Integration of transcriptomic and metabolomic data reveals new tetraploid kiwifruit hybrids with enhanced nutrients

Compared to traditional diploids, polyploid red-fleshed kiwifruit varieties usually present excellent character-istics such as larger fruit, storage resistance and strong stress resistance. In this study, the male seed progeny of the wild red-fleshed tetraploid germplasm, 'FXJX-CK-04137' (04137), was crossed with the tetraploid yellow -fleshed kiwifruit 'Jinshi 2' (J2). Two lines (Line O5D and Line 11E) were filtered out with excellent appear-ance quality from thirty F1 progenies. The phenotypes are stably inherited with big and red-fleshed fruit by progeny analysis for several years. The transcriptome and metabolome of fruit of both lines and their parental lines were integrated and analyzed to pursue nutritional qualities. The result shows that both F1 hybrids are rich in flavonoids, carotenoids and vitamin C, making them good candidates for new tetraploid varieties. Ultimately, our data indicate that using tetraploid kiwifruit varieties is an efficient way to breed new commercial varieties with enhanced nutrition.