Evaluation of SNP fingerprinting for variety identification of tomato by DUS testing

Abstract

Variety identification is crucial for PBR (plant breeders’ rights) protection and PVR (plant variety registration). DUS (Distinctness, Uniformity and Stability) testing, utilizing field-based morphological inspection and DNA fingerprinting with molecular markers in the laboratory are commonly employed methods for variety identification. However, the limited number of molecular markers used in DNA fingerprinting often lacks close linkage to DUS traits. In this study, 116 tomato varieties were well identified both by SNP fingerprinting and DUS testing. PCA (Principal Component Analysis) and population classification demonstrated a highly consistent outcome between SNP fingerprinting and DUS testing, resulting in the division of 116 varieties into three groups: big fruit, cherry, and processing tomatoes. Furthermore, we selected a new set of 16 core SNPs and 18 core DUS traits, which exhibited higher efficiency in variety identification due to their convenient and easy processing. Moreover, the observed variations in SNP markers among each pair of tomato varieties were linearly correlated with those comparison of all different DUS traits (R² ​= ​0.85), and the linear correlation was also obtained based on the comparison of different core SNP fingerprints with those of the core DUS traits (R² ​= ​0.86). In conclusion, we evaluated SNP fingerprinting for variety identification in comparison to DUS testing, and found these two methods had consistent result. This study also highlights the potential of limited core DUS traits and core SNP fingerprints for effective identification and discrimination of tomato varieties.