Seedling Growth Characteristics Of Ex-situ Taxus Cuspidata By Sources

In this study,fifteen growth characteristics including the preservation rate,aboveground and underground traits of Taxus cuspidata seedlings from Kuandian,Benxi,Helong,Wangqing and Muling were determined by field experiments.Four-year-old seedlings were observed at three experimental sites in Shandong,Beijing and Liaoning.Based on the correlation between phenotypic traits and ecological factors of origin,the geographic variation of Taxus cuspidata was revealed.Five sources were classified into three categories by cluster analysis.The main results are as follows:1.In Shandong and Liaoning experimental sites,seedlings from Wangqing source showed the best performance,while those from Kuandian source showed the worst performance.However,wangqing source performed best and Helong source performed worst in Beijing test site.In a word,Taxus cuspidata has the worst adaptation performance in Beijing and the best adaptation performance in Shandong.2.The results of multi-site joint combined variance analysis showed that the net growth of seedling height,ground diameter,crown width,longest lateral branch length,current shooting length,total root length,root surface area,aboveground dry weight,underground dry weight and total dry weight showed significant differences(P<0.01)between sources and locations,as well as the interactions between sources and locations.The net growth of the number of lateral branches and the volume of roots showed significant difference between sources and locations.Mean root diameter and specific root length showed significant differences between locations,which all indicated that each trait was strongly influenced by the environment.The variance components of seedling height,ground diameter,crown width,current shoot length,longest lateral branch length and total root length,root surface area,root volume,aboveground dry weight,underground dry weight and total dry weight between locations were highest than others.The results showed that the location effect had the greatest influence on the growth of Taxus cuspidata.3.The seedling height,shooting length,aboveground dry weight,underground dry weight,total dry weight,total root length,root surface area and root volume of Taxus cuspidata were significantly or very significantly positively correlated with longitude and latitude of the original place,indicating that the Taxus cuspidata had obvious longitude and latitude geographic variation.With the increase of latitude and longitude,the seedling height,shooting length,aboveground dry weight,underground dry weight,total dry weight,total root length,root surface area and root volume grow better.The Taxus cuspidata source from less rainfall grow well in Shandong,Beijing and Liaoning experimental sites,and its roots are relatively developed.4.The Muling source which grow well and stably are suitable for large-scale ex situ conservation in 3 pilot sites.The Wangqing source which grow well but not stably are suitable for ex-situ protection in the suitable areas of Yantai in Shandong Province and Benxi in Liaoning Province.The Kuandian source have the worst performance in three pilot sites and the preservation rate is lowest than other sources,which is not suitable for ex-situ conservation.5.Principal Component Analysis showed that the Wangqing source performance the best in three test sites,while the Kuandian source performance the worst.The results of cluster analysis showed that Taxus cuspidata from five sources were divided into three groups,Wangqing and Muling were in one group,Kuandian was in two groups,and Helong and Benxi were in three groups.