Virus Elimination And Rejuvenation Of Tea Chrysanthemum Morifolium 'Qiyuebai' And 'Fubaiju'

Tea chrysanthemum(Chrysanthemum morifolium Ramat.)is perennial herbof Asteraceae.It is popular for its unique flavor and health benefits.The cultivation area of tea chrysanthemum in China has been expanding year after year.However,many asexual propagation methods such as cuttings and grafts,and continuous cropping of soil have caused serious virus diseases,resulting in the decline of flower quality,degenerative species and decline in production,which has reduced the economic benefits of the farmer and seriously restricted the development of the tea chrysanthemum industry.In this paper,two severely virus-infected tea chrysanthemums 'Qiyuebai' and 'Fubaiju' were identified,and the type of virus were determined,and detoxification of the virus was treated with4? low-temperature combination with ribavirin method.The genetic stability of the virus-free plants was analysed by SARP primers,and a system for the removal of the chrysanthemum virus was established,which laid a theoretical basis for the promotion of tea virus-free chrysanthemum seedlings and the development of the tea chrysanthemum industry.The main results are as follows:1.Thirty-nine kinds of tea chrysanthemum germplasm resources preserved in Chrysanthemum Germplasm Resource Conservation Center,Nanjing Agricultural University were used as the materials.The nested PCR method was used to investigate the infection type of the virus and viroids.Four dominant virus and viroids in the tea chrysanthemum were identified,which were CVB,TAV,CSVd and CChMVd.Among the 39 kinds of tea chrysanthemum,the highest infection rate was CSVd 100%,followed by TAV 89.7%,CVB and CChMVd infection rates were as same as 66.7%.2.Two kinds of tea chrysanthemum with severe virus infection 'Qiyuebai' and 'Fubaiju'were used to virus detection for 8 kinds of common virus in chrysanthemum,family.By nested PCR and further BLAST analysis,'Qiyuebai' was infected by three kinds of virussuch as CVB,TAV and CSVd,while'Fubaiju' was infected by two kinds of virus as CVB and CSVd.3.Five groups of MS medium with different concentrations of 6-BA and NAA were set up.Each groups of medium was inoculated with 15 'Qiyuebai' and 'Fubaiju' stem apex meristem(repeat 2 times),to select the most suitable hormone concentration for the growth of stem apex meristem.The most suitable medium for 'Qiyuebai' and 'Fubaiju' was MS medium with 6-BA(1mg/L)and NAA(0.1mg/L),in which stem apex meristem growth was the most robust and the highest rate of recovery.4.Using the methods reported in the literature,the 'Qiyuebai' and Tubaiju1 were detoxificated by low-temperature combination with ribavirin method,and the detoxification effect was detected.12 virus-free 'Qiyuebai' seedlings were obtained,and 8 virus-free Tubaiju' seedlings were obtained,and a large amount of detoxified seedlings were propagated.5.At the DNA level,the genetic stability of the detoxified seedlings and the tissue culture seedings were analyzed by the selected 16 pairs of SRAP primer.The results showed that there was no significant difference in the genetic locus between the detoxified seedlings and the tissue culture seedings.The results showed that the 4?low temperature treatment combined with ribavirin had no significant effect for the genetic stability of Qiyuebai' and 'Fubaiju',and the detoxified seedlings all could keep the genetic stability.