oil and fiber flax). Inoculation with two native AMF isolates (Glomus mosseae, G. intraradices, and their mixture) significantly increased growth and shoot phosphorus (P) concentration of both flax cultivars. Inoculated fiber flax plants produced fivefold more fibers than the uninoculated ones. In oil flax, mycorrhizal inoculation significantly but quantitatively to a minor degree decreased the concentration of nonsaturated fatty acids in the seed oil. A mixture of five native Sinorhizobium sp. strains supported growth and P uptake of oil flax only in the absence of AMF. However, these beneficial effects of the bacteria were significantly lower as compared to AMF. No synergic action of Sinorhizobium strains and AMF was observed, and their interactions were often even antagonistic. Inoculation with AMF significantly decreased population density of Sinorhizobium in the soil. These results suggest that a careful selection of suitable bacterial strains is necessary to provide effective AMF combinations and maximize flax‐growth support.  相似文献   

14.
  目的  绿肥作为生物肥料,加入土壤后如何提高植物对绿肥利用效率及氮转化效率一直是热点研究课题。本文使用新鲜苜蓿（Medicago sativa）作为绿肥,接种丛枝菌根真菌（Arbuscular Mycorrhizal Fungi,AMF）和深色有隔内生真菌（Dark Septate Endophytes,DSE）,探究利用微生物接种提高植物对绿肥利用效率和促进氮素转化的方法。  方法  本研究在温室条件下,采用玉米（Zea mays L.）作为供试植物,使用新鲜苜蓿（Medicago sativa）作为绿肥,并接种AMF和DSE。试验设置4个处理:绿肥（L）;绿肥 + AMF（L + A）;绿肥 + DSE（L + D）;绿肥 + DSE + AMF（L + D + A）。  结果  AMF和DSE可以同时定殖玉米植株;接种真菌处理均显著提高玉米株高与生物量,其中L + D处理效果最好,株高与干重的值分别为86.25 cm、41.893 g每盆。L + D处理较其它接菌处理对植物全氮、绿肥的利用效率促进作用最为显著,最大值分别为585.27 mg、76.50%,且L + D处理下土壤硝氮、铵氮含量、脲酶活性最高,分别为0.201 g kg?1、0.339 g kg?1以及81.51 μg kg 24 h?1。接种AMF处理土壤全氮含量均显著高于其不接种AMF处理,同时接种AMF和DSE对玉米生长产生一定程度抑制作用。  结论  绿肥接种深色有隔内生真菌在植物生物量及营养利用等方面略好于接种丛枝菌根真菌,而双接菌处理需进一步研究证明协同或竞争关系。该结果为利用微生物技术提高绿肥在土壤中的利用效率及促进氮素的转化提供理论依据。  相似文献   

15.
The composition of arbuscular mycorrhizal fungi (AMF) communities found in agricultural systems has been found to be very different to that of forest. The implications of this, if any, for the restoration of indigenous forest on ex-agricultural land is poorly understood. This study investigated the effect that AMF communities isolated from ex-agricultural and forest soils have on the growth of an indigenous New Zealand tree species (Podocarpus cunninghamii). The forest AMF community was isolated from a remnant stand of P. cunninghamii forest and the ex-agricultural AMF from a retired grazing grassland. In addition, the study examined how the two AMF communities affected the competitiveness of P. cunninghamii when grown in competition with an invasive grass species (Agrostis capillaris), which is frequently dominant on ex-agricultural land in New Zealand. P. cunninghamii growth was significantly decreased by inoculation with ex-agricultural AMF compared to forest AMF. Furthermore, the forest AMF community was able to significantly increase P. cunninghamii root production when in competition with A. capillaris. The findings suggest that when attempting to restore indigenous forest on ex-agricultural land, inoculation of tree seedlings with appropriate forest AMF may improve their growth and survival.  相似文献   

16.
Chile's seedling production industry has been growing for the last 10 years, and demand has actually reached 1250 million seedlings per year. This system has special relevance due to the high cost of seeds. In addition, there is an increasing demand for substituting synthetic agrochemicals. Therefore, the potential use of plant growth-promoting rhizobacteria (PGPR) in tomato production has been investigated. Before sowing, the micro-organisms provided by Biogram S.A. were inoculated into the substrate diluted in 250 mL/L unchlorinated water. The experiment was laid out in a ‘split-plot’ design with the two plant substrates as main plots and the inoculants as subplots, including six replicates per treatment. Tomato seedlings were grown using two different plant substrates: a mixture of 70% peat and 30% perlite by volume, and a substrate with 20% peat, 20% perlite and 60% compost by volume, both inoculated with Bacillus subtilis or Pseudomonas fluorescens or Bioroot®, which is a commercial product containing B. subtilis, P. fluorescens, Trichoderma harzianum, yeast, algae and Nocardia. For control, uninoculated tomato seedlings were grown on the respective plant substrates. Variance analysis did not identify significant interactions between substrate type (main plots) and inoculation treatment (subplots), P ≤ 0.05. There were significant differences between inoculants (P ≤ 0.05). Means were compared by using the Tukey's multiple range test. Tomato growth in terms of leaf area (cm2/plant) and shoot and root dry weight (g/10 plants) was improved for the seedlings grown on the substrate with 70% peat and 30% perlite, compared to the compost containing an alternative that is valid for both uninoculated perlite peat and all inoculated treatments where perlite peat was outstanding. Inoculation with Bioroot® improved the leaf area, shoot dry weight, root dry weight, radical contact area, volume of roots and root forks compared with the control without inoculation, when both plant substrates were analysed together. Thus, inoculation with Bioroot® can be recommended as an alternative to tomato seedling growers' dependence on synthetic agrochemicals.  相似文献   

17.
This study evaluated the interactive effect of arbuscular mycorrhizal fungi (AMF) inoculation and exogenous phosphorus supply on soil phosphotases, plant growth, and nutrient uptake of Kandelia obovata (Sheue, Liu & Yong). We aimed to explore the ecophysiological function of AMF in mangrove wetland ecosystems, and to clarify the possible survival mechanism of mangrove species against nutrient deficiency. K. obovata seedlings with or without AMF inoculation (mixed mangrove AMF), were cultivated for six months in autoclaved sediment medium which was supplemented with KH2PO4 (0, 15, 30, 60, 120 mg kg−1). Then the plant growth, nitrogen and phosphorus content, root vitality, AMF colonization and soil phosphatase activity were analyzed. The inoculated AMF successfully infected K. obovata roots, developed intercellular hyphae, arbuscular (Arum-type), and vesicle structures. Arbuscular mycorrhizal fungi colonization ranged from 9.04 to 24.48%, with the highest value observed under 30 and 60 mg kg−1 P treatments. Soil P supply, in the form of KH2PO4, significantly promoted the height and biomass of K. obovata, enhanced root vitality and P uptake, while partially inhibiting soil acid (ACP) and alkaline phosphotase (ALP) activities. Without enhancing plant height, the biomass, root vitality and P uptake were further increased when inoculated with AMF, and the reduction on ACP and ALP activities were alleviated. Phosphorus supply resulted in the decrease of leaf N–P ratio in K. obovata, and AMF inoculation strengthened the reduction, thus alleviating P limitation in plant growth. Arbuscular mycorrhizal fungi inoculation and adequate P supply (30 mg kg−1 KH2PO4) enhanced root vitality, maintained soil ACP and ALP activities, increased plant N and P uptake, and resulted in greater biomass of K. obovata. Mutualistic symbiosis with AMF could explain the survival strategies of mangrove plants under a stressed environment (waterlogging and nutrient limitation) from a new perspective.  相似文献   

18.
Salt stress has become a major menace to plant growth and productivity. The main goal of this study was to investigate the effect of inoculation with the arbuscular mycorrhizal fungi (AMF; Rhizophagus intraradices) in combination or not with plant growth‐promoting rhizobacteria (PGPR; Pseudomonas sp. (Ps) and Bacillus subtilis) on the establishment and growth of Sulla coronaria plants under saline conditions. Pot experiments were conducted in a greenhouse and S. coronaria seedlings were stressed with NaCl (100 mM) for 4 weeks. Plant biomass, mineral nutrition of shoots and activities of rhizosphere soil enzymes were assessed. Salt stress significantly reduced plant growth while increasing sodium accumulation and electrolyte leakage from leaves. However, inoculation with AMF, whether alone or combined with the PGPR Pseudomonas sp. alleviated the salt‐induced reduction of dry weight. Inoculation with only AMF increased shoot nutrient concentrations resulting in higher K+: Na+, Ca2+: Na+, and Ca2+: Mg2+ ratios compared to the non‐inoculated plants under saline conditions. The co‐inoculation with AMF and Pseudomonas sp. under saline conditions lowered shoot sodium accumulation, electrolyte leakage and malondialdehyde (MDA) levels compared to non‐inoculated plants and plants inoculated only with AMF. The findings strongly suggest that inoculation with AMF alone or co‐inoculation with AMF and Pseudomonas sp. can alleviate salt stress of plants likely through mitigation of NaCl‐induced ionic imbalance, thereby improving the nutrient profile.  相似文献   

19.
《Applied soil ecology》2003,22(2):103-111
The re-establishment of native shrub species in the Mediterranean basin serves to restore the characteristic biodiversity and to prevent the processes of erosion and desertification in semiarid areas. A field experiment was carried out in an abandoned semiarid agricultural Mediterranean area to assess the effectiveness of mycorrhizal inoculation, with a mixture of native arbuscular mycorrhizal (AM) fungi or an allochthonous AM fungus (Glomus claroideum), on the establishment of Olea europaea subsp. sylvestris L., Pistacia lentiscus L., Retama sphaerocarpa (L.) Boissier and Rhamnus lycioides L. seedlings in this area. One year after planting, shoot biomass of inoculated O. europaea and P. lentiscus seedlings was greater, by about 630% and 300%, respectively, than that of non-inoculated plants. Shoot biomass of G. claroideum-colonised R. sphaerocarpa plants was significantly greater than that of seedlings inoculated with the mixed native AM fungi after 12 months. The increase of R. lycioides growth due to inoculation with native AM fungi was significantly greater than that of G. claroideum-colonised seedlings during the same growth period. Inoculation with a mix of native AM fungi was the most effective treatment for increasing shoot biomass and N, P and K contents in shoot tissues of R. lycioides seedlings. The mixture of native AM fungi was the most effective with respect to colonisation of the roots of O. europaea and R. lycioides, but the native AM fungi and G. claroideum achieved similar levels of colonisation in P. lentiscus and R. sphaerocarpa. The use of native mycorrhizal potential as a source of AM inoculum may be considered a preferential inoculation strategy to guarantee the successful re-establishment of native shrub species in a semiarid degraded soil.  相似文献   

20.
The role of cobalt in the processes leading to nodule initiation in Lupinus angustifolius L. cv. Uniharvest was studied. Survival and multiplication of Rhizobium lupini were examined in Lancelin soil and in the rhizosphere of L. angustifolius grown in it, with or without inoculation with antibiotic-resistant derivatives of R. lupini strain WU425. A clearing and staining technique was then used to record the incidence of nodule initiation in L. angustifolius seedlings.Within the constraints of experimental techniques, soil and rhizosphere numbers of R. lupini were unaffected by the cobalt status of the soil. Cobalt limitation was, however, inhibitory to nodule initiation in L. angustifolius, with reductions of up to 13 and 30% in nodule initiation for inoculated and uninoculated seedlings respectively.The severity of cobalt deficiency in L. angustifolius seems to be due solely to the plant's inability to provide cobalt to the rhizobia within the plant and not to any external limitation on their growth in soil or rhizosphere.  相似文献   

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