Uptake of Atrazine by Hyphae ofGlomusVesicular-Arbuscular Mycorrhizae and Root Systems of Corn (Zea maysL.)

Weed Science ◽  
1992 ◽  
Vol 40 (1) ◽  
pp. 161-170 ◽  
Author(s):  
Sherman D. Nelson ◽  
Shahamat U. Khan
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Glomus Intraradices ◽  
Cost Benefit ◽  
Root Systems ◽  
Soil System ◽  
Treated Soil ◽  
Vesicular Arbuscular ◽  
Uptake Studies ◽  
Highly Correlated ◽  
Treatment Vessel

A system, including a specialized treatment vessel for pesticide uptake studies, was developed and experiments were carried out to determine the ability ofGlomus intraradices(Schenck & Smith),G. vesiculiferium(Thaxter), and indigenous vesicular-arbuscular mycorrhizae (VAM) fungi to influence14C-atrazine uptake and transfer to corn. Uptake by root systems with and without VAM infection was compared to uptake by VAM hyphal systems by controlling access to14C-atrazine-treated soil. Hyphal systems ofGlomusspecies were able to remove14C-residue from soil and transfer these to corn. Amount of14C-residue transferred to corn through hyphal systems was highly correlated to the level of VAM root infection which varied among VAM species. In root systems, variations in14C-residue uptake resulting from mycorrhization were largely explained in terms of the negative correlation between level of infection and root mass located in14C-atrazine-treated soil. Allocation of14C-residue to shoot tissues of corn was greater when14C-residues were taken up through root systems rather than through hyphal systems. There were significant effects of VAM species on14C-residue compartmentalization between methanol extractable and nonextractable portions of corn tissues. Data from these experiments in a confined soil system were related to VAM cost-benefit relationships and indicate a significant role for VAM in determining atrazine fate in agricultural systems.

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

1986 ◽  
Vol 64 (8) ◽  
pp. 1739-1744 ◽  
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.

Vesicular–arbuscular mycorrhizal colonization in Zea mays affected by breeding for resistance to fungal pathogens

1990 ◽  
Vol 68 (5) ◽  
pp. 1039-1044 ◽  
Author(s):  
Ronald Toth ◽  
Deborah Toth ◽  
David Starke ◽  
David R. Smith
Keyword(s):  
Zea Mays ◽  
Mycorrhizal Fungi ◽  
Fungal Pathogens ◽  
Arbuscular Mycorrhizae ◽  
Zea Mays L ◽  
Arbuscular Mycorrhizal ◽  
Root Systems ◽  
Mycorrhizal Colonization ◽  
Breeding Programs ◽  
Vesicular Arbuscular

Inbred lines of Zea mays L. (maize) selected for a range of resistances to a variety of fungal pathogens were assayed for percentage colonization by vesicular–arbuscular mycorrhizal fungi. Inbreds that were generally resistant to a number of fungal pathogens had significantly lower levels of vesicular–arbuscular mycorrhizae, matured more slowly, and had larger root systems. Disease-susceptible inbreds had significantly higher levels of mycorrhizal colonization, matured more rapidly, and had smaller root systems. It is uncertain if a general resistance to fungal pathogens or rate of root development, separately or in combination, may have influenced mycorrhizal colonization levels. Irrespective of cause, present breeding programs for disease resistance in maize do influence the plants ability to form mycorrhizae.

Endomycorrhizal Role for Interspecific Transfer of Phosphorus in a Community of Annual Plants

Science ◽  
1982 ◽  
Vol 217 (4563) ◽  
pp. 941-943 ◽  
Author(s):  
NONA CHIARIELLO ◽  
JAMES C. HICKMAN ◽  
HAROLD A. MOONEY
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Root Systems ◽  
Nutrient Transfer ◽  
Annual Plants ◽  
Simple Diffusion ◽  
Taxonomic Affinity ◽  
Neighbor Effects ◽  
Vesicular Arbuscular ◽  
Annual Grassland ◽  
Interspecific Transfer

Phosphorus-32 applied to leaves of Plantago erecta in a serpentine annual grassland reached the shoots of about 20 percent of the close neighbors. Vesicular-arbuscular mycorrhizae connect the root systems of neighbors of different species and probably mediate nutrient transfers among them. Spatial patterns of transfer show that taxonomic affinity, distance from donor, and size of recipient do not serve as predictors of transfer and that models of transfer by simple diffusion are not appropriate. No alternative predictor was discovered. The results underscore the importance of belowground interactions in explaining neighbor effects, but the factors controlling nutrient transfer and its consequences for community structure appear complex.

scholarly journals Use of Vesicular–Arbuscular Mycorrhizae in Boston Fern Production: II. Evaluation of Four Inocula

HortScience ◽  
1990 ◽  
Vol 25 (4) ◽  
pp. 416-419 ◽  
Author(s):  
F. Ponton ◽  
Y. Piché ◽  
S. Parent ◽  
M. Caron
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Glomus Intraradices ◽  
Arbuscular Mycorrhizal ◽  
The Other ◽  
P Fertilization ◽  
Vesicular Arbuscular Mycorrhizae ◽  
Vesicular Arbuscular ◽  
Mycorrhizal Inoculation ◽  
Better Than

Rooted plantlets of in vitro micropropagated Boston fern [Nephrolepis exaltata (L.) Schott var. Whitmanii] were transferred to pots containing a brown peat-based mix and simultaneously inoculated with one of four species of Glomus. Glomus intraradices and G. clarum formed rapid and extensive infection in Nephrolepis exaltata roots, while Glomus vesiculiferum and G. versiforme showed a significantly slower rate of infection. The high P fertilized control performed better than the other treatments, except in the number of fronds, which was similar. From the four mycorrhizal treatments, plants inoculated with Glomus vesiculiferum showed the most significant increase in growth when compared with the low P fertilization control. These results led us to re-examine vesicular-arbuscular mycorrhizal inoculation as an alternative to higher P fertilization in horticultural Boston fern production.

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.

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