PROGRESS IN THE BREEDING OF NOVEL INTERSPECIFIC ACTINIDIA HYBRIDS

Wild relatives of kiwifruit are a potential source of genetic diversity for characters that are absent from the cultivated species, Actinidia deliciosa and A. chinensis. Interspecific hybridization now forms part of the breeding strategy to combine novel characters such as a range of skin and flesh colours, ripening indicators, and the unique flavour of wild species with the large fruit size and postharvest storage of cultivated kiwifruit species. Many of the wild species of interest are tetraploid. Hybrid populations have been created between many of these tetraploid species and genotypes of tetraploid A. chinensis. Sterility of the F1 interspecific populations has occurred, and breeding strategies to circumvent this barrier to progress are discussed. However, despite the sterility problems, promising novel hybrid genotypes have been produced which have a kaleidoscope of colours, flavour, fruit size and fruit shape. While none has commercial potential in its own right, together they form the germplasm base from which further novel interspecific hybrid populations are being developed.