Abstract
There is increasing interest in fruits of bramble crops (Rubus spp.) because of the possible benefical health effects associated with their phenolic content. Almost all cultivars are from Europe and the United States, although there are many wild Rubus species native to Japan. In order to obtain basic knowledge for the horticultural application of those wild species, we collected and evaluated some wild species native to Kyusyu Island as genetic resources. All raspberry cultivars were diploid, but almost all wild species were diploid with a different genome size, except for a few hexaploids. The aggregate fruit weights of wild species were not smaller than cultivars except for Rubus lambertianus Seringe. The ripening fruits of some wild species, R. crataegifolius Bubge., R. trifidus Thunb., and R. palmatus Thunb., were higher than the fruits of raspberry cultivars regarding total sugar contents and lower in total organic acid contents. The fruits of R. crataegifolius Bubge., R. palmatus Thunb., and R. lambertianus Seringe also showed a higher total polyphenol content and antioxidant activity than the cultivars. Some wild species native to Japan may be useful as breeding material to establish some new cultivars adaptable to Japan with high quality and functionality.
