F1

[dave45]

I didn't do O-level biology but ISTR that an F1 Hybrid plant is made from selected different parents and its seeds will not breed true/the same.

So I have some F1 Applause (I think) sweetcorn - what WILL happen if I save the seed and grow it next year? Anybody tried it?

[Odsox]

No, not sterile at all, in fact they will be F2 hybrids which could be similar to their parents, or nothing like them, or even a one in a million chance of something better.
There is something that I have wondered, if you take a seed from one of these new parthenogenic courgettes, would that grow and if there was no chance of cross pollination, would that still be F1 ?

[MKG]

No, not sterile at all, in fact they will be F2 hybrids which could be similar to their parents, or nothing like them, or even a one in a million chance of something better.
There is something that I have wondered, if you take a seed from one of these new parthenogenic courgettes, would that grow and if there was no chance of cross pollination, would that still be F1 ?

Important things like this occupy my mind, too, when I'm lying in bed.

The answer's no - an F1 is a first-generation offspring. A parthenogenetic plant would be producing clones, certainly, but although they would be genetically identical, they could hardly be described as first-generation. It's the physical act of crossing the two parent plants which defines an F1. Now you can move on to the relationship between equatorial bullfrogs and the efficacy of lawn-mower blades.

Mike

[Green Aura]

Mike there are far more interesting, enjoyable and important things to do in bed - reading and sleeping spring to mind

The F1 seed is very unlikely to come true, it usually reverts to one of the parents, or very rarely - like one of the men who think in bed too much says - some different entity altogether - although presumably still sweetcorn

Give it a try, but don't rely on it for your main harvest. If you get something wonderful and can replicate it again the year after you can call it dave45 sweetcorn

[Odsox]

The answer's no - an F1 is a first-generation offspring. A parthenogenetic plant would be producing clones, certainly, but although they would be genetically identical, they could hardly be described as first-generation. It's the physical act of crossing the two parent plants which defines an F1

Thank you Mike, and I ought to have explained myself more fully.
I realise that it couldn't be an F1 because there would be no hybridisation, what I should have said was "identical to F1" instead.
You put it more succinctly with "clone" which would of course be similar to taking a cutting.
I will have to try that next year and see if the seed is indeed viable.

I think though if you tried to cross a bullfrog with a lawn mower blade, the outcome would be a great deal more predictable.

[grahamhobbs]

Surely there is a lot of mysticism built up by the seed companies around F1. Sheep farmers often cross one breed with another, not because they are particulary looking to blend the charateristics of the two, but because you get a certain vigour in the offspring, but you start with two good breeds to start with. Isn't it the same with F1 seeds, you take 2 good varieties and cross them to get that extra vigour. If you then use the seeds from the F!, assuming you haven't allowed it to cross-pollinate with another variety, you can only get one or other of the 2 good parent varieties or their cross again. It is going to be a sweetcorn and a reasonably good one but perhaps without that extra vigour. Given the money they charge for a miserly number of sweetcorn seeds I think it should be a reasonable bet.
A further thought is, even if it reverts to its two parents and you plant them together, then they might naturally pollinate each other, so you will end up with a higher proportion of F1's again - keep going and won't you have your own F1 variety?

[Millymollymandy]

Sounds like a jolly good experiment for someone to try next year and report back on!

[dave45]

well I shall certainly give it a go.... but there is a thought at the back of my mind...

why are most/all sweetcorn seeds F1s? is it because they CAN'T breed true?

ISTR reading an article years ago (Scientific American?) about maize/sweetcorn, and I think the pictures of the parents were very unlike the resulting offspring... the aztecs started it. maybe I'll end up with 3" red cobs or smth.

Still nothing like first-hand experimental knowledge eh?

And yes the price of seeds is an utter ripoff (unless they take a huge amount of care to produce - I'm guessing hand-fertilising each plant)... just look at a 3-acre field of maize and figure out the cost of seeds at retail prices...

[MKG]

Having attempted sweetcorn only once (and it was such a long time ago that I think it wasn't a hybrid at all), I'm under the impression that most seeds sold in the UK are F1 because we don't have a long-enough season for non-hybrid ones to ripen properly. Breeding for a shorter season AND fat cobs means F1s, I'm afraid.

On the other hand, my aging memory may be totally at fault on this one. No doubt we'll soon find out.

Mike

[Green Aura]

Real Seeds sell a none F1 type that you can safely collect seed from - can't remember the variety.

I'm sure I must be due some commission from them

[dave45]

well ISTR from O-level geography (or smth) 40 years ago that maize/sweetcorn needed a minimum of XXX good sunshine days to be viable. And Lancashire therefore aint suitable...

yet it grows just fine here in low sunshine hours... maybe the F1 plant breeders have moved the goalposts since then.

[KathyLauren]

Sheep farmers often cross one breed with another, not because they are particulary looking to blend the charateristics of the two, but because you get a certain vigour in the offspring, but you start with two good breeds to start with. Isn't it the same with F1 seeds, you take 2 good varieties and cross them to get that extra vigour.

Hybridization is different from cross-breeding. Cross-breeding is when you mate two different varieties of the same species, like a poodle and a labrador retriever. Hybridization is when you mate two different species, like a dog and a fox.

Because hybrids are reproductive dead-ends, the only way to reliably propagate the resulting characteristics is by cloning.

[Peggy Sue]

Real Seeds sell a none F1 type that you can safely collect seed from - can't remember the variety.

I'm sure I must be due some commission from them

Yep I grew them this year and have been eating them for a month, they are bi-colour (at least some are ) and when I can tell exactly the time they are ripe they are really sweet- but I normally get i wrong and end up with something woody coz I waited too long
I'm planning on seedsaving, I just hope they haven't crossed with anything undesirable on other allotments

[grahamhobbs]

Keith thanks for your post, it spurred me to to investigate this further, this is the clearest explanation I could find, it is worth struggling through it. If you can't manage it, the last couple of sentences sum it up.

[0004]Maize is bred through techniques that take advantage of the plant's method of pollination. A plant is self-pollinated if pollen from one flower is transferred to the same or another flower of the same plant. A plant is cross-pollinated if the pollen comes from a flower on a different plant. Plants that have been self-pollinated and selected for type for many generations become homozygous at almost all gene loci and produce a uniform population of true breeding progeny. A cross between two different homozygous lines produces a uniform population of hybrid plants that may be heterozygous for many gene loci. A cross of two plants each heterozygous at a number of gene loci will produce a population of hybrid plants that differ genetically and will not be uniform.

[0005]Maize can be bred by both self-pollination and cross-pollination techniques. Maize has separate male and female flowers on the same plant, located on the tassel and the ear, respectively. Natural pollination occurs in maize when wind blows pollen from the tassels to the silks that protrude from the tops of the ears.

[0006]A reliable method of controlling male fertility in plants offers the opportunity for improved plant breeding. This is especially true for development of maize hybrids, which relies upon some sort of male sterility system. There are several options for controlling male fertility available to breeders, such as: manual or mechanical emasculation (or detasseling), cytoplasmic male sterility, genetic male sterility, gametocides and the like.

[0007]Hybrid maize seed is typically produced by a male sterility system incorporating manual or mechanical detasseling. Alternate strips of two maize inbreds are planted in a field, and the pollen-bearing tassels are removed from one of the inbreds (female). Providing that there is sufficient isolation from sources of foreign maize pollen, the ears of the detasseled inbred will be fertilized only from the other inbred (male), and the resulting seed is therefore hybrid and will form hybrid plants.

[0008]The laborious, and occasionally unreliable, detasseling process can be avoided by using cytoplasmic male-sterile (CMS) inbreds. Plants of a CMS inbred are male sterile as a result of factors resulting from the cytoplasmic, as opposed to the nuclear, genome. Thus, this characteristic is inherited exclusively through the female parent in maize plants, since only the female provides cytoplasm to the fertilized seed. CMS plants are fertilized with pollen from another inbred that is not male-sterile. Pollen from the second inbred may or may not contribute genes that make the hybrid plants male-fertile. Seed from detasseled fertile maize and CMS produced seed of the same hybrid can be blended to insure that adequate pollen loads are available for fertilization when the hybrid plants are grown.

[0009]There are several methods of conferring genetic male sterility available, such as multiple mutant genes at separate locations within the genome that confer male sterility, as disclosed in U.S. Pat. Nos. 4,654,465 and 4,727,219 to Brar et al. and chromosomal translocations as described by Patterson in U.S. Pat. Nos. 3,861,709 and 3,710,511. These and all patents referred to are incorporated by reference.

[0010]There are many other methods of conferring genetic male sterility in the art, each with its own benefits and drawbacks. These methods use a variety of approaches such as delivering into the plant a gene encoding a cytotoxic substance associated with a male tissue specific promoter or an antisense system in which a gene critical to fertility is identified and an antisense to that gene is inserted in the plant (see: Fabinjanski, et al. EPO 89/3010153.8 publication no. 329,308 and PCT application PCT/CA90/00037 published as WO 90/08828).

[0011]Another system useful in controlling male sterility makes use of gametocides. Gametocides are not a genetic system, but rather a topical application of chemicals. These chemicals affect cells that are critical to male fertility. The application of these chemicals affects fertility in the plants only for the growing season in which the gametocide is applied (see Carlson, Glenn R., U.S. Pat. No. 4,936,904). Application of the gametocide, timing of the application and genotype specificity often limit the usefulness of the approach.

[0012]The use of male sterile inbreds is but one factor in the production of maize hybrids. The development of maize hybrids requires, in general, the development of homozygous inbred lines, the crossing of these lines, and the evaluation of the crosses. Pedigree breeding and recurrent selection breeding methods are used to develop inbred lines from breeding populations. Breeding programs combine the genetic backgrounds from two or more inbred lines or various other germplasm sources into breeding pools from which new inbred lines are developed by selfing and selection of desired phenotypes. The new inbreds are crossed with other inbred lines and the hybrids from these crosses are evaluated to determine which of those have commercial potential. Plant breeding and hybrid development are expensive and time consuming processes.

[0013]Pedigree breeding starts with the crossing of two genotypes, each of which may have one or more desirable characteristics that is lacking in the other or which complements the other. If the two original parents do not provide all the desired characteristics, other sources can be included in the breeding population. In the pedigree method, superior plants are selfed and selected in successive generations. In the succeeding generations the heterozygous condition gives way to homogeneous lines as a result of self-pollination and selection. Typically in the pedigree method of breeding five or more generations of selfing and selection is practiced: F1 to F2; F3 to F4; F4 to F5, etc. Recurrent selection breeding can be used to improve populations of either self or cross-pollinating crops. Recurrent selection can be used to transfer a specific desirable trait from one inbred or source to an inbred that lacks the trait. This can be accomplished, for example, by first a superior inbred (recurrent parent) to a donor inbred (non-recurrent parent), that carries the appropriate gene(s) for the trait in question. The progeny of this cross is then mated back to the superior recurrent parent followed by selection in the resultant progeny for the desired trait to be transferred from the non-recurrent parent. After five or more backcross generations with selection for the desired trait, the progeny will be homozygous for loci controlling the characteristic being transferred, but will be like the superior parent for essentially all other genes. The last backcross generation is then selfed to give pure breeding progeny for the gene(s) being transferred. A hybrid developed from inbreds containing the transferred gene(s) is essentially the same as a hybrid developed from the same inbreds without the transferred genes, except for the difference made by the transferred gene. As the varieties developed using recurrent selection breeding contain almost all of the characteristics of the recurrent parent, selecting a superior recurrent parent is desirable.

[0014]A single cross maize hybrid results from the cross of two inbred lines, each of which has a genotype that complements the genotype of the other. The hybrid progeny of the first generation is designated F1. In the development of commercial hybrids only the F1 hybrid plants are sought. Preferred F1 hybrids are more vigorous than their inbred parents. This hybrid vigor, or heterosis, can be manifested in many polygenic traits, including increased vegetative growth and increased yield.

[0015]The development of a maize hybrid involves three steps: (1) the selection of plants from various germplasm pools for initial breeding crosses; (2) the selfing of the selected plants from the breeding crosses for several generations to produce a series of inbred lines, which, although different from each other, breed true and are highly uniform; and (3) crossing the selected inbred lines with different inbred lines to produce the hybrid progeny (F1). During the inbreeding process in maize, the vigor of the lines decreases. Vigor is restored when two different inbred lines are crossed to produce the hybrid progeny (F1). An important consequence of the homozygosity and homogeneity of the inbred lines is that the hybrid between a defined pair of inbreds will always have the same genotype. Once the inbreds that give a superior hybrid have been identified, the hybrid seed can be reproduced indefinitely as long as the homogeneity of the inbred parents is maintained.

[0016]A single cross hybrid is produced when two inbred lines are crossed to produce the F1 progeny. A double cross hybrid is produced from four inbred lines crossed in pairs (A×B and C×D) and then the two F1 hybrids are crossed again (A×B)×(C×D). Much of the hybrid vigor exhibited by F1 hybrids is lost in the next generation (F2). Consequently, seed from hybrids is not used for planting stock.

Read more: http://www.faqs.org/patents/app/2009001 ... z0SUlDEXPP

[Peggy Sue]

Well I was inwardly digesting quite well til para 13 when I saw redcurrent instead of recurrent- was more intersting that way!