Persimmon

Abstract

Diospyros kaki Thunb., the Oriental persimmon originated and was domesticated in Eastern Asia where many indigenous cultivars exist. Ninety percent of the worldwide production in 2006 is in China, Korea, and Japan. The largest producers outside Asia are Brazil, Israel, Spain, and Italy. Persimmon is classified into nonastringent and astringent cultivars depending on whether the fruit loses astringency on the tree at maturity. Astringency is caused by water-soluble tannins found in large "tannin" cells, which are scattered throughout the fruit flesh. Drying after peeling, treatment with carbon dioxide gas or ethanol vapor changes these soluble tannins into insoluble forms so that astringent fruit becomes nonastringent. The persimmon cross-breeding program at the national institute in Japan has been continuing since 1938, and has released 11 nonastringent and two astringent cultivars, including nonastringent ones with high eating quality, and with both early ripening and noncracking. There are breeding programs in Korea, Italy, and Spain. The current goals of breeding are: nonastringency, fruit quality and appearance, fruit ripening time, postharvest conservation, productivity, and disease and pest resistance. Due to the hexaploid nature of the persimmon, linkage maps are not available but molecular markers for nonastringency have been developed. The MAS for nonastringency is going on practically and effectively in Japan. There are a few reports of genetic transformation of persimmon using Agrobacterium tumefaciens.