the role of total nitrogen content of leaves in temperature sensitivity of barley cultivars to puccinia hordei and changes in nitrogen content occurring during development of the disease

the total nitrogen content of three barley cultivars: cehada capa (resistant at 25ac), cl 1243 (resistant at 5°c) and rika 1 (susceptible at all temperatures) to puccinia hordei was determined and compared in healthy and infected plants at 5° and 26°c. the results indicate that the total nitrogen content of cv. cehada capa leaves was greater than that of cl 1243 and rika 1 and that of cl 1243 was greater than that of rika 1 when plants were grown at 26°c. when plants were grown at 5°c, the percentage of total nitrogen content of leaves of cv. cebada capa was significantly greater than that of cl 1243 and rika 1, but no differences were found between rika 1 and cl 1243. it was concluded that the total nitrogen content has no role in the temperature sensitivity of barley cultivars. in most cases, especially in susceptible cultivars, the nitrogen content of infected leaves was greater than that of healthy plants when plants were incubated at 26°c, but there were no significant differences between total nitrogen content of infected leaves and that of their healthy control when plants were incubated at 5°c.