Germplasm Identification,Evaluation And Screening Of High Yield And High Active Component Content Of Astragalus Membranaceus Var.Mongholicus

Cultivation and breeding of medicinal plants has become a hotspot in international research on medicinal herbs under the demand of the current health industry.Astragalus membranaceus var.mongholicus is a local medicinal plant in Inner Mongolia with good pharmacological effects.At present,the research on high-quality new varieties is lagging behind,and there is no new variety suitable for planting in Inner Mongolia.Therefore,it is very important to carry out the breeding of new varieties of medicinal materials Astragalus membranaceus var.mongholicus to promote the healthy development of Inner Mongolia biomedical industry.In this study,from 2018 to 2023,through the evaluation of Astragalus membranaceus var.mongholicus germplasm resources,screening of excellent germplasm,selection of cultivated plant groups,identification of biological characteristics and herb quality,screening of secondary metabolite synthesis-related genes by transcriptome analysis,and evaluation of excellent germplasm.The aim is to screen new germplasms with high yield of medicinal materials and new germplasms with high content of two main active ingredients astragaloside IV and calycosin7-O-β-DGlucopyranoside.The main results are as follows.1.Root phenotypic characteristics of the four groups of herbs with choose to cultivate of the yield characteristics of the index from high to low as G(d ≥ 23mm)> Z(d = 20～23mm)> H(d = 16～20mm)> L(d ≤ 16mm),the yield change range of94.57～225.27 g,type G yield characteristics are the most prominent for 225.27g;astragaloside IV content of the special this indicator H>L=G>Z in order,are higher than the Pharmacopoeia(2020)standard 0.08%,the content change range is 0.09～0.11%,group H astragaloside IV content features the most prominent,0.11%;calycosin7-O-β-DGlucopyranoside content in order of G>Z>H=L,the change range is 0.04～0.07%,are higher than the Pharmacopoeia standard 0.02%,group G calycosin7-O-β-DGlucopyranoside content is the highest,0.07%.2.Observations were made for two consecutive years to verify the correlation between the root characterization of the biennial herbs and the growth characteristics of the aboveground plants.The aboveground agronomic characters of the four groups were number of branches(ranging from L 1.89 to G 2.69),number of lateral branches(Z 12.04 to G 18.48),length of terminal branch(H 20.76 to G 29.92 cm),length of internode(G12.00 to L 16.89 mm),length and width of compound leaf(H 80.85 to Z 97.36,G 22.57 to H 23.68mm),leaf weight(L 0.95～G 1.36g),leaflet length and width(H 13.44～L 15.43,Z 6.35～L 7.31mm),number of leaflets(L 25.23～G 27.91),root stoutness(L 13.56～G28.33mm),xylem/phloem ratio(L 1.08～G 1.23),and xylem coloration(H pale brown 3～G pale brown 4)variations were strongly correlated with the differences in yield,astragaloside IV and calycosin7-O-β-D-Glucopyranoside content exhibited by each type.3.Characteristic groups of G plants with early maturity,group H with late maturity,type L seeds with significantly higher thousand-seed weight than the other three groups(p<0.01),and a larger proportion of seeds with black seed coats,which can be identified directly with the naked eye by their organoleptic color after harvesting.4.Analyzing the DEGs of different root characterization types of Astragalus membranaceus var.mongholicus populations,1179 DEGs were identified in group Z＿vs＿L,519 and 660 genes were up-regulated and down-regulated,respectively.Group H＿vs＿Z detected 621 DEGs,and only 221 and 139 DEGs were detected in groups H＿vs＿L and H＿vs＿G.The effect of transcription between high yield group G and high astragaloside IV content group H was small;551 DEGs were detected in group G＿vs＿Z,only 203 DEGs were detected in group G＿vs＿L,and the effects of transcripts between the high-yield group G and the the differences in astragaloside IV content exhibited by the low yielding groups L had a small transcriptional effect,and the similarity between the high yielding group and the low yielding group at the transcriptional level made the two groups similar in terms of high astragaloside IV content.5.Root groups G,H and L had the highest number of shared Unigenes,lower number of DEGs and more similar germplasm affinities,while type Z had fewer shared genes and higher number of differentially expressed genes with the other types and most of the genes on the pathway related to synthesis of astragaloside IV and Calycosin7-O-β-D-Glucopyranoside such as ACAT,HMGCR,dxr,CAS,SE,IDI,PAL,4CL,CHS,HIOMT and some genes related to cellular macromolecule,nucleic acid and DNA metabolism,as well as carbohydrate metabolism,cell wall polysaccharide and hemicellulose metabolism,such as RPS4,ELF2 C,USP7,TOP2,SIAH1,PDPK1,TCH4,AGO,RDR gene and raffinose synthase,were significantly down-regulated,synthase were significantly downregulated,and the expression pattern of genes related to secondary metabolite accumulation in roots was significantly different from the other three types,which was the root cause of the differences in phenotype and active ingredient content between type Z and the other groups,and group Z was not suitable for further selection and breeding as a new variety.24 annotated structural DEGs related to the biosynthesis,transport,and catabolism of secondary metabolites in the roots of the four Astragalus membranaceus var.mongholicus root phenotypes differed from those of the other groups by regulating REF1,4CL,NCED,COMT,F5 H,F6H,FOLK,GGPS,HMGCR,GA2 ox,7-IOMT,dxr,IDI,SQLE,CAS1,CHS,CHI,HI4 OMT,peroxidase,and Cytochrome P450 expression to regulate phenotypes and secondary metabolite accumulation in different types.6.The genes of Yellow,Brown and Pink modules obtained from WGCNA analysis were highly specific among astragaloside IV content,Calycosin7-O-β-DGlucopyranoside content,herb yield traits and some aboveground agronomic traits in different groups of characterization groups,and the three modules screened out 12 candidate core genes associated with aboveground plant agronomic traits,root secondary metabolism content and yield CYCD1＿2＿4,pdx H,prc,UBXN7,SPOP,DBR,DODA,ABCB1-1,SERPINB,ABCB1-2,CDC20,SHP1.7.The overall coefficient of variation of two excellent new strains from the four characteristic populations were H and G,6.4 and 2.4,respectively,with strong seed consistency and specificity,high yield of seed materials and seedlings of original plants and new strains.Compared with the original material,the new lines H and G showed similar trends in seedling height,leaf length,leaf length,root length,root length and root thickness,which were both G> H.The growth and development in the seedling stage was fast,and the growth of the original plants stagnated in the later stage.Compared with L and Z,the growth of the same growth period was dominant.When the seeds of the two new strains were compared with the germplasm of different origins,the morphological differences of the seedling stage were significant,while the seedling stage variation coefficient of G seeds of the new strains was small(3.6).11 agronomic traits and seedling yield indexes were higher than those of other origins,and the seed consistency and specificity were strong.The root thickness and fresh weight of the new strain H were significantly higher than that of other germplasm,and had strong seed specificity.