Interactive Effects Of Salinity Research Articles

Agar Production from Gracilariopsis heteroclada (Gracilariales, Rhodophyta) Grown at Different Salinity Levels

Gracilariopsis heteroclada grown in fiber glass tanks at four salinity levels was treated with three diferent concen- trations of aqueous NaOH. Yield, gel strength, gelling and melting temperatures of the extracted agar were determined. Plants grown at salinities of 24 and 32‰ and treated with 3% NaOH produced the strongest gel (850 g cm −2 ) and weakest gel (300 g cm −2 ), respectively. Statistically significant differences in gel strength, dynamic gelling and melting temperatures were observed between the various treatments. The interactive effect of salinity and NaOH was significant in gel strength, gelling and melting temperatures of the gel from G. heteroclada

Interactive effects of salinity and adult extract upon settlement of the estuarine barnacle Balanus improvisus (Darwin, 1854)

Balanus improvisus (Darwin, 1854) is distributed in mesohaline regions of estuaries worldwide. In Chesapeake Bay, USA, it occurs intermediately along a horizontal salinity gradient between two congeners, oligohaline B. subalbidus (Henry, 1973) and the more polyhaline B. eburneus (Gould, 1841). Laboratory reared cyprids of B. improvisus were exposed to slate substrata treated or untreated with conspecific settlement factor as salinity was varied. Peak settlement occurred at salinities of 10 and 15ℵ on treated substrata, reflecting an interactive effect of these two parameters. Settlement on untreated substrata was low and showed no salinity pattern. Cyprids of B. improvisus settled in significantly greater numbers on intrathan on interspecific settlement factor adsorbed to slate, and they settled in lowest numbers on settlement factor from B. eburneus compared to B. subalbidus. In addition, surface effects upon settlement were less obvious as age of cyprids increased.

Interactive effects of salinity and ammonium/nitrate ratio on growth and chemical composition of melon plants

Abstract The response of melon plants (Cucumis melo L. cv Galia) to different ratios of NH4‐N/(NH4+NO3)‐N (0, 0.15, 0.3 and 0.6) in saline (9 dS/m) and nonsaline (1.5 ds/m) nutrient solutions (in which the total N level was 5 mmol l‐1 ) was studied using an aerohydroponic system in a greenhouse. The total production of dry matter and the concentration of macronutrients and other elements in plant shoot and root tissue were determined 68 days after transplanting. Dry matter production was not significantly affected by the NH4/N03 ratio but the following general trend of NH4. effect on crop yield cannot be ignored. In nonsaline solutions the presence of a relatively low proportion (0.15) of NH4‐N enhanced the yield of shoot dry matter, whereas under saline conditions the presence of NH4 exerted a negative effect on plant growth. Ammonium nutrition tended to increase the level of total N in plant tissue. Increasing NH4/NO3 ratio (decreasing NO3 level) resulted in higher Na and Cl and lower Ca, K and NO3 leve...

Response of seeds ofLupinus termis andVicia faba to the interactive effect of salinity and ascorbic acid or pyridoxine

The interactive effect of salinity and presoaking in ascorbic acid or phyridoxine on germination, seedling growth, and some relevant metabolic changes ofLupinus termis andVicia faba seeds were studied. Germination studies indicated that broad bean tolerated NaCl salinity up to 240mM NaCl and lupin to 200mM NaCl. The lengths of roots and shoots and their water content, as well as dry matter yield, remained more or less unchanged up to the level of 80mM NaCl.

Spatial and environmental components of evolutionary change: interactive effects of salinity and temperature onFucus vesiculosus as an example

Intertidal algae experience aerial temperatures as well as those of ambient seawater and, during their periods of emergence, are subject to considerable variation in salinity. The eastern Atlantic distribution ofFucus vesiculosus L. (Phaeophyta) lies within the 5° and 20° August isotherms. Experiments indicate that this plant can survive temperatures above and below these at normal salinity (34‰). However, at extreme temperatures it is evidently much more susceptible to saline changes than at those of the limiting isotherms. Thus the temperature limits for surviving acute saline change appear to give a better biogeographical fit than temperature alone. Nevertheless, the presence ofF. vesiculosus in estuaries at or near both geographical limits is inconsistent with the experimental results obtained from British plants. Some population divergence may therefore have occurred.

Interactive effects of salinity and nitrogen on growth and yield of tomato plants

Tomato (Lycopersicon esculentum var. VF 145) plants were grown with Typic Xerofluvents soil in a greenhouse irrigated with recycled nutrient solutions having increasing levels of N and salinity. Positive response of plants to increasing levels of N was obtained at the lowest initial salinity level of 1 dS/m (dS/m=mmho/cm, referenced at 25°C). At the higher initial salinity levels of 5 and 9 dS/m, increasing N was ineffective in counteracting adverse effects on growth and yield caused by the presence of enhanced salt concentrations of the nutrient solution. Total N uptake was linearly correlated with the total water uptake and was severely suppressed by impaired growth associated with the two higher initial salinity levels, irrespective of N levels. The effect of salinity on leaf N concentrations changed over time. Leaf Cl and P concentrations indicated a possible suppressing effect of Cl on P uptake into plant tops.

Interactive effects of salinity, temperature and polycyclic aromatic hydrocarbons on the survival and development rate of larvae of the mud crabRhithropanopeus harrisii

Zoeae of the mud crabRhithropanopeus harrisii (Gould) were exposed continuously throughout larval development to factorial combinations of salinity, temperature and specific aromatic hydrocarbon concentrations. Salinities and temperatures were 5, 15, or 25‰ and 20°, 25°, or 30°C, respectively. Either phenanthrene or naphthalene was tested separately at respective concentrations of 0, 100, 150 or 200 ppb and 0, 125, 250 or 500 ppb. Phenanthrene was much more toxic than naphthalene. Naphthalene was not acutely toxic at any physical factor combination-naphthalene concentration tested. Both compounds caused the highest mortality at low salinities. The time course of mortality due to phenanthrene exposure showed that ecdysis between the first and second zoeal stage was the most sensitive period for the larvae exposed to aqueous hydrocarbons. Phenanthrene-exposed larvae had a decreased development rate, but the naphthalene-exposed larvae developed faster than the controls.

Interactive effects of salinity, temperature and chronic exposure to oil on the survival and developmental rate of embryos of the estuarine killifishFundulus heteroclitus

The combined effect of salinity, temperature and chronic exposure to water-soluble fractions (WSF) of a No. 2 fuel oil on the survival and development rate of embryos ofFundulus heteroclitus Walbaum are described. The embryos were exposed at 3 salinities (10, 20, 30‰ S) and 3 temperatures (20°, 25°, 30°C) to 3 different oil concentrations (15, 20, 25% WSF, equivalent to approx 0.28, 0.38 and 0.47 ppm total naphthalenes) and to one control without oil. The results were analyzed by responsesurface methodology. The lowest oil concentration was only mildly toxic to embryos under optimal salinity/temperature conditions, while the highest was extremely toxic in all factor combinations. Under optimal conditions, only the highest oil concentration resulted in more than 50% mortality. Under suboptimal conditions, especially high and low temperatures, all 3 oil concentrations caused greater than 50% mortality. The interactive effect of salinity and temperature on survival was greatest at the lowest oil concentration. Temperature had a marked effect and salinity only a slight effect on the developmental rate of the embryos. Exposure to the low oil concentration tended to increase the temperature sensitivity of developmental duration slightly. Generally, exposure to oil decreased the time interval between fertilization and hatching.

Interactive Effect of Salinity and Phosphorus on Sesame

AbstractA solution culture experiment was conducted with a short‐season sesame [Sesamum indicum L. (Selection 333)] to observe interactive effects of osmotic potential (−0.4, −1.4, −2.4, and −4.4 bars NaCl added to a complete nutrient solution), and P concentration (0.5, 5, 25, and 50 mg P/liter) on water relations, mineral nutrition, and yield characteristics. Salinity reduced yields linearly with a 50% decrease in pod yield at an osmotic potential of approximately −2.7 bars. Increasing P concentrations increased yields only at low salinity levels; at higher salinity levels, yields decreased progressively as P increased. Salt tolerance was reduced by the higher P additions.A multiple regression equation for pod yield as a function of salinity and P in combination was developed (R2 = 0.76). Leaf water potential at the early flowering stage decreased with pod yield as salinity and P concentrations increased. Leaf NO3 concentrations decreased as salinity increased.

Interactive Effects of Salinity and Phosphorus Nutrition of the Concentrations of Phosphate and Phosphate Esters in Mature Photosynthesizing Corn Leaves

The effects of salinity on corn plants (Zea mays L.) are influenced by the concentration of nutrient orthophosphate. Salinity (-2 bars each of NaCl and CaCl(2)) was more injurious in combination with a high concentration of orthophosphate (2 mm) (that gave optimum yields in the absence of salinity) than it was with a lower concentration (0.1 mm). With 2 mm orthophosphate, salinity seemed to damage the plant mechanisms that normally regulate the internal concentration of orthophosphate resulting in excessive accumulation and P toxicity. On the other hand, with 0.1 mm orthophosphate, salinity decreased orthophosphate concentration in mature leaves. This effect was paralleled by decreases in the concentration of adenosine 5'-triphosphate and in the energy charge of the adenylate system, indicating an orthophosphate deficit. Even so, plants survived salinity better under these conditions than in the presence of 2 mm orthophosphate. The data indicated that salinity affected the phosphorylated state of the adenine nucleotides only indirectly through its effect on the concentration of orthophosphate in the cells.Salinity, especially in the presence of 2 mm orthophosphate, resulted in an increase in the concentrations of sugar phosphates in mature photosynthesizing leaves, suggesting that translocation rather than photosynthesis was a limiting process. Decreased translocation could be a secondary effect of decreased growth. However, a decreased translocation rate could cause decreased growth by limiting the supply of essential metabolites reaching growing tissues.

Interactive effect of salinity, SAR and boron on the germination and growth of seedlings of some paddy (Oryza sativa) varieties

Germination of paddy varieties was significantly decreased with increasing levels of boron (0–100 ppm) with a maximum of 34 per cent. Amongst the treatments of boron (0.5–4.5 ppm): salinity (15–60 mc/l) and SAR (10–50), only the effect of salinity was significant, The interaction of boron × SAR, boron × salinity and salinity × SAR was insignificant in almost all the varieties. Varietal differences in germination and growth of seedlings were observed in relation to salt and boron tolerance. Boron upto 40 ppm did not affect the germination of paddy seeds but growth of seedlings was inhibited above 5 ppm.

Interactive Effects of Salinity and Ozone on Growth and Yield of Garden Beet

AbstractThe interactive effects of root media salinity and ambient ozone on injury, growth, and yield of garden beets (Beta vulgaris L.) were determined under controlled environmental conditions. Plants were grown in nonsaline and saline nutrient solution cultures having osmotic potentials of −0.4, −4.4, and −8.4 bars, respectively, and were exposed 5 weeks to 0.20 ppm ozone for 0 to 3 hours/day.Growth of the nonsaline beet plants were not significantly affected by 0.20 ppm ozone until exposure times exceeded 1 hour/day, although foliar injury in the form of a reddish‐purple stipple had developed on mature leaves. Longer ozone exposures produced severe leaf necrosis and reduced the growth of tops and storage and fibrous roots as much as 50, 40, and 67%, respectively. In contrast, foliar ozone injury on plants grown in saline media developed more slowly and the growth of both tops and roots were relatively unaffected by ozone exposures of up to 3 hours/day. Some reduction in yield of storage roots did occur at −4.4 bars osmotic potential when plants were exposed to ozone for 3 hours/day. However, the beneficial effect of salinity in reducing ozone damage was offset by the suppressive effect of salinity on the yield of the storage root. Dry weights of the storage root were reduced nearly 25% at −4.4 bars osmotic potential.

Plant Growth Suppression on Saline Media: Interactions with Light

Interactive effects of salinity and light on plant growth were studied with intact bean seedlings (Phaseolus vulgaris L.) and with excised cotyledonary leaves of radish (Raphanus sativus L.) cultured on control and saline (NaCl) media in the dark and under a range of light intensities. In both cases, excess NaCl had very little effect on heterotrophic growth in the dark; it had an unexpected stimulating effect on growth in low-intensity light and a suppressive effect only at moderately high light intensities. Excess NaCl was particularly effective in suppressing growth processes requiring high-energy light, for example, leaf expansion and the accompanying net synthesis of nucleic acid and protein. Microscopic examination and analysis of chloroplasts of salt-stunted bean and pea (Pisum sativum L) plants indicated a suppression of chloroplast development.

Interactive Effects of Salinity and Atmospheric Humidity on the Growth of Bean and Cotton Plants

The hypothesis that a large part of the reduction in plant growth on saline media is the result of the combined suppressing action of salinity and transpiration on plant water potential was tested by comparing the effect of salinity on plant growth under conditions of low and high atmospheric humidity. Phaseolus vulgaris L. and Gossypium hirsutum L. were grown on subirrigated sand cultures under controlled conditions. Control cultures were irrigated with a complete base nutrient, saline cultures with base nutrient containing 72 meq NaCl per liter. The shoots were exposed continuously from the early seedling stage to either dry or humid air. As predicted by the hypothesis, high humidity consistently relieved the suppressive effect of salinity, almost completely in the case of cotton, without greatly altering the ion content of the tissues on a dry-weight basis.