scholarly journals ON THE DIFFERENTIATION OF THE LEAF TISSUE FLUIDS OF LIGNEOUS AND HERBACEOUS PLANTS WITH RESPECT TO OSMOTIC CONCENTRATION AND ELECTRICAL CONDUCTIVITY

1921 ◽  
Vol 3 (3) ◽  
pp. 343-345 ◽  
Author(s):  
J. Arthur Harris ◽  
Ross Aiken Gortner ◽  
John V. Lawrence
Keyword(s):  
Electrical Conductivity ◽  
Leaf Tissue ◽  
Herbaceous Plants ◽  
Osmotic Concentration ◽  
Tissue Fluids

Maximum values of osmotic concentration in plant tissue fluids

1921 ◽  
Vol 18 (4) ◽  
pp. 106-109 ◽  
Author(s):  
J. A. Harris ◽  
R. A. Gortner ◽  
W. F. Hofmann ◽  
A. T. Valentine
Keyword(s):  
Plant Tissue ◽  
Osmotic Concentration ◽  
Tissue Fluids

scholarly journals RESPONSE OF CATHARANTHUS ROSEUS “GRAPE COOLER” TO MEDIA AND FERTILIZER SOLUTION CONCENTRATION USING SUBIRRIGATION

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 687c-687
Author(s):  
G.C. Elliott ◽  
R.J. McAvoy ◽  
M. Abbott
Keyword(s):  
Electrical Conductivity ◽  
Catharanthus Roseus ◽  
Leaf Tissue ◽  
Solution Concentration ◽  
Essential Elements ◽  
Fresh Weight ◽  
The Third ◽  
Saturated Media ◽  
Final Harvest ◽  
Fertilizer Solution

Seedlings of Catharanthus roseus “Grape Cooler” was transplanted to cell packs of media: peat-vermiculite-perlite (MM220), peat-hydrophilic rockwool (ABS), and peat-hydrophobic rockwool (REP) and grown in subirrigation trays using 20N-4.4P-17K fertilizer at 50, 150 or 250 ppm N applied at each irrigation. Shoots of four plants in each of two replications were harvested 2, 3, 4 and 5 after transplant. Leaf samples from the third harvest were analyzed for essential elements. Electrical conductivity (EC) was measured in saturated media extracts at each harvest. Significant media by fertilizer interactions were obtained for fresh weight and leaf area at the final harvest. Greatest growth was obtained with 50 ppm N in ABS, but with 150 ppm N in MM 220 and REP. In tehse, growth was similar at 50 and 150 ppm N, but less growth REP than MM220 at 250 ppm. More growth was produced with ABS at 50 ppm N, but less at 150 or 250 ppm N. Leaf tissue N increased 38.5 to 54.5 mg g-1 dry wt. as fertilized increased 50 to 150 ppm, while other nutrients were not significantly affected. Media EC increased with time and fertilizer concentration, with EC in all media fertilized with 250 ppm N exceeding 4.5 dS m-1 at the final harvest.

scholarly journals Comparative analysis of gene expression in tea plant (Camellia sinensis (L.) Kuntze) under low-temperature stress

2020 ◽  
Vol 24 (6) ◽  
pp. 598-604
Author(s):  
L. S. Samarina ◽  
A. O. Matskiv ◽  
N. G. Koninskaya ◽  
T. A. Simonyan ◽  
V. I. Malyarovskaya ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Comparative Analysis ◽  
Low Temperature ◽  
Temperature Stress ◽  
Leaf Tissue ◽  
Frost Tolerance ◽  
Tea Plant ◽  
Low Temperature Stress ◽  
Germplasm Collections ◽  
Significant Difference

Low-temperature stress is one of the main factors limiting the distribution and reducing the yield of many subtropical crops, including the tea crop. Efficient breeding to develop frost-tolerant cultivars requires a reliable set of genetic markers for identifying resistance donors, and that is why it is necessary to reveal the specific genetic response in frost-tolerant genotypes in comparison with frost- susceptible ones. In this work, we performed a comparative analysis of the expression of 18 tea genes (ICE1, CBF1, DHN1, DHN2, DHN3, NAC17, NAC26, NAC30, bHLH7, bHLH43, P5CS, WRKY2, LOX1, LOX6, LOX7, SnRK1.1, SnRK1.2, SnRK1.3) under cold and frost conditions in two tea genotypes, tolerant and susceptible. Low-temperature stress was induced by placing the potted plants in cold chambers and lowering the temperature to 0…+2 °С for 7 days (cold stress), followed by a decrease in temperature to –4…–6 °С for 5 days (frost stress). Relative electrical conductivity of leaf was measured in response to the stress treatments, and a significant difference in the frost tolerance of the two tea genotypes was confirmed. Cold exposure did not lead to a change in the electrical conductivity of leaf tissue. On the other hand, frost treatment resulted in increased REC in both genotypes and to a greater extent in the susceptible genotype. Increased expression of all the genes was shown during cold and frost. The genes that were strongly expressed in the tolerant tea genotype were revealed: ICE1, CBF1, DHN2, NAC17, NAC26, bHLH43, WRKY2, P5CS, LOX6, SnRK1.1, SnRK1.3. These genes can be proposed as markers for the selection of frost-tolerance donors in tea germplasm collections. Additionally, it was shown that the tolerant genotype is characterized by an earlier response to stress at the stage of cold acclimation. The study of the expression of the identified genes in different organs of tea plants and in different exposures to low temperature is relevant for further investigations.

scholarly journals Solution Electrical Conductivity and Ratio of Nitrate to Other Nutrients Affect Accumulation of Nitrate in Hydroponic Lettuce

HortScience ◽  
2003 ◽  
Vol 38 (2) ◽  
pp. 222-227 ◽  
Author(s):  
Martin P.N. Gent
Keyword(s):  
United States ◽  
Electrical Conductivity ◽  
Stepwise Regression ◽  
Leaf Tissue ◽  
Dry Weight ◽  
High Irradiance ◽  
Tissue Composition ◽  
Nitrate Supply ◽  
N Treatment ◽  
Leaf Nitrate

Solution electrical conductivity (EC) and the supply of nitrate in proportion to other elements (nitrate supply ratio) should effect tissue composition of lettuce (Lactuca sativa L.) grown in hydroponic solution. These parameters were varied in several series of successive plantings in greenhouses in the northeast United States. In 1996, when the treatments differed only in EC, 0.65 and 0.9 dS·m-1, but not in nitrate supply ratio, leaf tissue had more nitrate and total reduced-N and lettuce grew faster in the solution with higher EC. Over four series of plantings in 1997 and 1998, the nitrate supply ratio of a low-N treatment was only 60% of that for a high-N treatment, and EC was varied from 1.2 to 2.0 dS·m-1. In 1997 and 1998, tissue nitrate was lower in the low-N treatment only when EC was less than in the high-N treatment. However, under irradiance greater than 10 MJ m-2 per day, the lower EC also slowed growth. Stepwise regression over data from all experiments showed leaf nitrate was primarily a function of EC, and a term that described the interaction between irradiance and EC. Due to selective uptake by the plants, the ratio of elements in the recirculating solution differed from the ratio in which they were supplied. Under irradiance less than 10 MJ m-2 per day and solution EC greater than 1.5 dS·m-1, nitrate accumulated in solution to a concentration greater than expected from simple dilution of the concentrates. Tissue nitrate was also related to solution nitrate, increasing by 0.08-0.09 mg·g-1 dry weight per 1 mg·L-1 increase in solution nitrate. To prevent a rise in tissue and solution nitrate under low irradiance, both solution EC and nitrate supply ratio had to be reduced by about one-third, compared to the conditions required for rapid growth under high irradiance.

Tomato plant growth as affected by horizontally unequal osmotic concentrations in rock-wool.

1981 ◽  
Vol 29 (3) ◽  
pp. 189-197
Author(s):  
A. Cerda ◽  
J.P.N.L.R. van Eysinga
Keyword(s):  
Electrical Conductivity ◽  
Plant Growth ◽  
Root Zone ◽  
Nutrient Concentrations ◽  
Osmotic Concentration ◽  
Tomato Plants ◽  
Split Root ◽  
Split Root System ◽  
The Mean ◽  
Rock Wool

Tomato plants, cv. Moneydor, were grown in rockwool in a split-root system with equal or different osmotic concentrations. Fruit yield was negatively correlated with the mean electrical conductivity (EC) of both parts of the system. In treatments with two different EC values in the root zone, root development was better in the part with the low EC, and water uptake was higher. Nutrient concentrations showed an increase in the part with the low EC when differences in EC between both parts were 4 mS/cm [4 mmho/cm] or more. A possible explanation is that solutes move through the roots from the part with high to the part with the low osmotic concentration. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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