Comparison Of Population Genetics Between Wild And Cultivated Paris Polyphylla Var.yunnanensis

Paris polyphylla Smith var.yunnanensis（Franch.）Hand.-Mazz.is one of the original species of Paridis Rhizoma,belonging to perennial herb of the genus Paris（Liliaceae）,which is used for detoxification,acesodyne,cool liver etc.Due to high demand for the medicine,wild individuals encounter in over collection for a long time,thus they become extremely rare in wild and has been listed as a national second-class endangered medicinal plant.In recent years,in order to relieve situation of resource shortage for Paridis Rhizoma,the artificial planting industry for P.polyphylla var.yunnanensis has risen.Because of complicated morphology between P.polyphylla var.yunnanensis and its relatives,identification of species or varieties was relatively difficult.Caused phenomenon of mix provenance in many cultivated bases,stability of quality of Paridis Rhizoma was seriously influenced,as well as healthy development of its planting industry.In this study,we collected 15 wild populations and 17 cultivated populations,to explore genetic diversity and genetic structure in wild and cultivated populations,compare genetic diversity between wild group and cultivate group,assess mixed provenances in cultivated bases,and preliminary reveal phylogeography and protecting strategies of wild P.polyphylla var.yunnanensis.The main conclusions can be summarized as follows:1.Genetic diversity and structure for wild and cultivated P.polyphylla var.yunnanensis based on AFLPFive AFLP primers of selective amplification were used for genetic diversity and structure on 15 wild and 17 cultivated populations of P.polyphylla var.yunnanensis（a total of 32populations）.In species and populations level,genetic diversity of all of populations,wild and cultivated populations was 0.2657、0.2616、0.2636;0.2002、0.2001、0.2002,respectively,which indicated that genetic diversity of the cultivated populations was slightly higher than the wild,so the cultivated did not result in obvious loss of genetic variations.Among wild populations,genetic diversity of wild populations from Guizhou was relatively high while genetic diversity of wild populations from Yunnan was obviously low;On the contrary,genetic diversity of cultivated populations located in Guizhou was lower than from Yunnan.Although wild and cultivated populations were divided into three subgroups on the basis of UPGMA dendrogram,which was in accordance with analysis of the PCo A and STRUCTURE.Moreover,in mantel test analysis,wild populations were a significant correlation between geographic distance and genetic distance（r=0.6767,P=0.001）,while cultivated populations were not a significant correlation（r=0.0392,P=0.3530）,indicating that there might a relatively confused mutual introduction of provenances.According to AMOVA analysis,there was no obviously genetic differentiation between the wild and cultivated populations that only 1.35%of genetic variations existed between the two groups,showing P.polyphylla var.yunnanensis has not experienced long selection and breeding.2.Analysis of population genetics for P.polyphylla var.yunnanensis based on a cp DNA region（trn L-trn F）There were 15 cp DNA haplotypes identified in 32 populations,orginating from trn L-trn F sequence data.Among them,wild and cultivated populations had 10 and 14 haplotypes,respectively.In species level,genetic diversity of wild and cultivated populations was 0.861,0.900,respectively,so genetic diversity of the wild was slightly lower than the cultivated,which was in agreement with conclusion of AFLP marker.According to mantel test analysis,wild group existed a significant correlation between geographic distance and genetic distance（r=0.3178,P=0.02）,meanwhile,comparative results of genetic differentiation coefficient G_ST and N_ST supported this conclusion.However,cultivated group was not a significant correlation（r=0.1629,P>0.05）.Similarity,comparative results of genetic differentiation coefficient also supported cultivated conclusion.Final conclusions based on trn L-trn F was in accord with AFLP marker for genetic diversity and structure of wild and cultivated populations.In AMOVA analysis,there was no obviously genetic differentiation between the wild and cultivated populations that only 2.5%of genetic variations existed between the two groups.3.Phylogeography for wild P.polyphylla var.yunnanensiscp DNA trn L-trn F region was used for phylogeography analysis of wild P.polyphylla var.yunnanensis.According to neutrality tests and mismatch distribution,the results showed no population expansion in recent history.The wild species was divided into 2 clades based on map of evolutionary relationship and geographical distribution.Among them,haplotypes of first clade were mainly distributed in Guizhou,and H1 was located in center;haplotypes of second clade were distributed in Yunnan and HD,and H6 was located in center.Because of H1widely distributed in Guizhou and H6 widely distributed in western Yunnan,we speculated that these two field were refugia of P.polyphylla var.yunnanensis in Quaternary glaciation.By map of evolutionary relationship and geographical distribution,there was a close relationship between H9 located in CN and haplotypes from Guizhou,which indicated that wild population from CN might be formed through the equidistant transmission of birds or escaping from cultivated bases.4.Protecting strategies and sustainable utilization of germplasm resource of P.polyphylla var.yunnanensisIn field work,we found that distribution of P.polyphylla var.yunnanensis was relatively wide,but some area only corrected few wild individuals,for example LL and XY from Guizhou;YM and CN located in Yunnan,so wild resources of P.polyphylla var.yunnanensis might be very endangered.As a national second-class endangered medicinal plant,valid protecting strategies for P.polyphylla var.yunnanensis were formulated which was profound meaning for utilization and sustainable development.In this study,AFLP marker and cp DNA region were used to detect genetic diversity of 15 wild populations from three provinces.The results indicated that genetic diversity of wild populations distributed in Guizhou was relatively high.Meanwhile,genetic diversity of wild populations from Sichuan was also high,but due to only one population（HD）,the real situation needed to be further assessed.Meanwhile,based on phylogeography for wild P.polyphylla var.yunnanensis,the results showed that Guizhou province and western Yunnan might be two independent refugia in glaciation,so suggesting that wild individuals distributed in Guizhou should be given priority protection.On the one hand,in-situ conservation was adopted in wild distribution,strict prohibiting to collect for P.polyphylla var.yunnanensis and effective protecting nature environment;On the other hand,wild germplasm nurseries were established for systematic ex-situ conservation.In addition,methods of artificial intervention should also be developed to promote restoration and growth of wild population,such as plant regression method,removing wild seed coat and so on.On the basis of genetic structure for 17 cultivated populations,provenances of cultivating lands might exist mix phenomenon,which would confuse instability of quality of medicinal materials,further influencing healthy development of industry of Paridis Rhizome.Thus,cultivated bases should do a good job in the selection and purification of provenances,then cultivating high-quality provenances of P.polyphylla var.yunnanensis and promoting,so as to provide high-quality raw materials for developing of industry of Paridis Rhizome.