Genetic relationships of Diospyros kaki Thunb. and related species revealed by IRAP and REMAP analysis

A modified method of inter-retrotransposon amplified polymorphism (IRAP) with primers annealing to the conserved reverse transcriptase sites instead of the conserved long-terminal repeat (LTR) regions and retrotransposon–microsatellite amplified polymorphism (REMAP) markers were used to investigate genetic relationships of some Japanese persimmon (Diospyros kaki Thunb.) genotypes from Japan and China and the related species. In total, 117 scorable amplification bands ranging from 250 to 2000 bp were generated by IRAP and REMAP analysis, among which 101 (86%) were polymorphic, with an average of six polymorphic bands per primer combination. The analysis of genetic relationships of 27 genotypes revealed that the Japanese, Chinese genotypes and related species were distinctly separated. The phylogenetic trees constructed by unweighted pair-group method with arithmetic averages (UPGMA) and Wagner parsimony cluster methods agreed well with the geographic origin information. The Japanese persimmon genotypes from Japan and China may have different genetic background, suggesting a long independent domestication, intercrossing and breeding history in both regions. ‘Baogaitianshi’ and ‘Xiaobaogaitianshi’ had a high similarity coefficient, implying that they possibly have the bud sport relationships. The related species were clearly clustered in a separated group, suggesting that they are very closely related.