@artemis Anthocyanin?
Yes, they do contain that.
Any evolutionary benefit? or just a random byproduct? I like to believe that function dictates form.
Colors are great for birds, etc, I get that purpose - mating, predators, etc. But potatoes? underground?
So, why do they have anthocyanin?
That's an interesting hypothesis.
Perhaps some particular soil ( I guess they r from Peru, Japan?), might require them to have such stress protection. And the difficulty of growing them might be related to soil particularities? Just brainstorming, i have no clue :-)
@artemis I suspect that my temperatures were too hot for the potatoes (I think the original stock came from the Andes, South America). Other times, the area I was in had a lot of fog and the leaves got moldy.