Vesicular-arbuscular Mycorrhizal Fungi Research Articles

Effects of solarization and vesicular arbuscular mycorrhizal fungus (VAM) on phytopthora blight (Phytophthora capsici leonian) and yield in pepper

In this work, effects of soil solarization and vesicular arbuscular mycorrhizal (VAM) fungus, Glomus intraradices on diseases caused by Phytophthora capsici Leonian in pepper plants and crop yields were studied. At the end of the growth season, 82.5% mortality of plants and 47.7% of yield loss caused by P. capsici were obtained in control plots. At the beginning of the vegetative period, plant mortality caused by P. capsici in solarized plots was less than that in non-solarized plots, but it was higher at the end of the experiments. The total crop yield, however, increased to 20.9% by solarization. At the beginning of the growth season, anthocyanin production, early flowering and fruit settings were observed in the seedlings inoculated with VAM. Plant mortality caused by P. capsici was inhibited by 69.4% in plants inoculated with VAM fungus, but this rate decreased to 14.9% at the end of the experiment. On the other hand, total yield increased to 40.4% in plots infested with P. capsici, but treated with VAM. The total yield increased to 49.9% in pathogen free solarized + VAM inoculated grown plants plots in comparison to pathogen free non-solarized + non-VAM inoculated grown plants plots. This increase was 42.8% in solarized + VAM inoculated grown plants plots, which were infested with P. capsici. Total yield was 22.7% in solarized + VAM inoculated grown plants plots without P. capsici in comparison to non-solarized plots + non-VAM inoculated grown plants plots but infected with P. capsici. The yield loss caused by P. capsiciin pepper was decreased by means of long-term effect of soil solarization with artificially VAM inoculation. Key words: Soil solarization, vesicular arbuscular mycorrhizal, Glomus intraradices, Phytophthora capsici, yield, phytopthora blight, pepper.

Temporal changes in VAM fungi in the cocoa agroforestry systems of central Cameroon

In Cameroon, cocoa trees are mostly grown in forests and without fertilization. Our aim was to learn more about the temporal dynamics of soils in cocoa agroforests by comparing young (1-4 years old) and old (over 25 years old) cocoa agroforests. Short fallow and secondary forest were used as treeless and forest references. The numbers and diversities of soil vesicular arbuscular mycorrhizal (VAM) fungi on 60 cocoa producing farms in the Central province of Cameroon were assessed based on the classical mor- photyping of spore morphology. We also observed the soil organic matter, nitrogen and major soil nutrients. VAM spore density was significantly lower in the young cocoa agroforests (16 spores g -1 dry soil) than in the old cocoa agroforests (36 spores g -1 dry soil). Levels in the nearby secondary forest (46 spores g -1 dry soil) were not significantly different from old cocoa. The spore density was significantly highest in the short fallow (98 spores g -1 dry soil). The Shannon- Weaver index also showed significantly lower biodi- versity in young cocoa (0.39) than in old cocoa agroforests (0.48), secondary forest (0.49) and short fallow (0.47). These observations were supported by significant differences in the C:N ratio, Ca, Mg, and cation exchange capacity between young and old cocoa agroforests. We concluded that unfertilized cocoa agroforests could be sustainable, despite a decrease in some soil characteristics at a young stage, due to traditional land-conversion practices based on selective clearing and burning of secondary forest.

Existing of Vesicular Arbuscular Mycorrhizal on The Corn Field Subjected by Long-term Organic and Inorganic Fertilizers

Existing of vesicular arbuscular mycorrhizal fungi were investigated in continuously cropped, conventional agro ecosystems which had received annual long-term (4 years) amendments of either manure or inorganic fertilizer. The systems had an identical 4–year crops rotation and differed essentially only in the amount and type of fertilizer supplied. Experiment was setup at Taman Bogo, in the vicinity of Probolinggo, East Lampung. The eight farming systems differed mainly in fertilization application. The organic systems were fertilized exclusively with chicken manure (CK), and green manure Glyricidium sp. (GM) 20 Mg ha-1. One conventional system was fertilized with the inorganic fertilizers (IF) (urea 300 kg ha-1, SP 36 200 kg ha-1, and KCl 100 kg ha-1). Four proportion combination fertilized organic and inorganic fertilizers i.e combination of 50% CK + 50% IF, 50% GM + 50% IF, 75% CK + 25% IF, and 75% GM + 25% IF. Application of chicken manure both exclusively or combination with inorganic fertilizer gave the higher AMF spore number and root colonization than others treatment. The dominant species of AMF at all treatment was Glomus constrictum.

Causal Agents of Root Rot and the Effect of Vesicular-Arbuscular Mycorrhizal Fungi in Seedlings of Rhodiola rosea in Alberta, Canada

Causal Agents of Root Rot and the Effect of Vesicular-Arbuscular Mycorrhizal Fungi in Seedlings of Rhodiola rosea in Alberta, Canada

Response of Some Medicinal Plants to Vesicular Arbuscular Mycorrhizal Inoculations

An investigation has been made about the response of vesicular arbuscular mycorrhizal fungi of G. fasciculatum on some medicinal plants. Medicinal plants species selected for the study are Ocimum sanctum, Catharanthus roseus, Coleus forskholii and Cymbopogon flexuosus. The percentage of VAM association is 85 and the intensity of formation of vesicles and arbuscules are 70% and 30%, respectively in VAM inoculated C. roseus plants. The total dry matter production (shoot and root dry wt), protein and total chlorophyll contents are seen to increase in VAM inoculated plants. The percentage of increase is more in C. roseus, followed by Cymbopogon flexosus when compared to control plants. Keywords: Ocimum sanctum, Coleus forskholii, Cymbopogon flexosus, Catharanthus roseus, VAM fungi.© 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.1675

Genetic and phenotypic diversity of geographically different isolates ofGlomus mosseae

In this work, we combined morphological taxonomy and molecular methods to investigate the intraspecific diversity of Glomus mosseae, whose global distribution has been reviewed by a survey of scientific literature and Web-available records from international germplasm collections (International Culture Collection of Vesicular Arbuscular Mycorrhizal Fungi and International Bank of Glomeromycota). We surveyed 186 publications reporting the occurrence of G. mosseae from at least 474 different sites from 55 countries throughout all continents, producing a geographical map of their distribution. The relationships among G. mosseae isolates originating from Europe (United Kingdom), the United States (Arizona, Florida, and Indiana), Africa (Namibia), and West Asia (Syria) were analyzed. The level of resolution of internal transcribed spacer (ITS) sequences strongly supports the morphological species definition of G. mosseae. An ITS - restriction fragment length polymorphism assay with the enzyme HinfI yielded a unique profile for all G. mosseae isolates, allowing a straightforward identification of this morphospecies. Genetic variability among G. mosseae isolates was revealed by the inter-simple-sequence repeat (ISSR) - polymerase chain reaction: the magnitude of genetic divergence shown by the investigated geographical isolates was higher than 50%, consistent with previous data on vegetative compatibility and functional diversity. The variability of ISSR patterns suggests that intraspecific diversity is much higher than that foreseen by morphology and rDNA regions, and should be further investigated by using other genes, such as those related to functional diversity.

Alberta and Saskatchewan Joint Regional Meeting, 2008

Alberta and Saskatchewan Joint Regional Meeting, 2008

Integration of soil solarization and chemical sterilization with beneficial microorganisms for the control of white root rot and growth of nursery apple

White root rot ( Dematophora necatrix (Mart.)) is a serious disease of apple ( Malus domestica Borkh) in nurseries and orchards in India. In 2002 and 2003, field experiments were conducted to integrate soil solarization with native isolates of Azotobacter chrococcum and vesicular–arbuscular mycorrhizal fungi and observe its effect on the incidence of white root rot and growth of the saplings. Apple seeds coated with two native isolates of A. chrococcum (AZUHF 1 and AZUHF 2) were sown in plots inoculated with 4 native isolates of va-mycorrhiza, i.e. AMUHF 1 ( Glomus fesiculatum), AMUHF 2 ( Glomus macrocarpum), AMUHF 3 ( Glomus mosseae) and AMUHF 4 ( Gigaspora sp.) in 14 different combinations and these plots were solarized with transparent polyethylene mulch (25 μm thick) for 40 days in summer months. Soil solarization resulted around 9 °C higher temperature with average maximum temperature of 38–39 °C. Inoculation of saplings with AMUHF 1 isolate of va-mycorrhiza and AZUHF 1 isolate of A. chrococcum and then their planting in solarized soil was found most effective with no incidence of white root rot in comparison to 33.6–35.4% in control accompanied with 78–113% increase in shoot length and 81.6–84.3% increase in root length. Shoot and root length of the saplings was 9.6–10.6 and 9.2–16.0% higher, respectively, in solarized plots in comparison to sterilized plots.

Near infrared spectroscopy for determination of various physical, chemical and biochemical properties in Mediterranean soils

The potential of near infrared (NIR) reflectance spectroscopy to predict various physical, chemical and biochemical properties in Mediterranean soils from SE Spain was evaluated. Soil samples ( n = 393) were obtained by sampling 13 locations during three years (2003–2005 period). These samples had a wide range of soil characteristics due to variations in land use, vegetation cover and specific climatic conditions. Biochemical properties also included microbial biomarkers based on phospholipid fatty acids (PLFA). Partial least squares (PLS) regression with cross validation was used to establish relationships between the NIR spectra and the reference data from physical, chemical and biochemical analyses. Based on the values of coefficient of determination ( r 2) and the ratio of standard deviation of validation set to root mean square error of cross validation (RPD), predicted results were evaluated as excellent ( r 2 > 0.90 and RPD > 3) for soil organic carbon, Kjeldahl nitrogen, soil moisture, cation exchange capacity, microbial biomass carbon, basal soil respiration, acid phosphatase activity, β-glucosidase activity and PLFA biomarkers for total bacteria, Gram-positive bacteria, actinomycetes, vesicular-arbuscular mycorrhizal fungi and total PLFA biomass. Good predictions (0.81 < r 2 < 0.90 and 2.5 < RPD < 3) were obtained for exchangeable calcium and magnesium, water soluble carbon, water holding capacity and urease activity. Resultant models for protozoa and fungi were not accurate enough to satisfactorily estimate these variables, only permitting approximate predictions (0.66 < r 2 < 0.80 and 2.0 < RPD < 2.5). Electrical conductivity, pH, exchangeable phosphorus and sodium, metabolic quotient and Gram-negative bacteria were poorly predicted ( r 2 < 0.66 and RPD < 2). Thus, the results obtained in this study reflect that NIR reflectance spectroscopy could be used as a rapid, inexpensive and non-destructive technique to predict some physical, chemical and biochemical soil properties for Mediterranean soils, including variables related to the composition of the soil microbial community composition.

Rhizobacteria in Mycorrhizosphere Improved Plant Health and Yield of Banana by Offering Proper Nourishment and Protection against Diseases

The corporate R&D banana orchards of Musa paradisiaca (dwarf Cavendish AAA, var. shrimanti) on a medium black alluvial soil with low nutrients harboured diversified species of vesicular-arbuscular mycorrhizal (VAM) fungi. These fungi infected the roots severely (69.2%), showed elevated (69.8 g(-1) soil) spore density, increased soil bacterial density (245 x 10(8) cfu g(-1)), produced siderophores (58.2%) and reduced nematode population (2.3 g(-1)) in the mycorrhizosphere of plants for integrated plant nutrition management (IPNM) system as compared to traditional treatment of applying chemical fertilisers alone and other test treatments. The interactions of plant roots with native VAM and local and applied rhizobacteria in the matrix of soil conditioner enabled proper nourishment and protection of crop in IPNM treatment as compared to traditional way. Hence, exploitation of plant growth promoting rhizobacteria through judiciously designed IPNM system revealed the (a) relatively increased banana productivity (21.6%, 76 MT ha(-1)), (b) least occurrence of fusarial wilt and negligible evidence of Sigatoka, (c) saving of 50% chemical fertilisers and (d) permitted control over soil fertility in producer's favour over traditional cultivation practices. These findings are discussed in detail.

Tangerineira ‘cleópatra’ submetida a micorrização e a um análogo de brassinosteróide

The objective of this study was to evaluate the effects of different concentrations of a brassinosteroid analogue and inoculation of the vesicular-arbuscular mycorrhizal fungi (AMF) Acaulospora scrobiculata on the ‘Cleópatra’ mandarin from the sowing until transplant point. The experiment was conducted under greenhouse conditions at Universidade Estadual do Norte Fluminense. The experimental design utilized was a randomized block with a 5 x 2 factorial scheme with 4 replications, using 5 concentrations of a brassinosteroid analogue, Biobras-16 (0.0; 0.1; 0.5 and 1.00 mg L-1) and with or without AMF inoculation. The AMF inoculation caused increment in height, number of leaves, diameter of the stem, leaf area and dry mass of the leaf and stem. The Biobras-16 promoted an increment of the diameter of the stem. The P, K, Fe and Mn contents were higher in the AMF inoculated plants. Results show that the association of the two factors studied modifies the growth of rootstock

OPTIMIZATION OF NITRIC AND PHOSPHORIC SUPPLY FOR CHICK PEA

The presowing inoculation of chick pea seeds with M. ciceri high efficient strains in the field experiments of southern Steppe of Ukraine non-irrigation soils increased the seed yield by 1,4–5,5 c/ha. Application of phosphoric fertilizer in doses of P10 (row application) and P60 (plowed-under application) did not influencing triple symbiosis Cіcer arіetіnum − Mesorhizobium cіcerі − vesiculararbuscular mycorrhizal fungi negatively.

Arbuscular mycorrhizal fungi in northern Greece and influence of soil resources on their colonization

Summary Abundance of arbuscular mycorrhizal fungi (AMF) in the roots of plant species was assessed in two areas in Greece in a 4-year study (2004–2007). The field experiment was conducted in a mountainous and herbaceous grassland in Greece in which both nitrogen (N)- and phosphorus (P)-limited plant community productivity. In 2006, data were also collected from a pot experiment in which 14 herbaceous plant species were grown as monocultures in P-limited soil. A factorial design of two levels of N and P was established in the mountainous field to test plant response to nutrient additions with respect to AMF colonization levels. Effects of fungicides were also investigated over year in the pot experiment and over three years in the field experiment. In addition, the effect of irrigation on AMF colonization was determined in a 1-year field study. Measurements included estimating the level of plant species specific hyphal colonization of roots according to the McGonicle et al. [McGonigle, T.P., Miller, M.H., Evans, D.G., Fairchild, D.L., Swan, J.A., 1990. A new method which gives an objective measure of colonization of roots by vesicular–arbuscular mycorrhizal fungi. New Phytol. 115, 495–501] method. AMF colonization was highest in the leguminous species, intermediate in the forbs and lowest in the grasses. AMF responses to N and P additions were not uniform. P addition in the field experiment increased the colonization level of the high P demanding annual forb (non-leguminous dicot) Galium lucidum , decreased hyphal abundance of the forb Plantago lanceolata and the grass Agrostis capillaris , and appeared to have a negligible effect on the forb Prunella vulgaris and on leguminous species. Effects of N addition were influenced by P addition and were only significant in plots not enriched with P where N addition increased the AMF colonization. Irrigation increased colonization of the tested species A. capillaris and P. lanceolata but only significantly increased that of P. lanceolata . There was interannual variation in the effects of fungicides on AMF colonization, which was partly due to differences in the active ingredient and formulation used. Among the tested species, A. capillaris was the most susceptible to fungicides.

Influence of Ultraviolet-C Radiation on Some Growth Parameters of Mycorrhizal Wheat Plants

UV-C radiation (220-280 nm) is known to causing damage in some physiological growth parameters such as chlorophyll, carotenoid, protein and sugar contents. In this study, effect of some species of vesicular arbuscular mycorrhizal fungi on tolerance of UV-C radiation in wheat plants was studied. Wheat (Triticum aestivum L. cv. Azar2) plants colonized by three species of mycorrhizae namely Glomus etunicatum, Glomus intraradices and Glomus veruciforme were used in this study. They have been exposed to UV-C (254 nm) light for 7 h (28 days, 15 min each day). We measured total proteins, sugars, chlorophyll a and b and carotenoids. Our study showed that UV-C radiation decreases chlorophylls, carotenoids and sugars contents. But this effect on total proteins content has not been significant. However, mycorrhizal fungi could increase all of these factors in comparison to non-mycorrhizal samples. Therefore, these fungi species can increase above growth factors of wheat plants, apparently.

INFLUENCE OF VESICULAR ARBUSCULAR MYCORRHIZAE, NK FERTILI-ZATION RATES AND FOLIAR APPLICATION OF MICRONUTRIENTS ON GROWTH, YIELD AND QUALITY OF POTATOES

This work was carried out in two successive summer plantations of 2004 and 2005 on potatoes cv. Spunta at Abou Awad village , Aga, Dakahlia Governorate, to study the influence of Vesicular Arbuscular Mycorrhizal (VAM) fungi , nitrogen and potassium fertilization at rates of 50, 75 and 100% of recommended rate / fed. with foliar spraying of micronutrients (Fe150 , Zn 75, and Mn 75 ppm) and their interactions on plant growth , yield and its components, as well as chemical composition .Application of the tested rates of nitrogen and the potassium induced significant increase in vegetative characteristics (plant height, foliage fresh and foliage dry weight) total tuber yield (t/fed) , number of tubers/plant and tuber weight/plant, tuber dry matter , starch and nitrate content in tuber, as well as N,P and K concentra-tions in the leaves and micronutrients in the leaves (Fe, Mn and Zn) in both seasons.Similarly, plant height, chlorophyll content, fo-liage fresh and dry weights , total yield (t/fed), number of tubers , tuber weight/ plant, tuber dry weight , starch and nitrate content in tuber, NPK concentration in leaves and tubers , micronutrient content (Fe, Zn and Mn) in leaves gave the highest values with inoculation by VA Mycorrhizal fungi and some micronutrients .The interaction between NK, VAM fungi and micronutrient gave the highest values of vege-tative growth characteristics, number of tu-bers/plant, NPK in leaves and tubers and micronu-trients (Zn and Mn) in leaves when potatoes was fertilized with 100% NK of the recommended rate and inoculate with VAM fungi plus foliar spraying by micronutrients (Fe, Zn and Mn).as well as total yield (t/fed), tuber weight/plant, tuber dry weight, starch content in tuber , Mn and Zn in leaves, while The lowest content of nitrate in tubers was found when plants were applied with 50 (%) NK of recommended rate with inoculation by VA My-corrhizal fungi.Generally, the best results were obtained when potato received 75 % of NK of the recommended rate, inoculated by VA Mycorrhizal fungi and sprayed with micronutrients at dose of Fe 150, Mn 75 and Zn 75 ppm. This treatment resulted in the highest total tuber yield and its components and reduced chemical fertilizer inputs.

Plant Germplasm Centers and Microbial Culture Collections: A User's Guide to Key Genetic Resources for Plant Pathology.

Collections containing microbes (often referred to as “culture collections”) and collections of seeds or clonal materials for higher plants (often referred to as “germplasm collections”) can provide abundant resources for plant pathologists, breeders, geneticists, and other plant science professionals. However, many such professionals (including graduate students, postdoctoral fellows, and technical staff) lack adequate guidance on locating, obtaining, and processing such materials. Regulatory procedures and considerations of biological security, ambiguities regarding intellectual property rights, lack of knowledge about collection databases, and other hurdles dissuade many professionals from effectively exploiting collection resources. The Collections and Germplasm Committee of the American Phytopathological Society, together with colleagues from international collections and the World Federation of Culture Collections, has assembled this guide summarizing the benefits and utilization of living collections for plant pathology. We show how to locate major and minor collections, obtain biological materials, and comply with regulatory and shipping requirements. We briefly discuss the relevance of intellectual property rights, the problem of endangered collections (especially those with invaluable and irreplaceable materials), and make specific recommendations for the support of living collections. Prior reviews of culture collections originated from diverse perspectives. Examples from an extensive literature are quality control and preservation (27,41, 47,54,68), taxonomy and research (13,26), organizations, legislation, and regulation (77), relevance to plant pathology and other disciplines (51,52,73), and genomics (50,68). Capsule histories of several culture collections, plus extensive lists of associated databases, are available (50). Public seed banks have been subjected to similar review. The USDA-Agricultural Research Service National Plant Germplasm System (NPGS) was the subject of detailed reporting, covering history (66,83), management (16), quality control and preservation (10,65,82), structure (1,16,86), personnel (86), information technology (53,67), conserved species (38,66), collecting of germplasm (58,84), and examples of associated research (86). For Canada, the locations and holdings of seed banks and clonal repositories were reviewed, and instructions were provided for online viewing and ordering of holdings (8). Earlier, multifaceted reviews (7,9) gave a worldwide perspective on plant germplasm. The fiscal health of collections has been the subject of repeated reviews (or perhaps more accurately, laments) and news items (2,11,73). Although we firmly acknowledge the importance of nonliving collections (museums and herbaria), we have chosen to restrict our discussion to collections of living materials. Readers wishing to learn more about herbaria and other nonliving collections are referred to other sources (37,46,87). Here, we concentrate on collections containing organisms that can be maintained in refrigerated conditions (as with many seeds or clonal stocks of higher plants) or grown in culture and then lyophilized or kept in cryogenic storage at ultra-low temperatures (as with many microorganisms). Some obligate parasites or symbionts are also kept in collections (e.g., plant viruses, vesicular-arbuscular mycorrhizal fungi and rusts), either in cryogenic storage or by maintaining them on their plant hosts.

The relationships between relative water content, chlorophyll synthesis and yield performance of yam (Dioscorea rotundata) as affected by soil amendments and mycorrhizal inoculation

The response of yam to inoculation with two species of vesicular-arbuscular mycorrhizal (VAM), Glomus mosseae and Glomus etunicatum and applications of fertilizer, and manure was investigated. Field experiment was conducted at the research farm of Botany and Microbiology Department, University of Ibadan, Nigeria. The treatments were arranged in a factorial randomized complete block design. There were four levels of VAM inoculation. The yam plants were either inoculated with a VAM fungus or not. Manure and NPK fertilizer were also applied as treatments. Each of the VAM was either combined with manure or NPK fertilizer. Chlorophyll synthesis, relative water content (RWC) and dry matter accumulation were investigated. The results showed that there was enhanced chlorophyll content in yam inoculated with the VAM with G. mosseae being more effective when combined with manure. RWC and yield of yam were also significantly influenced by the treatments. RWC was found to affect the chlorophyll production when water became limited. Chlorophyll content was also found to have effect on yam productivity. Combinations of mycorrhizae with the soil amendments are highly promising for sustainable yam production in degraded soils.

An invasive aster (Ageratina adenophora) invades and dominates forest understories in China: altered soil microbial communities facilitate the invader and inhibit natives

Exotic plant invasion may alter underground microbial communities, and invasion-induced changes of soil biota may also affect the interaction between invasive plants and resident native species. Increasing evidence suggests that feedback of soil biota to invasive and native plants leads to successful exotic plant invasion. To examine this possible underlying invasion mechanism, soil microbial communities were studied where Ageratina adenophora was invading a native forest community. The plant–soil biota feedback experiments were designed to assess the effect of invasion-induced changes of soil biota on plant growth, and interactions between A. adenophora and three native plant species. Soil analysis showed that nitrate nitrogen (NO3−-N), ammonium nitrogen (NH4+-N), and available P and K content were significantly higher in a heavily invaded site than in a newly invaded site. The structure of the soil microbial community was clearly different in all four sites. Ageratina adenophora invasion strongly increased the abundance of soil VAM (vesicular-arbuscular mycorrhizal fungi) and the fungi/bacteria ratio. A greenhouse experiment indicated that the soil biota in the heavily invaded site had a greater inhibitory effect on native plant species than on A. adenophora and that soil biota in the native plant site inhibited the growth of native plant species, but not of A. adenophora. Soil biota in all four sites increased A. adenophora relative dominance compared with each of the three native plant species and soil biota in the heavily invaded site had greater beneficial effects on A. adenophora relative dominance index (20% higher on average) than soil biota in the non-invaded site. Our results suggest that A. adenophora is more positively affected by the soil community associated with native communities than are resident natives, and once the invader becomes established it further alters the soil community in a way that favors itself and inhibits natives, helping to promote the invasion. Soil biota alteration after A. adenophora establishment may be an important part of its invasion process to facilitate itself and inhibit native plants.

Biofertilizers: An Alternative Source of Nutrients for Sustainable Production of Tree Crops

ABSTRACT Certain microorganisms fix atmospheric nitrogen in the root nodule of trees by establishing a symbiotic relationship. Rhizobium usually infects legume trees for nodulation while Frankia is an actinomycete, which is known for actinorhizal symbiosis with nonlegumes. However, Azospirillium is an associative symbiotic nitrogen-fixing organism. Vesicular arbuscular mycorrhizal (VAM) fungi help plants absorb phosphorous. These four microorganisms were examined in the present study. An experiment was conducted by inoculating Frankia, Rhizobium, and Azospirillum either singly or in combination with VAM to Casuarina equisetifolia, Acacia nilotica and Eucalyptus tereticornis. The inoculation resulted in high biomass built up over control. Casuarina equisetifolia and Acacia nilotica developed more nodules with higher nodule dry mass and high nodule nitrogenase activity compared to control. From the result it is important to note that the dual inoculation namely Frankia + VAM, Rhizobium + VAM, and Azosprillum + VAM showed higher productivity than single inoculation in all the above three tree species.

POPULASI JAMUR MIKORIZA VESIKULAR-ARBUSKULAR PADA LAHAN BEKAS GALIAN EMAS YANG DIREKLAMASI DENGAN LEGUM TUMBUH CEPAT DIKOMBINASIKAN DENGAN PENUTUP TANAH DAN MIKROBA

A field work has been carried out to study the population of vesicular-arbuscular mycorrhizal (VAM) fungi on degraded gold mining land that was reclamated with fast growing legume (Enterolobium sp. and Acacia mangium) trees in combination with cover crops (Centrosema pubescen dan Flemingia congesta) and microbe (VAM fungi, Rhizobium sp. and mixed Rhizobium sp. and phosphate solubilizing bacteria) inoculation. Reclamation with fast growing legumes in combination with cover crops and microbe inoculation on the degraded land increased the population of VAM fungi. After 1.5 years, the population of the fungi on the reclamated land increased from 3.4 (control) to 6.1–80.5 spore/g soil. The highest spore population resulted by combination between Acacia mangium, C. pubescen, and VAM fungi (V2I1C1) plot followed by combination between Acacia mangium without cover crop, and VAM fungi inoculation (V2I1C0) plot and combination between Enterolobium sp. without cover crop and mixed Rhizobium and phosphate solubilizing bacteria inoculation (V1I3Co) plot were 80.5, 56.0 and 51.8 respectively.