Backcross-Recessive gene transfer

How Recessive Gene is transferred with Backcross Breeding?

Let, variety X is well adapted and high yielding variety.

Variety Y is another variety resistant to a specific disease; which is governed by a recessive gene. We wish to transfer this recessive gene form variety Y to variety X.

So, variety X – recurrent parent (♀)
Variety Y – donor parent (♂)

When the desired character i.e. disease resistance is governed by a recessive gene, back crosses cannot be performed in continuation as in