STABILITY OF RED FLESH COLOR IN KIWIFRUIT: FROM BREEDING TO POSTHARVEST

Abstract

Red flesh color is an important trait for kiwifruit. Red-fleshed kiwifruit have a strong market appeal because of their novelty, visual attractiveness and good taste. In recent years, red-fleshed kiwifruit have been an active area of our research, from breeding to cultivation and postharvest. In our breeding studies, three populations of seedling progenies of different red-fleshed female parents Actinidia chinensis var rufopulpa were examined; only a small proportion (0 to 14%) of plants had fruit with red flesh color, while the majority of plants had fruit with green or yellow flesh. During cultivation, expression of red flesh color is markedly affected by environmental factors. Higher altitudes, CPPU application, and older plant age are favorable for red flesh color development. Postharvest conditions are also found to affect the stability of red flesh color. Translocation of fruit from cool storage to ambient condition seems to enhance red color degradation. Our studies indicate that red flesh color of kiwifruit is rather unstable. Systematic studies are needed to reveal the genetic, biochemical and physiological basis of red flesh color formation and degradation, to develop cultivation and postharvest protocols, and to breed new cultivars for stable red flesh color development.