Apples cannot grow on guava trees without scientific intervention!

Why Compatibility Matters

The fact that grafts between incompatible trees fail, often immediately, is widely understood, but the mechanism behind this failure is harder to see. At the cellular level, two trees are attempting to communicate and merge their vascular systems to make a single structure. No exchange of DNA takes place, but the rootstock does require similar cells for a healthy connection. The bud forms a callous on the cut side almost immediately as the rootstock's xylem cells are at work attempting to grow over the bud. After several weeks, the bud is completely surrounded by the rootstock's tissues, and the nutritional transport systems begin to join. If the rootstock finds tissues that it cannot communicate with because of cellular or chemical incompatibilities, the graft fails and the bud dies from starvation.

Now of course scientists are trying to find out which plants are compatible for the graft to succeed.

In many instances, grafts between different species have varying success rates; in general, the more distantly related the species, the lower the odds of grafting success. Grafting within a genus is often successful, but within a family success is unusual. Exceptional instances include the Solanaceae (tomatoes, potatoes, and tobacco) and cacti families, which often graft successfully within their respective families .

Some plant species are incapable of grafting to themselves, such as monocots, whereas other plants cannot be grafted to each other but can be grafted to a common third plant, giving rise to a grafting process called double‐working. 

Incompatibility is presumably quite common between unrelated species and is straightforward to identify due to poor growth or death. Because toxins are produced/released due to stress and cell death and the grafts wither and  die. 

Now, let us watch the video very carefully. 

When I put some unused fruit parts in my flower pots, they shrivel within one day. Here in the video even after the plants had grown for a few days, the fruits didn't shrivel. Strange.

Moreover, once the seedling starts growing, the fruit disintegrates. Here in this video , it didn't!

When you put fruit parts in soil, the microbes in the soil will disintegrate the fruit parts, but here they didn't, interesting!

When I put a small piece of guava some years back in my garden, several seedlings originated from it as it contained several seeds. Here only one seedling germinated, when there are several seeds inside the half-cut guava fruit. Funny!

We don't see any apple leaves as apple seeds didn't germinate at all.

When the growing guava seedling comes across the apple fruit, it thinks it is nutrition and nutrient exchange takes place, not genetic exchange.

Apple fruits cannot grow on guava trees just like that without "future scientific intervention". Period!

Now don't get excited! This is not possible and these are fake videos.