Simultaneous monitoring of electrical capacitance and water uptake activity of plant root system

Abstract

A b s t r a c t. Pot experiments were designed to test the applicability of root electrical capacitance measurement for in situ monitoring of root water uptake activity by growing cucumber and bean cultivars in a growth chamber. Half of the plants were inoculated with Funneliformis mosseae arbuscular mycorrhizal fungi, while the other half served as non-infected controls. Root electrical capacitance and daily transpiration were monitored during the whole plant ontogeny. Phenology-dependent changes of daily transpiration (related to root water uptake) and root electrical capacitance proved to be similar as they showed upward trends from seedling emergence to the beginning of flowering stage, and thereafter decreased continuously during fruit setting. A few days after arbuscular mycorrhizal fungi-colonization, daily transpiration and root electrical capacitance of infected plants became significantly higher than those of non-infected counterparts, and the relative increment of the measured parameters was greater for the more highly mycorrhizal-dependent bean cultivar compared to that of cucumber. Arbuscular mycorrhizal fungi colonization caused 29 and 69% relative increment in shoot dry mass for cucumbers and beans, respectively. Mycorrhization resulted in 37% increase in root dry mass for beans, but no significant difference was observed for cucumbers. Results indicate the potential of root electrical capacitance measurements for monitoring the changes and differences of root water uptake rate.K e y w o r d s: mycorrhiza, phenology, root electrical capacitance, transpiration, water uptake INTRODUCTION

Sensing the electrical properties of roots: A review

“…Investigations of root development with time using ECM showed that there are important temporal variations in the measured capacitance (Cseresnyés et al., 2018; Cseresnyés, Rajkai, & Takács, 2016; Cseresnyés, Takács, Füzy, & Rajkai, 2014; Cseresnyés, Takács, Füzy, Végh, & Lehoczky, 2016; Dalton, 1995). Cseresnyés et al.…”

“…Cseresnyés et al. (2014) found that root water uptake and C root increased from the emergence of a seedling to the beginning of flowering and then decreased continuously during the fruit setting for cucumber ( Cucumis sativus L.) and bean ( Phaseolus vulgaris L.). Similarly, ECM presented in Cseresnyés et al.…”

“…Investigations of root development with time using ECM showed that there are important temporal variations in the measured capacitance (Cseresnyés et al, 2018;Cseresnyés, Rajkai, & Takács, 2016;Cseresnyés, Takács, Füzy, & Rajkai, 2014;Cseresnyés, Takács, Füzy, Végh, & Lehoczky, 2016;Dalton, 1995). Cseresnyés et al (2014) found that root water uptake and C root increased from the emergence of a seedling to the beginning of flowering and then decreased continuously during the fruit setting for cucumber (Cucumis sativus L.) and bean (Phaseolus vulgaris L.). Similarly, ECM presented in Cseresnyés et al (2018) identified peak activity with a capacitance value of 96.4 nF at a period that coincided with the completion of flowering 92 d after sowing.…”

Imaging and functional characterization of crop root systems using spectroscopic electrical impedance measurements

“…These methods, long established in the near-surface geophysics community, capture electrical material properties of the subsurface, or laboratory samples, which can then be related to geophysical properties such as temperature (e.g., Sen and Goode 1992), salinity (e.g., Rhoades et al 1989), porosity/soil water content (e.g., Archie 1942;Oberdörster et al 2010;Whalley et al 2017), clay content (e.g., Breede et al 2012), and even certain root parameters (e.g., Chloupek 1972;Dalton 1995;Cseresnyés et al 2013;Wu et al 2017, and references therein). It has also been recognized that electrical methods can not only be used to characterize structural, but also functional properties of root systems (e.g., Dalton 1995;Cseresnyés et al 2014Cseresnyés et al , 2016.…”