Dioecious grape vines

Didn't know best where to put this so I'm dropping it here.  Like many, I've been over-zealous in planting wild grape that I harvested from a local riverbank.  I did not realize that they were dioeceous and I could well have planted only male or only female plants.  What I do know is that some nice looking 3 year old vines haven't produced a single grape, whereas the original stock on the riverbank produced well and abundantly year after year.

Since there has been much advance in the genetic typing of plants for traits like male/female, etc., I was hoping there might be a way to genetically test young plants to make sure I have a good mix of each.  Looks like this is a relatively recent line of study in Vitis..... (below, from an open-access article):

Just adding this nice photo from the article above.  We were too late with our analyses of wild grape stands on the property....the flowers have all but disappeared at this point.  If you have all male vines, then you won't get grapes.  If you have female vines, you will need a male or hermaphrodite vine to provide pollen.  The hermaphrodite vines apparently can self-pollinate.

I've got at least 2 trees I'm growing that both would produce edible nuts if they turned out to be female, but alas, odds are total crap for one and maybe 50/50 for the other (since 9/11 khakis hatched this spring are males, I don't assume 50/50 for anything except coin flips!) It would be great if there were easier ways to determine such things before maturity! It may not be cost effective at the small homestead scale though, but I can wish!