From

Location

Message

Date Posted

Brooklyn Corner, Nova Scotia

I was looking at some posts on this subject recently and wondered if there was any merit to the validity of crossing proven AG stock with established squash lines. Ben Hebb did this many times, notably his 1056*- 836* Neily x 1068 Wallace. No idea if this seed was ever planted, let alone the conclusions. To me, they are all AG's. But Ben Hebb knows a lot more than I do.
Pap recently proposed a squash/ ag graft. The rationale being an introduced vigor brought on by combining the two. Way above my pay grade, ut bwouldn't a proven AG ( 1068 ) x a pure squash line ( 836 ) reach the same conclusions?

12/15/2014 9:34:19 PM

Northern California Foothills

I think they are too genetically similar for their to be much hybrid vigor but there's no harm in trying it.

12/15/2014 10:21:24 PM

Springfield, Missouri

Hey Andy, hope I'm able to help. The terms that we really need to look at when discussing hybrid vigor are heterosis, inbreeding depression, and genetic load.

Hybrid vigor, in plant breeding, is used for quality control more than anything else, and is what occurs when you cross two dissimilar inbreed lines together. Corn is the prime example, modern farmers need a uniform crop so that it is easier to harvest, and process. In order to have a uniform crop every plant needs to be very genetically similar (clones).

Each individual, in a highly inbreed population is essentially a clone, but the extreme level of homozygosity causes these plants to be severely stunted with low yields. If two completely homozygous plants are crossed then heterosis(vigor) is re-established, and every offspring will be nearly identical.

12/15/2014 11:01:05 PM

Springfield, Missouri

In the context of a home gardener think F1 Hybrids in your seed catalogs. We buy the F1 hybrids because we know there will be uniformity, and that they are productive.

Apples and grapes exhibit a different kind of hybrid vigor. These plants rely on wind pollination, and thus the chances of self pollination are low. High levels of cross pollination prevent the purging of lethal recessive mutations in a population. The amount of recessive lethal mutations in a population is refereed to as genetic load. Species such as apples must be constantly out-crossed to maintain vigor.

12/15/2014 11:20:26 PM

Springfield, Missouri

For the most part our pumpkins have a high level of heterosis as is, this is why the 1495 Stelts for example has produced kins anywhere from -5 to +25 to chart with green, mottled, and orange skin.

So getting to the root of your question no there won't be any "hybrid vigor", because the parents heterosis would be about the same as the offspring. It is beneficial to cross the two populations? I believe so.

Each population has traits of interest, and each is showing signs of genetic load. Lethal mutations in the AG population include sterile male and seedless fruit. Possible lethal mutations in squash are difficulty setting fruit. Crossing the two populations would hide lethal mutations by diluting them in the new gene pool.

12/15/2014 11:39:48 PM

Corryton, TN

Been tinkering with these crosses for a few years and I have not seen the hybrid vigor show up as a boost in size in the F1 offspring like you would expect in livestock. Logan explained it well.
What a few of us are doing is trying to capture the green gene from the squash in F2 or squash x F1 backcrosses while stacking the newer pumpkin genes to increase the size of the squash at a much faster pace. The F2 cross is what produced the current world record squash for Scott Holub.
With the current squash color rules we have to look for seeds from large darker pumpkins to ad to the squash so as to stay away from the "diluter" genes that produce the whiter or washed out colors. Same problem that the HD orange growers have.

12/16/2014 6:42:10 AM

Central Illinois

I didnt think grafting made hybrid vigor, it could only be done through pollen exchange ?

12/16/2014 8:25:24 AM

Corryton, TN

We're not referring to grafting here. We're referring to crossing green AG's (squash) to orange AG's (pumpkins).

12/16/2014 12:50:25 PM

Eurasia

Len Stellpflug is one of the best squash and pumpkin growers ever. He simply enlarged his competition squash fruits by crocheting in AG-genetics. You can do this play for a very long time but not alienate the squash traits.
I have done an experiment with Turk´s Turban for some years now. First I selected only green and then I made stretto lines of them. This inbred dark green fruits with light green to whitish-grey bun were pollinated by an inbred AG to get a standard variety of a larger only green turban in 2014. Xenia (on the base of pollen) made 14" wide flat fruits, while the mother was a TT mini with 4" fruits only. In 2015 this 14ers will be selected. Only the flat fruits are of great interest.
The few biggest globe fruits are not heavy (thinner wall) and can be trashed.
The flat oval fruits will show different colors but as F1 nearly the same size.
Only the flat dark green ones are chosen for 2016.
Grey fruits are trashed too.
There will also be a few smaller mottled fruits...trashed.
So I can hope to grow one of ten or one of twenty fruits
in 2016 and pollinate their seed´s plants with an inbred line of AGs (stretto line) again.
It´s a long way to make a giant from a 4" mini fruit.

12/16/2014 12:50:31 PM

Eurasia

I can also make green pumpkins, as I have stated here three years ago. Nobody wanted to here that, but it is of interest to make large pumpkins green instead of going the long way. These pumpkins turn only a little orange in winter, but they are green for squash competitions.
You simply have to soak the seed in a juice of Salix sachalinensis 'Sekka', cured with a little Fe-III-sulfate.
The plant will develop broader vines then, like the dragon willow has broader branches.
The fruit grows 15 to 30 % larger and more around 50 % higher in weight, when I use Cucurbita pepo.
I have not used this practice for C. maxima yet, but when the sekka-virus does it so excellently well in the halloween groop of pumpkins, it might work for all other groops too.
The false squash fruits develop seed, but the next generation is barren, like the dragon willow always is infertile and only multiplied by cuttings.
My C. pepo 'Little Paintball' fruits were so dark green, that you might say black. It would be very funny, if a 2000#er would come as a black monster to the weighing.

12/16/2014 2:34:28 PM

Deer Park, WI

To clear the air, hybrid vigor cannot be induced by grafting. HV is exclusively a process that occurs when sperm meets egg.

I pontificated on the subject of HV in AG's much in my earlier years of growing, and quickly realized that without a systematic way of measuring for this effect, every discussion on the matter was purely conjecture.

Until well designed and controlled experiments can be performed, its role in competitive fruit production will remain a mystery.

Tom Beachy, Nic Welty, I'm passing the mic to you now.................

12/16/2014 5:06:00 PM

Pocatello (cliffwarren@yahoo.com)

Hey Joze, good to hear from you.

Let's say you grafted an AG onto a Squash root. What are you growing? An AG, and that's all. You would pass no genetic information of the squash into those seeds (assuming that you pollinate the fruit with an AG, but that is another matter). The only thing that would happen here is that the AG plant would be "nourished" by a Squash root. This may or may not introduce "vigor", but it is not hybrid vigor.

12/16/2014 5:20:09 PM

Eurasia

There are so many ways, we use hybridisation. We do not only want a F1 for homogenisation of traits like size or flavour, nor does that work end-to-end.
But the discussion about grafting is 100 years old! Nobody wanted to accept the term hybrid vigor for grafting, when Mitschurin / Michurin made his new (mainly apple) grafting varieties with more then one different slips on one sleeper. The sleeper should be influenced positively by more different slips, and then the apples on the old wood would be better with a hybrid vigor and real seed.
Lenin accepted that hokum and superelevated Michurin to the god/pope of biology, Stalin made a doctrine for the sowjet´s biology with that sketchy stuff and the botanist Lyssenko perverted it after WW II as the great dictator of biology, who repressed Wawilow, who worked with Michurin decades before.
Since I have seen the grafting experiments with AGs done by Don Young here at pb, I can´t take him serious.
As a breeder I hate grafting.
Everything should be done with the whole plant.
For sure, there are influences of slips to the sleeper, but I do not want to waste my time with methods, that are not gainful for squash and pumpkin.
For melons or apples grafting is of interest, but Mitchurin told the world bullshit about hybrid vigor through on grafted apple-trees.
Is graftijg realy needed for melons?
I always find ways to breed whole plants...I have bred melons on pumpkins and we make potato-leave-tomatoes from real seed now and not only via grafting, like Michurin did.
I play with all groups of cucurbits like on a musical instrument.
So why should I make slips on the keys of my piano? Grafting is stupid...

12/16/2014 6:35:45 PM

Springfield, Missouri

I agree with Dave our squash are just green AGs, so there is no sense in grafting the two. I recommend watching lecture 28.

https://www.youtube.com/playlist?list=PLs7Y2nGwfz4FL4ZJgONHsl1qp-AZPr3tJ

I have no experience with grafting cucurbits, but I have done so with grapes. I was able to attend the ASEV International Conference this year, and grafting was discussed in detail. Root stocks need to have properties that the original roots do not, which will allow the plant to grow better in certain areas/situations.

It is a common practice to use different species in the same genus as root stocks. Vitis vinirfera (wine grapes) evolved and adapted to Europe's environment. Australian growers use Vitis rupestris, a species that comes from/ is adapted to SW USA. This rootstock has different root angles which allow the plant to be more drought tolerant.

12/16/2014 7:32:47 PM

Sourthern Utah

i have not had any success as far as grafting Ag's,, the last 2 years that i have attempted,, but i will continue to put large kin genes into the squash plants i grow,, i do have several very nice canditates to play with again,, this next season,, may the giant pumpkin not leave his mark on the greenie's,, lol,, just me

12/16/2014 7:44:17 PM

Springfield, Missouri

I have several other people on board to help me with my interspecific breeding project. These growers might be able to help me elaborate on the positive characteristics , of other species, that could be of use in the future.

Pap if you would like to test different rootstocks I will send you some of my seeds which might be more drought tolerance or have crown rot resistance. The crowns don't get nearly as big, but the root system is just as extensive.

12/16/2014 7:44:51 PM

Brooklyn Corner, Nova Scotia

Wow great answer, thanks Logan. The idea popped into my head after reading the posts on older seeds and Dick's post on grafting a pumpkin scion to squash root stock. Going through some older seeds I came across a 568 Andrews 99- 738* Stellpflug x 1092 Burke. The 1092, as you know, is 935 Lloyd x self. The result of 3 generations of selfed/ sibbed 687 Lloyd seeds and arguably the mother of giant pumpkins as we know them today. But I digress, the Stellpflug/ Burke cross in itself seems to me to have loads of potential. Crossing the 568 Andrews with, let's say a 1730 Werner for example, is Nirvana, at least on paper. Thanks again for the reply.

12/16/2014 9:34:42 PM

Farming- a bunch of catastrophies that result in a lifestyle

I'd like to ask a question, but please bear in mind I know very little about grafting. My dad has all kinds of fruit trees and they are all grafted onto something called root stock. If a pear is grafted on an Apple root stock it still grows pears. Does it work the same with cucurbits? Like: grafting an AG on a yellow squash is still just an AG, all the yellow squash root does is provide nutrients? Do I have that right?

12/17/2014 6:31:00 AM

Menomonie, WI (mail@gr8pumpkin.net)

LB you have it close. They say the rootstock can also help with disease and virus resistance. This then makes a stronger plant

12/17/2014 7:29:36 AM

Little-TON - Colorado

Hmmm, Grafted tomatoes....

12/17/2014 9:57:27 AM

Bethlehem CT

The rootstock can also be used to dictate plant size. Dwarf fruit trees are grafted onto a less vigorous root stock and therefore the tree is smaller. Often times the roots are so small on dwarf fruit trees that the trees require staking so that the trees don't uproot themselves when covered with fruit.

12/17/2014 2:52:24 PM

Deer Park, WI

The 568 Andrews was indeed a revolutionary seed. It grew my first competitive AG back in 2001.

Cliff...good to see you too. we should do this more often. :)

grafting- the one practical application i see for grafting in AG's is matching root systems with desirable qualities to above ground vegetative systems with desirable qualities.

Indeed, a root system with known disease resistance (here in the upper midwest, we found a hopkins seed that did not succumb to pythium the way other seeds did, suggesting some degree of resistance) coupled with the fruit producing power of a 2009 Wallace or 1725 Harp could create a useful combination.

The limitation, of course, is you are NOT breeding the root strength into the plant. genetic information from the root stock cannot be passed into the new seed stock. This is why grafting is kinda lame and really only has practical utility for perennial plants.

12/17/2014 5:26:48 PM

Brooklyn Corner, Nova Scotia

Ok Joze, lay it on me. The root stock may be disease resistant so I guess pathogens are shown the way out at first instance, protecting the plant. The root stock grafted to the rest of the plant is only capable of sending nutrients and water, not genetic information. That's good right? LG stock grafted to watermelon, producing two world records, not watermelon/ long gourd mutations.

Great discussion by the way. I expect to be put in my place very much like Scott Holub ( bathabitat ) did me when I questioned mother weight relating to offspring potential
( weight ).

12/17/2014 9:41:04 PM

Eurasia

http://forums.gardenweb.com/forums/load/gourds/msg121508205082.html?25968

12/18/2014 4:53:21 PM

Eurasia

At this link before, you can see a huge difference in xenia between green and orange Turk's Turban fruits, when pollinated by AGs. Next year I will see, if there is such a huge difference in real hybrid vigor too.

12/18/2014 5:01:03 PM

Ohio

For years and as recently as 2010 "giant pumpkins" were entered under "class 6 squash by weight" at my local county fair. The purest in me always appreciated that the county horticultural and agricultural fair had it right. For the past few years the category has been changed to "class 6 pumpkins by weight" and it seems so wrong.

12/18/2014 7:33:01 PM

That State Up North

Hybrid vigor is such a complicated phenomena it can't be completely explained easily.
I have seen some cases of hybrid vigor in giant pumpkins. This doesn't always happen crossing unrelated inbred lines, but in some cases a hybrid population can surpass both parent populations for fruit weight mean.
That said I don't see this as the core to improving giant pumpkin size via breading. Selection of the best traits to result in bigger fruit through fine tuning the characteristics that lead to enormous fruit.

Grafting - yes maybe there is a better rootstock strain of giant c. maxima for some giant pumpkins. Some gains in disease resistance and or stump size. The real gains can be seen grafting weaker species to these remarkable c. maxima lines in order to improve their performance.
Now discussion of rootstock impacts to phenotypic plasticity could be a great topic.

Yes class 6 should be squash by weight

12/18/2014 10:16:54 PM