Abstract
Nutritional stress generally affects the resistance of higher plants against pathogenic attack. It is well known that the plants grown under excess nitrogen tend to induce various pathogenic symptoms. The present investigation was undertaken to examine the influence of excess ammonia treatment on stress response of Cyclamen persicum inoculated with Fusarium oxysporum f.sp. cyclaminis.
C. persicum grown for 10 months was treated with 50 ppm and 400 ppm ammonium sulfate. After two days of ammonia treatment the plants were inoculated with F. oxysporum f.sp. cyclaminis. The symptom characteristic to Fusarium wilt appeared after 3 to 4 weeks in the plants treated with high ammonia. Cellular components such as salicylic acid and putrescine increased with the high ammonia treatment while anthocyanin content strikingly decreased. High ammonia treatment also resulted in the increment of tissue glutamine level and its accumulation was further promoted by the Fusarium inoculation.
