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Tomato Hybridization Questions (good ones)

Posted by High_Plains_Drifter z9 sun15 CA (My Page) on
Sun, Jun 12, 05 at 2:44

First question: which is dominant, determinate or indeterminate growth? Maybe neither? I've heard of semi-determinate growth, so maybe if you hybridize a determinate and indeterminate you'll get a semi-determinate F1. What's the deal?

Second question: if I emasculate the pollen receiver after the flower has just begun to open, can I still add pollen from another plant and get at least a portion of hybrids and determine them during grow-out based upon the recessive potato-leaf gene? In other words, is there still a window of opportunity to effectively cross pollinate given this situation? The mother plant is a brandywine, the flowers look weird/different to me, and I'm wondering about timing....

Third question: how many flowers should I remove from the father plant in order to ensure a large enough supply of pollen to fertilizer the mother? One, two, four flowers?

This is my first attempt at hybridizing anything. What I'm trying to do is create a tomato that tastes like brandywine, thrives under arid conditions and is more productive. I know about brandyboy, but I think what I'm trying to do is different (don't ask about the pollen doner 'cause I ain't giving it away). This hybridizing thing appeals to me and any suggestions will be greatly appreciated.

Thanks,
HPD


Follow-Up Postings:

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RE: Tomato Hybridization Questions (good ones)

Determinate habit is recessive to indeterminate, if I remember rightly, and semi-determinate is actually controlled by a separate locus.


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RE: Tomato Hybridization Questions (good ones)

Tomatoes were originally pollinated by solitary bees. The anthers release pollen when they are buzzed. I tap the flowers whenever I pass them to be sure they get pollinated.

If you watch very closely -- a magnifying glass wouldn't hurt -- you may see a jet of pollen shooting out when the flower is tapped.

If your flowers were self-pollinated, it still may be possible to pollinate them again. In apples the second pollination may produce more seeds than the first. There are reports of cases where a mixture of pollen produce offspring with traits from two different "fathers", but this does not appear to be very common so don't worry. You should be able to sort out the seedlings.

If you're looking for drought tolerance there is another way to go about it. This involved exposing the pollen to polyethylene glycol, a drying agent. This is just "survival of the fittest" applied to pollen.

R.L. Ravikumar, B.S. Patil, P.M. Salimath, Drought tolerance in sorghum by pollen selection using osmotic stress, Euphytica, Volume 133, Issue 3, 2003, Pages 371-376

Abstract: A pollen selection study for drought tolerance using Poly Ethylene Glycol (PEG) as a selective agent was conducted in sorghum. Ten genotypes of sorghum suitable for post rainy season were crossed to cytoplasmic male sterile line 104A and three genotypes to 116A producing 13 hybrids. Two sets of 13 hybrids with and without pollen selection were produced. PEG at 36 per cent was applied to stigma and stylar tissue one hour before pollination for pollen selection (selective fertilization) and no treatment for control (nonselective fertilization). Hybrids thus produced through selective and non-selective fertilization were tested in moisture stress environment during post rainy season. The hybrids obtained through selective fertilization produced significantly higher mean grain yield compared to hybrids obtained through non-selective fertilization. The results indicate that selective fertilization through in vivo pollen selection using PEG as selective agent was effective in improving moisture stress tolerance of the progeny in sorghum genotypes studied. Further, the pollen selection also had influence on plant height, panicle length, panicle width, panicle weight and grain mass. Thus, the pollen selection had a significant effect on grain yield through its components and developmentally related traits. Pollen selection for osmotic stress tolerance in sorghum influences the growth and vigour of the plants resulting in superior progeny in moisture stress environment. The analysis of individual crosses indicated that pollen genotype selection was able to favour performance of the progeny. However, the pollen selection had positive effect in majority of the hybrids and the study demonstrates the transmission of the selected trait from pollen generation to progeny.

Another possibility is the graft hybrid. Find some drought resistant relatives of the tomato, graft your 'Brandywine' to these and self-pollinate. A recent study has shown that 'genes" are actually transmitted across the graft union.

Karl

Here is a link that might be useful: Tomato Graft Hybrids


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RE: Tomato Hybridization Questions (good ones)

Knock it off with the graft-hybrid bullsh*t, Karl Marx. Mendel was right, you are wrong. The Russians starved while Americans got fat. It's over. You lost the Cold War. Peace out, Lysenko.

PS - I'm on to you. I've read a number of your posts and it's clear to me that you've got some kind of mental disorder. Lay off the Lysenko Kool-Aid, comprende? You're such a liar that you even pretended to be someone else and posted to that alter ego (Member Tom) in an attempt to bolster your position. The give away is the use of your tag line, "Here is a link that might be useful" when posting as "Member Tom" instead of Karl.

Looking for list of plant traits (dominant/recessive) CACHED GOOGLE COPY

High Plains Drifter, a Mendelian American hero with a well-honed bullsh*t detector.

Peace out....


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RE: Tomato Hybridization Questions (good ones)

You are a funny guy.

My name is Karl, not Tom. We are, in fact, two distinct people who happen to share an interest -- and it isn't politics.

And my name is not a reference to Marx. My military father would have beat your backside for even suggesting it. In fact, my family is predominantly Celtic, if that matters to you, and I was named for the C&W singer Carl Smith. My parents changed the spelling to match our surname.

It may amuse you to know that Soviet Mendelists denounced Lysenko as anti-Marxist. In their view, Mendelism was the truly Marxist system. In the end, neither Morganism (neo-Darwinism) nor Michurinism (developmentalism) has anything in particular to do with politics.

It is useful to consider how much has been learned about heredity in the past half century. No one back then knew anything about epigenetics, plasmagenes, microRNAs, and so on. At the time most neo-Darwinists stubbornly refused to acknowledge even the possibility of cytoplasmic inheritance, which is now an accepted fact of life. Lysenko was right when he suggested that organelles are involved in heredity. The Mendelists, stuck with their archaic notion of immutable hereditary material residing exclusively in the nuclei, were wrong.

Yes, Mendel was right that some few traits will segregate in fairly predictable patterns. But the Mendelists who came after him were wrong to claim that ALL heredity could be reduced to this simple mechanism.

C. D. Darlington was an ardent neo-Darwinist and outspoken critic of the Michurinists. He went so far as to denounce both Ivan Michurin and the American Luther Burbank as "scientific frauds". He even claimed that science proved that the upper classes inherited better genes than "the poor". You'd probably like him.

But take a look at what he wrote about plasmagenes in his book, The Evolution of Genetic Systems (1958). (link below) Graft transmission of hereditary traits, and even (shudder) a change in heredity that follows development, which is precisely what Michurin claimed.

Who won the debate over the nature of light? Is it particle or wave? In fact, both paradigms are valid.

Did Cartesian geometry finally triumph over Euclidian? Of course not.

Mendelism and Developmentalism are no longer contradictory. Both sides of the great controversy erred by claiming to have a monopoly on the whole truth. Neither did.

We still don't know the whole truth about heredity, but we should have learned enough not to get caught up in foolish name-calling.

Karl

Here is a link that might be useful: Darlington on Plasmagenes


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RE: Tomato Hybridization Questions (good ones)

Maybe it has something to do with heredity, I dunno, but after reading all that stuff, my head hurts. Are weak intellectual constitutions and eye strain dominant, I guess? Whew!

Anyway, High Plains Drifter, here are some addresses to cut and paste into your search engine window (since I haven't evolved sufficiently to provide automatic electronic hyperlinks ... gosh, with my diminished capacities, it was a real task to even spell that):

http://cuke.hort.ncsu.edu/cucurbit/wehner/vegcult/tomatoai.html

http://cuke.hort.ncsu.edu/cucurbit/wehner/vegcult/tomatojr.html

http://cuke.hort.ncsu.edu/cucurbit/wehner/vegcult/tomatosz.html

What you will find are lists of hundreds of tomato cultivars with descriptions of their applications (whether they are applicable to heat tolerance, for instance ... like Gulf State Market, Creole, Bradley, etc.), and even some parentage info.

I hope the lists will be helpful in your search for genetic material to develop your super race of t'maytur.

As far as your original question, this is the first year I've attempted to cross pollinate myself; but I can tell you this:

1) I was told (by a knowledgeable member who shall remain unidentified) to only emasculate flowers that were in the early stages of showing color and had not opened or revealed their stigma. However, I emasculated 3 Cherokee Purple flowers that were clearly showing stigma and pollinated them with 3 separate contributing pollens (one "male" varietal contribution source per flower), and 2 of the 3 flowers set fruit while not one of the flowers that were on the same plant set fruit during the same high temperature period of time. It remains to be seen if those two fruits produce hybrid seed.

2) In another case, during the same very hot period of time, I emasculated two Green Zebra flowers whose pedals had spread but whose stigma were still tightly encapsulated by the whatchamacallit pods. I let the exposed stamen sit for about 30 hours, and then pollinated by smearing the stigma with broken open male parts from a yellow cherry tomato (I'm after clusters of small, tart, crunchy, striped, ping pongs with more yellow at ripe stage). One of the two flowers set fruit while not a single other flower on the GZ set fruit during the same period of time.

My assumptions thus far (based upon very limited experience and training in this whole thing):

A. Either I pollinated the blossoms that I emasculated with their own pollen as I tore off the male parts; or

B. I succeeded in pollinating the blossoms with the intended pollen from the male contributors; or

C. The blossoms were already pollinated, and I just got lucky enough not to destroy them; or

D. The stigma were pollinated by some other means after I emasculated them.

My assumption that I succeeded with my intent is only bolstered by the fact that not one single other blossom existing at the time of my activity set fruit on the two plants I was working with. It was during the hottest part of July with daytime temps running 94 to 102 here in S.W. Indiana.

As to your question about "how many flowers" to gather contributing pollen from ... it's just too damned tedious to go through tapping, capturing, drying, blah, blah, blah, as described in the scientific literature I read ... so, I just tore off 5 or 6 blossoms (from each intended contributor) that looked ripe or overripe, tore them open, and gently brushed the receiving stigma with the torn parts. I washed my hands with hot, soapy water inbetween each procedure.

I ended up having lots of yellow dust on my fingers when I did this, so I assume I got the job done. We shall see next year, right?

Regards, Bill (a flatland hybridizing neophyte)


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RE: Tomato Hybridization Questions (good ones)

Are you people for real????
Good grief! Grow up, get a life!
Ana


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RE: Tomato Hybridization Questions (good ones)

Karl and I have argued plenty, but in his defense, the "Here is a link that might be useful" line is automatic, I think.

Here is a link that might be useful: See?


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RE: Tomato Hybridization Questions (good ones)

I never used but one flower as a male on a given female flower.
After emasculating an un-opened flower to be used as a seed parent, I'd pluck a flower from the prospective pollen parent and using my fingernail and thumbnail, cut off the anther cone just at it's base. Then I'd stick the anther cone onto the stigma and style of the seed parent flower and leave it.
I think I need to define my terms better. The anther cone is the cone made by the anthers. Smaller tomatoes like cherry tomatoes, especially, will have anthers that stick together in a cone, if handled gently. Beefsteak type tomatoes have anthers that are more spreadout and don't hang together in a cone. Working in a hot, dry climate, I was generally using at least one small tomato in my crosses. I always used the smaller tomato variety as the pollen parent because it was easy to cross this way.
The anther cone generally fit tight and kept other pollen out.
During tomato pollinating season, I used to use red fingernail polish on my left thumbnail. I'd tap an anther against it and I could see pollen grains against the red fingernail polish.
And finally, if you mark and watch a given tomato flower daily, you can soon learn to tell the day before the flower will open. That is when I'd emsculate and put the anther cone on.
Currant tomatoes had styles so weak that the anther cone would destroy them when I tried to apply it. I only used currant tomatoes as male parents for that reason.
Most cherry to Marmande or Roma size tomatoes would work as either male or female with this method.


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RE: Tomato Hybridization Questions (good ones)

Great reading I tryed cross polinating last growing season but had no sucsess not enough dedacated time to the project due to work and other comitments, will try again next growing season.
Was wondering if anyone knows of any good sites with illustrations or photoes regarding cross polinating of tomatoes,
Keith.


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RE: Tomato Hybridization Questions (good ones)

darwin, see if this might be any help. http://www.avrdc.org/LC/tomato/hybrid/01title.html geol


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RE: Tomato Hybridization Questions (good ones)

goodonya and many thanks geol, just the site i was looking for. keith


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RE: Tomato Hybridization Questions (good ones)

Thanks! I found this Thread very informative.


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RE: Tomato Hybridization Questions (good ones)

This might help those in search of basic pollination information as for those who are in need of help it won't do much good.

Variables occur in all nature as nothing is absolute. A dark gene is always supposed to be dominant and yet cases will occur from mammals to plants of the light gene dominating. No one knows by God what one will come up with and is why you see names like Doucet 2110. That usually means there were at least two thousand one hundred and ten plants and out of all of those this was the only one which behaved.

The stud which threw most of the race horse champions looked like a plug who pulled plows. Tomatoes are no different and variables always come into play and is why there are so very few good varieties which ever make it to the market.
agtG

http://www.kdcomm.net/~tomato/Tomato/xingtom.html

Here is a link that might be useful: Hybrid Seed Tomatoe Production


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