Induction of systemic resistance in tomato plants against Fusasium wilt disease by salicylic acid .

Abstract

This study was conducted to evaluate the efficiency of salicylic acid as chemical inducer to stimulate tomato plant resistance against Fusarium wilt disease caused by the phytopathogenic fungus Fusarinm oxysporum under laboratory , greenhouse and field conditions. Also, the study was led to select the active concentrations of salicylic acid in inhibition the fungus growth (Fusarium oxysporum) , three concentrations were studied (50,100 and 200) ppm .The results showed that tomato seed soaked in multi concentrations from salicylic acid led to inhibition the radial growth and the dry weight of biomass and the number of spores of pathogen , 200 ppm concentration showed the best results which recorded 15 mm,0.18g,4.66x106 spore/ cm2as compared to control treatment(0.0 ppm concentration , 43.33 mm , 0.27g, 28.50 x 106 spore / cm2 respectively. The results of tomato seed treatment with salicylic acid led to a significant increment in percentage of seeds germination, plant height , fresh and dry weight of plant as compared to control treatment under greenhouse conditions . 200 ppm of salicylic acid treatment recorded 94.6%, 54.6 cm, 65.33 g/ plant, 29.0 g / plant respectively , while control treatment recorded 81.6%,42.7 cm,16.3g / plant , 8.4 g/plant respectively . The results showed that tomato seeds treatment in different concentrations of salicylic acid 50,100,200 ppm gave a significant increment in most tested growth parameters under greenhouse conditions (plant height, root length. no. of leaves /plant , no. of flowers /plant , no. of fruits / plant , average of fruits weight / plant, 200 ppm of salicylic acid treatment significantly increased on the following parameters average which recorded 54.33, 27.33 cm, 14.0 leaves / plant , 11.67 flowers / plant , 3.83 fruits / plant , 62.33 g/ plant ) respectively , while control treatment recorded 42.73, 9.93 cm , 6.97 leaves /plant, 3.10 flowers / plant , 1.20 fruits / plant , 16.33 g / plant respectively. The results of tomato seedlings treatment with salicylic acid led to increment in most the tested growth parameters under field conditions plant height, root length, no. of branches / plant , no. of fruits / plant , average of fruits weight / plant , fresh and dry weight of plant and disease severity as compared to other treatments .