A Preliminary Study On Genetic And Morphological Diversity Of Ancient Camphor-trees In Jiangxi Province

In this study, the genetic diversity and genetic structure of ancient camphor-trees in Anyi, Anfu, Ruijin, Wuyuan and Yanshan of Jiangxi province based on ISSR molecular marker were analyzed. And the diversity of branches and leaves’shape of ancient camphor-trees is studied with numerical taxonomic methods. The results are as follows:1. By adding 0.3g dry leaves of ancient camphor-trees in the 4mL CTAB extracting solution with 5% PVP and 2% (3-mercaptoethoxy ethanol, the high quality DNA of ancient camphor-trees gene group is obtained with the improved CTAB method.2. The reaction factor is designed as a single factor in the ISSR system, and the best ISSR-PCR reaction system of ancient camphor-trees is established as follows:50ng DNA template,2.5mmol·L-1 MgCl2,0.20mmol·L-1 dNTPS,1 U Taq polymerase,0.5 umol·L-1 primer in 20μL reaction volume and 2% formamide deionized. The reaction augmentation procedures are as follows:initial denaturation at 94℃ for 5 mins; followed by denatured at 94℃for another 45s, annealing at 48～58℃ for 90s (annealing temperature accoding to primers), extension at 72℃ for 90 s, cycling for 38 times; extension at 72℃for 7 mins.3. ISSR marker analysis results are as follows:the PPB of ancient camphor-trees is up to 94.51% at the species level. The gene diversity index of Nei’s is 0.3046, and the Shannon information index is 0.5057. The average P value of PPB is 78.68% at the population level, the average h value is 0.311 and the average I value is 0.456. The three genetic polarization indexes indicate that the genetic diversity is high.4. The clustering maps of five ancient camphor-tress populations are obtained with the UPGMA clustering method. There is no significant relationship of ancient camphor-trees between the genetic distance and the geographic distance (r=0.307, p=0.168, pvalue>0.05). The five ancient camphor-tress populations are divided into three categories: the two populations in Anyi and Wuyuan are clustered preferentially, then the two groups in Anfu and Ruijin are clustered preferentially, then the two groups in Anfu and Ruijin are clustered preferentially, finally, the four groups are clustered with the groups in Yanshan.5. Ten characters of 151 ancient camphor-trees leaves samples are analyzed with the numerical taxonomic methods, and they are also studied by using the Q cluster analysis, R cluster analysis and principal components analysis method. The result indicates that the ancient camphor-trees can not be divided into different groups based on the present sample and condition because the leaves’ shape of ancient camphor-trees is of high similarity. However, the shapes of ancient camphor-trees show two types:the edge of leaves is waved or non-waved. This character has a strong regularity in the ancient camphor-trees leaves. It provides a favorable basis for the future study of system classification and evolution manner of the plants in Lauraceae.