Possible Ancestor of Japanese Persimmon (D. kaki Thunb.) Existing in Yunnan Province and Northern Vietnam

Japanese persimmon or simply persimmon (Diospyros kaki Thunb.) is cultivated for a long time in China, Korea and Japan, and is a quite important fruit crop in East Asia.  However, the ancestor of persimmon is not clarified until now.  There is only one report in 1978 for speculating an ancestor of persimmon by Ng (Malaysian Forester 41:43-50), in which he proposed D. roxburghii (syn. D. glandulosa) as a possible ancestor. Persimmon is hexaploid with a few exceptions of nonaploid cultivars and distributes in temperate zone, while wild relatives of the same genus are mainly diploid and distribute in tropical and subtropical regions.  This proposed species, D. glandulosa, distributes in tropical to subtropical regions in Indochina and demonstrated to be diploid.  As the first stage, we organized several survey trips in Thailand between 1992 and 2001 for collecting some Diospyros species including D. glandulosa, and elucidated phylogenetic relationships among these collected wild species to D. kaki.  As the results, the relationships of these species are not close enough to D. kaki and we felt that we should collect wild relatives in subtropical and temperate regions in East Asia to obtain closer species to D. kaki.  So, as the second stage, we started the survey trips in southern China since 2008 and collected an interesting individual until now.  This individual is found in Xishuangbanna of Yunnan Province, China, and called “ye-mao-shi” in Chinese.  The morphology of fruit in this individual is just like D. kaki, except that the fruit skin is pubescent in contrast with glabrous skin for D. kaki.  Currently, we are looking for the species related to “ye-mao-shi” in northern Vietnam and collect several individuals in northern Vietnam.  In this presentation, we will discuss the relationships of these individuals collected in southern China and northern Vietnam to D. kaki, especially using the sequence analysis of matK gene of the chloroplast DNA.