Survey of wound-induced ethylene production by excised root segments

Ethylene production was measured from excised 10-mm apical and subapical root segments from 50 cultivars in 19 species of 7 families. Monocotyledonous species tended to have much lower rates of ethylene production than dicotyledonous species. Ethylene production was generally higher in apical root segments than in subapical segments within 1 h of wounding. However, cultivars of Cucumis melo , C. sativus , Helianthus annuus , Hibiscus esculentus , and Zea mays had higher rates of ethylene production from subapical segments. In apical root segments, Phaseolus aureus cv. Berken had the highest ethylene production rate (76.7 ηl g^?1 h^?1), while Zea mays cv. Silver Queen had the lowest rate (0.6 ηl g^?1 h^?1). In subapical root segments, Cucumis sativus cv. Armenian had the highest rate (55.7 ηl g^?1 h^?1), while Zea mays cv. Silver Queen again had the lowest rate (0.6 ηl g^?1 h^?1). The many different responses in magnitude and kinetics of wound-induced ethylene production among the species, cultivars and tissues should provide interesting and useful systems with which to study wound responses and induced ethylene production.