Study On The Identification Of Davallioid In Yunnan

Rhizoma drynariae is widely used in Traditional Chinese Medicine(TCM),whose functions include tonifying kidneys,strengthening the muscles and bones,reunion of the fractioned tendons and bones while relieving the pain.It is an important crude material in the formulas of orthopedics and traumatology in TCM.Drynaria fortunei is documented in the Chinese Pharmacopoeia(published in 2015)as the origin plant of rhizoma drynariae.Besides that,there are many medicinal ferns which,due to the similarities in morphology,functions,names,local traditions,and even adulteration,have mistakenly become the origin plants of rhizoma drynariae,thus caused serious problems in the quality control and drug safety.Based on the facts that most of the confusing medicinal materials of rhizoma drynariae(Davallioid)are found,and centrally distributed in Yunnan,a few efforts are made to address the issue mentioned above.First,a collection of Davallioid used in Yunnan was compiled through the herbalogical study,geographic distributions,sales medicinal meterials,ethnic and folk application.Second,a systematic study of identification of Davallioid was conducted,employing analyses of morphology,DNA barcoding,and mineral elements.The conclusions drawn are shown below:1.The Davallioid surveyed cover three families(Drynariaceae,Davalliaceae,and Polypodiaceae),in which there are 13 generas,and 27 species totally.Drynaria sinica and Davallia formosana are used as the local conventional medicines.Drynaria propinqua,Drynaria delavayi,Microsorum membranaceum,Pseudodrynaria coronans,Humata tyermanni,Phymatosorus cuspidatus and Phymatopteris crenatopinnata are the mainly confusing medicinal materials of rhizoma drynariae.The other species of Davallioid can be found application in local herb streets,bazaars,produce markets,or can be inquired from local herb farmers and TCM practitioners.2.The mainly identifications for Davallioid and medicinal materials are the color,shapes,and arrangement of vascular bundle in rhizome section.The second identifications are the vascular bundle of petiole,surface decoration of spore surface,the edge of scales,the shape of the medicinal materials and the color of rhizome section.In the between families of Davallioid there are salient features in the sizes of scales,the types of sieve pore,leaf shapes,leaf epidermis cells,sorus,the sizes of rhizome.In the between generas of Davallioid there are identifications in the shape and tip scale,sporangia.However,no useful features are found in the phyllotaxy,leaf texture,morphology of leaf epidermis,root surface colors,and rhizomatous odors and rhizomatous textures.3.trnL-F,matK,ITS2 and rps4 sequences showed had poor reservation and were not suitable for the DNA barcoding identification of the Davallioid.According to the species identification of Davallioid results,rps4-trnS is the best seqquence for the DNA barcoding identification of the Davallioid,atpB-rbc L as a complement sequences.Combined sequences were found to be of the highest identification in the atpB+rbcL+psbA-trnH,atpB+rbcL+rps4-trnS,and atpB+rbc L+psbA-trnH+rps4-trnS.In considerations of DNA barcoding requirements(fast and efficient),we suggest that the combined sequences with two sequences be used in the assays of identifying Davallioid,namely,atpB+rps4-trnS.4.In the assays,calcium(Ca)were always the element with highest content.Other highly occurring elements were kalium(K),magnesium(Mg),phosphorus(P),iron(Fe),manganese(Mn).Those rich elements were not found to exist in a specific species or families or genera of plants.Instead,they were scattered in different families and genera of plants.It is believed that mineral elements may play a role in the curing power of Davallioid.But this assumption needs further investigations.There were evidences that the abundance of mineral elements in Davallioid was associated with the origins,process and cultivation of plants.In summary,we have identified the species that were found in the Davallioid used in Yunnan Area.It provides a reference for the quality control,the rational exploitation and utilization of Davallioid resources.We also systematically analyzed the morphological features of Davallioid and screened out DNA barcoding that could be used for the identification of Davallioid plants as molecular biological evidences.Finally,we found that there was some similarity in the component of rich elements in the Davallioid,which was a valuable reference to the future development and discovery of the TCM of orthopedics and traumatology.