Occurrence and isolation of vesicular–arbuscular mycorrhizae in cropped field soils of Saskatchewan, Canada

1993 ◽  
Vol 39 (6) ◽  
pp. 567-575 ◽  
Author(s):  
Narayan C. Talukdar ◽  
James J. Germida
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Arbuscular Mycorrhizal ◽  
Triticum Aestivum L ◽  
Wheat Roots ◽  
Wheat Field ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Vesicular Arbuscular ◽  
Field Soils ◽  
Vam Colonization ◽  
Study Sites

Soil and root samples collected from fields cropped to spring wheat (Triticum aestivum L. cv. Katepwa) and lentil (Lens esculenta L. cv. Eston) at 11 sites across four soil zones of Saskatchewan were analyzed for spore numbers, level of vesicular–arbuscular mycorrhizal (VAM) colonization, and VAM species. The number of VAM spores detected in field soils ranged from 78 to 272 per 100 g soil. Vesicular–arbuscular mycorrhizae colonized wheat and lentil at all the field study sites, but levels of colonization in the two crops varied from site to site and the differences were more pronounced in wheat than in lentil. Generally, lentil both exhibited a higher percentage of VAM colonized roots and contained more arbuscules and vesicles than wheat roots. However, wheat appeared to be colonized by different types of VAM depending on the field sites. Differences in VAM colonization were not related to the moisture and temperature gradient of the four soil zones or soil properties. Seven VAM species were isolated by enriching indigenous VAM mixtures (collected from wheat field soils of six field sites) on maize. The VAM isolated most closely resembled Acaulospora denticulata, Gigaspora decipiens, Glomus clarum, Glomus etunicatum, Glomus fasciculatum, Glomus mosseae, and Glomus versiforme. The species composition of the VAM community varied at the different field sites.Key words: VAM, Acaulospora, Gigaspora, Glomus.

Vesicular – arbuscular mycorrhizae in disturbed and revegetated sites from La Gran Sabana, Venezuela

1992 ◽  
Vol 70 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Gisela Cuenca ◽  
Milagros Lovera
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Plant Cover ◽  
Ground Cover ◽  
Arbuscular Mycorrhizal ◽  
Most Probable Number ◽  
Probable Number ◽  
Organic Layers ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Disturbed Areas ◽  
Vesicular Arbuscular

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.

Local reduction of mycorrhizal arbuscule frequency in enriched soil microsites

1994 ◽  
Vol 72 (7) ◽  
pp. 998-1001 ◽  
Author(s):  
S. E. Duke ◽  
R. B. Jackson ◽  
M. M. Caldwell
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Plant Root ◽  
Arbuscular Mycorrhizal ◽  
Soil Heterogeneity ◽  
Water Control ◽  
Local Reduction ◽  
Vesicular Arbuscular ◽  
Vam Colonization ◽  
Development Regulation ◽  
Control Patch

Increased nutrient availability reduces vesicular–arbuscular mycorrhizal (VAM) associations with plants, but whether increased nutrients in small volumes of soil affect local VAM colonization is not known. In a field experiment we investigated VAM colonization at different times following fertilization of small soil patches. Soil volumes of ~ 1000 cm3 were treated with a nutrient solution (enriched patch) or distilled water (control patch) on opposite sides of individual plants of the tussock grass Agropyron desertorum and the shrub Artemisia tridentata. Agropyron had significantly lower (p = 0.03) arbuscular infection in the locally enriched patches compared to control patches (32 and 40%, respectively). This reduced arbuscule frequency was apparent at the first sampling (3 days following treatment application) and remained lower in each subsequent sampling (as much as 30% lower than the control patches). Artemisia revealed a similar pattern in arbuscule frequency but was not statistically significant. Our results suggest that a plant can locally reduce VAM development, since arbuscule frequency specifically was locally reduced even though vesicle and overall infection was not. Since mycorrhizal infection does not increase, we conclude that increased plant root proliferation and uptake capacity are likely to be more important for the exploitation of temporary nutrient pulses or patches than is increased mycorrhizal activity. Key words: arbuscule, nutrient exploitation, phosphorus, reduced development, regulation of colonization, soil heterogeneity, vesicular–arbuscular mycorrhizae.

Development of vesicular–arbuscular mycorrhizae in a young sweetgum plantation

1985 ◽  
Vol 15 (6) ◽  
pp. 1061-1064 ◽  
Author(s):  
Paul P. Kormanik
Keyword(s):  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizae ◽  
Fungal Spores ◽  
Arbuscular Mycorrhizal ◽  
Available Phosphorus ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Vesicular Arbuscular ◽  
Mycorrhizal Development ◽  
Crown Closure ◽  
Arbuscular Mycorrhizal Fungal

Sweetgum seedlings with vesicular–arbuscular mycorrhizae formed by Glomusetunicatum or Glomusdeserticola in nursery soil with 30 ppm available phosphorus (P) and nonmycorrhizal seedlings grown in nursery soil with 800 ppm available P were outplanted and whole trees were excavated periodically over the next 5 years in the plantation to follow mycorrhizal development. Four months after outplanting, roots of all initially nonmycorrhizal seedlings had formed vesicular–arbuscular mycorrhizae and the degree of root colonization was comparable to that of initially vesicular–arbuscular mycorrhizal seedlings. New feeder roots did not develop on seedlings of any treatment until almost 5 months after planting. By the end of the first growing season and for the remainder of the study, vesicular–arbuscular mycorrhizae development was approximately the same on all seedlings. The proportion of feeder roots colonized by vesicular–arbuscular mycorrhizal fungi stabilized at 65 to 70%; approximately 56% of the cortical tissues of all feeder roots were colonized with arbuscles, vesicles, and hyphae. Periodic assays of the soil in the plantation showed that vesicular–arbuscular mycorrhizal fungal spores gradually declined from an initial high of 3600 spores to 620 spores per 100-cm3 soil sample after 5 years. This decline was probably caused by crown closure of the sweetgum trees which gradually suppressed understory vegetation.

The morphology of vesicular – arbuscular mycorrhizae in Clintonia borealis and Medeola virginiana

1996 ◽  
Vol 74 (5) ◽  
pp. 679-685 ◽  
Author(s):  
Paul Widden
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Deciduous Forest ◽  
Arbuscular Mycorrhizal ◽  
Cortical Layer ◽  
Cortical Cells ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Forest Herbs ◽  
Vesicular Arbuscular ◽  
Innermost Layer ◽  
Inner Cortex

During a survey of the vesicular–arbuscular mycorrhizal (VAM) associations of forest herbs in a deciduous forest in the southern Laurentian mountains in Quebec, two liliaceous species, Clintonia borealis and Medeola virginiana, revealed very distinctive morphology. In both species, once the epidermis was penetrated, the fungus spread towards the centre of the root via intracellular hyphae until the innermost layer of the cortex was reached, at which point the fungus spread laterally and tangentially through the cortical cells adjacent to the endodermis via a series of banana-shaped projections (bobbits). These eventually differentiated into the arbuscules and the VAM might spread from this inner cortical layer back into the outer cortical layers. In C. borealis, the hyphae coiled in the cortex, and vesicles were formed in the upper cortical cells. In M. virginiana, no coiling took place, but extensive diverticulae were produced by the intracellular hyphae in the cortical cells, close to their point of exit, and vesicles were produced in the inner cortex as swellings from the bobbits. These two mycorrhizae have some similarities to one in Colchicum autumnale described by I. Gallaud (1905. Rev. Gen. Bot. 17). Keywords: vesicular–arbuscular mycorrhizae, Clintonia borealis, Medeola virginiana, Liliaceae, morphology.

scholarly journals Vesicular–Arbuscular Mycorrhizae Colonization of Redwood and Incense Cedar Seedlings following Storage

HortScience ◽  
1994 ◽  
Vol 29 (11) ◽  
pp. 1362-1365 ◽  
Author(s):  
U. Afek ◽  
L.A. Lippet ◽  
D. Adams ◽  
J.A. Menge ◽  
E. Pond
Keyword(s):  
Glomus Mosseae ◽  
Arbuscular Mycorrhizae ◽  
Arbuscular Mycorrhizal ◽  
Sequoia Sempervirens ◽  
Fresh Weight ◽  
Coast Redwood ◽  
Moisture Contents ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Vesicular Arbuscular

Vesicular–arbuscular mycorrhizal inoculum consisting of a mixture of roots of coast redwood [Sequoia sempervirens (D. Don)], soil, and spores of Glomus mosseae (Nicol. and Gerd.) Gerdemann and Trappe was tested for viability and efficacy following storage for 4 or 8 weeks at 4, 9, 15, or 24C and moisture contents of 0%, 6%, 12%, or 17%. Storage regimes did not have any effect on the number of spores of Glomus mosseae recovered after storage. However, germinability of the spores decreased from 35% before storage to 10% to 31% during storage, especially under typical ambient room conditions (17% moisture at 24C). Maximum colonization of coast redwood, sierra redwood [Sequoiadendrom giganteum (Lindl.) Buchh.], and incense cedar (Libocedrous decurrens Torr.) was achieved after inoculation with 1 inoculum: 1 potting mix dilution (w/w). However, plant fresh weight was highest following inoculation with a 1 inoculum: 5 potting mix dilution (w/w). Dried inoculum was effective when stored at 24C, or below 10C when moist.

scholarly journals The Effect of Four Composts on the Establishment of Vesicular–Arbuscular Mycorrhizae in Soilless Media

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 539D-539
Author(s):  
Michelle Miller ◽  
Robert Linderman ◽  
Leslie Fuchigami
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Growth Parameters ◽  
Fungal Spore ◽  
Exchange Capacity ◽  
Mycorrhizal Colonization ◽  
Mushroom Compost ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Vesicular Arbuscular ◽  
Vam Colonization ◽  
Mineral Soils

The beneficial use of vesicular–arbuscular mycorrhizae (VAM) in mineral soils is well-documented, but little is known about the effect of soilless mixes on mycorrhizal colonization of roots. Previous research indicates that mycorrhizal colonization is affected by pH, soluble salts, phosphorus levels, cation exchange capacity, percent organic matter, and some peats. No other research has been published, to our knowledge, on the role of commonly used horticultural composts and mycorrhizal establishment. This study examined four different composts for their effect on VAM establishment using onion roots as an indicator. The composts used in the study were vermicompost, spent mushroom compost, yard waste compost, and processed manure fiber. Plant growth parameters, phosphorus (P) levels and rate of desorption, and microbial populations were analyzed in relation to the percent of VAM colonization of the roots. Significant differences were found in percent VAM colonization between composts. The primary factors influencing VAM colonization were the initial levels of P in the blends and the rate and amount of P released. The experiment raised questions about the balance between mineralized P and organic P in composts and their effect on VAM fungal spore germination.

Survey of vesicular–arbuscular mycorrhizae in lettuce production in relation to management and soil factors

1998 ◽  
Vol 130 (2) ◽  
pp. 173-182 ◽  
Author(s):  
R. L. MILLER ◽  
L. E. JACKSON
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Management Practices ◽  
Root Colonization ◽  
Soil Conditions ◽  
Multivariate Statistical ◽  
Spore Number ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Wide Range ◽  
Vesicular Arbuscular ◽  
Vam Colonization

The occurrence of vesicular–arbuscular mycorrhizae (VAM) root colonization and spore number in soil was assessed for 18 fields under intensive lettuce (Lactuca sativa L.) production in California during July and August of 1995. Data on management practices and soil characteristics were compiled for each field, and included a wide range of conditions. The relationship between these factors and the occurrence of VAM in these fields was explored with multivariate statistical analysis. VAM colonization of lettuce tended to decrease with the use of chemical inputs, such as pesticides and high amounts of P and N fertilizers. Addition of soil organic matter amendments, the occurrence of other host crops in the rotation, and soil carbon[ratio ]phosphorus and carbon[ratio ]nitrogen ratios, were positively associated with VAM colonization of lettuce roots. The number of VAM spores in soil was strongly correlated with the number of other host crops in the rotation, the occurrence of weed hosts and sampling date, but was more affected by general soil conditions than by management inputs. Higher total soil N, C and P, as well as CEC, were inversely related to soil spore number. A glasshouse study of the two primary lettuce types sampled in the field showed no significant differences in the extent of root colonization under similar growing conditions. The results of this study are compared with other studies on the effects of management and soil conditions on mycorrhizal occurrence in agriculture.

scholarly journals The Use of Vesicular-Arbuscular Mycorrhizae in Boston Fern Production: I. Effects of Peat-based Mixes

HortScience ◽  
1990 ◽  
Vol 25 (2) ◽  
pp. 183-189 ◽  
Author(s):  
F. Ponton ◽  
Y. Piché ◽  
S. Parent ◽  
M. Caron
Keyword(s):  
Root Growth ◽  
Arbuscular Mycorrhizae ◽  
Arbuscular Mycorrhizal ◽  
Growth Increment ◽  
Fungal Activity ◽  
N Concentration ◽  
Vesicular Arbuscular ◽  
Vam Colonization ◽  
Uninoculated Control

The horticultural Boston fern [Nephrolepis exaltata (L.) Schott cv. Verona] was micropropagated in vitro using commercial techniques. Rooted plantlets were transferred into pots containing one of three test substrates made of peat and vermiculite and subsequently inoculated with one of two species of Glomus. Survival of uninoculated control plants growing on a black peat-based mix was less than that on a brown peat-based mix. Vesicular-arbuscular mycorrhizal (VAM) inoculation significantly increased survival on the former, but not the latter, substrate. The growth of roots was enhanced in brown peatmoss, but VAM colonization was faster with black peatmoss. Compared to uninoculated controls growing under the same fertilization regime, inoculated plants had significantly higher frond P and N concentration and also showed better frond and root growth. On a growth-increment basis, our results suggested that the brown peat-based mixed was more suitable for fungal activity and fern growth.

A technique for the isolation of intramatrical vesicles from vesicular–arbuscular mycorrhizae

1984 ◽  
Vol 62 (7) ◽  
pp. 1466-1468 ◽  
Author(s):  
S. Jabaji-Hare ◽  
S. I. Sridhara ◽  
B. Kendrick
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Arbuscular Mycorrhizal ◽  
Allium Porrum ◽  
Vam Fungi ◽  
Potential Yield ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Vesicular Arbuscular

A method for isolating the vesicles of vesicular–arbuscular mycorrhizal (VAM) fungi from within the roots of Allium porrum is presented. Colonized roots were homogenized with 0.3 M sucrose – 0.05 M NaHCO3 and filtered through cheesecloth. The supernatant was centrifuged (180 min, 82 000 g) on 1.3 M sucrose – 15 mM CsCl. Our tests yielded 46 000 vesicles per operator day, but the potential yield is limited only by the amount of root material available.

Utilization of vesicular–arbuscular mycorrhizal fungi in agriculture

1983 ◽  
Vol 61 (3) ◽  
pp. 1015-1024 ◽  
Author(s):  
J. A. Menge
Keyword(s):  
Mycorrhizal Fungi ◽  
Large Scale ◽  
Arbuscular Mycorrhizae ◽  
Crop Yields ◽  
Natural Populations ◽  
Arbuscular Mycorrhizal ◽  
Vam Fungi ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Vesicular Arbuscular ◽  
Direct Inoculation

Commercial use of vesicular–arbuscular mycorrhizae (VAM) may be an alternative to rising agricultural energy and fertilizer costs. Vesicular–arbuscular mycorrhizae may be able to increase crop yields while reducing fertilizer and energy inputs. Since mycorrhizal fungi are naturally present in most soils, their unique fertilizer abilities are already being utilized by most crop plants. Commercial uses of VA mycorrhizal fungi are therefore currently restricted to situations where the natural populations of VAM fungi have been destroyed or damaged such as in fumigated or chemically treated areas, greenhouses, and disturbed areas such as coal spoils, strip mines, waste areas, or road beds. Commercial production of VAM inoculum is presently being attempted at several locations in the U.S. Vesicular–arbuscular mycorrhizal inoculum is produced by growing VAM fungi on the roots of suitable host plants under aseptic greenhouse conditions The inoculum consists of the host-plant growth medium and host roots associated with VAM hyphae and spores which have been ground and dried. Most large-scale uses of VAM involve the establishment of the mycorrhizae on seedlings which will be transplanted to the field. Large-scale methods for direct inoculation with VAM have not yet been devised, but in small trials, layering, banding, broadcasting, and pelleting seed with VAM inoculum have proved effective. Methods for determining what soils are most likely to benefit from applications of VAM fungi are available. The potential for employing VAM fungi on a wide scale in agriculture is dependent on the development of crop growth-promoting strains of VAM which are superior to native soil populations of VAM fungi.

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