Genetic Variation Analysis of Chinese Jujube Cultivars Using ISSR Molecular Markers

Chinese jujube (Ziziphus jujuba Mill.) is an economically important species with over 4,000 years of cultivation history. Cultivar classification and phylogenetic relationship of jujube have been controversial due to the lack of data related to species origin and cultivation. In this study, inter simple sequence repeat (ISSR) markers were used to analyze the genetic characteristics and relationships of Korean and Chinese jujube cultivars. The amplification of genomic DNA of the 32 accessions using 11 primers yielded 149 amplified bands, of which 141 were polymorphic. The amplification of 22 jujube cultivars generated 76 bands, 40 of which were polymorphic, suggesting that many polymorphic bands appeared in the outgroup. The mean genetic similarity index (GSI) of the cultivars was 0.835; Bokjo, Geumseong, Wolchul, and Mudeung cultivars showed the highest GSI of 1, and Sandonglizao and Xiaolizao had the lowest GSI of 0.658. The cluster analysis resolved Indian jujube (Z. mauritiana Lam.) and Paliurus ramosissimus Poir. in a basal Group I, sour jujube 2 (Z. acidojujuba C.Y. Cheng & M.J. Liu) and Damaya formed Group II, Dabailing and Daguazao were clustered in Group III, and the remaining accessions formed Group IV. The Korean cultivars and Korean native varieties showed genetic uniformity and were close to some Chinese cultivars. Accordingly, exploration of domestic and foreign genetic resources should be supplemented with survey of characteristics of collected material for genetic resources management and breeding of elite lines.