Genetic resources of about 20 kinds of fruit trees have been introduced from both the tropics and subtropics to Japan. These plants can be grown in areas extending from 38° to 25°· North latitude. Some of them can be commercially cultivated through the application of advanced technology relating to the utilization of genetic resources, as well as breeding methods.
The distribution of these plants in the country varies according to the geographical and socio-ecological conditions. Citrus genetic resources were introduced from China to the temperate region 1900 years ago and thereafter, many species have also been introduced from other countries to Japan. In the coastal areas, a large number of citrus trees are being grown. Citrus fruits have been the most important fruit crops for a long time. Fresh fruits and canned products are now being exported to many countries.
Longan, litchi, banana and guava from China have been cultivated in the southwestern part of Japan for 450 years. Loquat was also introduced from Southern China to the western part of Japan from 1830 to 1847, pineapple has furthermore been cultivated in the subtropical zone for 130 years.
Barbados cherry, avocado, passionfruit, papaya, mango, carambola, wax apple, atemoya and canistel have been recently introduced and are ·grown in greenhouses or in fields in open air in areas along the coastal belt around the Pacific Ocean and East China sea.
Fruits are consumed locally, while several species are cultivated commercially and are costly fruit crops. In areas of the Seto inland sea and temperate zone, olive, feijoa and cherimoya have been commercially cultivated, recently. Pomegranate and jujube are predominantly grown in cold and temperate regions. Fruits are popular for consumers and there has been a large demand for selected exotic fruits for a long time in Japan.