Studies On Genetic Diversity Of Tea Germplasms [Camellia Sinensis (L.) O.Kuntze] In Guangdong Province By SRAP Technology

The tea[Camellia sinensis(L.) O.Kuntze]breeding and resources preservation depend on the fully understanding of the inherited disorders' amount,distribution and evolution of Gene Tank.It is difficult to study the tea's inherited disorders and evolution by traditional measures such as form and agronomic characters analysis,while molecular marker is an effective instrtument.in studying the genetic diversity and genetic differentiation.In this study,genetic diversity in twenty-five local cultivars of the tea plants in Guangdong province and five contrastive cultivars from different regions were assessed using morphological,SRAP makers for the first time,and the genetic relationship among the accessions was revealed by cluster analysis at various levels.The main results are as follows:In this study SRAP-PCR system was established for tea plant,the reaction of which was composed of Mg²⁺ 3.0mmol/mL,Taq 2.0U,dNTPs 0.2mmol/L,2.0μmol/L of each primer,10×Buffer 2.0μL,20ng DNA in a total volume of 25μL.Primer combinations used herein gave rise to distinct bands with abundant polymorphism,indicating that SRAP could be used for identification of genetic diversity,elucidation of origin and classification of tea plant.Genetic diversity in tea plant was assessed using SRAP makers for the first time at home and abroad,which showed that SRAP was an effective,cheap and dependable marker for polymorphism analysis in tea plant.A total of 127 amplified fragments and 114 polymorphic fragments were detected by applying 21 SRAP primer combinations.The polymorphic fragment percentage was 88.67%.The number of amplified fragments and polymorphic fragments per primer combination were 6.05 and 5.43 respectively.30 tea accessions were divided into four groups of A,B and C at genetic distance of 0.388, 83.33%of which were classified into group A.Group A could also be divided intoâ… ,â…¡andâ…¢sub-groups at genetic distance of 0.314.There were 13 in theâ… subgroup,2 cultivars in theâ…¡subgroup and 10 in theâ…¢subgroup. In summary,the quantitative criteria for evaluating genetic diversity and sampling strategy for genetic resources conservation and utilization of local cultivars of Guangdong province tea plant had been provided,and the results could have been used to guide genetic resources collection,conservation and elite breed selection of tea plant.This study was significant for genetic diversity research and conservation of local cultivars of tea plant in Guangdong province.