Populations of the spinach wilt pathogen, Fusarium oxysporum f. sp. spinaciae, in the root tissues, rhizosphere, and soil in the field

1979 ◽  
Vol 25 (2) ◽  
pp. 227-229 ◽  
Author(s):  
Andres A. Reyes
Keyword(s):  
Fusarium Oxysporum ◽  
Chinese Cabbage ◽  
Rhizosphere Soil ◽  
Infested Field ◽  
Soil Rhizosphere ◽  
Root Tissues

Populations of Fusarium oxysporum f. sp. spinaciae in root tissues and rhizosphere soil of diseased spinach plants were higher than in the root tissues and rhizosphere soil of healthy plants. Populations in soil rhizosphere were higher than in nonrhizosphere soil. The fungus populations were very low in the root tissues of the nonsusceptible strawberry, broccoli, Chinese cabbage, and mustard grown in the infested field. The populations were low at the beginning of the season, increased, and remained high during the summer, then dropped in the fall. The fungus populations ranged from 1600 to 2600 propagules/g in the top 10 cm of soil, declined sharply between 11 and 20 cm, and were nondetectable between 41 and 60 cm.

Effects of Fusarium oxysporum f. sp. cubense race 4 on microorganisms and enzyme activities in the rhizosphere soil of banana

2013 ◽  
Vol 38 (2) ◽  
pp. 173-176 ◽  
Author(s):  
Yong-hong HUANG ◽  
Shun LÜ ◽  
Chun-yu LI ◽  
Yue-rong WEI ◽  
Gan-jun YI
Keyword(s):  
Fusarium Oxysporum ◽  
Enzyme Activities ◽  
Rhizosphere Soil ◽  
Race 4

Divergent response of heavy metal bioavailability in soil rhizosphere to agricultural land use change from paddy field to various drylands

2021 ◽  
Author(s):  
Yujuan Gao ◽  
Jianli Jia ◽  
Beidou Xi ◽  
Dongyu Cui ◽  
Wenbing Tan
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Land Use ◽  
Land Use Change ◽  
Agricultural Land ◽  
Rhizosphere Soil ◽  
Agricultural Land Use ◽  
Metal Bioavailability ◽  
Soil Rhizosphere ◽  
Divergent Response

The heavy metal pollution induced by agricultural land use change has attracted great attention. In this study, the divergent response of bioavailability of heavy metals in rhizosphere soil to different...

POPULATIONS OF FUSARIUM OXYSPORUM F. MELONIS AND THEIR RELATION TO THE WILT POTENTIAL OF TWO SOILS

1963 ◽  
Vol 9 (2) ◽  
pp. 237-249 ◽  
Author(s):  
R. N. Wensley ◽  
C. D. McKeen
Keyword(s):  
Fusarium Oxysporum ◽  
Random Sampling ◽  
Direct Relationship ◽  
Sandy Loam ◽  
Sandy Loam Soil ◽  
Random Samples ◽  
Field Soils ◽  
Infested Field ◽  
Loam Soil ◽  
Wilt Incidence

The relation of soil populations of the muskmelon wilt fungus, Fusarium oxysporum f. melonis, to the wilt potentials of a yellow Fox sandy loam soil (Fsl) and a dark Colwood loam (Cl) was investigated. In either soil a direct relationship existed between the size of the population of the fungus and wilt incidence. Notwithstanding this relationship, with the same population the greater incidence of wilt in Fsl than in Cl showed that a factor or factors other than population affect the wilt potential. Whereas mean populations of field soils obtained at the site of wilted plants ranged upward to 3300 per gram, they declined steadily during the 9-month interval between crops. During this interval random samples of field soils yielded mean populations of 228 and 268 per gram of Fsl and Cl, respectively. Of the F. oxysporum colonies isolated at the end of harvest, about 70% from plant sites and approximately 21% from intersites were pathogenic. Two to eight months later only 12 to 15% of F. oxysporum isolates obtained by random sampling of infested field soils were pathogenic.

scholarly journals Treatment with the Mycoparasite Pythium oligandrum Triggers Induction of Defense-Related Reactions in Tomato Roots When Challenged with Fusarium oxysporum f. sp. radicis-lycopersici

1997 ◽  
Vol 87 (1) ◽  
pp. 108-122 ◽  
Author(s):  
Nicole Benhamou ◽  
Patrice Rey ◽  
Mohamed Chérif ◽  
John Hockenhull ◽  
Yves Tirilly
Keyword(s):  
Plant Defense ◽  
Fusarium Oxysporum ◽  
Host Cell ◽  
Cell Walls ◽  
Pythium Oligandrum ◽  
Tomato Plants ◽  
Host Cytoplasm ◽  
Defense Reactions ◽  
Tomato Roots ◽  
Root Tissues

The influence exerted by the mycoparasite Pythium oligandrum in triggering plant defense reactions was investigated using an experimental system in which tomato plants were infected with the crown and root rot pathogen Fusarium oxysporum f. sp. radicis-lycopersici. To assess the antagonistic potential of P. oligandrum against F. oxysporum f. sp. radicis-lycopersici, the interaction between the two fungi was studied by scanning and transmission electron microscopy (SEM and TEM, respectively). SEM investigations of the interaction region between the fungi demonstrated that collapse and loss of turgor of F. oxysporum f. sp. radicis-lycopersici hyphae began soon after close contact was established with P. oligandrum. Ultrastructural observations confirmed that intimate contact between hyphae of P. oligandrum and cells of the pathogen resulted in a series of disturbances, including generalized disorganization of the host cytoplasm, retraction of the plasmalemma, and, finally, complete loss of the protoplasm. Cytochemical labeling of chitin with wheat germ agglutinin (WGA)/ovomucoid-gold complex showed that, except in the area of hyphal penetration, the chitin component of the host cell walls was structurally preserved at a time when the host cytoplasm had undergone complete disorganization. Interestingly, the same antagonistic process was observed in planta. The specific labeling patterns obtained with the exoglucanase-gold and WGA-ovomucoid-gold complexes confirmed that P. oligandrum successfully penetrated invading cells of the pathogen without causing substantial cell wall alterations, shown by the intense labeling of chitin. Cytological investigations of samples from P. oligandrum-inoculated tomato roots revealed that the fungus was able to colonize root tissues without inducing extensive cell damage. However, there was a novel finding concerning the structural alteration of the invading hyphae, evidenced by the frequent occurrence of empty fungal shells in root tissues. Pythium ingress in root tissues was associated with host metabolic changes, culminating in the elaboration of structural barriers at sites of potential fungal penetration. Striking differences in the extent of F. oxysporum f. sp. radicis-lycopersici colonization were observed between P. oligandrum-inoculated and control tomato plants. In control roots, the pathogen multiplied abundantly through much of the tissues, whereas in P. oligandrum-colonized roots pathogen growth was restricted to the outermost root tissues. This restricted pattern of pathogen colonization was accompanied by deposition of newly formed barriers beyond the infection sites. These host reactions appeared to be amplified compared to those seen in nonchallenged P. oligandrum-infected plants. Most hyphae of the pathogen that penetrated the epidermis exhibited considerable changes. Wall appositions contained large amounts of callose, in addition to be infiltrated with phenolic compounds. The labeling pattern obtained with gold-complexed laccase showed that phenolics were widely distributed in Fusarium-challenged P. oligandrum-inoculated tomato roots. Such compounds accumulated in the host cell walls and intercellular spaces. The wall-bound chitin component in Fusarium hyphae colonizing P. oligandrum-inoculated roots was preserved at a time when hyphae had undergone substantial degradation. These observations provide the first convincing evidence that P. oligandrum has the potential to induce plant defense reactions in addition to acting as a mycoparasite.

scholarly journals Digitaria insularis Management and Nematode Dynamics in Off-season Maize

2020 ◽  
Vol 8 (2) ◽  
pp. 729
Author(s):  
Marcos Massuo Kashiwaqui ◽  
Claudia Regina Dias-Arieira ◽  
João Paulo Matias ◽  
André A. Pazinato da Silva ◽  
José Cristimiano dos Santos Neto ◽  
...  
Keyword(s):  
Weed Management ◽  
Management System ◽  
Rhizosphere Soil ◽  
Control Level ◽  
Management Systems ◽  
Acetyl Coa Carboxylase ◽  
Continuous Increase ◽  
Maize Roots ◽  
Excellent Control ◽  
Soil Rhizosphere

Maize stands out as one of the most important crops in succession to soybean in tropic countries. However, the susceptibility of both crops to nematodes, can cause a continuous increase in the nematode population, especially in areas where there is the occurrence of weeds susceptible to the parasites. Thus, the objective was to evaluate the nematodes dynamics in a growing area with off-season maize under chemical weed management. The experiment was installed at Tuneiras do Oeste County, Brazil, designed in randomized blocks, with seven treatments and five replications, constituted by sourgrass (Digitaria insularis) management systems with glyphosate associated to herbicides inhibitors of the enzyme acetyl-CoA carboxylase (ACCase) and auxin-mimetic, and complement with glyphosate + atrazine + tembotrione in post-emergence. The effect of treatments on Pratylenchus spp. population was observed in roots and soil rhizosphere soil of D. insularis and in maize roots. Glyphosate application followed by glyphosate + atrazine was inefficient in controlling sourgrass. Management system with glyphosate + clethodim + 2.4-D followed by glyphosate + atrazine + tembotrione reduced the Pratylenchus spp. population in sourgrass, but any management system repeated this effect in maize. Management systems of D. insularis with associations of glyphosate + clethodim; glyphosate + clethodim + 2.4-D and glyphosate + fenoxaprop-p-ethyl, all followed by glyphosate + atrazine + tembotrione, showed excellent control level of sourgrass without affecting plant height, grain and rank numbers and grain yield. It is concluded that the management system using herbicides association controlled sourgrass and may interferer on Pratylenchus spp. population.

Occurrence of Fusarium spp. associated with root tissues and rhizosphere soils of forest trees and assessment of their pathogenicity on Prunus amygdalus seedlings

2010 ◽  
Vol 58 (8) ◽  
pp. 679 ◽  
Author(s):  
K. Chehri ◽  
B. Salleh ◽  
M. J. Soleimani ◽  
K. R. N. Reddy ◽  
L. Zakaria
Keyword(s):  
Rhizosphere Soil ◽  
Morphological Characteristics ◽  
Soil Samples ◽  
Forest Trees ◽  
Prunus Amygdalus ◽  
Fusarium Spp ◽  
The West ◽  
Rhizosphere Soils ◽  
Climatic Regions ◽  
Root Tissues

Occurrence, distribution and pathogenicity of Fusarium spp. associated with roots and rhizosphere soils of forest trees were studied. Fusarium spp. was isolated from phloem and sapwood of forest trees and composite rhizosphere soil samples collected from highly diversified geographical and climatic regions of the west of Iran and identified based on their morphological characteristics. Only three Fusarium spp. (F. oxysporum, F. solani and F. eumartii) was isolated from roots. F. nygamai, F. graminearum, F. scirpi, F. proliferatum, F. anthophilum, F. longipes and F. chlamydosporum were recovered from soil samples collected from warm and moderately warm regions, while F. culmorum, F. sporotrichioides, F. sambucinum and F. subglutinans were recovered from cold regions. F. solani, F. oxysporum, F. semitectum, F. equiseti, F. verticillioides, F. merismoides and F. avenaceum were present in all climatic regions. In the bark inoculation tests, selected Fusarium strains representing all species were evaluated for their pathogenicity on stems of healthy Prunus amygdalus under greenhouse conditions. Stem rot assessment revealed that F. oxysporum, F. solani and F. eumartii were the most damaging species.

scholarly journals Effect of Some Environmental Factors on the Growth of Azospirillum Species Isolated from Saline Soils of Satkhira District, Bangladesh

1970 ◽  
Vol 23 (2) ◽  
pp. 145-148 ◽  
Author(s):  
M Motiur Rahman ◽  
S Mubassara ◽  
Sirajul Hoque ◽  
Zahed UM Khan
Keyword(s):  
Rhizosphere Soil ◽  
Cynodon Dactylon ◽  
Optimal Growth ◽  
Maximum Growth ◽  
Alkaline Condition ◽  
Saline Soils ◽  
Azospirillum Lipoferum ◽  
Nacl Concentration ◽  
Saline Area ◽  
Soil Rhizosphere

Twelve isolates of Azospirillum, recovered and identified from non-rhizosphere soil, rhizosphere soil of Cynodon dactylon and the roots of the same plant, were collected from five different locations of saline area in the district Satkhira, Bangladesh. The isolates were belonged to Azospirillum lipoferum, A. brasilense, A. halopraeferans and A. amazonense. All isolates, except MR-5, preferred neutral to alkaline condition for their optimal growth. Three isolates (MR-3, MR-4 and MR-8) showed maximum growth at 41°C, while the others grew best at temperature between 35° and 37°C. The optimal NaCl concentration for the growth was found to be 3% for 5 isolates (MR-1, MR-3, MR-4, MR-8 and MR-11) and 5% for the rest 7 isolates (MR-5, MR-6, MR-7, MR-13, MR-14, MR-15 and MR-16). All isolates were true halophilic since they did not show grow in absence of salinity, and all of them were also fungicide (Perfeckthion and Indofil M-45) tolerants to some extent. Keywords: Azospirillum, Growth characteristics, Halophilic, Tolerance to fungicideDOI: http://dx.doi.org/10.3329/bjm.v23i2.881 Bangladesh J Microbiol, Volume 23, Number 2, December 2006, pp 145-148

Recovery of a rhizosphere-colonizing GEM from inside wheat roots

1999 ◽  
Vol 45 (7) ◽  
pp. 612-615 ◽  
Author(s):  
James D Nairn ◽  
Christopher P Chanway
Keyword(s):  
Rhizosphere Soil ◽  
Genetically Engineered ◽  
Root Tissue ◽  
Marker Genes ◽  
Wheat Roots ◽  
Genetically Engineered Microorganisms ◽  
Population Sizes ◽  
Genetically Engineered Microorganism ◽  
Root Tissues ◽  
Fresh Root

Pseudomonas chloroaphis 3732 RN-L11 is a genetically modified bacterial strain that contains the lacZY marker genes in its chromosome. This strain is known to be a vigorous colonizer of plant roots and rhizosphere soil, and has been used as a model to evaluate survival and persistence of field-released genetically engineered microorganisms (GEMs). However, the possibility that strain 3732 RN-L11 may also colonize internal plant tissues has not previously been investigated. Using spring wheat as a model system, we studied the ability of strain 3732 RN-L11 to colonize external and internal root tissues after seed inoculation. Strain 3732 RN-L11 was recovered from rhizosphere soil of 28-, 42-, and 56-day-old seedlings with mean population sizes of 3.3 × 105, 7.5 × 104, and 2.2 × 105CFU·g-1fresh root tissue, respectively. In addition, this strain was consistently recovered from surface-sterilized root tissues of 28- to 56-day-old seedlings with mean population sizes of 1.0 × 102to 6.2 × 103CFU·g-1fresh root tissue. Our results indicate that evaluation of plant-associated GEM populations after field release should include all possible colonization niches, including internal plant tissues.Key words: genetically engineered microorganism, rhizosphere, endophyte.

Soil Microbial Functional Diversity from Different Infection Grades of Banana Fusarium Wilt (Fusarium oxysporum f. sp. Cubense)

2013 ◽  
Vol 295-298 ◽  
pp. 2274-2280 ◽  
Author(s):  
Xiao Deng ◽  
Qin Fen Li ◽  
Xian Wen Hou ◽  
Chun Yuan Wu
Keyword(s):  
Microbial Community ◽  
Fusarium Oxysporum ◽  
Functional Diversity ◽  
Fusarium Wilt ◽  
Soil Microbial Community ◽  
Rhizosphere Soil ◽  
Principal Component ◽  
Soil Microbial ◽  
Metabolic Characteristics ◽  
Environmental Measures

Thirty rhizosphere and non-rhizosphere soil samples from different infection grades(0, I, III, V and VII) of three typical banana plots(Jianfeng, Shiyuetian, Chongpo) infected by banana fusarium wilt (Fusarium oxysporum f. sp. cubense) in Hainan province were collected to study the microbial community functional diversity applying Biolog-ECO microplates technology. The results are as follows: (1) Overall carbon source metabolic capacities of soil microbial community weaken with increasing of infection grades of banana fusarium wilt. (2) Richness indices, Simpson indices, Shannon indices and McIntosh indices of soil microbial community gradually decreased with increasing of infection grades of banana fusarium wilt. (3) Principal component analysis show that metabolic characteristics of soil microbial community significantly change between the healthy plants and diseased plants in the same banana plot. The results would provide information for explaining the pathogenesis of banana fusarium wilt and controlling its incidence by applying microbial ecology to regulate soil environmental measures.

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