Intra-specific genetic relationship among 20 cultivars from Camellia japonica based on ISSR molecular markers.

Camellia japonica has various ecological,horticultural and economical uses.An approach was established using ISSR(Inter-simple sequence repeat) molecular makers to classify and analyze the intra-specific genetic relationship among twenty cultivars represented from C.japonica,collected in China and abroad.Twenty-one couples of primer sequences which could amplify clearly and reproducible electrophoresis bands were screened from sixty couples of primers.Using these primers,153 discernible DNA fragment were generated with 146(95.4%) being polymorphic,indicating pronounced genetic variation at the cultivars level;the band in fingerprinting were converted into 0 or 1,where 1and 0 indicated the presence and absence of a band,respectively.Nei's diversity indices(H) ranged from 0.40 to 0.48 and Shannon's information index(I) ranged from 0.57 to 0.67.The gene differentiation coefficients ranged from 0.5 to 0.7 and Nm ranged from 0.2 to 0.5.The genetic similarity coefficients(Hs) among the tested cultivars ranged from 0.50 to 0.74,averaging 0.63.The results showed that the genetic differences among the twenty cultivars were relatively little.Combing the results of flower morphology and UPGMA cluster analysis,we could divide the twenty cultivars into two big groups.There were four cultivars in groupⅠ,which all grows in Zhejiang Province and has red flowers.There were sixteen cultivars in groupⅡ,intra-specific genetic relationship complexity.In addition,the results also showed that ISSR molecular maker was suitable to analyze the intra-specific genetic diversities and genetic relationships of C.japonica.