Linnaeus was born 300 years ago. I’m not sure how many species he catalogued in his time, but his 21st century descendants at The Catalogue of Life have reached one million. I checked, and this does include some domesticated plants, but not, I think, in any systematic way. What they seem to have done at the Catalogue is to make it possible for users to search across 37 existing taxonomic databases, so if one or more of those include a particular crop species, you’ll get a hit if you search the Catalogue, and you’ll be directed to the original source of the data.