Fusarium oxysporum (Schlecht.) Snyd. et Hans. — A dominant fungus species on the root-surface of woody plant seedlings

1968 ◽  
Vol 28 (2) ◽  
pp. 306-312
Author(s):  
Jarmila Kubíková
2014 ◽  
Vol 14 (2) ◽  
pp. 142-151
Author(s):  
I Ketut Suada ◽  
Ni Wayan Suniti

Isolation and identification of mangosteen yellow latex pathogen through Koch’s Postulate application and molecular analysis. The yellow latex disease decreases fruit quality of mangosteen because exogenic latex causes dirty fruit and the endogenic latex makes the bitter fruit taste and does not deserve to be consumed. The causal agent of the disease caused phusilogical disorder so that cells break due to unstability of cell turgor, the drift irrigation treatment was able to decrease the disease of 35.22%, therefore the causal agent could be microbe that promote the yellow latex. This research was aimed to find the yellow latex pathogens with its characteristics. The Koch Postulate was apllied to isolate and proved the microbes associated to the yellow latex and molecular analysis was constructed subsequently to find the microbe species.  The result of the research proved that there were three fungus species as the biotic agent responsible to the disease. The fungus were Verticillium albo-atrum with the highest pathogenecity ( 74.87%), followed by Fusarium oxysporum ( 70.15%), and Pestalotia macrotricha (20.32%).


2002 ◽  
Vol 38 (SI 1 - 6th Conf EFPP 2002) ◽  
pp. 195-199 ◽  
Author(s):  
C. Alabouvette ◽  
Ch. Olivain

Many studies have demonstrated the capacity of non-pathogenic strains of F. oxysporum to control Fusarium diseases.<br />These non-pathogenic strains show several modes of action contributing to their biocontrol capacity. They are able to<br />compete for nutrients in the soil, affecting the rate of chlamydospore germination and the saprophytic growth of the<br />pathogen, diminishing the probability for the pathogen to reach the root surface. They are competing with the pathogen<br />at the root surface for colonization of infection sites, and inside the root where they induce plant defence reactions. By<br />triggering the defence reactions, they induce systemic resistance of the plant. Depending on the strain, and on the plant<br />species, these mechanisms are more or less important, leading to a more or less efficient biocontrol efficacy.


2001 ◽  
Vol 91 (5) ◽  
pp. 449-456 ◽  
Author(s):  
Jian R. Bao ◽  
George Lazarovits

Histochemical staining, β-glucuronidase (GUS) activity, or placing roots on agar were methods used to characterize interactions between the pathogenic fungus, Fusarium oxysporum f. sp. lycopersici, and the nonpathogenic biocontrol F. oxysporum strain 70T01 with respect to colonization behaviors, interaction sites, and population densities on tomato roots. Mycelia of strain 70T01, a genetic transformant expressing stable GUS activity, hygromycin B resistance, and effective disease control, were localized in epidermal and cortex cell layers of tomato roots in a discontinuous and uneven pattern. In contrast, mycelia of F. oxysporum f. sp. lycopersici were found in the vascular bundles. Thus, direct interactions between the two fungi likely happen in the root surface cell layers. Colonization density of strain 70T01 was related to the inoculation density but decreased with distance from the inoculation site. Host defense reactions, including increased cell wall thickness or papilla deposits, were adjacent to 70T01 hyphae. Experiments done in soil showed that strain 70T01 densities in roots were highest at inoculation zones and barely detectable for root segments more than 2 cm away from the inoculation sites. F. oxysporum f. sp. lycopersici densities were lowest at 70T01 inoculation zones and highest (>10 times) where strain 70T01 was not directly applied. Newly elongating roots where strain 70T01 did not reach were available for infection by the pathogen. The higher strain 70T01 density was always found when the plants were simultaneously infected by F. oxysporum f. sp. lycopersici, suggesting that F. oxysporum f. sp. lycopersici has as much influence in predisposing the plant to colonization by strain 70T01 as strain 70T01 has on providing disease protection against the pathogen.


2006 ◽  
Vol 72 (2) ◽  
pp. 1523-1531 ◽  
Author(s):  
Chantal Olivain ◽  
Claude Humbert ◽  
Jarmila Nahalkova ◽  
Jamshid Fatehi ◽  
Floriane L'Haridon ◽  
...  

ABSTRACT In soil, fungal colonization of plant roots has been traditionally studied by indirect methods such as microbial isolation that do not enable direct observation of infection sites or of interactions between fungal pathogens and their antagonists. Confocal laser scanning microscopy was used to visualize the colonization of tomato roots in heat-treated soil and to observe the interactions between a nonpathogenic strain, Fo47, and a pathogenic strain, Fol8, inoculated onto tomato roots in soil. When inoculated separately, both fungi colonized the entire root surface, with the exception of the apical zone. When both strains were introduced together, they both colonized the root surface and were observed at the same locations. When Fo47 was introduced at a higher concentration than Fol8, it colonized much of the root surface, but hyphae of Fol8 could still be observed at the same location on the root. There was no exclusion of the pathogenic strain by the presence of the nonpathogenic strain. These results are not consistent with the hypothesis that specific infection sites exist on the root for Fusarium oxysporum and instead support the hypothesis that competition occurs for nutrients rather than for infection sites.


2006 ◽  
Vol 20 (4) ◽  
pp. 971-979 ◽  
Author(s):  
Mitchell P. Blair ◽  
Shepard M. Zedaker ◽  
John R. Seiler ◽  
Perry L. Hipkins ◽  
Patrick L. Burch

Woody plant herbicide screening techniques were evaluated to expedite the screening process and decrease amounts of herbicide active ingredient required. Rapid greenhouse screening of woody plant seedlings was performed in less than 6 months, and rapid seed screening was performed in less than 20 days. A traditional field screen, requiring 10 months from application to final evaluation, was performed for comparison and regression modeling purposes. Imazapyr and triclopyr were used as test chemicals and linear regressions were generated to predict traditional field screen results from rapid screens. Significant regressions were produced that predicted field responses of loblolly pine, sweetgum, and yellow-poplar with the use of both herbicides and either rapid screening technique. This indicated that rapid screening techniques could determine herbicide efficacy and/or species spectrum in much less time with significantly less herbicide. Rapid greenhouse screens of triclopyr produced more statistically significant regressions than those using imazapyr. Rapid seed screens could estimate species spectrum within 5 days after treatment. These results indicate that rapid greenhouse screen and rapid seed screen techniques can provide woody plant herbicide developers initial efficacy and spectrum of control data in a cost- and-time effective manner.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Pramod Mahajan ◽  
S. K. Dhoke ◽  
A. S. Khanna

The present study demonstrates an effect of nano-ZnO particles on the growth of plant seedlings of mung (Vigna radiate) and gram (Cicer arietinum). The study was carried out in plant agar media to prevent precipitation of water-insoluble nanoparticles in the test units. Various concentrations of nano-ZnO particles in suspension form were introduced to the agar media, and their effect on the root and shoot growth of the seedlings was examined. The main experimental approach, using correlative light and scanning electron microscopy provided evidence of adsorption of nanoparticles on the root surface. Absorption of nanoparticles by seedlings root was also detected by inductive coupled plasma/atomic emission spectroscopy (ICP-AES). It was found that at certain optimum concentration, the seedlings displayed good growth over control, and beyond that, retardation in growth was observed.


1964 ◽  
Vol 10 (5) ◽  
pp. 727-737 ◽  
Author(s):  
J. L. Townshend

Aphelenchus avenae Bastian, 1865 and Bursaphelenchus fungivorus Franklin & Hooper, 1962 fed and reproduced on 54 and 56, respectively, of 59 fungus species. Both nematodes were attracted to most of the fungi, whether hosts or non-hosts. However, Sclerotium rolfsii Saccardo repulsed A. avenae, and Agaricus hortensis Cooke had no effect. Aphelenchus avenae was more strongly attracted to Fusarium oxysporum lycopersici (Saccardo) Snyder & Hansen than to the roots of seedlings.


Mangifera Edu ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 29-43
Author(s):  
Tri Handayani

ABSTRACT Woody  plant produce small to large seeds which can affect germination process. Cotyledons as an important food source for early growth of seedlings. The position, function, and type of cotyledons when seeds germinate varies. This research aimed to determine cotyledons characters of woody plant seedlings collection  in Bogor Botanic Gardens. The position, function and type  of cotyledons were observed for 65 species of seedlings.This research used an observative method and was analyzed descriptively.The position of cotyledons when the seeds germinate are epigeal (above the ground) and hypogeal (remain in the soil). The epigeal cotyledons type found in 44 species that is higher than hypogeal cotyledons type (21 species). The function of cotyledons for seedlings is to reserve food or photosynthesis. Species with cotyledon reserve type were more than foliar cotyledons type (43 species and 22 species, respectively). The proportion of seedling types CER (cryptocotylar-epigeal-reservoir), CHR (cryptocotylar-hypogeal-reservoir), PEF (phanerocotylar-epigeal-foliaceous), PER (phanerocotylar-epigeal-reservoir), PHR (phanerocotylar-hypogeal-reservoir) were 3.08%, 16.92%, 33,85%, 29,23%, 16,92%, respectively.


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