Landrace papayas?

I know there has been some genetic modification of papayas and if I'm not mistaken it has mainly had to do with trying to combat diseases caused by mono-cropping. So I'm thinking what is needed is greater genetic diversity and some efforts at landrace papayas. It is a little too cold in the winter here for them to survive without a greenhouse which I plan to build. Does anyone have seeds from even some less desirable heirloom or wild papayas that could be used to add some genetic diversity to the mix?