Study On Systematic Taxonomy Of Chinese Ziziphus By RAPD And SRAP Markers

Ziziphus Mill. is the most economic value among Rhamnaceae. Ziziphus Mill.Classification research can trace back to early in the eighteenth century, but always sincethen the Ziziphus Mill. Classification problems last more confusion, once having 40species, 60 species, and 100 species etc. different ideas, and do not know if it is natural. 14species of Ziziphus and varieties of Z. jujuba Mill. in china were analysised using RAPDand SRAP molecular markers. The aim of this paper is to discuss the phylogeny. The mainresults were as follows:1. The effect of total DNA extraction from mature leaves of Ziziphus jujuba Mill.were studied under three kinds of conditions for sample storing(frozen at -20℃and -70℃,dried with silica gel) with DNA extraction methods of CTAB, high salt precipitation,and high salt and low pH method. The results showed that high-quality DNA can beobtained with all the three kinds of methods, and the purity of DNA extracted with highsalt precipitation method was the best, and then the low pH method. But the yield of DNAwith high salt precipitation method was the lowest. The purity and yields of DNA extractedfrom the leaves preserved in silica were not significantly different with fresh leaves.Storing in silica gel was suitable for sampling from open country or far away place.2. The optimal SRAP-PCR system in jujube was established with orthogonal design.In a total volume of 20μL SRAP-PCR system, it contains 1×buffer, 200μmol/L dNTP,30ng Primer, 2.5mmol/L MgCl₂, 1.0U TaqDNA polymerase and 20ng template DNA. Thesuitable PCR procedure was initially denaturing at 94℃for 5min; then 94℃, 1min, 33℃,1min, and 72℃,1min for the first five cycles; then the annealing temperature was raised to53℃for another 30 cycles. The new established SRAP-PCR system of jujube was fullyreproducible and good stability.3. Available 921 RAPD bands were generated by 31 primers in 26 samples of which919 were polymorphic. UPGMA method cluster analysis of RAPD indicated that all typescan be divided into seven kinds in genetic similarity 0.77, The first group was Z.pubinervis Rehd. gathered alone; The second group included Z. incurve Roxb, Z. attopensisPierre., Z. apetaia Hook., Z mauritiana Lam., Z. fungii Merr., and Z. rugosa Lam.; Thethird group included P. spina-christi Mill. alone; The fourth group gathered Z. jujuba Mill., Z. spinosa Hu. and varieties of Z. jujuba Mill.; The fifth group included Z. mairei Dode, Zxiangchengensis Y. L.Chen et P. K.Chou and Z. montana W.W. Smith. The sixth andseventh group were Z. oenoplia Mill. and Z.laui Merr. separately.4. 580 SRAP bands were generated by 19 primers in 26 samples of which 570 werepolymorphic. UPGMA method cluster analysis of SRAP indicated that all types can bedivided into five kinds in genetic similarity 0.75, The first group were Z pubinervis Rehd.,Z. incurve Roxb, Z. attopensis Pierre., Z. apetaia Hook., Z. mauritiana Lam., Z. fungiiMerr., and Z. rugosa Lam.; The second group included P. spina-christi Mill. alone; Thethird group gathered Z. jujuba Mill., Z. spinosa Hu. and varieties of Z. jujuba Mill.; Thefourth group included Z. mairei Dode, Z. xiangchengensis Y. L.Chen et P. K.Chou and Z.montana W.W. Smith; The fifth group were Z. oenoplia Mill. and Z. laui Merr.5. The synthetical analysis of RAPD and SRAP showed that: Z. jujuba Mill. and Z.acidojujuba C. Y. Cheng et M. J. Liu belonged to a species; Z. xiangchengensis Y.L.Chenet P. K.Chou and Z. montana W.W. Smith belonged to a species; The relationshipsof Z. mairei Dode, Z. xiangchengensis Y.L. Chen et P.K. Chou and Z. montana W. W.Smith were close, which may originate from same ancestry; The genetic similarities of Zattopensis Pierre. and Z. apetaia Hook., or Z. fungii Merr. and Z. rugosa Lam. were high.The varieties of Z. jujuba Mill. had the fruit or branch variations with Z .jujuba Mill., andthese variations were not belonged to variety. Under the species of Z. jujuba Mill. was notsuitable to set up varieties.