Effects of phenylthiourea on growth and sclerotial formation of Sclerotium rolfsii and Whetzelinia sclerotiorum

1976 ◽  
Vol 22 (3) ◽  
pp. 379-383 ◽  
Author(s):  
Duane Le Tourneau
Keyword(s):  
Growth Rate ◽  
Liquid Medium ◽  
Sclerotium Rolfsii ◽  
Yellow Pigment ◽  
Potato Dextrose Agar ◽  
Yellowish Green ◽  
Sclerotial Formation ◽  
Synthetic Media ◽  
Whetzelinia Sclerotiorum

The growth rate of Sclerotium rolfsii and Whetzelinia sclerotiorum was reduced when 5 × 10−4 to 2 × 10−3 M l-phenyl-2-thiourea (PTU) was incorporated into synthetic media and potato dextrose agar (PDA). Whetzelinia sclerotiorum produced heavy aerial mycelia and few, if any, sclerotia in synthetic glucose-nitrate liquid medium containing 10−3 and 2 × 10−3 M PTU. At the same PTU concentrations in PDA, W. sclerotiorum formed abnormal sclerotia covered with a yellowish green exudate. Sclerotium rolfsii produced unusual patterns of aerial mycelia and no sclerotia on media containing 2 × 10−3 M PTU. With 5 × 10−4 and 10−3 M PTU, S. rolfsii produced sclerotial initials and some of these developed into atypical clumps of sclerotia. A yellow pigment developed when S. rolfsii grew on media containing PTU.

scholarly journals Evaluation of Activity of Tannases Produced by Isolated from Syrian Woody Soils Trichoderma citrinoviride and T. brevicompactum on Tannins Degradation

2021 ◽  
Vol 39 (2) ◽  
pp. 126-134
Author(s):  
Manal Al-Nhlaoui ◽  
◽  
Adnan Nizam ◽  
Manal Daghestani ◽  
◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Liquid Medium ◽  
Decomposition Rate ◽  
Trichoderma Spp ◽  
Yellowish Green ◽  
Trichoderma Citrinoviride

This study was conducted during the period 2019–2020 to identify Trichoderma spp. isolated from woody soils and assessing their efficacy for biodegradation of tannins through tannase enzyme activity produced. Results obtained confirmed the presence of two species; Trichoderma citrinoviride, which was isolated from Maysalon area near Damascus, and characterized by yellowish green colony with dense growth of spores at the center of the colony, and Trichoderma brevicompactum isolated from the Balluran area near Lattakia characterized by yellow colonies with concentric rings. Trichoderma citrinoviride had higher biodegradation activity, measured by degrading different tannins concentrations (2, 4, 6%) collected from Queircus coccifera from Bmelka area in Tartous in liquid medium and led to 85, 87 and 90% degradation, for the three concentrations, respectively, following 12 days incubation. The activity of the produced tannase was measured to be 37.9 units/mg. Whereas, the decomposition rate of the three tannin concentrations by Trichoderma brevicompactum reached 67, 80 , 89%, respectively, again after 12 days of incubation, with enzyme activity measured to be 35.2 units/mg. Keywords: Trichoderma, tannins, tannase, biodegradation, enzyme activit

scholarly journals Indian Mustard and Allyl Isothiocyanate Inhibit Sclerotium rolfsii

2002 ◽  
Vol 127 (1) ◽  
pp. 27-31 ◽  
Author(s):  
Stephanie G. Harvey ◽  
Heather N. Hannahan ◽  
Carl E. Sams
Keyword(s):  
Treatment Effect ◽  
Radial Growth ◽  
Mycelial Growth ◽  
Sclerotium Rolfsii ◽  
Indian Mustard ◽  
Allyl Isothiocyanate ◽  
Potato Dextrose Agar ◽  
Soilborne Pathogen ◽  
Low Concentrations ◽  
Sclerotial Germination

Allyl isothiocyanate (AITC) is the predominant isothiocyanate produced by damaged tissues of Indian mustard (Brassica juncea (L) Czerniak). This study investigated Indian mustard and AITC mediated suppression of mycelial growth and sclerotial germination of Sclerotium rolfsii Saccardo, a common soilborne pathogen. Indian mustard (IM) treatments of 0, 0.1, 0.2, 0.6, 1.0, 2.0, 4.1, 5.1, 10.2, 20.4, 40.8, 81.6, and 163.3 g·L-1 (weight of reconstituted mustard per liter of air) were evaluated for suppression of mycelial growth. Treatment effect was evaluated by measuring the radial growth of mycelia. Sclerotia were placed in culture tubes containing 18 g autoclaved soil and covered with an additional 5 g soil. AITC at concentrations of 0, 4.0, 16.0, 64.0, 256.0, 1024.0, or 4096.0 μmol·L-1 was injected into the tubes. Treated sclerotia were removed from tubes and plated on potato dextrose agar to determine viability. Mycelial growth was inhibited with IM treatments (P < 0.01). Inhibiting concentrations (IC) of IM for mycelial growth inhibition of 50% and 90% were 0.7 and 1.0 g·L-1, respectively, with death resulting with >2 g·L-1. Inhibition attributable to AITC alone was lower than that achieved by IM producing equivalent amounts of AITC. Germination of sclerotia was negatively correlated with AITC concentration (r = 0.96; P < 0.01). The IC50 and IC90, of AITC were 249.0 and 528.8 μmol·L-1, respectively, at 42 hours. The lethal concentration for sclerotia was not reached; only suppression occurred at the highest treatment concentrations. Sclerotium rolfsii mycelia were sensitive to the IM volatiles and were suppressed at low concentrations. Sclerotia were more resistant than the mycelia and required higher concentrations of AITC to suppress germination.

A comparison between ethanol and methanol as carbon sources for denitrification

1994 ◽  
Vol 30 (6) ◽  
pp. 83-90 ◽  
Author(s):  
Magnus Christensson ◽  
Ewa Lie ◽  
Thomas Welander
Keyword(s):  
Growth Rate ◽  
Carbon Source ◽  
Pure Culture ◽  
Carbon Sources ◽  
Culture Studies ◽  
Adaptation Time ◽  
Synthetic Media ◽  
Short Time

Ethanol and methanol were compared for their performance as carbon sources for denitrification. The study was carried out in two chemostats, operated in parallel on synthetic media containing ethanol and methanol respectively as carbon sources. In addition, pure culture studies were performed on one ethanol- and one methanol-utilizing denitrifier. Ethanol was found to be considerably more readily available as a carbon source for denitrification than was methanol. An efficient denitrification with ethanol was established in a short time, while denitrification with methanol required a substantial adaptation time and never showed the same stability as denitrification with ethanol. The growth rate of denitrifiers with ethanol as carbon source was 2–3 times higher than with methanol. The amount of COD required to denitrify a certain amount of nitrate was somewhat lower for ethanol (3.85 g/gN) than for methanol (4.45 g/gN) in the continuous experiments, while it was considerably higher for ethanol (6.1 g/gN) than for methanol (4.1 g/gN) in pure culture batch cultivations.

Comparative studies on myceliogenic germination of tan sclerotia of Sclerotinia sclerotiorum and Sclerotium rolfsii

1989 ◽  
Vol 67 (5) ◽  
pp. 1395-1401 ◽  
Author(s):  
H. C. Huang ◽  
S. K. Sun
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Room Temperature ◽  
Sclerotium Rolfsii ◽  
Soil Surface ◽  
Time Lapse ◽  
Potato Dextrose Agar ◽  
Damping Off ◽  
Seed Rot ◽  
Myceliogenic Germination ◽  
Exogenous Nutrients

Tan-colored sclerotia of Sclerotium rolfsii and of an aberrant strain of Sclerotinia sclerotiorum that were freshly harvested from 5-week-old cultures on potato dextrose agar or stored at room temperature in paper bags for 4 weeks germinated myceliogenically on moist field soil without exogenous nutrients. A comparative study by time-lapse photomicroscopy revealed similarity in the mode of myceliogenic germination of sclerotia of the two species. The germination appeared to be of the hyphal type in both species and was characterized by the emergence of individual hyphae through the rind. There was no evidence of eruptive type of germination in any of the strains tested. Although several hyphae often emerged through the same spot of the rind, these hyphae emerged singly, and the time-lapse photomicrographs showed no evidence of eruptive germination. While most of the germinated sclerotia of S. rolfsii developed into colonies within 4 days of incubation on moist soil, the development of colonies from germinating sclerotia of S. sclerotiorum appeared to be slow, taking up to 28 days. Results of the inoculation studies showed that mycelia from the germinated sclerotia of S. rolfsii were able to infect and cause seed rot and damping-off of canola and alfalfa, which were planted near the soil surface at a distance of at least 15 mm from the sclerotium, without providing exogenous nutrients.

scholarly journals KHẢ NĂNG KHÁNG NẤM VÀ HẠN CHẾ BỆNH HÉO RŨ GỐC MỐC TRẮNG LẠC (Sclerotium rolfsii) CỦA DUNG DỊCH NANO BẠC

2018 ◽  
Vol 127 (3A) ◽  
Author(s):  
Lê Như Cương ◽  
Nguyễn Thị Nhung ◽  
Nguyễn Thị Diễm
Keyword(s):  
Sclerotium Rolfsii ◽  
Potato Dextrose Agar ◽  
Potato Dextrose Broth

Tóm tắt: Bệnh héo rũ gốc mốc trắng do nấm Sclerotium rolfsii gây ra là một bệnh nguy hiểm trên cây lạc. Để hạn chế bệnh hại, cần áp dụng một hệ thống quản lý tổng hợp bao gồm sử dụng thuốc hóa học, sử dụng các tác nhân phòng trừ sinh học và sử dụng biện pháp canh tác. Trong những năm gần đây, nano bạc đã được nghiên cứu và ứng dụng phòng trừ một số bệnh hại cây trồng. Tuy nhiên, chưa có nhiều nghiên cứu trong hạn chế bệnh héo rũ gốc mốc trắng trên cây lạc. Trong nghiên cứu này, hiệu quả kháng nấm và hạn chế bệnh hại của nano bạc được thực hiện trong điều kiện in vitro và trong điều kiện nhà lưới. Kết quả nghiên cứu cho thấy nano bạc hạn chế nấm S. rolfsii cả trên môi trường đặc (Potato Dextrose Agar – PDA) và môi trường lỏng (Potato Dextrose Broth – PDB). Tuy nhiên, trong môi trường lỏng, nano bạc thể hiện khả năng kháng nấm cao hơn trên môi trường đặc. Trong điều kiện nhà lưới, nano bạc hạn chế tỷ lệ bệnh, chỉ số bệnh và tỷ lệ cây chết đối với bệnh héo rũ gốc mốc trắng trên cây lạc.Keywords: héo rũ gốc mốc trắng, cây lạc, nano bạc, Sclerotium rolfsii

The effects of light and tyrosinase during sclerotium development in Sclerotium rolfsii Sacc.

1977 ◽  
Vol 23 (3) ◽  
pp. 278-287 ◽  
Author(s):  
R. Michael Miller ◽  
Anthony E. Liberta
Keyword(s):  
Laccase Activity ◽  
Red Light ◽  
Sclerotium Rolfsii ◽  
Petri Dish ◽  
Activity Levels ◽  
Stage Of Development ◽  
Sclerotial Formation ◽  
Light Activity ◽  
Temperature Optima

Some effects of light on morphogenesis in Sclerotium rolfsii Sacc. were studied. Physiological competence to visible light developed during the first 120 h after inoculation, with an optimum sensitivity phase between 84 and 96 h that coincided with the leading hyphae reaching the edge of the Petri dish. Although sclerotial initials were produced in dark-grown cultures, light was necessary for the continuation of the developmental and maturation phases of sclerotial morphogenesis. Tyrosinase activity (o-diphenol: oxygen oxidoreductase, EC 1.10.3.1) was detected during sclerotial formation and the pH and temperature optima for this polyphenol oxidase in vitro were about 6.0 and 45 °C respectively. The enzyme was inhibited by cysteine. Similar activity levels of tyrosinase were obtained in blue and 'white' light-grown cultures but in red light activity was comparable with that of dark-grown cultures. Laccase activity was not detected at any stage of development.

scholarly journals Variations In Different Isolates Of Rhizoctonia Solani Based On Temperature And pH

1970 ◽  
Vol 36 (3) ◽  
pp. 389-396 ◽  
Author(s):  
BK Goswami ◽  
MM Rahaman ◽  
AKMA Hoque ◽  
K Bhuiyan ◽  
IH Mian
Keyword(s):  
Growth Factors ◽  
Rhizoctonia Solani ◽  
Radial Growth ◽  
Mycelial Growth ◽  
Potato Dextrose Agar ◽  
Optimum Temperature ◽  
Optimum Ph ◽  
Sclerotial Formation ◽  
Rates Of Growth ◽  
Different Levels

An experiment was conducted to find out variation in isolated Rhizoctonia solani based on radial mycelial growth and sclerotial production. Five isolates of Rhizoctonia solani representing five clusters group were selected and were grown at different levels of temperature and pH on potato dextrose agar (PDA). It was observed that optimum temperature and pH for growth and scierotial production varied among the isolates. The rates of growth and sclerotial formation were not uniform at the same levels of the two growth factors. The maximum mycelial growth of all isolates was found at 30°C. At 35°C, only GAZ-9 and GAZ-18 showed initiation of growth, but the rate was very slow. The optimum temperature for sclerotial production of the isolates GAZ-9, JES- 16, GAZ-18 SYL-26 was 30°C and for the isolate DIN-8 was 25°C. The optimum pH for maximum radial growth was 6 for DIN-8 and 7 for other four isolates. The maximum number of sclerotia was produced by DIN-8, GAZ-9, and SYL-30 at pH 8, 4, and 7, respectively. The optimum pH for sclerotia formation in JES-16 and GAZ-18 was pH 6. Keywords: Rhizoctonia solani; variations; temperature; pH. DOI: http://dx.doi.org/10.3329/bjar.v36i3.9267 BJAR 2011; 36(3): 389-396

scholarly journals Random T-DNA Mutagenesis Identifies a Cu/Zn Superoxide Dismutase Gene as a Virulence Factor of Sclerotinia sclerotiorum

2013 ◽  
Vol 26 (4) ◽  
pp. 431-441 ◽  
Author(s):  
Liangsheng Xu ◽  
Weidong Chen
Keyword(s):  
Oxidative Stress ◽  
Growth Rate ◽  
Superoxide Dismutase ◽  
Sclerotinia Sclerotiorum ◽  
Virulence Factor ◽  
Wild Type ◽  
Expression Levels ◽  
Sclerotial Formation ◽  
Increased Sensitivity ◽  
And Oxidative Stress

Agrobacterium-mediated transformation (AMT) was used to identify potential virulence factors in Sclerotinia sclerotiorum. Screening AMT transformants identified two mutants showing significantly reduced virulence. The mutants showed growth rate, sclerotial formation, and oxalate production similar to that of the wild type. The mutation was due to a single T-DNA insertion at 212 bp downstream of the Cu/Zn superoxide dismutase (SOD) gene (SsSOD1, SS1G_00699). Expression levels of SsSOD1 were significantly increased under oxidative stresses or during plant infection in the wild-type strain but could not be detected in the mutant. SsSOD1 functionally complemented the Cu/Zn SOD gene in a Δsod1 Saccharomyces cerevisiae mutant. The SOD mutant had increased sensitivity to heavy metal toxicity and oxidative stress in culture and reduced ability to detoxify superoxide in infected leaves. The mutant also had reduced expression levels of other known pathogenicity genes such as endo-polygalacturanases sspg1 and sspg3. The functions of SsSOD1 were further confirmed by SsSOD1-deletion mutation. Like the AMT insertion mutant, the SsSOD1-deletion mutant exhibited normal growth rate, sclerotial formation, oxalate production, increased sensitivity to metal and oxidative stress, and reduced virulence. These results suggest that SsSOD1, while not being required for saprophytic growth and completion of the life cycle, plays critical roles in detoxification of reactive oxygen species during host–pathogen interactions and is an important virulence factor of Sclerotinia sclerotiorum.

scholarly journals Growth response of Aspergillus flavus IMS1103 isolated from poultry feed

2016 ◽  
Vol 2 (2) ◽  
pp. 221-228 ◽  
Author(s):  
Monzur Morshed Ahmed ◽  
Md Fakruddin ◽  
Md Nur Hossain ◽  
Khandaker Rayhan Mahbub ◽  
Abhijit Chowdhury
Keyword(s):  
Growth Rate ◽  
Aspergillus Flavus ◽  
Growth Response ◽  
Culture Media ◽  
Agar Medium ◽  
Lag Time ◽  
Potato Dextrose Agar ◽  
Poultry Feed ◽  
Effect Of Temperature ◽  
Temperature Range

Aspergillus flavus strains were isolated from locally available poultry feeds. Effect of temperature, pH and culture media on growth of Aspergillus flavus was studied. Temperature ranged from 4-42°C (4, 10, 20, 25, 30, 37 and 42°C) was examined. Except for 4°C and 10°C, the isolate was able to grow for the whole temperature range. The growth was maximum at 25°C and was influenced with increasing or decreasing of temperature from 42°C to 20°C.The lag time was strongly influenced by the temperature at lower temperature level than at higher temperature range. Effect of pH on growth of Aspergillus flavus was also examined; from comparison of 3 different pH levels, it is concluded that at most temperatures pH 6.5 showed a higher growth rate and as a consequence required a shorter time to achieve maximum colony diameter. No significant variations in the lag time were observed. A natural poultry feed meal agar medium (FMAM) was developed in the laboratory and growth of A. flavus was compared with other 2 synthetic dehydrated media namely; Czapek’sdox Agar (CDA) and potato dextrose Agar (PDA). Poultry feed meal agar medium showed better growth response than Czapek’sdox agar and potato dextrose agar at all conditions. At 25°C and pH 6.5 found optimum for growth of Aspergillus flavus in feed meal agar medium whereas, temperature 30°C and pH 6.5 found optimum for growth for Czapek’sdox agar media and temperature 30°C and pH 6 showed high growth rate on potato dextrose agar. Poultry feed meal media showed high affinity for growth of mycelium and early spore formation than other media examined.Asian J. Med. Biol. Res. June 2016, 2(2): 221-228

scholarly journals Instability of Propiconazole Resistance and Fitness in Monilinia fructicola

2007 ◽  
Vol 97 (4) ◽  
pp. 448-453 ◽  
Author(s):  
K. D. Cox ◽  
P. K. Bryson ◽  
G. Schnabel
Keyword(s):  
Growth Rate ◽  
Cold Storage ◽  
Spore Production ◽  
Potato Dextrose Agar ◽  
Monilinia Fructicola ◽  
Relative Growth ◽  
Germination And Growth ◽  
Time Of Collection ◽  
Demethylation Inhibitor

The fitness and the dynamics of demethylation inhibitor fungicide (DMI) sensitivity in isolates of Monilinia fructicola sensitive (no growth at 0.3 mg/liter propiconazole) and resistant (≥50% relative growth at 0.3 mg/liter propiconazole) to propiconazole were investigated. Overall, there was no considerable compromise in the fitness of resistant isolates compared to sensitive isolates of M. fructicola at the time of collection. Resistant and sensitive isolates differed in their sensitivity to propiconazole (P < 0.001) and incubation period (P = 0.044), but not in latent period, growth rate, spore production, and spore germination frequency (P > 0.05). Consecutive transferring on potato dextrose agar had an impact on conidia production, conidial germination, and growth rate (P < 0.0001). Consecutive transferring also had an impact on propiconazole sensitivity in resistant isolates. In the resistant isolates, sensitivity to propiconazole increased (R2 = 0.960, P = 0.0034) within the first eight transfers. Similarly, sensitivity to propiconazole increased by 273% over the course of 34 months in cold storage in propiconazole-resistant isolates. Our results show that propiconazole resistance is unstable in vitro and that standard subculturing and cold storage procedures impact propiconazole sensitivity of resistant isolates. The instability of propiconazole resistance in M. fructicola may have important implications for disease management in that a reversion to propiconazole sensitivity could potentially occur in the absence of DMI fungicide pressure in the field.

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