Salt Tolerance, Ion Relations and the Effect of Root Medium on the Response of Citrus to Salinity

1995 ◽  
Vol 22 (1) ◽  
pp. 101 ◽  
Author(s):  
R Storey
Keyword(s):  
Salt Tolerance ◽  
Root Morphology ◽  
High Efficiency ◽  
Solution Culture ◽  
Sand Culture ◽  
Fibrous Root ◽  
Rangpur Lime ◽  
Root Medium ◽  
Ion Relations ◽  
Uptake And Transport

This paper describes the ion relations of two citrus genotypes, Etrog citron (Citrus medica L.), a salt-sensitive genotype, and Rangpur lime (Citrus reticulata var. austera hybrid?), a salt-tolerant genotype, under conditions of high NaCl concentrations. Root morphology was modified by establishing seedlings for 6 months in solution or sand culture. When established in sand culture, both genotypes displayed a high efficiency, relative to plants established in solution culture, to exclude Na from leaves, but differed in their capacities to exclude Cl; this capacity was much lower in Etrog citron than Rangpur lime. The net Cl root to shoot transport rates over 7 weeks for Etrog citron and Rangpur lime, treated with 50 mol m-3 NaCl, were 0.25 and 0.07 μmol g-1 root FW h-1, respectively. The net transport rates of Cl in Etrog citron were 10 times those in Rangpur lime between weeks 4 and 7. In Rangpur lime Cl reached pseudo steady-state levels in root and leaf tissue by week 4, thereafter, the net Cl root to shoot transport rate of Rangpur lime decreased while the rates in Etrog citron increased. The accumulation of Na and Cl in leaves of Rangpur lime, in contrast to Etrog citron, was not affected by transpiration. The high salt tolerance of Rangpur lime appears to be associated with low rates of net uptake and transport of Cl, feedback control of net root to shoot transport by Cl levels in the shoot, a low interaction between water flow and Cl and Na fluxes, and a reduction in the leafiroot ratio in response to salinity. When plants were established in solution culture the pioneer roots became elongated and the normal development of the laterals into a fibrous root system was suppressed. Plants of both genotypes, previously established in solution culture and then treated with 50 mol m-3 NaCl, accumulated levels of Na and Cl in leaves up to 200-400 mol m-3. Under these conditions the rates of net Cl root to shoot transport over the 7 weeks were 0.53 and 0.56 μmol g-1 root FW h-1 for Etrog citron and Rangpur lime, respectively. These high rates of Cl uptake and transport were attributed to changes in root permeability and increases in passive ion fluxes. Keywords: citrus, root morphology, root medium, transpiration, Cl, Na, salt accumulation, salinity.

Ion Regulation in the Organs of Casuarina Species Differing in Salt Tolerance

1986 ◽  
Vol 13 (4) ◽  
pp. 533 ◽  
Author(s):  
N Aswathappa ◽  
EP Bachelard
Keyword(s):  
Salt Tolerance ◽  
Concentration Gradient ◽  
Solution Culture ◽  
Time Sequence ◽  
Sand Culture ◽  
Short Term ◽  
Ion Regulation ◽  
Ion Concentrations ◽  
Tolerant Species

Distribution of Na+, Cl-, K+, Ca2+ and Mg2+ was studied in individual organs of two highly tolerant and one moderately tolerant species of Casuarina. The highly tolerant species (C. equisetifolia and C. glauca) accumulated little Na+ and Cl- in their shoots and the concentrations of Na+ and Cl- decreased from old to young growing needles. The concentrations of Na+ and Cl- were much higher in shoots of the moderately tolerant species (C. cunninghamiana) and a concentration gradient between old and young needles was not observed. The same pattern of distribution of Cl- in C. equisetifolia was found in seedlings exposed to both short term (13 days at 100 mol m-3 NaCl in solution culture), and long term (6 months at 250 mol m-3 NaCl in sand culture) salinisation. The three species showed little difference in their root ion concentrations. A time sequence experiment of Cl- uptake indicated that the better exclusion of Cl- from the shoots of C. equisetifolia than C. cunninghamiana was due to a lower rate of Cl- uptake and lower net transport into the shoot rather than to its retention in the roots, or reabsorption at the proximal root or hypocotyl.

scholarly journals Image analysis techniques to characterise white clover root morphology

1998 ◽  
pp. 187-191
Author(s):  
Debbie Care ◽  
Shirley Nichols ◽  
Derek Woodfield
Keyword(s):  
Image Analysis ◽  
White Clover ◽  
Root Morphology ◽  
Root Systems ◽  
Solution Culture ◽  
Two Dimensions ◽  
Three Dimensions ◽  
Analysis Techniques ◽  
Clover Root ◽  
Image Analysis Techniques

The use of low-ionic-strength hydroponic culture and image analysis techniques to discriminate and isolate morphologically distinct, genetically differentiated root types within white clover is described. Advantages of this method include the ability to view the genetic expression of the root systems without the modifying effects of growth in soil, to examine the growth and structure of roots over time, and to store the images for further examination. It is recognised that although the root systems grow in three dimensions, they are constrained to two dimensions by the flatbed scanner. However, the morphological parameters determined by image analysis would not be altered whether this analysis was measured in two or three dimensions. Keywords: image analysis, root morphology, solution culture, Trifolium repens

Root Morphology and Secretion of two subtropical tree species to NH4+-N and NO3–-N Deposition

2020 ◽  
Author(s):  
Rui Zhang ◽  
Yi Wang ◽  
Zhichun Zhou
Keyword(s):  
Root Growth ◽  
Root System ◽  
Root Morphology ◽  
Tree Species ◽  
Southern China ◽  
N Deposition ◽  
Fibrous Root ◽  
Nitrogen And Phosphorus ◽  
Root Absorption ◽  
Tap Root

Abstract Background: Both NH4+ and NO3– are capable of greatly influencing plants’ growth and biomass. However, the belowground responses of subtropical trees to either NH4+ or NO3– deposition remain poorly understood. Here, we discuss how these two forms of N deposition can affect root development, and experimentally analyzed how they could impact nitrogen and phosphorus absorption in two types (broadleaved with a fibrous root system vs. conifer with a tap root system) of subtropical tree species. Results: In a greenhouse in southern China, 1-year-old S. superba and P. massoniana seedlings grown on P-limited and P-normal soil were treated with NaNO3 and NH4Cl solutions of 0, 80, and 200 kg N ha–1 year–1, corresponding to the control, N80, and N200 groups, respectively. Root phenotype characteristics and metabolism ability were measured after 8 months of growth. The results showed that the root morphology and physiology variables differed significantly between the two species under different N and P treatments. Although S. superba had a larger quantity of roots than P. massoniana, both its root growth rate and root absorption were respectively lower and weaker. N addition differentially affected root growth and activity as follows: (1) NO3–-N80 and NH4+-N80 increased root growth and activity of the two species, but NH4+-N80 led to thicker roots in S. superba; (2) NO3–-N200 and NH4+-N200 had inhibitory effects on the roots of P. massoniana, for which NH4+-N200 led to thinner and longer roots and even the death of some roots; and (3) NH4+-N could promote metabolic activity in thicker roots (> 1.5 mm) and the NO3–-N was found to stimulate activity in thinner roots (0.5–1.5 mm) in the fibrous root system having a larger quantity of roots, namely S. superba. By contrast, NO3–-N and NH4+-N had an opposite influence upon functioning in the tap root system with a slender root, namely P. massoniana. Conclusion: We conclude P. massoniana has a much higher root absorption efficiency; however, nitrogen deposition is more beneficial to the root growth of S. superba.

Effect of NaCl on the Growth of Whole Plants and Their Corresponding Callus Cultures

1981 ◽  
Vol 8 (3) ◽  
pp. 267 ◽  
Author(s):  
MK Smith ◽  
JA Mccomb
Keyword(s):  
Salt Tolerance ◽  
Callus Cultures ◽  
Solution Culture ◽  
Cellular Level ◽  
Plant Responses ◽  
Salt Glands ◽  
Salt Level ◽  
Whole Plant ◽  
Nutrient Solution Culture ◽  
Whole Plants

The effect of NaCl on growth was examined for whole plants and callus cultures of a salt-sensitive glycophyte (Phaseolus vulgaris L.), a salt-tolerant glycophyte (Beta vulgaris L.) and two halophytes (Atriplex undulata D. Dietr., which has salt glands, and Suaeda australis (R. Br.) Moq., a succulent). Whole plants were grown in nutrient solution culture at NaCl concentrations of 0.1-250 mM. Callus cultures were initiated from the same seed stock, and similar saline regimes were imposed. Whole plant responses were characteristic for the various types of plants: P. vulgaris showed a decrease in growth with increasing salinity; B. vulgaris showed a slight increase in growth at the intermediate salt level and a decrease at higher levels; A. undulata and S. australis showed well defined growth optima at 62.5 mM and 125 mM NaCl, respectively. Callus cultures of P. vulgaris and the two halophytes grew very poorly when salinity was increased. Callus of B. vulgaris showed the same tolerance to salt as did the whole plants. Thus salt tolerance of the halophytes depends on the anatomical and physiological complexity of the intact plant while callus from B. vulgaris appears to have a mechanism(s) of salt tolerance which operates at the cellular level.

scholarly journals LEAF ELEMENTAL CONTENT AND GROWTH OF `SHAWNEE' BLACKBERRY AS INFLUENCED BY APPLIED K AND NA

HortScience ◽  
1993 ◽  
Vol 28 (4) ◽  
pp. 273E-273
Author(s):  
James M. Spiers
Keyword(s):  
Salt Tolerance ◽  
Plant Growth ◽  
Sand Culture ◽  
Elemental Content ◽  
Fe And Mn ◽  
K Fertilizer ◽  
K Fertilization ◽  
Na Uptake

The effects of varying potassium and sodium fertilization levels on 'Shawnee' blackberry (Rubrus, subgenus Eubatus, spp.) plant growth and leaf elemental content were studied in sand culture experiments. Increasing K fertilizer levels linearly increased K, but decreased Mg and Zn in the leaves. Concentrations of Na, Ca, Cu. Fe, and Mn were not significantly influenced by K fertilization. Plants contained six times more Na with high than with low Na fertilization. Na fertilization did not significantly affect leaf K, Ca, Mg, Fe, Cu or Zn, but leaf Mn was linearly reduced by increasing Na fertilization. Leaf K and Na were directly influenced by the amounts of supplied K and Na. 'Shawnee' blackberries readily take up Na but exhibit some salt tolerance at low to moderate Na fertilization levels. At high Na levels, they appear to lack a mechanism to reduce Na uptake, which results in reduced plant growth.

scholarly journals Relationships between Salt Tolerance of Green Soybeans and Calcium Sulfate Applications in Sand Culture

1981 ◽  
Vol 50 (3) ◽  
pp. 326-331 ◽  
Author(s):  
Akira NUKAYA ◽  
Masao MASUI ◽  
Akira ISHIDA
Keyword(s):  
Salt Tolerance ◽  
Calcium Sulfate ◽  
Sand Culture

scholarly journals Salt tolerance of mango rootstocks (Magnifera indica L. cv. Osteen)

2003 ◽  
Vol 1 (1) ◽  
pp. 68 ◽  
Author(s):  
V.H. Duran ◽  
A. Martinez Raya ◽  
J. Aguilar
Keyword(s):  
Water Quality ◽  
Electrical Conductivity ◽  
Salt Tolerance ◽  
Root System ◽  
Irrigation Water ◽  
Relative Tolerance ◽  
Na Ions ◽  
Uptake And Transport

The aim of this work was to establish the criteria to determine the relative tolerance of mango rootstocks (Mangiferaindica L.) to high Cl- and Na+ concentrations present in irrigation water. Two rootstocks, Gomera-1 and Gomera-3 grafted with the cultivar Osteen, were subjected to study. Grafted plants were exposed to salinized irrigation watersmeasured by electrical conductivity (1.02, 1.50, 2.00 and 2.50 dS m-1). Results indicated differences in retainingtoxic elements in different organs (roots, stem, or leaves) of both rootstocks. Gomera-3 was more sensitive as took uphigher amounts of Cl- and Na+ than Gomera-1. Gomera-1 was more tolerant, being the tolerance possibly associatedwith the capacity of this rootstock to restrict the uptake and transport of Cl- and Na+ ions from the root system to theaboveground parts. The Cl- ions were more toxic in rootstock and cultivar leaves, while the Na+ ions were more toxicin the roots. Therefore, the present study reveals that Gomera-1 proved to be the most adaptable rootstock to salineconditions, making it feasible for use in areas with low water quality.

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