Porat, R., Department of Postharvest Science of Fresh Produce, ARO, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Weiss, B., Department of Postharvest Science of Fresh Produce, ARO, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Zipori, I., Department of Fruit Tree Sciences, ARO, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Dag, A., Department of Fruit Tree Sciences, ARO, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel

The local guava (Psidium guajava) variety cultivated in Israel, named Ben Dov, emits a strong odor and suffers from a short postharvest life. To address these problems, we initiated a guava breeding program, and identified two new varieties, the pink-flesh King and the white/yellowish-flesh Omri, that have much better storage lives and emit fewer odors. Physiological characterization of their ripening process revealed that the traditional variety Ben Dov exhibited a classic climacteric behavior, whereas the new variety King had a suppressedclimacteric phenotype, and Omri was apparently nonclimacteric and did not exhibit any increases in respiration and ethylene production rates during ripening. Furthermore, differing concentrations of the ethylene action inhibitor 1-methylcyclopropene (1-MCP) were required to inhibit ripening in the various varieties: a high 1-MCP concentration of 500 nL·L -1 was required to delay ripening and to prolong postharvest storage life of the climacteric variety Ben Dov; a moderate concentration of 250 nL·L -1 inhibited ripening of the suppressedclimacteric variety King; and a low concentration of just 100 nL·L -1 was sufficient to inhibit ripening of the nonclimacteric variety Omri. The results of this study indicate that different guava varieties may pursue distinctive climacteric behaviors: the suppressed-climacteric variety and, to a greater extent, the nonclimacteric variety, have longer storage lives and are more sensitive to 1-MCP than the traditional variety.