Analysis of the Genetic Relationships in Chinese Ziziphus with SRAP Markers

The phylogenic and genetic relationships in germplasm resources of Chinese Ziziphus were studied at molecular levels, for providing new molecular evidences of classification, protection, and utilization of germplasm resources of Ziziphus. The sequence-related amplified polymorphism (SRAP) was assessed to analyse the genetic relationships among 14 species of Ziziphus, 11 cultivars of Z. jujuba Mill., and one outgroup. A total of 580 DNA bands were amplified by 19 selective primers, 570 of which (98.28%) were polymorphic. The average number of polymorphic DNA bands amplified by each primer was 30. The genetic similarities of 26 sample materials were between 0.22 and 0.99. UPGMA method cluster analysis showed that 26 sample materials were classified into six cluster groups with the genetic similarity of 0.28. The results showed that SRAP technique is efficient in studying genetic relationships among Ziziphus, Z. jujuba Mill. and Z. acidojujuba C. Y. Cheng et M. J. Liu which should be treated as one species, and further infraspecific classification of Z. jujuba Mill. should be classified into two subspecies; the scientific names of new taxa, Chinese jujube, and wild jujube were Ziziphus jujuba Mill. subsp. jujuba and Ziziphus jujuba Mill. subsp. spinosa (Bunge) J. Y. Peng, X. Y. Li et L. Li, respectively. Z. xiangchengensis Y. L. Chen et P. K. Chou, Z. montana W.W. Smith and Z. mairei Dode might be originated from same ancestry. Z. xiangchengensis Y. L. Chen et P. K. Chou and Z. montana W.W. Smith should be treated as one species. The infrasubspecific taxon of Z. jujuba Mill. was not suitable to set up varieties.