Effects of Wounding on Respiration and Ethylene Production by Cantaloupe Fruit Tissue.

Despite the difficulty of evaluating the effects of handling and wounding, tissue slices offer a(lvantages for physiological or biochemical tests where small quantities of uniform tissues are required. This paper provides information on behavior of tissue slices from cantaloupe fruits, including the changes induced by wounding. Respiration, ethylene production, and the effect of applied ethylene on respiration were measured, and the responses of tissue slices from cantaloupe fruits of various chronological ages were compared with the responses of matched intact fruits. It is well-known that wounding of plant tissue increases the rate of respi ration (1, 5, 16), and may induce chemical changes an(l meristematic activity in the region of the wound (2, 3). Even shaking or dropping can cause an increase in respiration in avocado and citrus fruits ( 1, 9). -Much information has been accumulated on changes in tissue cut from tubers and tuberous roots (12, 13, 15), but information on cut or wounded tissue from fruits is limited. The response of fruit tissues to wounding is variable and is influenced by variety and maturity (1, 10, 19, 20, 24). Other sources of variability are fruit size, morphology, and the permeability of the peel to gases. According to various authors ( 1, 10, 22), increased CO2 evolution soon after cutting may indicate improved ventilation of the organ, rather thani a direct effect of the wound on the cells involved. At least part of the burst of CO., produced by apples inmnmediately after cutting, may be eliminated by pre-evacuation of the tissue (5). Studies by Burg and Thimaun (7) andI Burg (5) emphasized the importance of the time elapsed after cutting in interpreting the effects of wounding. Cutting or wounding generally causes increased production of ethylene and other volatiles by fruit tissue (11, 18). However, although Burg and Thimnanli (7) found an increased respiratory rate in tissues cut from postcliniacteric apples, the rate of ethylene production xw as the same in plugs of tissue