Kiwifruit: Evolution of a Crop

The kiwifruit of international trade are large-fruited selections of Actinidia chinensis and A. deliciosa. The two species occur naturally in China but until recently were not cultivated there. They are amongst the most recently domesticated of fruit crop species and they provide a classic example of the processes involved in taking a wild plant through to a commercially cultivated crop. Almost every single step in the domestication of A. deliciosa over the last 100 years is known in detail and the domestication of A. chinensis has occurred within living memory, within the past 40-50 years. This provides an unusual opportunity to study some of the factors influencing the domestication of a crop plant. Cultivation of A. deliciosa was initially successful only in New Zealand and expansion of exports was helped by successful marketing strategies and by sustained promotion. One cultivar, 'Hayward', proved to be the most popular in overseas markets, largely because its fruit withstand prolonged storage better than those of the other cultivars then available. The success of the New Zealand industry encouraged growers in other countries to grow kiwifruit and they also adopted 'Hayward'. Today, 'Hayward' accounts for about 60% of the kiwifruit grown commercially and 90% of the kiwifruit traded internationally. Successful domestication of A. chinensis has occurred more recently, starting in China. A cultivar of A. chinensis with yellow fruit flesh, 'Hort16A', developed in New Zealand, is the second kiwifruit cultivar to become important in international trade. Over the past ten years consumers' perceptions of kiwifruit have therefore changed. No longer are all kiwifruit hairy on the outside and green inside. Other cultivars with yellow, green or red fruit flesh or with distinct flavours are now being evaluated or grown. Priorities in breeding new kiwifruit cultivars are discussed, as are some of the important innovations that have aided the expansion of kiwifruit internationally.