I have tried this and obtained mixed results. Some come out normal photo period plants, some come out auto flowering and some come out somewhere in between. My conclusion was that it produces too much instability with the offspring, at least in the F1 generation and I would not do it again. In fact I have become anti auto flowering plants in general, mainly due to unstable genetics and generally poor yields and lower THC content, all whilst using too much electricity if growing indoors. And as an outdoor grower, they make no sense at all!
Ruderalis, to me, is a dirty word!!
Hope this helps,.... Organoman.