Does anyone have any idea what percentage of apples, pears, cherries that sort of thing grows true from seed or is it all just chance ? Is there a way to tell what will and won't grow true from seed ?
Apples and pears notoriously will not come true to seed. My experience with stone fruit… watching an Ume plum seed escaped from compost to outside the containment, bearing fruit 3-4 years after sending up initial shoot, several seasons observation, fruit was indistinguishable from it kin in the field. Others on this forum are much studied and may correct me. I think from what I’ve seen and can tell, that variety’s like Italian and native plums in general will come very close to ‘true’ from seed. The more hybrid crosses seems to me would be more subject to reversion favoring one or another of the parents. ‘Improved’ prune plums I’m not sure that they’d stabilize. Pluots come to mind, probably not as I think about it.
Rooney, you’re likely the most deeply studied stone fruit go-to that I know on this forum, I’m pretty sure you have some of the concise skivvy on the subject.
My experience is similar to that of James. Apples and pears, pretty wildly variant. Hollywood plum seems to come true. Most of my Asian plums don't. Pawpaws are pretty close to parent. In general: the wilder the fruit or berry, the less varied it is and the more likely it will come close to the original. The more bred it is, the less likely it will come true to seed.
@ James: I glean stone fruit breeding inheritance factors about half from books and the other half secondary word of mouth information from those that test clones at dedicated farmers which are educated from the breeders.
@ amiart: Domestic apricot breeders find the cultivar 'orange-red' to contribute good fruit size very reliably. The race of hunza apricots that average a late season flowering has 'zard' as a reliable contributor to late season flowers.
Reports on cherry say that when the most productive cultivar or race that is raised up as a female parent, then the offspring are very productive.
Reports on all fruit trees from studies completed at Austria Michurin Insitute have proven that female trees pass along knowledge to the offspring seedlings a memorization of how long growth should occur before hardening off for winter to avoid loss or even death. The pollen contribution to memory is nulled out. This one is a good case of gene silencing. Other studies indicate that the seedlings can re-learn new environmental changes while yet young trees. In a sense it makes sense for certain bird carried fruits that are discarded elsewhere like cherry to rely more on learning and less from what mother knew.
When there is a graft it became revoked the idea that DNA is carried across the graft union. Clarity happened when they discovered the responsible agents were cross plant communications in the form of micro-RNA molecules that are manufactured in various different places for each type in any particular tree or plant.
Outside of plants, even a virus is known to make these same molecules. In the case of M9 you had a dwarf apple tree when grafted upon M9. When they found that M9 had a virus, they produced new M9 virus free rootstocks, of which now were not M9 dwarfed trees anymore.
A lot has to do with how complex the heritage of a given fruit type is, and how much it has been modified from the "wild form" of the species. Part of this has to do also with how many hundreds or thousands of a years a fruit has been cultivated and selected for better, larger forms.
Fruits that I have grown from seed and been throughly happy with (when I lived in southern California) include apricots (Prunus armeniaca) and loquats (Eriobotrya japonica). These apparently have not been as extremely selected away from the wild forms as other fruits. Things like pears and apples have a very long history of being selected by humans for desirable traits, and growing them from seed is a tremendous gamble in terms of what you might get among the progeny. That being said, fruits from a commercial orchard will probably be pollinated by another "modern" commercial apple; consequently, your chance of getting something at least edible is higher than in a random cross. Apples, too, have a very complicated genetic history because they were often transported to new areas and consequently interbred with whatever the locally native crabapple species was. Preserving a particular clone of apple by grafting allowed some beneficial or desirable genes to be carried through the centuries. Grafting of favored clones goes back at least to the ancient Greeks and Romans, and who knows how much further back. It is now generally conceded that the origin of our "modern" apple goes back to the Tien Shan region of central Asia, which just happened to be along one of the "silk roads" of trade between east Asia and the Near East and Mediterranean cultures.
Controlled hybridizing may have some rewards, if you want to pursue it. Crossing one of your favorites with another of your favorites might not get you quite to what you fantasize about, but it puts you on the right track to potentially get a seedling of merit (at least to your own tastes). I've hybridized plants for most of my life, in part because I'm fascinated by genetics, and also because I love to see the progeny of a planned cross in order to better understand the genetic inheritance of various features in that particular group of plants. The observations provide a lot of information about the plant group.
I've blathered as usual. I hope that at least some of this is relevant and or helpful.
P.S. -- If you want to hybridize quinces (Cydonia oblonga), I suggest big tasty variety crossed with big tasty variety. I have a "wild type" quince that I've grown for years and the fruits -- at maturity -- look like hairy, yellowish-green golf balls. Quince was probably domesticated in the Caucasus Mtn Range, and the "modern" form has come a long way from the wild.
Addendum to my last post (--sez the guy who just won't shut up),
Those hairy, yellowish green "golf balls" are also rather "woody". I would classify them as "edible in no way."
A number of years ago, I attempted to assess the percentage of daylilies (genus Hemerocallis) that were bred and produced by Arlow Burdette Stout nearly a century ago. As near as I could tell, out of the literally thousands [at least] of crosses among the daylily species, he apparently only found about 1 in a thousand that he considered worthwhile such that they were worthy of naming and introducing. Granted, he was working from the "raw" species that he acquired from east Asia.... Nowadays, coarse, leathery flowers of tetraploids are all the rage, no matter how muddy the colors might be. The diploids still retain the gracefulness of the original species. [...This latter commentary brought to you by "the guy who just can't shut up".]
Hence, given how far apples and pears have come, I still recommend that you cross one of your favorites with another of your favorites in order to increase the chance within the seedling progeny that at least one or two approach what you envision, and want, and can be "worked with" further". My wife often kids me saying that she wants to make me a T-shirt that says: "TAKE IT TO THE F2!''. In a cross between two stabilized varieties one tends to get + or - an intermediate version between the parents. That's the F1 (first filial) generation. To "shuffle the cards again", you need to cross one promising F1 plant to another F1 plant of the same parentage to really begin to see re-segregation of the countless genes that affect every aspect of the plant's growth and characteristics. It's often in the F2 (the 2nd filial generation) that you find progeny worth crossing again to approach the ideal that you envisioned. Needless to say, that kind of hybridization is a heckuva lot easier when you're dealing with annuals or biennials. The length of time that an apple or pear takes to reach fruitful maturity can take several years. That's where it's helpful to start hybrid apple or pear seedlings, then graft those to a dwarf or semi-dwarf rootstock to speed up the system. After all, we have limited lifespans. We're lucky that we've already received such a rich heritage from our ancestors.
I hope that this is helpful info.