Identification of climacteric and nonclimacteric phenotypes of Asian pear cultivars by CAPS analysis of 1-aminocyclopropane-1-carboxylate synthase genes

The maximum level of ethylene production is closely related to fruit ripening and storage potential in Asian pears. In a previous study, we identified two markers (A and B) linked to high and moderate ethylene production during fruit ripening, respectively, by restriction fragment-length polymorphism analysis of two 1-aminocyclopropane-1-carboxylate (ACC) synthase genes (PPACS1 and PPACS2). In this study, a total of 152 cultivars were categorized into four marker types (AB, Ab, all, and ab); types AB and Ab show high levels, aB a moderate level, and ab a low level of ethylene production during fruit ripening. A large number of ab and all cultivars but few AB and Ab cultivars were observed. It suggests that there has been a decrease in high ethylene producers by artificial selection because of short shelf life. The ab cultivars are a good genetic resource for production of new cultivars with a long shelf life. Such information on marker types is useful for breeding strategies aimed at improving storage ability in Asian pears.