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Nova Scotia

if you have two unrelated pumpkin/squash plants that are showing obviouse signs of hybrid vigor. What would be the results of these being crossed?

Would this cross cancel out the hybrid vigor or possible even increase it in the next generation?

2/12/2012 9:04:34 AM

Brooklyn Corner, Nova Scotia

Good post Sean. The short answer is maybe, but not necessarily to both scenarios. The 1725 Harp is a selfed seed that retained the traits of the parents, maybe those traits were reinforced. Generally speaking, the more numerous the differences between the uniting parents — at least within certain limits — the greater on the whole is the amount of potential stimulation. The old way of thinking was same x same= weakened offspring and same x different= strong offspring. We know that it is much more complex than that.

2/12/2012 11:07:51 AM

Nova Scotia

So If I purify my hybrids by selfing once or a few times first, then intoducing them to each other, my chances are better for producing an even better hybrid? If so how, by how much do I improve my odds of proding a new hybrid by purifying first?

Or with the now large gap between the good pumpkin and squash breeds is that in itself enough genetic purity to the lines to give hybridization?

2/12/2012 1:41:09 PM

Nova Scotia

sorry for previose and any following typo's lol

2/12/2012 1:45:46 PM

Eastern Washington State

Try it and see.

The advantage of creating selfed lines then intercrossing them to get a hybrid is that the hybrid is predictable. The hybrid won't necessarily be even as good as the original vigorous starting plants. However you know what you're going to get every time.

2/13/2012 3:51:38 PM

Deer Park, WI

I do not mean to rain on the proverbial parade, but there are a few limitations in the scenario proposed.

Foremost, we as growers of the voluminous cucurbita maxima have no means to identify if a plant is exhibiting true hybrid vigor. Crossing a horse and a donkey results in a measurable effect- the mule's mix of endurance and strength can be measured against the qualities of its parentage.

Delineating the effects of potential hybrid vigor in pumpkins isnt nearly so straightforward. How could this be measured? How would you differentiate HV vs superior genetics vs perfect environmental conditions in regards to remarkable fruit growth/rate?

Unless you are a wealthy commercial entity or academic research institution with the means to perform highly controlled trials, there's absolutely no way to draw conclusions regarding the potential impact HV may or may not be having within our favorite species of veggie. (this coming from the guy who originally penned the articles on this subject years ago...)

Now, if you remove the word "hybrid" from your original statement and simply cross two plants demonstrating "vigor", I believe you are, by darwinian effect, selecting for this trait(s) and perpetuating by natural selection. Assuming there's a relation between "vigor" (this can mean a lot of things to a lot of people) and fruit weight, then this practice may be a significant contributor to the exponential growth in remarkable fruit weights this hobby has experienced over its short tenure in history.

2/13/2012 5:49:35 PM

Rhode Island

thats exactly the effect i was shooting ( hoping-lol) for when i did a 1725 sib last year. i pollinated my 1725 harp (grew to 1647 and was very thick and over chart) with rons 1725 freak (1789 late august but blew a pin hole in the rib).
im hoping for the 1647 offspring to grow somewhat fast like the freak,but with the wall thickness of the 1647.then pray that it makes it all the way.
ill let ya know come sumertime.
pap

2/13/2012 6:48:23 PM

Eastern Washington State

Yeah Joe I agree. I will reiterate that anyone capable of growing two plants at a time can make their own inbred lines and produce their own reproducible hybrid. However the key phrase in my previous post was " The hybrid won't necessarily be even as good as the original vigorous starting plants. " The commercial entities can actually measure heterosis and test combining ability of multiple inbred lines to choose the best ones.

2/13/2012 8:04:54 PM

Owensboro, Ky.

Kul beans, pap...way Kul...now I for one am wanting to know??? What is yer pick for a pollinator? 1725 again? Peace, Wayne

2/14/2012 2:22:36 AM

Rhode Island

no wayne because id be afraid of producing seeds that would be steril. which i believe will happen if you inbreed to much.

ill introduce something from outside the 1725 lines but at the same time something that ron or i will plant in 2012 thats already a proven seed.

pap

2/14/2012 1:24:37 PM

Alaska

When you cross two hybrids for the first time you get an F1 Hybrid. In order to get a true dependable hybrid to begin with you need to isolate a single parent line and grow not just one plant and then self the fruit. You have to grow thousands of plants from that isolated parent line selecting the desirable traits you are looking for. Crossing likes with likes and through that process you lock in those traits giving yourself uniformity of fruit with practically every seed you plant.
One trade off is inbreeding depression. Typically then when two highly inbreed lines are crossed with each other you get a release from that inbreeding and have improved vigor. Sometimes it very noticeable.
That's my laymen understanding of hybridizing so I'm not so sure any one in the giant pumpkin growing world has done just that. Way too much variability in AG's to be throwing around the word hybrids, IMHO.

2/14/2012 1:56:20 PM

Alaska

I personally think there are already two highly inbred lines out there ready to be crossed. Green squash with the AGs. IMHO.

2/14/2012 2:04:03 PM

Eastern Washington State

Ok lets step back a bit and define what we are discussing.
A term 'F1 hybrid' typically refers to the first generation cross between two unrelated, inbred parents. Sometimes not always, a hybrid will demonstrate 'hybrid vigor'. Hybrid vigor or more accurately 'heterosis' is a genetic advantage given by having genetic differences at one or more genetic loci, or 'genes'. You can have heterosis without having a hybrid, and you can have hybrids that don't have heterosis. So crossing unrelated individuals won't necessarily be better than selfing something good. The big payoff is when you can identify and reproduce those inbred lines that give heterosis. As mentioned earlier that takes a lot of trial and error.

2/14/2012 4:20:36 PM

Nova Scotia

great posts, thanks all.

So I don't have the space, or time to create a true hybrid, :(

but I will go for Joze theoritical Darwin outcome.

so I will merely cross 2 totally unrelated plants that both throw the same chariteristics that I desire.

which is very high vigorous fruit growth ending in, very large and heavy fruit. With no ribs, no dill rings, no internal cracks, non splitting, with nozes.

so in layman's terms big and indestructible. Which is what us one to two plant growers really needs.

Hopefully this is what I end up with, with some consistancy.

2/14/2012 4:47:38 PM

President - GPC

SO Mr T...do you have an idea of which seeds you like for this tendancy? I liked the 991 Urena... Long and doesnt seem to have deep ribs.... likes to grow BIG oNeZ too...Good Luck in your endevour

2/14/2012 4:51:02 PM

Nova Scotia

I sure do. me and a friend have both already crossed in seedlines that produce such fruit from very different genetic back grounds or as different as you can get in this sport.

But the best laid plan's still may prove unseccessful. But I feel hopeful I will get something very close to what I'm looking for. which should produce great fruit, but I hope amazing.

2/14/2012 5:04:42 PM

Alaska

Two different unrelated hybrid parent lines is what I was trying to say. Thanks for clarifying Brian.

2/14/2012 6:45:54 PM

Deer Park WA

Dani and I took last year off to build our soil so we wouldn't be wasting great seeds and lots of time. This year we will grow out the 1610 Lieber (1161 Rodonis X self) X the 823* Gadberry (834* Gadberry X Self) to see if we can get a spark between them... As far as I can tell they are really isolated.

2/15/2012 2:46:59 PM

Nottingham, UK

Steven Sperry took the 1610 Lieber and crossed it further with a 1161 Rodonis. I plan to grow the resulting 1304. I was also going to grow an 852 Myers for beautiful orange but am now wondering if I should replace the 852 with a 738 Wagler (852 Myers x self).

Then: 1304 Sperry x 738 Wagler

Sound okay?

2/22/2012 9:19:47 AM