So far GMO's are only focus of attention because they are patentable and make corporations huge amounts of money and allow them to monopolize the markets, a la Monsanto.
I don't get why its a bad thing to make huge amounts of money. I've never read anyone saying that its a good thing the plant breeders DON'T make huge amounts of money. Nor are GMOs uniquely patentable. Traditionally bred new varieties are also patentable. GMO patents are just easier to enforce. Plus they do things that traditional methods don't.
Which brings me back to the topic at hand.
I'm not understanding the significance of this discovery in advancing fruiting plants.
It's saying gene exchange could occur if you plant something like a fig and a papaya together. It's not saying it will definitely occur and nothing about the speed at which it will occur.
My mother always thinks if I graft a sweet orange onto a lemon I'll get sour oranges. I think that's just wishful thinking. What would be the point of grafting if that's true?
I think you're confused. The papers are not claiming that if you graft two plants (or allow them to grow together and inosculate) then one of them will become a hybrid or bear hybrid fruit. The papers are saying that there are some individual cells or a sliver of tissue
at the graft site that becomes hybrid or fused or exchanges genetic material in some way. When that tissue is cut out and propagated by cell culture techniques it can be an entirely new fusion species.
The significance is that its a new technique for getting plants with mixed genetic material. Traditionally natural crosses, new variants, were discovered in the wild or garden. This was enhanced with isolation, hand polination etc. But still limited to crosses between compatible plants and species. Recently this has been extended with cell culture techniques that can for example rescue a fertilized embryo that wouldn't otherwise grow into a plant because of some growth incompatibility of the parents. (There are other techniques too, like playing with polyploidy to establish compatibility between species that otherwise aren't. And probably many other techniques I'm ignorant of.)
This new result supplies a method of generating "crosses" of possibly any two plants that are graft compatible. And since graft compatibility is much much broader than fertilization compatibility, the potential for new crosses is tremendously increased. Its as if they discovered a new method of cross pollinating plants. Imagine being able to cross species across a whole family, like we already do with the citrus genus (a narrower band taxonomically). Imaging generating crosses between apples, pears, quinces, loquats and hawthorn. Or across the stonefruits even more so than already. And of course what's already been mentioned, i.e. crossing for hardiness or disease resistance, e.g. papaya with babaco. Or how about some giant sequoia crosses? Its known to rootgraft with other species.
I think the potential is amazing.