Ethylene production by botrytis cinerea ( causal organism of gray mold disease)‎ and influence of the exogenously applied growth regulators and thier inhibitor on disease development

الملخص EN

The fungus Botrytis cinerea grown on shaking potato dextrose broth (PDB) medium amended with 10 mM methionine produced ethylene.

Ethylene production reached a peak after 4 days of incubation; however, there was a high variability in production between the isolates.

The range of ethylene produced by twenty four isolates of the fungus was from 383 to 6789 ?l/g/h with average production of 2091 ?l/g/h.

The results showed considerable intraspesific variation in ethylene production of B.

cinerea.

The role of exogenously applied ethylene (Ethephon®) in the interaction between B.

cinerea and tomato (Lycopersicon esculentum) and bean (Phaseolus vulgaris) plants was studied in vitro and in vivo.

Ethephon® has not significantly affected the fungus mycelium growth rate on potato dextrose agar (PDA), while it significantly increased disease severity by 50.4 % - 55.8 % on tomato plants and by 27.6 %-33.8 % on bean plants at concentration 200-600 ?g/ml.

Aminoethoxyvinylglycine (AVG) significantly decreased mycelium growth in vitro at 200 ?g/ml by 47 %, and it decreased disease severity by 45 %- 49 % at concentrations 200 - 300 ?g/ml on tomato plants and 55 % -75 % at 100-300 ?g/ml on bean plants.