EFFECT OF ESSENTIAL OILS ON ETHYLENE PRODUCTION AND ACC CONTENT IN APPLE FRUIT AND PEACH SEED TISSUES

The inhibitory effect of different essential oils on ethylene biosynth esis was investigated by using apple (Malus domestica Borkh. cv. Tsuga ru) fruit and young peach (Prunus persica Batsch. cv. Nishino-hakuto) seed tissues. Apple tissues retain a high ethylene-producing capacity, whereas young peach seeds begin to produce ethylene rapidly after bei ng removed from the pits. A more pronounced inhibition of ethylene bio synthesis by the oils was noted in peach seed than in apple fruit tiss ue. Linalool, citral, citronellal, and 1-octanal inhibited ethylene pr oduction in apple fruit tissues by 50 to 72% over the range of 3.6 to 36 nl . ml(-1); citronellol, geraniol, 1-nonanal, beta-pinene, p-cymen e, and alpha-pinene were less inhibitory of ethylene production. In th e peach seeds, the aldehyde group of essential oils inhibited ethylene production and concomitantly suppressed the increase in ACC content b y 98 to 100%; alcohol and hydrocarbon groups were less suppressive. Mo st of the essential oils, especially the aldehyde group, seem to inhib it ethylene production by suppressing ACC synthesis.