Study On Morphology And Cytology Of Aquilaria Sinensis (Lour.) Gilg

Aquilaria sinensis(Lour.) Gilg,also named Chinese Eaglewood,belongs to Thymelaeaceae.It is an evergreen tree,from which the resiniferous lignum is the Chinese medicine Lignum Aquilariae Resinatum rated in Pharmacopeia of the People's Republic of China.Lignum Aquilariae Resinatum is a kind of precious Chinese medicine used for qi-regulating medicinal.In The Grand Materia Medica,the medicine is recorded as "pungent with a little warm engegy,and has the actions of Iowering Qi, grasping Kidney Qi,coursing the Liver etc."A.sinensis is a medicine source endemic to China and the only species which can produce Chinese Medicine Lignum Aquilariae Resinatum.In recent years,the wild Aquilaria sinensis has been severely damaged,thus large scale plantation has become the primary way to protect the germplasm resource as well as to meet medicine needs. Nowadays in the process of scale plantation,the seedlings are primary from the wild trees of Hainan and Guangdong Province.The seedling origin varies and does not have systematic screening,so the germplasm is uneven and the accretion is irregular,which have brought difficulties to the plantation management.Besides.A.sinensis seeds are recalcitrant seeds with the characteristics of low maturing rate,low germination rate, short survival cycle and weak self-renewal capacity of germplasm etc.Germplasm resource is the fundamental part for the industrial development.As a result,a systematic study on germplasm resource of A.sinensis plays an essential practical role in the protection and sustainable development of the A.sinensis sources,the development of the industrial plantation,as well as the guarantee of the medicinal quality.In coordination with The 10th Five Years Key Programs for Science and Technology Development of China:Study on rare and endangered medicinal A.sinensis germplasm resource and evaluation,the study tried to analyze the populations of different phenotypes of A.sinensis germplasm through morphology way,to make karyotype analysis and isozyme analysis at the cell level to different populations,and to evaluate the genetic diversity of A.sinensis so as to provide necessary theoretical support for the good quality germplasm screening,preservation and germplasm creation. 1.Literature review both at home and abroadAfter looking through a great deal of literature materials related to the study,the study state of the medicinal germplasm resource had been concluded,and the review on studies of A.sinensis germplasm resource had been made from the aspects of A.sinensis tissue structure,DNA level,chemical constituents and plant physiology,tissue cultivation and plantaion etc.According to the state of the A.sinensis germplasm,the conclusion that evaluation on the genetic diversity of the germplasm was necessary had been drawn.2.Morphology comparison on different germplasm resource of A.sinensisBy investigating the germplasm resource in Guangdong,Hainan etc,where samples of 7 natural populations had been collected,recorded the data of the leaf shape,leaf margin, petiole,stem surface,heartwood color,sepal,fruit shape and size etc.The statistics were analyzed by using SPSS 13.0 software,and the traditional classification was adopted to have a cluster analysis in accordance with the similarities and differences.Results:the A. sinensis germplasm was characterized by its rich diversity.The 7 groups could be divided into three categories:Macrophyll type,oval-leaved type and Xinglong population as one category;Trans-leaved type and Danzhou population as another; Microphyll type and Shenzhen population as the third.The constituents showed that three characters of wide leaf,long leaf and heavy 1000-seed weight contributed to the variation of A.sinensis phenotypes.3.Karyotype analysis on A.sinensis germplasm resourceAccording to the results of morphology study,selected experiment samples which were typical,distinct,and made kar-yotype analysis with the vigorous stem apex as experimental materials.Results:The somatic chromosome number was 2n=16, karyotype formula was K(2n)=2x=16==10m+4sm+2st,which belonged to "2A". Conclusion:The data of karyotype indicated A.sinensis chromosome was in the advanced stage of evolution.4.Isozyme analysis on different phenotypes of A.sinensis germplasm resourceTake A.sinensis groups of different phenotypes as experimental materials,adopted the vertical polyacrylamide gel electrophoresis to detect the enzymeatic system MDH,POD etc,analyzed the geneloci disparation of the detected enzymatic system,and investigated the genetic diversity and genetic differentiation among the samples.Results: five isoloci genes had been found in the peroxydase isoloci enzymatic system,among which 4 were polymorphic site,occupied 80%.The gene frequency in different sites among various A.sinensis groups was different,and POD-4 was the most predominance. The diversity index in A.sinensis was higher than dicotyledons both in species level and group level.It was also higher than mongrel,entomophila outcross and anemophily outcross from the breeding system angle.So A.sinensis had a higher genetic diversity level,which was probably related to many bionomics of the species itself.