The response to salinity of a population of Dactyloctenium aegyptium from a saline habitat in southern Nigeria

1994 ◽  
Vol 10 (2) ◽  
pp. 219-228 ◽  
Author(s):  
A. A. Adu ◽  
A. R. Yeo ◽  
O. T. Okusanya
Keyword(s):  
Sea Water ◽  
Nutrient Deficiency ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Potassium Nitrate ◽  
Inhibitory Effect ◽  
Ion Concentration ◽  
Dactyloctenium Aegyptium ◽  
Sodium And Potassium ◽  
Water Contents

ABSTRACTThe effects of salinity upon the growth, photosynthesis, ion and water contents of a population of Dactyloctenium aegyptium originating from a saline site in Nigeria were investigated. Growth was unaffected by a salinity of 10% artificial sea water, but was reduced by one third in 20% and by two thirds in 30% artificial sea water respectively. Initial adjustment to salinity was due both to increases in the concentrations of sodium and potassium per unit dry weight and to reduced hydration, the latter being the more important at higher salinities. The increase in ion concentration in the cell sap balanced the salinity of the medium at 10% artificial sea water, but was excessive at higher concentrations of sea water. Net photosynthesis was unaffected by 10% artificial sea water but declined at higher salinities. The potassium content of the plants did not fall below 200–250 mM, and the sodium to potassium ratio did not exceed three, even at the highest salinities. Variation in the concentration of nutrients (potassium, nitrate and sulphate) in the medium in the presence of 25% artificial sea water had significant effects upon growth, but these were small in relation to the inhibitory effect of the salinity.The reduction in growth could not be attributed to lack of osmotic adjustment or to nutrient deficiency, and was probably due to ion toxicity within the leaves. The tolerance to reduced hydration, combined with the ability to germinate in saline conditions previously observed, could enable D. aegyptium to establish in a saline soil. The population did not exhibit any halophytic characteristics but did survive with a low growth rate at salinities up to 50% artificial sea water. It is concluded that the species was able to colonize the saline site because of its inherent adaptability, rather than the possession of an ecotype adapted to saline conditions.

scholarly journals THE POTENTIAL USE OF Ca(NO3)2 TO IMPROVE SALINITY TOLERANCE IN DATE PALM (Phoenix dactylifera L.)

2021 ◽  
Vol 52 (2) ◽  
pp. 445-453
Author(s):  
Saleh M. Alturki
Keyword(s):  
Date Palm ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Phoenix Dactylifera ◽  
Inhibitory Effect ◽  
Plant Parts ◽  
Salinity Levels ◽  
Almost All ◽  
Saline Solutions ◽  
The Impact

The study was conducted to investigate the impact of Ca(NO3)2 on  different levels of salt-stress in date palm. Three-years-old date palm plants were subjected to four NaCl levels: 50, 100, 150 and 200 mM. The saline solutions were supplemented with 0, 5, 10 and 20 mM Ca(NO3)2. The combined NaCl/Ca(NO3)2 treatments were conducted over a period of 10 weeks. Control plants were only subjected to the four salinity levels with no Ca (NO3)2 addition. Results showed an inhibitory effect of salinity on almost all plants' parameters under investigation, mainly the accumulation of ions such as N, K, Ca, plant dry weight, chlorophyll and net photosynthesis rate. Addition of Ca (NO3)2 in the solution was more beneficial when added in a moderate concentration (10 mM) compared to lower (5 mM) and higher (20 mM) under all salinity levels. The addition of 10 mM Ca (NO3)2 noticeably enhanced chlorophyll content under 50 mM Na Cl (2.5 mg/100 cm2) and 150 mM NaCl (2 mg/100 cm2). In addition, 10 mM Ca (NO3)2 reduced the accumulation of Na and Cl in plant parts. For instance, in trees subjected to 10 mM Ca (NO3)2, Cl content in leaves and stems under 50 mM Na Cl were 0.23% and 0.65%, respectively. On the other hand, Cl content under 100 mM Na Cl and 200 mM Na Cl were lower compared to their corresponding control treatments. It seems that the use of Ca (NO3)2 had ameliorative effects on salt-stressed date palm plants when used with moderate concentrations.

scholarly journals Studies on Ectocarpus in Culture II. Growth and Nutrition of a Bacteria-Free Culture

1961 ◽  
Vol 41 (2) ◽  
pp. 287-304 ◽  
Author(s):  
G. T. Boalch
Keyword(s):  
Growth Rate ◽  
Sea Water ◽  
Culture Media ◽  
Potassium Phosphate ◽  
Dry Weight ◽  
Maximum Growth ◽  
Potassium Nitrate ◽  
Natural Seawater ◽  
Growth And Nutrition ◽  
Water Media

The growth and nutrition of Ectocarpus confervoides has been studied in bacteria-free cultures. Growth was estimated by dry weights determined under controlled conditions. A method for inoculation of cultures of filamentous algae is described and a table of culture media is given. Following a lag of 5–7 days there was a period of growth, which was not truly exponential, extending over a period of 35 days. Calculation of the relative growth constant for the early stages of growth indicated that the alga doubled its dry weight every 6–7 days. Cultures of Ectocarpus remained viable for over 1 year in the light and for over 100 days in the dark. In natural sea-water media the maximum growth was brought about by the addition of 0·5 mM potassium nitrate and 0·1 mM potassium phosphate. Ferric chloride had no effect on growth but additions of manganese chloride did cause some stimulation. Additions of some complex organic mixtures slightly increased growth but Ectocarpus was unable to grow on a range of organic carbon source in the dark. The optimum salinity at 20° C was somewhat higher than that of natural sea water but was apparently lower at 15° C. The optimum pH was 8·0. Light intensities between 1350 and 16,000 lux had no marked effects on the growth rate but did effect the lag, the optimum for this being 7000 lux. Temperature also had no effect on the growth rate but did effect the lag. The optimum was 15–20° C but there was growth between 10 and 25° C. A considerable range of artificial sea waters, with and without organic additions was investigated, in no case did they give a yield greater than two-thirds that in natural seawater media. These results are discussed in relation to other workers findings.

Ecological significance of net photosynthesis activation by water vapour uptake in Ramalina capitata from rain-protected habitats in central Spain

2002 ◽  
Vol 34 (5) ◽  
pp. 403-413 ◽  
Author(s):  
Ana Pintado ◽  
Leopoldo G. Sancho
Keyword(s):  
Water Content ◽  
Water Vapour ◽  
Liquid Water ◽  
Net Photosynthesis ◽  
Dry Weight ◽  
Central Spain ◽  
Photosynthetic Rates ◽  
Positive Balance ◽  
Water Vapour Uptake ◽  
Water Contents

AbstractThe reactivation of net photosynthesis and dark respiration from water vapour and from liquid water in the lichen Ramalina capitata var. protecta (H. Magn.) Nimis from sheltered habitats in Central Spain was investigated. CO2 gas-exchange response and thallus water content were measured in the laboratory as dry thalli were allowed to equilibrate by water vapour uptake under different relative humidities, and as saturated thalli dried. Water content of thalli from different habitats was also measured in the field during rainfall. The results show that the lichen is very efficient in using water vapour from the air for photosynthesis. Net photosynthetic rates were measured at very low water potentials (up to – 26-9 Megapascal) with water contents of the thalli below 30% dry weight. Maximum net photosynthetic rates measured after water vapour uptake were in some cases similar to those obtained after hydration by liquid water, while respiration rates were always lower after water vapour uptake, indicating a relatively larger activation of the photobiont. Moreover, photosynthetic rates at thallus water contents below 60% dry weight were higher when hydration was achieved through water vapour uptake than with liquid water. Field measurements had shown that this lichen reached water contents through water vapour absorption of 40% dry weight that would allow a positive balance of CO2 uptake. Possible ecological implications of differences in photosynthetic activation depending on the water source are discussed in terms of the carbon gain under natural conditions of this ombrophobous lichen.

scholarly journals The Hydrogen-ion Concentration of Sea Water

Nature ◽  
1923 ◽  
Vol 111 (2778) ◽  
pp. 132-133
Author(s):  
J. J.
Keyword(s):  
Sea Water ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Hydrogen Ion Concentration

scholarly journals Effect of mint (Mentha piperita L.) and caraway (Carum carvi L.) on the growth of some toxigenic aspergillus species and aflatoxin B1 production

2009 ◽  
pp. 131-139 ◽  
Author(s):  
Marija Skrinjar ◽  
Anamarija Mandic ◽  
Aleksandra Misan ◽  
Marijana Sakac ◽  
Ljubisa Saric ◽  
...  
Keyword(s):  
Aflatoxin B1 ◽  
Dry Weight ◽  
Inhibitory Effect ◽  
Aspergillus Species ◽  
Mentha Piperita ◽  
Ph Values ◽  
Carum Carvi ◽  
The Media ◽  
Total Dry Weight ◽  
Poor Concentration

An inhibitory effect of various concentrations (0.0, 0.5, 1.0, 1.5 and 2,0%) of mint (Mentha piperita L.) and caraway (Carvum carvi L.) on the growth of A. fumigatus, A. flavus and A. ochraceus was examined during 10 days of cultivation in YES medium at temperature of 25?C. Mint showed stronger inhibitory effect than caraway. Total dry weight (g/l) after 10 days of the growth of A. fumigatus in YES medium with 0.5% of mint decreased by about 95%, A. flavus by 97% and A. ochraceus by about 82%. Addition of higher concentrations of mint (1.0, 1.5 and 2.0%) reduced the growth of all tested species. It was poor and hardly visible. pH values of the media increased with the increase of mint concentrations. A. fumigatus showed the highest sensitivity towards caraway and A. flavus the lowest. Total dry weight (g/l) after 10 days of growth of A. fumigatus in medium with 0.5% of caraway decreased by about 72% in comparison to the control. In media with higher concentrations of caraway, its growth was found to be very poor. Concentration of 1.0% of caraway reduced A. flavus growth by 15% and of 1.5% by 92%, in regard to the control. In medium with 2.0% of caraway the growth of A. flavus was observed as poor and hardly visible. The growth of A. ochraceus in medium with 0.5% of caraway decreased by about 85% comparing with control and further decrease was noticed by the increase of concentrations. In medium with 1.5% of caraway a reduction of about 95% of growth was found and under 2.0% of caraway it was poor. pH of the media also increased with the increase of caraway concentrations. Applied concentrations of mint and caraway inhibited completely the production of AB1 by A. flavus.

scholarly journals Antibacterial Potentials of some Toothpaste Products against some Oral Bacterial Isolates

2021 ◽  
Vol 24 (2) ◽  
Author(s):  
Bernard Oluwapelumi Oluboyo ◽  
Maihankali J Charles ◽  
Richard Akele ◽  
Funmilayo Akinseye ◽  
Adeola Oluboyo
Keyword(s):  
Benzyl Alcohol ◽  
Sodium Fluoride ◽  
Zinc Sulphate ◽  
Potassium Nitrate ◽  
Inhibitory Effect ◽  
Oral Microbiome ◽  
Diffusion Method ◽  
E Coli ◽  
Test Microorganism ◽  
Bactericidal Effects

Objetive: Manufacturers of toothpastes claim that their products are active against oral microbiome capable of causing tooth decay. The objective of this study was to investigate the manufacturers’ claim using some of the toothpaste products sold in Ado-Ekiti, Nigeria. Material and methods: The antibacterial potentials of five commercialized toothpaste products (designated sodium fluoride-zinc sulphate, benzyl alcohol-sodium fluorophosphate, sodium fluoride-eugenol, sodium fluoridesodium laurylsulfate and sodium fluoridepotassium nitrate) were tested against six oral isolates of dental caries and periodontal origin – Staphylococcus aureus, Streptococcus mitis, Streptococcus salivarius, Streptococcus pyogenes and Pseudomonas aeruginosa. The antimicrobial potentials were evaluated using modified agar well diffusion method. Various dilutions of the toothpaste products from 1:1 to 1:16 were tested against each test microorganism. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the toothpastes were determined. Results: sodium fluoride-zinc sulphate, benzyl alcoholsodium fluorophosphate and sodium fluorideeugenol toothpastes showed inhibitory effects on S. aureus, S. mitis and S. salivarius. Sodium fluoride-sodium laurylsulfate and sodium fluoride-potassium nitrate toothpastes showed no inhibitory effect on the organisms except S. pyogenes. Only sodium fluoride-potassium nitrate toothpaste inhibited E. coli while none of the toothpastes inhibited P. aeruginosa. The MIC and MBC of sodium fluoride-zinc sulphate, benzyl alcohol-sodium fluorophosphate, and sodium fluoride-eugenol toothpastes showed bacteriostatic and bactericidal effects on the organisms. Sodium fluoride-zinc sulphate, benzyl alcohol-sodium fluorophosphate, and sodium fluoride-eugenol toothpastes showed comparable effects on S. aureus, S. mitis and S. salivarius. Sodium fluoride-eugenol toothpaste was strongest against S. mitis, benzyl alcoholsodium fluorophosphates toothpaste was strongest against S. pyogenes, sodium fluoridezinc sulphate toothpaste was strongest against S. salivarius and only sodium fluoride-potassium nitrate toothpaste inhibited E. coli. Conclusion: The manufacturer’s claim is upheld by this study for sodium fluoride-zinc sulphate, benzyl alcohol-sodium fluorophosphate and sodium fluoride-eugenol toothpastes. However, sodium fluoride-sodium laurylsulfate and sodium fluoride-potassium nitrate toothpastes showed limited inhibitory potentials.     Keywords Antibacterial; Caries; Oral isolates; Periodontitis; Toothpastes.

scholarly journals ALLELOPATHIC POTENTIAL OF WEED SPEICES AGERATUM CONYZOIDES L. AND CLEOME VISCOSA L. ON GERMINATION AND GROWTH OF SESAMUM INDICUM L

2015 ◽  
Vol 2 (2) ◽  
pp. 114-117
Author(s):  
Anbarasan R ◽  
Prabhakaran J
Keyword(s):  
Growth Parameters ◽  
Dry Weight ◽  
Inhibitory Effect ◽  
Germination Percentage ◽  
Sesamum Indicum ◽  
Weed Species ◽  
Ageratum Conyzoides ◽  
Allelopathic Potential ◽  
Germination And Growth ◽  
Cleome Viscosa

Various concentrations (5%, 10%, 15% and 20%) of aqueous extracts prepared from two weed species namely Ageratum conyzoides L. and Cleome viscosa L. and used for the present experiments to determine their allelopathic potential on growth and developmental changes on sesame (Sesamum indicum L.). The weed extracts showed an inhibitory effect on germination percentage, root and shoot growth, and fresh and dry weight of sesame seedlings. The extracts of A.conyzoides had more inhibitory effect at 20%concentration,than that of C.viscosa on growth parameters of sesame.

scholarly journals Anti-fungal activities of constituents from Uvaria scheffleri and Artabotrys brachypetalus

2006 ◽  
Vol 51 (1) ◽  
pp. 79-86 ◽  
Author(s):  
A.C. Odebode ◽  
S.A. Jonker ◽  
C.C. Joseph ◽  
S.W. Wachira
Keyword(s):  
Fusarium Solani ◽  
Radial Growth ◽  
Fungal Pathogens ◽  
Dry Weight ◽  
Stem Bark ◽  
Inhibitory Effect ◽  
In Vitro Bioassay ◽  
Botryodiplodia Theobromae ◽  
Anti Fungal

The anti-fungal activity of schefflone, a mixture of dimmer, 3,5 dimethoxy carvacrol and annonaceous acetogenin, extracted from stem-bark and root of Uvaria scheffleri and Artabotrys bruchypetalus against Fusarium solani, Botryodiplodia theobromae, Asperillus niger and Aspergillus flavus was determined. An in-vitro bioassay showed that the minimum inhibitory effect of the compounds to the fungal pathogens occurred at 200 ppm in both radial growth and mycelia dry weight measurements. Acetogenin from A brachypetalus had a very strong anti-fungal effect on all the test fungi. The effects of the compounds were more pronounced on F solani than on the other. The bioassay methods also play a significant role in the sensitivity of the samples on the pathogens. .

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