Genetic Diversity Of Liquidambar Formosana Hance Based On Morphology And ISSR Markers

Liquidambar formosana Hance is a plant of the genus Liquidambar,which is widely distributed in the south of The Qinling Mountains in China,and ha s important value in ornamental,medicinal,economic and ecological aspects.In recent years,there have been many reports on the ecological characteristics,s eed biological characteristics,leaf color change analysis and seedling and affore station techniques of Liquidambar formosana Hance.There are few reports on the morphological and molecular genetic diversity of Liquidambar formosana H ance.In this study,morphological markers and ISSR molecular markers were u sed to study the genetic diversity of 70 germplasm samples from 8 populations in Fujian,Hunan,Jiangxi and Anhui provinces.The effects of natural and arti ficial conditions on the genetic diversity of Liquidambar formosana Hance ger mplasm were analyzed,and the ISSR fingerprint was initially constructed.To p rovide theoretical knowledge background for rational management of Germplas m resources of Liquidambar formosana Hance and selective breeding.The mai n results of this study are as follows:1.Morphological statistics showed that among the seven phenotypic traits of Liquidambar formosana Hance,the highest coefficient of variation and diver sity index was leaf fresh weight,and the lowest was leaf length,indicating tha t the genetic diversity of leaf fresh weight was the highest,while that of leaf length was the lowest.The highest diversity index was found in Datian,and th e lowest was found in GZ,indicating that the phenotypic genetic diversity of Liquidambar formosana Hance in Datian was the highest and that of Liquidam bar formosana Hance was the lowest.The phenotypic genetic diversity of Liqu idambar formosana Hance in Changkou village was higher than that in the nat ural area.Principal component analysis showed that the first principal compone nt included leaf length,leaf width,leaf dry weight,leaf fresh weight,petiole t hickness and leaf thickness,and the maximum contribution value was leaf widt h.The results of correlation analysis showed that there was no significant corr elation between petiole length and leaf length,leaf width,leaf dry weight,leaf fresh weight,leaf thickness and petiole diameter,but there was significant corr elation between leaf length,leaf width,leaf dry weight,leaf fresh weight,leaf thickness and petiole diameter.2.Based on the morphological clustering analysis of 70 Liquidambar form osana Hance germplasm,the results showed that 70 Liquidambar formosana H ance germplasm could be divided into three groups when Euclidean distance w as 10.The first group mainly included 53 germplasm,among which the germp lasm from Hefei of Anhui province,Datian of Fujian Province,Guangze of Fu jian Province,Nanchang of Jiangxi Province and Nanjing of Fujian Province a ccounted for 75.71%of the total.They had thick and long petioles and heavy leaf trunks.The second largest group consisted of 15 germplasm,most of whic h came from natural and artificial areas of changkou Village,and a small part came from Datian and Nanjing of Fujian province,accounting for 21.42%of t he total.They had the characteristics of short and narrow leaves,thin and shor t petioles,and small fresh leaf weight.The third group included 2 germplasm,which all came from Yuelu Mountain,Hunan province,accounting for 2.85%o f the total,and all showed the characteristics of long and wide leaves.3.By single factor test and orthogonal test,the best ISSR-PCR reaction s ystem was obtained,which was 10μL:DNA polymerase 5U,template DNA 60 ng,primer concentration 0.8μmol/L,adding ddH20 to 10μL;The PCR amplifi cation procedure was pre-denaturation at 96℃ for 2min,denaturation at 96℃ f or 10s,optimal Tm30s,extension 90s at 72℃,38 cycles,and extension for 10 min at 72℃.4.The results showed that Nei’s gene diversity(H)of the species was 0.3451,and Nei’s gene diversity(H)of the 8 populations was 0.2763,indicating a high genetic diversity at the species level.The total genetic diversity(Ht),in tra-population genetic diversity(Hs),gene differentiation coefficient(Gst)and g ene flow Nm of the 8 populations were 0.3451,0.2763,0.1994,2.0079,19.94%and 80.06%respectively.The results indicated that the genetic variation of Li quidambar sweetgum was mainly in the population.At the same time,the gene flow Nm was 2.0079,greater than 1,indicating that the gene flow of Liquida mbar Liquidambar formosana Hance was at a high level,which was conducive to gene exchange among different populations.IS SR clustering analysis was c arried out on 8 populations of Liquidambar formosana Hance.The results sho wed that the 8 populations could be divided into two groups:the first group was artificial population in Jianchuangkou village,natural population in Jianchu angkou village and field population in Fujian province;The second subgroup w as divided into two subgroups.The first subgroup was from Hefei,Anhui prov ince,Yuelu Mountain,Hunan Province,Guangze,Fujian Province and Nanchan g,Jiangxi Province.The second subgroup was from Nanjing,Fujian Province.5.Three primers with high polymorphism and good repeatability were sele cted from the 10 primers to amplify 70 germplasm of Liquidambar formosana Hance,and the fingerprint of 70 germplasm could be established by the result statistics.The results show that:ISSR primer UBC830 could identify 48 Liquid ambar formosana Hance germplasm,ISSR primer UBC836 could identify 44 s Liquidambar formosana Hance germplasm,AND ISSR primer UBC890 could i dentify 50 Liquidambar formosana Hance germplasm.The ISSR fingerprint co mbined with primers UBC830,UBC836 and UBC890 was able to identify all Liquidambar formosana Hance germplasm.