Molecular genotyping of Trapa bispinosa and T. japonica (Trapaceae) based on nuclear AP2 and chloroplast DNA trnL-F region

 Premise of the study: Two marker systems were developed for the molecular identifi cation of three Trapa species based on the length variation of nuclear AP2 and trnL-F chloroplast intergenic spacer region.  Methods and Results: Our marker systems analyzed 118 individuals among 36 populations from three Trapa species. Trapa incisa was found to have a unique genotype from the other two species. Individuals of T. bispinosa were distinguished from T. japonica because the former had only a single AP2 genotype. Moreover, our results suggest a hybrid status of T. japonica in terms of two bands within an individual. One band was specifi c to T. japonica and the other one shared with T. bispinosa .  Conclusions: Our marker system demonstrates that nucleotide sequence variations can serve as a fast, reliable, and reproducible tool for molecular genotyping and examining the natural hybrid of water chestnut species.