EFFETS DU SUBSTRAT SUR LA PATHOGENECITE DE QUELQUES CHAMPIGNONS DU SOL A L’EGARD DE LA LUZERNE

1969 ◽  
Vol 49 (6) ◽  
pp. 737-742
Author(s):  
Claude Aubé
Keyword(s):  
Rhizoctonia Solani ◽  
Fusarium Oxysporum ◽  
Soil Fungi ◽  
Trichoderma Viride ◽  
Artificial Substrates ◽  
Natural Soil ◽  
Growth Substrate ◽  
White Sand ◽  
The Difference ◽  
Greenhouse Tests

Under the conditions of the present work with four soil fungi and four substrates, the reaction of alfalfa to Trichoderma viride Pers. ex Fries, Pythium debaryanum Hesse, Fusarium oxysporum Schlecht. var. rodelens (Wr.) Gordon, and Rhizoctonia solani Kühn in greenhouse tests was affected by the nature of the growth substrate. The above-mentioned fungi were more pathogenic in artificial substrates, such as the vermiculite-perlite and vermiculite-white sand mixtures, than in natural soil. The increase of pathogenicity in artificial substrates varied with the fungus. In natural soil, the temperature was consistently higher than in artificial media which might account for the difference in pathogenicity of the fungi in the different substrates.

GROWTH INHIBITION OF TWO SAPROPHYTIC AND TWO PLANT PARASITIC SOIL FUNGI BY ANTIBIOTICS

1961 ◽  
Vol 39 (3) ◽  
pp. 491-495
Author(s):  
E. W. B. Ward ◽  
A. W. Henry
Keyword(s):  
Growth Inhibition ◽  
Soil Fungi ◽  
Agar Medium ◽  
Trichoderma Viride ◽  
Natural Soil ◽  
Plant Parasitic

Comparisons were made of growth inhibition of two saprophytic (Trichoderma viride, Trichocladium asperum) and two plant parasitic soil fungi (Ophiobolus graminis, Fomes annosus) by antibiotics. The fungi were grown on an agar medium containing various concentrations of one of the antibiotics: acti-dione, gliotoxin, griseofulvin, patulin, or trichothecin. In general the two parasites tended to be more sensitive than the saprophytes, but there were several individual exceptions. Moreover, the comparative responses of the fungi at different antibiotic concentrations were frequently not proportionately related. The results are discussed in relation to the possible effects of antibiotics on fungi in natural soil.

Effect of Dinitroanilines on Solanaceous Vegetables and Soil Fungi

Weed Science ◽  
1972 ◽  
Vol 20 (3) ◽  
pp. 243-246 ◽  
Author(s):  
Y. Eshel ◽  
J. Katan
Keyword(s):  
Lycopersicon Esculentum ◽  
Rhizoctonia Solani ◽  
Fusarium Oxysporum ◽  
Root Elongation ◽  
Soil Fungi ◽  
Pathogenic Fungi ◽  
Crop Tolerance ◽  
Low Toxicity ◽  
Black Beauty ◽  
Sensitive Fungus

The phytotoxicities of four substituted dinitroanilines,N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine (benefin), 2,6-dinitro-N,N-dipropylcumidine (isopropalin), 4-(methylsulfonyl)-2,6-dinitro-N,N-dipropylaniline (nitralin), and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine (trifluralin), to eggplant(Solarium melongenaL. ‘Black Beauty’), pepper(Capsicum annuumL. ‘Vindale’), and tomato(Lycopersicon esculentumMill. ‘VF 145-B-7879′) were studied. Nitralin and trifluralin were most active in inhibiting root elongation and top growth of these plants, the effect of benefin was intermediate, and isopropalin was the least active herbicide. The order of crop tolerance was as follows: tomato > pepper > eggplant. The effect of these herbicides on two pathogenic fungi,Rhizoctonia solaniKuehn andFusarium oxysporumf. sp.lycopersici(Sacc.) Snyd. and Hans. was tested in culture and was found to be quantitatively and qualitatively different from that on plants. With both fungi benefin and trifluralin were more toxic than isopropalin, while nitralin showed a very low toxicity.R. solaniwas the less sensitive fungus.

Hyphal interactions between a mycoparasite, Pythium nunn, and several soil fungi

1984 ◽  
Vol 30 (12) ◽  
pp. 1482-1487 ◽  
Author(s):  
R. Lifshitz ◽  
M. Dupler ◽  
Y. Elad ◽  
R. Baker
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Rhizoctonia Solani ◽  
Fusarium Oxysporum ◽  
Host Range ◽  
Phase Contrast ◽  
Soil Fungi ◽  
Limited Host Range ◽  
Pythium Nunn ◽  
Scanning Electron

The modes of hyphal interaction between a mycoparasite, Pythium nunn, and several soil fungi were studied by both phase-contrast and scanning-electron microscopy. In the zone of interaction, Pyth. nunn massively coiled around and subsequently lysed hyphae of Pyth. ultimum and Pyth. vexans. In contrast, Pyth. nunn penetrated and eventually parasitized hyphae of Rhizoctonia solani, Pyth. aphanidermatum, Phytophthora parasitica, and Phyto. cinnamomi by forming appressoriumlike structures. However, Pyth. nunn was not mycoparasitic against Fusarium oxysporum f.sp. cucumerinum or Trichoderma koningnii and was destroyed by T. harzianum and T. viride. These observations demonstrated that Pyth. nunn was a necrotrophic mycoparasite, with a limited host range and differential modes of action among suscepts.

scholarly journals INFLUENCE OF CERTAIN SOIL FUNGI ON ALFALFA

1970 ◽  
Vol 50 (2) ◽  
pp. 159-162 ◽  
Author(s):  
CLAUDE AUBE ◽  
CAMILIEN GAGNON
Keyword(s):  
Rhizoctonia Solani ◽  
Nitrogen Content ◽  
Soil Fungi ◽  
Trichoderma Viride ◽  
Dry Weight ◽  
Gliocladium Roseum ◽  
Pyrenochaeta Terrestris

Under the conditions of the present work with fungi isolated from the rhizosphere of diseased alfalfa roots, Gliocladium roseum (Link) Bainier and Trichoderma viride Pers. ex Fries were pathogenic to alfalfa seedlings. They stimulated the pathogenicity of Pyrenochaeta terrestris (Hans.) Gorenz, J. C. Walker and Larson and Rhizoctonia solani Kühn as measured by the dry weight of roots. Both T. viride and G. roseum significantly lowered the nitrogen content in shoots when inoculated alone, but the reverse was observed in the roots.

scholarly journals Calcium Biogeochemical Cycle in a Typical Karst Forest: Evidence from Calcium Isotope Compositions

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 666
Author(s):  
Guilin Han ◽  
Anton Eisenhauer ◽  
Jie Zeng ◽  
Man Liu
Keyword(s):  
Soil Depth ◽  
Isotope Composition ◽  
Soil Surface ◽  
Natural Soil ◽  
Calcium Isotope ◽  
Karst Forest ◽  
Content Ratio ◽  
The Difference ◽  
Preferential Uptake ◽  
Vital Factor

In order to better constrain calcium cycling in natural soil and in soil used for agriculture, we present the δ44/40Ca values measured in rainwater, groundwater, plants, soil, and bedrock samples from a representative karst forest in SW China. The δ44/40Ca values are found to differ by ≈3.0‰ in the karst forest ecosystem. The Ca isotope compositions and Ca contents of groundwater, rainwater, and bedrock suggest that the Ca of groundwater primarily originates from rainwater and bedrock. The δ44/40Ca values of plants are lower than that of soils, indicating the preferential uptake of light Ca isotopes by plants. The distribution of δ44/40Ca values in the soil profiles (increasing with soil depth) suggests that the recycling of crop-litter abundant with lighter Ca isotope has potential effects on soil Ca isotope composition. The soil Mg/Ca content ratio probably reflects the preferential plant uptake of Ca over Mg and the difference in soil maturity. Light Ca isotopes are more abundant in mature soils than nutrient-depleted soils. The relative abundance in the light Ca isotope (40Ca) is in the following order: farmland > burnt grassland > forests > grassland > shrubland. Our results further indicate that biological fractionation in a soil–plant system is a vital factor for Ca–geochemical transformations in soil surface systems.

Effect of particle size and delignification on the rate of digestion of hemicellulose and cellulose by cellulase in mature pangola grass stems

1983 ◽  
Vol 34 (3) ◽  
pp. 241 ◽  
Author(s):  
CW Ford
Keyword(s):  
Particle Size ◽  
Cell Walls ◽  
Trichoderma Viride ◽  
Structural Features ◽  
Cell Wall Polysaccharides ◽  
Particle Size Reduction ◽  
Digitaria Decumbens ◽  
Hemicellulose Degradation ◽  
Before And After ◽  
The Difference

Stem cell walls of pangola grass (Digitaria decumbens) were ground to two particle sizes (c. 1 and 0.1 mm diameter), and incubated with cellulase (ex. Trichoderma viride) for varying times before and after delignification. Total cell walls finely ground (0.1 mm) with a Spex Shatterbox mill were initially degraded more rapidly (to 24 h) than delignified 1 mm particles. Thereafter the delignified material was solubilized to a greater extent. Subsequent specific determinations of cell wall polysaccharides indicated that delignification increased the rate of hemicellulose degradation to a greater extent than did particle size reduction, whereas the opposite was found for cellulose. The difference between delignified and Spex-ground residues, in terms of the amount of polysaccharide digested, was much greater for cellulose than hemicellulose. It is concluded that structural features play a more important role in limiting cellulase degradation of cellulose than does association with lignin, the reverse being so for hemicellulose.

scholarly journals Host And Temperature Preferensce, Male Occurrence And Morfomentrics Offungivorous Nematode, Aphelenchus Avenae Isolates From Japan

2016 ◽  
Vol 7 (1) ◽  
pp. 39-48
Author(s):  
Buni Amin
Keyword(s):  
Rhizoctonia Solani ◽  
Fusarium Oxysporum ◽  
Botrytis Cinerea ◽  
Significant Variation ◽  
Host Preference ◽  
Temperature Preference ◽  
Body Dimension ◽  
Temperature Regimes ◽  
Aphelenchus Avenae

ABSTRACT. Host and temperature preference, male accurrence, and morfomentrics of 39 isolates of Apehelenchus avenae were investigated. Of the 39 isolates, 33 were from 7 sistrict of Kyushu, 3 preference were investigated on 4 species of fungi; Botrytis cinerea, Rhizoctonia solani AG-4, Fusarium oxysporum f. sp. Melonis, and Pyitum aphanidermatum growing on 1/5 strength PDA medium. The nematodes were incubated on respective fungus mat for 30 days at 25 and 30 OC host fungi and temperatures gave rise to various levels of reproduction and male accurance. The isolates were divided into 5 groups based on their reproductivity on their host fungi at the 2 temperature regimes. Most of the isolates of A. avenae progated themselves at 25 0C on B. cinera and R. solani AG-4, was 60.850 given by Nagasaki isolates (NA3). The maximum multiplication 48.420 at 0C accured on R. solani byu Kagoshima isiolate (KA3). The occurrence of males was very low in all isolates and it occurred only at 30 0C. De Man’s value of body dimension were measured and showed no significant variation among the isolates. Besides, There were no realtions between groupings by host preference and by body dimension.

scholarly journals Desinfestação de substratos para produção de mudas, utilizando vapor de água

2001 ◽  
Vol 19 (2) ◽  
pp. 155-158
Author(s):  
João Bosco C. Silva ◽  
Ivani T. Oliveira-Napoleão ◽  
Loeni L. Falcão
Keyword(s):  
Rhizoctonia Solani ◽  
Fusarium Oxysporum ◽  
Sclerotinia Sclerotiorum ◽  
Ralstonia Solanacearum

O tratamento sanitário de substratos é uma operação importante no processo de produção de mudas e no cultivo de plantas em vasos ou outros contentores. Tradicionalmente tem-se utilizado o gás brometo de metila como agente desinfetante. Entretanto, a produção deste gás deverá ser abolida até o ano 2010, forçando-se a busca de novas opções. Desenvolveu-se na Embrapa Hortaliças um equipamento que utiliza o vapor de água à baixa pressão, produzido por uma caldeira industrial, com capacidade para evaporar 30 L/h de água, para aquecer o substrato contido em uma caixa metálica cilíndrica com capacidade de 2000 L. O vapor é aplicado no fundo da caixa que contém uma camada de brita coberta com uma tela metálica de malha de 2 mm, que favorece a distribuição uniforme do vapor por toda a massa de substrato. O tempo de aquecimento é de aproximadamente 3 horas e o calor armazenado durante este período mantém a massa de substrato aquecida a temperaturas pasteurizantes, por até 4 horas após a aplicação do vapor. Para testar a eficácia do sistema avaliou-se a sobrevivência dos patógenos Ralstonia solanacearum, Fusarium oxysporum, Sclerotinia sclerotiorum e Rhizoctonia solani. Aplicou-se vapor por uma hora, não considerando o período de aquecimento, e coletaram-se as amostras após uma, duas, três ou quatro horas o início da aplicação de vapor. O tratamento por uma hora, em adição ao período de aquecimento, resultou na eliminação dos patógenos.

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