Original system change and maintain versions in Target system

In dual landscape i.e.

1. Production landscape – D1 -> Q1 -> P1
2. D2 L landscape D2 -> Q2

Now if we change original system in D2 to D2 , then if transports move from D1 to D2 , if any new versions exist in D2 , they will be retained.

What is the way to retain versions in D2, please suggest ?

The idea is , not to lose the version and retain them , so that prev version and current version can be retrofitted.