Arbuscular Mycorrhizal Fungi Spores Research Articles

AM fungal diversity and its impact across three types of mid-temperate steppe in Inner Mongolia, China.

Arbuscular mycorrhizal (AM) fungal diversity was measured in three different natural mid-temperate steppe types: the meadow steppe, typical steppe, and desert steppe. In these steppe soils, 24 AM fungal species from eight genera were identified, in which Glomus had the highest relative abundance. Funneliformis geosporus, Glomus microaggregatum, and Septoglomus constrictum had high relative abundance and were found widely across varying soil depth and steppe type. Meadow steppes had significantly higher AM fungal species richness compared to typical steppes and desert steppes, but there was no significant difference between typical steppes and desert steppes. AM fungal spore density, two Bradford-reactive soil protein (BRSP) fractions, and extraradical hyphal length densities (HLDs) were significantly different among the three steppe types. Alkaline phosphatase and acid phosphatase activity, urease activity, and soil bacterial and actinomycotic quantity were significantly related to the AM fungal spore density and species richness in these arid and semi-arid steppes. Therefore, steppe types could influence the distribution pattern of AM fungal diversity and the content of glomalin-related soil protein (GRSP).

Adult plants facilitate their conspecific seedlings by enhancing arbuscular mycorrhizae in a saline soil

We tested the hypothesis that adult plants can help their conspecific (i.e. an organism belonging to the same species as another organism) seedlings develop symbiosis with arbuscular mycorrhizal fungi (AMF), thereby increasing seedling nutrient uptake and growth in a saline soil. Using the halophytic shrub Tamarix chinensis as a model plant, we conducted two field experiments and a greenhouse experiment. Field experiment 1 assessed the importance of below-ground effects of adult neighbor. Field experiment 2 determined the involvement of AMF in neighbor effects by applying fungicide benomyl to obtain AMF suppressed treatment. The greenhouse experiment tested whether neighbor effects were influenced by AMF hyphal connection between adults and seedlings by using 25 μm and 0.45 μm nylon mesh to allow and prevent the AMF hyphae pass through respectively. Adult neighbor increased shoot biomass and nutrient of target seedlings and the below-ground effects mediated by AMF was facilitative under high soil salinity level. Field experiment 1 showed that adult neighbors reduced soil salinity, increased soil organic matter, and provided AMF spores for target seedlings via whole plant effects or below-ground effects alone. Field experiment 2 showed that shoot biomass and AMF colonization of target seedlings were greater with an adult neighbor when AMF were not suppressed treatment than in AMF were suppressed or there were no neighbors. In the greenhouse experiment, adult neighbors with AMF hyphal connection increased shoot biomass, AMF colonization, and 15N content of target seedlings under the high salinity level. The results support our hypothesis that adult plants can promote the growth and nutrient uptake of their conspecific seedlings in a saline soil by helping them to develop AMF symbiosis. These findings highlight the roles of adult neighbor plants on seedlings regeneration through rhizospheric symbiosis in stressful environments.

CHARACTERIZATION OF RHIZOBIA AND ARBUSCULAR MYCORRHIZAL FUNGI IN AREAS IMPACTED BY GRAVEL MINING IN BRAZIL

ABSTRACT On-shore oil exploration is one of the main economic activities in the semiarid region (Caatinga biome) of the state of Rio Grande do Norte (RN), Brazil. Gravel mining is an activity associated with oil exploration that causes environmental impacts. Gravel is a base-material for constructions, such as roads and pumpjack bases. The areas of gravel mining and other decommissioned areas where the gravel has been deposited must be revegetated with species native to the biome at end of the activity in the site. An efficient strategy for revegetation of degraded areas has been the planting of leguminous species that can associate with rhizobia and arbuscular mycorrhizal fungi (AMF). Nevertheless, the impact of mining activities on the autochthonous populations of these microorganisms is unknown. The objective of the present work is to characterize the density of rhizobia and AMF spores in four areas impacted by the oil exploration in RN when compared to non-impacted adjacent areas. Gravel samples were collected in dry and rainy seasons in two mining areas: one in a pumpjack base, and one in a waste disposal area. Surface soil (topsoil) samples were collected in adjacent areas with native Caatinga vegetation. Assays were carried out to evaluate the most probable number (MPN) of rhizobia and to identify the type and density of arbuscular mycorrhizal fungi (AMF), using rhizobia trap plants Mimosa tenuiflora (Mart.) Benth. and Mimosa caesalpiniifolia Benth. The MPN of rhizobia was low in all areas, but higher in the rainy season. The highest amount and diversity of AMF spores were found in the dry season. Among the symbiotic microorganisms studied, the AMF presented lower densities in the evaluated areas when compared to those in the adjcent native vegetation areas, denoting the impact of this activity.

Effect of inoculation with native and commercial arbuscular mycorrhizal fungi on growth and mycorrhizal colonization of olive (Olea europaea L.)

In order to improve the production of olive (Olea europaea L.), plantlets of Variety Ferkani were inoculated with three arbuscular mycorrhizal fungal (AMF) spores (Glomus sp.1, Glomus sp.2, Septoglomus constrictum) isolated from a hot-arid zone in Algeria and three commercial AMF (Rhizophagus intraradices, Funneliformis mosseae, Gigaspora margarita). Mycorrhization parameters and nine growth traits were estimated in two-year-old plantlets, then the variation of growth traits following mycorrhizae parameters of various AMF inoculums was tested. The tested AMF species were all infective and effective for the mycorrhization of Ferkani variety. Native species Glomus sp.1 gave the best results for mycorrhizal colonization and growth parameters. Indeed, the highest colonization frequency (F%) was recorded in plantlets inoculated with Glomus sp.1 (58 ± 6.5 %), whereas the highest values of colonization intensity of in the root system (M%) were obtained with Rhizophagus intraradices (2.45 ± 1.46 %) and Glomus sp.1 (2.26 ± 0.76 %). Abundances of arbuscules were low for all AMF inoculums. The controlled inoculation improved the growth of all plantlets compared to the AMF-free plantlets. AMF-inoculated plantlets showed significantly higher growth in terms shoot height, fresh and dry weights of shoot and root, and number of leaves and nodes. Statistical models revealed that all the latter growth parameters including mycorrhizal responsiveness increased significantly when mycorrhizal parameters increased, and that F% was most strongly correlated with plant growth compared to other mycorrhizal parameters. Findings of this controlled inoculation research underline the importance of local AMF isolated from the rhizosphere of Ferkani variety in rapidly and extensively infecting the root system and then increasing growth of the host.

Glomus fasciculatum, a dominant arbuscular mycorrhizal species in the rhizosphere soils of Setaria italica in Mahabubnagar district of Telangana state, India

The arbuscular mycorrhizal (AM) fungal association in the rhizosphere soils of Setaria italica (L.) P. Beauv. from 8 Mandals of Mahabubnagar district, Telangana state, India, were studied. A significant number of AM fungi were identified in the present study, i.e., 53. Among the 53 AM fungi, Glomus was represented by 23 species, Acaulospora with 11, Sclerocystis with 6, Scutellospora with 5, Gigaspora with 4, and Funneliformis with 2, Ambispora and Archaeospora with 1 species. Glomus fasciculatum was the dominant species among the Glomus genera isolated from the rhizosphere soil samples of 34 villages in Mahabub Nagar district of Telangana State. The AM fungi spore density ranged from 74 to 270 per 100 gm soil (average 145), while the root colonization ranged from 50.67% to 93.33% (average 75.71%). This study provides valuable information on AM fungal association in Setaria italica.

Effect of crop and grassland management on mycorrhizal fungi and soil aggregation

High rates of fertilizer application can disturb the Arbuscular mycorrhizal fungi (AMF) occurrence and life cycle in different tropical crop/ grassland systems compared to native vegetation. With the purpose of examine benefic AMF for crop production in experimental farms, the AMF community structure across different sites was studied. The native forest showed a greater diversity of AMF, followed by the grassland and cultivated crops. The number of AMF spores was greater in the natural site where ten genera of Glomeromycota, 14 species and four morphotypes were detected. The preserved native forest showed exclusive characteristics: higher amount of soil organic matter and higher macroaggregates and charcoal content than the samples of cultivated sites. This study showed variances in AMF communities as well as potential for AMF inoculant formulation.

Amycolatopsis eburnea sp. nov., an actinomycete associated with arbuscular mycorrhizal fungal spores.

A novel actinomycete, designated strain GLM-1T, was isolated from arbuscular mycorrhizal fungal spores from Funneliformis mosseae RYA08, collected from Aquilaria crassna Pierre ex Lec. rhizosphere soil in Klaeng, Rayong Province, Thailand. Morphological characteristics of this strain included long chains of rod-like cells and squarish elements. The cell-wall composition of this novel isolate contained meso-diaminopimelic acid. The whole-cell diagnostic sugars were arabinose and galactose. The predominant menaquinone was MK-9(H4). The major fatty acids were iso-C16 : 0 and iso-C15 : 0. Only phosphatidylethanolamine was detected as a polar lipid. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain GLM-1T was closely related to Amycolatopsis rhabdoformis SB026T (99.11 %) with a low DNA-DNA hybridization value of 22.6-34.7 %. Genome sequencing revealed a genome size of 10 Mbp. There were obvious distinctions in the average nucleotide identity values between stain GLM-1T and its closely related strains at around 86-93 % (ANIb) and 89-94 % (ANIm). The digital DNA-DNA hybridization values between strain GLM-1T and type strains of phylogenetically related species were 34-55 %. The G+C content of the genomic DNA was 71.8 mol%. Based on these data, strain GLM-1T is considered to represent a novel species of the genus Amycolatopsis, for which the name Amycolatopsiseburnea sp. nov. is proposed. The type strain is GLM-1T (=TBRC 9315T=NBRC 113658T).

Diversity of Arbuscular Mycorrhizal Fungi as Affected by Time Consequences Revegetation Age in Post Coal Mine Area at PT Berau Coal Tbk, East Kalimantan Indonesia

Arbuscular Mycorrhizal Fungi (AMF) is one of the fungi that can be found in almost every ecosystem including post-coal mining land. This study aims to analyze the diversity of AMF in different age of revegetation of post-coal mining land area. Soil samples were collected from six different age of revegetation of post-coal mining area (unrevegetated area, 0, 2, 4, 6 and 8 years) and from natural forest as comparison. AMF spore isolation was carried out using wet-sieving method, while spore identification was carried out based on several morphological characters according to INVAM guideline. The results of the observation showed that with increasing of revegetation age will be able to increase the number of AMF populations (R2= 84.96%). The highest AMF population was found at the age of 10 years after revegetation of land with the number of 492 spores per 20 grams soil, while the lowest AMF population was found in unrevegetated area with the number of 12 spores per 20 grams of soil. AMF genera found included Glomus, Acaulospora, Gigaspora, Scutellospora, and Dentiscutata. Glomus and Acaulospora were the dominant AMF in every land revegetation age (100% of frequency). AMF populations was correlated strongly with soil organic content (r = 0.79).

Exogenous abscisic acid and root volatiles increase sporulation of Rhizophagus irregularis DAOM 197198 in asymbiotic and pre-symbiotic status.

Several studies have demonstrated asymbiotic growth and development of arbuscular mycorrhizal (AM) fungi, although AM fungi are regarded as obligately symbiotic root-inhabiting fungi. Phytohormones, root exudates, and volatiles are important factors regulating the host-AM fungi interaction. However, the effects of phytohormones, root exudates, and volatiles on asymbiotic (without roots present) or pre-symbiotic (with roots present but no colonization) sporulation of AM fungi are unexplored. In this study, we tested the asymbiotic sporulation of Rhizophagus irregularis DAOM 197198 and further investigated the influences of abscisic acid (ABA), the exudates, and volatiles of tomato hairy roots on asymbiotic or pre-symbiotic sporulation in vitro. Results indicated that mother spores asymbiotically and pre-symbiotically produced daughter spores singly or in pairs. Compared with symbiotically produced spores, pre-symbiotically produced spores were significantly smaller (43.1μm vs. 89.2μm in diameter). Exogenous ABA applied to mother spores significantly increased the number of daughter spores, and root volatiles also significantly promoted pre-symbiotic sporulation. Our results provide the first evidence that exogenous ABA can promote AM fungal asymbiotic and pre-symbiotic sporulation, which highlights the potential role of phytohormones in AM fungal propagation.

Growth response of cacao (Theobroma cacao L.) plant as affected by bamboo biochar and arbuscular mycorrhizal fungi in sterilized and unsterilized soil

Abstract Biochar and arbuscular mycorrhizal fungi (AMF) are found to improve crop productivity affecting the nutrient availability in the soil and favoring build-up of beneficial microbes. The effects of AMF and bamboo biochar (BB) on the growth of cacao, estimated number of mycorrhizal spores, and soil chemical properties were investigated. Cacao seedlings were grown in unsterilized and oven-sterilized acidic soil. After 15 months, AMF generally increased most growth traits of cacao plant over the control. Bamboo biochar at 15%, gave the best plant growth regardless of soil sterilization. When biochar was added to AMF, 15% consistently provided the heaviest total plant dry weight, especially in unsterilized soil. Likewise, all treatments improved the height and stem diameter increments of those grown in unsterilized soil. Percentage of mycorrhizal root colonization was higher in mycorrhizal (+AMF) plant and addition of biochar proliferated AMF spores in the rhizosphere. Biochar showed positive effect in enhancing the soil chemical properties. The results imply that biochar and AMF can improve the overall growth and can positively increase the yield of cacao plants, which will provide impact in improving cacao production in acidic soils in the Philippines.

Standardization of spore load for AMF inoculation and its effect on rice root colonization and root system architecture in vitro

Arbuscular Mycorrhizal Fungi (AMF) can form symbiotic relationship with rice, preferably in the modern rice production systems such as System of Rice Intensification (SRI), aerobic and upland conditions. Their association with rice roots under in vitro conditions was investigated in this study. A suspension containing one lakh (1, 00,000) spores of Rhizophagus irregularis was employed to standardize optimum AMF spore load/seedling and evaluate its effect on Root System Architecture (RSA). The results indicated that different spore loads of AMF inoculated with rice seedlings, under in vitro conditions, modified most of the traits of RSA of rice at early stages significantly better than the uninoculated Control. The in vitro study clearly showed that the seedlings of rice with AMF inoculated with a dose of 14 µl/seedling (31 spores/ seedling) recorded maximum root colonization of 100 per cent by AMF in rice..

Biogeography of arbuscular mycorrhizal fungal communities in saline ecosystems of northern China

Arbuscular mycorrhizal (AM) fungi, influencing many important ecosystem processes, widely occur in saline soils, and thus understanding their biogeographic patterns is of primary interest in saline ecosystem restoration. Fine roots and rhizosphere soils were sampled in black locust (Robinia pseudoacacia) plantations in four saline sites in northern China to detect soil properties and AM fungal attributes including their colonization level, spore density, hyphal density and community composition. Arbuscular mycorrhizal fungal attributes varied with sampling sites, and this variation was mostly attributed to changes in habitat characteristics and geographic distance. Habitat characteristics shape the root- and soil-inhabiting AM fungal communities to the same extent, whereas geographic distance seems to contribute more to root-inhabiting AM fungal assemblages. The level of root colonization by vesicles, arbuscules and hyphae and the density of AM fungal spores and hyphae in soils were found to be related to the relative abundance of AM fungal species such as root-inhabiting Rhizophagus intraradices and soil-inhabiting Sclerocystis sinuosa. All the results suggest that changes in habitat characteristics and geographic distance may induce biogeographic patterns of AM fungi, and these patterns are closely related to AM symbiosis in roots and the development of AM fungi in soils.

Plant-soil feedback of two legume species in semi-arid Brazil.

Positive feedback between arbuscular mycorrhizal fungal (AMF) and vascular plants can contribute to plant species establishment, but how this feedback affects plant invasion by Prosopis juliflora SW. (DC.), or resistance to invasion by Mimosa tenuiflora (Willd.) Poir in Brazilian semi-arid region is not well known. In this work, we tested how modified and native AMF communities affect the establishment of P. juliflora and M. tenuiflora plants. We examined the effects of inoculation with modified and native AMF communities on number of AMF spores, root colonization, number of N-fixing nodules, plant dry biomass, plant phosphorous concentration, and plant responsiveness to mycorrhizas of P. juliflora and M. tenuiflora. We found that the modified AMF community enhanced the root colonization, plant dry biomass, and plant phosphorous concentration of invasive P. juliflora, whereas native AMF enhanced M. tenuiflora. Our results demonstrate that the invasive P. juliflora alters soil AMF community composition, and this change generates positive feedback to the invasive P. juliflora itself and decreases AMF associations with native M. tenuiflora.

The role of integrated watershed management on soil-health in northern Ethiopia

ABSTRACTIntegrated watershed management (IWSM) technologies have been implemented around the world, including in the northern highlands of Ethiopia during the last few decades. However, their role in improving soil-health along different geological formations is not well studied. This study was, thus, aimed at quantifying the impact of IWSM on soil-health under dolerite and sandstone geological formations. Twelve soil samples were taken from two watersheds with IWSM and another 12 soil samples from two watersheds without IWSM at 30 cm soil depth. Physical, chemical, and biological properties of these soil samples were then analysed in a laboratory. Soil moisture content, Soil organic matter, total nitrogen, available phosphorus (Pav) and arbuscular mycorrhizal fungi spore density of soils were significantly high in watersheds with IWSM as compared to watersheds without IWSM. Although insignificant, total porosity, cation exchange capacity, Exchangeable bases and micronutrients also had higher mean value on watersheds with IWSM practices than watersheds without. Thus, this study reviled that an introduction of these IWSM practices has a positive impact in improving soil-health. Moreover, IWSM practices implemented on dolerite geological formation showed a higher impact on soil-health as compared to management practices implemented on sandstone geological formation.

Taxi drivers: the role of animals in transporting mycorrhizal fungi.

Dispersal of mycorrhizal fungi via animals and the importance for the interacting partners' life history as well as for ecosystems is an understudied topic. In this review, we describe the available evidence and the most important knowledge gaps and finally suggest ways to gain the missing information. So far, 33 articles have been published proving a successful transfer of mycorrhizal propagules by animals. The vast majority of research on invertebrates was focused on arbuscular mycorrhizal (AM) fungi, whereas papers on vertebrates (mainly rodents and artiodactyls) equally addressed ectomycorrhizal (ECM) and AM fungi. Effective dispersal has been mostly shown by the successful inoculation of bait plants and less commonly by spore staining or germination tests. Based on the available data and general knowledge on animal lifestyles, collembolans and oribatid mites may be important in transporting ECM fungal propagules by ectozoochory, whereas earthworms, isopods, and millipedes could mainly transfer AM fungal spores in their gut systems. ECM fungal distribution may be affected by mycophagous dipterans and their hymenopteran parasitoids, while slugs, snails, and beetles could transport both mycorrhizal groups. Vertebrates feeding on fruit bodies were shown to disperse mainly ECM fungi, while AM fungi are transported mostly accidentally by herbivores. The important knowledge gaps include insufficient information on dispersal of fungal propagules other than spores, the role of invertebrates in the dispersal of mycorrhizal fungi, the way in which propagules pass through food webs, and the spatial distances reached by different dispersal mechanisms both horizontally and vertically.

Arbuscular mycorrhizal fungi affect total phenolic content and antimicrobial activity of Tamarix gallica in natural semi-arid Algerian areas

Polyphenolic compounds gained interest in the pharmaceutical research due to their beneficial bioactive compound for a healthy diet. Arbuscular mycorrhizal fungi (AMF) are known to interact with host plant metabolism, inducing accumulation of health-promoting phytochemicals and polyphenolic molecules. Tamarix gallica is a halophytic species having hepatotonic and stimulant properties. Leaf, flower and root infusion have anti-inflammatory and anti-diarrheic properties. The purpose of this study was to assess the presence and the diversity of arbuscular mycorrhizal fungi associated with T. gallica rhizosphere in Algerian steppic semi-arid site and to evaluate antimicrobial activities of leaf and root phenolic extracts. Four glomoid and one gigasporoid AMF spores type were isolated from rhizosphere of mycorrhizal Tamarix specimens. Total phenolic compounds were higher in roots than in leaves. Furthermore, T. gallica extracts showed significant antimicrobial properties against human pathogen bacterial strains. The mean inhibition zone was from 0 to 15 mm when concentration increased from 1 to 100 mg l−1. The highest significant activity for leave and root methanolic extracts was observed against Proteus mirabilis. Positive correlation was recorded between AMF root colonization and antimicrobial activity. Significant effect of plant type, soil characteristics and AMF root colonization on polyphenolic content was noticed. These findings highlight the complexity of T. gallica/AMF symbiosis and their effect on polyphenolic compounds and suggest that T. gallica inoculated with arbuscular mycorrhizal fungi may be considered as an interesting source of antioxidants for therapeutic or nutraceutical industries and for food manufactures.

ASSOCIATION OF ARBUSCULAR MYCORRHIZAL FUNGAL SPECIES IN THE PLANT SPECIES OF BARGUR HILLS, ERODE DISTRICT, TAMIL NADU, INDIA

The present study was carried out the arbuscular mycorrhizal fungal root colonization and spore population diversity some medicinal plants species at Bargur hills Western Ghats of (Anthyur taluk), Erode district, Tamil Nadu, India. Root and rhizosphere soil samples were collected during the month of August,2017-March, 2018 from the surface to 20 cm depth as well as pH were also measured. Totally 25 plant species belonging to 19 families recovered Arbuscular mycorrhizal fungal spore and root colonization. The results of the present study arbuscular mycorrhizal spore population in the rhizosphere soil and rootcolonization of all the plant species. A total of 22 AM fungal species belonging to 7 genera and 2 different orders were recorded from the rhizosphere soil samples of this study region. The Glomus was dominant had seen in rhizosphere soil samples in all the medicinal plant species. The maximum spore population was found in the rhizosphere soil samples of Leucas aspera (470 /100 g soil) which belongs to the family Lamiaceae and lowest spore population was observed in the Tephorosia purpurea (123 /100g soil) belongs to Fabaceae. The highest 83 % AM fungal infection was found in roots of Achyranthus aspera belongs to the family Amaranthaceae, while the lowest 23 % AM fungal association was found in the root of Mimosa pudica belongs to the family Mimosaceae.

The reproductive phenology of Acaena elongata and its relation with arbuscular mycorrhizal fungi

Plant sexual reproduction is an energetic process since it requires large amounts of resource allocation for flower and fruit production. Therefore, the establishment of a mutualism with arbuscular mycorrhizal (AM) fungi can increase the plant’s reproductive success. Acaena elongata is a native weed and a plant species indicator of anthropogenic perturbations in the understory of Abies religiosa forests of the Magdalena river basin in Mexico City. The aim of this work was to assess whether: i) there are temporal and spatial variations in AM fungal root colonization in A. elongata, ii) AM fungal root colonization is linked to A. elongata flower and fruit production patterns, and iii) AM fungal root colonization, spore abundance and richness, and A. elongata reproductive phenology are related to soil variables. Eight plots were established with five randomly selected individuals of A. elongata. Over the course of 1 year, the A. elongata reproductive phenology, environmental temperature, and relative soil moisture were registered monthly. Additionally, root samplings for AM fungal colonization and soil for determining the AM fungal spore abundance and richness were carried out during the rainy and dry seasons. The mean total AM fungal root colonization percentage was higher in the dry season (78 ± S.E. 11.09%) than in the rainy season (71 ± S.E. 13.2%); A. elongata showed reproductive structures throughout the year, with negative significant correlations between colonization and some phenological phases during the rainy season. Flower and fruit production as well as AM fungal root colonization were related to variations in the abiotic variables in each season and population. This study contributes to the understanding of the relationship between AM fungi and a plant species indicator of anthropogenic perturbations.

ASOSIASI FUNGI MIKORIZA ARBUSKULA (FMA) PADA BERBAGAI TINGGI SEMAI PERMUDAAN ALAM NYAMPLUNG ( Calophyllum inophyllum L) DI KABUPATEN KETAPANG

Nyamplung (Calophyllum inophyllum L) is known to be associated with AMF, but it is still unknown whether the association has begun to occur when cotyledons are still present or starting at a certain level of regeneration. Research has been done in Pecal Beach Kinjil River in Ketapang district. The purposes of the research are: (1) to assess the amount of spores and genus AMF associated with its development in the rhizosphere of nyamplung regeneration nature seedling stage from 10 cm to 150 cm, and (2) to determine root infection percentage in order to know the level of the association at any size of penage regeneration seedlings. The research is a field research by survey method with sampling technique against natural regeneration seedling level of 10 cm, 30 cm, 60 cm, 90 cm 120 cm, and 150 cm. The data was collectedin laboratoryon the form of the number of spores and genus AMF and the percentage of infections in the roots. The research results showed that there were 616 AMF spores fruit / 100 g of sandy soil consisting of the genus Glomus ( 597 pieces / 100 g sandy soil), Gigaspora ( 15 pieces / 100 g sandy soil) and Scutellospora ( 4 pieces / 100 g sandy soil). The development of the number of spores increased from the height of the seedling's natural regeneration measuring was 10 cm to 150 cm. The results of observations on the roots found thatAMF infection is in the form of vesicles and arbuscular. Infection at the root of natural penage regeneration from 84.44-100%, indicating the level of association between AMF and nyamplung seedling's natural regeneration in the high class ( grade 5 ) . Keywords: Arbuscular Mycorrhizal Fungi (AMF) Nyamplung (Calophyllum inophyllumL) Natural Seedling Regeneration, Pecal Beach

Nutritional status of KwaZulu-Natal soils affects microbe symbiosis, nitrogen utilization and growth of Vigna radiata (L.) R. Walczak

A major driving force behind sustainable agriculture and protection of the environment is effective management of nitrogen (N) in farming. Better understanding on the growth and functional adaptation of legumes under low nutrient savannah and grassland ecosystems remain crucial for food security. Therefore, this study examined if Vigna radiata (L.) R. Wilczek (Mung bean) establishes multiple symbiosis with soil microbes in KwaZulu-Natal (KZN) soils and how that symbiosis affects plant N nutrition and related-carbon growth costs. The study was conducted in the greenhouse using soils from four (Hluhluwe, Izingolweni, Bergville, and Ashburton) different geographical areas of KZN province. The soils were used as a natural inoculum and growth substrate thus treated as four treatments. Soil analysis of the four geographical areas showed marked differences with regard to phoshorus (P) and potassium (K) nutrient concentrations, exchange acidity and arbuscular mycorrhizal (AM) spore counts, while no significant differences were observed among the four treatments in term of N concentration and root colonization. Soils from the four sites were acidic and showed variation in nutrients especially with regard to P and N. Bergville soils had the highest P concentrations, exchange acidity and AM fungi spore counts, while Hluhluwe soils had the highest concentration of K, total cations and lowest spore count. Vigna radiata grown in Hluhluwe soils had higher biomass when compared to Bergville soil-grown plants. All plants nodulated with the exception of plants that were grown with Bergville soil. Despite differences in soil nutrient concentration, V. radiata plants established symbiosis with AM fungi, Rhizobium and numerous Bacillus species. Furthermore, the legume plants including the non-nodulated Bergville-grown V. radiata plants were able to switch N sources (atmospheric and soil N) to maintain their N nutrition and carbon construction costs. This observation suggests that non-nodulated Bergville-grown plants may have established symbiosis with other bacterial taxa such as Bacillus spp. and other endophytic bacterial spp. that fix atmospheric N. Overall, the symbiotic association of V. radiata with Rhizobium, AM fungi and various Bacillus species enhanced N utilization. In addition, V. radiata has the capacity to switch between soil N and atmospheric N while maintaining low carbon construction cost under low soil nutrient conditions. Vigna radiata thus can be adaptable to low soil nutrient savannah and grassland ecosystems in KZN province, South Africa.