no, you did not include the maternal tissue surrounding the seed
no, it could be any of the three
Plausible but not proven and needs a lot more data and tests to determine
Highly unlikely, reduced or removed astringency probably depends on directly inherited recessives
Additional information: the cotyledons are typically called endosperm and are usually triploid with 2 copies of the genome from the female parent and once copy from the pollen donor. The germ is diploid with one copy of the genome from the female and another from the pollen donor. The seed coat is maternal tissue that does not normally share any traits with the germ or endosperm. Tissue surrounding the seed including the vascular bundles that feed the seed as it grows are maternal tissue. Seed born effects from pollen most often affect the germ and endosperm (maize). Rarely, it affects the maternal tissue including in some cases the entire ovule (plants that exchange chemical signals between the mother plant and the growing embryo). Have you noticed that a poorly pollinated apple may be lopsided, small, or drop from the tree? These are examples of xenia and/or metaxenia.
I didn’t include “maternal tissue surrounding the seed” because the published research that I’ve read states that the seed produces the ethanol / acetaldehyde, not the maternal tissue. It seems unlikely to me that experts know that the seed produces ethanol but not what part of the seed. Meanwhile, the maternal tissue is treated like a by-stander.
OK. Is any one of these possibilities more likely? Like, I don’t know but I suspect that the seed coat is passive.
Yes, of course it’s unproven. I’ll settle for “plausible.”
OK but how do you explain the JT-02? Does the fruit merely appear PVNA but really isn’t?
This question relates to @PharmerDrewee’s observations above. Has anyone else used a PVNA to pollinate a PCA? Has the seeded PCA fruit shown any signs of PVNA dynamics – for example, early loss of astringency, brown flesh?
@JustPeachy – Done. I get it. See my response. I have a JT-02 fruit on a graft. I think I actually published pictures a couple weeks ago. Here are two pictures taken 10/23.
flavor wise they are very similar except for slightly higher sweetness/honeyed flavorof JT02. But that might be individual variation.
NG is more firm when ripe. JT02 is softer.
NG fruit seems slightly larger.
I think We all should cross the heck out of JT-02 every chance we get. It is super cold hardy, late to leafed out in Z5 so don’t have to worry about late frost and very tasty. Use both Hybrid males and Kaki males. It got good parentage.
It would seem especially promising to cross with a male Kaki PCNA, which would produce some hybrid non-astringent offspring.
I’ll repeat my suggestion that we try Taishu, if we can acquire it. Taishu is, of course, the male parent of JT-02. The two main benefits of using Taishu: (1) It is known to produce male flowers, and (2) It has diverse PCNA parentage (Fuyu, Jiro, x-gosho).
