Arbuscular mycorrhizal propagules in soils from a tropical forest and an abandoned cornfield in Quintana Roo, Mexico: visual comparison of most-probable-number estimates

Savannas growing on stony, old and nutrient-poor soils of southern Venezuela were severely disturbed by removal of the soil organic layers with bulldozers for road building. Introduced species Brachiaria decumbens, Brachiaria humidicola, Pueraria phaseoloides, and Calopogonium sp. were sown. The substrate was fertilized and limed. Plant cover, vesicular – arbuscular mycorrhizae colonization, spore number, and most probable number of propagulels in undisturbed savanna, disturbed nonrevegetated savanna, and six revegetated savannas were assessed. The perturbation reduced the mycorrhizal propagule number in comparison with the undisturbed savanna. In the nonrevegetated areas the mean percent ground cover 2 years after disturbance was low (0.04%). In revegetated areas an increase in mycorrhizal propagule number occurred and the mycorrhizal colonization of the sown species was high. In restored areas there was an increase in species of nonmycotrophic Amaranthaceae. The results support other predictions on the mycorrhizae in successional biomes, because in the extremely nutrient-poor soils studied the colonizing species were mainly mycotrophic. The reclamation program applied in disturbed areas was useful because it has allowed the recovery of vesicular – arbuscular mycorrhizal inoculum and there was an increase in the recolonization of native plants. Key words: disturbance, endomycorrhizae, revegetation, savanna, vesicular – arbuscular mycorrhizae.

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Efecto de dos abonos orgánicos en las cadenas tróficas del suelo cultivado con mora

Agronomía Mesoamericana ◽

10.15517/ma.v28i3.25861 ◽

2017 ◽

Vol 28 (3) ◽

pp. 619

Author(s):

Martha Orozco Aceves ◽

José Alonso Calvo Araya ◽

Jean Alexander Gamboa Tabares ◽

Wálter Peraza Padilla ◽

Orlando Varela Rodríguez ◽

...

Keyword(s):

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Biological Properties ◽

Organic Fertilizers ◽

Plate Count ◽

Most Probable Number ◽

Scaling Analysis ◽

San Jose ◽

Probable Number ◽

Buena Vista

Soil fertilization with organic fertilizers comprises a practice that improves the soil biological properties; however, the effect of these on the soil food web (SFW) has been scarcely studied. The aim of this study was to determine the effect of two commercial organic fertilizers on the structure of the SFW associated with roots of blackberry plants (Rubus adenotrichos). The research was conducted in two blackberry plantations located one in San Martín de León Cortés, and the other one in Buena Vista de Pérez Zeledón in San José, Costa Rica, from August to December, 2010. In the two plantations, plants were fertilized with compost or vermicompost. The roots of blackberry plants surrounding soil were sampled in order to quantify groups of the SFW through the following techniques: bacteria and filamentous fungi by plate count, protozoa by the most probable number, spores from arbuscular mycorrhizal fungi and nematodes by flotation-centrifugation, microarthropods, macroarthropods, and worms were directly counted in soil samples. The dataset was analyzed by multidimensional scaling analysis. The addition of organic fertilizers to soil caused a differential effect on the structure of the SFW (as compared with non-fertilized soils). The effect differed in soil from each of the experimental plantations according to fertilizer type. The groups of organisms mainly affected were actinomycetes and protozoa, which implies that the structure of SFW and consequently, the function of soil were not affected by the addition of organic fertilizers.

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Communities of arbuscular mycorrhizal fungi in maize (Zea mays L.) crops along an edaphoclimatic gradient in Northeast Brazil

Botany ◽

10.1139/cjb-2018-0084 ◽

2018 ◽

Vol 96 (11) ◽

pp. 767-778 ◽

Cited By ~ 2

Author(s):

Catarina Maria Aragão de Mello ◽

Gladstone Alves da Silva ◽

Fritz Oehl ◽

Iolanda Ramalho da Silva ◽

Inácio Pascoal do Monte Junior ◽

...

Keyword(s):

Species Richness ◽

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Zea Mays L ◽

Arbuscular Mycorrhizal ◽

Most Probable Number ◽

Probable Number ◽

Structural Differences ◽

Amf Communities ◽

Original Area

The objective of this study was to determine the species richness, diversity, and communities of arbuscular mycorrhizal fungi (AMF), based on the morphology of their spores, in maize plantations along an edaphoclimatic gradient going from a humid zone (original area of Atlantic rainforest), to a transition zone and a drier zone (original area of Caatinga), to increase the understanding of the ecology of AMF in tropical agroecosystems. We extracted glomerospores from soil samples from maize plantations in each mesoregion and analysed AMF propagules and community structure. A total of 57 AMF taxa were identified, of which two are new to science. The most probable number of AMF infective propagules did not differ among the three areas. A greater number of glomerospores was obtained from the transition site, whereas species richness for AMF differed between the high humidity and transition sites. The composition of AMF communities differed among sites, with edaphic attributes significantly associated with AMF community composition. The environmental conditions of each mesoregion contribute to the structural differences of AMF assemblages in soils cultivated by the same host plant (maize).

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Inoculation of citrus with root fragments containing chlamydospores of the mycorrhizal fungus Glomus intraradices

Canadian Journal of Botany ◽

10.1139/b86-233 ◽

1986 ◽

Vol 64 (8) ◽

pp. 1739-1744 ◽

Cited By ~ 8

Author(s):

J. H. Graham ◽

D. Fardelmann

Keyword(s):

Arbuscular Mycorrhizae ◽

Glomus Intraradices ◽

Mycorrhizal Fungus ◽

Arbuscular Mycorrhizal ◽

Most Probable Number ◽

Probable Number ◽

Vesicular Arbuscular ◽

Grass Root ◽

Colonization Potential ◽

Potting Media

The vesicular–arbuscular mycorrhizal fungus, Glomus intraradices, was found sporulating in citrus roots in an orchard soil. Dead root fragments of citrus accounted for a high proportion of the propagules in soil as measured by the most probable number technique. Sudan grass root fragments from pot cultures containing 7 and 94 chlamydospores of G. intraradices per milligram dry root had 11 and 184 (most probable number) propagules per milligram dry root, respectively. Inoculum densities of 20–40 mg of root fragments per 100 cm3 of potting media resulted in 100% inoculation success of Carrizo citrange grown from seed. A decrease in root fragment density to as low as 2.5 mg per 100 cm3 of medium reduced inoculation success and root colonization, but did not reduce growth and nutrient uptake by inoculated seedlings. The growth of vesicular–arbuscular mycorrhizal plants in a soilless medium amended with relatively insoluble rock phosphate was less than that of nonmycorrhizal plants fertilized with soluble phosphorus; copper uptake, however, was significantly increased by vesicular–arbuscular mycorrhizae. Root fragments stored up to 1 year under moist conditions did not lose colonization potential, whereas drying reduced colonization potential to near zero after 9 months.

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The 'most probable number' method for enumerating infective propagules of vesicular arbuscular mycorrhizal fungi in soil

Soil Research ◽

10.1071/sr9790515 ◽

1979 ◽

Vol 17 (3) ◽

pp. 515 ◽

Cited By ~ 240

Author(s):

WM Porter

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Large Population ◽

Arbuscular Mycorrhizal ◽

Most Probable Number ◽

Probable Number ◽

Vesicular Arbuscular ◽

Field Soils ◽

Wet Sieving ◽

Good Agreement

Estimates of the number of infective propagules of vesicular-arbuscular (VA) endophytes in two soils were obtained using a most probable number (MPN) method. These estimates were compared with counts of the number of spores in the same soils obtained using a conventional wet sieving method. In one soil, there was good agreement between the number of coarse endophyte propagules, estimated by the MPN technique, and the number of germinable spores extracted using the wet sieving technique. However, a large population of fine endophyte propagules (more than 230 per 50 g soil) could only be enumerated using the MPN technique. In the second soil, fewer coarse endophyte propagules were found using the wet sieving technique than when using the MPN technique. The MPN technique appears to give a more realistic estimate of the number of infective propagules of VA endophytes in field soils than the conventional method.

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

Revista Caatinga ◽

10.1590/1983-21252019v32n416rc ◽

2019 ◽

Vol 32 (4) ◽

pp. 995-1004

Author(s):

FELIPE FERREIRA DA SILVA ◽

THAINÁ ALVES DOS SANTOS ◽

EDERSON DA CONCEIÇÃO JESUS ◽

GUILHERME MONTANDON CHAER

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Base Material ◽

Arbuscular Mycorrhizal ◽

Most Probable Number ◽

Semiarid Region ◽

Oil Exploration ◽

Probable Number ◽

Gravel Mining ◽

The Impact

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.

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Total and faecal coliforms presence in cenotes of Cancun; Quintana Roo, Mexico

BIORISK – Biodiversity and Ecosystem Risk Assessment ◽

10.3897/biorisk.15.58455 ◽

2020 ◽

Vol 15 ◽

pp. 31-43

Author(s):

Jessica Borbolla-Vazquez ◽

Paul Ugalde-Silva ◽

José León-Borges ◽

Job Alí Díaz-Hernández

Keyword(s):

Water Quality ◽

Liquid Waste ◽

Quintana Roo ◽

Coliform Bacteria ◽

Most Probable Number ◽

Faecal Coliforms ◽

Probable Number ◽

Industrial Activities ◽

The Impact ◽

Dry And Rainy Seasons

The large increase in population in Cancun, Mexico has increased domestic, agricultural and industrial activities, resulting in inadequate solid and liquid waste management that can affect underground aquifers. One of the factors which affects water quality is coliform bacteria. The present study focused on determining the presence of total and faecal coliforms in ten urban cenotes in Cancun. Sampling was carried out in the dry and rainy seasons of 2018. The Most Probable Number (MPN) technique was used to determine the concentration of coliform bacteria. The results from the analyses indicate that the ten cenotes are contaminated with total and faecal coliforms. Additionally, the concentration of coliforms increases during the rainy season. We conclude that all the cenotes are contaminated with faecal coliforms and suggest that more studies are necessary to determine the origin of this contamination and the impact on the ecosystem.

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Factors affecting the estimation of numbers of infective propagules of vesicular arbuscular mycorrhizal fungi by the most probable number method

Soil Research ◽

10.1071/sr9830073 ◽

1983 ◽

Vol 21 (1) ◽

pp. 73 ◽

Cited By ~ 38

Author(s):

JM Wilson ◽

MJ Trinick

Keyword(s):

Arbuscular Mycorrhizal Fungi ◽

Mycorrhizal Fungi ◽

Arbuscular Mycorrhizal ◽

Most Probable Number ◽

Probable Number ◽

Vesicular Arbuscular Mycorrhizal Fungi ◽

Factors Affecting ◽

Soil Inoculum ◽

Vesicular Arbuscular ◽

Time Of Harvest

Factors affecting the estimation of the number of infective propagules of vesicular arbuscular mycorrhizal fungi by the most probable number (MPN) method were investigated. The value obtained was shown to be dependent on the conditions of the experiment. Both temperature and time of harvest changed the result because of their effects on the growth of both roots and propagules, and hence on their interception. Other factors which must be taken into account in order to optimize the MPN estimate are discussed. The number of infective propagules in a dried root/soil inoculum was shown to be affected by both the amount of infection in the pot culture from which it was formed and by its age.

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Analysis of Coliform and Colifecal Total Pollution Test on Various Types of Drinking Water Using the MPN (Most Probable Number) Method

Serambi Journal of Agricultural Technology ◽

10.32672/sjat.v2i2.2416 ◽

2020 ◽

Vol 2 (2) ◽

Author(s):

Wanda Aulya ◽

Fadhliani Fadhliani ◽

Vivi Mardina

Keyword(s):

Drinking Water ◽

Fecal Coliform ◽

Pathogenic Bacteria ◽

Microbiological Quality ◽

Coliform Bacteria ◽

Most Probable Number ◽

Inspection Method ◽

Sample Number ◽

Probable Number ◽

Fecal Coliform Bacteria

Water is the main source for life and also the most severe substance caused by pollution. The mandatory parameters for determining microbiological quality of drinking water are total non-fecal Coliform bacteria and Coliform fecal (Escherichia coli). Coliform bacteria are a group of microorganisms commonly used as indicators, where these bacteria can be a signal to determine whether a water source has been contaminated by bacteria or not, while fecal Coliform bacteria are indicator bacteria polluting pathogenic bacteria originating from human feces and warm-blooded animals (mammals) . The water inspection method in this study uses the MPN (Most Probable Number) method which consists of 3 tests, namely, the presumption test, the affirmation test, and the reinforcement test. The results showed that of 15 drinking water samples 8 samples were tested positive for Coliform bacteria with the highest total bacterial value of sample number 1, 15 (210/100 ml), while 7 other samples were negative. From 8 positive Coliform samples only 1 sample was stated to be negative fecal Coliform bacteria and 7 other samples were positive for Coliform fecal bacteria with the highest total bacterial value of sample number 1 (210/100 ml).

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Cemaran Eshericia coli dalam makanan laut yang beredar di pasar tradisional Kota Pontian

Jurnal Kesehatan Khatulistiwa ◽

10.26418/jurkeswa.v1i1.42974 ◽

2015 ◽

Vol 1 (1) ◽

pp. 44

Author(s):

Rafika Sari ◽

Pratiwi Apridamayanti

Keyword(s):

Most Probable Number ◽

Probable Number

Latar Belakang: Makanan laut merupakan salah satu jenis makanan yang banyak dikonsumsi oleh masyarakat selain sebagai komoditi ekspor. Mengkonsumsi makanan laut yang telah terkontaminasi bakteri hidup atau toksin yang dihasilkannya dapat menyebabkan keracunan makanan. Tujuan penelitian ini adalah untuk mengetahui adanya kontaminasi bakteri koliform E.coli sebagai indikator pencemaran pada makanan laut dan memberikan informasi kelayakan dan keamanan konsumsi dari makanan laut di dua pasar tradisional terbesar di daerah Pontianak. Metode: Sampel yang digunakan adalah ikan, sotong dan udang. Penelitian terhadap sampel dilakukan menggunakan uji Most Probable Number (MPN) yang dilengkapi dengan uji biokimia untuk mengidentifikasi jenis bakteri pada sampel melalui penanaman bakteri pada media agar Lactose Broth (LB) dan Briliant Green Lactose Bile Broth (BGLB). Hasil: Hasil penelitian menunjukkan bakteri koliform E.coli terdeteksi pada 100% sampel dengan nilai MPN yang tidak memenuhi kriteria kelayakan konsumsi, yakni >3/g. Kesimpulan: Makanan yang ada tidak memenuhi kriteria kelayakan konsumsi.

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