Question: Graft

About 2 years ago I bought an apple tree, and I was wondering how else I could graft it, they advised me to use a pear tree that belongs to the same family (or even a peach). I would like to see the tree with mixed pink and white blossoms, I have been looking for a list of apple trees compatible with fruit trees for a while, but I can't find it, would you be so kind as to tell me which tree is the most suitable? I take this opportunity to remove a doubt and also ask, if possible, what determines the formation of a hybrid with both parental characteristics (such as mandarin orange), is it a matter of codominance, incomplete dominance or other? What can I do to obtain a hybrid rather than the coexistence of both parental species? Thank you very much for your kind attention

Answer: Graft

Dear Marco,
most of the fruit plants that are grown in the family orchard are rosy, so theoretically all the plants could be grafted together, so in theory you could graft a peach onto your apple tree, so as to get a branch that produces peaches, and one that produces apples, which otherwise ripen at different times, and therefore you can have a fruiting that lasts over time.
It is not said that all grafts take root and are therefore successful.
Usually hybrid fruit plants are grafted on very vigorous varieties, or particularly resistant in adverse climatic or soil conditions, in order to obtain better fruits, or ones that ripen earlier, or plants that develop and bear fruit even in conditions unfavorable to their development . In general, hybrid varieties are grafted onto plants obtained from seed, whose fruits would be of no value; therefore it tends to graft apple trees on apple trees, peach trees on peaches, etc .; only the pear trees are often grafted onto the quinces, which seem to give more fruit and vigor to the plants.
To be more successful you could try grafting two different varieties of apple trees on the same rootstock.
However, consider that your apple tree is almost certainly the result of a graft, and therefore it would be advisable to graft the new plants onto the rootstock, and not onto the branches already grafted.
The issue of hybrids is different: a hybrid and a grafted plant do not have much in common.
As we said before on a seed plant, plants with particularly interesting fruits are grafted, these plants are all hybrids, that is obtained from the crossing of different species of the same plant, and therefore if obtained from seed they would not produce with certainty identical fruits to those of the seed. plant that produced the seeds.
The hybrids are not obtained by grafting, but by cross-pollination, and consequent seeding of the seeds contained in the fruits obtained, and subsequent cultivation of these seed plants.
Generally, when a plant with particularly interesting fruit is obtained by hybridization, it is subsequently propagated by grafting, so as to certainly have fruits identical to those of the mother plant.
It is not easy to obtain hybrid varieties that contain the characteristics of two different fruits, since the fruit plants grown today are already all hybrids, obtained by crossing other hybrid plants, so it is not easy to understand the relationships of each single plant, and it becomes difficult to cross plants further.
In addition to this cross-pollination with fruit plants does not always happen, that is, it is easy to get seeds by pollinating two different types of cherry, while seeds are not obtained by pollinating the flowers of a cherry tree with the pollen of a peach tree, as these two plants, although both belonging to the genus prunus, have been so much cultivated over the millennia, that their kinship has been diluted over time, so much so that they become very different.
As for citrus fruits, the question is different, as these plants tend to hybridize naturally, without human intervention, so most of the citrus species we cultivate are actually naturally created hybrids, such as lemon and lemon. 'Orange.