The Phylogenetic Relationship Research And Seeds' Detection Of 6 Related Species In Sorghum By Using Molecular-Marking Techniques

DNA in six related species in Sorghum was isolated by using four methods including CTAB, SDS, CTAB-SDS and TaKaRa DNA extraction kit for GMO Detection. The purity, concentration and extraction ratios of DNA in the products obtained by different methods were tested respectively. Results showed that CTAB-SDS was the best method to extract the genomic DNA in the six species of the four methods.Analysis of phylogenetic and evolution in 6 species of Sorghum was based on internal transcribed spacer (ITS) sequences in nuclear ribosomal DNA. Results showed that the length of ITS regions among the 6 species ranged from 588bp to 589bp and the contents of G+C in ITS (ITS1+5.8S+ITS2) regions ranged from 60.27% to 61.05%. The length of ITS1 ranged from 207bp to 208bp and the contents of G+C in ITS1 regions ranged from 53.91% to 61.54%. The length of 5.8S rDNA and ITS2 regions in the 6 species was 164bp and 217bp respectively, and the contents of G+C ranged from 56.10% to 58.54% in 5.8S rDNA region and 66.36% to 67.28% in ITS2 region. Among regions of ITS, ITS1, ITS2 and 5.8S, the best sequence for genetic relationships analysis in the 6 species was ITS region. On the basis of the Jaccard coefficient, S. sp. is more related to S. propinguum than to other species. This is consistent with the fact that S.sp. is derived from S. propinguum. Therefore, the taxonomic status and quarantine status.The PCR amplified 18S-26S fragments were analyzed by restriction endonuclease digestion (RFLP). Results showed that the restriction maps of PCR product were different from each other. S. halepense (L.) Pers can be identified by Nae I -PmaC I or AfIlll, and S. silk by Xce I . S. sp. by BspH I , and S. sp. and S. propinguum can be differentiated from other species by Cfr I.