Percentage Of Arbuscular Mycorrhizal Fungi Colonization Research Articles

Arbuscular mycorrhizal colonization of pioneer mangrove species in Mahakam Delta, East Kalimantan

Arbuscular mycorrhizal fungi (AMF) are symbiotic, with more than 80% of plant species in terrestrial and mangrove ecosystems. This study aimed to determine the level of AMF colonization on Avicennia lanata and its correlation with soil chemical properties. Sampling was conducted in Sepatin Village, located in Mahakam Delta. There are four sampling locations, three were mangrove rehabilitation areas (A, B, and C), and one was a mangrove natural forest (MNF). Root samples were taken from four A. lanata seedlings purposively selected at each location. The roots were stained with 0.05% trypan blue, and the mycorrhizal structures of the roots were observed using a compound microscope. The results showed that the percentage of AMF colonization with A. lanata in MNF was higher (97%) than in other locations. Internal hyphae were the dominant structure found in the root of A. lanata in all locations, with a percentage of 76.61%. AMF root colonization negatively correlated with N-total, C-organic, and available P. In contrast, Ca, Mg, K, Na, and CEC positively correlated with AMF root colonization. The colonization of AMF in the root of A. lanata may promote the early growth of seedlings, and the application of AMF can support rehabilitating mangrove degraded.

Edaphic factors and elevation gradient influence arbuscular mycorrhizal colonization and spore density in the rhizosphere of Shorea robusta Gaertn

Arbuscular mycorrhizal fungi (AMF) are important ecosystem engineers that improve nutrient uptake and help plants adapt to a variety of abiotic stresses. Few studies have examined the relationship between AMF and a specific host tree along an elevation gradient. Shorea robusta is the dominant tree species in Nepal's tropical forests, with very high timber value. The goal of this study was to ascertain how edaphic factors and elevation gradient influence AMF colonization and spore density within the rhizosphere of Shorea robusta. The present study was conducted in four S. robusta dominated forests ranging from 82 m to 950 m asl. Among the four forests, Tarai Sal forest (TSF); Bhabar Sal forest (BSF) belonged to lower elevation Sal forest and Plateau Sal forest (PSF); Hill Sal forest (HSF) belonged to high elevation Sal forest. The percentage of AMF colonization and soil spore density were assessed by magnified intersect method and wet sieving and decanting method respectively. The edaphic factors viz. organic matter, nitrogen, phosphorous, potassium, pH, soil temperature, bulk density, moisture content, and water holding capacity of soil were determined by standard methods. Total AMF colonization ranged from 33% to 57%. Spore density, on the other hand, ranged from 25 to 366 per 100 g of soil. The maximum AMF root colonization and spore density for lower elevation Sal forest was 52% and 39/100 g of soil respectively while that for higher elevation Sal forest was 57% and 366/100 g of soil respectively. Pearson's correlation test revealed that total AMF colonization as well as spore density in the rhizosphere of S. robusta were affected by phosphorus content, pH, moisture content, water-holding capacity, soil temperature, and elevation. Moreover, the spore density was also affected by nitrogen content. Total AMF colonization and spore density were found to be highly correlated. Overall, the intensity of AMF colonization and spore density were higher in higher elevation Sal forest compared to the lower elevation Sal forest. This study can be used to gain insights into the active involvement of AMF in the sustainable management of the forest ecosystem.

Cover Crops Modulate the Response of Arbuscular Mycorrhizal Fungi to Water Supply: A Field Study in Corn.

Cover crops (CCs) were found to improve soil health by increasing plant diversity and ground cover. They may also improve water supply for cash crops by reducing evaporation and increasing soil water storage capacity. However, their influence on plant-associated microbial communities, including symbiotic arbuscular mycorrhizal fungi (AMF), is less well understood. In a corn field trial, we studied the response of AMF to a four-species winter CC, relative to a no-CC control, as well as to two contrasting water supply levels (i.e., drought and irrigated). We measured AMF colonization of corn roots and used Illumina MiSeq sequencing to study the composition and diversity of soil AMF communities at two depths (i.e., 0-10 and 10-20 cm). In this trial, AMF colonization was high (61-97%), and soil AMF communities were represented by 249 amplicon sequence variants (ASVs) belonging to 5 genera and 33 virtual taxa. Glomus, followed by Claroideoglomus and Diversispora (class Glomeromycetes), were the dominant genera. Our results showed interacting effects between CC treatments and water supply levels for most of the measured variables. The percentage of AMF colonization, arbuscules, and vesicles tended to be lower in irrigated than drought sites, with significant differences detected only under no-CC. Similarly, soil AMF phylogenetic composition was affected by water supply only in the no-CC treatment. Changes in the abundance of individual virtual taxa also showed strong interacting effects between CCs, irrigation, and sometimes soil depth, although CC effects were clearer than irrigation effects. An exception to these interactions was soil AMF evenness, which was higher in CC than no-CC, and higher under drought than irrigation. Soil AMF richness was not affected by the applied treatments. Our results suggest that CCs can affect the structure of soil AMF communities and modulate their response to water availability levels, although soil heterogeneity could influence the final outcome.

Carbohydrate and lipid balances in the positive plant phenotypic response to arbuscular mycorrhiza: increase in sink strength.

The exchange of phosphorus (P) and carbon (C) between plants and arbuscular mycorrhizal fungi (AMF) is a major determinant of their mutualistic symbiosis. We explored the C dynamics in tomato (Solanum lycorpersicum) inoculated or not with Rhizophagus irregularis to study their growth response under different NaH2 PO4 concentrations (Null P, 0 mM; Low P, 0.065 mM; High P, 1.3 mM). The percentage of AMF colonization was similar in plants under Null and Low P, but severely reduced under High P. However, the AMF mass biomarker 16:1ω5 revealed higher fungal accumulation in inoculated roots under Low P, while more AMF spores were produced in the Null P. Under High P, AMF biomass and spores were strongly reduced. Plant growth response to mycorrhiza was negative under Null P, showing reduction in height, biovolume index, and source leaf (SL) area. Under Low P, inoculated plants showed a positive response (e.g., increased SL area), while inoculated plants under High P were similar to non-inoculated plants. AMF promoted the accumulation of soluble sugars in the SL under all fertilization levels, whereas the soluble sugar level decreased in roots under Low P in inoculated plants. Transcriptional upregulation of SlLIN6 and SlSUS1, genes related to carbohydrate metabolism, was observed in inoculated roots under Null P and Low P, respectively. We conclude that P-limiting conditions that increase AMF colonization stimulate plant growth due to an increase in the source and sink strength. Our results suggest that C partitioning and allocation to different catabolic pathways in the host are influenced by AMF performance.

New Record of Arbuscular Mycorrhizal Fungi (AMF) Association with Kebar Grass (<i>Biophytum petersianum</i> Klotzsch.) in the Grassland Area of Kebar, Tambrauw Regency, West Papua, Indonesia

Arbuscular mycorrhizal fungi (AMF) are an important form of symbiosis between fungi and plants in an ecosystem. One of the medicinal plants used by the people in West Papua is kebar grass (Biophytum petersianum Klotzsch.). This study aims to determine the AMF association in the rhizosphere of B. petersianum in grasslands. Survey method was used in this study. The presence of AMF was observed by examining root colonization and spore diversity. The results showed that the percentage of AMF colonization in roots was between 46.7–90.0% with an average of 71.66%. Meanwhile, the number of spores found in the plant rhizosphere averaged 119.8 spores per 10 grams of soil sample. There were 18 species of AMF dominated by the genus Glomus (7 species), Acaulospora (3 species), while the genus Claroideoglomus, Entrophospora, Gigaspora, and Scutellospora were dominated each with 2 species. This finding is the first record on the presence of AMF on B. petersianum in West Papua.

Use of the arbuscular mycorrhizal fungus Glomus intraradices as biological control agent of the nematode Nacobbus aberrans parasitizing tomato

ABSTRACT The plant-parasitic nematode Nacobbus aberrans is an endoparasite that induces gall formation in the roots and causes severe losses to diverse crops. Some populations of this nematode show preference for certain hosts, revealing the existence of “races/groups” with diff erent behaviour and making nematode management difficult. A possible biological control alternative to reduce the damage caused by this species may be the use of arbuscular mycorrhizal fungi (AMF). In the present work, the effect of Glomus intraradices on tomato plants inoculated with the nematode at transplanting and three weeks later was tested. At 60 days, the following parameters were estimated: percentage of AMF colonization, root and aerial dry weight, number of galls and egg masses, and reproduction factor (RF=final population/initial population) of N. aberrans . AMF colonization was higher in the presence of the nematode. The use of AMF favoured tomato biomass and reduced the number of galls and RF on the plants inoculated with the nematode at transplanting. Key words: arbuscular mycorrhiza, false root-knot nematode, microbiological control, plant protection

Arbuscular mycorrhizal fungi associated with the rhizosphere of seedlings and mature trees of Swietenia macrophylla (Magnoliophyta: Meliaceae) in Los Tuxtlas, Veracruz, Mexico

BackgroundBig-leaf mahogany (Swietenia macrophylla King) is the woody species with the highest economic value in Latin America. Currently, it is subject to intensive exploitation, diminishing its natural populations. Due to this decline, the species is a preferred species for reforestation and establishment of commercial tropical plantations. Mycorrhizal symbiosis is a biotic factor scarcely studied in the ecology of this species. Therefore, the objective of this research was to identify the diversity of arbuscular mycorrhizal fungi (AMF) species associated with the rhizosphere of seedlings and mature trees of big-leaf mahogany growing in its natural habitat, a tropical rain forest in Los Tuxtlas, Veracruz, Mexico. Soil samples from a 20-cm depth were taken from the rhizosphere of big-leaf mahogany seedlings and mature trees. Additionally, spores from the rhizosphere soil were propagated on Sorghum vulgare, isolated and identified. The percentage of AMF colonization was also evaluated.ResultsTwenty-three AMF morphospecies belonging to four genera were registered: 11 corresponded to Glomus, 10 to Acaulospora, one to Gigaspora and one to Ambispora. Ambispora gerdemannii , Acaulospora spinosa, A. scrubiculata, A. foveata, Septoglomus constrictum, Claroideoglomus etunicatum, Glomus tenebrosum , Sclerocystis sinuosum, Diversispora aurantium, and Rhizophagus fasciculatus were identified to species level. We report for first time the presence of G. tenebrosum and C. etunicatum in natural areas of the humid Mexican tropics. The rhizosphere soil of the trees harbor more morphospecies than soil from seedlings (21 and 11 morphospecies, respectively). Sorghum plants inoculated with rhizosphere soil from big-leaf trees showed higher percentages of total mycorrhizal colonization, arbuscules and hyphae (P < 0.01) compared with plants inoculated with rhizosphere soil from seedlings.ConclusionsTwenty-three AMF morphospecies included in the genera Glomus, Acaulospora, Gigaspora and Ambispora were found associated with rhizosphere soil of mahogany trees growing in its natural habitat. The diversity of AMF genera and species found was around two times greater in mature trees than in seedlings. Some AMF species were only detected when trap-plants culture methods were employed, stressing the importance of this technique. This information has great potential for biotechnological application when performing reintroductions or reforestation with the tropical tree mahogany.

Coal Waste Powder Amendment and Arbuscular Mycorrhizal Fungi Enhance the Growth of Jabon (Anthocephalus cadamba Miq) Seedling in Ultisol Soil Medium

Coal powder waste application on low nutrient media is expected to be able to increase plant growth and to improve Arbuscular mycorrhizal fungi (AMF) development. The objective of this research was to determine the effect of coal waste powder on the growth of Anthocephallus cadamba Jack and AMF development grown on ultisol soil. Two factors in a completely randomised experimental design was conducted under greenhouse conditions and Duncan Multiple Range Test was used to analyse of the effect the treatment. The first factor was ultisol soil ammended with coal waste powder (control, soil amanded with coal waste 5%, soil amanded with coal waste 10% and soil amanded with coal waste 15%) and the second factor was AMF inoculation (uninoculated control, inoculated with Gigaspora margarita). Plant height, diameter, shoot dry weight, percentage of AMF colonization and nutrient uptake were measured in this experiment. Results of this study showed that coal amendment and AMF when applied separately significantly increased height, diameter, shoot dry weight, root dry weight and nutrient uptake of 12 weeks A. cadamba seedling, but when the coal waste powder and AMF were combined the plant growth parameters were lower than those applied separately but significantly higher than control. The application of coal waste powder or AMF in ultisol soil could increase A. cadamba growth and development.[How to Cite : Budi SW and F Christina. 2013. Coal Waste Powder Amendment and Arbuscular Mycorrhizal Fungi Enhance the Growth of Jabon (Anthocephalus cadamba Miq) Seedling in Ultisol Soil Medium. J Trop Soils, 18 (1): 59-66. doi: 10.5400/jts.2013.18.1.59][Permalink/DOI: www.dx.doi.org/10.5400/jts.2013.18.1.59]

Effect of the arbuscular mycorrhizal fungus Glomus intraradices on the false root-knot nematode Nacobbus aberrans in tomato plants

Information about the interaction between arbuscular mycorrhizal fungi (AMF) and the false root-knot nematode Nacobbus aberrans (Thorne, 1935) Thorne & Allen, 1944 is scarce. The effect of Glomus intraradices Schenk & Smith on tomato (Lycopersicon esculentum L.) cv. Platense inoculated with nematode juveniles from Lisandro Olmos (Argentina) was studied under greenhouse conditions. Six treatments with five replications were performed. After 80 days, nematode reproduction and percentage of AMF colonization in roots were estimated. Some plant growth parameters were also measured. In general, plants with AMF and AMF plus nematodes grew as well as the control without AMF and without nematodes. Furthermore, G. intraradices was beneficial in reducing nematode-induced damage in roots (lower number of galls) as well as in having a suppressive effect on parasite reproduction. This is the first study on the use of G. intraradices as a possible strategy in the control of N. aberrans in tomato.

Efecto de parametros físicos, químico y salinidad sobre la densidad poblacional y la colonización de micorrizas arbusculares en pasto angleton en el municipio de tolu, sucre, Colombia

El presente estudio tuvo como objetivo determinar el efecto de parámetros físicos, químico y salinidad sobre la densidad poblacional y la colonización de hongos formadores de micorrizas arbusculares (HMA) en pasto angletón en el municipio de Tolú, departamento de Sucre, Colombia. Se seleccionaron aleatoriamente 35 fincas ganaderas sembradas con la especie de pasto angletón, en ellas se tomaron muestras de suelo y de rizosfera a las cuales se realizaron análisis físicoquímico, de salinidad y microbiológico de HMA (número de esporas en 100 g de suelo y porcentaje de colonización en raíces). Las variables independientes asociadas a parámetros físicos, químico y de salinidad encontradas en el suelo fueron relacionadas con el número de espora y el porcentaje de colonización de HMA mediante análisis estadísticos que permitieran establecer relación directa entre ellas. Fueron encontrados modelos matemáticos, que relacionaron la densidad poblacional de espora de HMA y el porcentaje de colonización en raíces con parámetros físicos-químicos y de salinidad de los suelos. Este es el primer estudio que muestra la relación directa que existe entre parámetros físicos, químicos y de salinidad en función de la esporulación y la colonización de HMA en condiciones de suelos de fincas ganaderas perteneciente al municipio de Tolú en el departamento de Sucre.

Propágulos de fungos micorrízicos arbusculares em solos deficientes em fósforo sob diferentes usos, da região semi-arida no nordeste do Brasil

A conversão de áreas de caatinga em agricultura e pecuária de subsistência é uma das características marcantes da região semi-árida do Nordeste do Brasil. O presente estudo investigou o efeito dessa conversão sobre os propágulos de fungos micorrízicos arbusculares (FMA) em 10 locais diferentes, distribuídos nos Estados da Paraíba e de Pernambuco. Cada local consistiu de uma área de vegetação nativa (caatinga) contígua com uma área cultivada, na mesma posição de encosta. Amostras de solo foram coletadas a intervalos de 20-30 m, nas profundidades de 0-7,5 e 7,5-15 cm (10 locais x 2 usos do solo x 2 profundidades com 4 pontos amostrais) ao longo de uma transecção que cruzava as áreas contíguas. As raízes (&lt; 2 mm) catadas das amostras de solo (n = 160) foram coloridas com azul de tripan para quantificar o grau de colonização por FMA, verificando-se também o tipo de estruturas fúngicas presentes. Esporos de FMA extraídos do solo por peneiramento úmido foram incubados em solução de cloreto de iodonitrotetrazólio (INT) e contados, considerando-se viáveis os corados pelo INT. O solo foi analisado quanto ao teor de P-resina e CO total (COT). Para análise dos resultados, as 10 áreas com vegetação nativa foram separadas em dois subgrupos: caatinga preservada (CaatP, n = 6) e caatinga raleada (CaatR, n = 4), por apresentarem diferentes graus de degradação. Pelo mesmo motivo, as áreas cultivadas também foram separadas em dois subgrupos: cultivada preservada (CultP, n = 4) e cultivada degradada (CultD, n = 6). Dessa forma, foram estabelecidos quatro níveis de intensidade de uso do solo ou degradação, conforme o histórico de uso, a observação visual da degradação da vegetação ou do solo e a erosão do solo avaliada pela técnica do 137Cs. O efeito da intensidade de uso do solo nos propágulos de FMA somente foi observado na camada de 0-7,5 cm, exceto para esporos não-viáveis. A densidade de esporos viáveis variou de 1,4 a 6,8 esporos/50 g de solo e a de não-viáveis, de 91,4 a 226 esporos/50 g de solo. A categoria CaatR foi a que apresentou resultados mais consistentes em relação ao estímulo do desmatamento seletivo (raleamento) sobre os propágulos, com maior número de esporos viáveis, maior intensidade de colonização e diminuição da proporção de amostras com vesículas, em relação às demais categorias. Os teores de P-resina nas amostras de solo foram, em geral, muito baixos (&lt; 6 mg kg-1), tendo-se observado que a colonização radicular em amostras com teores inferiores a 1,5 mg kg-1 foi menos intensa naquelas com P-resina acima desse valor. Observou-se também que a colonização das raízes foi favorecida pelos teores mais altos de COT, o mesmo acontecendo com o número de esporos viáveis.