Screening of a core SNP set for the seedling identification of Saccharina japonica cultivars in northern China.

Kelp is an economically important seaweed species in China. The verification of Saccharina japonica cultivars is crucial for industrial development. Four Saccharina japonica cultivars with distinctive characteristics that are widely used in China were selected. To distinguish these cultivars, a highly informative core SNP marker set was identified and validated from 441,094 SNPs. The marker set consisted of 247 core SNPs that were uniformly distributed and were abundant polymorphisms. The similarity between samples was calculated using both core and total SNPs, and a significant linear correlation (P < 0.01) was observed, with a correlation coefficient of r = 0.99. These results provide a valuable SNP set for distinguishing the germplasms of four Saccharina japonica cultivars and serve as a reference for variety differentiation.