Crossing tomato noob question.

[maxjohnson]

How important it is to decide which should be the male and which the female plant, and does it matters at all?

Thanks.

[Ann123]

I've been wondering about that too.
I read somewhere on a blog (forgot where) that it doesn't matter but that it is easier to take the plant with a visual recessive trait as mother. So if you cross a yellow mother with a red father you should see red fruit in the first generation. If you see yellow fruit it got self pollinated.

[dfollett]

Originally Posted by Ann123

I've been wondering about that too.
I read somewhere on a blog (forgot where) that it doesn't matter but that it is easier to take the plant with a visual recessive trait as mother. So if you cross a yellow mother with a red father you should see red fruit in the first generation. If you see yellow fruit it got self pollinated.

Ann is correct. Another example that would tell you if the cross was successful very early is a Potato leaf mama and a regular leaf papa. If the cross is successful, the F1 will be regular leaf. If the F1 is potato leaf, the plant is a self of the mama instead of a cross.

If you made the same cross with the RL as the mama and the PL as the papa, the F1 will always be RL and you wouldn't know if the cross were successful until you grew out the F2s. If the cross were successful, 1/4 of the F2s would be PL.

Other than that, there would be no difference in future generations.

[Ann123]

Thank you. Maybe I read this on your blog?
I think this summer I will try for the first time to make a cross.

[bower]

Well.. it is not entirely true that the choice of mother doesn't matter in all cases. That's because some traits (which may or may not be important to you) are more or less strongly affected by maternal DNA - that is, mitochondrial DNA and chloroplast DNA, which come only from the mother plant. I've read for example that specific traits including earliness, cold tolerance, potassium metabolism and even sweetness of the fruit can be affected by the mtDNA and cpDNA of the mother. As I understand it, it may be more difficult to recover the trait if it is coming from the pollen donor instead of from the mother plant. Not to say impossible, but you may end up having to grow more plants perhaps? I actually noticed this effect in some of my breeding lines, and had to go back and reconsider a backcross using an early mother, where the earliness I hoped for didn't turn up in the F2. It was easy to find early plants in that cross!

So it can sometimes matter.

[dfollett]

Originally Posted by bower

Well.. it is not entirely true that the choice of mother doesn't matter in all cases. That's because some traits (which may or may not be important to you) are more or less strongly affected by maternal DNA - that is, mitochondrial DNA and chloroplast DNA, which come only from the mother plant. I've read for example that specific traits including earliness, cold tolerance, potassium metabolism and even sweetness of the fruit can be affected by the mtDNA and cpDNA of the mother. As I understand it, it may be more difficult to recover the trait if it is coming from the pollen donor instead of from the mother plant. Not to say impossible, but you may end up having to grow more plants perhaps? I actually noticed this effect in some of my breeding lines, and had to go back and reconsider a backcross using an early mother, where the earliness I hoped for didn't turn up in the F2. It was easy to find early plants in that cross!

So it can sometimes matter.

Thanks for the correction and clarification, Bower. I'm a noob also.

[BigVanVader]

We should turn this into a noob breeders thread, cause I'm doing my first crosses this year as well and this stuff is very confusing to me. I'm so ADD I have to read everything over and over before I understand it.

For example, how do you know what traits are recessive vs dominate? Also is there a good book that would be helpful?

[crmauch]

Originally Posted by BigVanVader

For example, how do you know what traits are recessive vs dominate? Also is there a good book that would be helpful?

The list someone already posted is good, but can be overwhelming as there are a tremendous number of 'genes' found, but most of them are minor or useless except for scientific study. Also note that a number of genes and there 'allelles' recessive forms used to be noted by capitalization for the dominate genes and lower case for the recessive and early genes were named for the their dominate type (like R for Red-flesh). I've notice that in some cases the way things are noted have changed. Now genes are usually named for the recessive form and the dominate form of the gene is noted with a plus symbol (+). So the gene that controls determinate growth versus indeterminate is labeled as sp (for self-pruning) and the dominate form of the gene (which is the indeterminate form) is sp+.

Two good books to start with:

"Breed Your Own Vegetable Varieties: The Gardener's and Farmer's Guide to Plant Breeding and Seed Saving", 2nd edition by Carol Deppe (although I liked the 1st edition better)

"Plant Breeding for the Home Gardener: How to Create Unique Vegetables and Flowers" by Joseph Tychonievich

Neither is solely about tomatoes.

Chris

[Koala Doug]

I appreciate everyone's comments in this thread. It is nice to get a 'Noob Breeding 101' course here at Tomatoville!

[tpeltan]

Originally Posted by crmauch

The list someone already posted is good, but can be overwhelming as there are a tremendous number of 'genes' found, but most of them are minor or useless except for scientific study. Also note that a number of genes and there 'allelles' recessive forms used to be noted by capitalization for the dominate genes and lower case for the recessive and early genes were named for the their dominate type (like R for Red-flesh). I've notice that in some cases the way things are noted have changed. Now genes are usually named for the recessive form and the dominate form of the gene is noted with a plus symbol (+). So the gene that controls determinate growth versus indeterminate is labeled as sp (for self-pruning) and the dominate form of the gene (which is the indeterminate form) is sp+.

Two good books to start with:

"Breed Your Own Vegetable Varieties: The Gardener's and Farmer's Guide to Plant Breeding and Seed Saving", 2nd edition by Carol Deppe (although I liked the 1st edition better)

"Plant Breeding for the Home Gardener: How to Create Unique Vegetables and Flowers" by Joseph Tychonievich

Neither is solely about tomatoes.

Chris

I am not sure, but I think Carol Deppe has some notes about tomato breeding (and de-hybridizing F1 varieties) in her book The Tao of Vegetable Gardening (but I don´t have the book to check it).

Another easy-to-understand book about plant breeding (in general, no tomatoes) is HAYES, Herbert Kendall a Forrest Rhinehart IMMER. Methods of plant breeding. New York: McGraw-Hill, 1942. McGraw-Hill publications in the agricultural science.

I know, it is veeeeeery old, but it includes basic principles you need for basic breeding (combinatory breeding) explained in clear way.

[Ann123]

Thank you, Bower. Very interesting. Since earlyness and cold tolerance are important for me (living in a cool climate) I should the plant with those characteristics as a mother.

[bower]

BVV no worries, we are all reading it over and over again.
There are some good resources online for tomato genetics. For example this list of known genes:
http://tgrc.ucdavis.edu/genes.html
As regards recessive or dominant, you'll find the dominant traits by convention start with a capital letter, recessive with a small letter, as you scroll down the list.

So for example...
Beta - for beta-carotene orange fruit, is dominant written with a B

sp - "self pruning" aka determinate, is recessive.
pl potato leaf, gf "green flesh" , these common concerns are all simple recessives

But what is more complicated, some traits that are "additive" aka "QTL"s or "quantitative trait locus" iirc, may look like recessives but they aren't really.. If it was all Mendelian with no linkages either, it would be so much easier... but you wouldn't get as many surprises, and they can be good. Surprises can be the best part.

[bower]

I love reading about other peoples' projects so I hope you all keep us posted on your new crosses this summer!

[BigVanVader]

Thanks bower. Here is another question. I'm growing a bicolor det. from Joseph Lofthouse. It is early and cold tolerant. If I crossed your cross with that, then backcrossed the F2 back to yours. Wouldn't that increase the odds of finding the det/early/black fruits/earthy flavor genes? I'm going to do several different crosses this year.

[Fred Hempel]

Back-crossing clearly would favor the traits of the parent you are back-crossing to.

It also delays for another generation the process of developing a true-breeding line.

But, if you have a very specific set of traits you are looking for, back-crossing is very, very helpful.

The other approach to stacking a bunch of traits into one line is to take a hybrid approach. If you have a few true-breeding parents that can contribute the traits you want, making a number of hybrids is another way to try to construct a line with all the traits that are most important to you.

The hybrid approach does require probably 4-6 prospective parent lines. But, for example, if you had 6 lines that you though might be good parents you could easily make 20 unique crosses.

But, using a hybrid approach does require that if you want to have recessive traits show up in the hybrid, you will need both parents to be recessive.

Originally Posted by BigVanVader

Thanks bower. Here is another question. I'm growing a bicolor det. from Joseph Lofthouse. It is early and cold tolerant. If I crossed your cross with that, then backcrossed the F2 back to yours. Wouldn't that increase the odds of finding the det/early/black fruits/earthy flavor genes? I'm going to do several different crosses this year.