Microbial Induced Ethylene Synthesis as a Possible Factor of Square Abscission and Stunting in Cotton Infested by Cotton Fleahopper1, 2

Abstract

Excised terminal buds of cotton, Gossypium hirsutum L. cv. Stoneville 7A, infested with cotton fleahopper, Pseudatomoscelis seriatus Reuter (Hemiptera: Miridae), produced considerably more ethylene than noninfested controls. The insect itself did not produce any ethylene. A bacterium and 3 fungi were isolated from fleahopper-infested buds which were producing ethylene. Terminals inoculated with these micro-organisms in the absence of insects produced ethylene at rates equivalent to those obtained with a fleahopper infestation. It is postulated that the cotton fleahopper inoculates the buds with micro-organisms which promote ethylene production by the tissue, or produce ethylene themselves, or both. The ethylene so produced might contribute to the inhibition of internode elongation and the abscission of small flower buds which are associated with fleahoppers.