The first intergeneric cross between bread wheat and rye was made by

The first intergeneric cross between bread wheat and rye was made by Rimpau.
The first 'true' allopolyploid triticale according to today's definition was bred in 1888 by the famous German plant breeder W. Rimpau who managed to create a cross between wheat and rye that was partially fertile.
When crossing wheat and rye, wheat is used as the female parent and rye as the male parent (pollen donor). The resulting hybrid is sterile and must be treated with colchicine to induce polyploidy and thus the ability to reproduce itself.