A question about hybrid seed saving.

[Kassaundra]

Okay I know if you save seed from a hybrid you may not get a true offspring (could be the same, could be worse or even better) just luck of the draw. Say you do choose to save seed from a hybrid, you grow that plant and it is a great plant, now if you save seed from that one will it come true? ( I mean true to the second plant, not the original grandparent plant)

 

[digitS']

Maybe a diagram of a Punnett square would help:

What to say about it . . . um, this shows the parents each with differences and their offspring. Both parents are heterozygous. And, they cross and produce offspring - some of which are heterozygous and some, not.

Now, you must have been happy with the hybrids, right? That large "B" is what you were seeing in them. It was a genetically dominant characteristic. And, you allowed them to produce the 4 offspring. At least one of those you had in the garden this year. And, you are happy again with that plant's characteristic. But, how do you know whether you have a "Bb" or a "BB" . . ? You don't. You are only seeing that dominant B.

I believe that you might just be back to this Punnett square next year if you plant your seed. You won't know if you are planting something where the desired characteristic is just being expressed because it is dominant or if you have lucked out and drawn the homozygous straw - the BB. If you have Bb seed, at worst, you are back where you were in the spring of 2011.

This is just the simple situation where only one gene controls the one genetic characteristic. And, it has been just a year or 2 since I enrolled in those 1960's biology classes. And as someone once said, if you think you can remember anything from the Sixties, you are just kidding yourself.

Steve

 

[Kassaundra]

I only planted non hybrid this year, but was just curious if there was a generation down the line in hybrids where you get like offspring. This is my first year to do any seed saving at all.

 

[catjac1975]

For a plant such as you describe you would have to be sure that it was self pollinated. In the case of squash you would have to hand pollinate, then tape the blossom shut to prevent cross-pollination. However if you have had such an occurrence I would save and use the seed anyway, unless space is at a premium.
a hybrid can be 2 inferior plants that happens to produce a superior offspring.
But, I am all for the surprise factor in gardening.

 

[seedcorn]

Assuming you "self" the plant, it takes about 6-7 generations to make a true line. While the simple AA X BB theory is correct, understand that you are talking about several thousand genes. If it were simple, plant breeding wouldn't be a profession dominated by phd's with $$$$ of equipment. For us hobbiest to actually make a good line, we need a lot of luck as well as patience. I'm not saying don't do it, just enjoy it for the process.

 

[ninnymary]

I have always been curious how the seed companies keep producing the hybrids to be true. For example, the early girls. How do they keep hybridizing them to always come out the same?

Mary

 

[momofdrew]

I have wondered that too but that is why they get the big bucks... for the most part I stick with heirloom tried and true seeds

 

[digitS']

The seed company

owns

the parent lines.

They tend them carefully and grow them every year in field B and in field b. Every year, they carry some of the pollen from the father's line . . . . over . . . . to some of the mother plants. Offspring -- the seeds -- are sold.

Steve

 

[ninnymary]

Thanks Steve for the clear explanation. But what about bees? Won't they pollinate some from B to B, or b to b? Are these hybrids planted in an open field or green house?

Mary

 

[digitS']

Mary, it is my understanding that plants like squash have to be separated by MILES to lower the risk of those pesky bees moving pollen around! The seed company may contract with a farmer but there must be a way of certifying that the field is properly isolated.

Tomatoes, peas & beans are mostly self-pollinating because their flowers are closed. The plant breeders could "close" the flowers by putting bags over those used for seed production.

Something like 99% of our corn in this country is hybrid, according to Wikipedia. You can imagine how it would be fairly easy to hybridize corn. Just plant 2 varieties closely together, maybe every other row, or so. You could go thru and cut the tassels off the mother plants and leave the tassels on the father plants. At the end of the season, collect the seed from the mother plants.

You know, some of the hybrids have been around for many years. The parents of Golden Cross Bantam were brought together by Purdue University in 1933 and the seed first sold in 1934. Those parent lines would have to be maintained all these years and by most definitions, they'd be heirlooms, too. Their hybrid offspring . . would probably still be looked at with suspicion by some folks.

Steve