Changes in the alkaloid content of developing fruits of tomato (Lycopersicon esculentum Mill.): II. Effects of artificial acceleration and retardation of ripening

Fruit ripening in normal red-, orange- and yellow-fruited cultivars of tomato was accelerated by treatment with Ethrel and such fruits had lower tomatine levels than untreated controls. Fruits in which ripening was retarded by incubating under reduced pressure had higher alkaloid levels than controls. In each case, fruit ripeness (as measured by pigmentation) showed a strong negative correlation with fruit tomatine. Ethrel treatment of fruits of the non-ripening mutants nor and rin caused only a small development of carotenoid pigment but markedly enhanced tomatine disappearance. Pigmentation and tomatine were again negatively correlated although the quantitative relationship differed. Under normal circumstances, tomatine disappearance from tomato fruits-is apparently governed by the physiological (cf. chronological) age of the fruit rather than by its growth or ripening characteristics alone.