Effects of Glomus fasciculatum and isolated rhizosphere microorganisms on growth and phosphate uptake of Plantago major ssp. pleiosperma

An experiment was set up in order to study 1) the relationship between net P uptake and dry matter production in mycorrhizal and non-mycorrhizal plants and 2) the effects of isolated rhizosphere bacteria and fungi on net P uptake and growth of P. major ssp. pleiosperma. A similar relationship between net P uptake and dry matter production was found for both mycorrhizal and non-mycorrhizal plants, although the regression lines differed in intercept.Compared to non-inoculated treatments, inoculation with bacteria slightly decreased dry matter production and P uptake of P. major, whereas inoculation with fungi or bacteria + fungi showed no effect. The results are discussed in terms of competition for available P and host photosynthates between host plant and rhizosphere microorganisms.     

Arbuscular mycorrhizal fungi from three genera induce two-phase plant growth responses on a high P-fixing soil

Plant growth enhancing effects of arbuscular mycorrhizal (AM) fungi are suitably quantified by comparisons of mycorrhizal and non-mycorrhizal plant growth responses to added phosphorus (P). The ratio between the amounts of added P required for the same yield of mycorrhizal and non-mycorrhizal plants is termed the relative effectiveness of the mycorrhiza. Variation in this relative effectiveness was examined for subterranean clover grown on a high P-fixing soil. Plants were either left non-mycorrhizal or inoculated with one of three AM fungal species with well-characterised differences in external hyphal spread. With no P added, plants from all treatments produced <10% of their maximum growth achieved at non-limiting P supply. The growth response of non-mycorrhizal plants was markedly sigmoid. Mycorrhizal growth responses were not sigmoid but their shape was two-phased. The first phase was an asymptotic approach to 25–30% of maximum growth, followed by a second asymptotic rise to maximum growth. Growth effects of Glomus invermaium and Acaulospora laevis were quite similar. Plants in these treatments produced up to four times greater shoot dry biomass than non-mycorrhizal plants. Scutellospora calospora was less effective. The relative effectiveness of AM fungi varied with the level of P application. This is expected to apply to all soils on which a sigmoid response is obtained for growth of non-mycorrhizal plants. In a simple approximation the relative effectiveness was calculated to range from 1.46 to 15.57. Shoot P contents were increased by up to 25 times by A. laevis, significantly more than by the other two fungi. The further mycelial spread of this fungus is thought to have contributed to its relatively greater effect on plant P content.     

Seed phosphorus (P) content affects growth,and P uptake of wheat plants and their association with arbuscular mycorrhizal (AM) fungi

Two experiments were carried out in a growth chamber and a naturally lit glasshouse to investigate the influence of seed phosphorus (P) reserves on growth and P uptake by wheat plants (Triticum aestivum cv Krichauff), and their association with arbuscular mycorrhizal (AM) fungi. Increased seed P reserves improved plant growth at a range of P supply up to over 100 mg P kg^–1 soil. Plants grown from seeds with high P reserves tended to accumulate more P from soil, which was mainly attributed to better root system development. Mycorrhizal colonisation did not significantly affect P uptake of plants grown with low irradiance (in growth chamber). However, in the naturally lit glasshouse, mycorrhizal plants had significantly higher P concentrations than non-mycorrhizal plants. Furthermore, mycorrhizal plants grown from seeds low in P accumulated similar amounts of P compared with those grown from seeds with high P, indicating that mycorrhizal colonisation may overcome the disadvantage of having low seed P reserves in the field.     

Mycorrhizal inoculant alleviates salt stress in<Emphasis Type="Italic"> Sesbania aegyptiaca</Emphasis> and<Emphasis Type="Italic"> Sesbania grandiflora</Emphasis> under field conditions: evidence for reduced sodium and improved magnesium uptake

A field experiment was conducted to examine the effect of the arbuscular mycorrhizal fungus Glomus macrocarpum and salinity on growth of Sesbania aegyptiaca and S. grandiflora. In the salt-stressed soil, mycorrhizal root colonisation and sporulation was significantly higher in AM-inoculated than in uninoculated plants. Mycorrhizal seedlings had significantly higher root and shoot dry biomass production than non-mycorrhizal seedlings grown in saline soil. The content of chlorophyll was greater in the leaves of mycorrhiza-inoculated as compared to uninoculated seedlings. The number of nodules was significantly higher in mycorrhizal than non-mycorrhizal plants. Mycorrhizal seedling tissue had significantly increased concentrations of P, N and Mg but lower Na concentration than non-mycorrhizal seedlings. Under salinity stress conditions both Sesbania sp. showed a high degree of dependence on mycorrhizae, increasing with the age of the plants. The reduction in Na uptake together with a concomitant increase in P, N and Mg absorption and high chlorophyll content in mycorrhizal plants may be important salt-alleviating mechanisms for plants growing in saline soil.     

Effects of elevated nickel and cadmium concentrations on growth and nutrient uptake of mycorrhizal and non-mycorrhizal Pinus sylvestris seedlings

The effects of Ni and Cd on growth and nutrient uptake of mycorrhizal and non-mycorrhizal Pinus sylvestris L. seedlings were investigated in a pot experiment. Seedlings were either inoculated with Laccaria bicolor (Maire) Orton or left uninoculated before being planted in pots containing a mixture of sandy soil from the B-horizon of a coniferous forest, small stones and pure quartz sand. The pots were supplied with small amounts of a balanced nutrient solution every 24 h using peristaltic pumps. Nickel or Cd were added as chlorides to the nutrient solution at levels of 85 M Ni (Ni 1), 170 M Ni (Ni 2), or 8.9 M Cd. Mycorrhizal colonisation of the roots was nearly 100% in the mycorrhizal treatments. The mycorrhizal seedlings grew significantly better than the non-mycorrhizal ones. The weight of mycorrhizal seedlings in the Ni 2 treatment was 29% lower than that of the mycorrhizal controls, but still 34% greater than that of the non-mycorrhizal seedlings not exposed to metals. There was an overall, statistically significant, negative effect of metals on plant yield. Mycorrhizal plants had lower root:shoot (R:S) ratios than non-mycorrhizal plants and the R:S ratio was increased by metal exposure, particularly in the non-mycorrhizal seedlings. Plant concentrations of Cd or Ni were not affected by mycorrhizal colonisation, but total uptake of Cd and Ni was higher in bigger mycorrhizal seedlings. Nickel decreased P concentration in all seedlings and Cd decreased P concentration in the non-mycorrhizal seedlings. Generally, the mycorrhizal seedlings grew better than non-mycorrhizal ones and had better P, K, Mg and S status. Root growth was not significantly affected by the metal treatments. The reduction in mean shoot growth of non-mycorrhizal plants, relative to the metal-free control, appeared higher than in mycorrhizal plants but was not statistically significant due to high variation in the non-mycorrhizal plants not exposed to metals. The main mycorrhizal effect was thus increased nutrient uptake and growth of the seedlings.     

Arbuscular mycorrhiza reduces susceptibility of tomato to Alternaria solani

Mycorrhiza frequently leads to the control of root pathogens, but appears to have the opposite effect on leaf pathogens. In this study, we studied mycorrhizal effects on the development of early blight in tomato (Solanum lycopersicum) caused by the necrotrophic fungus Alternaria solani. Alternaria-induced necrosis and chlorosis of all leaves were studied in mycorrhizal and non-mycorrhizal plants over time course and at different soil P levels. Mycorrhizal tomato plants had significantly less A. solani symptoms than non-mycorrhizal plants, but neither plant growth nor phosphate uptake was enhanced by mycorrhizas. An increased P supply had no effect on disease severity in non-mycorrhizal plants, but led to a higher disease severity in mycorrhizal plants. This was parallel to a P-supply-induced reduction in mycorrhiza formation. The protective effect of mycorrhizas towards development of A. solani has some parallels to induced systemic resistance, mediated by rhizobacteria: both biocontrol agents are root-associated organisms and both are effective against necrotrophic pathogens. The possible mechanisms involved are discussed.     

Effects of liming and mycorrhizal colonization on soil phosphate depletion and phosphate uptake by maize (Zea mays L.) and soybean (Glycine max L.) grown in two tropical acid soils

The effects of liming and inoculation with the arbuscular mycorrhizal fungus, Glomus intraradices Schenck and Smith on the uptake of phosphate (P) by maize (Zea mays L.) and soybean (Glycine max [L.] Merr.) and on depletion of inorganic phosphate fractions in rhizosphere soil (Al-P, Fe-P, and Ca-P) were studied in flat plastic containers using two acid soils, an Oxisol and an Ultisol, from Indonesia. The bulk soil pH was adjusted in both soils to 4.7, 5.6, and 6.4 by liming with different amounts of CaCO₃.In both soils, liming increased shoot dry weight, total root length, and mycorrhizal colonization of roots in the two plant species. Mycorrhizal inoculation significantly increased root dry weight in some cases, but much more markedly increased shoot dry weight and P concentration in shoot and roots, and also the calculated P uptake per unit root length. In the rhizosphere soil of mycorrhizal and non-mycorrhizal plants, the depletion of Al-P, Fe-P, and Ca-P depended in some cases on the soil pH. At all pH levels, the extent of P depletion in the rhizosphere soil was greater in mycorrhizal than in non-mycorrhizal plants. Despite these quantitative differences in exploitation of soil P, mycorrhizal roots used the same inorganic P sources as non-mycorrhizal roots. These results do not suggest that mycorrhizal roots have specific properties for P solubilization. Rather, the efficient P uptake from soil solution by the roots determines the effectiveness of the use of the different soil P sources. The results indicate also that both liming and mycorrhizal colonization are important for enhancing P uptake and plant growth in tropical acid soils.     

Increased drought tolerance of mycorrhizal onion plants caused by improved phosphorus nutrition

Onion plants (Allium cepa L, cv. Downing Yellow Globe) grown in pots and infected by the mycorrhizal fungusGlomus etunicatus Becker and Gerdemann were more drought tolerant than were non-mycorrhizal individials when exposed to several periods of soil water stress separated by periods of high water supply, as shown by greater fresh and dry weights and higher tissue phosphorus levels in the mycorrhizal plants. The tissues of stressed, non-mycorrhizal plants were deficient in P, despite the fact that only non-mycorrhizal plants were fertilized with high levels of P (26 mg P per 440 g soil). Differences in plant water relations (leaf water potentials or transpiration rates) and changes in soil P levels which may have affected plant growth were investigated, and discounted as factors important for the results. The P nutrition of plants has been implicated in the ability of plants to tolerate drought and it was concluded that the ability of the mycorrhizal fungus to maintain adequate P nutrition in the onions during soil water stress was a major factor in the improved drought tolerance. Infection of the root by the fungus was found not to be affected by water stress or P fertilization but fungal reproduction, as determined by spore numbers in the soil, was decreased by water stress and by P fertilization.Michigan Agricultural Experiment Station Article No. 10050     

Effectiveness of three Glomus species in protecting pepper (Capsicum annuum L.) against verticillium wilt

The objective of this work was to study the influence of three Glomus species—Glomus mosseae (Nicol. and Gerd.) Gerd. and Trappe, Glomus intraradices (Schenck and Smith) and Glomus deserticola (Trappe, Bloss, and Menge)—on the development of Verticillium-induced wilt in Capsicum annuum cv. Piquillo. Results showed that the effectiveness of arbuscular mycorrhizal fungi (AMF) as biocontrol agents varied among different Glomus species. In pepper colonized by G. intraradices the severity of the disease was even higher than that observed in non-mycorrhizal plants in terms of plant growth and pepper yield. On the other hand, the high effectiveness exhibited by G. mosseae in improving plant growth and the early beginning of the reproductive stage in these plants was not associated with great plant protection and high pepper yield in diseased plants. Only plants associated with G. deserticola had greater yield than non-mycorrhizal ones despite the lower P fertilization applied to the mycorrhizal treatment and this fact was observed in both healthy and diseased plants. It is suggested that the higher specific phosphorus uptake in Verticillium-inoculated plants associated with G. deserticola could contribute to diminish the deleterious effect of pathogen on yield. On the other hand, the possible influence of endogenous phenolics in roots on the tolerance or resistance of pepper against wilt induced by Verticillium dahliae remains unclear.     

Differential responses of three fungal species to environmental factors and their role in the mycorrhization of<Emphasis Type="Italic"> Pinus radiata</Emphasis> D. Don

Three ectomycorrhizal (ECM) isolates of Rhizopogon luteolus, R. roseolus and Scleroderma citrinum were found to differ markedly in their in vitro tolerance to adverse conditions limiting fungal growth, i.e. water availability, pH and heavy metal pollution. S. citrinum was the most sensitive, R. luteolus intermediate and R. roseolus the most tolerant species. Pinus radiata D. Don seedlings were inoculated in the laboratory and in a containerised seedling nursery with spore suspensions of the three ECM species. Colonisation percentage was considerably lower under nursery conditions, probably due to competition by native fungi. The effects of nursery ECM inoculation on seedling growth depended on the fungal species. Only R. roseolus-colonised plants showed a significantly higher shoot growth than non-mycorrhizal plants. All three fungi induced significantly higher root dry weights relative to control plants. Despite the low mycorrhizal colonisation, mycorrhization with all three species improved the physiological status of nursery-grown seedlings, e.g. enhanced root enzyme activity, shoot nutrient and pigment content, net photosynthesis rate and water use efficiency. Of the three fungal species, R. roseolus was the most effective; this species was also the most adaptable and showed the greatest range of tolerance to adverse environmental conditions in pure culture. It is, therefore, proposed as a promising fungal species for ECM inoculation of P. radiata in the nursery.     

Effects of the root-lesion nematode Pratylenchus vulnus and the vesicular-arbuscular mycorrhizal fungus Glomus mosseae on the growth of three plum rootstocks

The effects of Pratylenchus vulnus and the endomycorrhizal fungus Glomus mosseae on growth of Myrobalan 605, Marianna 2624 and San Julian 655-2 plum rootstocks were measured under shadehouse conditions in the field for two growing seasons (1990–91). Shoot dry weights were higher in the majority of the vesicular-arbuscular mycorrhizal (VAM) alone inoculated plants after both growing seasons. Root weights of mycorrhizal Myrobalan and Marianna were higher than root weights of the same rootstocks lacking mycorrhizae, inoculated with P. vulnus, and VAM in combination with the nematode. Mycorrhizal Marianna inoculated with the nematode showed a considerably higher final nematode population in relation to non-inoculated VAM treatments. No correlation was found in the number of nematodes per gram of root between mycorrhizal and non-mycorrhizal treatments. P. vulnus adversely affected the mycorrhizal colonization in Marianna, but not in Myrobalan and San Julian. Marianna appears to be more mycorrhizal dependent than the two other rootstocks.     

Effects of different N fertilizers on the activity of <Emphasis Type="Italic">Glomus mosseae</Emphasis> and on grapevine nutrition and berry composition

Grapevine N fertilization may affect and be affected by arbuscular mycorrhizal (AM) fungal colonization and change berry composition. We studied the effects of different N fertilizers on AM fungal grapevine root colonization and sporulation, and on grapevine growth, nutrition, and berry composition, by conducting a 3.5-year pot study supplying grapevine plants with either urea, calcium nitrate, ammonium sulfate, or ammonium nitrate. We measured the percentage of AM fungal root colonization, AM fungal sporulation, grapevine shoot dry weight and number of leaves, nutrient composition (macro- and micronutrients), and grapevine berry soluble solids (total sugars or °Brix) and total acidity. Urea suppressed AM fungal root colonization and sporulation. Mycorrhizal grapevine plants had higher shoot dry weight and number of leaves than non-mycorrhizal and with a higher growth response with calcium nitrate as the N source. For the macronutrients P and K, and for the micronutrient B, leaf concentration was higher in mycorrhizal plants. Non-mycorrhizal plants had higher concentration of microelements Zn, Mn, Fe, and Cu than mycorrhizal. There were no differences in soluble solids (°Brix) in grapevine berries among mycorrhizal and non-mycorrhizal plants. However, non-mycorrhizal grapevine berries had higher acid content with ammonium nitrate, although they did not have better N nutrition and vegetative growth.     

Mycorrhizal association of Glomus aggregatum with palmarosa enhances growth and biomass

Palmarosa (Cymbopogon martinii var. motia) was found to be associated with a vesicular-arbuscular mycorrhizal (VAM) fungus, Glomus aggregatum. Glasshouse experiments showed that inoculation of palmarosa with G. aggregatum caused a two-fold growth and three-fold biomass production as compared to non-mycorrhizal plants. These findings indicate the potential use of VAM-fungi for improving the production of this essential oil bearing plant.CIMAP Publication No. 879.CIMAP Publication No. 879.     

Tolerance ofFestuca rubra L. to zinc in relation to mycorrhizal infection

Summary Plant yield of mycorrhizal and non-mycorrhizalFestuca rubra L. was linearly decreased with increasing zinc concentrations in nutrient solution. In all cases, non-mycorrhizal plant growth was significantly greater than that of mycorrhizal plants. Zinc and phosphorus concentrations of root and shoot of mycorrhizal plants were greater in all zinc treatments while mycorrhizal plants showed equal or lower tolerance indices to zinc than non-mycorrhizal plants. Yield depressions of mycorrhizal plants may be the result of enhanced zinc and phosphorus concentrations combined with the cost for growth and maintenance of the mycorrhizal fungi.     

Indigenous and introduced arbuscular mycorrhizal fungi contribute to plant growth in two agricultural soils from south-western Australia

Arbuscular mycorrhizal (AM) fungi occur in all agricultural soils but it is not easy to assess the contribution they make to plant growth under field conditions. Several approaches have been used to investigate this, including the comparison of plant growth in the presence or absence of naturally occurring AM fungi following soil fumigation or application of fungicides. However, treatments such as these may change soil characteristics other than factors directly involving AM fungi and lead to difficulties in identifying the reason for changes in plant growth. In a glasshouse experiment, we assessed the contribution of indigenous AM fungi to growth of subterranean clover in undisturbed cores of soil from two agricultural field sites (a cropped agricultural field at South Carrabin and a low input pasture at Westdale). We used the approach of estimating the benefit of AM fungi by comparing the curvature coefficients ( C) of the Mitscherlich equation for subterranean clover grown in untreated field soil, in field soil into which inoculum of Glomus invermaium was added and in soil fumigated with methyl bromide. It was only possible to estimate the benefit of mycorrhizas using this approach for one soil (Westdale) because it was the only soil for which a Mitscherlich response to the application of a range of P levels was obtained. The mycorrhizal benefit ( C of mycorrhizal vs. non-mycorrhizal plants or C of inoculated vs. uninoculated plants) of the indigenous fungi corresponded with a requirement for phosphate by plants that were colonised by AM fungi already present in the soil equivalent to half that required by non-mycorrhizal plants. This benefit was independent of the plant-available P in the soil. There was no additional benefit of inoculation on plant growth other than that due to increased P uptake. Indigenous AM fungi were present in both soils and colonised a high proportion of roots in both soils. There was a higher diversity of morphotypes of mycorrhizal fungi in roots of plants grown in the Westdale soil than in the South Carrabin soil that had a history of high phosphate fertilizer use in the field. Inoculation with G. invermaium did not increase the level of colonisation of roots by mycorrhizal fungi in either soil, but it replaced approximately 20% of the root length colonised by the indigenous fungi in Westdale soil at all levels of applied P. The proportion of colonised root length replaced by G. invermaium in South Carrabin soil varied with the level of application of P to the soil; it was higher at intermediate levels of recently added soil P.     

Interaction between the root-lesion nematode Pratylenchus vulnus and the mycorrhizal association of Glomus intraradices and Santa Lucia 64 cherry rootstock

The effects of the interaction between Pratylenchus vulnus and the endomycorrhizal fungus Glomus intraradices on growth and nutrition of Santa Lucia 64 cherry rootstock was studied under microplot conditions during one growing season. Fresh top weight, and stem diameter of mycorrhizal plants and high P treatments with and without P. vulnus were significantly higher than those of non-mycorrhizal plants. The lowest shoot length and fresh root weights were recorded in nematode inoculated plants in low P soil. Mycorrhizal infection did not affect the number of nematodes per gram of root in plants infected with P. vulnus. In the presence of the nematode, internal spore production by G. intraradices was significantly reduced. No nutrient deficiencies were detected through foliar analysis, although low levels of Ca, Mn and Fe were detected in nematode treatments. Mycorrhizal plants achieved the highest values for N, P, S, Fe, and Zn, whereas high P treatments increased absorption of Ca and Mn. Early mycorrhizal infection of Santa Lucia 64 cherry rootstock by G. intraradices confers increased growth capacity in the presence of P. vulnus.     

Vesicular arbuscular mycorrhizal mediation of grass response to acidic and heavy metal depositions

Summary The perennial bunchgrassEhrharta calycina was grown with and without V.A.M. fungal infection (Glomus fasciculatum) in a sandy loam exposed to a range of acidic and heavy metal depositions. Heavy metals (Cu, Ni, Pb, Zn, Fe, and Co) were applied in simulated rain (pH 3.0, 4.0, and 5.6) at deposition rates approximating those observed to result from smelter efluents. Metal concentrations in the roots and shoots of mycorrhizal plants were greater than those of non-mycorrhizal plants. Mycorrhizal enhancement of plant metal uptake increased with greater acidity and higher heavy metal content of treatment. The growth of mycorrhizal plants was reduced compared to non-mycorrhizal plants when metal depostion was combined with simulated acid rain. We propose that mycorrhizal enhancement of heavy metal uptake caused reduced growth in plants exposed to acidic and heavy metal depositions.     

The effect of aluminium on the distribution of calcium,magnesium and phosphorus in mycorrhizal and non-mycorrhizal seedlings of Eucalyptus rudis: a cryo-microanalytical study

The distribution of Al, Ca, Mg and P in the lateral roots and leaves of mycorrhizal and non-mycorrhizal seedlings of Eucalyptus rudis grown with and without Al was analysed using energy-dispersive X-ray microanalysis on a cryo-scanning electron microscope. Al accumulated in all tissues of nonmycorrhizal plants: the endodermis was not a barrier to the translocation of Al. In mycorrhizal roots, Al was concentrated within the sheath. The presence of Al reduced the levels of Ca and Mg in both mycorrhizal and non-mycorrhizal roots and shoots in comparison with control plants. The presence of mycorrhizas increased the levels of Ca and Mg in plants grown with Al in comparison with non-inoculated plants, although there was no evidence that mycorrhizas increased the levels of P in plants grown in Al-amended soils. P levels were higher in the mycorrhizal sheath of plants grown with Al than the controls.     

Growth response and phosphorus uptake of rye with long and short root hairs: Interactions with mycorrhizal infection

Plant growth and phosphorus (P) uptake of two selections of rye (Secale cereale L.) differing in length of root hairs, in response to mycorrhizal infection were investigated. Rye plants with short root hairs (SRH) had a greater length of root infected by Glomus intraradices (up to 32 m pot^–1) than those with long root hairs (LRH) (up to 10 m pot^–1). Application of P decreased the percentage of root length infected in both selections. In low-P soil, mycorrhizal infection increased shoot and root P concentration, especially in LRH plants. Generally, LRH had higher shoot dry weight than SRH plants. P uptake was increased both by LRH and by mycorrhizal infection. Differences in specific P uptake and P utilization efficiency between SRH and LRH plants were observed in non-mycorrhizal plants. With low P supply, P utilization efficiency (dry matter yield per unit of P taken up) of LRH plants increased with time. However, mycorrhizal infection reduced P utilization efficiency, particularly of SRH plants. SRH plants, which were agronomically less efficient (i.e. low dry matter yield at low P supply) were more responsive to either mycorrhizal infection or P addition than the LRH plants. No interaction was observed between mycorrhizal infection and root hair length.     

Arbuscular mycorrhizal fungal application to improve growth and tolerance of wheat (Triticum aestivum L.) plants grown in saline soil

A pot experiment was conducted to examine the effects of three different arbuscular mycorrhizal fungi, Glomus mosseae, G. deserticola and Gigaspora gergaria, on growth and nutrition of wheat (Triticum aestivium L. cv. Henta) plants grown in saline soil. Under saline condition, mycorrhizal inoculation significantly increased growth responses, nutrient contents, acid and alkaline phosphatases, proline and total soluble protein of wheat plants compared to non-mycorrhizal ones. Those stimulations were related to the metabolic activity of the each mycorrhizal fungus. The localization of succinate dehydrogenase “SDH” (as a vital stain for the metabolically active fungus) in the arbuscular mycorrhizal fungi was variable. In general, mycorrhizal shoot plant tissues had significantly higher concentrations of P, N, K and Mg but lower Na concentration than those of non-mycorrhizal plants. In saline soil, growth and nutrition of wheat plants showed a high degree of dependency on mycorrhizal fungi (especially G. mosseae). The use of the nitroblue tetrazolium chloride method as a vital stain for SDH activity showed that all the structures of mycorrhizal infections in the wheat plant estimated by the trypan blue staining (non-vital stain) were not metabolically active. Interestingly, the reduction in Na uptake along with associated increases in P, N and Mg absorption and high proline, phosphatase activities and chlorophyll content in the mycorrhizal plants could be important for salt alleviation in plants growing in saline soils.