Study On Genetic Diversity Of Germplasm Resources Of Chrysanthemum Morifolium On The Main Producing Areas

Chrysanthemum (Chrysanthemum morifolium Ramat.) is the dry flower heads from the Compositae chrysanthemum.Modern pharmacological studies confirmed that Chrysanthemum morifolium has antioxidant, anticancer, anti-inflammation,vasodilator and so on, and the application are widely in medicine, health, beauty and herbs. Due to its problems of rich variety diversity, a wide range of inherent chemical components, complex genetic relationships, they indirectly limit the genetic improvement process and production practice of the germplasm resources of Chrysanthemum morifolium.And the current market more need some kinds of chemical components such as high polysaccharide, flavonoids and other high yield and high efficiency of Chrysanthemum morifolium new varieties. In order to evaluate the genetic diversity of the germplasm resources and to provide a scientific basis for the selection of high quality and high yield varieties, the main results of this paper are as follows:1.Study on the morphological diversity of germplasm resources of Chrysanthemum morifolium. Through the observation of 13 morphological characters in the 20 germplasm resources of Chrysanthemum morifolium, the differences of different varieties were found. Among them, morphological differences of the five traits of petiole length, leaf blade serrate number, ligulate flower color, ligulate flower number and flower layers was most obvious.In the morphological correlation analysis,we found that flowers layers and petiole length, flowers layers and leaf blade serrate number, flowers layers and ligulate flower number had a significant correlation. It would provide basis for the genetic diversity research of Chrysanthemum morifolium and breeding new varieties.2. Study on the chemical compositions diversity of germplasm resources of Chrysanthemum morifolium. To systematically analyzed the content of eight kinds of effective chemical composition in 21 germplasm resources and to establish the HPLC fingerprint of different germplasm resources, we found different type of the chemical composition of Chrysanthemum morifolium basically were the same, but the effective components had obvious differences. Among them, the difference of chemical composition content of total flavonoids, chlorogenic acid, luteolin,3,5-O-second coffee acyl-quinic acid and volatile oil were obvious. In the chemical compositions’ correlation analysis,we found that there were some correlations in the compositions,such as total flavonoids and chlorogenic acid, total flavonoids and luteolin and so on. It was worth mentioning that the contents of effective components of Macheng-local,Xiaoyang,Jinju,Wangong were generally higher in the germplasm resources of Chrysanthemum morifolium.3. Study on the DNA barcoding of germplasm resources of Chrysanthemum morifolium. To use the ITS2 and matK sequence of DNA barcoding, we had the PCR amplification of the genomic DNA in 20 germplasm resources of Chrysanthemum morifolium.The results for the bands of ITS2 sequence were at around 500 bp; the bands of matK sequence were between 750 bp and 1000 bp. Comparison analysis of two sequence showed that the amplification of ITS2 and matK sequence in the different germplasm resources had a small difference, but the bases of ITS2 sequence were relatively greater than the matK sequence in the amplification. It was showed that ITS2 sequence was more favorable in the genetic diversity of Chrysanthemum morifolium.4. Study on the ISSR Molecular marker of germplasm resources of Chrysanthemum morifolium.To use the ISSR Molecular marker technique, we had the PCR amplification of the genomic DNA in the germplasm resources of Chrysanthemum morifolium and had the optimization of ISSR-PCR reaction system.Then we got the best system for the total volume of 50 uL, Taq enzyme 2.5 U, primer 0.4 μmol/L, dNTP 0.2 mmol/L, Mg2+ 1.0 mmol/L, DNA template 50 ng.And the optimal annealing temperature were optimized on every reaction. From 80 ISSR primers,we screened 21 ISSR primers in the genomic DNA of Chrysanthemum morifolium. A total of 256 bands were amplified from the genomic DNA of Chrysanthemum morifolium. The numbers of polymorphic bands were 248, and the polymorphism rate ranged from 83.3%-100%. It was showed that ISSR primers had good polymorphism that could be used for the genetic diversity of Chrysanthemum morifolium.5.General analysis on the genetic diversity of Chrysanthemum morifolium. Through the morphology, chemical compositions, DNA barcoding and ISSR molecular markers of the germplasm resources analyzed,we had some results. Clustering results from different research methods were in different extent reflects regional characteristics of Chrysanthemum morifolium’samples. A comparative analysis of the different chemical components and their morphology showed that the correlation between them was small. But many samples with generally higher effective components had the features of less number of chrysanthemum leaves jagged and a large number of ray florets.At the same time, we found some specific bands which might be related to the morphology and chemical composition of Chrysanthemum morifolium and found some specific bands of higher content of the chemical composition of Chrysanthemum morifolium.