Hi Kang, thank you for checking. The grower clearly said they are different in size, color and the time of blooming.
Here is the screenshot of my conversation with the grower and vendor.
Hi Bill, the seller has no idea what he’s talking about.
Biqi is very dark - I’ve had Biqi and dongkui fruits in both US and China. The pic in the chinese document above about Biqi also shows very dark fruits. Biqi and dongkui are the two most widely grown varieties and are very distinctive.
Dongkui is large (largest of all common varieties), red to red/black, sweet but with some tartness.
Biqi is much darker, medium/small size, sweet with less tartness.
I never heard of male trees w/ varieties. They should be based on male seedlings (either male seedling or scion from a male seedling grafted onto seedling). As you know Yangmei don’t come true to seeds.
Anyway don’t want to be negative. You are doing a great job - I just don’t think the seller knows about the varieties. If he’s really a grower I’d ask him to show pics of his trees, leaf patterns, and fruits.