scholarly journals Morphological and cultural studies of Septoria vignicola

2014 ◽  
Vol 19 (1) ◽  
pp. 83-89
Author(s):  
R. D. Rawal ◽  
H. S. Sohi

Pycnidial formation starts six days after inoculation. These arę globose, dark and range between 59.28-109.20 μm in diameier. The pycnidial wall is composed of 2- 3 layers of brown cells. The pycnidiospores ooze 8 days after inoculation. They are filiform, straight to curved, hyaline, septate with 2-4 septa, ends pointed or round and 21.84-68.64 x 1.25-2.15 μm. Mycelial growth was most profuse on Czapek Dox's agar medium, whereas maximum sporulation took place on Coon's, Sabauraud's and Potato dextrose agar media. The fungus could grow over a wide range of temperature from 12- 36°C (optimum: 24 ± l°C) and showed no growth at 40°C or above. Pycnidial formation occurred at 16- 28°C with a maximum at 24 ± l°C. Out of seven carbon sources tested, sorbose was the best for growth and sporulation of <i>Septoria vignicola</i> whereas maltose was a poor source for sporulation. The fungus responded very well to the supply of carbon in culture media as no growth of the fungus could be observed when the carbon supply was with held. Aspartic acid supported optimum growth among all the organic sources tried, whereas among inorganic sources potassium nitrate was the best, last growth observed on ammonium nitrate.

2001 ◽  
Vol 58 (3) ◽  
pp. 613-616 ◽  
Author(s):  
Sideney Becker Onofre ◽  
Cindia Mara Miniuk ◽  
Neiva Monteiro de Barros ◽  
João Lúcio Azevedo

Entomopathogenic fungi from the genus Metarhizium are largely used for the biological control of agricultural pests by conidia spreading on the field. Although conidia production is well studied in M. anisopliae, only few research studies were done in M. flavoviride. The present work was carried out alming to evaluate the Mycelial growth and sporulation of the entomopathogenic fungus Metarhizium flavoviride var. flavoviride growing at 27 ± 2°C on Potato-dextrose-agar (PDA), Czapek-agar (CZP) and a complete agar medium (CM) under three lighting regimes, (continuous illumination, light/dark cycle and an black light/dark cycle) were investigated. A completely randomized 3 × 3 (culture media × lighting regime) factorial design with four replicates was used. The best mycelial growth and sporulation occurred on the PDA and CM media under continuous illumination (P <= 0,05).


2014 ◽  
Vol 42 (2) ◽  
pp. 265-272 ◽  
Author(s):  
Fakhruddin Ali Ahmed ◽  
Nazmul Alam ◽  
Abul Khair

Eight commercial okra cultivars were evaluated to determine the magnitude of incidence of Corynespora cassiicola (Berk. & Curt.) Wei. Maximum and significant incidence of C. cassiicola was 14.86 in the cultivar BARI 1. In rest of the cultivars, the occurrence of this fungus was very poor to nil. Corynespora cassiicola appeared to be a minor pathogen for okra. Effects of temperature, pH and culture media on growth and sporulation of the fungus were investigated. Potato dextrose agar medium was found to be the most suitable for optimum growth and sporulation of this fungus at pH 7 and 25ºC. The conidial length significantly varied with the changes of pH. The correlation between pH and conidial length was found negative and highly significant. DOI: http://dx.doi.org/10.3329/bjb.v42i2.18028 Bangladesh J. Bot. 42(2): 265-272, 2013 (December)


2012 ◽  
Vol 60 (2) ◽  
pp. 109-129 ◽  
Author(s):  
I. Csöndes

Macrophomina phaseolina (Tassi) Goidanich can cause serious yield losses in several plant species. Investigations were made on the colony morphology of fifty Macrophomina phaseolina isolates from Hungary, one from Spain and two from Serbia on six different culture media to detect differences between the isolates. The fungus exhibited the most intensive growth on maize-flour agar, followed by the Sabouraud-glucose, maltextract, potato-dextrose, Czapek-Dox and watery agar media. Investigations on the macromorphology of the isolates revealed different extents of aerial mycelia formation and differences in the zonal structure of microsclerotial formation on the individual media. One isolate (Mp 38) turned the Sabouraud-glucose agar medium pale pink. Investigations on the micromorphology of the cultures showed that the isolates also varied with respect to microsclerotial characters (size, shape and production of microsclerotia). The microsclerotia of this fungal pathogen had the greatest diameter (averaging 135.31 μm) on Sabouraud-glucose agar medium. This study was the first in Hungary to prove that Macrophomina phaseolina could be grown on nutrient-deficient watery agar, suggesting that it can tolerate a wide range of ecological circumstances.


Author(s):  
Md Iqbal Ahmad ◽  
Avijit Kumar Biswas ◽  
Mst Sabiha Sultana ◽  
Bidhan Chandro Sarker ◽  
Chhoa Mondal

Sclerotium oryzae causing sheath rot of rice, is one of the most important pathogen causing heavy crop losses in all the major rice growing areas of the world, including Bangladesh. The growth and reproduction of this soil borne pathogen depends on growing media and abiotic factors. Therefore, to evaluate the effect of different culture media and pH on mycelial radial growth of S. oryzae, the experiment was conducted in the Plant Pathology Laboratory of Agrotechnology Discipline, Khulna University, Khulna, Bangladesh. Performance of different media, carbon source and nitrogen source on radial mycelial growth was differed significantly. The maximum mycelial radial growth was observed on rice stem agar medium (70.40 mm) and minimum mycelial radial growth was recorded on cornmeal agar medium (50.60 mm). Considering carbon source, the maximum radial mycelial growth was found in glucose (66.40 mm) amended medium and no statistical differences were observed among sucrose, starch and Czapek dox agar containing medium. Based on nitrogen source, maximum radial mycelial growth was found in peptone medium (69.40 mm) but no statistical differences were exposed between Potassium nitrate (KNO3) and Sodium nitrate (NaNO3). pH- 6 played a vital role in radial mycelial growth (73.75 mm) of S. oryzae. South Asian J. Agric., 7(1&2): 67-72


2018 ◽  
Vol 14 (3) ◽  
pp. 240
Author(s):  
Odu C.E. ◽  
Ogbonna C.I.C. ◽  
Bukbuk D. ◽  
Chukwu O.O.C. ◽  
Yerima I. ◽  
...  

Studies were carried out on the abilities of four aquatic phycomycetes species isolated from crude oil polluted marine , brackish and fresh water environments in Nigeria to utilize refined Petroleum and Petroleum products as sole sources of carbon. The said species of fungi included Brevilegnia indica, Protoachyla paradoxa, Saprolegnia bhargavi and Thraustotheca clavata. They were grown on fungal culture media which contained mineral salts solution, refined petroleum, kerosene and diesel as sole sources of carbon and agar as a solidifying agent. Two concentrations of each of the resulting oil agar media were used vis 1% and 2%. The resultant medium was then used to culture each of the test fungi in triplicates. The resultant culture plates were then incubated at 25 OC and left for daily observation. The test fungi that grew on each medium were observed for their abilities to emulsify the refined petroleum or its products (diesel and kerosene). Control experiments were also set up using Malt Extract Agar medium. Brevilegnia indica grew on 1% petroleum and diesel growth media but did not grow on kerosene medium. Protoachyla paradoxa grew minimally on diesel medium at 1% and 2% compositions. Saprolegnia bhargavi did not grow on the petroleum agar medium or petroleum products media. Thraustotheca clavata grew minimally on the kerosene medium at both 1% and 2% compositions. The four test fungi emulsified the diesel agar medium at both 1% and 2% compositions. Brevilegnia indica emulsified only petrol at 1% while Non of the isolates emulsified the kerosene medium at both 1% and 2% compositions. Oil globules were also observed in the vegetative hyphae of the test fungi which grew on the experimental culture media. This means that such fungi either degraded or accumulated the petrol or petroleum products in their systems.


2015 ◽  
Vol 23 (4) ◽  
pp. 461-479 ◽  
Author(s):  
Robie W. Macdonald ◽  
Zou Zou A. Kuzyk ◽  
Sophia C. Johannessen

The sediments of the pan-Arctic shelves contribute an important component to the Arctic Ocean ecosystem by providing a habitat for biota (benthos), a repository for organic and inorganic non-conservative substances entering or produced within the ocean, a reactor and source of transformed substances back to the water column, and a mechanism of burial. Sediments interact with ice, ocean, and the surrounding land over a wide range of space and time scales. We discuss the vulnerability of shelf sediment to changes in (i) organic carbon sources, (ii) pathways of sediment and organic carbon supply, and (iii) physical and biogeochemical alteration (diagenesis). Sedimentary environments of the shelves and basins are likely to exhibit a wide variance in their response to global change because of their wide variation in sediment sources, processes, and metabolic conditions. In particular, the Chukchi and Barents shelves are dominated by inflowing waters from oceans to the south, whereas the interior shelves are more closely tied to terrigenous sources due to river inflow and coastal erosion.


2019 ◽  
Vol 41 (4) ◽  
pp. 416-422
Author(s):  
Ricardo Borges Pereira ◽  
Tiago B. Torres ◽  
Patrícia Pereira da Silva ◽  
Gilvaine C. Lucas ◽  
Jadir Borges Pinheiro ◽  
...  

Abstract: This study aimed at evaluating the method of inoculation of carrot seeds in a potato-dextrose-agar medium (PDA) added of mannitol. Alternaria radicina was the fungus chosen to test such methodology. The osmosis-controlling agent was employed to obtain the osmotic potentials of 0.6 MPa, 0.8 MPa, 1.0 MPa and 1.2 MPa. In comparison with the control treatment, no significant mycelial growth inhibition was noticed at any of the osmotic potentials considered. The seeds were distributed over the fungal colonies for infection, where they remained for 48, 72, 96, 120 and 144 hours, at the osmotic potentials of 0.0 MPa (control), 0.6 MPa, 0.8 MPa, 1.0 MPa and 1.2 MPa, respectively. Tests of germination, sanitization and emergence were performed to evaluate the effects of colonization. Regarding the germination, the different osmotic potentials resulted in similar percentages of abnormal seedlings and dead seeds. As for the sanitization testing, higher infection rates were observed at the osmotic potentials of 1.0 MPa and 1.2 MPa. The lowest percentage of emergence was found at -1.2 MPa, therefore suggesting that this osmotic potential (produced with mannitol) might be used for infecting carrot seeds for research purposes.


2021 ◽  
Vol 11 (6) ◽  
pp. 14278-14289

The use of plastics, replacing materials such as paper and glass, has become a staple of modern society. A possible alternative is the production of biopolymers, in which case polyhydroxyalkanoates (PHAs) tend to be the most studied class. Among the PHAs, poly(3-hydroxybutyrate) (P(3HB)) is one of the most studied. Bacillus megaterium can utilize a wide range of carbon sources to produce P(3HB) and display high resistance to osmotic pressure and temperature. There are few studies regarding the viability of confectionery wastewater (CWW) and rice parboiling water (RPW) in PHA production; however, data suggests they might be successfully used as culture media for microorganisms. Cultures of B. megaterium were conducted under a 22-factorial design of experiments with different agitation and airflow conditions using mineral medium added with CWW and RPW. Under maximized conditions, it was possible to obtain 7.55 g/L of dry cell biomass, with 50.1% P(3HB) content (3.78 g/L). Kinetic parameters of the maximized culture were also assessed, with the highest productivity (0.146 g/L·h) being found after 20 h of culture. Results found in the tests indicate that CWW and RPW can be used as culture media in P(3HB) production; however further studies are necessary to fully optimize the process, as well as to find alternatives to reduce the amount of residual total organic carbon (TOC) still present in the cultures.


2016 ◽  
Vol 2 (2) ◽  
pp. 221-228 ◽  
Author(s):  
Monzur Morshed Ahmed ◽  
Md Fakruddin ◽  
Md Nur Hossain ◽  
Khandaker Rayhan Mahbub ◽  
Abhijit Chowdhury

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


1972 ◽  
Vol 50 (3) ◽  
pp. 683-685
Author(s):  
R. V. Clark

Four isolates of C. sativus were able to use a number of carbon sources to varying degrees with little evidence of a differential growth response by the isolates. With most carbon sources the response was different when growth on liquid media was compared with that on agar media. Dextrin and L-sorbose were exceptions as dextrin supported good growth with both types and L-sorbose poor with both. Lactose supported the best mycelial growth on liquid media and dextrin the best radial growth and sporulation on agar media when compared with sucrose.


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