At this time we do not have a validated protocol for prepping seeds for testing and we do not accept seeds as a sample type for genomic services.
We have not yet developed a reliable/scalable protocol for extracting gDNA from seed. The primary reason for this is that we want avoid testing, genotyping or sequencing the endosperm. The seed coat of cannabis seeds, as in most flowering plants, is Maternal DNA. The Megagametophyte in the seed (endosperm) is pollinated with a different pollen than the Embryo.
See here for more detail: https://genomebiology.biomedcentral.com/articles/10.1186/gb-2002-3-9-reviews1026