Mycorrhizal Inoculation Treatments Research Articles

AM fungi inoculation and addition of microbially‐treated dry olive cake‐enhanced afforestation of a desertified Mediterranean site

AbstractA field experiment was carried out to compare the effectiveness of inoculation with three arbuscular mycorrhizal (AM) fungi, namely Glomus intraradices Schenck & Smith, Glomus deserticola (Trappe, Bloss. & Menge) and Glomus mosseae (Nicol & Gerd.) Gerd. & Trappe, and the addition of Aspergillus niger‐treated dry olive cake (DOC) in the presence of rock phosphate, in increasing root nitrate reductase (NR) and acid phosphatase activities, mycorrhizal colonization, plant growth and nutrient uptake in Dorycnium pentaphyllum L. seedlings afforested in a semiarid degraded soil. Three months after planting, both the addition of fermented DOC and the mycorrhizal inoculation treatments had increased root NR activity significantly, particularly the inoculation with G. deserticola (by 75 per cent with respect to non‐inoculated plants), but they had no effect on root acid phosphatase. Mycorrhizal inoculation treatments with G. deserticola or G. mosseae on their own were even more effective than the addition of fermented DOC alone in improving the growth and (NPK) foliar nutrients of D. pentaphyllum plants. The combined treatment involving the application of microbially‐treated agrowastes and mycorrhizal inoculation with AM fungi, particularly with G. mosseae, can be proposed as a successful revegetation strategy for D. pentaphyllum in P‐deficient soils under semiarid Mediterranean conditions. Copyright © 2004 John Wiley & Sons, Ltd.

Comparing the effectiveness of mycorrhizal inoculation and amendment with sugar beet, rock phosphate and Aspergillus niger to enhance field performance of the leguminous shrub Dorycnium pentaphyllum L.

A field experiment was undertaken to evaluate the effectiveness of mycorrhizal inoculation with Glomus intraradices (Schenck & Smith) or Glomus deserticola (Trappe, Bloss. & Menge) and the addition of sugar beet (SB), rock phosphate and Aspergillus niger with respect to the establishment of Dorycnium pentaphyllum L. seedlings, in a semiarid Mediterranean area, and the improvement of the physical-chemical, biochemical and biological properties of the soil. Eighteen months after planting, amended soil had higher available phosphorus and aggregate stability levels than control soil (165 and 157%, respectively). All assayed treatments had higher soil total carbohydrates and water soluble C values and enzyme activities (dehydrogenase, urease, acid phosphatase and β-glucosidase), and lower soil pH and bulk density than control soil. Biomass C and dehydrogenase, urease and β-glucosidase activities of the rhizosphere of G. deserticola-inoculated plants were higher than those of the rhizosphere of G. intraradices-inoculated plants. Mycorrhizal inoculation treatments stimulated significantly the production of shoot biomass, to a higher extent than the addition of the amendment alone to soil or the combined treatment. The highest levels of mycorrhizal colonisation and of foliar N and K were recorded in the seedlings inoculated with G. deserticola. The shoot biomass of G. deserticola-inoculated D. pentaphyllum plants was greater (about 219% with respect to control plants) than that of G. intraradices (about 116% with respect to control plants).

Antioxidant enzyme activities in shoots from three mycorrhizal shrub species afforested in a degraded semi‐arid soil

Mycorrhizae may help plants to thrive in Mediterranean semi‐arid ecosystems by altering antioxidant enzyme activities. Our objective was to determine the influence of mycorrhizal inoculation with an allochthonous arbuscular mycorrhizal (AM) fungus, Glomus claroideum, Schenck & Smith, or with a mixture of native AM fungi, on the activity of antioxidant enzymes from shoots of Olea europaea L. ssp. sylvestris, Retama sphaerocarpa (L.) Boissier and Rhamnus lycioides L. seedlings afforested in a degraded Mediterranean semi‐arid soil. One year after planting, shoot biomass of inoculated O. europaea seedlings was about 630%, of non‐inoculated plants. Shoot biomass of G. claroideum‐colonized R. sphaerocarpa was greater than that of seedlings inoculated with the mixed native AM fungi after 12 months. Inoculation with a mix of native AM fungi was the most effective treatment for increasing shoot biomass and N, P and K contents in shoot tissues of R. lycioides. Both mycorrhizal inoculation treatments increased the nutrient contents in shoots of O. europaea and R. lycioides. In O. europaea plants, the inoculation treatments increased catalase, ascorbate peroxidase and dehydroascorbate reductase activities, but not monodehydroascorbate reductase and glutathione reductase activities. Inoculation with G. claroideum increased the activities of all antioxidant enzymes in R. sphaerocarpa. Monodehydroascorbate reductase, glutathione reductase and superoxide dismutase activities in R. lycioides leaves were preferentially increased by inoculation with the mixture of native AM fungi. This work support the view that increased antioxidant enzyme activities could be involved, at least in part, in the beneficial effects of mycorrhizal colonization on the performance of shrub species grown under semi‐arid Mediterranean conditions.

Assessing the effectiveness of mycorrhizal inoculation and soil compost addition for enhancing reafforestation with Olea europaea subsp. sylvestris through changes in soil biological and physical parameters

A field experiment was carried out in a semiarid area to assess the influence of mycorrhizal inoculation and soil compost addition on establishment of Olea europaea seedlings. Associated changes in soil biological and physical parameters were observed. One year after planting, both reafforestation methods had significantly improved the soil structure. Thus, mycorrhizal inoculation increased soil aggregate stability (AS) and composted residue addition decreased soil bulk density (BD). A significant correlation ( P<0.05) was found between BD and several biochemical parameters (dehydrogenase, protease and β-glucosidase activities), indicating that soil biological agents play an important role in improving soil structure. The growth of O. europaea was significantly enhanced by both composted organic residue addition and mycorrhizal inoculation treatment. The increase in mycorrhizal O. europaea seedling growth may be due to the positive influence of mycorrhiza on soil AS. The combination of high fertility levels and low BD also favoured the growth of O. europaea in compost-amended soils. Finally, the positive interaction between the two methods in relation to seedling height growth could be related to the capacity of the fungus to increase nutrient uptake from the composted residue.

Crescimento e absorção de fósforo em plantas de Eucalyptus grandis associadas a fungos micorrízicos em diferentes doses de fósforo e potenciais de água do solo

Avaliaram-se a produção de parte aérea (MS), a absorção (CP) e a eficiência de utilização de fósforo (EUP) por plantas de Eucalyptus grandis inoculadas com Glomus etunicatum (Ge) e, ou, Pisolithus tinctorius (Pt), em diferentes combinações entre doses de P e potenciais hídricos do solo (ψ), utilizando-se técnica de raízes subdivididas em vasos geminados, em casa de vegetação. Um dos vasos do conjunto geminado continha os tratamentos em arranjo fatorial de duas doses de P (P60 e P120, correspondentes a adições de 60 e 120 mg dm-3 de solo), três ψ (-10, -40 e -300 kPa) e quatro tratamentos com inóculos fúngicos (não inoculado, Ge, Pt, Ge + Pt). Outro vaso do conjunto continha 4,5 litros de solução nutritiva, sem P. Independentemente da dose de P adicionada, a colonização por Ge foi reduzida com a diminuição do ψ. Quanto à colonização por Pt, observou-se ausência de resposta a ψ em P60 e aumento em P120. A colonização ectomicorrízica foi reduzida quando Pt foi inoculado concomitantemente a Ge. Aumentos do CP, em função do incremento do ψ, foram observados em P60 e P120. No entanto, MS e EUP responderam positivamente à elevação de ψ apenas em P120. A inoculação isolada com Ge não apresentou efeito sobre as plantas, nas combinações entre ψ e P. A colonização por Pt apresentou efeitos diferenciados sobre as plantas, dependendo das condições de ψ e P no solo. Na combinação P60 e -300 kPa, correspondente à situação de menor disponibilidade de P, observou-se efeito deletério da colonização por Pt, isolada ou concomitantemente com Ge, sobre a EUP das plantas. Efeitos positivos da inoculação isolada com Pt sobre o CP foram observados nas combinações entre P120 e ψ de -10 kPa e -40 kPa, embora apenas na segunda situação este maior CP tenha sido acompanhado de incremento da MS.

Response of ectomycorrhizal and nonmycorrhizal pitch pine (Pinusrigida) seedlings to nutrient supply and aluminum: growth and mineral nutrition

Mycorrhizal colonization and nutrient supply may have important effects on aluminum toxicity in trees grown on acidic, nutrient-poor soils. The interacting effects of mycorrhizal inoculation, nutrient level, and Al treatment on growth and mineral nutrition of pitch pine (Pinusrigida Mill.) seedlings grown with and without the ectomycorrhizal fungus Pisolithustinctorius (Pers.) Coker &amp; Couch were determined. The seedlings were grown for 66 days in sand irrigated with 0.1- or 0.2-strength nutrient solution (pH 3.8) containing 0, 10, or 20 mg/L Al (0, 0.37, or 0.74 mM). Across nutrient and Al levels total dry weight of ectomycorrhizal (ECM) seedlings was 75% greater than that of nonmycorrhizal (NM) seedlings. Doubling the nutrient level increased the dry weight of NM seedlings by 120%, versus 60% for ECM seedlings. Aluminum reduced root and shoot growth in NM seedlings, but had no effect on shoot growth and only a marginally significant effect on root growth of ECM seedlings. Shoot growth of NM seedlings was more sensitive to Al than root growth. Increased growth of NM seedlings by doubling the nutrient level was least at the highest Al level. Symptoms of Al toxicity in roots (dark, stunted tips) occurred at a lower Al level in NM than ECM seedlings. A strong relationship was not found between Al toxicity and concentrations of Mg and Ca in roots and needles. Enhancement of growth resulting from increased uptake of nutrients due to mycorrhizal inoculation (and) or an increased level of nutrients was the overriding factor affecting the response of pitch pine seedlings to Al.

Sulfur supply and the formation of vesicular-arbuscular mycorrhizas by Glomus fasciculatum on subterranean clover

Sulfur supply and the formation of vesicular-arbuscular mycorrhizas by Glomus fasciculatum on subterranean clover

Influence of Mine Spoil Type, Fertilizer, and Mycorrhizae on Pines Seeded in Greenhouse Trays

AbstractGrowth and mycorrhizal colonization of surface‐seeded pine (Pinus sp.) as affected by two different mine spoil types (siltstone and sandstone), two fertilizer treatments (control and 100 kg/ha each of N, P, and K), and three mycorrhizal inoculation treatments [control, 56 kg/ha pine litter, and 250 g/ha Pisolithus tinctorius (Pers.) Coker and Couch (PT) basidiospores] were evaluated in a greenhouse experiment. Emergence was highest (12, 55, and 34% for P. strobus, P. virginiana, and P. taeda, respectively) in nonfertilized siltstone, but growth performance was greatest in fertilized sandstone. Fertilization increased shoot weight of white, Virginia, and loblolly pine growing in sandstone spoil two‐, ten‐, and eightfold, respectively. Fertilization had no effect on seedlings growing in siltstone spoil. Mycorrhizal inoculation of Virginia pine was effective in sandstone but not in siltstone spoil. Addition of pine litter and Pisolithus tinctorius spores to sandstone spoil increased the percentage of colonized Virginia pines by 27 and 33%, respectively. Inoculation had no effect on the number of white and loblolly trees colonized.