Genetic variability of cultivated Chaenomeles speciosa (Sweet) Nakai based on AFLP analysis

Amplified fragment length polymorphism (AFLP) analysis was performed to evaluate genetic relationships among 52 Chaenomeles speciosa accessions grown in China. A total of 208 polymorphic markers were generated from eight selective primer pair combinations. Genetic variations were remarkably observed in a wide range of dissimilarities, percent polymorphisms, and average polymorphism information. Genetic similarity values were calculated using Jaccard's coefficient between individuals of different flowering quince accessions; these values ranged from 0.296 to 0.931 with a mean of 0.597. Cluster analysis and principal coordinate analysis were then performed on the basis of AFLP profiles. In our generated dendrogram, accessions were clustered into seven major groups. Mantel's test was performed to determine cophenetic correlation (r = 0.9); this result indicated a very good fit of the dendrogram. We conducted analysis of molecular variance and found greater variations within cultivars than among cultivars. AFLP analysis results further revealed relevant information regarding the genetic background of flowering quince accessions essential for future breeding programs related to plant improvement.