Do lycopene and the various purple tomato anthocyanins share the same precursor chemicals, or are they pretty separate pathways? They’re starkly different chemicals, but you never know sometimes what shares what in plants. Basically, would the white tomato gene that knocks out lycopene also knock out the potential for developing anthocyanins? I’d also be curious to know to what extent it’s recessive or dominant. You’ve mentioned even just grafting to a red tomato restores some color to white tomatoes, so I guess there’s some pretty fragile epigenetic stuff going on that might not inherit very well.
From the above, I guess it’s already pretty clear what I’m considering, but to sum up, I’d like to give a shot at crossing a white with a purple variety to try and knock out the orange/red lycopene while keeping the anthocyanins.
Regarding the other topic, I recall reading that Sungold’s own seedlings don’t even match Sungold, so I guess it’s got a pretty rare combination going on. To the extent that other tomatoes even have fruity, tropical flavors going on, do any of them seem to pass that on better than Sungold does? Sungold has been around for a little while now, so it’s surprising to me that folks haven’t made any progress with it or similar tomatoes.
Anthocyanin is on a different biopath and is produced as a protective chemical against intense sunlight. Anthocyanin to a tomato has roughly the same purpose as brown pigments in our skin from sunlight exposure. Many anthocyanins have a disagreeable flavor.
Purple tomatoes such as Cherokee Purple have a gene that prevents breakdown of chlorophyll. Normal tomatoes convert chlorophyll in the fruit into bits and pieces that are then built back into lycopene. With the chlorophyll retention gene, the fruit turns red with a mix of deep green which turns a brownish shade. We see a “purple” color as a result. Chlorophyll retention tends to affect flavor and sweetness in ways we like. If you go back about 100 years, a single variant plant “Feejee” was found in the Philippines. It appears to have been the first documented occurrence of chlorophyll retention. It is probably not the only mutation which prevented chlorophyll breakdown.
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That makes sense, they’re cousins to tannins if I recall correctly, and are all phenolic compounds at the end of the day.
That’s very interesting regarding Cherokee purple. Is it the same with really dark varieties like Black Krim, or are those anthocyanin colored?
Black Krim and Cherokee Purple are both chlorophyll retention.
Jim Myers at OSU combined 3 genes found in wild tomato species to produce anthocyanin varieties roughly 20 years ago. I made this picture of P20 in my garden nearly 20 years ago. P20 was not officially released due to a bunch of problems with the genetics. Blue tomato - Wikipedia
Since then, GMO methods were used to produce varieties that have anchocyanin all through the fruit as compared with anchocyanins only near the surface. Norfolk Blue is the result.
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