Research On The Genetic Relationship Of Daodi Rheum In Gansu And Qinghai Via CpDNA Sequence

Daodi herbs are considered as high quality characterized with high quality and efficacy,unique processing method and high regionalism.So far,a lot of researches have been done on Daodi herbs of molecular identification,however the studies on the genuineness of Rheum were only focus on identifing the adulterants.The main productive Daodi regions of Rheum are in Gansu and Qinghai.Our study choosed 23 populations localized in main productive regions including 13 Rheum palmatum populations in Gansu,8 Rheum tanguticum populations Qinghai,1 Rheum palmatum population in Ningxia and 1 Rheum tanguticum population in Sichuan.We analized the genetic diversity and genetic relationship via cpDNA sequence including rpl32 and matk studying and evaluating the Rheum via degree of mutation,purity of germplasm resoures,adulterants companion planting and identification of affinity of populations in different regions.The results are summarized as follows:1.The sequencing length,the effective length and C+G% of rpl32 and matk sequence in Rheum showed no significant difference and the sequencing length were respective in 407-425 and 736-774,the effective length were respective 422 bp,430bp and 775 bp,788bp and the C+G% were respective in 25.17%-26.07% and 35.40%-36.00%.2.Analyzed the genetic diversity and genetic relationship of cultivated Rheum tanguticum via cpDNA sequences of rpl32 and matk.The results showed that:Thereinto,rpl32 and matk were the same haplotype of the 12 cultivated populations of Rheum palmatum in the southwest of Gansu and haplotype divisity and nucleotide diversity were 0 indicating that Rhuem palmatum populations cultivited in southwest of Gansu showed low mutation and high purification of germplasm resources and high consistency in different regions,and can be called Daodi“Xuanshui Rheum”.Rhuem palmatum in Zhangye existed two haplotypes.One was consisitent with southwest of Gansu and the other was not consisitent with Rheum palmatum indicating that Rhuem palmatum populations in Zhangye may mixed with fake stamp or other orign of germplasm.3.Analyzed the genetic diversity and genetic relationship of 9 Rheum tanguticumpopulations via cpDNA sequences including rpl32 and matk.The results showed that:The Rheum tanguticum had high degree of genetic variation,the haplotypes of rpl32 and matk sequence were 5 and 6,the Hd were 0.600 and 0.784,the Pi were0.00315 and 0.00346.The cultivated Rheum tanguticum in Menyuan,Huangzhong and Hongyuan had little genetic differences with the uncultivated Rheum tanguticum in Qinghai,and they had the same haplotypes;The cultivated Rheum tanguticum in Datong anh Huzhu had large genetic differences with the uncultivated Rheum tanguticum in Qinghai,and they had different haplotypes,showing that the degree of genetic variation in cultivated Rheum tanguticum populations were obviously higher than the degree of genetic variation in uncultivated populations caused by the cultivated Rheum tanguticum mixed with fake stamp or other orign of germplasm in Datong and Huzhu.4.Analyzed the genetic relationship of cultivated Rheum in different regiongs via DNA sequences of rpl32,matk and matk+rpl32,the results showed that:the cultivated Rheum palmatum in Zhangye mixed with Rheum officinale;The cultivated Rheum tanguticum in Huzhu mixed with Rheum officinale;The cultivated Rheum tanguticum in Datong mixed Rheum officinale and Rheum palmatum;The cultivated Rheum in Ningxia were Rheum undulatum.5.The rpl32,matk and matk+rpl32 sequence could not only be used as the candidate sequence of DNA barcoding on falsify identification,but also could be used as molecular markers on the identification of the purity of genetic resources.And the matk+rpl32 sequence had better identification effect on the identification of intraspecific genetic mutation than rpl32 and matk sequences.