Evaluation of the infectivity and effectiveness of indigenous vesicular–arbuscular fungal populations in some agricultural soils in Burgundy

1985 ◽  
Vol 63 (9) ◽  
pp. 1521-1524 ◽  
Author(s):  
V. Gianinazzi-Pearson ◽  
S. Gianinazzi ◽  
A. Trouvelot
Keyword(s):  
Plant Growth ◽  
Physicochemical Properties ◽  
Root Colonization ◽  
Agricultural Soils ◽  
Vesicular Arbuscular ◽  
Fungal Populations ◽  
Fungal Inoculation ◽  
Colonization Rates ◽  
Different Soils

Infectivity, measured as propagule numbers and root colonization rates, and effects on plant growth of indigenous vesicular–arbuscular fungal populations varied among soils from 10 different localities in Burgundy. These three characteristics of the populations were not necessarily related to each other nor to the physicochemical properties of the soils. It was possible, using relatively simple methods, to assess the potential for vesicular–arbuscular fungal inoculation in the different soils.

scholarly journals Measurement of Physicochemical Properties, Electrical and Thermal Conductivity of Wood Ash for Effective Soil Amendment

2021 ◽  
Vol 11 (2) ◽  
pp. 176
Author(s):  
M O Kanu ◽  
Gabriel Wirdzelii Joseph ◽  
Israel George
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Plant Growth ◽  
Physicochemical Properties ◽  
Physical Properties ◽  
Soil Amendment ◽  
Agricultural Soils ◽  
Wood Ash ◽  
Heat Energy ◽  
Total Dissolved Solid

The ability of the soil to regulate heat energy is important for plant growth, soil texture and strength. Many agricultural soils are acidic in nature which tends to limit plant growth and microbial activity. Aside from agricultural lime, wood ash is used to amend physical and physicochemical properties of the soil. To maintain the soil hydraulic and physicochemical properties and to increase plant yield, it is important to know the physicochemical and physical properties of the ash used. The physiochemical and physical properties vary across various plant species. Ash samples from seven different plants were used for this study. The Horiba metre was used to measure the electrical conductivity, pH, Total Dissolved Solid (TDS) and salinity of the samples, while the Lees Disc apparatus was used to measure the thermal conductivity of the samples. The study revealed that moringa olieferra ash has the highest salinity, TDS and Electrical conductivity, while azadichta indica and tiobroma cacoa have least pH. Also, Kyah seleelygalisis and azadichta indica had the highest and lowest thermal conductivity respectively.

Decline of vesicular-arbuscular mycorrhizae in long fallow disorder of field crops and its expression in phosphorus deficiency of sunflower

1987 ◽  
Vol 38 (5) ◽  
pp. 847 ◽  
Author(s):  
JP Thompson
Keyword(s):  
Plant Growth ◽  
Root Length ◽  
Mycorrhizal Fungi ◽  
Root Colonization ◽  
Mycorrhizal Colonization ◽  
Poor Growth ◽  
Plant Weight ◽  
P Deficiency ◽  
Vesicular Arbuscular ◽  
Fallow Soil

Poor growth of crops after long fallows (> 12 months) in cracking clay soils of the northern areas of the Australian grain belt is known as 'long fallow disorder'. Various crop species, including wheat (Triticum aestivum L.), chickpea (Cicer arietinum L.), grain sorghum [Sorghum bicolor (L.) Moench], sudan grass [Sorghum sudanense (Piper) Stapf], sunflower (Helianthus annuus L.), soybean [Glycine max (L.) Merr.] and maize (Zea mays L.), had less root colonization with vesicular-arbuscular mycorrhizal (VAM) fungi and plant weight after long fallows than after short fallows. An experiment was conducted with a phosphorus-deficient soil that had been either fallowed for 3 years or sequentially cropped to cotton, sorghum and sunflower. Cropped soil had more mycorrhizal propagules consisting of intact spores and colonized roots than long fallow soil. In the glasshouse, mycorrhizal colonization of sunflower (cv. Hysun 33) developed quickly in previously cropped soil to peak at 80% of root length at 72 days (flowering), but in long fallow soil it proceeded slowly, attaining 35% of root length at 72 days. Inoculation of long fallow soil with 20% w/w cropped soil resulted in extensive root colonization (89% at 72 days), eliminated P deficiency symptoms and more than doubled plant growth and final P uptake. Inoculation with similar soil treated with gamma radiation to kill propagules of mycorrhizal fungi had no effect on plant growth. Sunflower grew extremely poorly in irradiated soil with considerable leaf necrosis due to P deficiency. Reinoculation with cropped soil resulted In high levels of mycorrhizal colonization and good plant growth. It was concluded that long fallow disorder is caused by a decline in viable propagules of mycorrhizal fungi during fallowing, resulting in poor root colonization and symbiotic effectiveness of a subsequent crop. Fertilizing with phosphorus (50 mg P/kg soil) delayed the development of mycorrhizal colonization, but increased final lengths of colonized roots at 72 days. Zinc fertilizer (15 mg Zn/kg soil) slightly improved mycorrhizal colonization, and basal fertilizer (N, K, S, Ca) substantially improved colonization in long fallow soil inoculated with cropped soil.

scholarly journals Vesicular-arbuscular mycorrhizal fungus inoculation of sour orange seedlings in Barbados

1969 ◽  
Vol 72 (2) ◽  
pp. 191-199
Author(s):  
Stan Michelini ◽  
Stan Nemec
Keyword(s):  
Plant Growth ◽  
Methyl Bromide ◽  
Glomus Intraradices ◽  
Agricultural Soils ◽  
Mycorrhizal Fungus ◽  
Arbuscular Mycorrhizal ◽  
Vam Fungi ◽  
Vesicular Arbuscular ◽  
Glomus Species ◽  
Vigorous Plant

A citrus seedbed was established August 1984 on the west coast of Barbados. Before being planted and inoculated with vesicular-arbuscular mycorrhizal (VAM) fungi, one-half the seedbed was fumigated with methyl bromide; the other half was untreated. Four weeks after fumigation, four treatments, Glomus intraradices, G. mosseae, indigenous VAM fungi, and a noninoculated control were established in each half of the test. Early vigorous plant growth in the nonfumigated half of the plot suggested that indigenous VAM may have colonized and stimulated plant growth earlier than the treatments in the fumigated portion. Three months after inoculation, plants in both portions of the plot were growing well. In the fumigated area, application of two Glomus species, which were introduced from Florida, resulted in a significant improvement in plant growth over the control. This occurred in spite of the fact that infection levels in control roots were similar to those in inoculated roots. This study suggests that, when possible, alternative pesticides not harmful to VAM fungi should be used in place of methyl bromide fumigation to conserve these fungi in agricultural soils.

The role of vesicular arbuscular mycorrhizal fungi in agriculture and the selection of fungi for inoculation

1982 ◽  
Vol 33 (2) ◽  
pp. 389 ◽  
Author(s):  
LK Abbott ◽  
AD Robson
Keyword(s):  
Plant Growth ◽  
Nutrient Uptake ◽  
Mycorrhizal Fungi ◽  
Large Scale ◽  
Agricultural Soils ◽  
Va Mycorrhizas ◽  
Vesicular Arbuscular ◽  
Field Soils ◽  
Va Mycorrhizal Fungi ◽  
Mycorrhizal Roots

Vesicular arbuscular (VA) mycorrhizas are roots infected with particular soil fungi which form symbiotic associations. It is often assumed that VA mycorrhizal fungi could be used to increase the efficiency of phosphate fertilizers in agriculture. Our principal concern is the question: 'Can the symbiosis be exploited on a large scale?'. VA mycorrhizas increase nutrient uptake, and hence plant growth, by shortening the distance that nutrients must diffuse through soil to the root. Mycorrhizal roots do not appear to have a lower threshold concentration of nutrients for absorption from solution than do non-mycorrhizal roots. Most soils contain VA mycorrhizas. Hence, for plant growth to respond to inoculation with VA mycorrhizal fungi, agricultural soils must have either a low incidence of indigenous VA mycorrhizal fungi or alternatively, species which are less effective than the inoculant fungi in their ability to stimulate nutrient uptake by plants. The distribution of species of VA mycorrhizal fungi varies with climatic and edaphic environment, as well as with land use. However, the factors which control their distribution are poorly understood. Differences among VA mycorrhizal fungi in their ability to increase nutrient uptake appear to be due to differences in their ability to form mycorrhizas rapidly and extensively. The importance of other differences among the fungi, such as in the absorption of nutrients from solution or in the distribution and amount of external mycelium, has yet to be clearly demonstrated. Inoculant VA mycorrhizal fungi must be capable of persisting in soils at a high inoculum potential, as well as being able to increase nutrient uptake. Until now, little attention has been paid to characteristics which enable the fungi to persist after inoculation. We are critical of many of the methods employed in experiments aimed at selecting 'efficient' VA mycorrhizal fungi. For practical purposes, selection can only be achieved by means of comparisons performed in untreated field soils, with phosphorus supply limiting plant growth. Because the form of inoculum can affect the relative abilities of VA mycorrhizal fungi to infect and improve plant growth, appropriate inocula are needed for each agricultural situation. The survival of many species of fungi in various types of inocula requires further study so that procedures can be developed for introducing particular fungi into agricultural soils. This review emphasizes many gaps in our knowledge. For example, we need more information on how and to what extent species or strains of VA mycorrhizal fungi differ in their ability to increase plant growth. We know even less about their beneficial effects in years following that of field inoculation. The ecology of indigenous VA mycorrhizal fungi in field soils has also been largely neglected. These and other deficiencies preclude any immediate recommendations for large-scale inoculation with selected VA mycorrhizal fungi.

scholarly journals Effect of Low Zeolite Doses on Plants and Soil Physicochemical Properties

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2617
Author(s):  
Alicja Szatanik-Kloc ◽  
Justyna Szerement ◽  
Agnieszka Adamczuk ◽  
Grzegorz Józefaciuk
Keyword(s):  
Plant Growth ◽  
Physicochemical Properties ◽  
Cation Exchange ◽  
Surface Area ◽  
Cation Exchange Capacity ◽  
N Fertilization ◽  
Exchange Capacity ◽  
First Year ◽  
Soil Physicochemical Properties ◽  
Water Holding

Thousands of tons of zeolitic materials are used yearly as soil conditioners and components of slow-release fertilizers. A positive influence of application of zeolites on plant growth has been frequently observed. Because zeolites have extremely large cation exchange capacity, surface area, porosity and water holding capacity, a paradigm has aroused that increasing plant growth is caused by a long-lasting improvement of soil physicochemical properties by zeolites. In the first year of our field experiment performed on a poor soil with zeolite rates from 1 to 8 t/ha and N fertilization, an increase in spring wheat yield was observed. Any effect on soil cation exchange capacity (CEC), surface area (S), pH-dependent surface charge (Qv), mesoporosity, water holding capacity and plant available water (PAW) was noted. This positive effect of zeolite on plants could be due to extra nutrients supplied by the mineral (primarily potassium—1 ton of the studied zeolite contained around 15 kg of exchangeable potassium). In the second year of the experiment (NPK treatment on previously zeolitized soil), the zeolite presence did not impact plant yield. No long-term effect of the zeolite on plants was observed in the third year after soil zeolitization, when, as in the first year, only N fertilization was applied. That there were no significant changes in the above-mentioned physicochemical properties of the field soil after the addition of zeolite was most likely due to high dilution of the mineral in the soil (8 t/ha zeolite is only ~0.35% of the soil mass in the root zone). To determine how much zeolite is needed to improve soil physicochemical properties, much higher zeolite rates than those applied in the field were studied in the laboratory. The latter studies showed that CEC and S increased proportionally to the zeolite percentage in the soil. The Qv of the zeolite was lower than that of the soil, so a decrease in soil variable charge was observed due to zeolite addition. Surprisingly, a slight increase in PAW, even at the largest zeolite dose (from 9.5% for the control soil to 13% for a mixture of 40 g zeolite and 100 g soil), was observed. It resulted from small alterations of the soil macrostructure: although the input of small zeolite pores was seen in pore size distributions, the larger pores responsible for the storage of PAW were almost not affected by the zeolite addition.

scholarly journals Micro-Landscape Dependent Changes in Arbuscular Mycorrhizal Fungal Community Structure

2021 ◽  
Vol 11 (11) ◽  
pp. 5297
Author(s):  
Stavros D. Veresoglou ◽  
Leonie Grünfeld ◽  
Magkdi Mola
Keyword(s):  
Community Structure ◽  
Mycorrhizal Fungi ◽  
Root Colonization ◽  
Environmental Parameters ◽  
Arbuscular Mycorrhizal ◽  
Fungal Community Structure ◽  
High Connectivity ◽  
Spatio Temporal ◽  
Arbuscular Mycorrhizal Fungal ◽  
Colonization Rates

The roots of most plants host diverse assemblages of arbuscular mycorrhizal fungi (AMF), which benefit the plant hosts in diverse ways. Even though we understand that such AMF assemblages are non-random, we do not fully appreciate whether and how environmental settings can make them more or less predictable in time and space. Here we present results from three controlled experiments, where we manipulated two environmental parameters, habitat connectance and habitat quality, to address the degree to which plant roots in archipelagos of high connectivity and invariable habitats are colonized with (i) less diverse and (ii) easier to predict AMF assemblages. We observed no differences in diversity across our manipulations. We show, however, that mixing habitats and varying connectivity render AMF assemblages less predictable, which we could only detect within and not between our experimental units. We also demonstrate that none of our manipulations favoured any specific AMF taxa. We present here evidence that the community structure of AMF is less responsive to spatio-temporal manipulations than root colonization rates which is a facet of the symbiosis which we currently poorly understand.

scholarly journals A prospectus of plant growth promoting endophytic bacterium from orchid (Vanda cristata)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Sujit Shah ◽  
Krishna Chand ◽  
Bhagwan Rekadwad ◽  
Yogesh S. Shouche ◽  
Jyotsna Sharma ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root Colonization ◽  
Endophytic Bacterium ◽  
Epifluorescence Microscopy ◽  
In Vitro Cultivation ◽  
Rrna Gene ◽  
Bacillus Spp ◽  
Plant Growth Promoting ◽  
Growth Promoting

Abstract Background A plant growth-promoting endophytic bacterium PVL1 isolated from the leaf of Vanda cristata has the ability to colonize with roots of plants and protect the plant. PVL1 was isolated using laboratory synthetic media. 16S rRNA gene sequencing method has been employed for identification before and after root colonization ability. Results Original isolated and remunerated strain from colonized roots were identified as Bacillus spp. as per EzBiocloud database. The presence of bacteria in the root section of the plantlet was confirmed through Epifluorescence microscopy of colonized roots. The in-vitro plantlet colonized by PVL1 as well as DLMB attained higher growth than the control. PVL1 capable of producing plant beneficial phytohormone under in vitro cultivation. HPLC and GC-MS analysis suggest that colonized plants contain Indole Acetic Acid (IAA). The methanol extract of Bacillus spp., contains 0.015 μg in 1 μl concentration of IAA. PVL1 has the ability to produce antimicrobial compounds such as ethyl iso-allocholate, which exhibits immune restoring property. One-way ANOVA shows that results were statistically significant at P ≤ 0.05 level. Conclusions Hence, it has been concluded that Bacillus spp. PVL1 can promote plant growth through secretion of IAA during root colonization and ethyl iso-allocholate to protect plants from foreign infections. Thus, this study supports to support Koch’s postulates of bacteria establishment.

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