There are two kinds of "graft hybrid". The better known form is also called a chimera. This usually occur when one species or variety is grafted to another and a shoot grows from the union with cells of both species (or varieties) in layers or sectors. Laburnocytisus adamii is a famous example.
http://www.biologie.uni-ulm.de/systax/dendrologie/labcytadflw.htm

Many green/white variegated Sansevierias, African Violets and Geraniums are also chimeras, though they usually are not produced by grafting.

The other type of graft hybrid is produced by grafting one plant onto another, then raising seedlings from the scion. The offspring sometimes show traits of the stock, even though the scion is from a true-breeding strain. For example, a white-fruited tomato shoot grafted to a red-fruited variety can produce red-fruited offspring even though it was self-pollinated. A tomato grafted to a black nightshade produced some offspring that were far earlier than the self-pollinated parent.

Graft hybrid peppers can produce fruit with different shapes, colors and degree of "heat" than the parent. Branching habit can be altered.

Karl

Here is a link that might be useful: Graft hybrid peppers

I know there are many examples with fruit trees, tomatoes, peppers with grafting.
But I wonder if it is occured with conifers not necessarly between different genera but with different species or varieties.
As many of them are grafted in the trade (rare species or cultivars), it would be surprising that no graft hybrid occurred: perhaps it would be more difficult, I don't know and I am not a specialist; just curious.
I see that graft hybrids appear with plants that are rather easy to graft. Is there a link?
If someone can tell more, I am interested. Thanks