Research In RAPD Marker To SCAR Marker In Camellia Sinensis

Tea plant(Camellia Sinensis) is one of the important economic plants in China, which has long history and distributes widely.The germplasm resources of tea plant are very rich.However,tea plant is a perennial cross-pollination ligneous plant,so it has many difficulties in general genetic research.DNA molecular markers can provide accurate and reliable genetic markers for the tea plant.So they play an important role in the research of genetic diversity and the identification of high-quality varieties.In recent years the development of RAPD marker has been widely used in the study of tea plant breeding and genetic diversity.But RAPD technology was influenced easily by conditions,and repeatability and stability was poor.So in the future the development of specific PCR markers will become one of the new research directions in tea plant molecular biology.SCAR marker is one of new molecular markers based on RAPD technology.Compared with other markers,it has such merit as low price,high stability,site-specific and so on.It could improve the efficiency of breeding assisted by molecular markers and be applied in the rapid analysis of a great deal sample.The SCAR technology in rice,corn,rapeseed,wheat and other crops has made some success,but the development and application of SCAR technology in the genetic breeding of tea plant just started.So the research of SCAR marker in tea plant breeding could be enhanced in future.In the experiment,10 tea cultivars from Anhui Agricultural University were extracted their genomic DNA by modified SDS method.The Study was to evaluate their genetic diversity by optimized RAPD reaction system.The specific fragment of 1185bp,498bp and 1622bp was amplified by Random primer S234,S89 and S4 in Longjing-long leaves,Baihaozao and Fuyun-6,named CY1185,BHZ498 and FY1622. According to their sequence the specific primers were designed on the basis of original random primers.SA1/SA2 was the specific primers of CY1185,SB1/SB2 was the specific primers of BHZ498,and SC1/SC2 was the specific primers of FY1622. When annealing temperature was 55℃,SB1/SB2 could amplify stably in the genomic DNA of tea plant.When annealing temperature was improved to 60℃,SA1/SA2 and SC1/SC2 could achieve stable amplification.Other conditions of reaction have not changed.Amplification with these three pairs of specific primers in 10 tea cultivars has obtained the prospective results.The only one amplified band was obtained with SA1/SA2 in Longjing-long leaves,acquired with SB1/SB2 in Baihaozao,and attained with SC1/SC2 in Fuyun-6.These three pairs of primers have no corresponding amplified band in other tested materials.The stable and reliable results which repeated many times showed that RAPD marker has been transformed successfully into SCAR marker.A feasible way of RAPD marker into SCAR marker in tea plant was attempted in the study.It could keep the identification function of germplasm as original molecular markers,and improve stability and reliability of molecular identification.So it could make the application of molecular markers in identification and production of the tea plant germplasm become easier to popularise.It will show applied prospect in reasonable exploitation and utilization of the tea plant germplasm resources.