Slow arbuscular mycorrhizal colonisation of field-grown cotton caused by environmental conditions in the soil

The formation of arbuscular mycorrhizas (AM) can result in positive, neutral or negative responses in the growth and mineral nutrition of host plants, particularly that of P, Zn and other micronutrients. This study examined the growth and nutritional responses of 15 agriculturally important plant species, including cereals, legumes and vegetables, with and without inoculation with the AM fungus (AMF) Rhizophagus irregularis. Furthermore, we explored whether the responses differed between different functional groups of plants such as monocots and dicots, C3 and C4 plants, and N-fixing and non-N-fixing plants. We found that that mycorrhizal colonisation of roots, plant growth and plant nutrient responses differed between plant species. Among the species analysed, leek (Allium ampeloprasum L. var. porrum) was the most mycorrhiza-responsive, displaying the highest mycorrhizal colonisation and biomass response, and the greatest increases in most mineral nutrients. In other plant species, the concentration of P, Cu, Zn and S were generally enhanced by inoculation with AMF. Furthermore, ionomes differed more greatly between plant species than in response to inoculation with AMF. This research further improves our understanding of the responses of different and diverse plant species to the formation of AM in terms of growth and ionomics under standardised growth conditions. The results of this study may be used in further studies and to inform agricultural practices.

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Field inoculation with arbuscular mycorrhizal fungi in rehabilitation of mine sites with native vegetation, including Acacia spp.

Australian Systematic Botany ◽

10.1071/sb02004 ◽

2003 ◽

Vol 16 (1) ◽

pp. 131 ◽

Cited By ~ 15

Author(s):

J. Bell ◽

S. Wells ◽

D. A. Jasper ◽

L. K. Abbott

Keyword(s):

Mycorrhizal Fungi ◽

Field Experiments ◽

Arbuscular Mycorrhizal ◽

Am Fungi ◽

Native Plant ◽

Field Inoculation ◽

Native Plant Species ◽

Mycorrhizal Colonisation ◽

Mine Sites ◽

Fertiliser Application

Field experiments were conducted at rehabilitation sites at two contrasting mines in Western Australia. At both mines, Acacia spp. are important components of the rehabilitation ecosystem. At a mineral sands mine near Eneabba, dry-root inoculum of the arbuscular mycorrhizal (AM) fungus Glomus invermaium (WUM 10) was introduced into riplines with three rates of phosphate fertiliser application. Plants were assessed for mycorrhizal colonisation and phosphorus status. There was no plant growth benefit from inoculation. A considerable number of infective propagules of indigenous AM fungi was already present in the topsoil. The inoculant fungus as well as the indigenous AM fungi formed mycorrhizas, but only in a small number of Acacia and other native plant species. In a study of AM fungal inoculation at a gold mine rehabilitation site at Boddington, dry-root inoculum of G.�invermaium was applied to riplines prior to seeding. Despite apparently ideal environmental conditions, colonisation of native seedlings was limited. Possible reasons for this were investigated in further experiments that addressed environmental factors such as soil temperature and moisture and factors such as the age of the plant and presence of a colonised cover crop. Inoculum remained infective even under moist conditions in field soil for at least 4 months. Its infectivity decreased in parallel with falling temperatures. However, the level of infectivity present did not ensure extensive colonisation of native plants such as Acacia seedlings in the field. Susceptibility of Acacia seedlings to colonisation by AM fungi appeared to be seasonal, as colonisation increased with increasing daytime temperatures and daylight hours.

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Phosphorus nutrition of ectomycorrhizal and arbuscular mycorrhizal tree seedlings from a lowland tropical rain forest in Korup National Park, Cameroon

Journal of Tropical Ecology ◽

10.1017/s0266467498000054 ◽

1998 ◽

Vol 14 (1) ◽

pp. 47-61 ◽

Cited By ~ 34

Author(s):

BERNARD MOYERSOEN ◽

IAN J. ALEXANDER ◽

ALASTAIR H. FITTER

Keyword(s):

National Park ◽

Growth Promotion ◽

Phosphorus Uptake ◽

Arbuscular Mycorrhizal ◽

Arbuscular Mycorrhizas ◽

Phosphorus Availability ◽

Tropical Rain Forests ◽

High Phosphorus ◽

Korup National Park ◽

Mycorrhizal Colonisation

The relationship between mycorrhizal colonisation and phosphorus acquired by seedlings of the arbuscular mycorrhizal tree Oubanguia alata Bak f. (Scytopetalaceae) and the ectomycorrhizal tree Tetraberlinia moreliana Aubr. (Caesalpiniodeae) was evaluated at low and high inorganic phosphorus availability. AM colonisation was positively correlated with phosphorus uptake by O. alata at low, but not at high phosphorus availability. Seedlings growth was positively related to arbuscular mycorrhizal colonisation at both low and high phosphorus availability, suggesting that growth promotion by arbuscular mycorrhizas is not simply related to an increase of phosphorus uptake. In contrast, phosphorus uptake by T. moreliana was correlated with EM colonisation at both low and high phosphorus availability, but there was no relationship between growth and ectomycorrhizal colonisation. Promotion of phosphorus uptake by arbuscular mycorrhizas and ectomycorrhizas at low phosphorus availability is consistent with the co-occurrence of the two types of mycorrhiza in tropical rain forests where available soil phosphorus is low. However, ectomycorrhizal colonisation may also be of advantage where inputs of phosphorus rich litter raise the phosphorus status of the soil, as seen in the groves of ectomycorrhizal trees in Korup National Park, and may be one of the factors reinforcing local dominance by these trees.

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