Role of Plant Growth Regulators in the Interaction Between Botrytis Cinerea and it's Host Plants

Role of Plant Growth Regulators in the Interaction Between Botrytis Cinerea and it's Host Plants

Khaled Mohammed Ibrahiem Hardan The role of plant growth regulators in the interaction between Botrytis cinerea and tomato (Lycopersicon esculentum) and bean (Phaseolus vulgaris) plants was studied in vitro and in vivo. Naphthalene acetic acid (NAA) significantly decreased mycelium growth rate on PDA amended with 125 ~g/ml. On the other hand, it significantly increased grey mould disease severity on tomato at concentrations more than 600 [g/ml. NAA had no effect in the disease severity on bean plants at the same concentration, and also decreased the disease on tomato and bean detached leaves at 300 gg/ml. Gibberellic acid (GA3) had no effect the mycelium growth rate on PDA, whereas it increased disease severity on tomato and bean plants at 500 gg/ml. Ethephon (Et) did not significantly affect mycelium growth rate on PDA, while it significantly increased the disease severity at 500 gg/ml in both hosts. Methyl jasmonate (MeJa) significantly decreased mycelium growth rate on PDA at 150 gg/ml, increased disease severity at high concentrations (more than 300 gg/ml) in tomato plants, while it decreased the disease severity in bean plants at the same concentration. The ethylene inhibitor aminoethoxyvinylglycine (AVG) significantly decreased mycelium growth in vitro at 200 gg/ml, and it decreased disease severity on tomato and bean plants at 300 [Lg/ml. Abscisic acid (ABA) significantly decreased mycelium growth in vitro at 200 gg/ml, while at low concentrations up to 150 [tg/ml it increased the disease in vivo. Ethylene was produced by the fungus B. cinerea growing on shaking PDB-amended with 10 mM methionine. Ethylene production reached a peak of 2000 gl/g/h after 4 days of incubation. However there is a high variability in ethylene production between the strains. Khaled Mohammed Ibrahiem Hardan Supervisors Prof. Mohammed S. Ali- Shtayeh Dr. Radwan Barakat July 2000 Zajel / An-Najah National University