Effect of calcium on the growth and virulence of Phytophthora clandestina

2000 ◽  
Vol 40 (1) ◽  
pp. 47 ◽  
Author(s):  
S. Simpfendorfer ◽  
T. J. Harden
Keyword(s):  
Fungal Pathogen ◽  
Mycelial Growth ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
In Vitro Growth ◽  
Seedling Biomass ◽  
Pathogenic Races ◽  
Glasshouse Experiment ◽  
The Individual

Calcium was found to significantly stimulate both the mycelial growth and virulence of Phytophthora clandestina, the major soilborne fungal pathogen of subterranean clover (Trifolium subterraneum L.). On average, the addition of calcium as either CaCO3 or CaCl2 to 3 artificial media increased the in vitro growth of 15 isolates from 20 to 135%. Calcium was also shown to increase the severity of root disease caused by 6 isolates of P. clandestina by up to 100% in a glasshouse experiment. The addition of Ca2+ as CaCl2 had a greater stimulatory effect on the virulence of P. clandestina towards cv. Woogenellup seedlings (up to 57% reduction in seedling biomass) than supplementing with CaCO3 (maximum 36% decrease). The virulence of 6 isolates from 3 different pathogenic races of P. clandestina were examined in the glasshouse experiment. Differences in the virulence of P. clandestina towards cv. Woogenellup seedlings was shown to be dependent on the individual isolate rather than the pathogenic race to which it is assigned.

scholarly journals Suppression of Stem-End Rot on Avocado Fruit Using Trichoderma spp. in the Central Highlands of Kenya

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
E. K. Wanjiku ◽  
J. W. Waceke ◽  
J. N. Mbaka
Keyword(s):  
Growth Inhibition ◽  
Fungal Pathogen ◽  
Mycelial Growth ◽  
Culture Technique ◽  
Global Market ◽  
Dual Culture ◽  
Postharvest Diseases ◽  
Trichoderma Spp ◽  
Lasiodiplodia Theobromae

Demand for organic avocado fruits, together with stringent food safety standards in the global market, has made producers to use alternative, safe, and consumer-friendly strategies of controlling the postharvest fungal disease of avocado fruits. This study assessed the in vitro efficacy of Trichoderma spp. (T. atroviride, T. virens, T. asperellum, and T. harzianum) against isolated avocado stem-end rot (SER) fungal pathogens (Lasiodiplodia theobromae, Neofusicoccum parvum, Nectria pseudotrichia, and Fusarium solani) using a dual culture technique. The Trichoderma spp. were also evaluated singly on postharvest “Hass” avocado fruits. Spore suspension at 5 × 104 conidial/ml of the Trichoderma spp. was applied on the avocado fruits at three time points, twenty-four hours before the fungal pathogen (preinoculation), at the same time as the fungal pathogen (concurrent inoculation), and 24 hours after the fungal pathogen (postinoculation). In the in vitro study, T. atroviride showed the highest mycelial growth inhibition against N. parvum (48%), N. pseudotrichia (55%), and F. solani (32.95%), while T. harzianum had the highest mycelial growth inhibition against L. theobromae. Trichoderma asperellum was the least effective in inhibiting the mycelial growth of all the pathogens. Similarly, T. virens showed the highest mycelial growth inhibition against N. pseudotrichia at 45% inhibition. On postharvest “Hass” fruits, T. atroviride showed the highest efficacy against N. parvum, N. pseudotrichia, and F. solani in all the applications. Trichoderma virens and T. harzianum were most effective against all the pathogens during postinoculation, while Lasiodiplodia theobromae was best controlled by T. virens, T. harzianum, and T. asperellum during postinoculation. Both T. atroviride and T. harzianum present a potential alternative to synthetic fungicides against postharvest diseases of avocado fruits, and further tests under field conditions to be done to validate their efficacy. The possibility of using Trichoderma spp. in the management of SER on avocado fruits at a commercial level should also be explored.

Comparison of single superphosphate and superphosphate coated with bauxite residue for subterranean clover production on phosphorus-leaching soils

Soil Research ◽  
2000 ◽  
Vol 38 (3) ◽  
pp. 735 ◽  
Author(s):  
Robert Summers ◽  
Martin Clarke ◽  
Tim Pope ◽  
Tim O'Dea
Keyword(s):  
Field Experiment ◽  
Soil Phosphorus ◽  
Bauxite Residue ◽  
Phosphorus Uptake ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Single Superphosphate ◽  
Glasshouse Experiment ◽  
The Impact ◽  
Coated Granules

Bauxite residue from alumina refining was used to coat granules of single superphosphate to reduce the leaching of phosphorus in coarse, sandy soils for pastures in high rainfall areas of south-western Australia (>800 mm annual average). The impact of coating the superphosphate on the leaching of phosphorus was measured in a glasshouse experiment and the effectiveness of the fertiliser using dry herbage yield of subterranean clover (Trifolium subterraneum) was measured in a field experiment. The glasshouse experiment measured the effect of coating the superphosphate with bauxite residue at 0, 5, 10, 15, 20, 25, 30, 35, and 40% by weight. A coating of 25% (by weight) was chosen for the field experiment. In the glasshouse experiment, the coated granules were applied to columns of soil, where subterranean clover was grown under leaching conditions. A coating of 30%, by weight, reduced leaching of single superphosphate by about half. Increasing the coating of bauxite residue also increased the phosphorus uptake and increased the plant growth. In the field trial, the effectiveness of single superphosphate with a bauxite residue coating of 25% by weight was increased on average by 100% in Year 1, 303% in Year 2, and 158% in Year 3, relative to freshly applied single superphosphate. The bauxite residue coating also increased the phosphorus content of the herbage in a similar manner to the increases in yield. Limited soil phosphorus tests showed only minor increases in the residues of phosphorus where the superphosphate had been coated with bauxite residue.

The in vitro inhibition of Phytophthora clandestina by some rhizobia and the possible role of Rhizobium trifolii in biological control of Phytophthora root rot of subterranean clover

1999 ◽  
Vol 50 (8) ◽  
pp. 1469 ◽  
Author(s):  
S. Simpfendorfer ◽  
T. J. Harden ◽  
G. M. Murray
Keyword(s):  
Biological Control ◽  
Root Rot ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Disease ◽  
Rhizobium Trifolii ◽  
Biological Control Agents ◽  
Control Activity ◽  
Phytophthora Root Rot

The interaction between 29 isolates of Rhizobium and the in vitro growth of 3 strains of Phytophthora clandestina was investigated to determine the potential of these bacteria as biological control agents against root rot of subterranean clover (Trifolium subterraneum L.). The biological control activity of Rhizobium on the severity of root disease in seedlings was also investigated under glasshouse conditions. Thirteen of the 29 Rhizobium isolates caused significant reductions in the hyphal growth of the 3 P. clandestina isolates examined. Inoculation of seedlings with Rhizobium trifolii reduced the severity of root disease by 14–58% with corresponding increases in dry matter production of 20–73%. These results indicate that Rhizobium species have potential as biological control agents against the root rot of T. subterraneum seedlings caused by P. clandestina.

Plant factors influencing the nutritive value of some temperate annual pasture species

1973 ◽  
Vol 13 (63) ◽  
pp. 404 ◽  
Author(s):  
JG McIvor ◽  
DF Smith
Keyword(s):  
Nutritive Value ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growth Cycle ◽  
Matter Content ◽  
In Vitro Digestibility ◽  
Dry Matter Content ◽  
Hordeum Leporinum ◽  
Brome Grass

Changes in herbage production, dry matter content, nitrogen content and in vitro digestibility of two sown species-subterranean clover (Trifolium subterraneum) and annual ryegrass (Lolium rigidum) - and five common volunteer species-capeweed (Arctotheca calendula), musky crowfoot (Erodium moschatum), barley grass (Hordeum leporinum), ripgut brome grass (Bromus rigidus) and soft brome grass (Bromus mollis)-were measured throughout their growth cycle. The volunteer species compared favourably with the sown species for these measurements and should be capable of providing nutritious grazing for animals.

Alternative and sustainable control of the fungus Sclerotinia sclerotiorum that causes white mold in soybeans

2021 ◽  
Author(s):  
Sergio E. Lemos da Silva ◽  
Kimberlly Soares Brito Bratifich ◽  
eloisa Teresa Corradini Santos
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Agricultural Production ◽  
Mycelial Growth ◽  
Direct Relationship ◽  
White Mold ◽  
Phytopathogenic Fungus ◽  
Environmental Damage ◽  
In Vitro Growth ◽  
Negative Effect

The Sclerotinia sclerotiorum is a phytopathogenic fungus that causes the White Mold of soybean, being responsible for losses of up to 100% in agricultural production. The objective of this work was to verify and analyze the effect of the raw aqueous extract (EBA) of ginger Zingiber officinalis on a strain of Sclerotinia Sclerotiorum isolated from soybean, cultivated and maintained in vitro in laboratory. The methodology consisted of a longitudinal study of the statistical analysis of the mycelial growth velocity index (MICV), after treatment of the mycelia with different concentrations of aqueous crude extract. The results showed a direct relationship between increasing concentration of EBA and a significant negative effect on the growth of scleroderia. It was possible to conclude that the antifungal activity of ginger EBA was able to inhibit the in vitro growth of Sclerotinia sclerotiorum, with potential protection of soybean crops; it can become a sustainable alternative in the control of this fungus, by decreasing the use of agrochemicals that cause damage to public health and environmental damage.

scholarly journals Specific erythrocyte binding is an additional nutrient acquisition system for Trichomonas vaginalis.

1990 ◽  
Vol 171 (6) ◽  
pp. 2165-2170 ◽  
Author(s):  
M W Lehker ◽  
T H Chang ◽  
D C Dailey ◽  
J F Alderete
Keyword(s):  
Trichomonas Vaginalis ◽  
Surface Proteins ◽  
In Vitro Growth ◽  
Specific Receptor ◽  
Hemoglobin Binding ◽  
Erythrocyte Binding ◽  
The Individual ◽  
Erythrocyte Lipids

Specific receptor-mediated binding by Trichomonas vaginalis of human erythrocytes was demonstrated. The ability of live parasites to internalize erythrocytes was also documented. In vitro growth assays during lipid-free and iron-limiting conditions that do not support the survival of T. vaginalis organisms showed that purified erythrocyte lipids and hemoglobin were each able to provide lipids and/or hemoglobin iron for trichomonal growth and multiplication. Parasites bound hemoglobin in a highly specific receptor-mediated fashion, and only the homologous unlabeled hemoglobin, but not lactoferrin and transferrin, competed with iodinated hemoglobin binding. Two antibody-crossreactive surface proteins of the parasites were identified as adhesins, and antibody to the individual adhesins inhibited T. vaginalis recognition and binding of erythrocytes. Finally, patient sera possessed antibody to the adhesins, showing the immunogenic nature and in vivo relevance of the trichomonad proteins during infection.

In vitro growth of some species of Ascochyta Lib.

2012 ◽  
Vol 7 (6) ◽  
pp. 1076-1083
Author(s):  
Tomasz Kosiada
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Mycelial Growth ◽  
Potato Dextrose Agar ◽  
In Vitro Growth ◽  
Light Conditions ◽  
Oatmeal Agar ◽  
The Family ◽  
Effects Of Temperature

AbstractFungi from the genus Ascochyta are generally facultative saprotrophs, which cause diseases in both monocots and dicots. Over 1 000 species belonging to this genus have been identified, 18 of which infect monocot plants from the family Poaceae. This study analyses the effects of temperature and light on the growth of selected fungi which infect monocots (A. agrostidis, A. avenae, A. brachypodii, A. desmazieri, A. digraphidis, A. ducis-aprutii, A. festucae, A. graminea, A. hordei, A. hordei var. americana, A. hordei var. europea, A. hordei var. hordei, A. melicae, A. phleina, A. skagwayensis, A. sorghi, A. stipae, A. zeicola), grown on three types of media; Potato Dextrose Agar (PDA), Coon’s agar (CN) and oatmeal agar (OMA). The fastest growth among the analyzed fungi at low temperatures was found in Ascochyta melicae, while at high temperatures it was A. zeicola. The fastest in vitro growth (average of all fungi) was observed on CN medium at 20°C (3.4 mm/day), while the lowest on OM medium at 5°C (1.0 mm/day). Radial mycelial growth in dark and the light conditions varied. On average, all isolates grew faster in the dark (3.1 mm/day) than in the light (1.9 mm/day). The greatest effect on the production of pycnidia was found for the isolates. Variation in growth and production of pycnidia depended on temperature, medium and lighting for fungi from the genus Ascochyta infecting monocots. Such variation indicates a potential occurrence of these fungi in different environments.

Phosphate applied to soil increases the effectiveness of subsequent applications of phosphate for growing wheat shoots

1998 ◽  
Vol 38 (8) ◽  
pp. 865 ◽  
Author(s):  
M. D. A. Bolland ◽  
M. J. Baker
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Phosphorus Retention ◽  
Single Superphosphate ◽  
Mitscherlich Equation ◽  
Curvature Coefficient ◽  
Glasshouse Experiment ◽  
Phosphorus Application ◽  
The Relationship ◽  
Field Plots

Summary. Amounts of phosphorus ranging from 0 to 599 kg P/ha were applied as single (ordinary) superphosphate once only in 1976 to plots of a field experiment on a lateritic ironstone gravel sand. Subterranean clover (Trifolium subterraneum) and cereals (wheat, Triticum aestivum, and barley, Hordeum vulgare) were grown in rotation on the plots for 20 years after phosphorus application. In 1996, samples of the <2 mm fraction of the top 10 cm of soil were collected from the field plots to measure phosphorus retention by soil and for a glasshouse experiment. The phosphorus retention index, a measure of the capacity of the soil to sorb phosphorus, decreased from 35 to 2 mL/g as the amount of phosphorus applied 20 years previously increased from 0 to 599 kg/ha. In the glasshouse experiment, wheat was grown for 35 days in soil to which 9 amounts of freshly-applied powdered single superphosphate (0, 0.0125, 0.025, 0.05, 0.1, 0.2, 0.4, 0.8 and 1.6 g P/pot, for 1.8 kg soil/pot) were applied to the original phosphorus treatments. The value of the curvature coefficient of the Mitscherlich equation fitted to the relationship between yield of dried shoots and the amount of fresh-phosphorus applied increased with increasing amount of phosphorus applied 20 years previously. That is, the fresh-phosphorus treatments became more effective for producing dried wheat shoots as the amount of previously applied phosphorus increased.

scholarly journals Agronomic characteristics of annual Trifolium legumes and nutritive values as predicted by near-infrared reflectance (NIR) spectroscopy

2011 ◽  
Vol 62 (12) ◽  
pp. 1078 ◽  
Author(s):  
X. Li ◽  
R. L. Ison ◽  
R. C. Kellaway ◽  
C. Stimson ◽  
G. Annison ◽  
...  
Keyword(s):  
Organic Matter ◽  
Near Infrared ◽  
Spectral Characteristics ◽  
Nir Spectroscopy ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Infrared Reflectance ◽  
Near Infrared Reflectance ◽  
Stem Leaf

A range of annual legume genotypes comprising one line of Trifolium subterraneum, four lines of T. michelianum, 11 of T. resupinatum var. resupinatum, and one line of T. resupinatum var. majus were grown in glasshouses under temperature regimes of 10−15°C and 16−21°C. Dry matter (DM) weights of stem, leaf, and flower tissues were measured when plants had six nodes, at first flower appearance, and at senescence. All samples were scanned by near-infrared reflectance spectroscopy (NIRS). One-third of the samples, covering the range of spectral characteristics, were analysed for in vitro digestible organic matter (DOMD), organic matter, crude protein (CP), neutral detergent fibre (NDF), lignin, cellulose, and the hemicellulosic polysaccharide monomers arabinose, xylose, mannose, galactose, and rhamnose. These data were used to develop calibration equations from which the composition of the remaining samples was predicted by NIRS. The higher temperature resulted in plants reaching respective phenological stages earlier, but did not affect either DM yields of total plant, stem, leaf, and petiole tissues or the proportions of each fraction. In vitro DOMD and arabinose and galactose levels decreased, while lignin, cellulose, NDF, xylose, mannose, and rhamnose levels increased with advancing maturity. In vitro DOMD was positively associated with contents of CP, arabinose, galactose, and the arabinose/xylose ratio and was negatively associated with contents of lignin, cellulose, NDF, xylose, mannose, and rhamnose. Lignin contents were highly correlated with levels of both xylose and mannose. Stems were more digestible than leaves in subterranean clover and T. resupinatum var. majus. The study also demonstrated that NIRS can be used routinely as a quick, inexpensive, and reliable laboratory technique to predict feed components of annual Trifolium legumes.

scholarly journals Virulence of the Fungal Pathogen Candida albicans Requires the Five Isoforms of Protein Mannosyltransferases

2005 ◽  
Vol 73 (8) ◽  
pp. 4571-4580 ◽  
Author(s):  
Mahmoud Rouabhia ◽  
Martin Schaller ◽  
Cristina Corbucci ◽  
Anna Vecchiarelli ◽  
Stephan K.-H. Prill ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Mouse Model ◽  
Fungal Pathogen ◽  
Antifungal Agents ◽  
Three Dimensional ◽  
Secretory Proteins ◽  
In Vitro Growth ◽  
Specific Host ◽  
Three Dimensional Models

ABSTRACT The PMT gene family in Candida albicans encodes five isoforms of protein mannosyltransferases (Pmt proteins Pmt1p, Pmt2p, Pmt4p, Pmt5p, and Pmt6p) that initiate O mannosylation of secretory proteins. We compared virulence characteristics of pmt mutants in two complex, three-dimensional models of localized candidiasis, using reconstituted human epithelium (RHE) and engineered human oral mucosa (EHOM); in addition, mutants were tested in a mouse model of hematogenously disseminated candidiasis (HDC). All pmt mutants showed attenuated virulence in the HDC model and at least one model of localized candidiasis. The pmt5 mutant, which lacks in vitro growth phenotypes, was less virulent in the EHOM and HDC assays but had no consistent phenotype in the RHE assay. In contrast, the pmt4 and pmt6 mutants were less virulent in the RHE and HDC assays but not in the EHOM assay. The results stress the contribution of all Pmt isoforms to the virulence of C. albicans and suggest that the importance of individual Pmt isoforms may differ in specific host niches. We propose that Pmt proteins may be suitable targets for future novel classes of antifungal agents.

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