Effects of Cold Acclimation Factors on Pythium Snow Rot Resistance of Barley

Abstract

The effects of duration and light conditions of cold acclimation (2°C,12h photoperiod) and environmental condition after cold acclimation on the resistance to Pythium snow rot in barley were studied. The resistance to the spread of symptoms was measured by legion length extended from inoculation point inoculated with a Pythium snow rot pathogen, P. paddicum on the leaf blade. The duration of cold acclimation significantly affected the resistance to snow rot. The significant increase in the resistance was observed after 7 days of cold acclimation treatment. The resistance was further increased by 14 days of cold acclimation, but further prolongation of the cold acclimation period from 14 to 28 days had no effect. During 7-day cold acclimation period, light was necessary to increase the resistance, although light intensity and color had no influence. The resistance attained by the 7-day cold acclimation was nullified by a subsequent exposure to 15°C in darkness for 14 days or cold and dark condition (0.5°C, darkness for 28 days).