Saturday 23 February 2008

Commercial F1 hybrids

Rants are like buses. There had to be another one round the corner.

It's been nearly two years since I wrote a post about F1 hybrids, and with the seed-buying season now underway it seems like a good time to revisit it.

If you browse through almost any seed catalogue, even those of ethical and responsible companies like the Organic Gardening Catalogue, you will see a lot of varieties with 'F1' next to their name. Most vegetables, with the exception of peas and beans, are extensively offered as F1 hybrids. There is a good reason for this: they are extremely profitable for the companies who produce and sell them. Sometimes they have benefits for gardeners too. But there's a catch. Well, several actually.

Commercial F1 hybrids are produced by environmentally dubious methods and they often need chemical inputs in order to grow properly. They're expensive, and they force gardeners to keep buying more packets year after year because you can't save true-breeding seed from them. They effectively curb the centuries-old sustainable practice of seed-saving and replace it with a cycle of marketing.

There is nothing wrong with F1 hybrids in themselves. They are the first step in every plant breeding project. When I breed my peas, I make my own F1 hybrids by hand-crossing different varieties and then use the resulting genepool to select potential new varieties. Nature creates F1 hybrids all the time, which is how plants evolve and diversify. It's a natural, wholesome and vital process. The problem lies in the commercial abuse of it.

The basis of F1 hybrids' popularity is hybrid vigour, or heterosis. When two dissimilar varieties are crossed, the result is a hybrid which will often be bigger, brighter, faster-growing or higher-yielding than either of its parents, which makes for a great selling point. But it's a one-hit wonder. Subsequent generations don't have the same vigour or uniformity, and the idea is that you don't save seed from it, you just throw it away and buy some more. This is bad for the plants, bad for the garden and bad for you, but the seed companies make a packet out of it and gain increasing control of what we buy and grow.

In my opinion, hybrid vigour is slightly overrated anyway. There's no doubt that F1 hybrids can produce abundant crops in the right circumstances, but so can natural open-pollinated varieties. You can make more of a difference to a crop's performance by providing decent growing conditions than by buying "superior" seed. I'm not convinced that the benefits of F1 hybrids are worth the costs.

One of the costs is that it's part of a push to industrialise seeds, giving corporations more control of what we grow. Industrialisation also involves taking seed production and plant breeding out of the field and into the laboratory, with patented technology increasingly seen as the path to profit. It's easy for me as an amateur plant breeder to condemn these practices, and I do understand how hard it must be to make a living from natural plant breeding - I don't expect to be financially compensated for the hours of work I put in on mine. But I still don't like the way things are going.

The problem in producing F1 hybrid seed commercially is that it's expensive. Hand-pollinating flowers is not difficult in itself, but it's time-consuming. One solution is to have the work carried out in countries where skilled labour is cheap. That may work with tomatoes, where hand-pollination is easy to do and a single pollination produces a large amount of seed. But it ain't much use with things like carrots, where the flowers are so tiny that hand-pollination is practically impossible. The only way to make F1 hybrids economically viable is to use Cytoplasmic Male Sterility (CMS).

The simplest application of CMS is to find a naturally-occurring gene for male sterility and breed it into your target crop. The plants are unable to produce their own pollen, which makes it easy to pollinate them en masse by exposing them to pollen from a different variety. Instant hybrids, in whatever quantity you want.

However, not all plants have been obliging enough to offer a male sterility gene, so it has to be done forcibly. One way of going about it is to use chemical sprays to prevent pollen being released. Another is the patented technique of protoplast fusion, where leaf tissue cells from different plants are fused (either with electrical current or chemicals) to transfer the male sterility attributes from one species to another. It's a method of forcing the transfer of genetic material between plants which don't naturally cross, although at the moment it only works with related species. The resulting plant tissues are tetraploid (i.e. they have double the normal number of chromosomes) and are propagated in the laboratory. It's not the same thing as GM, because it's a joining together of two complete and separate genomes rather than splicing genes from one genome into another. But some argue that it is a form of genetic engineering and should be labelled and regulated as such.

There are other problems with the production of commercial F1 hybrids. The parent varieties will usually have been inbred to an extremely unhealthy degree (because a lack of genetic variability is crucial to the uniformity of the resulting hybrid). Extreme inbreeding goes against nature and reduces genetic diversity. CMS (even in its "natural" form) has problems ... a male sterility gene used in maize hybrids happens also to convey susceptibility to a form of corn blight, which nobody realised until the blight started wiping out crops on a huge scale. Hybrids made by CMS sometimes produce sterile seed, so you couldn't save and replant it even if you wanted to.

But perhaps the most simple and straightforward objection to F1 hybrids: they are extremely poor value for money. Here's a few examples from the 2008 catalogues I happen to have lying around on my desk (try it for yourself):

Tomato Roma (non-hybrid) £1.99 for 75 seeds = 2.65p each
Tomato Suncherry Premium F1 £2.99 for 6 seeds = 49.83p each

Carrot Yellowstone (non-hybrid) £1.99 for 1500 seeds = 0.13p each
Carrot Purple Haze F1 £1.99 for 300 seeds = 0.66p each

Cauliflower All The Year Round (non-hybrid) £1.25 for 250 seeds = 0.5p each
Cauliflower Concept F1 £2.75 for 30 seeds = 9.16p each

Pepper Oro (non-hybrid) £1.49 for 45 seeds = 3.31p each
Pepper Attris F1 £3.09 for 5 seeds = 61.8p each

You will notice that catalogues disguise the price difference by varying the quantities in the packet. You may not worry too much about the difference between a £1.85 seed packet and a £2.85 one, but when the cheaper one contains 100 seeds and the expensive one 5 seeds, that's a huge differential, and one which they're hoping will slip beneath your radar. It's daylight robbery.

There are three ways you can help reduce the stranglehold big business has on garden seeds:

1. Boycott F1 hybrids, by choosing only non-hybrid varieties when you buy seeds.

2. Dehybridise them yourself: call the seed companies' bluff by saving and sowing seeds from F1 hybrids and selecting the best progeny, to create an open-pollinated version of the hybrid.

3. Make your own F1 hybrids. It's easy and fun!

Tomatoes are particularly suitable for home-made F1 hybrids. Choose any two non-hybrid varieties (the more unalike they are, the more fun the results) and when they are both in flower cross them manually (here's my easy guide to hand-pollination). Even from just two or three hand-crossed fruits, you can save enough seed to provide you with more than you can grow. Given that tomato seeds can easily stay viable for 10 years, if you like your hybrid you can keep sowing the seeds from the original cross for many years without having to redo the cross or save seeds from the hybrids.

There's never been a better time or a better reason to become an amateur plant breeder!


Matron said...

Fascinating stuff! Very topical for me.. I bought a packet of a new Thompson & Morgan F1 tomato called 'country taste'. £2.99 and it contained just 6 seeds! All of which have failed to germinate. I am going to send them back and demand a refund. I love the idea of making my own crossbreed. How does Sungold x Marmande sound?

Rebsie Fairholm said...

Sungold x Marmande sounds like a great idea! They're both esteemed for their fabulous flavour. I think Sungold may itself be an F1 hybrid (one of the few genuinely good ones) which would make for some interesting and variable results but you never know what you might end up with. There's nothing to lose by giving it a try.

Anonymous said...

That's funny we were just posting about similar things at the same time. I made my post before I came over here and read yours.

Rebsie Fairholm said...

What's even weirder Patrick, I just discovered your post and was writing you a "what a coincidence!" comment just at the very same moment you were commenting here! Synchronicity or what?

Anonymous said...

Great post Rebsie, I missed it earlier but came across it today doing some searching on F1. I got sent F1 seeds by Chase Organics (Sweetcorn Sweetie with only 50% germination). I only realized they were F1 once I received the seeds as they were not labeled F1 on their website.

I am intrigued at the idea of breeding a new variety, never tried it before but it sounds exciting and worth a shot.
Thanks for putting up such good information

Unknown said...

What's even more amazing is that the success rates for germination of commercial seeds in my hands are considerably lower than germinating the seeds I made myself last year.

I got 100% germination rate with my own seeds and under 80% with some commercial ones.

My plants are more vigorous than the commercial ones to date.

Given that you can buy a 500ml concentrated seaweed extract for £5 - 10, this appears better value for money than buying expensive F1 hybrid seeds.

I must say I buy F1 plants from nurseries to eliminate that issue. They usually take a couple of weeks to nurture back to health as mass production tends to leave them dessicated and still in pots too small for the plant size.

My feeling on making my own hybrid is to find a cold-tolerant strain to cross with Alicante. Alicante does great in the warmth, but is pretty temperature sensitive, so hardening it off is a bit risky.

Scott Plant said...

If you don't like F1's, go ahead and plant the inferior seeds you get from the F1's. Thats the alternative. It's the same thing. Hybrids are are bred to improve over the parent plants. If a Hybrid has a low germination rate,it is beacuse of the grower not the seeds. One of the traits hybridizers are looking for is ease of germination. Hybrids sell, inferior seeds/plants don't.

Anonymous said...

I have read that many alleged hybrids are not hybrids at all, and just labeled as F1 so that people will be discouraged from saving seed.

I would like to save seed because purple carrots seem to be only available as F1 hybrids, but am worried about the protoplast fusion thing. Can you tell me whether the male sterility is linked to all foreign plant material, i.e. whether a dehybridized, non-sterile plant will be free of any GMO material?