STUDIES ON THE RELATIONSHIPS BETWEEN NEMATODES AND OTHER SOIL MICROORGANISMS: IV. INCIDENCE OF NEMATODE-TRAPPING FUNGI IN THE VICINITY OF PLANT ROOTS

1965 ◽  
Vol 11 (3) ◽  
pp. 491-495 ◽  
Author(s):  
E. A. Peterson ◽  
H. Katznelson
Keyword(s):  
Soil Microorganisms ◽  
Rhizosphere Soil ◽  
Red Clover ◽  
Root Surface ◽  
Plant Roots ◽  
Favorable Effect ◽  
Bacterial Isolates ◽  
Rhizosphere Effect ◽  
Root Extracts ◽  
Wheat Rhizosphere

A study was made of the occurrence of nematode-trapping fungi in the rhizosphere and on the root surface of different plants. Arthrobotrys oligospora was the predominant predaceous fungus isolated. It was almost completely absent from plant roots but occurred in varying frequency in rhizosphere soil and in root-free soil. The incidence of this fungus was consistently greater in the soybean rhizosphere and lower in the wheat rhizosphere than in corresponding soil devoid of roots, whereas for other plants, red clover, flax, etc., there was no obvious rhizosphere effect. Spore germination tests and growth of A. oligospora in root extracts of soybeans and wheat failed to account for the differences observed. However, bacterial isolates from the wheat rhizosphere were, on the whole, more antagonistic to this fungus than those from the soybean rhizosphere, whereas isolates from the latter appeared to exert a favorable effect.

OBSERVATIONS ON FUNGI ASSOCIATED WITH PLANT ROOTS

1958 ◽  
Vol 4 (3) ◽  
pp. 257-265 ◽  
Author(s):  
E. A. Peterson
Keyword(s):  
Soil Type ◽  
Rhizosphere Soil ◽  
Red Clover ◽  
Root Surface ◽  
Plant Age ◽  
Seedling Stage ◽  
Plant Roots ◽  
Dilution Technique ◽  
Fungal Flora ◽  
Stages Of Growth

Plant age and soil type influence the nature of the fungal flora associated with plant roots. Total numbers of fungi in the rhizosphere of wheat, as determined by the dilution technique, increased with plant age but the degree of fungal stimulation appeared to depend upon soil type. Penicillia and certain species of the Mucorales were relatively more abundant on the root surface and in the rhizosphere at the seedling stage than at later stages of growth. Species of Fusarium and/or Cylindrocarpon (depending upon soil type) and various sterile dark fungi were predominant on the roots of healthy red clover and wheat, but were relatively rare in rhizosphere and non-rhizosphere soil.

STUDIES ON THE RELATIONSHIPS BETWEEN NEMATODES AND OTHER SOIL MICROORGANISMS: II. INTERACTIONS OF APHELENCHOIDES PARIETINUS (BASTIAN, 1865) STEINER 1932 WITH ACTINOMYCETES, BACTERIA, AND FUNGI

1964 ◽  
Vol 10 (1) ◽  
pp. 37-41 ◽  
Author(s):  
H. Katznelson ◽  
V. E. Henderson
Keyword(s):  
Soil Microorganisms ◽  
Rhizosphere Soil ◽  
Marked Effect ◽  
Root Zone ◽  
Bacterial Isolates ◽  
Bacterial Cultures ◽  
Bacteria And Fungi

The influence of actinomycetes, bacteria, and fungi on Aphelenchoides parietinus (Bastian, 1865) Steiner, 1932, a fungus-feeding nematode, was studied. Thirty percent of the actinomycete cultures tested showed some "attraction" for this nematode on agar plates. The filtrates from a number of these actinomycete cultures favored accumulation of nematodes on areas of agar on which the fluids were spotted. In some instances the nematodes were repelled from these areas. Of the 60 bacterial isolates from rhizosphere soil only one "attracted" the nematode; most of the others repelled it. The filtrates from most of these bacterial cultures were similarly unfavorable. The nematode aggregated strongly around 43 of 54 cultures of fungi, and propagated on 32 of these. The results suggest that the microflora of the root zone may exert a marked effect on the accumulation of this nematode therein.

scholarly journals Soil Rhizosphere Microbial Properties of Selected Farmlands in Rumuokparali Community

2018 ◽  
pp. 1-7
Author(s):  
H. O. Stanley ◽  
J. Alexander ◽  
C. J. Ugboma
Keyword(s):  
Soil Microorganisms ◽  
Rhizosphere Soil ◽  
Bacterial Count ◽  
Bulk Soil ◽  
Bacterial Isolates ◽  
Rhizosphere Microorganisms ◽  
Fungal Isolates ◽  
Soil Rhizosphere ◽  
Soil Bacterial ◽  
Talinum Triangulare

This study was conducted to determine the rhizosphere soil microorganisms associated with the cultivation of Manihot esculentum, Comelina bengalensis, Talinum triangulare and Telfairia occidentalis. The plants were obtained from newly cultivated, ready for harvest and fallowed farmlands. The rhizosphere microorganisms were enumerated and compared with bulk soil microorganisms. The heterotrophic bacterial count for newly cultivated farmland ranged from 2.9 x107-6.3x108 cfug-1 and total fungal ranged from 5.6 x104-7.0 x106 sfug-1, while the bulk soil total heterotrophic bacterial count was 4.96 x 109 cfug-1 and the total fungal count was 5.87 x 106 sfug-1. The heterotrophic bacterial count for ready for harvest farmland ranged from 1.82 x108-1.80 x109 cfug-1 and total fungal ranged from 2.3 x104-3.57x106 sfug-1, while the bulk soil total heterotrophic bacterial count was 1.90x109 cfug-1 and the total fungal count was 2.30x106 sfug-1. The heterotrophic bacterial count for fallowed farmland ranged from 5.65 x108-1.50x109 cfug-1 and total fungal ranged from 1.33 x106-3.05x106 sfug-1, while bulk soil total heterotrophic bacterial count was 1.74.0x109 cfug-1 and total fungal count was 1.07x106 sfug-1. The rhizosphere soil bacterial isolates belong to the genera: Staphylococcus, Hafnia,  Acinetobacter, Bacillus, Bacteroides, Klebsiella, Tatumella, Enterobacter, Corynebacterium and Pseudomonas while fungal isolates belong to the genera: Aspergillus, Epicocum, Chrysosporium, Trichosporon, Cryptococcus, Fusarium, Penicillium and Chaetomium.  The bulk soil bacterial isolates belong to genera: Staphylococcus, Hafnia, Acinetobacter, Bacillus, Klebsiella, Tatumella, Corynebacterium and Pseudomonas while the fungal isolates belong to genera: Aspergillus, Epicocum, Chrysosporium, Trichosporon, Cryptococcus and Chaetomium. Microbial diversity of rhizosphere soil was more compared to bulk soil.

scholarly journals A Cross-Metabolomic Approach Shows that Wheat Interferes with Fluorescent Pseudomonas Physiology through Its Root Metabolites

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 84
Author(s):  
Laura Rieusset ◽  
Marjolaine Rey ◽  
Florence Gerin ◽  
Florence Wisniewski-Dyé ◽  
Claire Prigent-Combaret ◽  
...  
Keyword(s):  
Secondary Metabolites ◽  
Host Plant ◽  
Soil Microorganisms ◽  
Wheat Root ◽  
Bioactive Metabolites ◽  
Root Extracts ◽  
Fluorescent Pseudomonas ◽  
Health And Development ◽  
The Impact ◽  
Metabolomic Approach

Roots contain a wide variety of secondary metabolites. Some of them are exudated in the rhizosphere, where they are able to attract and/or control a large diversity of microbial species. In return, the rhizomicrobiota can promote plant health and development. Some rhizobacteria belonging to the Pseudomonas genus are known to produce a wide diversity of secondary metabolites that can exert a biological activity on the host plant and on other soil microorganisms. Nevertheless, the impact of the host plant on the production of bioactive metabolites by Pseudomonas is still poorly understood. To characterize the impact of plants on the secondary metabolism of Pseudomonas, a cross-metabolomic approach has been developed. Five different fluorescent Pseudomonas strains were thus cultivated in the presence of a low concentration of wheat root extracts recovered from three wheat genotypes. Analysis of our metabolomic workflow revealed that the production of several Pseudomonas secondary metabolites was significantly modulated when bacteria were cultivated with root extracts, including metabolites involved in plant-beneficial properties.

scholarly journals Number of Microorganisms in the Soil Cultivated with Legume-Grass Mixtures Supplied with Phytohormones and Nitrogen

2014 ◽  
Vol 6 (4) ◽  
pp. 498-504
Author(s):  
Jacek SOSNOWSKI ◽  
Kazimierz JANKOWSKI ◽  
Roxana VIDICAN ◽  
Beata WIŚNIEWSKA-KADŻAJAN ◽  
Elżbieta MALINOWSKA ◽  
...  
Keyword(s):  
Soil Microorganisms ◽  
Soil Fungi ◽  
Red Clover ◽  
Soil Material ◽  
Humus Layer ◽  
Number Of Microorganisms ◽  
Four Levels ◽  
Intensive Development ◽  
Number Of Bacteria ◽  
Different Doses

The study concerned the number of microorganisms colonizing the humus layer and under plough soil from the cultivation of perennial ryegrass mixtures with red clover, which were fed by biostimulant based on the phytohormones  and different doses of nitrogen. Nitrogen was applied at four levels-control (no nitrogen), 50, 100 and 150 kg N∙ha-1, biostimulant in two combinations - with and without preparation. Soil material to assess the size of individual groups of microorganisms was collected from each experimental plot in autumn 2010 from the humus (0-20 cm) and under plough layers (20-40 cm). The analysis of soil samples for a total number of bacteria, actinomycetes and fungi was conducted at the Department of Agricultural Microbiology IUNG-PIB in Pulawy. Results of studies have shown that more colonies of bacteria, actinomycetes and fungi were colonized the humus horizon. Biostimulant application in this cultivation led to a decrease of the total number of colonies of the all soil microorganisms groups but improved the ratio of bacteria to fungi. Increasing doses of mineral nitrogen by the limiting of the bacteria number and intensive development of soil fungi, helped to narrow the B/F ratio.

scholarly journals OPTIMALISASI PRODUKSI ENZIM KITINASE PADA ISOLAT JAMUR KITINOLITIK DARI SAMPEL TANAH RIZOSFER

2018 ◽  
Vol 3 (01) ◽  
pp. 62-69
Author(s):  
Eka Corneliyawati ◽  
Massora Massora ◽  
Khikmah Khikmah ◽  
As’ad Syamsul Arifin
Keyword(s):  
Biological Control ◽  
Cell Wall ◽  
Rhizosphere Soil ◽  
Plant Root ◽  
Optimal Growth ◽  
Chitinase Activity ◽  
Fungal Species ◽  
Plant Roots ◽  
Chitinase Production

The rhizosphere is the zone of soil surrounding a plant root where plant roots, soil and the soil biota interact with each other. Chitinolytic fungi has been effectively used in biological control agens. The chitinase activity causes lysis of the fungi cell wall pathogen. The aim of the research was to find optimization of activity chitinase enzyme from rhizosphere soil was conducted in vitro. Optimal growth chitinase production for TKR3 fungi isolate were concentration of chitin 0,2% (b/v), pH 5,5, temperature 30ºC, agitation 150 rpm and incubation time at four days. The optimum yield of chitinase production is influenced by fungal species and environmental conditions.

scholarly journals Bacterial Composition and Diversity Associated with Rhizosphere of the Chinese Medicinal Herb Dendrobium

2020 ◽  
Author(s):  
Yingdan Yuan ◽  
Mengting Zu ◽  
Lei Liu ◽  
Xiaomei Song
Keyword(s):  
Microbial Community ◽  
Environmental Factor ◽  
Bacterial Communities ◽  
Soil Microorganisms ◽  
Rhizosphere Soil ◽  
Available Phosphorus ◽  
Maturity Stage ◽  
Bacterial Phyla ◽  
Rhizosphere Microorganisms ◽  
Rhizosphere Microbial Community

Abstract Background: Dendrobium is a precious herbal belongs to Orchid and widely used as health care traditional Chinese medicine in Asia. Although orchids are mycorrhizal plants, most researches still focus on endophytes, and there is still large unknown in rhizosphere microorganisms. In order to investigate the rhizosphere microbial community of different Dendrobium species during the maturity stage, we used high-throughput sequencing to analyze microbial community in rhizosphere soil during maturity stage of three kinds of Dendrobium species.Results: In our study, a total of 240,320 sequences and 11,179 OTUs were obtained from these three Dendrobium species. According to the analysis of OTU annotation results, different Dendrobium rhizosphere soil bacteria include 2 kingdoms, 63 phyla, 72 classes, 159 orders, 309 families, 850 genera and 663 species. Among all sequences, the dominant bacterial phyla (relative abundance > 1%) were Proteobacteria, Actinobacteria, Bacteroidetes, Acidobacteria, Firmicutes, Verrucomicrobia, Planctomycetes, Chloroflexi, Gemmatimonadetes. We analyzed the environmental factors of the growth of Dendrobium and found that the environmental factor that affects the rhizosphere soil microorganisms of Dendrobium is the soil factor. Among them, soil factors most closely related to the influence of Dendrobium rhizosphere soil microorganisms include total nitrogen, available phosphorus, ammonium nitrogen and pH value.Conclusions: We found that the rhizosphere bacterial communities of the three kinds of Dendrobium have significant differences, and the main species of rhizosphere microorganisms of Dendrobium are concentrated in the Proteobacteria, Actinobacteria, Bacteroidetes. Moreover, the smaller the level of bacterial, the greater the difference among Dendrobium species. Soil is the most important environmental factor affecting the bacterial communities in the rhizosphere soil of Dendrobium. These results fill the gap in the rhizosphere microbial community of Dendrobium and provide a theoretical basis for the subsequent mining of microbial functions and the study of biological fertilizers.

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