QUANTITATIVE ESTIMATION METHOD OF PLANT ADAPTATION RESPONSES TO SALINE ENVIRONMENT USING MICROWAVE SENSING
In this study, in order to develop an estimation method of plant adaptation responses to a saline environment using microwave sensing, plants which have different salinity tolerances were examined after being grown hydroponically and exposed to a saline environment for 2, 4 or 6 weeks. Experimental results showed the dielectric relaxation spectra changed as the plant leaves adapted to the saline environment, and there were three main types of spectral change pattern. The plants associated with each of the three types of spectral change pattern did not correlate with the conventional classification of salinity tolerance of the plants (as sensitive crop, moderately sensitive crop, moderately tolerant crop and tolerant crop), suggesting there are patterns of spectral change peculiar to each variety of plant. The patterns of change in dielectric properties on the Cole-Cole plots showed that the dielectric properties of all plant materials changed toward those of a halophytic plant after exposure to a saline environment, as if the plants tried to become halophytic plants. The relationship between dielectric properties of plant leaves and water potentials also showed a similar phenomenon. In addition, the relationship between loss tangent and water potential had a nearly linear relationship. Experimental results showed the potential of using microwave sensing for quantitative estimation of plant adaptation responses to a saline environment and the degree of salinity of the environment in the rhizosphere.
Shimomachi, T., Takemasa , T., Kurata, K., Kobashigawa, C., Omoda, E. and Takakura, T. (2008). QUANTITATIVE ESTIMATION METHOD OF PLANT ADAPTATION RESPONSES TO SALINE ENVIRONMENT USING MICROWAVE SENSING. Acta Hortic. 797, 463-468
complex permittivity, dielectric relaxation spectra, salinity tolerance, rhizosphere