Vesicular-arbuscular mycorrhizae (VAM) improve phosphorus and zinc nutrition and growth of pigeonpea in a Vertisol

1991 ◽  
Vol 42 (5) ◽  
pp. 835 ◽  
Author(s):  
NP Wellings ◽  
AH Wearing ◽  
JP Thompson
Keyword(s):  
Root Rot ◽  
Arbuscular Mycorrhizae ◽  
Agricultural Practices ◽  
Dry Weight ◽  
Vam Fungi ◽  
P Concentration ◽  
Zn Concentration ◽  
Vesicular Arbuscular ◽  
Vam Colonization ◽  
Mycorrhizal Plants

In a glasshouse trial, pigeonpea (Cajanus cajan) was grown in a Vertisol from the Darling Downs, Qld. The experimental design included two rates of inoculation with vesicular-arbuscular mycorrhizal (VAM) fungi (nil and inoculated), three rates of phosphorus (P) application and two of zinc (Zn), and inoculation (nil and inoculated) with a recently discovered pathogen of pigeonpea, Phytophthora drechsleri Tucker (Pdr). lnoculation with the pathogen was included in the factorial design to investigate any effect of VAM on root rot. Plants responded to inoculation with VAM fungi, showing that the growth of pigeonpea is highly dependent upon mycorrhizal colonization of its root system. The mycorrhizal plants yielded, on average, 3.3 times the dry weight of the non-mycorrhizal plants. Shoot dry weight and Zn concentration of the shoots were both exponentially related to per cent VAM colonization of the root length ( R2 values of 0.904 and 0.644 respectively) and P concentration was linearly related to VAM colonization (R2 = 0.888). VAM increased P concentration, P uptake, Zn concentration, Zn uptake and P/Zn ratio, indicating enhanced growth through improved P and to a lesser extent Zn nutrition. Zinc fertilizer (15 mg kg-1 soil) without Phytophthora inoculation was fungitoxic to the mycorrhizae, decreasing per cent VAM colonization and depressing plant growth. lnoculation with Pdr did not result in infection and root rot symptoms. However, it did overcome the Zn toxicity, possibly through organic chelation effects, and thereby enhanced VAM colonization. Greatest VAM colonization and best plant nutrition and growth were obtained with the combination of VAM inoculation, Pdr inoculation, Zn (15 mg kg-1) and P (10 mg kg-1). Our results indicate the importance of maintaining adequate levels of VAM fungi in soil through appropriate agricultural practices in order to maximize pigeonpea growth.

scholarly journals Influence of Formononetin and NaCl on Mycorrhizal Colonization and Fusarium Crown and Root Rot of Asparagus

Plant Disease ◽  
2002 ◽  
Vol 86 (12) ◽  
pp. 1318-1324 ◽  
Author(s):  
Wade H. Elmer
Keyword(s):  
Sodium Chloride ◽  
Root Rot ◽  
Arbuscular Mycorrhizae ◽  
Soil Cores ◽  
Fusarium Spp ◽  
Left Behind ◽  
Vesicular Arbuscular ◽  
Vam Colonization ◽  
Crown And Root Rot ◽  
Field Plots

Replanted asparagus fields commonly fail to produce a profitable stand due to alleopathic residues left behind from the previous asparagus crop, elevated densities of pathogenic Fusarium spp., and low densities of vesicular arbuscular mycorrhizae (VAM). Formononetin, a plant isoflavone that stimulates VAM spores to germinate, and sodium chloride (NaCl), a disease-suppressing amendment, were evaluated alone and in combination for their effect on reestablishing asparagus at two locations in abandoned asparagus fields. Greenhouse studies also were conducted with naturally and artificially infested soils. Formononetin was applied as a crown soak or soil drench, and NaCl was applied as a granular treatment. Feeder roots from soil cores sampled from field plots and from greenhouse transplants were assayed for colonization by VAM and for lesions caused by Fusarium oxysporum and F. proliferatum. Formononetin increased the number of VAM vesicles in roots from the field and greenhouse studies and reduced the percent root lesions caused by Fusarium spp. when compared with the nontreated controls. NaCl was more effective than formononetin in reducing the percentage of root lesions in both field and greenhouse experiment when compared with untreated plants but had no effect on VAM colonization. However, there was evidence that NaCl negated the effect of formononentin on VAM colonization. The NaCl treatment increased the May 2001 spear number by 15% and marketable spear weight by 23%. At one site, treatment with formononetin increased mean number of stalks per plant by 29% in 2000 and 14% in 2001. Both formononetin and NaCl improve growth and reduce disease of asparagus in replanted asparagus and may be useful in reestablishing asparagus in abandoned asparagus field.

Effects of benomyl, clipping, and competition on growth of prereproductive Lotus corniculatus

1993 ◽  
Vol 71 (9) ◽  
pp. 1169-1175 ◽  
Author(s):  
Victoria A. Borowicz
Keyword(s):  
Arbuscular Mycorrhizae ◽  
Root Nodules ◽  
Arbuscular Mycorrhizal ◽  
Lotus Corniculatus ◽  
Growth Reduction ◽  
Vam Fungi ◽  
Growth Depression ◽  
Vesicular Arbuscular ◽  
Vam Colonization ◽  
Target Plant

Vesicular–arbuscular mycorrhizae, defoliation, and competition can influence survival, growth, and fecundity of plants, but the combined effects of these factors are not well known. I examined how combinations of these factors influence biomass allocation and investment in root nodules by prereproductive Lotus corniculatus and whether the effects were ephemeral. Soil with vesicular–arbuscular mycorrhizal (VAM) fungi was treated with the fungicide benomyl or water and added to trays containing two L. corniculatus or one L. corniculatus and one Brassica napus (a nonmycotrophic species). Leaves of target L. corniculatus were undamaged or clipped five times over 40 days. Plants were harvested 5, 18, or 36 days after last clipping. Interspecific competition was the dominant effect at all harvests: B. napus greatly depressed growth of its neighbor. Benomyl depressed VAM colonization only in the first harvest, and growth reduction associated with depressed colonization diminished over time. Clipping reduced growth most in plants paired with conspecifics, but growth depression was transient. Benomyl and clipping reduced mass of root nodules in the first harvest. Benomyl reduced root mass in nontarget (competitor) L. corniculatus, but plants recovered with time. Neither benomyl nor clipping of the target plant affected B. napus. Interactions were few, indicating that the effects of factors were mostly additive. Key words: VAM fungi, resource allocation, nonmycotrophic competitor.

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.

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.

scholarly journals Vesicular-arbuscular Mycorrhizal Peat-based Substrates Enhance Symbiosis Establishment and Growth of Three Micropropagated Species

1993 ◽  
Vol 118 (6) ◽  
pp. 896-901 ◽  
Author(s):  
H. Wang ◽  
S. Parent ◽  
A. Gosselin ◽  
Y. Desjardins
Keyword(s):  
Glomus Intraradices ◽  
Arbuscular Mycorrhizal ◽  
Dry Weight ◽  
Gerbera Jamesonii ◽  
Subsequent Growth ◽  
Vam Fungi ◽  
Vesicular Arbuscular ◽  
Ornamental Species ◽  
Term Benefit

Micropropagated plantlets of Gerbera jamesonii H. Bolus ex Hook. F. `Terra Mix', Nephrolepis exaltata (L.) Schott `Florida Ruffles', and Syngonium podophyllum Schott `White Butterfly' were inoculated with two vesicular-arbuscular mycorrhizal (VAM) fungi, Glomus intraradices Schenck and Smith and G. vesiculiferum Gerderman and Trappe. They were potted in three peat-based media to determine the effects of mycorrhizal peat substrate on acclimatization and subsequent growth of micropropagated plantlets under greenhouse conditions. Symbiosis was established between the three ornamental species and VAM fungi within 4 to 8 weeks of culture in the greenhouse, but not during acclimatization. Mortality of Gerbera and Nephrolepis mycorrhizal plantlets was reduced at week 8 compared to the noninoculated control. A peat-based substrate low in P and with good aeration improved VAM fungi spread and efficiency. Mycorrhizal substrates had a long-term benefit of increasing leaf and root dry weight of Gerbera and Nephrolepis. Mycorrhizal Gerbera plants flowered significantly faster than non-mycorrhizal plants.

scholarly journals Influence of Inoculation with Vesicular-Arbuscular Mycorrhizae on Posttransplant Growth of Prairie Forb Seedlings

2000 ◽  
Vol 10 (4) ◽  
pp. 768-772
Author(s):  
Ricky D. Kemery ◽  
Michael N. Dana
Keyword(s):  
Growth Response ◽  
Arbuscular Mycorrhizae ◽  
Arbuscular Mycorrhizal ◽  
Fungal Species ◽  
Vam Fungi ◽  
Purple Coneflower ◽  
Echinacea Pallida ◽  
Vesicular Arbuscular ◽  
Positive Growth ◽  
Prairie Soil

The objectives of this study were to compare the growth of prairie forb seedlings inoculated with vesicular-arbuscular mycorrhizal (VAM) fungi to noninoculated seedlings transplanted to a highway right-of-way and to evaluate the effect of different VAM fungal species or combinations on posttransplant seedling growth. Four species of prairie forbs: pale-purple coneflower (Echinacea pallida Nutt.), prairie blazingstar (Liatris pycnostachya Michx.), prairie phlox (Phlox pilosa L.), and gray-headed coneflower [Ratibida pinnata (Venten.) Barnh.], were grown in greenhouse mix and inoculated with Gigaspora margarita Becker and Hall, or Glomus interadicies Schenk and Smith, or with a native Indiana prairie soil inoculum, or with a mix of all three. They were transplanted to a highway site in June, 1994. Only gray-headed coneflower exhibited a positive growth response to VAM inoculation. Inoculation of gray-headed coneflower with G. margarita produced the largest growth response by the end of the experiment.

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.

scholarly journals The effect of vesicular-arbuscular mycorrhizal inoculation on the growth and root colonization of ten strawberry cultivars

1992 ◽  
Vol 1 (5) ◽  
pp. 527-535 ◽  
Author(s):  
Mauritz Vestberg
Keyword(s):  
Root Colonization ◽  
Arbuscular Mycorrhizal ◽  
Dry Weight ◽  
Mycorrhizal Dependency ◽  
Vam Fungi ◽  
Shoot Dry Weight ◽  
Vesicular Arbuscular ◽  
Mycorrhizal Inoculation ◽  
Dependency Index ◽  
Strawberry Cultivars

Ten strawberry cultivars, four early maturing, three late maturing and three “special” cultivars, were inoculated with six strains of vesicular-arbuscular mycorrhizal (VAM) fungi in a pot experiment. Growth effects and colonization of the VAM fungi were studied. Three strains, Glomus macrocarpum V3, G. mosseae Rothamsted and G. sp. V4, were highly efficient, causing significant growth increases in most cultivars. ’Jonsok’ showed the highest mycorrhizal dependency index, 648, and ’Ostara’ the lowest, 269, for the mean response of all six fungi. The fungal strains which increased shoot growth the most also increased the runner plant formation the most. Early cultivars showed higher colonization percentages than late maturing cultivars. Sporulation of the introduced VAM fungi was on average more abundant in early and special cultivars than in late cultivars. Root colonization and strawberry shoot dry weight correlated significantly in most cultivars, but the correlation between colonization and runner formation was generally poor.

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.

Symbiotic Vesicular-Arbuscular Mycorrhizae Influence Maximum Rates of Photosynthesis in Tropical Tree Seedlings Grown Under Elevated CO2

1997 ◽  
Vol 24 (2) ◽  
pp. 185 ◽  
Author(s):  
C. E. Lovelock ◽  
D. Kyllo ◽  
M. Popp ◽  
H. Isopp ◽  
A. Virgo ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Arbuscular Mycorrhizae ◽  
Forest Tree ◽  
Sink Strength ◽  
Tree Seedlings ◽  
Va Mycorrhizae ◽  
Co2 Concentrations ◽  
Vesicular Arbuscular ◽  
Mycorrhizal Plants ◽  
Atmospheric Co2 Concentrations

To investigate the importance of phosphorus and carbohydrate concentrations in influencing photosynthetic capacity of tropical forest tree seedlings under elevated CO2, we grew seedlings of Beilschmiedia pendula (Sw.) Hemsl. (Lauraceae) under elevated CO2 concentrations either with or without vesicular-arbuscular (VA) mycorrhizae. VA-mycorrhizae increased phosphorus concentrations in all plant organs (leaves, stems and roots). Maximum rates of photosynthesis (Amax) measured under saturating levels of CO2 and light were correlated with leaf phosphorus concentrations. VA-mycorrhizae also increased leaf carbohydrate concentrations, particularly under elevated CO2, but levels were low and within the range observed in naturally occurring forest species. Root carbohydrate concentrations were reduced in VA-mycorrhizal plants relative to non-mycorrhizal plants. These results indicate an important role for VA-mycorrhizae in controlling photosynthetic rates and sink strength in tropical trees, and thus in determining their response to future increases in atmospheric CO2 concentrations.

Sign in / Sign up

Export Citation Format

Share Document