If hybrids produce seeds that aren’t ‘true-to-type’, then how do they keep making the same ones every year?
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Now that your question was answered in great detail, you should read or watch something about apple genetics. These trees have a genetic mechanism which ensures that their offspring will never be the same as parents. And thus all commercially grown apple trees across the world are clones. And always were.
If you cross AA males with BB females, you get all AB babies (“hybrids”).
But if you cross AB males with AB females, you get a mix of AA, AB, AB, and BB babies.
If you want to reliably produce lots of AB babies every year, you need a reserve population of true AA and BB breeding stock.
And that’s with just one gene. A specific breed or landrace can have lots of distinct genes.
This! The breeder basically keeps two parental lines that they use to make the seeds. Usually they need to do the crossing pollination by hand somehow and make sure that no foreign pollen fertilize the females. There is a great and accessible book about breeding by Carol Deppe if you’re interested in breeding plants in generally https://www.chelseagreen.com/product/breed-your-own-vegetable-varieties/
I’ve also always been wondering about this and other questions before reading that book.
Thank you for the reply. I’ll check that out
So when the breeder has a hybrid they like, let’s call that AB (F1), they want to grow and sell more of that variety. So the following year, they will use their reserve population of true AA and BB parents and hand pollinate them. But they still won’t know if the seeds produced will be anything like AB (F1), right? So are those hybrids only available for 1 year or as long as those original seeds remain viable?
True Hybrids (F1) will be identical. But the catch is that you can’t have a “true hybrid f1” if your parent lines are not true breeding. Usually this involves selfing the parental lines 6+ times to obtain purebred (all genes the same allele) lines.
Lots of breeders are loose with that step, so you can occasionally get some variation in your F1. But that’s usually because selfing 2 parents 6+ times, then making the hybrid cross is at least 7 generations. In an annual crop, or even biannual (onion/carrot) this can take 7-14 years.
You’ve underestimated it by a bit. It takes 2-3 generations to increase the inbred seed quantities after selfing. So figure 20 years. Plus the female line takes 5 generations to create so another 10 years (onion hybrid seed production requires 3 lines: Male, maintainer & female - the female has cytoplasmic male sterility). All together it used to take 30 years to create a new female line.
Today onions are self-pollinated traditionally for 2 generations, then double-haploids are produced. It takes another 2-3 generations to create the female line with marker-assisted back-crossing. It takes 2-3 generations to create enough parent seed to produce commercial hybrids. So say 12-16 years now for a female line. 10 years for the male and maintainer.
Hahaha!
I was trying to keep it simple enough to answer OP about vegetables in general. But you are correct with regard to onions. I actually work for a vegetable breeding company, but I try to stay vague enough to protect my anonymity. It’s a pretty small word in the plant breeding community. (Even smaller in veg seeds specifically.)
You know your stuff, so I’ll have to assume you work for one of our competitors. And based on nothing other than assumptions made in bad faith, I will now consider you my lemmy nemesis.
Edit: wait… it’s somehow BOTH of our cake days? Are you actually me?
What the heck is happening here? I thought everyone on Lemmy was in tech but you two are both plant breeders and you both came to Lemmy on the same day? That’s bananas.
Thank you both so much for this information. It’s kind of confusing actually! I thought I was asking a question with a simple answer but that’s not the case at all.
That’s what I’m sayin! Goofy ass world we live in. Either that or me and “v” are the same person, and we have split personality disorder and can’t remember the password to each others lemmy accounts…
Shout out Oregon, btw.
I got out of vegetable seeds about a decade ago. My tendency to make the brown-nosers look absolutely stupid became a liability once I hit upper management. Imagine a plant breeder with a talent for computers, logistics, marketing and sales. I asked all the “wrong” questions.
Currently running my own seed dealership/research activities for row crops.
Damn. That’ll happen.
Nice work getting out of the business. Corporations can really crush your soul. I bailed on my plant breeding background because I prefer the data side.
What kinda seed you selling these days?
Just about anything except vegetable seeds.
Field corn, alfalfa, cereals, hay grasses, forage crops, turfgrass, covercrops, native grasses, flower seed etc. I never quite know what I will be moving next.
Seeds of many species, when stored correctly, can still germinate for decades. I have used seed that was 30+ years old several times before.
Breeders produce inbred parental lines by self-pollinating for 5-8 generations (or double-haploid creation).
They then do a small initial seed increase by bulking a generation. Bulking refers to combining the seeds from several plants (I used nethouse with 24 cantaloupe plants and a small young queen honeybee hive inside to produce 0.5-1kg of seed).
This is called basic or breeder seed. This lot is tested for genetic uniformity and seedborne diseases. It’s also used for small hybrid seed productions to test out the inbred.
Breeder seed is increased again and bulked to make foundation seed (around 50kg for cantaloupes) This is used to make the first commercial production of the hybrid. It is then increased yet again to produce stock seed (500kg)
Stock seed is what the commercial hybrid is produced from for the rest of its life. Foundation seed is used to produce more stock seed as needed.
The breeder seed and foundation seed are stored carefully to prolong it’s life. The stock seed is in the general warehouse with the hybrid seed.
As long as they maintain quality control during the inbred increase process, the resulting hybrid will always be essentially the same.
Oh that’s amazing that they can get the same results each time. Like if my wife and I tried to make 8 children that all looked the same that would be impossible.
