Plant Hybrid - is a plant variety developed through controlled sexual reproduction of "compatible varieties of plants". Male pollen is transferred to the ovary; fertilizing the ovule. The resulting seed is grown on to see if the plant has specific traits they are looking for.
i.e. Pea Plant A consistently sets pods with 10 peas in it. Pea Plant B is a tall vining plant with slightly pink flowers. The two are crossed to make Pea Plant C that is more ornamental than a regular garden pea, but still produces a fair amount of peas. (I don't know if this plant exists but it seems similar to an experiment and readings I did in plant genetics...lol)
This happens naturally by way of insects and wind and would happen without human intervention. This is done in a lab to limit cross contamination for the plant breeders. But all in all, it's a low-tech way to make new and different plants.
GM Varieties - are developed in a lab, and these plants can use genes from several species (not just plants) using methods such as gene splicing. (They take apart the genetic material and put it back together with different parts). They often use genes from bacteria (and other organisms) and put into the plants genetic makeup. The companies that develop these new varieties (Monsanto is one) claim intellectual rights to these plants so only they can sell seeds. This is a big money and big business.
i.e. A scientist takes genetic material from the bacterium Bacillus thuringiensis which on its own will kill the corn borer, the scientist splices this material into corn to produce a variety resistant to the borer. (This is a real thing.)
As a side note: commodity crops such as corn, alfalfa, soy and sugar beets, canola, have been approved in the US for use, primarily in animal feed and in processed foods (foods which we eat). The exception is sweet corn, which is available fresh at your grocery store.
Now I don't care what thoughts are on either, that's not what this particular defence is about.... but for him to call hybridization a form of genetic modification and lumping it the same as true GM is truly only propaganda from the other side saying that it's all safe...and there hasn't been any long term studies done to determine this. End rant.
And then this was posted at the same time as my response, (and made me feel a little better):