| The Chionanthus retusus(Chionanthus retusus lindl.et Paxt.)is a family of Oleaceae plants of the genus Chionanthus retusus,deciduous shrubs or trees,also known as April snow,radish shredded flowers.The root system of tassel tree is developed,and the adaptability is strong.The trees are tall and beautiful,and the flowering period is from early April to the end of may every year.Its root,leaf,bark all can be used as medicine,it is to get commonly approbated officinal economy crop.In recent years,the distribution area and natural population area of tassel trees have been gradually reduced,and the wild germplasm resources are threatened by many aspects and tend to be endangered.At present,the research on Chionanthus retusus mainly focuses on breeding technology,chemical composition and medicinal value,and there is no related report on the distribution of tassel germplasm resources in provinces and cities of China and the genetic diversity at the molecular level,which greatly affects the utilization and protection of Chionanthus retusus germplasm resources.This research through to the nationwide provincial distribution of Chionanthus retusus and ancient trees fringed related germplasm resources distribution,quantity,growth condition of comprehensive survey,Chionanthus retusus germplasm resources in different regions of master,on the basis of the screening of the seven different provinces Chionanthus retusus population of 62 germplasm samples as the research object,)accessions was analyzed using SRAP molecular markers tassel population genetic diversity,genetic structure analysis,and use the genetic distance for different Chionanthus retusus populations were related cluster analysis,this paper in different areas of population genetic variation of Chionanthus retusus and distribution pattern,in order to Chionanthus retusus germplasm resources evaluation which provides the theoretical foundation,utilization and protection.The research results are as follows:(1)Chionanthus retusus 784 plants and ancient trees found in Shandong province includes 101 strains and 7 community per 683 plants,concentrated distribution in shandong,shandong peninsula and southeast coastal area of 11,74 strains have specific growth index,one of the biggest tree height of 17.0 m,the smallest is 6.0 m,the average height under branch height of 2.76 m,average diameter at breast height is 63.41 cm,female strains(52.7%).Ancient community are mainly distributed in shandong and south-east areas,between longitude E116°50'~ E119°00',latitude N35 °00 '~ N37 °00' between Zibo has four communities.There were 124 first-order fringed ancient trees(including community),accounting for 15.81 %.30 secondary ancient trees,3.83 %;630 tertiary ancient trees accounted for 80.36 %.In the healthy condition,the tassel ancient trees accounted for 74.32%,14.86%,6.76%and 4.06% respectively.(2)Ancient Chionanthus retusus trees in Shandong,Hebei,Henan,Tianjin,Beijing,Shanxi,Shanxi,Jiangsu,Sichuan,Yunnan,Fujian,Anhui,Hubei,and Liaoning province are found a total of 14 provincial level administrative regions,have been found in other areas as tassels more ancient trees grown up in some remote mountainous area,the lack of professional maintenance,much depends on the active maintenance of consciousness,the majority is in a state of death,including two strains Chionanthus retusus death caused by man-made factors and ancient trees,a small number of growth in the Chionanthus retusus interference is less ancient trees in the mountain.(3)Eight pairs of primers with clear polymorphism were selected from 64 pairs of primers for SRAP amplification,and a total of 1728 primers were generated,of which 1649 were polymorphic,and the percentage of polymorphic primers was 95.43%.Based on the analysis of genetic diversity of tasso,the mean number of effective alleles(Ne),Nei's gene diversity index(H)and the average number of effective alleles(Ne)in 62 Chionanthus retusus germplasms was 1.2137,0.1537 and 0.2680 respectively.The Ne(1.2374)of the primer combination me2-em7 was the largest.H(0.1685)and I(0.2987)of the primer combination me-em6 were the largest.The Ne(1.1626),H(0.1227)and I(0.2244)of me6-em1 were the smallest.102 specific bands were generated by the amplification of 62 tassel germplasm materials,accounting for 6.19% of the total number of polymorphic bands.(4)The genetic similarity coefficient of 62 Chionanthus retusus germplasm ranged from0.7164 to 0.8426,with an average value of 0.7735.The number of effective alleles(Ne)among the seven Chionanthus retusus populations was between 1.1950 and 1.2265,the gene diversity index(H)of Ne was between 0.1315 and 0.1504,and the Shannon polymorphism information index(I)was between 1.1950 and 1.2265.The genetic consistency(In)was between 0.8980 and 0.9736,and the average geneticconsistency was 0.9344.The genetic distance(GD)was between 0.0267 and 0.1108,and the average genetic distance was 0.0682.(5)Using UPGMA method to construct the genetic relationship between clustering figure,7 Chionanthus retusus population can be divided into five categories,for ? Adventist development Tongbai county in Henan province and Shanxi Province city class,anlu Qingzhou of Shandong province and Hubei province are respectively independent ?,?,Jiangsu Shuyang and Huairou as ?,Baoding city,Hebei province is the first ? class.(6)The gene diversity index(Gst)among the populations was 0.1336.Through the analysis and comparison of genetic consistency and genetic distance,it was found that there was a certain degree of gene communication between different populations,and genetic variation mainly existed in the population.Based on the investigation and collection of the national tassel germplasm resources and the above experimental results,the conservation strategies of ancient Chionanthus retusus were proposed. |
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