F1 seeds

We often see F1 hybrid seeds in catalogues and, nearly as often, we wonder what exactly they are. Even more intriguing is the question: 'Is an F2 better than an F1?'

The simplest way to define an F1 hybrid is to take an example. Let us say a plant breeder observes a particularly good habit in a plant, but with poor flower colour, and in another plant of the same type he sees good colour but poor habit. The best plant of each type is then taken and self-pollinated (in isolation) each year and, each year, the seed is re-sown. Eventually, every time the seed is sown the same identical plants will appear. When they do, this is known as a 'pure line'.

If the breeder now takes the pure line of each of the two plants he originally selected and cross pollinates the two by hand the result is known as an F1 hybrid. Plants are grown from seed produced and the result of this cross pollination should have a good habit and good colour.

This is the simplest form of hybridisation; there are complications, of course. A completely pure line can sometimes take seven or eight years to achieve. Sometimes, a pure line is made up of several previous crossings to begin to build in desirable features and grown on until it is true before use in hybridisation.

To summarise, an F1 hybrid is the result of crossing two pure lines to achieve the desired result. This seems a lot of trouble to go to but there are definite advantages. Scientific and accurate breeding programmes have made it possible not only to bring out the outstanding qualities of the parent plants, but in most cases, these qualities have been enhanced and new desirable characteristics added to the resultant hybrid plants. In addition to qualities like good vigour, true-ness to type, heavy yields and high uniformity which hybrid plants enjoy, other characteristics such as earliness, disease resistance and good holding ability have been incorporated into most F1 hybrids. Uniform plant habit and maturity, coupled with uniformity in shape or size have made hybrid vegetables extremely suitable for mechanical harvesting.

We can't expect to get all these advantages for nothing. Because creating F1 hybrids involves many years of preparation to create pure lines and these pure lines have to be constantly maintained so that the F1 seed can be harvested each year, the seed is more expensive. The problem is compounded because to ensure that no self pollination takes place, all the hybridising of the two pure lines sometimes has to be done by hand. So you often have to pay more for your seed or get fewer in a packet. Seed is often collected by hand too to ensure that each plant is as productive as possible.

It is not only the gardeners who benefit, there are advantages for the plant breeders too. With ordinary varieties anyone can grow them and collect the seed which can then be re-sown in the garden or, on a larger scale, sold. So a plant breeder who puts a lot of work into creating a variety which is not an Fl hybrid can soon find someone else selling it and getting a share of the financial reward. But seed collected from an Fl hybrid will not produce plants the same as those from which it is collected. Only by crossing the pure lines can the variety be made - and only the original breeder has the necessary pure lines.

So it works both ways. The gardener gets better, though more expensive, varieties and the plant breeder gets a reasonable return on the investment.

It's difficult to tell from the term F2 hybrid whether the plants are an improvement over the F1s or second class versions of them. In fact, it's quite straightforward. In its simplest form, an F2 is the result of saving seed from an Fl hybrid; in other words, it's the next generation.

As I described in a previous article, an F1 hybrid is produced from two pure lines but these could have been developed from a number of parents at various stages and if seed is sown from F1 hybrid plants it is quite possible that you will see not only 'parents' but 'grandparents' in the resulting plants.

Nevertheless in very many instances and in spite of what some seed catalogues may say, F2s will sometimes produce an acceptably high percentage of plants almost identical to the F1 hybrids from which they derive. It could be that the plants are perhaps a little later, slightly taller, and probably lack the uniformity, but nevertheless they produce a very acceptable result.

F2s will also retain a large slice of their parents' vigour and even the disease resistance and other characteristics the parent plants have been bred for. They are also cheaper because the F1 hybrid plants which produce the seed can be grown in a field and mechanically harvested. You will recall that to create F1 hybrid seed each plant has to be hand pollinated and each seed pod carefully harvested. The simple mechanised method of seed production means that seed is cheaper and you get more for your money. Examples of F2 varieties in catalogues include Primula malacoides 'First Love', Calendula 'Neon', Petunia 'Rainbow' and Geranium 'Fleuriste'.
Open pollinated varieties

Open pollinated varieties of seed, sometimes referred to as OPs, are plants which are either self pollinating or cross pollinating with their neighbours but lack the uniformity of either an F1 hybrid or even an F2. They are not subject to the germination fluctuations occasionally found in F1s.

If you happen to see an especially nice plant of, say, an Antirrhinum it is quite simple to save a seed pod, sow the seed the following year and get a plant exactly the same. They are therefore cheap, they can be grown easily on a large scale, mechanically harvested, and as it is usually more robust, cleaned in volume.

Many of our open pollinated varieties of seed today, particularly the flowers, are the result of nothing more than careful selection. Some of our latest varieties are simply the result of plants which have been selected from a large number and grown on in isolation. Sometimes one will see, for example, a delphinium which is very short. There is obviously a good chance that if the seed is saved from this plant, in the next generation you will have a good sprinkling of early flowering short plants and, quite possibly, a range of colours. By continuing to select these plants you will finally establish a crop that is almost entirely early and short. This is probably the earliest and most simple attempt at plant breeding.

For instance, the Salvia 'Splendissima', which is exciting a lot of interest, especially in America, is the result of seven generations of selecting for exactly the characteristics that are required. In other words, each seed now produces a very nearly identical plant and without the expense of creating an F1 or F2.

Examples of familiar open pollinated varieties include: Chrysanthemum 'Court Jesters', Digitalis 'Excelsior Hybrids', Eschscholzia 'Monarch Mixed' and Alyssum 'Carpet of Snow'.

Do not be misled by the publicity which may tell you that only F1 or F2 varieties are worth growing. They are certainly good but an open pollinated variety can still stand on its own feet and strong new plants are still being produced from open pollinated selections.

Remember, you get what you pay for. If you want the best, it's and F1; if you want nearly as good at a better price, it's an F2; if you want good reliable plants at the keenest prices, go for open pollinated varieties.

And if you're an organic gardener, many like me, wont touch the F1/F2 varieties because the seeds aren't guaranteed to come true if you're a seed saver. I've just been looking at the tomatoes in the T&M catalogue and the vast majority are F1 and therefore, personally, I choose not to buy them, I'd rather let nature take its course in my garden and not go for the uniform types across the board. To me, the F1 and F2 have too much of the grade 1 and grade 2 supermarket fruit and veg about them, everything the same and uniform.

Wow 0026461, I was going to say thanks for writing out such a detailed answer, but I'm actually going to say, don't you think you could have given Thomson and Morgan the kudos for writing your post?

What I don't understand about it, is how do they know the F1 is going to take the right characteristics from the two parent plants?
For example a famous scientist was once approached by a famous beautiful actress. Marry me she said, lets have babies, with your brain and my looks, our offspring with be rich and famous. yes said the scientist, but what if they have my looks and your brains?

I'm now growing the F3 generation from Sungold. I've heard of people swapping F8 and 9 seeds from this variety which have generally settled down to a stable and pleasant (though not exactly the same) version. Interesting stuff.

Thank you for your replies.I used to grow Grenadier tomatoes (F1) which I particularly liked. They took them off the market. Last year my son found someone (on the net) who produced them so we bought them and they are now growing happily in my greenhouse. I was wondering how he managed to produce them and if I could collect the seed and have a go.Obviously not from your replies.

The producer must have the 'secret recipe' - he knows which parent plants to cross!

Kath - I've bumped 2 F1 seed posts for you to have a persuse at.

There's also a post on here about 2000 tomato varieties; perhaps you can find in there a tomato that is open pollenated that would suit your needs.

Both the other posts are worth another read.

Thanks Zazen999...I will enjoy reading them.