i think someone actually did it, or at least tried to do this.
In theory, it is deffinetly possible. The russian researcher Karpencenko created a hybrid between cabbage and beetroot, so it should be possible to create a hybrid lke a "pomato"
check out procedures of in vitro protoplast fusion and differentiation of callus. it’s complicated, but well figured out

The pomato or tomapot (also called) wasn’t a successful experiment (the result of the cross didn’t produce any benefit) because the researchers didn’t obtain the best characters (so the most "useful" genes) from both species.

It is possible to obtain new plant hybrids from crosses between species (this is one of the objectives of Plant Genetics). A very important example of experiment is this: Triticale (Triticum x Secale).

Is it grown in fild some where in any country??? For market pupose,
I will like to taste that….

Yes, there are Triticale crops in Colombia, Ethiopia, Brazil, Kenya and some parts of the Mediterranean basin. Triticale is well-adapted to acid soils.

Is it(Triticale)= Pomato???

No, Triticale is the result of crossing Triticum and Secale (wheat and barley). Pomato is the result of crossing Lycopersicon esculentum and Solanum tuberosum (tomato and potato).

So where do pomatos are taken???

I heard that pomatoes experiment was unsuccessful so there aren’t pomatoes crops in any place.

Ok…. I got It……..Thanx….

I remember it because I still haven’t got over my Vegetal Genetics notes, he he.