Mycorrhizal Dependency Research Articles

Mycorrhizal dependence of citrus rootstock

Abstract Plant growth promoting microorganisms, such as mycorrhizal fungi, have been widely used in agriculture because they help plants in the absorption of nutrients and water, influencing their growth. The objective of this work was to verify the effect of the mycorrhizal association of Glomus clarum and Glomus etunicatum on the initial growth of the rootstocks Rangpur lime, Swingle citrumelo and Sunki mandarin. The experimental design was completely randomized with a 3 x 4 factorial arrangement, with five replications, corresponding to three rootstocks, four managements: mineral fertilization, inoculation with G. clarum (IGC), inoculation with G. etunicatum (IGE) and Control. The seedlings were produced in greenhouse, using as substrate the vermicompost earthworm, distributed in polyethylene bags, depositing three seeds of each rootstock / bag. The inoculation with mycorrhizal fungi was carried out at the time of sowing (45 spores of each species / bag). The mineral fertilization was divided into two phases: phosphorus application before sowing (40g of single superphosphate / bag); nitrogen application (1.7 g dissolved in 40 ml of water), divided in eight applications of 5 ml of the solution, via irrigation water, manually and weekly; and micronutrients (B, Cu, Fe, Mn and Zn), sprayed manually every two weeks. The following parameters were evaluated: height, stem diameter, number of leaves, shoot dry mass, colonization and mycorrhizal dependence. There was a significant interaction between the rootstocks and treatments applied in this study for most of the evaluated variables. Rangpur lime and Swingle citrumelo obtained higher height and the management that conferred higher height to the rootstocks was the mineral fertilization and IGE. The largest diameter of the stem was reached by Swingle citrumelo and the management that provided the largest diameter was the inoculation with G. etunicatum. Rangpur lime presented moderate mycorrhizal dependence for G. clarum and marginal for G. etunicatum. Mycorrhizal colonization did not show a significant interaction between rootstocks and the management with inoculation. The mycorrhizal association of G. clarum and G. etunicatum was not presented as the best management for the growth of Rangpur lime, Swingle citrumelo and Sunki mandarin, when compared to the mineral fertilization. However, the inoculation of mycorrhizal fungi provided a positive effect on the uptake of some nutrients by the rootstocks, especially K, Mg, N and P.

Species composition of native arbuscular mycorrhizal fungal consortia influences growth and nutrition of poblano pepper plants (Capsicum annuum L.)

The influence of agronomic management of poblano pepper crops on the composition and effectiveness of arbuscular mycorrhizal fungi (AMF) was determined based on growth promotion and nutrition of Capsicum annuum plants. Mycorrhizal colonization, spore number, and AMF-species composition in the rhizosphere soil of C. annuum were determined from six agroecosystems with different agronomic management: a) San Martinito (SM) with little management, b) Santa María Zacatepec (SMZ), Juárez Coronaco I and II (JCI and JCII) with moderate management, and c) San Mateo Capultitlan I and II (SMCI and SMCII) with intense management. From each agroecosystem an AMF consortium was obtained for evaluating its effectiveness on plant growth. A completely randomized design with seven treatments and 10 replicates was set. Plant growth parameters and leaf content (N, P, and K) were determined after 90 days of AMF-inoculation; in addition, AMF colonization, spore number, and mycorrhizal dependence were determined. The AMF-species composition in consortia from agroecosystems with low and moderate management was different from that obtained from agroecosystems with intensive management. The SMZ consortium, isolated from the agroecosystem with moderate management, significantly increased the stem diameter, plant height, and leaf area; in contrast, the SMCI consortium, isolated from the agroecosystem with intense management, showed the lowest values in all growth parameters. All AMF-consortia increased the leaf content of N and K; however, only the SMZ consortium had significant effects on P content. Plants inoculated with the SMCII and SMZ consortia showed highest mycorrhizal dependence for shoot biomass and nutrient content, respectively. The isolation and utilization of native AMF consortia may promote the growth and nutrition of poblano pepper plants, and be an important biological component for sustainable pepper cropping.

Do the impacts of alien invasive plants differ from expansive native ones? An experimental study on arbuscular mycorrhizal fungi communities

No studies have compared so far the effects of alien invasive and expansive native (widespread, mono-dominant) plants on arbuscular mycorrhizal fungi (AMF). Four global or European most successful invaders (Impatiens glandulifera, Reynoutria japonica, Rudbeckia laciniata, Solidago gigantea) and two expansive plants native to Europe (Artemisia vulgaris, Phalaris arundinacea) were grown in pots to elucidate the magnitude and direction of changes in AMF abundance, species richness, and species composition in soils from under multispecies native vegetation. In a second stage, the effects of these changes on a native plant, Plantago lanceolata, were assessed. Plant species identity had larger impact on AMF abundance, species richness, and species composition as well as on P. lanceolata than origin of the species (alien vs. native). This could be due to the character of AMF relationships with the plants, i.e., their mycorrhizal status and dependency on AMF. However, the alterations induced by the plant species in soil chemical properties rather than in AMF community were the major drivers of differences in shoot mass and photosynthetic performance of P. lanceolata. We determined that the plants produced species-specific effects on soil properties that, in turn, resulted in species-specific soil feedbacks on the native plant. These effects were not consistent within groups of invaders or natives.

Biological inoculation and organic amendments as strategies to improve ebony (Caesalpinia ebano) tree-seedling growth at the nursery

Se estableció un experimento con el objetivo de evaluar el efecto de la adición individual y combinada de enmiendas orgánicas e inoculantes microbianos sobre el crecimiento en vivero de la especie forestal ébano (Caesalpilinia ebano). Se utilizó un suelo superficial (0-20 cm) como soporte de crecimiento, este se transfirió a bolsas plásticas (2 kg/bolsa) y se adicionaron tres tipos de enmiendas orgánicas compostadas (estiércol de animales domésticos –perros y gatos (P)-, residuos vegetales generados en la ciudad a partir de talas, podas y rocerías (RV) y biosólidos de la planta de tratamientos de aguas residuales (B)) en dos proporciones volumétricas (20 y 33%) y la inoculación conjunta del hongo micorrizal Rhizoglomus fasciculatum y el hongo solubilizador de minerales Mortierella sp. Se utilizó un control no fertilizado. El diseño fue completamente al azar y cada tratamiento tuvo 12 repeticiones. Los resultados indican que las enmiendas orgánicas promovieron significativamente el crecimiento vegetal. Sin embargo, los efectos dependieron del tipo y la dosis empleada, a favor de los RV. Por otro lado, la inoculación con los microorganismos no tuvo efecto sobre el crecimiento de las plantas. Los efectos se explican en función del mejoramiento de la disponibilidad de nutrientes con las enmiendas y de la presumible baja dependencia micorrizal del ébano. Este trabajo soporta el uso alternativo de enmiendas orgánicas generadas en la ciudad para promover la nutrición y el crecimiento de plantas de silvicultura urbana.

Under sterilized and non-sterilized soil conditions, mycorrhizal dependency in citrus plants depends on phosphorus fertilization rather than zinc application

Under sterilized and non-sterilized soil conditions, mycorrhizal dependency in citrus plants depends on phosphorus fertilization rather than zinc application

Effects of arbuscular mycorrhizal fungi on growth and nitrogen uptake of Chrysanthemum morifolium under salt stress.

Soil salinity is a common and serious environmental problem worldwide. Arbuscular mycorrhizal fungi (AMF) are considered as bio-ameliorators of soil salinity tolerance in plants. However, few studies have addressed the possible benefits of AMF inoculation for medicinal plants under saline conditions. In this study, we examined the effects of colonization with two AMF, Funneliformis mosseae and Diversispora versiformis, alone and in combination, on the growth and nutrient uptake of the medicinal plant Chrysanthemum morifolium (Hangbaiju) in a greenhouse salt stress experiment. After 6 weeks of a non-saline pretreatment, Hangbaiju plants with and without AMF were grown for five months under salinity levels that were achieved using 0, 50 and 200 mM NaCl. Root length, shoot and root dry weight, total dry weight, and root N concentration were higher in the mycorrhizal plants than in the non-mycorrhizal plants under conditions of moderate salinity, especially with D. versiformis colonization. As salinity increased, mycorrhizal colonization and mycorrhizal dependence decreased. The enhancement of root N uptake is probably the main mechanism underlying salt tolerance in mycorrhizal plants. These results suggest that the symbiotic associations between the fungus D. versiformis and C. morifolium plants may be useful in biotechnological practice.

A differential capacity of arbuscular mycorrhizal fungal colonization under well-watered conditions and its relationship with drought stress mitigation in unimproved vs. improved soybean genotypes

Modern breeding programs may cause a reduction in plant responsiveness to arbuscular mycorrhizal (AM) fungi. In this study, we tested the hypothesis that responses such as higher arbuscule formation and mycorrhizal dependency (MD) in unimproved soybean genotypes than in improved genotypes is related to drought stress tolerance caused by enhanced growth parameters and oxidative stress regulation. Firstly, four unimproved and four improved soybean genotypes were compared under well-watered conditions. After 20 days, all of the unimproved soybean genotypes showed increased arbuscule formation, as well as a positive and higher MD index in foliar mineral nutrient and growth parameters compared with the four improved genotypes. Secondly, tolerance to drought stress was evaluated in the two improved soybean genotypes and the two unimproved genotypes selected for the most contrasting response to arbuscule formation under well-watered conditions. After 20 days of 30% of field capacity, arbuscule formation was higher in the unimproved than improved genotypes. Mycorrhizal dependency evaluated as leaf area as well as shoot and root dry mass were highest in the unimproved AM genotypes. Moreover, levels of malondiadehide were lower and proline was higher in the unimproved rather than the improved genotypes. The potential capacity of arbuscule formation is discussed as a selection criterion to identify improved soybean genotypes with increased efficiency under well-watered conditions and an enhanced capacity to relieve drought stress.

Can Cd translocation in Oryza sativa L. be attenuated by arbuscular mycorrhizal fungi in the presence of EDTA?

Arbuscular mycorrhizal (AM) fungi play an important role in plant tolerance of heavy metal contamination. In this study, a pot experiment was conducted to illustrate the effects of the two AM fungi species Funneliformis mosseae (Fm) and Rhizophagus irregularis (Ri) on plant growth of Oryza sativa L. either with or without ethylenediamine tetraacetate (EDTA) addition and during exposure to five Cd concentrations (in the range of 0-5mgkg-1). The results showed that Fm inoculation achieved greater mycorrhizal colonization and mycorrhizal dependency indexes than Ri inoculation. In addition, the effects of AM fungi on Cd biosorption and translocation in rice were also investigated in the presence of EDTA. Despite cooperative adsorption, the Freundlich isotherm could describe the biosorption effects of Cd on rice roots regardless of AM fungi inoculation or EDTA addition. Cd concentrations in mycorrhizal roots increased but decreased in mycorrhizal shoots in contrast to the control treatment. Although EDTA addition negatively inhibited the uptake of Cd to mycorrhizal shoots, lower translocation factor (TF) and bioconcentration factor (BCF) were still observed in treatments with EDTA compared to control treatment. Our findings suggest that Ri and Fm inoculation enhanced Cd immobilization in the roots, thus preventing Cd entry into the food chain during exposure to low and high Cd stress, respectively.

Combination of plastic film mulching and AMF inoculation promotes maize growth, yield and water use efficiency in the semiarid region of Northwest China

Plastic film mulching (PFM) plays a critical role in improving crop production and sustainable development of agroecosystem in semiarid agriculture. Arbuscular mycorrhizal fungi (AMF) can form a mutualistic symbiosis with the vast majority of plant roots and have been shown to contribute to host growth in harsh conditions. Yet, whether the integrated application of PFM and AMF inoculation have an interactive effect on crop growth and production in semiarid regions with poor soil nutrients and water shortage has received rather less attention. Therefore, we performed a two-year field study to investigate the effects of PFM and AMF inoculation on spring maize growth, yield and water use efficiency (WUE). Four treatments, including non-mulching and non-AMF inoculation (CK), plastic film mulching (PFM), arbuscular mycorrhizal fungi inoculation (AMF) and combination of plastic film mulching and arbuscular mycorrhizal fungi inoculation (PAMF), were compared in 2014 and 2015 at Shenmu Country on the semiarid Loess Plateau of Northwest China. Our results indicated that AMF inoculation contributed to increased plant biomass and height, although its effectiveness was lower than PFM alone or combined practice. Compared with the non-mulched control (CK), the mulched treatments significantly increased the average soil water content by 43.2% at the depth of 0–60 cm in 2014 and by 30.3% at the depth of 0–30 cm in 2015. The combination of PFM and AMF inoculation had the greatest soil water content at different soil depths in both years. AMF inoculation significantly improved root mycorrhizal colonization and external hyphal length in both years. Meanwhile, mycorrhizal plants under PFM had significantly greater root tip number and surface area when compared with the control. PAMF treatment had the highest yield and WUE among all treatments. Compared with the CK, PAMF treatment increased the yield and WUE by55.6% and 43.1% in 2014 and by 39.3% and 45.6% in 2015, respectively. Moreover, the mycorrhizal dependency of maize yield was more notable in mycorrhizal plants grown in mulched soils than in bare soils. In conclusion, the combined application of PFM and AMF inoculation is an effective and favorable agricultural practice in nutrition-deficiency soil in semiarid regions of China because of improved root morphological traits and enhanced topsoil water content that increase crop productivity.

Crescimento inicial e absorção de fósforo e nitrogênio de Enterolobium contortisiliquum inoculada com fungos micorrízicos arbusculares

Enterolobium contortisiliquum is a leguminous tree that associates by symbiosis with arbuscular mycorrhizal fungi (AMF) and can be used to recover degraded areas. Therefore, the aim of this work was to evaluate the effects of AMF inoculation, supply of phosphorus (P), and rate of nitrogen (N) and P absorption in E. contortisiliquum. The variables were analyzed into randomized blocks with factorial design 5 x 3, in which the factors were levels of P (0, 50, 100, 200, and 400 mg kg-1), and inoculation with AMF (Gigaspora margarita and native population in soil), or non-inoculation (control treatment), with four repetitions in each treatment. The highest mycorrhizal colonization (35%) occurred in seedlings inoculated with G. margarita. Plants inoculated with G. margarita and under P supply of 0 and 50 mg kg-1 exhibited increase in height of 19.5% and 7.4%, respectively, compared to the control treatment. P levels in aerial part of plants inoculated with G. margarita, under levels of 0, 50, 100 and 400 mg kg-1of P presented high increment of 198%, 108%, 181% and 106%, respectively, compared to the control. The control treatment, without any P supply, seedlings inoculated with G. margarita exhibited high colonization efficiency (34.89%) and high mycorrhizal dependence (25.53%).

Effects of arbuscular mycorrhizal fungi on the growth of two turfgrasses grown under greenhouse conditions

ABSTRACT The need for salinity resistance in turfgrass is increasing because of the enhanced use of effluent and other low-quality water for turfgrass irrigation. Although most turfgrasses form an arbuscular mycorrhizal fungus (AMF) symbiosis, there is little information on the mycorrhization of turfgrass species. Therefore, the aim of this study was to determine the effects of three AMF species, Glomus intraradices Schenck & Smith, Glomus etunicatum Becker & Gerdemann, and Glomus deserticola Trappe & John, and a mixture thereof on the growth, productivity, and nutrient uptake of two species of cool-season turfgrasses, Challenger Kentucky bluegrass (Poa pratensis L.) and Arid tall fescue (Festuca arundinacea Schreb.), and to relate the effects to colonization of the roots by mycorrhiza to assess the dependency of the plants (mycorrhizal dependency [MD]). Following the experimental period (4 months) and measurements, the mycorrhizal inoculated plants had significantly greater biomass production compared to that of non-inoculated plants. MD and shoot mineral contents (particularly P) differed among turfgrass hosting AMF, and the highest value (13%) occurred for P. pratensis and F. arundinacea seedlings colonized with G. intraradices and G. deserticola, respectively. The P content was highest for the F. arundinacea/mixed AMF combination compared to other treatments. We confirmed that mycorrhizal inoculation (P. pratensis/G. intraradices and F. arundinacea/mixed AMF combinations) enhanced plant productivity and nutrient uptake (especially P) even under non-optimum conditions.

Association and mycorrhizal dependency in Jatropha curcas L. seedlings under salt stress

ABSTRACT The cultivation of Jatropha curcas L. for biodiesel production is possible in salinized areas; however, biomass production is limited in these soils. Arbuscular mycorrhizal fungi (AMF) are a promising alternative for bioremediation in salinized soils. Yet, salinity also affects the AMF at the time of colonization and, in this case, the symbiosis is not always established. Therefore, the aim of this study was to test the hypotheses that three AMF species commonly found in saline soils are associated with J. curcas and if seedlings previously inoculated with these AMF are more tolerant to salt stress. Two trials were performed: the first one was carried out in a completely randomized design with five treatments (control, Rhizophagus intraradices, Gigaspora albida, Claroideoglomus etunicatum, and the three species together) and six repetitions to investigate the formation of symbiosis among species; and the second trial was carried out in randomized blocks in a 4 × 2 factorial scheme (2, 5, 8, and 10 dS m-1, with and without mycorrhizae) with eight repetitions to verify the development and mycorrhizal dependency (MD) of the seedlings previously inoculated, in salinized environment. The three species of AMF are associated with J. curcas both alone and together. Mycorrhizal dependency increased with salinity, indicating that J. curcas is a facultative species. The pre-colonized seedlings with AMF are an alternative to the establishment of J. curcas in salinized soils.

Strong indirect herbicide effects on mycorrhizal associations through plant community shifts and secondary invasions.

Million of acres of U.S. wildlands are sprayed with herbicides to control invasive species, but relatively little is known about non-target effects of herbicide use. We combined greenhouse, field, and laboratory experiments involving the invasive forb spotted knapweed (Centaurea stoebe) and native bunchgrasses to assess direct and indirect effects of the forb-specific herbicide picloram on arbuscular mycorrhizal fungi (AMF), which are beneficial soil fungi that colonize most plants. Picloram had no effect on bunchgrass viability and their associated AMF in the greenhouse, but killed spotted knapweed and reduced AMF colonization of a subsequent host grown. Results were similar in the field where AMF abundance in bunchgrass-dominated plots was unaffected by herbicides one year after spraying based on 16:1ω5 phospholipid fatty acid (PLFA) and neutral lipid fatty acid (NLFA) concentrations. In spotted-knapweed-dominated plots, however, picloram application shifted dominance from spotted knapweed, a good AMF host, to bulbous bluegrass (Poa bulbosa), a poor AMF host. This coincided with a 63% reduction in soil 16:1ω5 NLFA concentrations but no reduction of 16:1ω5 PLFA. Because 16:1ω5 NLFA quantifies AMF storage lipids and 16:1ω5 PLFA occurs in AMF membrane lipids, we speculate that the herbicide-mediated reduction in host quality reduced fungal carbon storage, but not necessarily fungal abundance after one year in the field. Overall, in greenhouse and field experiments, AMF were only affected when picloram altered host quantity and quality. This apparent lack of direct effect was supported by our in-vitro trial where picloram applied to AMF mycelia did not reduce fungal biomass and viability. We show that the herbicide picloram can have profound, indirect effects on AMF within one year. Depending on herbicide-mediated shifts in host quality, rapid interventions may be necessary post herbicide applications to prevent loss of AMF abundance. Future research should assess consequences of these potential shifts for the restoration of native plants that differ in mycorrhizal dependency.

Mycorrhizal dependency and growth response of Gliricidia sepium (Jacq.) Kunth ex Walp. under saline condition

In pursuit of salinity-mycorrhiza interaction, a pot experiment was conducted to determine the dependence of Gliricidia sepium on arbuscular mycorrhizal association under salinity stress, which was imposed using different concentrations of sodium chloride solutions. The present study revealed that arbuscular mycorrhizal fungus; Rhizophagus fasciculatus significantly increased growth and biomass of G. sepium plants under saline condition. G. sepium showed a high degree of dependence on mycorrhizal symbiosis under saline as compared to non-saline condition. Under non-saline condition (SS0), G. sepium plants exhibited 23.9% dependence on R. fasciculatus, which increased with increase in the levels of salinity. At SS3 level, G. sepium plants showed 46.6% mycorrhizal dependency followed by SS2 and SS1 levels of salinity. However, there was no significant difference between mycorrhizal dependency of G. sepium at SS1 and SS2 levels of salinity. Improved growth of G. sepium under salinity stress revealed R. fasciculatus a promising inoculant for the reclamation of degraded saline soils.

Transfer of Nickel from Polluted Soil to Pisum sativum L. and Raphanus sativus L. under Composted Green Amendment and Native Soil Microbes

Abstract The effect of compost, inoculation with native soil microbes and their residual effects on bioavailability of nickel by peas (Pisum sativum L.) and radish (Raphanus sativus L.) grown on polluted soil were investigated in pot experiments. Plants were amendment with different compost levels (0, 0.2, 0.4, 0.6% of soil dry weight) and inoculated with different native soil microbes (4 fungal species, one bacterial species, 4 species of arbuscular mycorrhizal fungi) isolated from the polluted soil under study. Significant increases in the biomass of pea and radish plants were observed as a result of amendment application and their residual effects. The mycorrhizal dependency (MD) of pea plants was lower than of radish plants. The highest reductions of Ni levels in both plants were observed by the simultaneous applications of compost with microbes or mycorrhizal fungi to polluted soils. Soil pH increased significantly (p < 0.05) as a result of applying native microbes especially with arbuscular mycorrhizal fungi (AMF) alone or combined with compost. The DTPA extractability of soil Ni was significantly decreased with increasing soil pH (p < 0.05). The minimum transfer factor of Ni from polluted soil were 0.067 and 0.089 for pea and radish plants, respectively which were attained as a result of applying compost (0.6% of soil weight) inoculated with mycorrhizal fungi. From the results, we can conclude that the use of compost and native soil microbes as a soil remediate could be an effective strategy for soil remediation.

Responses of wheat plants to interactions of 24-epibrassinolide and Glomus mosseae in saline condition.

This study was designed to investigate the possible effects of 24-Epibrassinolide (BR), arbuscular mycorrhizal (AM) fungus, Glomus mosseae, singularly and collectively under salt stress in wheat (Triticum aestivum L.) plants. After foliar spraying of mycorrhizal and non-mycorrhizal plants by 5µM epibrassinolide (24-Epi), they were treated with 0 and 150mM NaCl for 2weeks and then harvested. The results showed interactions of G. mosseae and 24-Epi could alleviate the adverse effects of salinity by improving relative water content (RWC) of leaves (62%), relative growth rate (40.74%), shoot fresh weights (39.83%) and shoot phosphorous content (63.93%), stimulating leaf enzymatic antioxidant activities including catalase (2.24 fold) and ascorbate peroxidase (2.18 fold) as well as malondialdehyde (36.17%) and H2O2 concentrations (49.74%) as compared to those of NaCl treatments. Moreover, mycorrhizal dependency of root dry weight (2%) and phosphorus concentration (0.4%) increased with AM infection and 24-Epi application under saline condition. Leaf RWC, also, negatively correlated with membrane electrolyte leakage. Furthermore, the greatest mitigating effects were observed in mycorrhizal plants subjected to NaCl and 24-Epi. This study indicated that 24-Epi application and AM fungi may synergistically mitigate harmful impacts of salinity in wheat plants.

Worm castings-based growing media with biochar and arbuscular mycorrhizal fungi for producing organic tomato (Solanum lycopersicum L.) in greenhouse.

Organic vegetable production has specific research and innovation requirements which are not shared by other parts of the food and farming sector. A pot experiment was conducted to investigate the interactive effects of few permitted organic inputs such as arbuscular mycorrhizal fungi, biochar, and different ratios of peat:worm casting on tomato (Solanum lycopersicum L.) growth, mycorrhizal dependency, biomass production, fruit yield, and soil respiration. The experimental design was a factorial arrangement based on completely randomized design with three replicates. Factors included worm casting at three levels (0, 15 and, 30% of the media volume), organic peat-based potting soil at three levels (70, 85, and 100% of the media volume), two Glomus intraradices treatments (inoculated at sowing or un-inoculated), and two biochar levels (10% of total weight of the media or unlamented). Results indicated that worm casting × peat combination significantly affected all measured traits except for the number of fruits in plant and mycorrhizal dependency. Mycorrhizal symbiosis had a significant effect only on shoot dry weight and mycorrhizal dependency. Moreover, biochar application significantly affected shoot dry weight, stem diameter and carbon mineralization. Among the different ratios of worm casting and peat in the growing media, 15% worm casting × 85% peat formed the most suitable medium condition for plants and 100% peat without worm casting was the least suitable. The highest fruit fresh weight (228.7 g/plant) was achieved in 15% worm casting × 85% peat and the lowest fruit fresh weight (175.1 g/plant) was achieved in 100 peat treatment.

Biocontrol of Sclerotium rolfsii in Groundnut by Using Microbial Inoculants

Sclerotium rolfsii (Sacc.) is the causal agent of stem-rot in groundnut (Arachis hypogaea L.)crop. With the increase in demand for the groundnut, control of stem-rot efficiently by microbial strains is fast becoming inevitable as the conventional system of chemicals is degrading our ecosystem. This investigation here emphasizes on inoculation of arbuscular mycorrhizal fungi (AMF) and Trichoderma species for growth achievement and disease control. The present investigation showed that these microbial strains were found to be worth applying as they stimulated growth and decreased harmful effects of S. rolfsii (cv. ‘Western-51’). The increased biochemical parameters and antioxidant activities also indicated their defence related activities in groundnut plants. In spite of positive attributes meted out by these microbial strains towards groundnut crop, the interaction among AM fungi and Trichoderma species seemed to be less co-operative between each other which were noted when mycorrhizal dependency and percent root colonization were observed. However, in summary more practical application of low-input AM fungi along with Trichoderma species may be needed for the advancement of modern agricultural systems.

Improvement of copper stress tolerance in pepper plants (Capsicum annuum L.) by inoculation with arbuscular mycorrhizal fungi

The effect of arbuscular mycorrhizal fungi (AMF) inoculation, on pepper plant growth and physiological parameters in response to increasing soil Cu concentrations was studied. Treatments consisted of inoculation or not with Funneliformis mosseae or Rhizophagus intraradices and the addition of Cu to soil at concentrations of 0, 2, 4 and 8 mM CuSO4. The increase in copper concentration diminished the inoculation in all treatments. The highest experimental concentration of Cu (8 mM) reduced significantly the hyphae viability and ALP activity, regardless of the inocula used. The total dry weight and the leaf area were higher for mycorrhizal plants. The mycorrhizal dependence was 30 and 50% for plants inoculated with F. mosseae and R. intraradices, respectively at 8 mM CuSO4. The electrolyte leakage was higher at higher Cu concentrations, in roots and leaves. Net photosynthetic rates and transpiration were lower in plants treated with Cu, regardless of the inocula. At low Cu concentration in soil no differences were observed in Cu content in the shoots and roots. At 4 mM Cu, Cu content in roots was significantly higher than in shoots. At 8 mM Cu, in non-inoculated plants accumulate more Cu than inoculated plants in the roots, leaves and fruits regardless of the inocula. Beneficial microbial inoculants such as AMF, is an attractive strategy to farmers in the context of sustainable agriculture. Pre-inoculation in transplants could be an adequate practice to alleviate the deleterious effects in stress of pepper plants. However different AMF species can differ in their ability to minimize stress effects and promote plant growth.

Short Communication: Growth response and dependency of endangered nedun tree species (Pericopsis mooniana) affected by indigenous Arbuscular Mycorrhizal Fungi inoculation

Husna, Tuheteru FD, Wigati E. 2017. Short Communication: Growth response and dependency of endangered nedun tree species (Pericopsis mooniana) affected by indigenous Arbuscular Mycorrhizal Fungi inoculation. Nusantara Bioscience 9: 57-61. Arbuscular mycorrhizal fungi (AMF) were isolated from the rhizosphere of local nedun tree or kayu kuku (Pericopsis mooniana (Thw.) Thw.) and based on the results of previous studies which showed that inoculation with AMF mix enhanced growth and nutrient uptake of seedlings P. mooniana on ultisol and serpentine soil media. Thus study aimed to determine the effectiveness of indigenous AMF on the growth and dependence of P. mooniana. P. mooniana seedlings were grown on ultisol soil medium and inoculated with and without AMF (Clareodeglomus etunicatum, Glomus sp. (HA), Glomus sp. (KDI)) and mixed (C. etunicatum, Glomus sp. (HA), Glomus sp. (KDI) for 12 weeks under greenhouse conditions. The results showed that inoculation with Glomus sp. (HA) significantly increased plant height, stem diameter, number of leaves, dry weight (roots, shoots, total), nodulation, root length and leaf length. It was better than results on control of P. mooniana seedling but it was not significantly different from other types of AMF, except on Glomus sp. (HA) on plant height. The width of the leaf and shoot-root ratio was not influenced by the AMF. P. mooniana has a high dependency (<75%) with mycorrhizal dependency (MD) value ranging from 54-68%. Glomus sp. (HA) and other types of AMF have potential to be developed to support the conservation of P. mooniana.