scholarly journals Influența restricțiilor hidrice asupra fungului Fusarium Solani Var. Coeruleum

2020 ◽  
Author(s):  
Elena Sasco ◽  
Keyword(s):  
Fusarium Solani ◽  
Aerial Mycelium ◽  
High Survival ◽  
Considerable Decrease ◽  
Survival Capacity ◽  
Influence Of Water ◽  
Water Restrictions

The article presents data on the influence of water restrictions on the fungi Fusarium solani var. coeruleum. The considerable decrease of the share of the strain factor from 68.88% to 16.97% for F. solani, denotes the high survival capacity of the fungus in conditions of osmotic restrictions produced by the osmotic substance PEG, thus confirming the data from the literature. The spread of the mycelium in the form of plaque or film, the intensity of pigmentation, the presence of aerial mycelium show changes in the adaptation of the fungus to osmotic conditions, which have significantly affected the growth of F. solani.

scholarly journals Fusarium Canker of Bitternut Hickory Caused by Fusarium solani in the North-Central and Northeastern United States

Plant Disease ◽  
2012 ◽  
Vol 96 (3) ◽  
pp. 455-455 ◽  
Author(s):  
J.-H. Park ◽  
J. Juzwik
Keyword(s):  
United States ◽  
Fusarium Solani ◽  
Apical Cell ◽  
Elongation Factor ◽  
Morphological Characteristics ◽  
Aerial Mycelium ◽  
The United States ◽  
Eastern United States ◽  
Gene Sequences ◽  
Inner Bark

Multiple annual cankers were observed on the upper main stems of bitternut hickory (Carya cordiformis) exhibiting top dieback in Indiana, Iowa, Minnesota, New York, Ohio, and Wisconsin during a 2006 to 2008 survey of declining hickory. The top-killed trees had normal-sized, green leaves below and the cankers were oval, sunken, and bounded by heavy callus that seemed to arrest further canker expansion. Fusarium solani was consistently isolated from the margins of inner bark lesions or discolored sapwood of the cankers. When cultured on potato dextrose agar, the isolates grew rapidly with abundant aerial mycelium. On carnation leaf agar, thick-walled macroconidia with 4 to 5 septa were produced in cream, blue-green, or blue sporodochia. Macroconidia were generally cylindrical with a blunt or rounded apical cell and a rounded or foot-shaped basal cell. Microconidia were oval to kidney shaped with 0 to 1 septa and were produced in false heads on elongate monophialides. Chlamydospores were formed singly or in pairs. These morphological characteristics are consistent with descriptions of F. solani (2). The identities of 42 representative isolates were confirmed by sequencing the translation elongation factor (tef) 1-α gene. BLAST analysis of the sequences from each isolate against the GenBank and FUSARIUM-ID database found 98 to 100% similarities to F. solani isolates (GenBank Accession Nos. DQ246841, DQ247025, DQ247282, and DQ247436 and FUSARIUM-ID isolate FD01041). Two haplotypes (BB and BC) were distinguished based on the tef 1-α gene sequences that differed by 10 bp. Pathogenicity tests were conducted with two isolates of each haplotype on asymptomatic C. cordiformis (12 to 21 cm in diameter) in forest stands. In May 2009 in Wabasha County, MN, 0.1-ml spore suspensions (1 × 104 macroconidia/ml) or sterile water was placed in one of three holes (0.6 cm in diameter) drilled to the cambium of 12 trees. The holes were sealed with moist cotton and moldable putty. A duplicate trial, but with BB and BC isolates from Wisconsin, was initiated in Chippewa County, WI in June 2009. The extent of inner bark necrosis was assessed 13 months after inoculation in both sites. Inoculations with F. solani in Minnesota resulted in inner bark lesions with average lengths of 20 and 30 mm for the BB and BC haplotypes, respectively. In Wisconsin, BB and BC haplotypes caused inner bark lesions with average lengths of 34 and 38 mm, respectively. While sunken or open cankers were found for all the BC isolate inoculations, relatively small and callus-bounded cankers were found for BB isolate inoculations. All control wounds were callus-closed with average wound lengths of 12 and 23 mm in Minnesota and Wisconsin, respectively. The same haplotype of F. solani used for inoculation was recovered from each canker as confirmed by analysis of tef 1-α gene sequences. F. solani was not obtained from control wounds. To our knowledge, this is the first report of a canker caused by F. solani on bitternut hickory (1). The same fungus has been previously reported to cause cankers on stems of other hardwood tree genera in the eastern United States and Canada. We hypothesize that numerous main-stem cankers caused by F. solani lead to top dieback of bitternut hickory. References: (1) D. F. Farr et al. Fungi on Plants and Plant Products in the United States. The American Phytopathological Society, St. Paul, MN, 1989. (2) J. F. Leslie and B. A. Summerell. The Fusarium Laboratory Manual. Blackwell Publishing, Ames, IA, 2006.

Adaptive Growth Responses of Listeria monocytogenes to Acid and Osmotic Shifts above and across the Growth Boundaries

2011 ◽  
Vol 74 (1) ◽  
pp. 78-85 ◽  
Author(s):  
C.-I. A. BELESSI ◽  
Y. LE MARC ◽  
S. I. MERKOURI ◽  
A. S. GOUNADAKI ◽  
S. SCHVARTZMAN ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Cell Injury ◽  
Meat Products ◽  
Injury Rate ◽  
Growth Conditions ◽  
High Survival ◽  
Growth Responses ◽  
Survival Capacity ◽  
Lag Times ◽  
Fermented Dairy

The effect of acid and osmotic shifts on the growth of Listeria monocytogenes was evaluated at 10°C. Two types of shifts were tested: (i) within the range of pH and water activity (aw) levels that allow growth of L. monocytogenes and (ii) after habituation at no-growth conditions back to growth-permitting conditions. A L. monocytogenes cheese isolate, with high survival capacity during cheesemaking, was inoculated (102 CFU/ml) in tryptic soy broth supplemented with 0.6% yeast extract at six pH levels (5.1 to 7.2; adjusted with lactic acid) and 0.5% NaCl (aw 0.995), or four aw levels (0.995 to 0.93, adjusted with 0.5 to 10.5% NaCl) at pH 7.2 and grown to early stationary phase. L. monocytogenes was then shifted (at 102 CFU/ml) to each of the aforementioned growth-permitting pH and aw levels and incubated at 10°C. Shifts from no-growth to growth-permitting conditions were carried out by transferring L. monocytogenes habituated at pH 4.9 or aw 0.90 (12.5% NaCl) for 1, 5, and 10 days to all pH and aw levels permitting growth. Reducing aw or pH at different levels in the range of 0.995 to 0.93 and 7.2 to 5.1, respectively, decreased the maximum specific growth rate of L. monocytogenes. The lag time of the organism increased with all osmotic downshifts, as well as by the reduction of pH to 5.1. Conversely, any type of shift within pH 5.5 to 7.2 did not markedly affect the lag times of L. monocytogenes. The longer the cells were incubated at no-growth aw (0.90), the faster they initiated growth subsequently, suggesting adaptation to osmotic stress. Conversely, extended habituation at pH 4.9 had the opposite effect on subsequent growth of L. monocytogenes, possibly due to cell injury. These results suggest that there is an adaptation or injury rate induced at conditions inhibiting the growth of the pathogen. Thus, quantifying adaptation phenomena under growth-limiting environments, such as in fermented dairy and meat products or products preserved in brine, is essential for reliable growth simulations of L monocytogenes during transportation and storage of foods.

scholarly journals First report of Fusarium falciforme (FSSC 3+4) causing root rot on chickpea in Mexico

Plant Disease ◽  
2021 ◽  
Author(s):  
Sixto Velarde Felix ◽  
Victor Valenzuela ◽  
Pedro Ortega ◽  
Gustavo Fierros ◽  
Pedro Rojas ◽  
...  
Keyword(s):  
Fusarium Solani ◽  
Root Rot ◽  
Species Complex ◽  
Elongation Factor ◽  
Morphological Characteristics ◽  
Aerial Mycelium ◽  
Pathogenicity Test ◽  
Conidial Suspension ◽  
Single Spore ◽  
First Report

Chickpea (Cicer aretinium L.) is a legume crop of great importance worldwide. In January 2019, wilting symptoms on chickpea (stunted grow, withered leaves, root rot and wilted plants) were observed in three fields of Culiacan Sinaloa Mexico, with an incidence of 3 to 5%. To identify the cause, eighty symptomatic chickpea plants were sampled. Tissue from roots was plated on potato dextrose agar (PDA) medium. Typical Fusarium spp. colonies were obtained from all root samples. Ten pure cultures were obtained by single-spore culturing (Ff01 to Ff10). On PDA the colonies were abundant with white aerial mycelium, hyphae were branched and septae and light purple pigmentation was observed in the center of old cultures (Leslie and Summerell 2006). From 10-day-old cultures grown on carnation leaf agar medium, macroconidias were falciform, hyaline, with slightly curved apexes, three to five septate, with well-developed foot cells and blunt apical cells, and measured 26.6 to 45.8 × 2.2 to 7.0 μm (n = 40). The microconidia (n = 40) were hyaline, one to two celled, produced in false heads that measured 7.4 to 20.1 (average 13.7) μm × 2.4 to 8.9 (average 5.3) μm (n = 40) at the tips of long monophialides, and were oval or reniform, with apexes rounded, 8.3 to 12.1 × 1.6 to 4.7 μm; chlamydospores were not evident. These characteristics fit those of the Fusarium solani (Mart.) Sacc. species complex, FSSC (Summerell et al. 2003). The internal transcribed spacer and the translation elongation factor 1 alpha (EF1-α) genes (O’Donnell et al. 1998) were amplified by polymerase chain reaction and sequenced from the isolate Ff02 and Ff08 (GenBank accession nos. KJ501093 and MN082369). Maximum likelihood analysis was carried out using the EF1-α sequences (KJ501093 and MN082369) from the Ff02 and Ff08 isolates and other species from the Fusarium solani species complex (FSSC). Phylogenetic analysis revealed the isolate most closely related with F. falciforme (100% bootstrap). For pathogenicity testing, a conidial suspension (1x106 conidia/ml) was prepared by harvesting spores from 10-days-old cultures on PDA. Twenty 2-week-old chickpea seedlings from two cultivars (P-2245 and WR-315) were inoculated by dipping roots into the conidial suspension for 20 min. The inoculated plants were transplanted into a 50-hole plastic tray containing sterilized soil and maintained in a growth chamber at 25°C, with a relative humidity of >80% and a 12-h/12-h light/dark cycle. After 8 days, the first root rot symptoms were observed on inoculating seedlings and the infected plants eventually died within 3 to 4 weeks after inoculation. No symptoms were observed plants inoculated with sterilized distilled water. The fungus was reisolated from symptomatic tissues of inoculated plants and was identified by sequencing the partial EF1-α gene again and was identified as F. falciforme (FSSC 3 + 4) (O’Donnell et al. 2008) based on its morphological characteristics, genetic analysis, and pathogenicity test, fulfilling Koch’s postulates. The molecular identification was confirmed via BLAST on the FusariumID and Fusarium MLST databases. Although FSSC has been previously reported causing root rot in chickpea in USA, Chile, Spain, Cuba, Iran, Poland, Israel, Pakistan and Brazil, to our knowledge this is the first report of root rot in chickpea caused by F. falciforme in Mexico. This is important for chickpea producers and chickpea breeding programs.

scholarly journals Identification of Soybean Genotypes Resistant to Charcoal Rot by Seed Inoculation With Macrophomina phaseolina

2019 ◽  
Vol 11 (7) ◽  
pp. 213
Author(s):  
Mayra S. Ishikawa ◽  
Neucimara R. Ribeiro ◽  
Adriély A. de Almeida ◽  
Maria Isabel Balbi-Peña
Keyword(s):  
Soybean Seed ◽  
Macrophomina Phaseolina ◽  
Natural Soil ◽  
Screening Methods ◽  
High Survival ◽  
Charcoal Rot ◽  
Seed Inoculation ◽  
Survival Capacity ◽  
Soybean Genotypes ◽  
Pathogenic Variability

Soybean charcoal rot is a widespread root disease caused by the fungus Macrophomina phaseolina, a natural soil inhabitant that has great pathogenic variability and high survival capacity under adverse conditions. There are no registered fungicides or genotypes genetically resistant to this disease, although differences in susceptibility have been observed. As the fungus is a seed-borne pathogen, screening methods based on seed inoculation are quick and efficient. The objective of this work was to assess the efficiency of soybean seed infestation by incubation for 48 h with colonies of M. phaseolina, comparing two germination environment methods (germination paper or in pots with substrate), and to correlate the relative germination of genotypes of both methods with the severity of charcoal rot observed in a field test. The results showed that 48 h were sufficient to infest seeds and reduce the germination. The germination in paper was higher at 5 days after sowing (DAS) than that in pots at 8 DAS in a greenhouse. Both environments exhibited a highly negative correlation between seed germination and field disease severity (r = -0.775 in germination paper and r = -0.779 in pots with substrate). It is recommended that the germination test be performed in germination paper due to practicality and economy of space, material, and labor besides the better control of the environment.

scholarly journals Functional characteristics of lactobacilli from traditional Bulgarian fermented milk products

2019 ◽  
pp. 148-153
Author(s):  
Veronica NEMSKA ◽  
Petya LOGAR ◽  
Tanya RASHEVA ◽  
Zdravka SHOLEVA ◽  
Nelly GEORGIEVA ◽  
...  
Keyword(s):  
Fermented Milk ◽  
Model Systems ◽  
High Survival ◽  
Duration Of Action ◽  
Protection Systems ◽  
Survival Capacity ◽  
Small Intestinal ◽  
Vitro Model ◽  
Probiotic Lactobacilli

After oral administration, probiotic lactobacilli meet a number of protection systems in the human body, such as exposure to gastric, pancreatic, and small intestinal juices. Overcoming these detrimental barriers allows living bacteria to adhere to the intestinal epithelium and permanently colonize the gastrointestinal tract (GIT), providing health benefits to the host. Based on this, the transit tolerance of 25 candidate probiotic lactobacilli from katak, yoghurt, and white-brined and yellow cheese to simulated bile and small intestinal juices of variable pH was investigated. To establish their resistance, in vitro model systems based on modified MRS media and a longer duration of action (up to 24 h of incubation) were designed. Six of the strains studied were found to show strain-specific survival capacity with low viability in conditions simulating stomach acidity and high resistance to bile and intestinal juices. In addition, the adherence capability (autoaggregation and hydrophobicity) of the strains was determined. Obtained results allowed to select Lactobacillus strains with high survival ratios while passing through the GIT and good adherence properties, which make them suitable for the development of new probiotics.

Interleukin-7 and infection itself by human immunodeficiency virus 1 favor virus persistence in mature CD4+CD8−CD3+ thymocytes through sustained induction of Bcl-2

Blood ◽  
2001 ◽  
Vol 98 (7) ◽  
pp. 2166-2174 ◽  
Author(s):  
Eric Guillemard ◽  
Marie-Thérèse Nugeyre ◽  
Laurent Chêne ◽  
Nathalie Schmitt ◽  
Catherine Jacquemot ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Hiv Infection ◽  
High Yield ◽  
High Survival ◽  
Double Positive ◽  
Interleukin 7 ◽  
Sequence Of Events ◽  
Immunodeficiency Virus ◽  
Survival Capacity

The sequence of events and the mechanisms leading to the destruction of the thymus during human immunodeficiency virus (HIV) infection are still poorly characterized. Investigated here are the survival capacity on HIV-1 infection of the mature single-positive CD4+CD8−CD3+ (SP CD4+) and the intermediate CD4+ CD8−CD3− thymocytes previously shown to be able to replicate the virus in the thymic microenvironment. It is demonstrated that the mature SP CD4+ thymocytes exhibit a high survival capacity despite the production of a high yield of viruses. Interleukin-7, reported to be a crucial cofactor of tumor necrosis factor (TNF) to promote HIV replication, is shown here to counteract the apoptotic activity of TNF. Resistance to apoptosis of SP CD4+ cells is conferred by a high expression of the IL-7 receptor (IL-7R) associated with the capacity of IL-7 to permanently up-regulate Bcl-2. In addition, this high Bcl-2 level is further enhanced by infection itself. In contrast, intermediate thymocytes, which replicate the virus at a lower level, are more sensitive to apoptosis, and their differentiation into double-positive CD4+CD8+CD3− (DP CD3−) cells strongly increases their death rate on infection. This sensitivity is related to a lower expression of IL-7R and Bcl-2 in intermediate thymocytes, which further decreases at the DP CD3− stage. In addition, a decreased level of Bcl-2 is observed in this subset during infection. Altogether these data suggest that in vivo, HIV infection might create a persistent virus reservoir within the SP CD4+ thymocytes, whereas the later infection of intermediate cells might lead to thymopoiesis failure.

scholarly journals A STUDY OF POTENTIAL LISTERIOSIS: AN EMERGING FOOD-BORNE DISEASE

2019 ◽  
pp. 110-117
Author(s):  
S. Yu Soldatova ◽  
G. L Filatova ◽  
T. S Kulikovskaya
Keyword(s):  
Raw Materials ◽  
Food Contamination ◽  
High Survival ◽  
Parasitic Mode ◽  
Food Borne ◽  
Survival Capacity ◽  
Mode Of Life ◽  
Proactive Measures ◽  
Meat Samples ◽  
Isolated Species

The incidence of listeriosis has been rising 1980s. Epidemic outbreaks are becoming more widespread and are accompanied by high mortality. The most common cause of infectionis consumption of food contaminated with pathogenic Listeria species, in particular L. monocytogenes . Listeria bacteria are psychrophiles, live in all media of the environment, and easily move from saprotrophic to parasitic mode of life. All these qualities have provided them with adaptability and high survival capacity. The sources of food contamination with Listeria bacteria usually are contaminated raw materials or equipment of food production facilities. Deep frozen beef blocks were tested for contamination with Listeria bacteria that were detected and identified by bacteriological technique and enzyme immunoassayand immunochromatographic assay. Listeria bacteria were found in 35% of samples but there were no pathogenic species among them. The isolated species were identified as L. innocua, L. welshimeri, L. grayi and L. seeligeri . These species often colonisevarious media of the environment. The examined meat samples were found to be safe. Listeriosis can be prevented by systemic proactive measures including sanitary and epidemiological control of food raw materials and finished products, properly organized technological process, and hygienic education of the population.

scholarly journals Fusarium Crown and Root Rot of Tarragon in California Caused by Fusarium solani

Plant Disease ◽  
2011 ◽  
Vol 95 (6) ◽  
pp. 768-768 ◽  
Author(s):  
S. T. Koike
Keyword(s):  
Fusarium Solani ◽  
Root Rot ◽  
Fusarium Species ◽  
Aerial Mycelium ◽  
State University ◽  
Root Cortex ◽  
Perennial Plant ◽  
Initial Symptoms ◽  
Crown And Root Rot ◽  
Rot Disease

Tarragon, also known as estragon or dragon's-wort (Artemisia dracunculus), is a perennial plant in the Asteraceae. Tarragon is grown for use in cooking as a fresh and dried herb. In May 2010, commercial tarragon grown in a field on California's central coast was affected by a previously undescribed disease. Initial symptoms consisted of chlorosis of leaves and wilting of shoot tips. As the disease progressed, entire shoots and branches turned brown and died. The plant crown epidermis and cortex and the upper cortex of the main roots turned brown with occasional black streaking. Diseased plants died several weeks after the onset of wilting. A Fusarium species was consistently isolated from symptomatic crown and root tissues. On carnation leaf agar (CLA) incubated under lights, the isolates produced stout, slightly curved macroconidia having blunt apical cells. One- and two-celled oval to cylindrical microconidia were abundant and born in false heads on extremely long monophialides. Chlamydospores were present in 1-month-old cultures. On potato dextrose agar incubated under lights, the isolates produced abundant white aerial mycelium with bluish coloration of the culture surface. The isolates were identified as Fusarium solani (2). Pathogenicity tests were conducted using six isolates, with inoculum produced on CLA. For each isolate, 250 ml of a spore suspension (1 × 106 conidia/ml) were poured onto the roots of 10-cm potted tarragon plants. Ten plants were inoculated for each of the six isolates. A control set of tarragon was treated with 250 ml of water. All plants were maintained in a greenhouse set at 24 to 25°C. After 8 weeks, plants inoculated with the spore suspensions began to show wilting and browning of leaves. Crown epidermis and cortex and root cortex tissues were brown; Fusarium solani was reisolated from the crowns and roots. The experiment was repeated and the results were the same. To my knowledge, this is the first report of F. solani causing a crown and root rot disease of tarragon. The disease caused significant damage with approximately 50% of the commercial field affected. The other Fusarium species previously reported on tarragon is an uncharacterized F. oxysporum isolated from roots of plants grown in California (1). References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , March 8, 2011, (2) P. E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. Pennsylvania State University Press, University Park, PA, 1983.

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