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.

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.

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.

The influence of vesicular–arbuscular mycorrhizae on biomass production in willow

1986 ◽  
Vol 16 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Georg F. Backhaus ◽  
Per Häggblom ◽  
Lars Owe Nilsson
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizae ◽  
Arbuscular Mycorrhizal ◽  
Dry Mass ◽  
Commercial Fertilizer ◽  
Available Nutrients ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Vesicular Arbuscular ◽  
Fertilizer Solution

Cuttings of Salixdasyclados and Salixdaphnoides were grown in clay, peat, or sand under greenhouse conditions and inoculated with endomycorrhizal roots. Uninoculated cuttings in the same substrates served as controls. All plants were fertilized with a commercial fertilizer solution. Shoot dry mass and colonization by vesicular–arbuscular mycorrhizal fungi were measured during the experiment. At the end of the experiment growth of inoculated plants was significantly enhanced in peat (p < 0.001) and sand (p < 0.01), while in clay, no effect of inoculation on growth was found. In peat and sand increased growth of plants could be correlated with frequency of vesicular–arbuscular mycorrhizal colonization. No significant differences in concentrations of P or N in leaves and stems were noted between mycorrhizal and nonmycorrhizal plants at the end of the experiment. It is concluded that vesicular–arbuscular mycorrhizae stimulate growth of willow under greenhouse conditions despite application of easily available nutrients.

Susceptibility of barley cultivars to vesicular-arbuscular mycorrhizal fungi

1995 ◽  
Vol 75 (1) ◽  
pp. 269-275 ◽  
Author(s):  
S. M. Boyetchko ◽  
J. P. Tewari
Keyword(s):  
Mycorrhizal Fungi ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Growth And Yield ◽  
Vam Fungi ◽  
University Of Alberta ◽  
Barley Cultivars ◽  
Vesicular Arbuscular ◽  
Glomus Species ◽  
The University

The relative susceptibility of selected barley cultivars produced in western Canada to vesicular-arbuscular mycorrhizal (VAM) fungi under field and greenhouse conditions was evaluated in this study. Cultivars tested under field conditions at the University of Alberta and Lacombe research stations showed no significant differences in VAM colonization of barley roots; colonization was light. Greenhouse trials at the University of Alberta with eight cultivars inoculated with individual mycorrhizal species illustrated significant differences among the barley cultivars in their reactions to Glomus dimorphicum, G. intraradices, and G. mosseae. Distinct differences were observed in the ability of each Glomus species to colonize the barley cultivars. The VAM fungi increased growth and yield in some cultivars, depending on the Glomus species. This study indicates that a degree of host-specificity exists in VAM fungi and that the host-mycorrhizal fungus genotypes may influence the effectiveness of the symbiosis. Key words: Barley, cultivars, susceptibility, VA mycorrhizal fungi

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.

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.

Method and time of alfalfa termination affects cereal growth and weed populations

2003 ◽  
Vol 83 (4) ◽  
pp. 969-976 ◽  
Author(s):  
J. R. Moyer ◽  
M. J. Clapperton ◽  
A. L. Boswall
Keyword(s):  
Soil Moisture ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Conventional Tillage ◽  
Amaranthus Retroflexus ◽  
No Tillage ◽  
Hordeum Vulgare L ◽  
Vam Fungi ◽  
N Content ◽  
Vesicular Arbuscular

Experiments were established on irrigated land at Lethbridge, Alberta, to determine the effect of timing and method of alfalfa (Medicago sativa L.) termination on weed abundance, soil moisture and N content, cereal yield and colonization of roots by vesicular arbuscular mycorrhizal (VAM) fungi. Alfalfa growth was terminated using no, minimum, and conventional tillage in either late summer, early fall, or spring. Herbicide was applied or tillage was used to control volunteer alfalfa, dandelion (Taraxacum officinale Weber), stinkweed (Thlaspi arvense L.), and kochia [Kochia scoparia (L.) Schrader] before seeding cereals. Dandelion and volunteer alfalfa density tended to be greatest after no-tillage treatments, and poor in-crop alfalfa control likely reduced cereal yields in no-tillage plots. In contrast, the major in-crop broadleaf weed, redroot pigweed (Amaranthus retroflexus L.), was most dense (7 plants m-2) in tilled plots. Both wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) yields were reduced 9 to 12% after alfalfa termination with no-tillage treatments compared with minimum or conventional tillage. In spring, after seeding, available soil N content averaged 138, 101 and 79 kg ha-1 for conventional-, minimum-and no-tillage plots, respectively; however, fall no-tillage treatments seemed to supply sufficient N for wheat and barley. Soil moisture content tended to be similar after all termination treatments. Wheat and barley responded differently to time and method of termination in terms of seedling root length and colonization by VAM fungi. The percentage of root colonized by VAM fungi was greater on both barley and wheat in no-tillage compared to cultivated treatments. It may be possible to have similar wheat and barley yields after no tillage and tilled alfalfa termination if no-tillage termination is initiated in fall and effective incrop herbicides are used for volunteer alfalfa and dandelion control. Key words: Alfalfa termination, no-tillage, N, vesicular arbuscular mycorrhizal fungi, weed density

COLONIZATION OF PEACH ROOTSTOCKS BY INDIGENOUS VESICULAR-ARBUSCULAR MYCORRHIZAL (VAM) FUNGI

1988 ◽  
Vol 68 (3) ◽  
pp. 893-898 ◽  
Author(s):  
J. A. TRAQUAIR ◽  
S. M. BERCH
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Sandy Soil ◽  
Mycorrhizal Fungi ◽  
Prunus Persica ◽  
Arbuscular Mycorrhizal ◽  
Mature Trees ◽  
Vam Fungi ◽  
Vesicular Arbuscular ◽  
Peach Rootstocks ◽  
Scion Cultivar

Six-month-old seedling rootstocks of peach cultivars Siberian C, Bailey and Harrow Blood, and mature trees in a 4-yr-old orchard which was planted with rootstock cultivars Siberian C, Bailey, Harrow Blood, Chui Lum Tao, Tzim Pee Tao, Lovell, Halford, H7338013, H7338016 and H7338019 grafted with scion cultivar Redhaven, were rated for colonization by indigenous vesicular-arbuscular mycorrhizal fungi after growth in a local sandy soil. Feeder roots of all the rootstocks were heavily colonized. However, no significant differences between the cultivars were observed with respect to percentage of root lengths colonized under these field conditions. Fungi identified on the basis of spore extraction from soil around colonized roots included G. aggregatum, G. mosseae, G. tortuosum, Scutellospora aurigloba, and S. calospora.Key words: Intraspecific receptivity, endomycorrhizae, Prunus persica

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.

The influence of fixation procedure on the ultrastructure of the host–endophyte interface of vesicular-arbuscular mycorrhizae

1977 ◽  
Vol 55 (1) ◽  
pp. 48-51 ◽  
Author(s):  
D. E. Carling ◽  
J. A. White ◽  
M. F. Brown
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Granular Material ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizae ◽  
Arbuscular Mycorrhizal ◽  
Interfacial Zone ◽  
Fixation Procedure ◽  
Vesicular Arbuscular Mycorrhizal Fungi ◽  
Host Cytoplasm ◽  
Vesicular Arbuscular

The ultrastructure of the interfacial zone which separates the intracellular structures of vesicular-arbuscular mycorrhizal fungi from host cytoplasm has been described in a variety of ways by recent investigators. Evidence is presented here which suggests that previous interpretations of the ultrastructure of the interfacial zone have been based on an artifact of fixation. Using an improved procedure, a dense, granular material was found in the interfacial zone. This material was preserved by simultaneous glutaraldehyde-osmium fixation but not by conventional prefixation and postfixation in glutaraldehyde and osmium, respectively.

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