Relationship between leaf water spin‐lattice relaxation time and water relation parameters in three wheat cultivars

Abstract

ABSTRACT Pot culture studies were conducted using two drought‐tolerant and one susceptible cultivar of wheat ( Triticum aestivum L.) under three different moisture regimes. Proton spin‐lattice relaxation time, T 1 , leaf water content, LWC, leaf water potential, Ψ, solute potential, Ψ s and turgor potential, Ψ p were measured from 45 to 75 d after sowing at weekly intervals. The three cultivars did not differ significantly in their values of LWC, leaf water potential, and their components in the stressed and unstressed plants; but they did differ significantly in their T 1 values both under stressed and unstressed conditions on all days of measurement, with the drought tolerant cultivars having a higher T 1 compared to the susceptible cultivar. This suggests that leaf water T 1 is a better parameter for describing plant water status than the traditional water relation indices. The relation between Ψ and T 1 was logarithmic, indicating the similarity between T 1 and water activity of the cellular water.