Dear Mr. Godghate
three provisions of income tax will get attracted to your question i.e. section 27 (i), 56 (2) and 64 (1)(iv)
section 27 (i) says that if any property transferred to you spouse without adequate consideration than transferrer will the the deemed owner of that property. HENCE YOU WILL BE DEEMED OWNER IN YOUR SITUATION.
Section 56(2) says that if an individual or HUF receive gift from relative than it will not be taxable in the hands of recipient of gift. HENCE YOUR SPOUSE WILL NOT BE LIABLE TO TAX FOR SUCH GIFT OF 45 LAC (40 LAC IF SHE PAYS ONLY 5 LAC AS CONSIDERATION)
Section 64 (1)(iv) if any property transfered to spouse without adequate consideration than income from such property will be taxable in the hands of transferer HENCE SUCH RENTAL INCOME WILL BE TAXABLE IN YOUR HAND EVEN YOU GIFTED YOUR PROPERTY TO SPOUSE.
Conclusion :
1. Rental income is always taxable in your hand unless and until she pays full amount of consideration to you.
2. answer given by Naveen CN is good but not foolproof
let me know if i am wrong