Dr. Imago, you have cited three apparently suspicious features of the red-gold 'half-and-half' apple:
- Proportions of the two colours
- Appearance of the boundary
- Colour contrast
I believe your objections are all invalid, and here's why.
First, the colour division is
not half-and-half. In the Telegraph picture it's angled to make it appear almost so, but one of the
BBC pictures clearly shows that's it's not:
In fact, the proportions are very similar to the
Fruit Forum Royal Gala example you posted:
This 1948 paper from the Journal of Heredity, plus
this and
this, provide a crash course in plant chimerism. The points to bear in mind are:
- The apical meristem (which produces onward growth of the shoot, as well as flowers and fruits), is composed of distinct primary cell layers. These are labelled (starting from the outside) as LI, LII and LIII.
- These layers persist to some extent as different regions and tissues in the flower and fruit.
- A mutation can affect one or more of the layers.
- There are different patterns of chimera, depending partly on which layers are involved.
- Horticulturists are especially interested in chimerism within flowers and fruits, as this gives a clue to the derivation of flower and fruit regions from each layer.
- The general pattern is that LI gives rise to a thin epidermis, LII to a subepidermal layer and part of the interior, including the seeds, and LIII to the rest of the interior and the stalk (though my sources aren't entirely in agreement). The skin colour of the mature fruit is usually from the outer region of LII, rather than the thin LI layer.
- However, this pattern is not always followed. Cells from one layer may be replaced with cells from another, in variable regions of the fruit.
From the
Heredity paper:
When a replacement is partial, the changes may be sectorial (mericlinal) and involve areas of various shapes and dimensions.
One type of deviation from the usual development pattern is that the coloured skin can derive from LI rather than LII. A chimera can have part of its colour from each of the two layers, in a segmented pattern:
In rare instances intense coloration appearing sectorially on some fruits, otherwise normally colored, may be taken as due to the presence of a factor for a sport to intense color in the L-I layer.
On the skin of sports with intense colored fruits sharply delimited dull-color sectors have occasionally been observed. In such cases it would seem that such a sectoring occurs when, as stated above, the subepidermal tissue is in part derived from L-I.
The paper gives another example of chimeral segmentation with about the same proportions as our 'suspect' apple:
The fruit appears to be neatly divided into thirds - except that one of the 'thirds' is bigger than the others. In this case it's a deliberately cultivated 'Sweet and Sour' chimera, which is a sport of a (sour) Rhode Island Greening. The mutation is assumed to be in LII, and produces a sweet taste, as well as a growth pattern different from the original type. The author provides a diagram of his suggested distribution of the regions:
As you can see, no hint of five-fold segmentation.
To summarise,
there is no reason to expect the segment proportions to be multiples of 1/5. (Another rather obvious point is that, even if the chimera begins in this proportion, it may not remain so in the mature fruit, as the genetically-distinct segments may grow at different rates.)
Moving on to the appearance of the boundary, it is completely consistent with the Fruit Forum examples (below) - the 'waviness' is very similar:
This can best be seen from BBC image 3:
Here is an enlarged section, (first image), followed by the Fruit Forum examples:
BBC image 2 (unwaxed) shows the russeting to be mostly continuous across the boundary:
As for the dramatic colour contrast, how about this one from the
Royal Horticultural Society? (click
next under the second image). Again, look at the boundary:
And red-gold 'half-and-half' apples are not unknown - I have already provided links to two other cases (though they don't have pictures)
here and
here.
The proportions of the two colours, the details of the boundary and the colour contrast are all perfectly plausible, and (separately) resemble other, indisputably genuine examples - which is, of course, what we would expect if it's a clever hoax!
Dr. Imago, I challenge all your claimed indications of fakery, and I believe I have provided sufficient evidence to refute them. There's nothing in the apple's appearance that points to a fake.
Bear in mind that the grower has been producing apples for decades. If it's a hoax (which I doubt) then he's trying to fool horticultural experts, so it has to be exactly right. I've seen no convincing explanation how it could be done. Nobody has addressed the point that it's a
Golden Delicious (the local agricultural college, which examined it, seems not to have disputed this), so it would have to be
red part that's faked - also there's the continuous russeting across the boundary. In any case, I'm inclined to apply Ockham's razor - it looks like a very rare but natural example of a particularly spectacular chimera - and that's what it probably is.
)
, and that someone is clearly taking the piss).
