Effects Of Vesicular-arbuscular Mycorrhizae Research Articles

Interaction Effect of Vesicular Arbuscular Mycorrhiza with Different Amendments on Increasing Phosphorus Uptake

Phosphorus (P), a essential element for all living organisms is often the most limiting nutrient in soil-plant systems. In order to increase the phosphorus content in plants and its uptake efficiency in alkaline soil, the following study was undertaken. The experiment was carried out in a factorial completely randomized block design with five treatment combinations viz., Control (no P), P alone @ 71.35 kg ha-1 , P with Farm Yard Manure (FYM) @ 12.5 t ha-1 , Enriched Farm Yard Manure (EFYM) (FYM @ 750 kg ha-1 enriched with recommended dose of SSP) and P with Humic acid @ 3 kg ha-1 . All the five treatments were tried with and without Vesicular Arbuscular Mycorrhiza (VAM) @ 5 kg ha-1 and the experiment was replicated four times. The phosphorus concentration in soil and plant samples were analysed. The available phosphorus status in soil showed a decreasing trend along the growth stages of maize but the application of P with FYM (25.04 kg ha-1 ) and as EFYM (24.57 kg ha-1 ) recorded significantly higher available P in all the stages. The plant P concentration also showed the decreasing trend along the crop growth stages and recorded the highest concentration in P with FYM and VAM treatment (0.19 %). The grain P uptake (0.14 g pot-1 ) and stover uptake (0.10 g pot-1 ) was also found to be higher in the application of P and FYM with VAM. The combined application of inorganic minerals (SSP @ 71.35 kg ha-1 ) along with organics (FYM @ 12.5 t ha-1 ) and bioinoculants (VAM @ 5 kg ha-1 ) can enhance the soil quality and health for the sustainable crop production.

Effect of Bio-fertilizers and Vesicular-arbuscular Mycorrhiza (VAM) on Growth, Yield and Economics of Rabi Groundnut (Arachis hypogaea) in Balasore District of Odisha

An on farm trial was conducted to evaluate the effect of Biofertilisers and VAM on growth, yield & economics of Groundnut production. The experiment was laid out in Randomized block design with three treatment combination replicated seven times. The experiment was conducted during the Rabi season of 2019-20 at Narayanpur village under Baliapal block in Balasore district of Odisha. Seven number of farmers were included in this trial. The results of the experiment revealed that integrated application of N-P2O5-K2O @ 20:40:40kg/ha + Seed treatment with Rhizobium@ 50g/kg of seed + Soil application of PSB@ 5kg/ha &VAM@ 10kg/ha at sowing recorded significantly maximum growth & yield attributes resulting 25.4% higher pod yield than sole application of N-P2O5-K2O @ 20:40:40kg/ha.

Induction of Systemic Resistance in Tomato (Solanum lycopersicom L.) Against Damping-off Disease by Using a Mixture of Mycorrhizae

Khrieba, M.I., M.F. Azmeh, W. Chouman, I. Ghazal, and A.K. Ali. 2021. Induction of Systemic Resistance in Tomato (Solanum lycopersicom L.) Against Damping-off Disease by Using a Mixture of Mycorrhizae. Arab Journal of Plant Protection, 39(1): 61-68. The effect of vesicular-arbuscular mycorrhiza (VAM) in improving the activity of the enzyme peroxidase and its role in controlling tomato damping-off caused by Pythium ultimum was studied in a pot experiment during the 2013 growing season. Five treatments were compared with a non-treated control (C): in treatment 1, soil was infested only with Pythium (Py), in treatment 2, soil was infested with mycorrhiza only (My), in treatment 3 soil was infested with Pythium and mycorrhiza at sowing (My+Py), in treatment 4, soil was infested with Pythium and two weeks after sowing with Mycorrhiza (Py-My) and in treatment 5, soil was infested with mycorrhiza and two weeks after sowing with Pythium (My-Py). The results showed that peroxidase concentration in plant tissues 14 days after seed germination in the My treatment (361.91 μmole/mg) significantly exceeded the other treatments. In the treatment where mycorrhiza was added before the pathogen 67 Arab J. Pl. Prot. Vol. 39, No. 1 (2021) peroxidase activity reached 183.73 μmole/mg, which was 41% significantly higher than the My+Py treatment in which the pathogen and mycorrhizal inoculant were added together at sowing (108.27 μmole/mg). The peroxidase concentration increased significantly 28 days after seed germination in the My treatment (687.52 μmole/mg) as compared with the Py treatment (10.52 μmole/mg). Results also showed that in the treatment My-Py, where the mycorrhyzal inoculum was added before the pathogen, peroxidase activity (458.27 μmole/mg) was significantly higher than in the treatment Py+My, when the pathogen was added simultaneously with the vesicular-arbuscular mycorrhizal inoculum (98.67 μmole/mg). Furthermore, results showed that 35 days after seed germination, the enzyme concentration was significantly higher in the My-Py treatment (763.39 μmole/mg) as compared with My+Py treatment (143.5 μmole/mg). Keywords: Vesicular-arbuscular mycorrhiza, VAM, Pythium ultimum, peroxidase, tomato, Syrian coast, induced resistance.

Vesicular Arbuscular Mycorrhiza Influences the Histo-Anatomic Characteristics of Vegetative Organs in Artemisia annua

Abstract Recent studies have shown that vesicular-arbuscular mycorrhizae stimulate plant growth in case of Artemisia annua plants. According to these studies mycorrhization can enhance plant height and biomasses, shoot branching and inter-nodal length, foliar glandular hair density, and nutrient status of shoots and leafs. Contradictory data were obtained in case of leaf chlorophyll content and photosynthetic rate. The effects of vesicular-arbuscular mycorrhizae on roots, shoots and leafs anatomy of A. annua have not been studied yet. The aim of this paper was to compare the microscopic characteristics of the vegetative organs from the Artemisia annua plants treated with vesicular-arbuscular mycorrhizae, with those from the control plants. Rhizophagus irregularis influenced the development of vascular tissues in root and stem of Artemisia plants by increasing their surface in the organs. Mycorrhization also reduced the percentage of lignification in the cortex of the root, increased the percentage of palisade parenchyma in leaf and had a positive effect on foliar glandular hair density. Further investigations are necessary to find out the role of these histo-anatomic alterations in the growth and development of Artemisia plants.

Effect of Vesicular Arbuscular Mycorrhiza on the Growth and the Characteristics of Rice Varieties in Rainfed Lowland Rice Cultivation

Effect of Vesicular Arbuscular Mycorrhiza on the Growth and the Characteristics of Rice Varieties in Rainfed Lowland Rice Cultivation

Interaction of Mesorhizobia, Vesicular Arbuscular Mycorrhiza and different Chickpea (Cicer arietinum L.) Genotypes for Nitrogen Fixing and Yield Attributing traits

Twenty genotypes of chickpea were evaluated to study the interaction of chickpea genotypes, mesorhizobial strains and vesicular arbuscular mycorrhiza for 14 nitrogen fixing and yield attributing traits viz. days to 50% flowering, days to maturity, plant height (cm), number of branches per plant, number of pods per plant, 100 seed weight (g), seed yield per plant (g), number of nodules per plant, nodule weight per plant (g), root dry weight per plant (g), shoot dry weight per plant (g), nitrogen content in shoot (%), nitrogen content in grain (%) and VAM infection(%). The analysis of variance revealed the existence of significant amount of genetic variability in the material for all the traits. All the genotypes were treated with three treatments separately (Mesorhizobium sp. Strain CH 1233 (S1); Mesorhizobium sp. Strain CH 810 (S2); vesicular arbuscular mycorrhiza (VAM) (Glomus fasiculatum) and one set was used as uninoculated control. These were grown separately following randomized block design with three replications in each treatment. Comparative analysis indicated the differences between the treatments and behaviour of the genotypes in different environments. In general S1 and VAM showed beneficial interaction for maximum number of traits for all the genotypes. The effect of VAM was the most apparent among treatments. On overall basis, genotypes viz. HC 3, HC 5, GL 94022, ICC 5003LN, HK 2, GNG 663 and BG 362 were observed to be better performing and responsive to bio inoculants having one or more superior traits. These genotypes performing better for specific traits can be used as parents in hybridization programme for improvement of that particular trait.

Effect of rhizobium, VAM and rock phosphate inoculation on growth and productivity and isolation of VAMF spores of Pisum sativum

Rhizobium, VAM and rock phosphate inoculation has a significant utilization in Pisum sativum.The present study was conducted to study the influence of rock phosphorus fertilization, Vesicular Arbuscular Mycorrhizae (VAM) and rhizobium inoculation on growth and yield parameters of Pisum sativum. The experiment was laid out in randomized complete block design during summer season at the Department of Botany University of Peshawar Pakistan. A composite soil sample was collected for analysis of soil for physical and chemical properties. Rock phosphorus fertilization, application along with AMF and rhizobium inoculation increased the growth parameters significantly. Inoculation under Phosphors deficient soil which have pivotal role in the mycorrhization, growth and productivity. Dual inoculation, Rhizobium and AMF resulted in an increase in grain yield respectively, over no inoculation in Pisum sativum. Maximum growth was observed where AMF along with rhizobium and rock phosphate inoculation were applied. It is concluded that Pisum sativum should preferably be grown with dual inoculation of VAM along with rhizobium and rock phosphate. And vesicular arbuscular mycorrhizal spores in the rhizospheric soils of Pisum sativum at three different stages,vegetative, flowering and fruiting highest spores density recorded at fruiting stage and increased with the age of plant and also effected by the treatment highest in dual inoculation as comapared to single inoculation.

The Effect of Arbuscular Vesicular Mycorrhizae on the Efficiency of Phosphate Absorption on the Growth and Production of Cayenne Pepper (Capsicum Frutescens L. )

This study aims to determine the effect of vesicular arbuscular mycorrhiza and phosphate fertilization on the growth and production of cayenne pepper (Capsicum frutescens L. ). Research conducted at the Greenhouse o f Faculty of Agriculture, University of Muhammadiyah Sidoarjo. Factorial experiment arranged in a completely randomized design (CRD) with repeat 4 times. The first factor: VA mycorrhizal (with and without mycorrhiza); the second factor: phosphate (0, 100, 200 and 300 kg TSP/Ha). The variables measured were plant height, number of leaves, stem diameter, number of flowers, fruit number, fruit weight, fresh weight of plants, phosphate uptake. Data were analyzed by ANOVA followed by Duncan test 5%. Mycorrhizal fungi and phosphate give significantly different interaction effects on plant height, stem diameter, plant fresh weight, and phosphate uptake of plants with mycorrhizal fungi combination VA and phosphate 300 kg/Ha which gives the highest yield. Mycorrhizal fungi significant effect in increasing plant height, number of leaves, stem diameter, number of flowers, number of fruits, fruit weight and wet weight of plants and plant phosphate uptake. Phosphate significant effect in increasing plant height, number of leaves, stem diameter, number of flowers, number of fruits, fruit weight and wet weight of plants and plant phosphate uptake. There is no difference between the effect of phosphate 100 kgTSP/Ha with 200 and 300 kg/Ha TSP in high regard detainees, number of leaves, stem diameter, number of relationship, the amount of fruit, fruit weight, and plant fresh weight.

English

A field experiment was carried out to assess the effects of vesicular arbuscular mycorrhiza (VAM), Organo-mineral fertilizer (OMF) and NPK (15:15:15), on the performance and post-harvest quality of sweet corn. The experiment was laid out in a split plot design with mycorrhiza as main plot and fertilizer combinations as treatments. VAM inocula were applied at a rate of 888.88 kg ha-1, OMF at 2000 kg ha-1 and NPK (15:15:15) at 400kg ha-1. Storability of the sweet corn was evaluated at open shelf (25-27°C), normal refrigeration (40°C) and deep freezing conditions (0°C). Results showed that there were significant differences (p <0.05) between mycorrhiza and non mycorrhiza. Across mycorrhiza treatment, the highest yields of free corn ears were obtained with the complementary use of OMF and NPK (15:15:15). Fertilizer application had significant effect on the storage life of sweet corn, however, sweet corn stored by freezing at 0°C had the best storage properties in terms of firmness, weight loss and disease incidence.   Key words: Vesicular arbuscular mycorrhiza; sweetcorn yield; Organo-mineral fertilizer.

Effects of Vesicular Arbuscular Mycorrhizae and Applied Phosphorus through Targeted Yield Precision Model on Root Morphology, Productivity, and Nutrient Dynamics in Soybean in an Acid Alfisol

A field experiment was conducted in a phosphorus (P)–deficient acidic Alfisol in northwestern Himalayas to study the effect of three vesicular arbuscular mycorrhizae (VAM) cultures [VAML, local VAM culture (Glomus mosseae) developed by CSK Himachal Pradesh Agricultural University, Palampur, India; VAMT, VAM culture (Glomus intraradices) developed by Centre for Mycorrhizal Research, The Energy and Resources Institute (TERI), New Delhi, India; and VAMI, VAM culture (Glomus mosseae) developed by Indian Agricultural Research Institute (IARI), New Delhi, India] on growth, productivity, and nutrient dynamics in rainfed soybean. Plant height, aboveground dry matter, root dry matter, total dry matter, root length, root weight density, Rhizobium root nodule count, root colonization, yield attributes, yield, and nutrient uptake of soybean increased consistently and significantly with increase in inorganic P levels from 25 to 75% of recommended P2O5 dose based on targeted yield precision model coupled with various VAM cultures. VAMT (Glomus intraradices) at each P level showed its superiority over VAMI and VAML. Sole application of any of the three VAM cultures produced similar growth and development parameters as well as grain yield (18.68 to 19.08 q ha−1) as produced through farmers’ practice (nitrogen at 20 kg ha−1), indicating that VAM has a vital role in root morphology and nutrient dynamics in a soil–plant system, though significantly greater productivity was obtained with 100% of the recommended P2O5 dose based on soil-test crop response (STCR) precision model without VAM inoculation. Targeted grain yield of soybean (25 q ha−1) was achievable with 75% of the recommended P2O5 dose applied with any of the three VAM fungi cultures without impairing soil fertility, thereby indicating that VAM fungi can save about 25% P fertilizer in soybean in P-deficient acidic Alfisols of northwestern Himalayas.

Investigation of the effects of Vesicular Arbuscular Mycorrhiza on mineral nutrition and growth of Carthamus tinctorius under salt stress conditions

Salt stress is considered as one of the most important abiotic factors limiting plant growth and yield in many areas of the world. It has been shown that Vesicular Arbuscular Mycorrhizal Fungi (AMF) can alleviate this deficiency. The effects of AMF inoculation on growth variables and mineral nutrition of Carthamus tinctorius L. under salt stress condition were studied. Plants were grown in a sterilized, low-P sandy soil with Glomus etunicatum inoculum (10–12 spore/g soil) in a greenhouse. RLC (Root Length Colonized) percent was higher in control plants than treated ones with different salt concentrations. Shoot and root weights, height, the number of leaves, the number of lateral branches, and also leaf area of mycorrhizal (M) plants were higher than nonmycorrhizal (NM) ones in both controlled and salt-treated plants. P, Zn, Fe, Ca, K, Cu, and N contents in M plants were higher than in NM plants in control, low and medium salinity conditions, but Na content was lower in aerial parts of the M plants. The results showed a higher tolerance of inoculated M plants toward salt stress and their better growth.

Effects of vesicular-arbuscular mycorrhiza on the protective system in strawberry leaves under drought stress

Vesicular-arbuscular mycorrhiza (VAM) plays a very important role in improving plant drought resistance abilities. A pot experiment was conducted during the 2008–2009 strawberry growing season in the greenhouse at Baoding, Hebei Province, China, aiming at exploring the influence of VAM on the drought tolerance of strawberry and elucidating the interaction mechanism. Three treatments were designed in our study, including routine water supply treatment (CK-WW), drought stress treatment with VAM fungi (GM-DS), and drought stress treatment without VAM fungi (CK-DS). Four indicators of each treatment were measured, respectively, including protective enzyme activity, pigment content, plasma membrane, and osmoregulation. The results showed that the treatment inoculated VAM fungi can increase the protective enzyme activity, osmoregulation, and antioxidant capacity membranaceous, especially the activity of catalase (CAT) and ascorbate peroxidase (APX). Inoculating strawberry plants with VAM fungi under drought stress could also lead to increasing the content of leaf pigment, accelerating the accumulation of free praline and soluble protein, improving the transport speed of soluble sugar, restraining the decomposition of chlorophyll, decreasing the malondialdehyde content and plasma membrane conductivity, and improving the H+-ATPase activity.

Thidiazuron induced high frequency shoot organogenesis in callus from Kigelia pinnata L.

An efficient regeneration system was developed for Kigelia pinnata L., a multipurpose tree belonging to the family Bignoniaceae. The nodal segments were cultured in vitro, and the optimum concentrations of plant growth regulators for callus induction were determined. The friable organogenic calli were derived from the basal cut end of the nodal segments. The highest yield of morphogenic callus (100%) was observed when nodal segments were cul- tured on Murashige and Skoog (MS) medium supplemented with 3 µM 2,4 dichlorophenoxyacetic acid (2, 4-D). The morphogenic callus maintained high regeneration during the first four subcultures in the callus induction medium. The maximum shoots (28/culture) were regenerated at the highest frequency of 100% when 3 µM thidiazuron (N-phenyl N' 1,2,3-thidiazol-5-yl urea) (TDZ) and 0.5 µM naphthaleneacetic acid (NAA) were added to MS medium. The emergence of multiple shoots from the calli was histologically documented. The regenerated shoots showed maxi- mum rooting on ½ MS medium containing 4 µM indole-3- butyric acid (IBA). The effect of vesicular arbuscular mycorrhizae (VAM) association in averting the transplantation shock was tested and proved to be highly beneficial, giving a 100% survival rate after 60 d of transplantation. This efficient plant regeneration system provides a founda- tion for generating transgenic plants of this multipurpose tree.

Combined effects of earthworms and vesicular-arbuscular mycorrhizas on plant and aphid performance.

• Vesicular-arbuscular mycorrhiza (VAM) and earthworms are known to affect plant and herbivore performance. However, surprisingly few studies have investigated their interactions. • In a glasshouse experiment we investigated the effects of earthworms (Aporrectodea caliginosa) and VAM (Glomus intraradices) on the growth and chemistry of Plantago lanceolata and the performance of aphids (Myzus persicae). • Earthworms did not affect VAM root colonization. Earthworms enhanced shoot biomass, and VAM reduced root biomass. VAM increased plant phosphorus content, but reduced the total amount of N in leaves. Earthworms led to a preferential uptake of soil N compared with 15 N from the added grass residues in the absence of VAM. Earthworm presence reduced the concentration of catalpol. Earthworms and VAM combined accelerated the development of M. persicae, while the development tended to be delayed when only VAM or earthworms were present. • We suggest that earthworms promote plant growth by enhancing soil N availability and may affect herbivores by influencing concentrations of secondary metabolites. VAM enhances the P uptake of plants, but presumably competes with plant roots for N.

Effect of vesicular arbuscular mycorrhizae and phosphate- solubilizing bacteria on growth, yield and phosphorus uptake by wheat (%ticum aestivum) and chickpea (Cicer arietinum)

A field experiment was conducted during 1997-98 and 1998-99 to study the effect of vesicular arbuscular mycorrhizae (VAM) and phosphate-solubilizing bacteria (PSB) on growth, yield and phosphorus uptake by wheat (Triticum aestivum L. emend. Fiori & Paol.) and chickpea (Cicer arietinum L.). Application of phosphorus did exhibit perceptible influence on yield of the crops. Both biofertilizer and phosphorus nutrition interaction showed significant influence on growth and phosphorus uptake by wheat and chickpea compared with either of the components applied separately. Among the biofertilizers, Pseudomonas striata registered the highest grain yield in both crops at both levels of phosphorus, closely followed by Glomus fasciculatum. Among the VAM fungi, Glomus fasciculatum had positive influence on yield and phosphorus uptake whereas it was lacking in Glomus macrocarpum.

Effects of mycorrhizae and phosphorus on growth and nutrient uptake of millet, cowpea and sorghum on a West African soil

Despite numerous reports on the positive effects of vesicular arbuscular mycorrhizae (VAM) on plant growth in temperate soils, surprisingly little data exist on the importance of VAM for crop growth on acid sandy soils of West Africa. A pot experiment conducted with local genotypes of pearl millet (Pennisetum glaucum L.), sorghum (Sorghum bicolor L. Moench) and cowpea (Vigna unguiculata) with and without phosphorus (P) application in a sterilized sandy soil from a farmer's field in Niger showed large growth-enhancing effects of VAM. Phosphorus application led to 18- and 24-fold increases in pearl millet root and shoot dry matter independently of VAM, whereas the shoot and root dry matter of sorghum and cowpea depended largely on the interaction between P application and VAM. With P, VAM increased total uptake of P, K, Ca, Mg and Zn by 2·5- to 6-fold in sorghum and cowpea. On severely P deficient West African soils P application can lead to large increases in early root growth, a prerequisite for early mycorrhizal infection and a subsequent significant contribution of VAM to enhanced plant growth and nutrient uptake.

The role of mycorrhizal fungi and microsites in primary succession on Mount St. Helens

This study was designed to examine the role of vesicular-arbuscular mycorrhizae (VAM) and microsites on the growth of pioneer species. Flat, rill, near-rock, and dead lupine microsites were created in plots in barren areas of the Pumice Plain of Mount St. Helens. VAM propagules were added to the soil in half of the plots. Six pioneer species were planted into both VAM and non-VAM inoculated microsites. Plants in dead lupine microsites were greater in biomass than those in flat, rill, and near-rock microsites. Significant effects of VAM on plant biomass did not occur. Microsites continue to be important to plant colonization on the Pumice Plain, but VAM do not yet appear to play an important role. This may be due to limited nutrient availability and the facultatively mycotrophic nature of the colonizing plant species. It is unlikely that VAM play an important role in successional processes in newly emplaced nutrient-poor surfaces.

Vesicular arbuscular mycorrhizae-mediated uptake and translocation of P and Zn by wheat in a calcareous soil

Vesicular-arbuscular mycorrhizae (VAM) have been credited with improving the growth and mineral nutrition of many host plants but these effects are moderated by soil factors and nutrient balance. We investigated the combined effects of VAM, zinc and phosphorus application on the growth, uptake and translocation of nutrients in wheat using a calcareous soil marginal in P and Zn. Wheat was grown in a growth chamber under various combinations of VAM, P and Zn with measurements done at heading stage and maturity. Vegetative dry matter accumulation was increased by P additions and reduced by VAM infection. Both P addition and VAM infection increased grain yield. Zinc concentration and uptake were generally reduced by P additions and VAM infection. There was an absence of antagonistic effects of Zn additions on P concentration and uptake. In contrast, VAM infection had both positive and negative effects on P uptake depending on the growth stage and translocation of nutrients. We observed that in calcareous soils where the Zn and P fertilizer combinations were adequate for growth, the role of VAM in enhancing the translocation of Zn and P from root and straw to grain is beneficial towards seed set and yield. Key words: VA mycorrhizae, P and Zn fertilization, calcareous soil, wheat, yield, nutrient acquisition, translocation

165 VESICULAR-ARBUSCULAR MYCORRHIZAE DECREASE DAYS TO FLOWERING AND INCREASE INFLORESCENCE NUMBER OF GERANIUM `SPRINTER SCARLET' GROWN IN THREE SOILLESS MEDIA.

The effects of vesicular-arbuscular mycorrhizae (VAM) on the growth and flowering of Geranium `Sprinter Scarlet' in three greenhouse soilless media were investigated. All media proved to be well suited for geranium growth and VAM had no significant effect on most vegetative parameters. However, VAM significantly reduced the number of days to flowering of plants grown in Mycori-Mix and Sunshine Aggregate #4 by 6.4 and 6.6 days respectively. Plants grown in Mycori-Mix with VAM flowered 99.4 days after sowing, significantly sooner than those grown in the other media with VAM. Mycorrhizal plants in Mycori-Mix and Metro Mix had a greater number of lateral branches >5 cm in length than non-mycorrhizal in the same media. Regardless of VAM treatment, plants grown in Mycori-Mix had a greater number of visible inflorescences at harvest than the other two media.

Effect of vesicular-arbuscular mycorrhizae on seedling growth of four tree species from the tropical deciduous forest in Mexico

The influence of vesicular-arbuscular mycorrhizae on the growth of seedlings of Caesalpinia eriostachys, Cordia alliodora, Ipomoea wolcottiana and Pithecellobium mangense was investigated in a greenhouse experiment conducted at the Biological Station of Chamela on the Pacific coast of Mexico. Dry biomass production, relative growth rate, root/shoot ratio and mycorrhizal dependency were quantified for 75-day-old seedlings. With the exception of the pioneer species I. wolcottiana, mycorrhizal infection resulted in increases in biomass production, relative growth rate and leaf area. The root/shoot ratios attained for the species, however, did not show a consistent trend with infection. Nevertheless, all species had root/shoot ratios below 1 with infection and only one, Cordia alliodora, had a ratio greater than 1 without infection. The two late successional species from the mature part of the forest, Caesalpinia eriostachys and P. mangense, showed a larger mycorrhizal dependency than the two associated with disturbed environments.