Origin of the remaining Primula sieboldii individuals derived from an extinct population in Takayama

Abstract

Primula sieboldii E. Morren (Primulaceae) is an endangered species in Gifu Prefecture, Japan. There was once a wild population in Kiyomi, located in Takayama, Gifu. It is said that some individuals cultivated by people living in Kiyomi originated from the extinct Kiyomi population. In this study, we aimed to identify original genets in the Kiyomi population based on a questionnaire, a STRUCTURE analysis, and an assignment test based on DNA analysis. We detected 16 genets from 62 samples using eight SSR markers. Of the 16 genets, four (g2, g3, g4, and g6) likely originated from the Kiyomi population based on the questionnaire and their close genetic relationships. In the STRUCTURE analysis, these four genets had different genetic compositions. To examine whether the 16 genets originated from the extinct Kiyomi population, we performed an assignment test using the Takayama population, which is expected to be genetically close to the Kiyomi population. The assignment test assigned only g3 to the Takayama population, but the genet was not considered an original due to the very low probability. In conclusion, four genets were identified as likely original genets based on the questionnaire, but no positive proof was obtained from the DNA analysis following the extinction of the native population.