Author Topic: Cross pollinating  (Read 4669 times)

Spireite

  • Half Acre
  • ***
  • Posts: 159
Cross pollinating
« on: August 16, 2012, 10:04:16 »
..and some more questions...

1) if I have more than 1 type of squash/pumpkin in my garden, do I have to worry about cross pollination or only if I want to save my seeds - or do people on here genuinely experiment with deliberately cross pollinating their plants?

2) What does F1 mean in the name of a seed?

3) are hybrids better or worse...and if they are hybrids will I be able to harvest my seeds for following years?

Thank you
N. Herts, just acquired first allotment in Aug 2014.

Allotments 4 All

Cross pollinating
« on: August 16, 2012, 10:04:16 »

Dandytown

  • Hectare
  • *****
  • Posts: 505
    • Pumpkins Growing Diary
Re: Cross pollinating
« Reply #1 on: August 16, 2012, 10:37:20 »
Cross pollination only affects the genetic material inside the seed of the pumpkin that has been pollinated.  It will not affect the pumpkin itself in anyway.   

If you want to save the seed to grow that exact pumpkin again then you have to make sure that you tie up a male and female flower the night before they open and it takes practice to gauge the exact day.  Tying them up will prevent pollinating insects from contaminated them with foreign pollen.  The next day you need to untie and hand pollinate yourself and re-tie the female.  If the pollination has taken it will have done so that day as the window for pollinating is very small.

Cross pollinating is practiced as a matter of routine by atlantic giant growers in an attempt to select and refine desiarable characteristics from the parent plants.  This year I grew a bon bon F1 seed which is superior in growing habits and flavour ect then the plants that were cross-pollinated to produce it.

I believe F1 means first hybrid  resulting from a simple cross pollination of plant a (female) with plant b (male=pollinator).
If after having grown your F1 seed you are happy with the produce and want to grow it again you just have to make sure you self it (i.e. pollinated the female flower on the plant with pollen from a male flower of that plant) and you will obtain the same seed time and time again.

This year my atlantic giant pumpkin will be open pollinated and therefore I would not offer these up to anyone for the reason that we do not know what genetic material was used to pollinate the female flower.  As a result the seed from it could grow duds.



galina

  • Hectare
  • *****
  • Posts: 4,779
  • Northants/Beds border
Re: Cross pollinating
« Reply #2 on: August 16, 2012, 12:03:52 »
Yes agree with Dandytown - fruit and seedcoat is maternal genetic material.  This means the fruit will always be whatever the seed variety was (provided it was true breeding and not crossed).  This means that you cannot see whether a squash has been crossed with pollen from another variety of the same species.  Pollen is the paternal contribution.  Only the germ inside the seed coat distinguishes a fruit thas has been crossed from one that hasn't been crossed.  

You can't see crosses with beans either.  Bean crosses are of course very much rarer than squash crosses, but the beans inside the crossed pod look exactly like the mother variety.  

You can however see crosses with sweetcorn.  But the same rule applies - it just so happens that sweetcorn has see-through seedcoats and you can see the colour of the germ inside.   Some people in the USA who want to make sure they do not get GM cross pollinated sweet corn, choose blue varieties, as all GM corn is yellow.  If they see yellow kernels, they remove them, the rest of the cob is then GM free.

F1 is the 'first filial generation' - 'filial' means child generation.  F1s are often very uniform and display the dominant features of both parents.  A tall pea for example that has been crossed with a dwarf pea (peas almost never cross on their own in nature, but they are fairly easy to cross by experimenters) will be tall in the F1 generation, because only the dominant features are coming to the fore.  F1s also show something called hybrid vigour.  They often are bigger plants with bigger fruit and more uniform.  This is why F1 seeds are more expensive to buy and often produce bigger fruit on more vigorous plants.

If you cross the F1 generation with itself (ie take a female flower of an F1 squash and pollinate this with a male flower from the same squash and prevent any other stray pollen getting into that female flower), then the seeds produced will be the F2 generation, second child generation (or grandchildren generation).  If you grow these seeds, something pretty amazing happens.  Whereas in the F1 generation only the dominant features came to the fore, in the next generation you get dominant and recessive genes expressing themselves and the result is a great diversity of different plants - big, little, good ones, naff ones - the whole manifestation of what the cross can produce.  I grew F2 lettuces this year from a chance lettuce cross and each plant was different.  Now I can choose what lines I want to carry on with for a brand new lettuce variety of my own making.   I was lucky to get two plants that were really good and late to bolt with it.  :)  

If you cross one female squash flower with a male of the same variety but on a different plant, the result is true-breeding offspring,.  because both parents are the same variety.  If you cross a female flower with a male flower of the same variety on the same plant, the result is also true-breeding.  But it is better for plant vigour if two different plants are involved for some vegetable types.

Yes you can save seeds from hybrids, but as I wrote above what you will get in the F2 generation is a big gamble.  You could strike it lucky and find a really good F2, which could be the start of a new variety, but most of your plants will only be so-so or even inferior.  My lettuce bed was only about 4 square yards, no problem with a few naff plants, but if you have limited space and need your squashes to perform, this may not be a gamble you want to risk.  If you start off with an open pollinated squash variety and let it do its own thing, you might get the same again, if female and male happen to be the same variety, or a cross, depending on the way the visiting bees travelled.  You can get away with growing this potential cross next year, because it will be a plant with hybrid vigour, even though the exact resulting type may be a mystery.  It will still be somewhat similar to the mother variety, because it will have the dominant features of the mother variety (and the father variety).  In the case of my lettuce I got the leaf shape and frilly edges of the father variety with the red blush of the mother variety in the F1 generation and it was a big lettuce with lots of greens for the table before it started bolting.

Sorry this has been such a large post, but I don't know how to answer your questions briefly .  Hope this helps.  
« Last Edit: August 16, 2012, 12:10:36 by galina »

Spireite

  • Half Acre
  • ***
  • Posts: 159
Re: Cross pollinating
« Reply #3 on: August 16, 2012, 12:16:00 »
Wow thanks DTown and Galina...lots of genetics, thank you....just trying to recall A level biology....1 :16 chance of certain characteristics...  ::)
So...When talking about F2 plants and their characteristics... the plant.. or the fruit?  As in a F1 plant, some of it's fruits will be self pollinated, and some may be pollen from a turk turban from across the garden??
I just want to be sure before attempting to grow more than 1 type of squash/pumpkin in my garden next year.  I keep reading about types I want to try...too much choice.. ;D
N. Herts, just acquired first allotment in Aug 2014.

galina

  • Hectare
  • *****
  • Posts: 4,779
  • Northants/Beds border
Re: Cross pollinating
« Reply #4 on: August 16, 2012, 12:41:28 »
Wow thanks DTown and Galina...lots of genetics, thank you....just trying to recall A level biology....1 :16 chance of certain characteristics...  ::)
So...When talking about F2 plants and their characteristics... the plant.. or the fruit?  As in a F1 plant, some of it's fruits will be self pollinated, and some may be pollen from a turk turban from across the garden??
I just want to be sure before attempting to grow more than 1 type of squash/pumpkin in my garden next year.  I keep reading about types I want to try...too much choice.. ;D

Not quite - the Turk's Turban across the garden will potentially cross pollinate the Bon Bon, because both are of the species cucurbita maxima, but the Crown Prince down the road will also need to be considered, because bees have a large area, certainly half a mile, but can be more than two miles.  They tend to concentrate on one type of plant at a time, so will visit all the squashes in the vicinity and one flower might well be visited by half a dozen several insects.  You could end up with a few seeds that were pollinated with the same variety and others that are crosses with several others of the same species.  

All the F1 seeds in a commercial seed packet have been produced to be entirely uniform - unlike the seeds in your garden if you let the bees get on with it.

There are different species in squashes.  The cucurbita maxima Turk's Turban will not pollinate the courgettes or the acorn squashes in your garden, because those are cucurbita pepo.  And neither will it cross with butternuts, which are cucurbita moschata.

You can grow as many types as you want.  The F1s you buy in seed packets and the open pollinated ones you buy in seed packets will all give you predictable fruit whoever was the pollen daddy  :) If you buy Turks Turban, F1 Bon Bon, Uchiki Kuri and Crown Prince just for growing, they will all produce the fruit you expect.  If you let them do their own thing and they cross, you will get some that are not crossed, some that are F1s and all F2s from the Bon Bons.  But you cannot tell by looking at the seeds what will happen if you grow from these saved seeds. 

Talking about F2 characteristics, I meant both the plant and the fruit.  You could get a huge rambling squash with tiny fruits or a short vined squash with bigger fruit.  Or a huge rambling squash with huge fruit and vice versa.  F2s are diverse in a good way or a bad way  ;D
« Last Edit: August 16, 2012, 12:46:53 by galina »

Dandytown

  • Hectare
  • *****
  • Posts: 505
    • Pumpkins Growing Diary
Re: Cross pollinating
« Reply #5 on: August 16, 2012, 16:06:35 »
Thanks Galina for responding in a more legible fashion than I  :)




Robert_Brenchley

  • Hectare
  • *****
  • Posts: 15,593
    • My blog
Re: Cross pollinating
« Reply #6 on: August 22, 2012, 17:24:55 »
An F1 is produced by crossing two varieties. So, for instance, they plant two corn varieties together - neither variety is, of course, available to buy. One gets all the plants beheaded, so there are no male flowers, and all the seeds are pollinated by the other. Or they might breed a male sterile variety which produces no pollen. So all the seeds are a cross. Both varieties are severely inbred, but the offspring is vigorous, and as the plants are almost genetically identical, they all behave in exactly the same way, which suits the farmer. If you save seed, it won't come exactly true, so the seed companies propagate the myht that you 'can't' save seed from F1's, and gain a captive market.

In fact, you can save seed, and develop your own, very similar, variety.

Spireite

  • Half Acre
  • ***
  • Posts: 159
Re: Cross pollinating
« Reply #7 on: January 05, 2013, 22:52:09 »
So I think I have a short list of pumpkin/squashes to grow this year, 3 of which I think are cuc.pepo and one which I think is cuc.maxima...Am I right in thinking that the 3 pepos will potentially be promiscuous and the maxima is safe from cross pollinating?
N. Herts, just acquired first allotment in Aug 2014.

galina

  • Hectare
  • *****
  • Posts: 4,779
  • Northants/Beds border
Re: Cross pollinating
« Reply #8 on: January 05, 2013, 23:56:16 »
So I think I have a short list of pumpkin/squashes to grow this year, 3 of which I think are cuc.pepo and one which I think is cuc.maxima...Am I right in thinking that the 3 pepos will potentially be promiscuous and the maxima is safe from cross pollinating?

In principle yes.  However, it also depends on what your neighbours around you grow.  Bees can travel from one maxima to another a quarter mile away if you are unlucky. 

But if the bee transfers pollen from one of your pepos to the maxima it won't do any pollinating.  Only maxima pollen will achieve that.

If you just want fruit to eat, don't worry you will get the three different varieties you have sown seed for, if you want to save seeds, it is best to isolate and handpollinate because of the long distances bees can travel and pollinate.

Spireite

  • Half Acre
  • ***
  • Posts: 159
Re: Cross pollinating
« Reply #9 on: January 06, 2013, 12:42:49 »
Well I'm mainly growing for the fruit, but I thought I'd take a chance with last year's jack o  lantern seeds I have which is a pepo, which I only intend to grow big enough to carve and not eat..and I don't think that my neighbours grow squashes, but there's no way to be sure of that....so it's a wait and see....surely it will be more of an issue with the squashes I intend to eat, and if I save their seeds for next year  Magical mystery tour  :happy7:
N. Herts, just acquired first allotment in Aug 2014.

galina

  • Hectare
  • *****
  • Posts: 4,779
  • Northants/Beds border
Re: Cross pollinating
« Reply #10 on: January 06, 2013, 23:49:20 »
Well I'm mainly growing for the fruit, but I thought I'd take a chance with last year's jack o  lantern seeds I have which is a pepo, which I only intend to grow big enough to carve and not eat..and I don't think that my neighbours grow squashes, but there's no way to be sure of that....so it's a wait and see....surely it will be more of an issue with the squashes I intend to eat, and if I save their seeds for next year  Magical mystery tour  :happy7:

I love that magical mystery tour too :wave:  and had some nice crossed maxima.  First year usually good, second year more of a gamble.

Dandytown

  • Hectare
  • *****
  • Posts: 505
    • Pumpkins Growing Diary
Re: Cross pollinating
« Reply #11 on: September 13, 2013, 19:34:27 »
An old post revisited.

An observation I made this year was of the bumble bees frantically jumping from flower to flower on my atlantic giants.  Some of the bees were covered in pollen almost if someone had licked them and dunked them in a pot of yellow powder. 

They were so covered in pollen that flight must have been taxing.

Served to remind me about the importance to tie your flowers closed (both male and female) the night before pollinating if you do not want an open pollination and plan to save and grow the seed.