GMO and non GMO or F1 etc seeds , question :)

You can save any seeds you like, but they may not grow the same as the parent if they have been cross-pollinated.

Can I ask an F1 question here too please, rather than start a new thread? If you don't get true seed from a plant grown from an F1 seed, then how do they manage to sell packets of F1 seeds?? *very confuzzled *

They cross the parents again, to create the seed. That's why they're more expensive (plus factoring in, all the previous generations to create a stable strain of the hybrid).

Edit: to clarify, by crossing the parents I mean the two types that create the f1 So for a simple example here, say tomato a is red, and tomato b is yellow, and they cross them (fiddly job!) to create tomato c, which is orange - they seed company (or whoever owns the rights to the hybrid, etc) will grow more tomatoes, a and b, and then breed them to create tomato c.

F1 seed is the "first generation" result of a cross between pure bred lines.

So take a Tall plant and a Sweet plant and cross them such that all the Children are Tall and Sweet (wish my kids were like that ... but ... look at the parents, eh?!!)

If you then sow the seed from those First Generation children, i.e. the seed is F2 for Second Generation, you will get a mix of the original characteristics of Tall & Short, and Sweet & Bitter.

The tricky bit is creating the pure-bred lines such that 100% of the F1 seed has the desired characteristics.

Dunno if you did genetics at skool? but in a nutshell it is a result of the DNA having a pair of genes for a characteristic. Lets take Tall and Short (oversimplification as there will probably be several genes governing height). So you have one gene for Tall (T) and one for Short (S) so any particular offspring might have TT, TS, ST or SS. One of the characteristics is Dominant, the other is Recessive - lets assume that Short is dominant. So the TS and ST, as well as the SS, plants will all be short. Only the TT plant will be tall.

If you breed a TT plant with a TT plant you will get TT children (one characteristic from each parent). This is double-recessive - all children will be tall,even if you save your own seed.

If you breed SS with SS you get SS

If you breed TS & TS you will get TT, TS, ST and SS - i.e. only 1/4 (the TT) will be tall, but children from saved seed will be a mix of TT, TS/ST & SS genes, so in general 1/4 will be tall in each generation.

However, if you save all the seed from tall plants and resow in a scientifically controlled way, throwing away the short plants so they don't cross-pollinate, then you will be able to isolate the TT plants over time - several season / generations. Thus, eventfully , you wind up with a pure breeding line, which you can then cross with the pure bred Sweet line to get your F1 seed.

Usually the cross pollination is done by hand, to force only A to cross with B, and each flower is then covered to prevent further cross pollination - hence it is expensive to produce.

If you are not asleep yet?!! well done

Ok I am going to ask a question as well rather than start a new thread. Ok here it goes

pea A + pea B = pea AB F1 (and yes they could all be different from each other)

however at what point do each of the pea AB F1 seeds become their own variety. As in theory peas are self pollinating. To my mind each pea produced from each of the pea AB F1 should come true to the relavant pea AB F1, is that right? (I hope that makes sense)

No, the offspring of the AB F1 will be 50% AB, 25% A and 25% B.
AB F1 can never be a stable variety because of its mixed heritage.

The reason for this is that although the normal F1 plant cells have both chromasomes and therefore both A and B genes, when the pollen (male) and ovule (female) gemetes are formed the chromasomes split apart - these only contain either A or B. Therefore even though the parent is the same when they self pollinate, there is still a mixture of types in the seeds.

When we try to do these sort of discussions we should always consider plants as AA, BB at the very least.

I am not a plant geneticist but I understand peas are a nightmare to work with and that Gregor Mendel only got the results he did because the other (junior) monks knew what he was hoping to prove and cooked the results. (Which shows a very good understanding of biology!)

Let's take this a bit further to show you why trying to save seed from F1 hybrids is not a good idea.

Let's say you are a tomato breeder and you have spent years perfecting a nice, big well flavoured red bush tomato with a resistance to verticilium wilt. Because you have selected carefully your tomato contains the following genes:

BB (big fruit) cc (bush) FF (flavour) pp (red, not purple) RR (resistant to wilt). (These are NOT real genes - I have made this up as an example - something like flavour will be much more complicated, and I have no idea which of these traits is dominant).

Notice that some of these are in capitals (dominant genes) and some are in small letters (recessive) but all are the same - either double dominant or double recessive. There is no genetic variation here - this strain will breed true for all of these charactaristics.

Suppose the tomato breeder wants to breed a purple tomato with these charactaristics. He has a purple tomato that he has bred which is a very nice tomato but unfortunately it is susceptible to wilt, so he wants to create an F1 variety which is resistant. Note that he is only trying to add one of these characters.

The purple tomato has the genes:

bb (its a small tomato), CC(its a cordon tomato) ff (its flavour is inferior to the red tomato) PP (purple) rr (not resistant to wilt)

When you make an F1 cross between these 2 hypothetical plants you will get:
Bb (big) Cc (cordon) Ff (good flavour) Pp (purple) Rr (resistant).
So, PROVIDING THAT the dominant characteristics are the ones you want, you have something that is the best of both worlds. However, if you wanted a purple bush tomato, this is not the right cross, because cordon is dominant in my hypothetical world.

But (if you are still with me) look what happens when you start to cross the F1 hybrids together.
You will get 75% big and 25% small fruit.
Each of these groups will contain 75% cordon and 25% bush - thats 4 different types of plant
Each of these 4 will contain 75% good flavour and 25% inferior flavour - thats 8 types.
Each of these 8 will contain 75% purple and 25% red thats 16 types
Each of these 16 will contain 75% resistant and 25% non resistant - thats 32 types.

Of course the exact arrangement of genes will be different too as some of the 75% (50% overall) will have one of each in any of the groups.

And this assumes that you have charactaristics that are simple dominant/recessive and that one of them completely dominates the other. In real life things like flavour, fruit size etc are likely to be combinations of several different genes and some of them will probably not be completely domminant.

Anyway from my example, saving seed from your F1 big fruited well flavoured purple fruited wilt resistant cordon plant has a finite chance of producing a small fruited poor flavoured non resistant red bush tomato, which is not only exactly what you don't want, its also worse than either of the 2 parent strains.

In real life you are not dealing with 5 variables, but probably hundreds. Its amazing that plants breed true at all!

It's also worth noting that peas don't really cross without intervention so are incredibly easy to save true seed. So in fact pea A will self fertilise and produce more pea A

I was curious and my question was specific to peas as I read the following site pages

Daughter of the Soil: What do you get when you cross a purple-podded pea with a yellow-podded pea?
Daughter of the Soil: How to breed your own garden peas

As you say you have to intervene, but if you only intervene the once what was the knock on effect and how long would it carry on down the line. That was all

No way I could fall asleep. There was just this tremendous whoooosh as it went over my head

Excellent explanation, thanks. I started writing about my (limited) knowledge of hybridizing animal earlier and gave up! Not even coat colour is simple.

I have only ever grown the tiniest number of F1 seeds, (the odd very early courgette or calabrese) thinking that if the world ended then I would be able to save seed even from these if I had to and then be able to select up to something useable but I think that one has been blown out of the water. Obviously, it is going to depend on what the F1 production is for - is it just 2 genes or is it 5?

I do often wonder what some of these F1 plants have over the open pollinated ones other than the profit and "dependency" culture they create.

A really great thread to start the year off

Reliability of the plants grown, compared with OP ones.

I grow just a few, where OP varieties can't give me the exact results that I'm looking for, such as Minipop sweetcorn or club-root resistant cabbages