Another Hybrid Question

[NarnianGarden]

I know, I have been boring the tomato gurus to death with my questions... Try to survive one more...

As has been discussed in many threads, the whole crossing business is like genetic lottery, and there are surprises some times... I still don't get it how the breeding companies make sure that the crosses for making hybrids work every time and bring the desired results... But:
Here's the question.. When the final parental lines are crossed for seed production, it's always the same parentage, right? What would happen, if the parents had reverse roles - i.e., instead of using Male X to pollinate Female Y, the breeders use pollen from Y to fertilize X? Would that make a lot of difference, or practically none?
Has anyone ever tried to make these mirroring experiments and reported their findings?
Just thinking about the endless breeding possibilities with that process....

[zipcode]

Yes, reversing the parents does have a small effect, it would not be exactly the same.
And at least recently, there are certain known genes for certain taste profiles, you can 'screen' for them and make sure the most important ones are included. Which is probably why the new grape hybrids taste suspiciously close (and quite different then usual tomatoes) even though they come from very different companies.

[carolyn137]

Originally Posted by NarnianGarden

I know, I have been boring the tomato gurus to death with my questions... Try to survive one more...

As has been discussed in many threads, the whole crossing business is like genetic lottery, and there are surprises some times... I still don't get it how the breeding companies make sure that the crosses for making hybrids work every time and bring the desired results... But:
Here's the question.. When the final parental lines are crossed for seed production, it's always the same parentage, right? What would happen, if the parents had reverse roles - i.e., instead of using Male X to pollinate Female Y, the breeders use pollen from Y to fertilize X? Would that make a lot of difference, or practically none?
Has anyone ever tried to make these mirroring experiments and reported their findings?
Just thinking about the endless breeding possibilities with that process....

With modern hybrids there are two breeding lines,let's call them A and B

Start each of them with a known OP that has been selected for breeding,and breeders do have special ones they use,and then do line A separate from line B

In line A introduce a trait,whether it be a disease tolerance one,or high solids or even ripeing genes,etc.

Then check what you have to see if indeed that gene was incorpated.

Using that line A one,do it again with a different gene,check it, until you get to the final one in line A and that's usually after 4 parental inputs

Do the same with line B.

Then cross the two final ones to form the hopefully stable hybrid. Sothe final F1 should have 8 total parental inputs.

I know of only one circumstance where parentswereswitched andthesewerejusttwoparentscrossed donwbytanleyZubrowski in Canada andhe had sent me four crosses he had made with Brandywine,crossed with an early variety,I remember Glacier and Stupice were two of them, and then he switched parents and did it the other way. So he sent me 8 crosses.What he was trying to do was to introduce better taste in some early varieties.

I put out plants from both types of crosses and could see no differences

But I do remember reading somewhere that mitochondrial DNA could make a difference,and I'll let those here who know much more than I do speak to that issue.

Carolyn

[travis]

Originally Posted by carolyn137

But I do remember reading somewhere that mitochondrial DNA could make a difference,and I'll let those here who know much more than I do speak to that issue.

Carolyn

"Which plant one chooses for a male and which for the female often has little consequence for what most of us are trying to achieve. [IE Stupice x Brandywine vs Brandywine x Stupice (called a reciprocal cross)]. There is what is called the maternal effect. This is the result of DNA present in the chloroplasts of the mother plant (called cDNA). Cholorplasts from the mother plant are transferred to the developing embryo via the ovary. Embryos do not receive cDNA from the male. This can be utilized by plant breeders but most of us would not be aware of such differences and reciprocal crosses to make F1 hybrids USUALLY are fairly similar. If you have time/room, try both."
http://www.kdcomm.net/~tomato/Tomato/xingtom.html

When I first started cross breeding tomatoes, I used potato leaf varieties as the seed mother and regular leaf varieties as the pollen donor simply to be able to readily tell at the seedling stage whether my cross took.

Another thing I did next, whether or not I selected a potato leaf variety as the seed mother, was to select as the seed mother the variety whose blossoms were the easiest to emasculate, and subsequently to which apply pollen, without breaking the pistil.

Also, I tend to choose as the seed mother the variety whose fruit produces the greater amount of seed.

I have never successfully done reciprocal cross pollination and then tested by comparison the resulting germplasm, so I cannot speak to that.

I'm more interested in accomplishing crosses that input known and obvious characteristics, so after accomplishing a successful cross of two varieties, I move forward by selecting the segregations and recombinaitons that intrigue or please me, then possibly backcrossing to accentuate target characteristics, or outcross to input additional characteristics.

Also, with limited space, reciprocal crossing for me would just mean devoting valuable space to examine negligible variations. But that is just my opinion from a hobby breeder's point of view.

[Fred Hempel]

I don't know about "the breeding companies" but I assume almost the opposite. Finding a hybrid that "works" takes many attempts.

For example, I am trying to produce a hybrid this year with a certain color and stripe pattern and some other important characteristics including decent shelf life. To do this I have made over 50 crosses because I know that many of the hybrid combinations will be good but not great. Hopefully I have enough combinations, so that one or two will really stand out. If not, I will try again next year.

Making hybrids is not about simply adding new varieties to the tomato pantheon. It is only worthwhile if the outcome is exceptional, because if there is an OP alternative, most people will not pay for the hybrid.

Originally Posted by NarnianGarden

I still don't get it how the breeding companies make sure that the crosses for making hybrids work every time and bring the desired results.

[NarnianGarden]

Interesting. Thanks!
I'm thinking of the well-known hybrids and whether the breeders ever tested a reciprocal cross to compare the results taste-wise or in regards to other characteristics. (not sure if that would still be considered the same hybrid - Big Beef for example)

[NarnianGarden]

Originally Posted by Fred Hempel

I don't know about "the breeding companies" but I assume almost the opposite. Finding a hybrid that "works" takes many attempts.

For example, I am trying to produce a hybrid this year with a certain color and stripe pattern and some other important characteristics including decent shelf life. To do this I have made over 50 crosses because I know that many of the hybrid combinations will be good but not great. Hopefully I have enough combinations, so that one or two will really stand out. If not, I will try again next year.

Making hybrids is not about simply adding new varieties to the tomato pantheon. It is only worthwhile if the outcome is exceptional, because if there is an OP alternative, most people will not pay for the hybrid.

Again, I was regerring to mass production of well-known existing hybrids. (SunGold, Sweet Million, etc etc) I have read that they have quality controls, and have ways to ensure everything stays in line, but when processing thousands, and even millions of seeds, I am sure there might be just that one that is a free thinking rebellious mutant

Speaking of exceptional, there are many many red and yellow hybrids in British seed catalogues... I don't know if it's especially an UK thing, but gardeners there seem to love hybrids. Do all the countless red and yellow slicer / cherry tomato hybrids taste unique? Perhaps, but I am doubtful...

[AlittleSalt]

I wish the (rules of thumb) were somewhat different. Instead of crosses taking the smaller shape/size we could have a Sungold the size of a Big Zac

[NarnianGarden]

A giant SunGold..? That would be something
Enough for that pasta sauce recipe I have seen in the internet...

[carolyn137]

Stating very clearly that I'm not a guru, but what about male steriles ,and here I'm talking about tomatoes,less you think otherwise.

First the picture page

https://www.google.com/search?hl=en&...24.z15DT6x4Kuk

And now the individual articles

https://www.google.com/search?q=male..._AUIBigA&dpr=1

I'm know that they are now being used for commercial breeding,note the mention of some commercial varieties in Narnian's post above above,and they have been used for maybe a decade now.

So how do they enter this picture of breeding,especially for commercial breeders?

Would using some of the parthenocarpic ones developed by Dr.Bagget be of use in a breeding project help since I doubt that most here at Tville who do breed tomatoes have access to male steriles.?

http://t.tatianastomatobase.com:88/wiki/Legend

Carolyn,just thinking,which she doesn't do 24/7.

[joseph]

When I make crosses, I often use the more wild parent as the mother.... Because I want to retain diversity in the organelle DNA. Usually, I can't measure it directly, or observe any changes. Still, I figure that I'll try to keep as much diversity around as possible.

When I first started growing carrot seed, about 70% of my crop was male sterile, due to the maternal-only DNA from the organelles. I started with commercial hybrids which use male sterility as an easy way to create hybrids. Since then, I have culled the male-sterile lines.

[travis]

Male sterile tomato plants are obtained simply by planting a goodly number of F2 seeds taken from an F1 tomato fruit of a variety known to carry the aa-ms10 genetics from one of its two parent lines.

There are several such hybrids created with one aa-ms10 parent, most of which are red grape or "plum saladette" types, aka "roma" style, usually also bred with multiple disease resistances, high crimson, uniform ripening, and improved shelf life/shipping characteristics.

The male sterile plants can be identified by their glassy, pale green, anthocyanin-absent, hence "aa," stems in the seedling stage. There should be approximately 25% aa-ms10 seedlings in a batch of F2 starts from the type of hybrid tomato about which I speak.

None of the glassy, light green stemmed plants will produce pollen, hence "ms" or "male sterile," therefore the breeder may apply pollen to the flowers without first emasculating the blossoms, thereby grossly reducing the labor cost and vastly increasing F1 seed production.

The drawback for the hobby breeder is the carrying forward of the male sterile genetics potentially for several generations of segregation and recombination, and the fact that you cannot sell hybrid seed without the required licencing.

[travis]

(double post)

[Fred Hempel]

I tend to agree with Travis, the reciprocal crosses at times can give different results.

I don't typically to a cross both ways, unless it is a high priority combination, and then I may try it both ways.

Most often, though, I am choosing a female parent based on which parent will make a better female. Sometimes I know from past experience which of the parents will make a better female.

I would assume that particularly once a hybrid is slated for release, a company would compare a cross made both ways. More to figure out how to best produce seed, but they would also be getting information about potential differences (although, I think it would be rare that they see any).

Originally Posted by NarnianGarden

Interesting. Thanks!
I'm thinking of the well-known hybrids and whether the breeders ever tested a reciprocal cross to compare the results taste-wise or in regards to other characteristics. (not sure if that would still be considered the same hybrid - Big Beef for example)