Salinity tolerances of three succulent halophytes (Tecticornia spp.) differentially distributed along a salinity gradient

2016 ◽  
Vol 43 (8) ◽  
pp. 739 ◽  
Author(s):  
Louis Moir-Barnetson ◽  
Erik J. Veneklaas ◽  
Timothy D. Colmer
Keyword(s):  
Growth Rates ◽  
Shoot Growth ◽  
High Salinity ◽  
Salt Lake ◽  
Salinity Gradient ◽  
Saline Soils ◽  
Low Salinity ◽  
Substrate Limitation ◽  
Extreme Salinity ◽  
Osmotic Potentials

We evaluated tolerances to salinity (10–2000 mM NaCl) in three halophytic succulent Tecticornia species that are differentially distributed along a salinity gradient at an ephemeral salt lake. The three species showed similar relative shoot and root growth rates at 10–1200 mM NaCl; at 2000 mM NaCl, T. indica subsp. bidens (Nees) K.A.Sheph and P.G.Wilson died, but T. medusa (K.A.Sheph and S.J.van Leeuwen) and T. auriculata (P.G.Wilson) K.A.Sheph and P.G.Wilson survived but showed highly diminished growth rates and were at incipient water stress. The mechanisms of salinity tolerance did not differ among the three species and involved the osmotic adjustment of succulent shoot tissues by the accumulation of Na+, Cl– and the compatible solute glycinebetaine, and the maintenance of high net K+ to Na+ selectivity to the shoot. Growth at extreme salinity was presumably limited by the capacity for vacuolar Na+ and Cl– uptake to provide sufficiently low tissue osmotic potentials for turgor-driven growth. Tissue sugar concentrations were not reduced at high salinity, suggesting that declines in growth would not have been caused by inadequate photosynthesis and substrate limitation compared with plants at low salinity. Equable salt tolerance among the three species up to 1200 mM NaCl means that other factors are likely to contribute to species composition at sites with salinities below this level. The lower NaCl tolerance threshold for survival in T. indica suggests that this species would be competitively inferior to T. medusa and T. auriculata in extremely saline soils.

Isolation and identification of IAA producing endosymbiotic bacteria from Gracillaria corticata (J. Agardh)

2016 ◽  
Vol 5 (12) ◽  
pp. 5179
Author(s):  
Ilahi Shaik* ◽  
P. Janakiram ◽  
Sujatha L. ◽  
Sushma Chandra
Keyword(s):  
Acetic Acid ◽  
Culture Filtrate ◽  
Indole Acetic Acid ◽  
Shoot Growth ◽  
High Salinity ◽  
Saline Soils ◽  
Bacterial Strains ◽  
Isolation And Identification ◽  
Endosymbiotic Bacteria ◽  
Root And Shoot Growth

Indole acetic acid is a natural phytohormone which influence the root and shoot growth of the plants. Six (GM1-GM6) endosymbiotic bacteria are isolated from Gracilaria corticata and screened for the production of IAA out of six, three bacterial strains GM3, GM5 and GM6 produced significant amount of IAA 102.4 µg/ml 89.40 µg/ml 109.43 µg/ml respectively. Presence of IAA in culture filtrate of the above strains is further analyzed and confirmed by TLC. As these bacterial strains, able to tolerate the high salinity these can be effectively used as PGR to increase the crop yield in saline soils.

scholarly journals Large seasonal and spatial variation in nano- and microphytoplankton diversity along a Baltic Sea—North Sea salinity gradient

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Malin Olofsson ◽  
James G. Hagan ◽  
Bengt Karlson ◽  
Lars Gamfeldt
Keyword(s):  
Community Structure ◽  
Temporal Variation ◽  
High Salinity ◽  
Salinity Gradient ◽  
Seasonal Succession ◽  
Phytoplankton Diversity ◽  
Cell Abundance ◽  
Low Salinity ◽  
Spatio Temporal ◽  
The Impact

Abstract Aquatic phytoplankton experience large fluctuations in environmental conditions during seasonal succession and across salinity gradients, but the impact of this variation on their diversity is poorly understood. We examined spatio-temporal variation in nano- and microphytoplankton (> 2 µm) community structure using almost two decades of light-microscope based monitoring data. The dataset encompasses 19 stations that span a salinity gradient from 2.8 to 35 along the Swedish coastline. Spatially, both regional and local phytoplankton diversity increased with broad-scale salinity variation. Diatoms dominated at high salinity and the proportion of cyanobacteria increased with decreasing salinity. Temporally, cell abundance peaked in winter-spring at high salinity but in summer at low salinity. This was likely due to large filamentous cyanobacteria blooms that occur in summer in low salinity areas, but which are absent in higher salinities. In contrast, phytoplankton local diversity peaked in spring at low salinity but in fall and winter at high salinity. Whilst differences in seasonal variation in cell abundance were reasonably well-explained by variation in salinity and nutrient availability, variation in local-scale phytoplankton diversity was poorly predicted by environmental variables. Overall, we provide insights into the causes of spatio-temporal variation in coastal phytoplankton community structure while also identifying knowledge gaps.

Threatened habitat at Great Salt Lake: Importance of shallow-water and brackish habitats to Wilson’s and Red-necked phalaropes

The Condor ◽  
2019 ◽  
Vol 121 (2) ◽  
Author(s):  
Maureen G Frank ◽  
Michael R Conover
Keyword(s):  
High Salinity ◽  
Prey Availability ◽  
Salt Lake ◽  
Great Salt Lake ◽  
Hypersaline Lake ◽  
Low Salinity ◽  
Salinity Water ◽  
Threatened Habitat ◽  
Physical Features ◽  
Depth Water

Abstract Great Salt Lake (GSL) is the largest hypersaline lake in North America and is the fall staging area for a high proportion of North America’s Wilson’s Phalaropes (Phalaropus tricolor) and Red-necked Phalaropes (Phalaropus lobatus). Unfortunately, diversion of freshwater for agriculture and development has decreased the size of GSL by 48%. To assess the potential impact of a smaller GSL on phalaropes, we collected data from 2013 to 2015 from sites where large, dense flocks of phalaropes congregated and sites where there were no phalaropes. At each site, we measured the densities of invertebrates that were preyed upon by phalaropes, including larval and adult brine flies (Ephydridae), adult brine shrimp (Artemia franciscana), chironomid larvae (Chironomidae), and corixid adults (Corixidae). Abiotic characteristics measured included water depth, water salinity, water temperature, wind speed, and benthic substrate. We analyzed high-salinity sites separately from low-salinity sites because they contained different invertebrates. High-salinity sites were in Carrington and Gilbert bays and were relatively deep (mostly <2 m). At the high-salinity sites, phalaropes exhibited a preference for sites with an abundance of adult brine flies and for microbialite substrates. The low-salinity sites were in Ogden and Farmington bays and were shallow (<1 m). At low-salinity sites, large phalarope flocks were more likely to occur at sites that were shallower, less saline, and had a high biomass of benthic macroinvertebrates. Our results indicate that physical features and prey availability are both important in determining phalarope habitat use at GSL. Phalaropes prefer to use shallower parts of GSL and brackish waters. These areas will be especially impacted by decreased freshwater inflow into GSL.

Growth and Photosynthetic Responses of Spinach to Salinity: Implications of K+ Nutrition for Salt Tolerance

1990 ◽  
Vol 17 (5) ◽  
pp. 563 ◽  
Author(s):  
WS Chow ◽  
MC Ball ◽  
JM Anderson
Keyword(s):  
Quantum Yield ◽  
Leaf Area ◽  
Shoot Growth ◽  
High Salinity ◽  
Photosynthetic Capacity ◽  
Cytochrome F ◽  
Shoot Biomass ◽  
Unit Leaf Area ◽  
Low Salinity ◽  
Unit Leaf

To compare the effects of K+ under high and low salinity, spinach plants (Spinacia oleracea) were grown in nutrient solutions containing either 50 mM NaCl (low salinity) or 250 mM NaCl (high salinity), with a diurnal regime of 10 h light (~300 μmol photons m-2 s-1, 23°C) and 14 h dark (15°C). At each level of salinity, the nutrient KCl concentration was 0.01, 0.1, 1 or 10 mM. The plant and shoot biomass was greater at low salinity than high salinity and increased with the logarithmic increase in nominal K+ concentrations supplied to the roots. Plant and shoot growth were related to the K+ uptake into the leaves, with leaves having a higher K+ content under low salinity than high salinity. Variation of the K+ content in the leaves, induced by the combinations of nutrient KCl concentrations with high or low salinity, were accompanied by changes in the photosynthetic capacity at light- and CO2-saturation per unit leaf area; there was a greater decrease in photosynthetic capacity with decreasing K+ supply to the roots under high salinity than under low salinity. The photosynthetic capacity was in turn highly correlated with the contents of cytochrome f and ATP synthase per unit leaf area. Under conditions of high salinity and low K+ supply, a reduction in the quantum yield of oxygen evolution also occurred, due to malfunction of photosystem II and, apparently, an increased proportion of light absorbed by non-photosynthetic tissue. The decreases in photosynthetic capacity and quantum yield partly account for the lower plant and shoot biomass at high salinity and low nutrient KCl concentrations. Our results suggest strongly that there are higher K+ requirements for shoot growth under high than low salinity conditions, and that high concentrations of Na+ in the leaves may help to maintain turgor, but cannot substitute for adequate K+ levels in the leaves, presumably because K+ is specifically required for protein synthesis. Increasing the K+ supply at the roots can ameliorate reductions in plant and shoot biomass imposed by an increase in salinity.

scholarly journals Stomatal density, leaf area and plant size variation of Rhizophora mangle (Malpighiales: Rhizophoraceae) along a salinity gradient in the Mexican Caribbean

2017 ◽  
Vol 65 (2) ◽  
Author(s):  
Joanne R. Peel ◽  
Maria C. Mandujano Sanchez ◽  
Jorge Lopez Portillo ◽  
Jordan Golubov
Keyword(s):  
Leaf Area ◽  
Environmental Conditions ◽  
High Salinity ◽  
Stomatal Density ◽  
Salinity Gradient ◽  
Abiotic Factors ◽  
Tree Height ◽  
Plant Size ◽  
Leaf Length ◽  
Low Salinity

In community ecology, the knowledge of abiotic factors, that determine intraspecific variability in ecophysiological and functional traits, is important for addressing major questions, such as plant community assembly and ecosystem functioning. Mangroves have several mechanisms of resistance to salinity and most species exhibit some xeromorphic features in order to conserve water. Leaf area and stomatal density play an important role in maintaining water balance, and gas exchange is regulated by their aperture and density, two traits that vary intraspecifically in response to environmental conditions, such as water stress and salinity. In this study, we evaluated the effects of salinity on stomatal density, leaf area and plant size in R. mangle and we tested for associations among the three variables, across three sites along a natural salinity gradient in the Xel-Há Park, Quintana Roo, Mexico. We hypothesized that high salinity sites would produce smaller plants, with smaller leaves, and fewer stomata. Three sampling sites with different environmental conditions were chosen and salinities were monitored monthly. A total of 542 plants were tagged and tree heights and diameters were measured for each individual within each of the three sampling sites. Three leaves from 20 trees from each site were measured to determine leaf area. Stomatal densities were determined in each leaf using nail polish casts, examining ten 1 mm squares per leaf under an optical microscope. A principal component analysis was used to assess association between tree height, leaf area, and stomatal density for each plot. The salinity gradient was reflected in plant size, producing smaller plants at the higher salinity site. The largest leaves were found at the low salinity site (51.2 ± 24.99 cm2). Leaf length was not correlated to plant size (LL vs. tree height: r= 0.02, P= 0.8205; LL vs. trunk diameter: r= 0.03, P= 0.7336), so we concluded that leaf length is an environmentally plastic trait of red mangroves that may vary as a function of environmental conditions, such as hydric stress caused by elevated salinity. The larger leaves from the low salinity site had lower densities of stomata (65.0 stomata.mm2 SD= 12.3), and increasing salinities did not decrease stomatal density (intermediate salinity site: 73.4 stomata.mm2 SD= 13.5; high salinity site: 74.8 stomata.mm2 SD= 17.3). Our results confirm that stomatal density is inversely related to leaf area (r= -0.29, P < 0.001), especially leaf width (r= -0.31, P < 0.001), and that salinity may increase stomatal density by causing reduction of leaf size.

Effect of Treatment with Saline Solution (NaCl) on Rape Plants in Presence of the Hemp Shives

2017 ◽  
Vol 68 (8) ◽  
pp. 1843-1846
Author(s):  
Sanda Cosarca ◽  
Ioana Rosca ◽  
Alina Coman ◽  
Monica Cristina Nagy Bota ◽  
Corneliu Tanase
Keyword(s):  
Salt Concentration ◽  
Saline Solution ◽  
High Salinity ◽  
Biomass Accumulation ◽  
Saline Soils ◽  
Vegetative Organs ◽  
Low Salinity ◽  
Effect Of Treatment ◽  
Biometric Measurements

The aim of this research was assessing the influence of hemp shives, like amendaments, in saline soils planted with rape (Brassica rapa L.). The growth and development assessing of rape plants in saline soils was achieved through biometric measurements for elongation and gravimetric measurements for the amount of biomass synthesized. Also, it was followed determination of the concentration of assimilating pigment (chlorophyll a, b, total carotenoid pigments) and protein content. It was found that adding hemp shives in soils with low salinity stimulated elongation and germination processes for rape. In soil with high salinity adding hemp shives determine an increase of biomass accumulation in all vegetative organs, comparative with the same salt concentration where we added the amendaments. Hemp shives can be recommended like natural amendaments for soils with high salt concentration.

Size, shape and development time are plastic traits in salt lake ostracods of the Mytilocypris mytiloides (Ostracoda:Cyprididae) species complex

2007 ◽  
Vol 58 (6) ◽  
pp. 511 ◽  
Author(s):  
Terrie Finston
Keyword(s):  
High Salinity ◽  
Size Range ◽  
Salt Lake ◽  
Shell Morphology ◽  
Adult Size ◽  
Size And Shape ◽  
Low Salinity ◽  
Steady Decrease ◽  
Ephemeral Habitat ◽  
Significant Size

The taxonomy of the ostracod genus Mytilocypris is based in part on characters of shell morphology. Specifically, M. minuta, M. mytiloides and M. tasmanica chapmani lack distinctive internal characters and are differentiated largely on size and shape of the shell. The three taxa also differ in the salinity of the habitats they occupy. A field study showed a steady decrease in adult size, spanning the size range of all three taxa, over the course of a season within single lakes, in association with changing salinity and other environmental variables. The present study was conducted to investigate whether each phenotype could be produced under laboratory conditions of variable salinity. Offspring of the three parental phenotypes were raised under high and low salinity. Regardless of parental type, offspring grew more quickly, but reached a smaller size at high salinity, and grew more slowly, but reached a larger size at low salinity. The shape of the shell was found to have a significant size component. Plasticity in size and shape suggests these are unreliable characters for taxonomy. Accelerated development may be an adaptation to living in an ephemeral habitat, with salinity being one of the cues Mytilocypris uses to gauge habitat duration.

Growth and Mineral Nutrition in Salt Stressed Guava ( Psidium guajava L.) cv . Allahabad Safeda

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
ANSHUMAN SINGH ◽  
ASHWANI KUMAR ◽  
R.K. YADAV ◽  
ASHIM DUTTA ◽  
D.K. SHARMA
Keyword(s):  
Electrical Conductivity ◽  
Chemical Composition ◽  
Plant Height ◽  
Salinity Tolerance ◽  
Soil Ph ◽  
High Salinity ◽  
Psidium Guajava ◽  
Sodium Adsorption Ratio ◽  
Saline Soils ◽  
Experimental Soil

Guav a cv . Allahabad Safeda w as grown in saline soils and irrigated with the best av ailable w ater -1 -1 + -1 (EC 2.8 dS m ). Based on chemical composition (pH- 7.1, EC - 2.8 dS m , Na - 20.04 meq l and IW IW sodium adsorption ratio- 4.86), irrigation w ater w as categorized as marginally saline. The soil pH 2 -1 w as mostly below 8.5 but mean electrical conductivity (EC ) v alues ranged from 0.5-2 dS m 2 indicating moderate to high salinity in the experimental soil. After one-y ear of experimentation, fiv e plants randomly selected from each treatment and the data w ere recorded. Plant height -1 -1 significantly increased (LSD 5%) with increase in salinity from 0.5 dS m to 1.4 dS m . A similar -1 trend w as noted with respect to stem girth. The av erage plant height at 0.5, 0.9 and 1.4 dS m salinity lev els w as 98.3 cm, 108.3 cm and 123 cm, respectiv ely whereas the corresponding stem girth v alues -1 w ere 2.24 cm, 2.28 cm and 2.46 cm. At 2 dS m salinity ,how ev er , both av erage plant height (94.6 cm) and stem girth (2.24 cm) significantly decreased and w ere found to be comparable to control (0.5 dS -1 + -1 m ) v alues. Plants show ed negligible Na accumulation in leav es up to 1.4 dS m salinity , but -1 + exposure to elev ated salinity (2 dS m ) significantly increased leaf Na (0.16% DW). These data -1 indicated a salinity tolerance (EC )threshold of about 1.5 dS m inguav a cultiv ar Allahabad Safeda.

Carbon-Isotope, Diatom, and Pollen Evidence for Late Holocene Salinity Change in a Brackish Marsh in the San Francisco Estuary

2001 ◽  
Vol 55 (1) ◽  
pp. 66-76 ◽  
Author(s):  
Roger Byrne ◽  
B. Lynn Ingram ◽  
Scott Starratt ◽  
Frances Malamud-Roam ◽  
Joshua N. Collins ◽  
...  
Keyword(s):  
San Francisco ◽  
High Salinity ◽  
Carbon Isotopic Composition ◽  
Brackish Marsh ◽  
San Francisco Estuary ◽  
Freshwater Inflow ◽  
Water Diversion ◽  
Freshwater Flow ◽  
Low Salinity ◽  
Carbon Isotopic

AbstractAnalysis of diatoms, pollen, and the carbon-isotopic composition of a sediment core from a brackish marsh in the northern part of the San Francisco Estuary has provided a paleosalinity record that covers the past 3000 yr. Changes in marsh composition and diatom frequencies are assumed to represent variations in freshwater inflow to the estuary. Three periods of relatively high salinity (low freshwater inflow) are indicated, 3000 to 2500 cal yr B.P., 1700 to 730 cal yr B.P., and ca. A.D. 1930 to the present. The most recent period of high salinity is primarily due to upstream storage and water diversion within the Sacramento–San Joaquin watershed, although drought may also have been a factor. The two earlier high-salinity periods are likely the result of reduced precipitation. Low salinity (high freshwater flow) is indicated for the period 750 cal yr B.P. to A.D. 1930.

Spatial and seasonal variability of emergent aquatic insects and nearshore spiders in a subtropical estuary

2019 ◽  
Vol 70 (4) ◽  
pp. 541 ◽  
Author(s):  
Martha J. Zapata ◽  
S. Mažeika P. Sullivan
Keyword(s):  
Aquatic Insects ◽  
High Salinity ◽  
Aquatic Insect ◽  
Freshwater Ecosystems ◽  
Dispersal Ability ◽  
Insect Community ◽  
Insect Communities ◽  
Low Salinity ◽  
Subtropical Estuary ◽  
Adult Aquatic Insects

Variability in the density and distribution of adult aquatic insects is an important factor mediating aquatic-to-terrestrial nutritional subsidies in freshwater ecosystems, yet less is understood about insect-facilitated subsidy dynamics in estuaries. We surveyed emergent (i.e. adult) aquatic insects and nearshore orb-weaving spiders of the families Tetragnathidae and Araneidae in a subtropical estuary of Florida (USA). Emergent insect community composition varied seasonally and spatially; densities were lower at high- than low-salinity sites. At high-salinity sites, emergent insects exhibited lower dispersal ability and a higher prevalence of univoltinism than low- and mid-salinity assemblages. Orb-weaving spider density most strongly tracked emergent insect density rates at low- and mid-salinity sites. Tetragnatha body condition was 96% higher at high-salinity sites than at low-salinity sites. Our findings contribute to our understanding of aquatic insect communities in estuarine ecosystems and indicate that aquatic insects may provide important nutritional subsidies to riparian consumers despite their depressed abundance and diversity compared with freshwater ecosystems.

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