Crossing Black Beauty, have questions

[MOinMichigan]

Now that I've finally got healthy plants in full bloom here in Michigan, I'm going try crossing a couple favorite heirlooms that have excellent pedigrees and stability with a (presumed, got it from a market) Black Beauty, mostly because it's an interesting, robust, gorgeous plant with dark stems and truly black fruit. Very curious to see the results. Does it matter which plant I choose for the mother?

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[Frosti]

I'd advise you to select father and mother in such a way that it's apparent early on if the cross was successful or not. In the case of a cross between a potato leaf plant and a regular leaf plant, I'd choose the potato leaf plant as the mother. The successful cross will always be RL but only with a PL mother will it be apparent that it worked. If you're crossing two RL plants and one has anthocyanin while the other doesn't, then choose the plant with no anthocyanin as the female parent. Anthocyanin appears to be partially dominant, meaning you'll see antho in the offspring, but not as much as with the inbred parent.

[MOinMichigan]

I'd advise you to select father and mother in such a way that it's apparent early on if the cross was successful or not. In the case of a cross between a potato leaf plant and a regular leaf plant, I'd choose the potato leaf plant as the mother. The successful cross will always be RL but only with a PL mother will it be apparent that it worked. If you're crossing two RL plants and one has anthocyanin while the other doesn't, then choose the plant with no anthocyanin as the female parent. Anthocyanin appears to be partially dominant, meaning you'll see antho in the offspring, but not as much as with the inbred parent.

That's very helpful! Thank you. One of the plants is pink PL and the other is orange RL, so I'll use each of those as the mother and the black RL as the father.

[Pippin]

I would advice not to use pink in such a cross. The reason is that the clear skin has a defect in the anthocyanin formation pathway. This is not reported or documented anywhere (that clear skins would give poor results) but if you dig up the antho biosynthesis pathway from the literature and compare that to what is missing from clear skin tomatoes, you soon realize that there is a blocker in clear skin that may mess up with the expression of black colour in the cross. Similar thing than not to cross yellow and beta if your goal is orange tomato, for example, because yellow blocks beta carothene formation.

I would use only yellow skin tomatoes in a black cross, especially if your goal is to breed true black tomatoes. I am not saying you would not get any black expression in the skin with clear skins, just that it might give you better results to use yellow skins in my opinion.

[Frosti]

I would advice not to use pink in such a cross. The reason is that the clear skin has a defect in the anthocyanin formation pathway. This is not reported or documented anywhere (that clear skins would give poor results) but if you dig up the antho biosynthesis pathway from the literature and compare that to what is missing from clear skin tomatoes, you soon realize that there is a blocker in clear skin that may mess up with the expression of black colour in the cross. Similar thing than not to cross yellow and beta if your goal is orange tomato, for example, because yellow blocks beta carothene formation.

I would use only yellow skin tomatoes in a black cross, especially if your goal is to breed true black tomatoes. I am not saying you would not get any black expression in the skin with clear skins, just that it might give you better results to use yellow skins in my opinion.

Very interesting, didn't know that!

[MOinMichigan]

I would advice not to use pink in such a cross. The reason is that the clear skin has a defect in the anthocyanin formation pathway. This is not reported or documented anywhere (that clear skins would give poor results) but if you dig up the antho biosynthesis pathway from the literature and compare that to what is missing from clear skin tomatoes, you soon realize that there is a blocker in clear skin that may mess up with the expression of black colour in the cross. Similar thing than not to cross yellow and beta if your goal is orange tomato, for example, because yellow blocks beta carothene formation.

I would use only yellow skin tomatoes in a black cross, especially if your goal is to breed true black tomatoes. I am not saying you would not get any black expression in the skin with clear skins, just that it might give you better results to use yellow skins in my opinion.

I had no idea! Thank you! I do have a red PL I can use instead. Slightly different growth characteristics but it still will be interesting. I'll let you all know how it goes! This black fruit is really black, so I'm curious to see how those genes express themselves.