Effect of plant growth regulator, gibberellic acid( GA3) and antibiotic, pencillin in the multiplication of tomato mosaic virus (ToMV)

Abstract

This experiment was conducted in Biology Department, Science College, University of Al- Anbar in 2018 season, to test the inhibition activity of gibberillic acid and antibiotic, pencillin against tomato mosaic virus.Two compounds were used to investigate resistance induction in tomato plants against the tomato mosaic virus (ToMV). In this study 50 ppm and 100 ppm of gibberillic acid and pencillin respectively were used to identify the activity in the inhibition of virus replicating or inducing the resistance in tomato plants against this virus. The results showed that the concentration 100 ppm of gibberillic acid is the best in the inhibition ratio ( in the experiment of mixture tomato mosaic virus inoculum and gibberillic acid or pencillin). It gave inhibition ratio 67.44 % (lesions number, 0.8133 lesion.cm-2), while the concentration 50 ppm gave inhibition ratio 54.92 % ( lesions number 1.126 lesion.cm-2), Moreover, the concentration 100 ppm of pencillin gave inhibition ratio 79 % ( lesions number, 0.580 lesion.cm-2) in comparison with the concentration 50 ppm which gave 74 % ( lesions number 0.712 lesion.cm-2).The results also showed, when treating tomato plants with the concentration 100 ppm of gibberillic acid by spray on plant, gave inhibition ratio 56.44 % compared with the concentration 50 ppm which give inhibition ratio 33.85 %. Also, the pencillin treatment gave better activity in the concentration 100 ppm which give inhibition ratio 70.494 % , while the concentration 50 ppm gave inhibition ratio 20.038 %.Based on the results of the experiment of immersion tomato roots with gibberellic acid at the concentration 100 ppm was the best, giving inhibition ratio 52.03 % while the 50 ppm of gibberellic acid gave inhibition ratio 26.89 %. Furthermore, when treating the tomato plant with pencillin the resistance against virus was higher at the concentration 100 ppm than at the concentration 50 ppm, which resulted in the inhibition ratios 63.60 % , 41.59 % respectively.The experiment of immersion Datura roots with gibberellic acid and pencillin showed no differences between the concentration 50 ppm of gibberellic acid and control. However, the 100 ppm of gibberellic acid gave inhibition ratio 53.76 %. This experiment did not identify any differences between the antibiotic pencillin concentrations, where the concentration 100 ppm of pencillin gave the highest resistance in plant against the virus with the lowest local lesions on Datura plant (inhibition ratio, 66.267% ) compared with the concentration 50 ppm which gave inhibition ratio, 21.881% and control.