Alan Ratcliffe wrote
Poplar is actually commonly used for Strat bodies. Very similar in sound and weight to alder. Less desirable than alder as it has a bit less resonance and tends to have mineral streaks in it, which make it unsuitable for transparent finishes.
To add to that
I am sure Mervyn has made solid body acoustics (what we see as conventional) with Poplar bodies...
I have never seen or played on one, so thats as far as my knowledge goes... But I am quite positive he has... I will ask him next time and get some of his thoughts.