The physiology of vesicular–arbuscular endomycorrhizal symbiosis

1983 ◽  
Vol 61 (3) ◽  
pp. 944-963 ◽  
Author(s):  
D. S. Hayman
Keyword(s):  
Mycorrhizal Fungi ◽  
Biological Diversity ◽  
Copper Ions ◽  
Root Surface ◽  
P Uptake ◽  
Mycorrhizal Symbiosis ◽  
Va Mycorrhizae ◽  
Wide Range ◽  
Vesicular Arbuscular ◽  
Va Mycorrhizal Fungi

The enhanced growth of plants infected by vesicular–arbuscular (VA) mycorrhizal fungi results primarily from improved uptake of soil phosphate. Extra phosphate reaches the root through the fungal hyphae, which tap the soluble P in soil beyond the phosphate-depletion zone near the root surface. This mechanism can explain the many corrrelations between root geometry and mycotrophy and other nutritional effects of VA mycorrhizae such as increased uptake of zinc and copper ions. Recently VA mycorrhizae have been shown to increase the levels of chlorophyll and some hormones in plants and to alleviate water stress. Legumes are now receiving considerable attention because VA mycorrhiza affects nitrogen fixation in them indirectly by its action on P uptake. In this review the physiology of the VA mycorrhizal symbiosis is discussed in categories reflecting successive stages in its formation and function: (i) activation of the VA mycorrhizal propagules; (ii) penetration and initial infection of the host plant; (iii) spread of infection in roots; (iv) response of the plant; the components and mechanisms of VA mycorrhizal systems; (v) benefits to the fungus; carbon sinks; and (vi) imbalances in the symbiosis. It is suggested that studies on the physiological complexities of VA mycorrhizal associations should take more account of the biological diversity of VA mycorrhizal fungi and the wide range of host–endophyte–soil specificities.

Vesicular–arbuscular endomycorrhizal associations of some desert plants of Baja California

1981 ◽  
Vol 59 (6) ◽  
pp. 1056-1060 ◽  
Author(s):  
Sharon L. Rose
Keyword(s):  
Mycorrhizal Fungi ◽  
Sonoran Desert ◽  
Baja California ◽  
Fungal Spores ◽  
Desert Plants ◽  
Endemic Plants ◽  
Mycorrhizal Associations ◽  
Glomus Spp ◽  
Vesicular Arbuscular ◽  
Va Mycorrhizal Fungi

Endemic plants of the Sonoran Desert of Baja California were sampled for mycorrhizal associations. Eight of the 10 plant species examined were colonized by vesicular–arbuscular (VA) mycorrhizal fungi. Soil sievings revealed chlamydospores of three VA mycorrhizal Glomus spp.; G. microcarpus, G. fasciculatus, and G. macrocarpus. At the time of sampling, the populations of VA fungal spores in the soil were low, with one to five chlamydospores per 100 g soil sample.

The effect of soil pH on the formation of VA mycorrhizas by two species of Glomus

Soil Research ◽  
1985 ◽  
Vol 23 (2) ◽  
pp. 253 ◽  
Author(s):  
LK Abbott ◽  
AD Robson
Keyword(s):  
Soil Ph ◽  
Mycorrhizal Fungi ◽  
Subterranean Clover ◽  
Vesicular Arbuscular ◽  
Va Mycorrhizal Fungi ◽  
Four Levels ◽  
Ph Level ◽  
Ph Range ◽  
Spread Of Infection ◽  
Glomus Sp

Two species of vesicular-arbuscular (VA) mycorrhizal fungi differed in their ability to infect subterranean clover roots when soil pH was changed by liming. In a glasshouse experiment, Glomus fasciculatum infected extensively at each of four levels of soil pH (range 5.3-7.5). Glomus sp. (WUM 16) only infected extensively at the highest pH level. Liming the soil depressed plant growth, but this effect was almost entirely overcome by inoculation with G. fasciculatum. In the second experiment, Glomus sp. (WUM 16) failed to spread from existing infection within roots of subterranean clover when soil pH was 5.3 or lower. The lack of spread of infection was associated with an inability of hyphae of this fungus to grow in the soil used unless it was limed to give a pH at least greater than 5.3.

Vesicular-Arbuscular Mycorrhiza and Phosphorus Uptake of Chickpea Grown in Northern Syria

1992 ◽  
Vol 28 (4) ◽  
pp. 433-442 ◽  
Author(s):  
Edwin Weber ◽  
Eckhard George ◽  
Douglas P. Beck ◽  
Mohan C. Saxena ◽  
Horst Marschner
Keyword(s):  
Mycorrhizal Fungi ◽  
Field Experiments ◽  
Phosphorus Uptake ◽  
Arbuscular Mycorrhizal ◽  
P Uptake ◽  
Mycorrhizal Infection ◽  
P Fertilization ◽  
Flowering Stage ◽  
P Concentration ◽  
Vesicular Arbuscular

SUMMARYInoculation with vesicular-arbuscular mycorrhizal fungi (VAMF) improved growth of chick-pea (Cicer arielinum L.) and doubled phosphorus (P) uptake at low and intermediate levels of P fertilization in a pot experiment on sterilized low-P calcareous soil. In field experiments at Tel Hadya, northern Syria, growth, shoot P concentration and seed yield of spring-sown chickpea remained unaffected by inoculation with VAMF or by P fertilization. The mycorrhizal infection of chickpea was high (approximately 75% of root length mycorrhizal at the flowering stage) irrespective of inoculation with VAMF or P fertilization and may ensure efficient P uptake under field conditions.

Tripartite associations in snowbrush (Ceanothus velutinus): effect of vesicular–arbuscular mycorrhizae on growth, nodulation, and nitrogen fixation

1981 ◽  
Vol 59 (1) ◽  
pp. 34-39 ◽  
Author(s):  
S. L. Rose ◽  
C. T. Youngberg
Keyword(s):  
Host Plant ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizae ◽  
Nitrogenase Activity ◽  
Mycorrhizal Fungus ◽  
Nodule Formation ◽  
Nitrogen Fixing ◽  
Symbiotic Associations ◽  
Vesicular Arbuscular ◽  
Va Mycorrhizal Fungi

Symbiotic associations were established between nitrogen-fixing nonleguminous (actinorrhizal) snowbrush (Ceanothus velutinus Dougl.) seedlings and two categories of microorganisms: vesicular–arbuscular (VA) mycorrhizal fungi and a filamentous actinomycete capable of inducing nodule formation. The actinomycete is housed in nodules where fixation of atmospheric dinitrogen occurs and is made available to the host plant; the mycorrhizal fungus is both inter- and intra-cellular within the root tissue and may be found within the nodules. The two major nutrients, N and P, are made available and can be supplied to the host plant by these two symbiotic microorganisms. The root system of snowbrush seedlings was dually colonized by VA mycorrhizal fungi and a nitrogen-fixing actinomycete and the possibility of a direct interaction between the endophytes in the symbioses was investigated. Dually infected plants showed increases in total dry weight of shoots and roots, number of nodules, weight of nodular tissue, as well as higher levels of N, Ca2+, and P, and an increase in nitrogenase activity as measured by acetylene reduction.

Vesicular–arbuscular mycorrhiza influence growth but not mineral concentrations in seedlings of eight sweetgum families

1979 ◽  
Vol 9 (2) ◽  
pp. 218-223 ◽  
Author(s):  
R. C. Schultz ◽  
P. P. Kormanik ◽  
W. C. Bryan ◽  
G. H. Brister
Keyword(s):  
Arbuscular Mycorrhiza ◽  
Nutrient Uptake ◽  
Mycorrhizal Fungi ◽  
Growing Season ◽  
Initial Growth ◽  
Soil Mixture ◽  
Vesicular Arbuscular ◽  
Va Mycorrhizal Fungi ◽  
Mineral Concentrations

Seedlings of eight half-sib sweetgum (Liquidambarstyraciflua L.) families were grown for 6 months in a fumigated soil mixture, with or without inoculum from a mixture of Glomusmosseae and Glomusetunicatus fungi, at levels of 140, 280, 560, and 1120 kg/ha of 10–10–10 fertilizer. All seedlings received three additions of 187 kg/ha of N during the growing season. Inoculated seedlings had significantly greater biomass, height, and stem diameters at each fertilizer level than nonmycorrhizal control seedlings. Significant differences in growth occurred between families in mycorrhizal plants. However, fertilizer did not significantly affect growth or nutrient uptake of the seedlings. Inoculation with VA mycorrhizal fungi did not increase N, P, K, or Mg concentrations in the leaves, stems, or roots. Leaves of VA mycorrhizal seedlings had higher concentrations of calcium but stems and roots had lower concentrations of this element than the nonmycorrhizal seedlings. Seedlings with endomycorrhizae contained higher absolute quantities of each nutrient simply because of their greater biomass. The results suggest that the role of VA mycorrhizal fungi in the initial growth of sweetgum seedlings may be the result of physiological stimuli other than increased nutrient uptake.

Effects of Arbuscular Mycorrhizal Fungi on Grass and Weed in Acidic Andosol

2013 ◽  
Vol 281 ◽  
pp. 664-669
Author(s):  
En Wu ◽  
Guo Rong Xin ◽  
Kazuo Sugawara
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Volcanic Ash ◽  
Arbuscular Mycorrhizal ◽  
P Uptake ◽  
Mycorrhizal Symbiosis ◽  
Ph Gradients ◽  
Anthoxanthum Odoratum ◽  
Dactylis Glomerata L ◽  
Positive Effect

With the aggravation of volcanic ash Andosol acidification, artificial forage grass Dactylis glomerata L. gradual degradation, replaced by weed plant Anthoxanthum odoratum L., but the mechanism is unclear. In order to reveal the mechanism, this study used Andosol soil as matrix, explored the effects of arbuscular mycorrhizal fungi on D. glomerata and A. odoratum at different pH gradients in acidic Andosol by glasshouse experiment. The results show that the mycorrhizal colonization of D. glomerata strongly affected by soil pH, but the A. odoratum was not yet. The mycorrhizal symbiosis led to a positive effect on growth and P uptake of D. glomerata and A. odoratum. Consider to invasion and expansion of A. odoratum in severity acidic pasture is origin of this specificity on arbuscular mycorrhizal symbiosis in acidic soil other than D. glomerata.

Effects of native vesicular–arbuscular mycorrhizal fungi and phosphate fertilizer on red clover growth in acid soils

1988 ◽  
Vol 111 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Maria J. Sainz ◽  
J. Arines
Keyword(s):  
Mycorrhizal Fungi ◽  
Acid Soils ◽  
Red Clover ◽  
Arbuscular Mycorrhizal ◽  
Phosphate Fertilizer ◽  
P Uptake ◽  
Soil Conditions ◽  
Vesicular Arbuscular ◽  
Fungal Populations ◽  
Mycorrhizal Plants

SummaryThe effect of P applications and native vesicular-arbuscular mycorrhiza (VAM) on the growth and P nutrition of red clover plants was studied in two acid hill soils with similar edaphic characteristics.Mycorrhizal and non-mycorrhizal plants were compared under sterilized soil conditions. Plant growth increased on P addition in both soils, but the effect of mycorrhiza in improving drymatter production and P uptake was significant only in one of the soils. Fourteen and twenty-five mg/kg Olsen-P were needed in this soil to obtain the same yields by mycorrhizal and non-mycorrhizal plants, respectively. Results are explained in terms of a different effectiveness of the two fungal populations, and the possible effect of the soil sterilization process on percentage VAM infection is discussed.

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