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1.
The aim of this experiment was to evaluate the impact of colonization with arbuscular mycorrhizal (AM) fungus Glomus constrictum on the biomass production, flower quality, chlorophyll content, macronutrients and heavy metals content of marigold (Tagetes erecta L.) planted under uncontaminated soil and watered with various rates of sewage water. Sewage water utilization significantly decreased biomass production, characters of flower, nutrient concentration and rates of mycorrhizal colonization of mycorrhizal (M) and non-mycorrhizal (NM) marigold as compared to control untreated plants especially at the higher rates, but the reduction rate was proportionally higher in non-AM treatments. Mycorrhizal plants had significantly greater yield, relative chlorophyll content, leaf area, flower quality and element (P, N, K and Mg) content compared to non-inoculated marigold plants irrigated with or without sewage water. Furthermore, AM inoculation had highly decreased heavy metal (Zn, Co, Mn, Cu) content in tissues as compared to equivalent non-inoculated plants grown under sewage water application. Growing marigold with AM inoculum can reduce toxicity of heavy metals and enhance biomass production and P uptake. The results support the view that AM have a protective function for the host plant, hence playing a potential function in soil polluted immobilization processes, and thus are of assessing the potential of phytoremediation of heavy metals in sewage water contaminated soil.  相似文献   

2.
Phytohormones have an essential ability to adapt to abiotic stresses, including drought stress (DS), by mediating physiological and molecular processes. Arbuscular mycorrhizas (AMs) can enhance tolerance of DS, but the information regarding phytohormone changes in AM plants exposed to DS is little known. Trifoliate orange (Poncirus trifoliata) seedlings colonized by an AM fungus Funneliformis mosseae were subjected to DS and well-watered for 6 weeks. Plant growth performance, gas exchange, indole-acetic acid (IAA), gibberellins (GAs), brassinosteroids (BRs), abscisic acid (ABA), methyl jasmonate (MeJA) and zeatin riboside (ZR) were determined. The 6-week DS treatment strongly restricted root mycorrhizal colonization. Mycorrhizal inoculation significantly increased plant growth parameters under DS, as compared with non-mycorrhizal treatment. Mycorrhizal treatment also induced significantly higher leaf-relative water content, net photosynthetic rate, transpiration rate and stomatal conductance but lower intercellular CO2 concentration and leaf temperature under DS, compared with non-mycorrhizal treatment. Mycorrhizal plants under DS condition represented significantly higher leaf ABA, IAA, GAs, BRs and ZR levels than non-mycorrhizal plants. The study, hence, suggested that mycorrhizal inoculation induced the changes of gas exchange and endogenous phytohormone levels to enhance drought tolerance in trifoliate orange.  相似文献   

3.
A pot experiment was carried out to study the growth and pungency of Allium fisutulosum grown in Perlite as affected by colonization by the arbuscular mycorrhizal (AM) fungi Glomus etunicatum, Glomus vesiforme, and by ammonium (NH+ 4 ):nitrate (NO? 3 ) ratios of 5:95, 50:50, and 95:5 in 4 mM solutions. Plants were grown in a greenhouse for 20 weeks and then harvested. In general, NH+ 4 :NO? 3 ratio of 50:50 supplied resulted in the highest shoot dry weight regardless of non-mycorrhizal and mycorrhizal plants while the effect of inoculation treatment on plant biomass was not significant. The plant sulfur (S) concentrations were usually higher in mycorrhizal plants than controls irrespective of nitrogen ratio and therefore inoculation with G. etunicatum increased the enzyme produced pyruvic acid (EPY) while inoculation with G. versiforme decreased the EPY compared with the non-mycorrhizal plants. In general, shoot pungency was lowest when NH+ 4 :NO? 3 ratio of 95:5 supplied irrespective of mycorrhizal treatment. Colonization by both AM fungi made a substantial contribution to spring onion sulfur nutrient status but show different way on flavor characteristics of host plants.  相似文献   

4.
Summary The effects of P, N and Ca+Mg fertilization on biomass production, leaf area, root length, vesiculararbuscular mycorrhizal (VAM) colonization, and shoot and root nutrient concentrations of pretransplant rice (Oryza sativa L.) plants were investigated. Mycorrhizal plants generally had a higher biomass and P, N, K, Ca, Mn, Fe, Cu, Na, B, Zn, Al, Mg, and S shoot-tissue nutrient concentrations than non-mycorrhizal plants. Although mycorrhizal plants always had higher root-tissue nutrient concentrations than non-mycorrhizal plants, they were not significantly different, except for Mn. N fertilization stimulated colonization of the root system (colonized root length), and increased biomass production and nutrient concentrations of mycorrhizal plants. Biomass increases due to N were larger when the plants were not fertilized with additional P. P fertilization reduced the colonized root length and biomass production of mycorrhizal plants. The base treatment (Ca+Mg) did not significantly affect biomass production but increased the colonized root length. These results stress the importance of evaluating the VAM rice symbiosis under various fertilization regimes. The results of this study suggest that pretransplant mycorrhizal rice plants may have a potential for better field establishment than non-mycorrhizal plants.  相似文献   

5.
Plants can mediate interactions between aboveground herbivores and belowground decomposers as both groups depend on plant-provided organic carbon. Most vascular plants also form symbiosis with arbuscular mycorrhizal fungi (AMF), which compete for plant carbon too. Our aim was to reveal how defoliation (trimming of plant leaves twice to 6 cm above the soil surface) and mycorrhizal infection (inoculation of the fungus Glomus claroideum BEG31), in nutrient poor and fertilized conditions, affect plant growth and resource allocation. We also tested how these effects can influence the abundance of microbial-feeding animals and nitrogen availability in the soil. We established a 12-wk microcosm study of Plantago lanceolata plants growing in autoclaved soil, into which we constructed a simplified microfood-web including saprotrophic bacteria and fungi and their nematode feeders. We found that fertilization, defoliation and inoculation of the mycorrhizal fungus all decreased P. lanceolata root growth and that fertilization increased leaf production. Plant inflorescence growth was decreased by defoliation and increased by fertilization and AMF inoculation. These results suggest a negative influence of the treatments on P. lanceolata belowground biomass allocation. Of the soil organisms, AMF root colonization decreased with fertilization and increased with defoliation. Fertilization decreased numbers of bacterial-feeding nematodes, probably because fertilized plants produced less root mass. On the other hand, bacterial feeders were more abundant when associated with defoliated than non-defoliated plants despite defoliated plants having less root mass. The AMF inoculation per se increased the abundance of fungal feeders, but the reduced and increased root AM colonization rates of fertilized and defoliated plants, respectively, were not reflected in the numbers of fungal feeders. We found no evidence of plant-mediated effects of the AM fungus on bacterial feeders, and against our prediction, soil inorganic nitrogen concentrations were not positively associated with the concomitant abundances of microbial-feeding animals. Altogether, our results suggest that (1) while defoliation, fertilization and AMF inoculation all affect plant resource allocation, (2) they do not greatly interact with each other. Moreover, it appears that (3) while changes in plant resource allocation due to fertilization and defoliation can influence numbers of bacterial feeders in the soil, (4) these effects may not significantly alter mineral N concentrations in the soil.  相似文献   

6.
To be sustainable, production in the traditional yam cropping system, faced with declining soil fertility, could benefit from yam–arbuscular mycorrhizal (AM) symbiosis, which can improve nutrient uptake, disease resistance, and drought tolerance in plants. However, only limited information exists about AM colonization of yam. A pot experiment was conducted to collect information on the response of two genotypes (Dioscorea rotundata accession TDr 97/00903 and D. alata accession TDa 297) to AM inoculation (with and without) and phosphorus (P) (0, 0.05, 0.5, and 5 mg P kg–1 soil). Factorial combinations of the treatments were arranged in a completely randomized design with four replicates. The percentage of AM colonization was significantly lowered at 5 mg P kg–1 soil rate in mycorrhizal plants of both genotypes. TDr 97/00903 showed more responsiveness to AM inoculation than TDa 297. The greatest AM responsiveness for tuber yield (52%) was obtained at 0.5 mg P kg–1 soil rate for TDr 97/00903. Mycorrhizal inoculation significantly increased root dry weight and tuber yield of TDr 97/00903 with the greatest values obtained at the 0.5 mg P kg–1 soil rate. Arbuscular mycorrhizal inoculation did not lead to significant (P < 0.05) changes in root length and area. Phosphorus application significantly increased the shoot dry weight and root diameter of TDa 297. Uptake of P was greatest at 0.5 mg P kg–1 soil in both genotypes and was significantly influenced by AM inoculation. Nitrogen (N) and potassium (K) uptake were greatest in mycorrhizal plants at 0.05 mg P kg–1 soil for TDr 97/00903 but at 0.5 mg P kg–1 soil of nonmycorrhizal plants of TDa 297. The increased tuber yield and nutrient uptake observed in the mycorrhizal plants indicate the potential for the improvement of nutrient acquisition and tuber yield through AM symbiosis.  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.
Arbuscular mycorrhizal (AM) fungi have been shown to induce the biocontrol of soilborne diseases, to change the composition of root exudates and to modify the bacterial community structure of the rhizosphere, leading to the formation of the mycorrhizosphere. Tomato plants were grown in a compartmentalized soil system and were either submitted to direct mycorrhizal colonization or to enrichment of the soil with exudates collected from mycorrhizal tomato plants, with the corresponding negative controls. Three weeks after planting, the plants were inoculated or not with the soilborne pathogen Phytophthora nicotianae growing through a membrane from an adjacent infected compartment. At harvest, a PCR-Denaturing gradient gel electrophoresis analysis of 16S rRNA gene fragments amplified from the total DNA extracted from each plant rhizosphere was performed. Root colonization with the AM fungi Glomus intraradices or Glomus mosseae induced significant changes in the bacterial community structure of tomato rhizosphere, compared to non-mycorrhizal plants, while enrichment with root exudates collected from mycorrhizal or non-mycorrhizal plants had no effect. Our results support that the effect of AM fungi on rhizosphere bacteria would not be mediated by compounds present in root exudates of mycorrhizal plants but rather by physical or chemical factors associated with the mycelium, volatiles and/or root surface bound substrates. Moreover, infection of mycorrhizal or non-mycorrhizal plants with P. nicotianae did not significantly affect the bacterial community structure suggesting that rhizosphere bacteria would be less sensitive to the pathogen invasion than to mycorrhizal colonization. Of 96 unique sequences detected in the tomato rhizosphere, eight were specific to mycorrhizal fungi, including two Pseudomonas, a Bacillus simplex, an Herbaspirilium and an Acidobacterium. One Verrucomicrobium was common to rhizospheres of mycorrhizal plants and of plants watered with mycorrhizal root exudates.  相似文献   

9.
The effect of salinity on the efficacy of two arbuscular mycorrhizal fungi, Glomus fasciculatum and G. macrocarpum, alone and in combination was investigated on growth, development and nutrition of Acacia auriculiformis. Plants were grown under different salinity levels imposed by 0.3, 0.5 and 1.0 S m-1 solutions of 1 M NaCl. Both mycorrhizal fungi protected the host plant against the detrimental effect of salinity. The extent of AM response on growth as well as root colonization varied with fungal species, and with the level of salinity. Maximum root colonization and spore production was observed with combined inoculation, which resulted in greater plant growth at all salinity levels. AM fungal inoculated plants showed significantly higher root and shoot weights. Greater nutrient acquisition, changes in root morphology, and electrical conductivity of soil in response to AM colonization was observed, and may be possible mechanisms to protect plants from salt stress.  相似文献   

10.
ABSTRACT

A pot experiment was carried out to investigate the tolerance of cucumber plants (Cucumis sativus L.) to root-knot nematode after inoculation with Glomus intraradices. Plants were inoculated with G. intraradices for four weeks and then transplanted in soil treated with Meloidogyne incognita for a further five weeks. The low phosphorus (P) loamy soil was amended with 50 and 100 mg P kg?1 soil. Mycorrhizal colonization increased shoot dry weight, shoot length, leaf numbers, root fresh weight and shoot P concentration, whereas nematode penetration and reproduction were significantly decreased. Similarly, P fertilization usually increased shoot growth and significantly decreased the number of galls and the number of egg masses and eggs per g root. Our results indicate that inoculation with G. intraradices and P fertilizer confer tolerance of cucumber plants to M. incognita by enhancing plant growth and by suppressing reproduction and/or galling of nematodes during the early stages of plant growth.  相似文献   

11.
The influence of inoculation of olive trees with arbuscular mycorrhizal (AM) fungi, Glomus (G) intraradices, on microbial communities and sugar concentrations, were examined in rhizosphere of olive trees (Olea europaea L.). Analyses of phospholipid and neutral lipid fatty acids (PLFA and NLFA, respectively) were then used to detect changes in microbial community structure in response to inoculation of plantlets with G. intraradices.Microscopic observations studies revealed that the extraradical mycelium of the fungus showed formation of branched absorbing structures (BAS) in rhizosphere of olive tree. Root colonization with the AM fungi G. intraradices induced significant changes in the bacterial community structure of olive tree rhizosphere compared to non-mycorrhizal plants. The largest proportional increase was found for the fatty acid 10Me18:0, which indicated an increase in the number of actinomycetes in mycorrhizal rhizosphere soil, whereas the PLFAs i15:0, a15:0, i16:0, 16:1ω7 and cy17:0 which were used as indicators of bacteria decreased in mycorrhizal treatment compared to non-mycorrhizal control treatment. A highest concentration of glucose and trehalose and a lowest concentration of fructose, galactose, sucrose, raffinose and mannitol were detected in mycorrhizal rhizosphere soil. This mycorrhizal effect on rhizosphere communities may be a consequence of changes in characteristics in the environment close to mycorrhizal roots.  相似文献   

12.
Arbuscular mycorrhizal fungi (AMF) as a biostimulant enhance salt tolerance in plants, while the informations regarding AMF-induced changes in soil structure are only available to a limited degree. In this study, trifoliate orange (Poncirus trifoliata) seedlings were inoculated with Diversispora versiformis under 100 mM NaCl for 85 days. The salt stress considerably inhibited mycorrhizal colonization by 26%, compared with non-salt stress. Mycorrhizal inoculation significantly increased plant height, stem diameter, leaf number, shoot biomass, and root biomass, length, surface area, and volume in comparison to non-mycorrhizal inoculation under salt stress or non-salt stress. Mycorrhization induced significantly higher production of easily extractable glomalin-related soil protein (EE-GRSP), and total glomalin-related soil protein (T-GRSP), higher percentage of water-stable aggregates (WSAs) in 0.25–0.50, 0.50–1.00, and 1.00–2.00 mm size, and lower in 2.00–4.00 mm size, regardless of non-salt stress or salt stress. Mycorrhizal soils represented higher aggregate stability (in terms of mean weight diameter) under salt and non-salt stress, which was related with root colonization, root surface area, root volume, EE-GRSP, and T-GRSP. The better soil structure by mycorrhization provided higher leaf water potential under salt stress. It suggests that mycorrhizas had a positive contribution to improve plant growth and soil structure, thereby enhancing salt tolerance.  相似文献   

13.
丛枝菌根真菌对棉花耐盐性的影响研究   总被引：17，自引：2，他引：17       下载免费PDF全文
盆栽灭菌试验研究丛枝(AM)真菌对棉花耐盐性的影响结果表明,自然盐渍化土壤和人工模拟盐渍条件下接种AM真菌处理的生物产量显著高于不接种处理,相同土壤下菌根真菌对棉花植株生长的促进作用随盐水平的提高而增大,表明AM真菌与植株建立的共生关系有利于棉花在盐渍土壤中生长。盐胁迫下棉花植株对P的需要量增加,接种AM真菌可提高植株含P量,促进植株生长,提高棉花的耐盐性。  相似文献   

14.
Maize (Zea mays L.) and sorghum (Sorghum bicolor L.) Moench (local variety called Masakwat) plants were grown in a sterilized low-P soil in the greenhouse for 12 weeks. Each plant species was either mycorrhizal with vesicular-arbuscular mycorrhizal (VAM) fungi, non-mycorrhizal but minimally fertilized with soluble P, or non-mycorrhizal but highly fertilized with soluble P. Drought stress was imposed after 4 weeks at weekly intervals. Under unstressed conditions, leaf area, shoot dry weights, xylem pressure, and soil water potentials were similar for VAM and the two non-mycorrhizal P-fertilized treatments but each of the VAM-infected species had a greater total root length. Total P uptake was similar for the maize treatments but higher for VAM than non-mycorrhizal P-fertilized sorghum treatments. Under drought-stressed conditions, the growth parameters and soil water potential were similar for all maize treatments but they were reduced by mycorrhizal inoculation in sorghum. Greater water extraction occurred in drought-stressed mycorrhizal sorghum. In both plant species, total P uptake and P uptake per unit root length (including unstressed species) were significantly enhanced in non-mycorrhizal P-fertilized treatments compared with the mycorrhizal treatment. Except for the root dry weight of sorghum plants, there were no differences in the growth parameters and P uptake between minimally and highly P-fertilized non-mycorrhizal treatments for either maize or sorghum. The increased total root length in drought-stressed mycorrhizal sorghum plants and the similar infected root lengths in unstressed and drought-stressed sorghum plants may have caused high C partitioning to drought-stressed mycorrhizal roots and therefore caused the reduced growth parameters in mycorrhizal plants compared to the non-mycorrhizal P-fertilized counterparts. The results indicate that P fertilization in addition to mycorrhizal inoculation may improve the drought tolerance of maize and sorghum plants.  相似文献   

15.
A greenhouse experiment was carried out during the spring–summer 2009 to test the hypotheses that: (1) arbuscular‐mycorrhizal (AM) inoculation with a biofertilizer containing Glomus intraradices gives an advantage to overcome alkalinity problems, (2) mineral fertilization is more detrimental to AM development than organic fertilization on an equivalent nutrient basis. Arbuscular mycorrhizal (AM) and non‐AM of zucchini (Cucurbita pepo L.) plants were grown in sand culture with two pH levels in the nutrient solution (6.0 or 8.1) and two fertilization regimes (organic or mineral). The high‐pH nutrient solution had the same basic composition as the low‐pH solution, plus an additional 10 mM NaHCO3 and 0.5 g L–1 CaCO3. Increasing the concentration of NaHCO3 from 0 to 10 mM in the nutrient solution significantly decreased yield, plant growth, SPAD index, net assimilation of CO2 (ACO2), N, P, Ca, Mg, Fe, Mn, and Zn concentration in leaf tissue. The +AM plants under alkaline conditions had higher total, marketable yield and total biomass compared to –AM plants. The higher yield and biomass production in +AM plants seems to be related to the capacity of maintaining higher SPAD index, net ACO2, and to a better nutritional status (high P, K, Fe, Mn, and Zn and low Na accumulation) in response to bicarbonate stress with respect to –AM plants. The percentage root colonization was significantly higher in organic‐fertilized (35.7%) than in mineral‐fertilized plants (11.7%). Even though the AM root colonization was higher in organic‐fertilized plants, the highest yield and biomass production were observed in mineral‐fertilized plants due to the better nutritional status (higher N, P, Ca, and Mg), higher leaf area, SPAD index, and ACO2.  相似文献   

16.
 The effect of the interaction between a vesicular-arbuscular (VA)-mycorrhiza (Glomus intraradices no. LAP8) and Streptomyces coelicolor strain no. 2389 on the growth response, nutrition and metabolic activities of sorghum (Sorghum bicolor) plants grown in non-sterilized soil amended with chitin waste was studied in a greenhouse over 8 weeks. Chitin amendment resulted in an increase in the microbial population and chitinase activity in soils. Growth of mycorrhizal G. intraradices no. LAP8 and non-mycorrhizal sorghum plants increased as compared with other treatments either in the presence or absence of S. coelicolor strain 2389. VA-mycorrhizal inoculation significantly increased the growth, photosynthetic pigments, total soluble protein and nutrient contents of sorghum compared to non-mycorrhizal sorghum. Such increases were related to increased mycorrhizal colonization. Inoculation with S. coelicolor 2389 significantly increased the intensity of mycorrhizal root colonization and arbuscular formation, but the levels of mycorrhizal infection and their beneficial effects were significantly reduced with the addition of chitin waste to the soil. Analysis of the content of total amino acids and ammonia in leaves on the basis of dry matter production showed that, in most instances, total amino acids of mycorrhizal plants were significantly higher than those of non-inoculated plants. The microflora of the rhizosphere was highly affected by mycorrhizal inoculation. Quantitative changes in acid and alkaline phosphatase activities of the roots in response to the mycorrhizal inoculation are discussed. Received: 11 August 1999  相似文献   

17.
ABSTRACT

Arbuscular mycorrhizal (AM) fungi can improve plant phosphorus (P) uptake; however, information about how AM fungi affect rhizosphere organic acid and microbial activity to alleviate citrus low P stress is limited. Here, a pot experiment was conducted to evaluate the effect of AM fungi (Rhizophagus intraradices, Ri) inoculation on rhizosphere organic acid content, microbial biomass (MB) and enzyme activity of trifoliate orange (Poncirus trifoliata L. Raf.) seedlings grown under three low P conditions. The results showed that mycorrhizal seedlings all recorded higher P concentrations, plant biomass and better root morphology with more lateral and fine roots, but lower root mass ratios, irrespective of P conditions. Mycorrhizal P absorption contribution did not differ significantly among three P conditions. Mycorrhizal seedling rhizosphere soil exhibited lower organic acid content, soil organic P content and ratio of MB-carbon (C)/MB-P, but higher MB and enzyme activity. Additionally, the main organic acids showed a negative relationship with mycorrhizal colonization rate and hyphal length; however, phosphatase and phytase activity had a significantly positive relationship with MB. Therefore, the results suggest that AM fungi inoculation may help citrus to efficiently utilize organic P source by improving microbial activity under low available P conditions.  相似文献   

18.
The complex biological interactions taking place in soil–plant systems may sometimes alter the functioning of an ecosystem. We examined the relationship between arbuscular mycorrhizal (AM) root colonization, nematode populations, and plant competition in an 8-year-old field experiment comparing alfalfa monoculture to dual culture of alfalfa (Medicago sativa L.) and Russian wildrye (Psathyostachys juncea Fisch. Nevski) (RWR) grown under different soil P fertility levels, in a Brown Chernozemic soil in Saskatchewan. The experiment included three P rates: 0, 20 and 40 kg P2O5 ha−1 (0P, 20P and 40P) applied annually and was sampled three times during the cropping season: 30 June, 1 September and 30 September. Higher AM symbiotic development compensated for reduced soil P fertility in alfalfa stands without RWR and forage dry matter yield was not affected by P rates. But in the presence of RWR, reduced soil P fertility at 0P and 20P led to forage yield reduction. Fertilization treatments modified the soil microbial community structure only in the presence of RWR, as revealed by discriminant analysis of the profiles of microbial phospholipids fatty acid in soil lipid extracts and functional nematode groups. Arbuscular mycorrhizal root colonization level was reduced with P fertilizer both in the presence and absence of RWR. In the presence of RWR, lower plant AM root colonization was concurrent with higher abundance of total, fungivorous and omnivorous nematodes. Our results are consistent with a model of negative feedback from the plant-associated soil microflora where the presence of RWR increased the population of fungivorous nematodes and grazing of AM hyphae. Negative impacts were larger in low P fertility soils promoting AM symbiotic development. The unexpected decrease in alfalfa–RWR dual culture yield under 0P and 20P fertilization levels was attributed to a carbon drain created by enhanced nematode feeding on AM fungi in the presence of RWR.  相似文献   

19.
接种丛枝菌根真菌(AMF)能显著促进大豆生长和对磷的吸收,但不同磷效率基因型大豆对AMF接种的响应还少有报道。为探究接种AMF对不同磷效率基因型大豆生长和磷转运基因表达的影响,以磷高效大豆BX10和磷低效大豆BD2为试验材料进行盆栽试验,设置接菌和不接菌处理,对大豆干重、菌根侵染性状、氮磷养分含量、根系性状,以及菌根诱导的磷转运基因表达进行了分析。结果表明, AMF接种显著促进了大豆的磷吸收,并且接菌效果存在显著的基因型差异,接种AMF显著增加了BD2的地上部干重、磷含量以及植株总磷吸收量,但只增加了BX10的地上部磷含量和总磷吸收量,对植株地上部干重没有显著影响。无论接种与否,BD2的地上部磷含量均显著高于BX10,表明磷低效的BD2具有较高的植株体内磷转运能力。不接菌条件下,两个大豆基因型根系性状无显著差异;接种AMF后BX10的根系体积和根系平均直径均显著高于BD2。BD2的菌根生长反应(MGR)和菌根磷反应(MPR)均显著高于BX10,对菌根依赖性更高。此外,在接菌处理的BD2根系,代表菌根途径磷吸收的磷转运基因GmPT8、GmPT9和GmPT10表达均显著高于BX10;相应地,BD2的总磷吸收量也显著高于BX10。以上结果表明,接种AMF对促进磷低效大豆BD2生长和磷吸收的作用更大,这可能主要是由于BD2菌根途径的磷吸收量较高,体内磷转运效率较高。以上结果将为研究AMF接种对磷吸收的贡献提供理论依据。  相似文献   

20.
Effects of inoculation with three different arbuscular mycorrhizal (AM) fungi (Glomus etunicatum, Glomus constrictum, and Glomus mosseae) on arsenic (As) accumulation by maize were investigated by using soil spiked with As at rates of 0, 25, 50, and 100 mg kg?1. The root colonization rates by the three fungi were significantly different (G. mosseae > G. etunicatum > G. constrictum) and decreased markedly with increasing As concentration in the soil. Inoculation with G. etunicatum or G. mosseae increased maize biomass and phosphorus (P) accumulation (G. mosseae > G. etunicatum) and reduced As accumulation in shoots (G. mosseae ≈ G. etunicatum), whereas inoculation with G. constrictum had little effect on these parameters. Inoculation with G. mosseae produced greater biomass and P uptake and less shoot As accumulation, and therefore it may be a promising approach to reduce As translocation from contaminated soils to plants.  相似文献   

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