Determination of frost hardiness of Eucalyptus using the electrical conductivity of diffusate in conjunction with a freezing chamber

1988 ◽  
Vol 18 (5) ◽  
pp. 595-600 ◽  
Author(s):  
P. M. Hallam ◽  
W. N. Tibbits
Keyword(s):  
Electrical Conductivity ◽  
Frost Hardiness ◽  
Lethal Temperature ◽  
Conductivity Method ◽  
Water Conductivity ◽  
Leaf Discs ◽  
Significant Difference ◽  
Maximum Conductivity ◽  
Electrical Conductivity Method

An electrical conductivity method for determining frost hardiness of tissue discs punched from Eucalyptus leaves is described. Samples were exposed to convective heat loss in an air-filled chamber. Rates of cooling and desired frost temperatures were electronically controlled and maintained. Supercooling of tissue was effectively eliminated by addition of small amounts of AgI and water. Conductivity of diffusate was measured as a means of quantifying tissue damage following frost. Relative conductivity was determined with reference to subsequent measurements following heating the discs to 70 °C which resulted in maximum conductivity. Exposure of leaf discs to temperatures below the lethal temperature for these species (<−10 °C) resulted in similar maximum conductivity readings. The technique is evaluated to assess its potential to distinguish small differences in frost hardiness caused by genotype and environment. For both E. delegatensis and E. nitens there was no significant difference in frost hardiness expressed in terms of mean lethal temperature when comparing leaf discs with frosting whole seedlings.

scholarly journals Condutividade elétrica como indicador de danos por temperaturas baixas em folhas de feijão

2019 ◽  
Vol 40 (3) ◽  
pp. 1011
Author(s):  
Juliandra Rodrigues Rosisca ◽  
Carolina Maria Gaspar de Oliveira ◽  
Altamara Viviane de Souza Sartori ◽  
Renata Stolf-Moreira ◽  
Marcelo Augusto de Aguiar e Silva ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Cold Stress ◽  
Protein Content ◽  
Pearson Correlation ◽  
Total Protein Content ◽  
Leaf Discs ◽  
Randomized Design ◽  
Bean Plants ◽  
C 30

The electrical conductivity test indirectly evaluates cell membrane disorganization by quantifying the electrolytes released into the water after tissue imbibing. The objective of this work was to evaluate methodological variations in the electrical conductivity test, for it to serve as an indicator of low temperature-induced damages and estimate the cold tolerance of bean plants. Cultivar IPR Uirapuru plants were subjected to minimum temperatures of 4 °C, 2 °C, 0 °C, -1 °C, -2 °C, -3 °C, and -4 °C for 1 h in a growth chamber under controlled conditions. After the treatment period, the response of plants to cold stress was evaluated by determination of the total protein content, and catalase (CAT) and ascorbate peroxidase (APX) enzymatic activities, and evaluation of photosystem II (Fm/Fv) efficiency and leaf anatomy. These results were compared with those obtained in the electrical conductivity test, which was performed in plants under cold stress as well as under a non-stress environment, with 2, 4, 6, and 8 leaf discs immersed in 30 mL of distilled water for 24 h in BOD, at temperatures of 25 °C, 30 °C, and 35°C. Analysis of variance was performed using a completely randomized design, and for electrical conductivity, a number of discs × cold stress temperature combinations were used for each soak temperature. The averages were compared using the Turkey's test at 5% and 10% probability. Pearson correlation coefficient (r) between the conductivity averages and other cold stress evaluation data was also performed. The results showed a marked reduction in the ratio (Fv/Fm) only in the treatments at -3 °C and -4°C, which indicated tissue death. At temperatures below 0°C, there was a collapse of the leaf blade tissues, and it was not possible to differentiate the palisade parenchyma from the spongy parenchyma in the treatments at -2°C, -3°C, and -4°C. There was an increase in the protein content since the temperature -3°C. The enzyme activity of CAT decrease at -4°C whereas that of APX increased. In the electrical conductivity test, there was a significant interaction between soak temperature and the number of discs, and an increase in conductivity of the solution with a decrease in temperature was verified in several treatments, among which, the combination that best correlated with the other tests was 25°C with six leaf discs. It was concluded that the electrical conductivity test presents results similar to those obtained from other physiological, biochemical, and anatomical tests, and therefore, it can be used to evaluate the damage caused by low temperatures in bean plants.

Determining batch moisture content by the electrical conductivity method

1968 ◽  
Vol 25 (7) ◽  
pp. 402-404
Author(s):  
K. T. Bondarev ◽  
N. P. Grimal'skii ◽  
G. E. Knigin ◽  
E. S. Gnedashevskaya
Keyword(s):  
Electrical Conductivity ◽  
Moisture Content ◽  
Conductivity Method ◽  
Electrical Conductivity Method
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