Author
ZHEBENTYAYEVA, TATYANA - Clemson University | |
SHANKAR, VJAY - Clemson University | |
Scorza, Ralph | |
Callahan, Ann | |
RAVELONANDRO, MICHEL - Bordeaux University | |
CASTRO, SARAH - University Of California, Davis | |
DEJONG, TED - University Of California, Davis | |
SASKI, CHRISTOPHER - Clemson University | |
Dardick, Christopher - Chris |
Submitted to: Horticulture Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 9/12/2018 Publication Date: 1/1/2019 Citation: Zhebentyayeva, T., Shankar, V., Scorza, R., Callahan, A.M., Ravelonandro, M., Castro, S., Dejong, T., Saski, C.A., Dardick, C.D. 2019. Genetic characterization of worldwide Prunus domestica (plum) germplasm using sequence-based genotyping. Horticulture Research. https://doi.org/10.1038/s41438-018-0090-6. DOI: https://doi.org/10.1038/s41438-018-0090-6 Interpretive Summary: Prune plums are a distinct species of tree (scientific name Prunus domestica) that has been bred and cultivated for at least several millennia. There are thousands of prune plum varieties available to growers, many of which were developed centuries ago. Yet in the US, the plum variety ‘Improved French’ accounts for >99% of all prune production. These various plum varieties have been classified into a handful of types or groups according to their physical characteristics such as fruit size, color, useage, and regional history. However, the origin of the species Prunus domestica as well as the genetic relationships of the various plum groups and important commercial varieties such as ‘Improved French’ are currently unknown. Here we performed a comprehensive genetic study for over 400 plum varieties collected from around the world. The results showed that prune plums are a highly inbred species and fall into only 4 distinct genetic groups that are very closely related to at least two other wild plum species. The data support the notion that Prunus domestica is not naturally occurring and was likely the consequence of cross breeding between at least two wild plum species by early Eurasian agricultural societies. Technical Abstract: European plum (Prunus domestica) is a hexaploid fruit tree species cultivated around the world. Locally it is used for fresh consumption and the production of spirits while commercially the fruit is primarily sold dried (prunes). Despite its agricultural importance and long history of cultivation, many questions remain about the origin of this species, the relationships among its many pomological types, and its underlying genetics. Here, we used a sequence-based genotyping approach to characterize worldwide plum germplasm including the potential progenitor Eurasian plum species. Analysis of 405 DNA samples established a set of four distinct clades consistent with the pomological groups Greengages, Mirabelles, European plums, and d’Agen (French) prune plums. Overall, there was relatively low genetic diversity across all cultivated plums suggesting they have been largely inbred and derived from a limited number of founders. The results support P. domestica having originated as an interspecific hybrid of a diploid P. cerasifera and a tetraploid P. spinosa that itself may have been an interspecific hybrid of P. cerasifera and an unknown Eurasian plum species. The low genetic diversity and lack of true wild-types coupled with the known cultivation history of Eurasian plums imply that P. domestica may have been a product of inter-specific cross breeding and artificial selection by early agrarian Eurasian societies. |