1969 Volume 38 Issue 4 Pages 350-358
In the previous paper, it was proposed that the respiratory pattern in ripening process of harvested fruits should be classified in three types. The present paper reports the effects of endogenous and exogenous ethylene on ripening and respiration of fruits, in relation to the respiratory pattern. The materials used were as follows: tomatoes (Fukuju 2-go) and bananas (Musa sapientum L.) as the temporary rise (climacteric) type; strawberries (Dana), Japanese persimmons (Hiratanenashi and Jiro), and peaches (Hakuto, white flesh variety) as the late peak type; Satsuma oranges (Citrus unshiu M.) as the gradual decrease type.
(1) Color development of mature-green tomatoes was accelerated by externally applied ethylene, and the effect was more obvious with late-picked fruits than early-picked ones in the same field. Climacteric rise of respiration was hastened by the ethylene applied. When the mature-green tomatoes were stored, ethylene concentration in the fruits increased markedly during coloring, and a considerable level of ethylene was found prior to climacteric onset.
(2) Green bananas rapidly turned yellow by the ethylene application. Climacteric rise took place immediately, but the peak in the rate of carbon dioxide production was much higher than that of naturally occurred climacteric rise.
(3) When strawberries were treated with ethylene at the stage of turning to white (immediately before color appearance), developments of coloring and softening were not affected. On the carbon dioxide production of the fruits, also, no effect was found. Ethylene concentration in the fruits had reached to a considerable level at the atage of turning to white.
(4) Softening of peach fruits after harvest was not influenced by ethylene treatment, and little effect was found on carbon dioxide production. Ethylene concentration in the fruits was at considerably high level even at unripe stage.
(5) Japanese persimmon fruits were markedly affected by ethylene treatment. Softening and coloring of fruits which were treated at unripe stage occurred rapidly, and astringency was removed. Production of carbon dioxide increased sharply in ripe fruits as well as unripe fruits. Ethylene concenration in the fruits was generally at low level, but some increase was observed in soft fruits.
(6) Immature Satsuma orange were accelerated the coloring by ethylene application. Marked increase of carbon dioxide production occurred in both half-green and full-yellow fruits. When ethylene was removed with vacuum pump from the fruits of which respiration had increased by ethylene application, the carbon dioxide production lowered to the extent of non-treated fruits, being different from the fruits of climacteric class, and re-application of ethylene on these fruits induced increase of respiration again. Ethylene concentration in the fruits was generally at low level throughout the storage period.
(7) It seems that the effects of ethylene treatment depend on the endogenous ethylene concentration, and discrimination between the climacteric and others can not be made from the response to ethylene applied, when the fruits of the late peak type are included.
