Research On Phenotypic Diversity Of Chinese Wild Herbaceous Peonies And Utilization Potential Of Their Seeds And Roots

China is one of the distribution centers of Paeonia.Paeonia lactiflora is the only wild species used for medical and ornamental purposes,while few studies on the other species have been performed.In this study,the germplasm resources of 8 species and 1 subspecies of wild herbaceous peonies were investigated,including P.lactiflora,P.veitchii,P.anomala,P.intermedia,P.mairei,P.streniana,P.emodi P.obovata subsp.obovata and P.obovata subsp.willmottiae,for two years.The the phenotypic diversity of pollen and seeds for 8 species and 1 subspecies were analyzed along with phenotypic diversity of P.veitchii populations was analyzed.These studies revealed the phenotypic diversity of Chinese wild herbaceous peonies.Based on the investigation of resources,the seed fatty acidsn composition,seed secondary metabolites and root secondary metabolites of Chinese wild herbaceous peonies were analyzed and evaluated to reveal their potential utilization value.The main results are as follows:1.Through field investigation,it was found that wild herbaceous peonies are mainly distributed in Central China,Southwest China and Northwest China,followed by Northeast China,Xinjiang and Tibet.The morphology and habitat of various wild species differ to a greater extent.The weak spontaneous reproduction capacity and serious human destruction may be the main factors leading to the endangered wild herbaceous peonies.Pollen and seeds are relatively easy to preserve as they possess abundant genetic diversity information.The pollen of 21 populations and mature seeds of 22 populations of 8 species and1 subspecies peonies were systematically collected and their phenotypic data were statistically analyzed.It was found that the pollen of Chinese wild herbaceous peonies were mostly super long spherical,long globular,some were nearly spherical,and the polar view was trifid round.There were differences in pollen morphology among different populations,but the differentiation was not intense.The mature seeds of Chinese wild herbaceous peonies mainly have three colors: blue black,black and brown;there are two kinds of seed cortex: hard stone and flesh;the seed coat is smooth or rough,and the shape of seeds is regular oval or irregular oval.The seed size and quality of Chinese wild herbaceous peonies are different;the seed size and quality of P.intermedia are the smallest among them,whereas the 100 seed weight of it is less than 4 g.The seed size and quality are inversely proportional to the latitude of origin.This may be a change made by wild herbaceous peonies to adapt to the environment.P.veitchii is an endemic peony species in China,which had a wide range of distribution and rich phenotypic diversity.A total of 15 phenotypic traits of 6 representative populations of P.veitchii were analysised.The results showed that the average Shannon Weaver indexes of different populations and different traits of P.veitchii were 1.4510 and 1.6475,respectively,with high diversity,while the diversity among populations was greater than that within populations.These results provide a theoretical basis for the protection,development and utilization of P.veitchii.2.Seed kernel fatty acid composition of 16 populations of 8 species and 1 subspecies Chinese wild herbaceous peonies were determined by gas chromatography tandem mass spectrometry(GC-MS).The results showed that the main fatty acids in the seed kernel were oleic acid,linoleic acid,?-linolenic acid,stearic acid and palmitic acid.The relative content of ?-linolenic acid and unsaturated fatty acid are more than 47.0% and 93.5% respectively.In general,Chinese wild herbaceous peonies have the potential to be used as oil crops.High-performance liquid chromatography diode array detection(HPLC-DAD)and high-performance liquid chromatography quadrupole time of flight mass spectrometry(HPLC-Q-TOFMS)were used to analyze the secondary metabolites in the seed testa and kernel of Chinese wild herbaceous peonies.A total of 33 secondary metabolites were identified and categorized into stilbenes,flavonoids,triterpenoids,phenols,tannins and monoterpenoid glycosides.The species and contents of secondary metabolites in seed testa and seed kernel were significantly different.The highest content of stilbene in seed testa and highest monoterpene glycosides in seed kernel were found.The standards were used to analyze the components of stilbene in seed testa and glucosides in seed kernel of wild herbaceous peonies.It was found that the content of resveratrol trimer in the seed testa samples was more than 77%,which was mainly suffruticosol B and Gnetin H.The proportion of paeoniflorin in seed kernel was high(33.60-81.84%),and P.lactiflora had the highest(58.49-81.84%).The results of in vitro antioxidant activity showed that the antioxidant activity of seed testa was significantly higher than that of seed kernel.By taking results into consideration,the human keratinocyte UV-B irradiation model was used to study the effects of extracts from P.lactiflora and P.anomala seed testa on anti-aging of human skin.It was inferred that the two kinds of peony seed testa extracts can effectively inhibit the production of MMP-1,thus reducing the degradation of collagen,which indicates that wild herbaceous peony seed testa extract has the potential to develop anti-aging products.3.The secondary metabolites of roots and seeds of 8 species and 1 subspecies of Chinese wild herbaceous peonies were analyzed by HPLC-DAD and HPLC-Q-TOF-MS.A total of 21 secondary metabolites were identified and inferred from 20 samples of roots,which belonged to monoterpenoid glycosides,phenols,paeonols,tannins and flavonoids.There were great differences in the types and contents of secondary metabolites among different root samples.In addition,the contents of monoterpene glycosides and tannins in root samples were generally higher than others.It was found that the content of paeoniflorin in the root of some populations of P.obovata subsp.willmottiae,P.mairei,P.sternaian and P.emodi reached the standard specified in the Pharmacopoeia(>18 mg/g DW),except for the P.lactiflora and P.veitchii.The content of lactiflorin and monoterpene glycosides in P.mairei was significantly higher than others,while the contents of paeoniflorin in P.obovata subsp.obovata and P.intermedia were significantly lower than others(<4 mg/g DW).