Relationship of mycorrhizal activity to time following reclamation of surface mine land in western Kentucky. I. Propagule and spore population densities

1996 ◽  
Vol 74 (2) ◽  
pp. 247-261 ◽  
Author(s):  
Ann B. Gould ◽  
James W. Hendrix ◽  
Richard S. Ferriss
Keyword(s):  
Mycorrhizal Fungi ◽  
Most Probable Number ◽  
Edaphic Factors ◽  
Population Densities ◽  
Surface Mine ◽  
Probable Number ◽  
Spore Population ◽  
Mine Sites ◽  
Highly Correlated ◽  
Western Kentucky

The relationships between estimates of mycorrhizal activity, time following reclamation, and soil edaphic factors were investigated over a period of 2.5 years during reclamation of five abandoned surface mine sites in western Kentucky. These sites were reclaimed at different times and were in varying stages of revegetation. At the seeding stage of reclamation and soon thereafter, propagule and spore population densities were low but invariably present. Roots recovered from minespoil during this period were not colonized, and colonization was not observed until a full year following reclamation. During the first 2 years following reclamation, colonization of roots, population densities of propagules and spores, and total spore volume increased rapidly. Thereafter, vegetative and mycorrhizal parameters appeared to stabilize. Each estimate of mycorrhizal activity in minespoil was highly correlated with time following reclamation and all other mycorrhizal parameters. Edaphic factors with positive relationships to mycorrhizal propagule and spore population densities included soil organic matter and calcium. Keywords: Glomales mycorrhizal fungi, reclamation, abandoned minespoil, most probable number, propagule population density.

Atrazine mineralisation in New Zealand topsoils and subsoils: influence of edaphic factors and numbers of atrazine-degrading microbes

Soil Research ◽  
1998 ◽  
Vol 36 (4) ◽  
pp. 557 ◽  
Author(s):  
Graham Sparling ◽  
Robert Dragten ◽  
Jackie Aislabie ◽  
Rhonda Fraser
Keyword(s):  
New Zealand ◽  
Moisture Content ◽  
Cation Exchange Capacity ◽  
Surface Soil ◽  
Exchange Capacity ◽  
Most Probable Number ◽  
Edaphic Factors ◽  
Decomposition Rates ◽  
Decomposition Products ◽  
Probable Number

The mineralisation of 14C-ring-labelled atrazine to 14CO2 was measured in 3 contrasting New Zealand soils under controlled conditions of temperature and moisture. The numbers of atrazine-degrading organisms were measured by a most probable number technique. Decomposition rates were slow, with a maximum of 41% of atrazine being mineralised over 263 days. Mineralisation was generally very low in subsoils and was much reduced by low moisture content. However, one subsoil from 60–90 cm depth had unusually high numbers of atrazine-degrading microbes and showed mineralisation greater than or equivalent to the surface soil. Mineralisation was approximately doubled by a 10°C rise in temperature over the range 16–28°C. In general, the rate of atrazine mineralisation over 7–96 days could be predicted from the number of atrazine-degrading microbes and the cation exchange capacity of the soil (R2 = 0·86). A large amount (54–77%) of 14C remained in the soil as non-extractable residues after 263 days, but only trace amounts of the added atrazine or the decomposition products de-ethyl atrazine and de-isopropyl atrazine were detected by extraction in organic solvent.

scholarly journals Evaluation of Two Direct Plating Methods Using Nonradioactive Probes for Enumeration of Vibrio parahaemolyticus in Oysters

2001 ◽  
Vol 67 (2) ◽  
pp. 721-724 ◽  
Author(s):  
J. A. Gooch ◽  
A. DePaola ◽  
C. A. Kaysner ◽  
D. L. Marshall
Keyword(s):  
Vibrio Parahaemolyticus ◽  
Most Probable Number ◽  
Mobile Bay ◽  
Probable Number ◽  
Direct Plating ◽  
Hemolysin Gene ◽  
Highly Correlated ◽  
Species Specific ◽  
Labeled Probe ◽  
Zero Time

ABSTRACT Oysters (Crassostrea virginica) were collected monthly from May 1998 to April 1999 from Mobile Bay, Ala., and analyzed to determine Vibrio parahaemolyticus densities at zero time and after 5, 10, and 24 h of postharvest storage at 26°C. After 24 h of storage at 26°C, oysters were transferred to a refrigerator at 3°C and then analyzed 14 to 17 days later. TheV. parahaemolyticus numbers were determined by the most-probable-number procedure using alkaline phosphatase-labeled DNA probe VPAP, which targets the species-specific thermolabile hemolysin gene (tlh), to identify suspect isolates (MPN-VPAP procedure). Two direct plating methods, one using a VPAP probe (Direct-VPAP) and one using a digoxigenin-labeled probe (Direct-VPDig) to identify suspect colonies, were compared to the MPN-VPAP procedure. The results of the Direct-VPAP and Direct-VPDig techniques were highly correlated (r = 0.91), as were the results of the Direct-VPAP and MPN-VPAP procedures (r = 0.91). The correlation between the Direct-VPDig and MPN-VPAP results was 0.85. The two direct plating methods in which nonradioactive DNA probes were used were equivalent to the MPN-VPAP procedure for identification of totalV. parahaemolyticus, and they were more rapid and less labor-intensive.

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

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.

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

Botany ◽  
2018 ◽  
Vol 96 (11) ◽  
pp. 767-778 ◽  
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).

Comparison of the SimPlate™ Total Plate Count Method with Petrifilm™, Redigel™, and Conventional Pour-Plate Methods for Enumerating Aerobic Microorganisms in Foods

1998 ◽  
Vol 61 (1) ◽  
pp. 14-18 ◽  
Author(s):  
L. R. BEUCHAT ◽  
F. COPELAND ◽  
M. S. CURIALE ◽  
T. DANISAVICH ◽  
V. GANGAR ◽  
...  
Keyword(s):  
Food Samples ◽  
Test Methods ◽  
Plate Count ◽  
Most Probable Number ◽  
Suitable Alternative ◽  
Probable Number ◽  
Plate Count Agar ◽  
Total Plate Count ◽  
Wide Range ◽  
Highly Correlated

The SimPlate™ Total Plate Count (TPC) method, developed by IDEXX Laboratories, Inc., is designed to determine the most probable number of aerobic microorganisms in foods. The 24-h test was compared to the conventional plate count agar (PCA) method, the Petrifilm™ Aerobic Count plates, and the Redigel™ Total Count procedure for enumerating microflora in 751 food samples. Results using the SimPlate™ TPC method were highly correlated (r ≥ 0.96) with results from other test methods. Slopes (0.96–0.97) were not significantly different from 1, and y intercepts (−0.03–0.08) were not different from 0. The SimPlate™ has a high counting range (> 1600 most probable number per single dilution), thus requiring fewer dilutions of samples compared to other methods evaluated. Some foods, e.g., raw liver, wheat flour, and nuts, contain enzymes that gave false-positive reactions on SimPlates™. Overall, however, the SimPlate™ TPC method is a suitable alternative to conventional PCA, Petrifilm™, and Redigel™ methods for estimating populations of mesophilic aerobic microorganisms in a wide range of foods.

Comparison of Different Most-Probable-Number Methods for Enumeration of Listeria in Poultry

2003 ◽  
Vol 66 (1) ◽  
pp. 65-71 ◽  
Author(s):  
ROSA CAPITA ◽  
CARLOS ALONSO-CALLEJA
Keyword(s):  
High Sensitivity ◽  
Single Step ◽  
Plate Count ◽  
Most Probable Number ◽  
Step Method ◽  
Predictive Values ◽  
Probable Number ◽  
Enrichment Broth ◽  
Test Taking ◽  
Highly Correlated

To estimate levels of Listeria spp. in poultry and to select the most appropriate enumeration method for routine analysis, 40 naturally contaminated retail chicken carcasses were tested in Ponferrada (León, N.W. Spain) using the direct plate count technique and various most-probable-number (MPN) designs (UVM I [University of Vermont modified Listeria enrichment broth], Fraser enrichment broth, or both were used in 3-, 5-, and 10-tube MPN techniques). MPN estimation was obtained from the number of tubes with Listeria confirmed (after streaking on PALCAM and modified Oxford agars: “true” MPN) and from the number of dark Fraser broth tubes (“predictive” MPN). Samples were analyzed in duplicate. Low levels of Listeria were found (<110 CFU/g). The direct plate count technique was totally ineffective for enumerating Listeria in poultry. The single-step (UVM I) and the two-step (UVM I-Fraser) MPN methods gave comparable estimations and a low number of significantly discrepant predictions. Using a single-step method with Fraser broth, lower true MPNs were obtained. The number of tubes used (3, 5, or 10) did not have a substantial influence on the results. Similar estimations, highly correlated (r = 0.538 to 0.968; P < 0.001), were found with (true MPN) and without (predictive MPN) plating confirmation when using the two-step MPN method. The statistical evaluation of the differential character of Fraser broth as part of the two-step MPN method showed high sensitivity (87.5 to 92.5%), specificity (95.2 to 98.6%), efficiency (94.2 to 97.6%), and predictive values (73.6 to 89.9% for a positive test and 98.0 to 98.9% for a negative test). Taking into account these results, we suggest the convenience of using a 3- or 5-tube two-step (UVM I-Fraser) MPN method with estimations obtained from the number of tubes with darkening, without confirmation, in order to achieve great savings in time and money.

Relationship of mycorrhizal activity to time following reclamation of surface mine land in western Kentucky. II. Mycorrhizal fungal communities

1998 ◽  
Vol 76 (2) ◽  
pp. 204-212 ◽  
Author(s):  
Ann B Gould ◽  
James W Hendrix
Keyword(s):  
Mycorrhizal Fungi ◽  
Total Population ◽  
Fungal Spores ◽  
Arbuscular Mycorrhizal ◽  
Fungal Communities ◽  
Community Relations ◽  
Species Dominance ◽  
Mine Sites ◽  
Relationship Of ◽  
Western Kentucky

Over a period of 2.5 years, mycorrhizal fungal communities in soils of five abandoned surface coal mine sites in western Kentucky were studied in relation to time following reclamation. These sites were reclaimed at different times and were in varying stages of revegetation. At the seeding stage of reclamation, low populations of mycorrhizal fungal spores of only a few species, notably Glomus microcarpum Tul. & Tul., Glomus aggregatum Schenck & Smith emend. Koske, and Glomus fasciculatum (Thaxter) Gerdemann & Trappe emend. Walker & Koske, were present. Populations of spores of these species increased rapidly during the first 1 or 2 years after reclamation. Other species, notably those with larger spores, appeared with time. Spores of one group of species were a high proportion of the total early after reclamation, then declined in relation to populations of other species. A second group appeared soon after reclamation and maintained a relatively constant proportion of the total population. A third group was inconspicuous for a few years after reclamation but increased in proportion to the total population of spores with time. Species richness was low soon after reclamation, rose slowly and erratically over 5 years, then stabilized at about 10 species. Species dominance, diversity, and evenness were relatively constant after the first 2 years of reclamation.Key words: Glomales mycorrhizal fungi, arbuscular mycorrhizal fungi, abandoned minespoil, succession, community relations.

The role of mycorrhizas in the regeneration of some Malaysian forest trees

1992 ◽  
Vol 335 (1275) ◽  
pp. 379-388 ◽  
Keyword(s):  
Ectomycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Selective Logging ◽  
Spore Density ◽  
Most Probable Number ◽  
Mycorrhizal Infection ◽  
P Fertilization ◽  
Test Species ◽  
Probable Number ◽  
Intsia Palembanica

An investigation was made into the availability of mycorrhizal inoculum and the response of tree seedlings to mycorrhizal infection in West Malaysian forests. Spores of vesicular arbuscular (VA) mycorrhizal fungi in the soil were reduced by 25% after selective logging and by 75% after heavy logging, VA infection in the roots of plants persisting on, or colonizing, a heavily logged site was reduced by up to 75% . The most probable number (MPN) of VA propagules in sieved soil was up to ten times greater than spore density, but was also greatly reduced by heavy logging. This resulted in reduced infectivity of soil from the heavily logged site, as demonstrated by reduced VA infection of bioassay plants. The infectivity of soil declined following sun drying, but sun-dried soil devoid of vegetation retained some infectivity even after 12 months storage. Overall the data suggest that root and hyphal fragments are more important than spores as inoculum in disturbed forest, and that in undisturbed forest living roots and hyphae are likely to be important sources of infection. In a pot experiment, shoot growth of two test species, Albizia falcataria (L.) Becker and Parkia speciosa Hassk. responded more to VA mycorrhizal infection than to P fertilization over the range 0-6 g triple superphosphate per 8 kg of soil. The response to inoculation with a cocktail of ‘introduced’ VA fungi propagated in pot cultures was greater than the response to inoculation with ‘indigenous’ fungi propagated in pot cultures from roots and soil collected in undisturbed forests. Another test species, Intsia palembanica Miq., also responded better to mycorrhizal infection than to P fertilization, and better to VA mycorrhizal infection than to ectomycorrhizal infection. Intsia palembanica seedlings growing around mature dipterocarps quickly became ectomycorrhizal, suggesting that at least some ectomycorrhizal fungi infect both dipterocarps and Intsia. Shorea leprosula Miq. seedlings growing naturally in the forest had ectomycorrhizas 20 days after germination, i.e. before they had true leaves, and within 7 months supported up to 11 different ectomycorrhizal fungi. However, seedlings isolated from contact with the roots of mature Shorea trees remained uninfected in the held for up to 6 months. This shows the importance of contact with living ectomycorrhizal roots for early infection of dipterocarp seedlings, a point which should be recognized in logging operations and forest regeneration programmes.

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