Unravelling the physiological basis of superficial scald in pears based on cultivar differences

Abstract

Superficial scald is an important physiological disorder affecting both apple and pear fruit during postharvest storage. To date, superficial scald has been associated to many different preharvest and postharvest factors which are ultimately affected by the genetic characteristics of each cultivar. Accordingly, this work investigated differences in scald susceptibility during cold storage in two different pear cultivars ‘Beurré d’Anjou’ and ‘Packham Triumph’ and its relation to the changes in ethylene production, accumulation of α-farnesene and in its oxidation products (CTols), and finally changes in the fruit antioxidant potential and ascorbate levels. Collectively the results from this study indicate that superficial scald in pear develops differently than in apples. The highest sensitivity observed in ‘Beurré d’Anjou’ pears was not related to ethylene and/or to the capacity of the fruit to accumulate α-farnesene, but rather to its capacity to prevent the accumulation CTols. Although presenting similar values in global antioxidant potential, the higher resistance of ‘Packham Triumph’ pears to superficial scald was positively associated to higher ascorbate levels. The potential involvement of ascorbate in preventing superficial scald development is further discussed.