Analysis on the Genetic Relationships of Hybrid Cymbidium'S Germplasm Resources With RAPD Markers

【Objective】This study researched the genetic relationships of hybrid Cymbidium's germplasm resources at molecular levels,and further obtained information for germplasm storage,utilization,and breeding selection parents for breeding. 【Method】The random amplified polymorphic DNA marker(RAPD) was assessed to detect the genetic relationships among 48 hybrid Cymbidium cultivars from Japan,Korea,China and USA,and 2 species of native Cymbidium. 【Result】20 primers were screened from 100 random decamer primers,and a total of 258 DNA bands were amplified,253 of which(98.1%) were polymorphic. The average number of polymorphic DNA bands amplified by each primer was 12.6. Genetic similarities among the cultivars and species were estimated based on the amount of band sharing ranged from 0.364 to 0.817 with an average of 0.581. According to the data,a dendrogram of genetic relationship which was constructed using UPGMA method showed that all the tested cultivars and species were classified into five cluster groups with the similarity coefficient of 0.592. 【Conclusion】It revealed that the genetic relationships among tested accessions were to some extent related with their origin,flower color,branch type and genealogy. It further indicated that RAPD technique is a useful tool for the studying of genetic relationships among hybrid Cymbidium cultivars.