Accurate Evaluation Of Germplasm Resources And Selection Of Excellent Germplasm Resources Of Blumea Balsamifera (L.) DC.

Blumea balsamifera（L.）DC.is a perennial herb of the compositae family,with the efficacy of warming the middle and promoting blood circulation.In this study,the evaluation technical specification was established by observing the descriptive traits of B.balsamifera,and then the germplasm resources of B.balsamifera were preliminarily evaluated and identified to screen out excellent individual plants.The tissue culture technology was used to expand the excellent individual plants.Finally,through the cultivation and comparison of five germplasms in three regions,the differences in quantitative traits between different genotypes and the same germplasm in different habitats were discussed,aiming to improve the quality of B.balsamifera products and provide quality guarantee conditions for the development of B.balsamifera market..The main results of this study are as follows:1.Specifications for description and evaluation of germplasm resources of B.balsamifera were developed.Referring to the published character description specifications and data standards of other crops,the descriptive characters of 55 germplasm resources of B.balsamifera were observed.Combined with the characteristics and related research progress of B.balsamifera germplasm resources,the terms and definitions,technical requirements,identification methods and evaluation and determination of excellent germplasm resources of B.balsamifera germplasm resources were stipulated.The《Specification for description and evaluation of B.balsamifera germplasm resources》was compiled to provide technical basis for the investigation,collection,cataloguing,sorting and preservation of B.balsamifera germplasm resources.2.40 germplasm materials were preliminarily screened for accurate evaluation.The variation coefficient of L-borneol content in quantitative traits was the highest,which was54.61%,indicating that there were great differences in L-borneol content among different germplasms.Among the quality traits,the variation types of leaf shape were the most abundant and the Shannon-wiener index was the highest（1.201）,indicating that leaf shape had abundant genetic diversity.Cluster analysis divided 159 accessions into 5 groups.Eight principal components were extracted by principal component analysis,which were classified into seven factors:yield factor,color factor,borneol factor,leaf shape factor,leaf margin factor,leaf green factor and flower branch angle factor.Based on the results of principal component analysis,the comprehensive evaluation of various qualities was carried out.According to the evaluation score ranking,the top 40 germplasm materials were selected for the accurate evaluation of the germplasm resources of B.balsamifera.3.Establishment of tissue culture and propagation system of B.balsamifera.The young stems of B.balsamifera were used as explants.The explants were soaked in 75%ethanol for90 s+2 g/L Hg Cl₂for 10 min.The induction effect was the best when 1.5 mg/L 6-BA+0.05mg/L NAA was added to the induction medium,and the induction rate reached 28.54%.When 6-BA 2.0 mg/L+NAA 0.05 mg/L was added in the proliferation medium,the proliferation effect of cluster buds was the best,and the proliferation coefficient reached 3.91.The medium of 1/2MS+NAA 0.1 mg/L should be selected to promote rooting.In addition,in this study,adventitious bud differentiation was induced by the root segment of aseptic seedlings,which could accelerate the efficiency of secondary propagation.The optimal medium composition was MS+sucrose 30 g/L+6-BA 1.0 mg/L+NAA 0.05 mg/L.4.Different germplasms and environments have great effects on the quantitative traits of B.balsamifera..The genetic diversity of quantitative traits of different germplasms in different regions is rich,and the degree of variation and differentiation is large.Among them,the quantitative traits of F2-8 are excellent,with stable genetic characteristics and strong resistance.The genetic characteristics of phenotypic traits in Danzhou region were the most stable.The number of first-order branches,main stem diameter,leaf length and petiole length varied abundantly in Luodian region,while the plant height,plant width,leaf width and leaf thickness varied greatly in Zhanjiang region.There were linear relationships between 11 quantitative traits and latitude,average annual temperature,maximum temperature,sunshine hours,available potassium and pH value,and the regression coefficient reached extremely significant level（p<0.01）.Among them,longitude had the greatest effect on quantitative traits,followed by pH value.