**3. Conclusions and future directions**

The results obtained in the present study suggest that the SNP-combination method has high reliability as it utilizes the sequence data. Computational handling of SNP data can be easily carried out so that analysis among many varieties could be easily performed with digital information. Other SNPs identified in the future could be used as additional identification markers. Therefore, using this method, enhancement of accuracy and repeatability in the variety identification could be accomplished in a relatively simple manner.

As SNP-rich DNA regions are only 0.6–1.5 kb in size, they are much less likely to be damaged during the processing of hop products. However, upon degradation and fragmentation of the SNP-rich regions, newly designed primers for the shorter fragments generated might be useful for the amplification of the fragments and may contain several useful SNPs which can be used as identification markers.

The SNP-based information could be also used for quantitative determination of the ratio of variety mixture. In the future, more accurate results will be obtained by using quantitative real-time PCR and/or NGS, which may provide a huge amount of sequence data and increase reliability.
