Recent persimmon cultivar composition and breeding activities in Japan
Persimmon production area is the third largest among tree fruit crop production areas in Japan. However, the value of persimmon production itself staggers at seventh place due to low market prices. Even though persimmon fruits export is increasing gradually, it remains at just 1% of the total value of production. Therefore, new cultivars that combine high consumer acceptance and long shelf life are needed for increasing both domestic consumption and exports. The production areas of the leading cultivars, Fuyu, Hiratanenashi, and Jiro and their bud mutants, are around 67% of the total persimmon production area in 2018. For 30 years or more, the areas of these three cultivars and their bud mutants have occupied more than 60% of the total persimmon production area. Since 1980, 66 new persimmon cultivars were registered as new cultivars under the Plant Variety Protection and Seed Act in Japan. Among those registered, only 23 were derived from crossbreeding. Moreover, 15 of the 23 cross-bred cultivars were released by the National Agriculture Research Organization. In contrast, there was only one cross-bred cultivar registered by private breeder. Recently, several prefectural official institutes started persimmon breeding programs with aims of breeding new high-quality pollination-constant non-astringent (PCNA) cultivars and have released some new ones. However, these new cultivars released by the official institutes were bred using cultivars released by the national institute as parents. As a result, genetic diversities of the source of PCNA breeding remains very narrow, which increases the risk of reduced yield due to inbreeding depression. Therefore, use of non-PCNA and Chinese PCNA as cross parents is still important for expanding the genetic variation in PCNA parental population in breeding. An enlargement of genetic variation in PCNA population and avoidance of inbreeding enable breeding new cultivars with high yield, in addition to high quality and long shelf life.
Sato, A. and Onoue, N. (2022). Recent persimmon cultivar composition and breeding activities in Japan. Acta Hortic. 1338, 1-6
cultivar registration, Diospyros kaki, fruit production, genetic improvement, market price