A method of estimating the cold hardiness of cereals by measuring electrical conductance after freezing

Abstract

SUMMARY A technique is described in which cereal seedlings after germination and hardening under controlled conditions in a growth chamber were subjected to freezing in tubes immersed in a solution of ethylene glycol. Susceptibility to freezing was estimated by measuring electrical conductance on the linear 0–100 scale of a standard ‘Avometer’ using platinum probes inserted near the base of the lamina of the first leaf. The use of the technique is illustrated by two experiments with winter barley cultivars chosento represent a wide range of winter hardiness. Although significant cultivar differences in mean conductance existed prior to freezing, adequate differentiation was obtained by measurements after freezing only. The differentiation of these cultivars on mean conductance values after freezing was well correlated with their established winter hardiness. It is concluded that the technique is sufficiently sensitive for the preliminary screening of early generation material but that, because of significant cultivar × hardening-duration interactions, advanced breeding lines should be tested over a range of hardening and freezing regimes.