Seed coat DNA content is very small, electrophoresis may not be able to detect it, but PCR is different, with high sensitivity (it can be amplified by millions of times), and finally it is normal.

If it can be detected by PCR, it means that the genomic DNA extraction is successful, regardless of the result of direct electrophoresis.

If we have to make the genome electrophoresis detectable, we can try to extract it in large quantities first, and then concentrate the extracted genomic DNA, which may take ten times or more to be detected by electrophoresis.