Geographical distribution and morphological diversity of red-fleshed kiwifruit germplasm (Actinidia chinensis Planchon) in China

The fruit flesh color of kiwifruit (Actinidia chinensis) is generally green or yellow when ripened. Developing kiwifruit cultivars with new fruit flesh color such as red-fleshed color has stimulated much interest for kiwifruit breeders and researchers recently due to its potentially importance for meeting the increasing and changing markets and consumers. In the present study, the whole geographical distribution and morphological variation of wild red-fleshed kiwifruit in China were investigated. In total of 56 accessions of red-fleshed kiwifruit were found across 19 separated localities, representing different ecological and climatic conditions throughout South and Central China. Characterization of nine horticulturally important fruit traits of all accessions showed that there are extensive variations in fruit shape, fruit hairs and as to red intensity, spread of the red pigments and background flesh color. The results presented here have updated the current knowledge on the natural distribution and ecological adaptation of wild red-fleshed kiwifruit resource, which should be valuable for kiwifruit agriculture such as the determination of planting areas of red-fleshed kiwifruit cultivars. The accessions with extensive morphological variation can also contribute to kiwifruit breeding in future such as developing new cultivars with red color flesh.