Kiwifruit (Actinidia spp.) in Italy: The history of the industry, international scientific cooperation and recent advances in genetics and breeding

In this review we give an account of the introduction of kiwifruit to Italy and the development of the industry, that in the 1990s became the world-leading player. Although kiwifruit were known in Italy since the 1930s as ornamental plants, the first kiwifruit orchards were established in Italy in the late 1960s, after several articles appeared in the French popular literature. Most kiwifruit plantings are still of the cultivar 'Hayward' but there are now orchards of several new cultivars, including the yellow-fleshed ones, while the baby kiwifruit (A. Arguta) plays a marginal role. The Italian kiwifruit industry makes up only a small part of Italian horticulture in general, but is nevertheless profitable and still expanding, after the small contraction in recent years owing to the spread of bacterial canker of kiwifruit. The orchard management has evolved as follows: the plant density has increased, owing mainly to the reduction of within row spacing from 6.0 to approx. 2.0 m; pergola and the T-bar has become in a few years the most popular training systems; the ratio of pollenizers: females has changed from 1:7-15 to 1:1-3, while artificial pollination is being generally adopted. Yields can vary from 30 to 60 t/ha according the cultivar, training and pruning and the use of plant growth regulators. The presence of leading kiwifruit scientists in New Zealand, the country that first domesticated the kiwifruit, led to an intense exchange of researchers between the two countries, promoted by the Plant & Food Institute of New Zealand and the Universities of Bologna and Udine, while the contact with Chinese scientists developed later, in some case encouraged by common research projects funded by the European Union (EU). Several Italian scientists have developed personal contacts with kiwifruit scientists of most kiwifruit growing countries. Studies on genetics of kiwifruit were initiated by the New Zealand breeders of DSIR and stimulated the development of breeding programs in New Zealand, followed on smaller scale in other countries, such as France, Italy, Japan, Korea and Chile. The development of linkage maps allowed the mapping of traits of interest and the development of the so-called marker-assisted selection (MAS). The release of EST database by the New Zealand scientists and the publication in 2013 of the kiwifruit genome sequence by Chinese scientists offered new tools for the MAS of agronomic traits and offered as well the opportunity to study biochemical pathways of the synthesis of flesh pigments, fruit aromas and other traits, now introduced into modern breeding programmes. In this review I give a brief account also of the success in promoting exchange of expertise and scientists within the kiwifruit community.