Analysis Of Genetic Diversity On Wild Rice Zizania Latifolia Of The Sanjiang Plain

Zizania latifoliain Turcz.is a kind of aquatic herbaceous plant, which lives in the edge of the rivers and the swamps. The base of the stem is infected by the Ustilago esculenta P. Henn forming into a kind of vegetable called water bamboo.Zizania latifoliain is one of the most common emergent species in East Asia, It has high value in the work of breeding. It is used as a kind of germplasm resources of Oryza sativa and water bamboo. Previously the Sanjiang plian connected thousands of shallow lakes which together formed a wetland system capable of sustaining a rich variety of aquatic plants. Usually, it is an ecologically important wetland plant and conspicuous component of freshwater wetland systems in the Sanjiang Plain. However, during the past several decades, the wetland habitat was increasingly heavily destroyed by human activity. We established an advanced SRAP-PCR reaction system for Z. latifolia. The genetic diversity and genetic structure of Zizania latifoliain which collected in sanjiang plain was also analyzed.We established an advanced SRAP-PCR reaction system for Z. latifolia using a single factor experiment with five impact factors, including DNA template, Mg2+, dNTP mixture, Taq DNA polymerase and primer. The 10μL reaction mixture contained 50 ng of genomic DNA template, 1μL of 10×Buffer,2 mmol/L of MgC12,0.20 mmol/L of dNTP,0.5 U of Taq DNA polymerase, and 0.7 umol/L of primers. Therefore, the established SRAP reaction system for Z. latifolia was reliable. The results provided mature technical support for evaluating genetic diversity and constructing genetic linkage maps of Z.latifolia.Using sequence-related amplified polymorphism (SRAP) markers, genetic variation and population structure were assessed in the nine Z. latifolia populations distributed along three rivers from the plain. We used the POPGEN program, HICKORY version 1.0 program, TFPGA, ARLEQUTN 2.0 and 2MOD to calculated and analyzed the date. Five primer combinations produced a total of 344 unambiguous bands of which 311 (90.41%) were polymorphic. A relative low level of genetic diversity (Pp=58.8%, He= 0.156,I= 0.244) was detected in Z. latifolia populations. The main factor responsible for that was its high degree of inbreeding in the reproductive system (FIS= 0.793), which probably resulted from mating events among close relatives even intraclones. The F-statistics calculated by different approaches consistently revealed a high genetic differentiation among populations, contributing about 30% of the total gene diversity. The evident population structure of Z. latifolia could be due to self-fertilizing reproduction, restricted gene flow and genetic drift. Estimates of gene flow by Fsrand coalescent-based simulation analysis indicated a restricted recurrent gene exchange among populations (Nm= 0.609, M= 0.600). Genetic drift played a more important role than gene flow in the current population genetic structure of Z latifolia because of its highly fragmented habitats. A conservation strategy for conserving all extant populations to maximize genomic representation of the species is recommended.