The Role of Anaerobic Respiration in Germinating Muskmelon Seeds

Abstract

Exposing muskmelon (Cucumis melo L.) cultivar seedlots to N₂ atmosphere created totally anaerobic conditions which stimulated ethanol production and accumulation in both high and low vigour seeds. However, accumulation of ethanol was consistently higher in the low vigour seeds than in the high vigour ones. In addition, CO₂ production under N₂ and in air suggests the presence of an apparent ‘Pasteur effect’ in the low vigour seeds but not in the high vigour seeds. Acetaldehyde production under N₂ was very low and did not seem to be associated with seed vigour, probably because of its nature as an intermediate in ethanol production. The fast shift toward ethanol may be due to the fact that alcohol dehydrogenase, the enzyme which catalyzes the conversion of acetaldehyde to ethanol, exists in sufficient amounts in the imbibing seeds so that it is not a limiting factor in the conversion to ethanol. Alcohol dehydrogenase activity did not appear to be related to seed vigour.