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Post by Joseph Lofthouse on Sept 26, 2011 11:54:21 GMT -5
Johno: Were you using carrots with cytoplasmic male sterility? Most grocery store carrots and all F1 hybrids carry that trait these days... If the parent plants were male sterile any seeds produced were pollinated by QAL. I checked a few seed catalogs (even organic ones). Around 90% of offered carrots were (male sterile) F1 hybrids. I guess I had the unintentional luck of starting out with at least a few open pollinated carrots, and managed to select some male-fertile carrots in each succeeding generation.
I always thought the talk about terminator genes was nothing more than hype... But it seems to have affected at least one of my friends. I hate the Russian roulette nature of my current carrot breeding program. What if this is the year that I finally eliminated every male-fertile carrot plant from my seed patch?
Gee my head is spinning. Trying to think about how to eliminate cytoplasmic male sterility from a crop while still retaining the characteristics of the crop. It seems to me like a case of once-poisoned always-poisoned.... I can plant enough pollen donors within a patch to swamp out any pollen drifting in from elsewhere, and pollinate the male sterile plants, but I really really really dislike the idea of allowing half-sterile plants to grow in my garden.
It's easy enough with potatoes to select for plants that release pollen: just tap the flower when the sun is shining brightly and pollen will pour out of the flower. That's easy to see. That also eliminates like 95% of my potato genome. Perhaps I aught to just pay the price and make the choice to eliminate male sterile potatoes from my garden. What if Tom W had made the choice 50 years ago to eliminate all male sterile potatoes from his breeding program. I wonder where we would be today?
I'll also give some thought to the idea of eliminating other male-sterile plants that may have inadvertently crept into my seeds.
With carrot there are two different manifestations in the flower of male sterility, either the anthers are replaced by a whirl of petals, or the anthers are brown.
I wonder how corn male sterility manifests itself?
Onions are another crop in which male sterility is rampant.
Oh, Oh.... Looks like another chapter needs to be added to the book I'm supposedly writing: "Eliminating Cytoplasmic Male Sterility"
I sure love the collaborative nature of this group, and how our knowledge explodes as we bounce ideas off of each other.
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Post by Joseph Lofthouse on Sept 26, 2011 13:43:37 GMT -5
I found this reading his site: Now if I can just find something on jumping genes! Breeding of varieties, that can transfer the blue grain colour trait by pollen, is quite difficult. In most blue varieties inheritance of the blue colour is only maternal and will not be transfered by pollen in a visible way. In some blue varieties the colour is also not reliable because of jumping genes or inhibitory allels in yellow varieties. All of the blue kernels in this photo are a result of the blue trait being transferred by pollen onto a plain old boring sugary enhanced sweet corn. I don't have a reliable blue pollen donor yet... Just the possibility.  |
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Post by johno on Sept 26, 2011 13:56:05 GMT -5
Johno: Were you using carrots with cytoplasmic male sterility? Most grocery store carrots and all F1 hybrids carry that trait these days... If the parent plants were male sterile any seeds produced were pollinated by QAL. I checked a few seed catalogs (even organic ones). Around 90% of offered carrots were (male sterile) F1 hybrids. I guess I had the unintentional luck of starting out with at least a few open pollinated carrots, and managed to select some male-fertile carrots in each succeeding generation. In the first case all the varieties came from Baker Creek, one was Kuroda long and I want to say another was Atomic Red. Maybe others?.. In the second case: Oxheart and St. Valery. So I don't think that was the problem. I'm glad you brought it up, though, because it is not something I was aware of. I would certainly have made that mistake in the future. What brought cytoplasmic male sterility in commercial hybrid carrots to your attention? Why is this common practice? |
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Post by Joseph Lofthouse on Sept 26, 2011 14:13:25 GMT -5
What brought cytoplasmic male sterility in commercial hybrid carrots to your attention? Why is this common practice? I was grasping at straws wondering why your experience with carrots is so different from mine. I haven't exactly grown huge numbers of carrot parents. It's gotta be a conspiracy... ... ... Hybrid seeds sell for higher prices than open pollinated seeds, and you gotta go back to the company every year for fresh seeds. I guess it would be possible to back-cross any open pollinated carrot onto a male-sterile cytoplasm. As long as you used the original open pollinated strain to pollinate the male-sterile strain then your seed would truly incorporate the so called terminator gene, and yet it would be perfectly correct to call them "open pollinated", or "heirloom", and even to use the same name as the original variety. We certainly have it within our power to test that hypothesis... A magnifying glass or good eyesight would be all that was necessary. |
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Post by 12540dumont on Sept 26, 2011 15:16:55 GMT -5
QAL and carrots. Honey Bees, Green Stinkbug, Golden Northern Bumble Bee, Green Lacewings and parasitic wasps all use the QAL as a food source. As QAL is very tall and carrots very short, it seems that the QAL is acting as a pollen catcher. In other words, the pollinators stop first where it is tall and then move on to the short things. I use this at my farm all the time. I plant sunflowers around anything I don't want other pollen from. The bees stop there and clean their feet and since sunflowers don't cross pepos and the bees have to cross the sunflowers again to get to the other pepos, I've been able to keep my zukes from crossing with my little green seed. Johnno, I think you are right, go straight to the row covers or pollinator cages. www.farmtek.com/farm/supplies/cat1;ft1_fencing_containment;ft1_econoline_shade_frame_2.htmlwe stole this idea and it worked great. |
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Post by ottawagardener on Sept 26, 2011 18:58:11 GMT -5
Good to know about carrots.
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Post by Joseph Lofthouse on Sept 26, 2011 20:06:30 GMT -5
I checked my garden... No Queen Ann's Lace. So I checked the borrow pit around my garden... No Queen Ann's Lace. So I drove slowly along ten miles of roads checking the borrow pit... No Queen Ann's Lace. So I checked the "Digital Atlas of the Vascular Plants of Utah"... There were a few very widely scattered results. I missed my calling in life... I should have been a carrot seed farmer in an area free of the blight of QAL pollen. So I went into my field and collected carrot flowers to take back to the laboratory... (A desk with a huge lighted magnifying glass).  75% of the carrots that I checked are male sterile.  |
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Post by 12540dumont on Sept 26, 2011 21:35:47 GMT -5
And I hope you're going to write a chapter on getting by that.
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Post by Joseph Lofthouse on Sept 26, 2011 22:49:18 GMT -5
The only way I know to get rid of male cytoplasmic sterility is to examine the blossoms at flowering time and chop out any plant that isn't producing pollen normally. There may be nuclear interactions that will eliminate the sterility, but that's too suave for me, I'm more of a brute. Chop, chop, chop.
On carrots it's easy to see with a magnifying glass, either there are yellow pollen-bearing anthers or there aren't.
With potatoes shake the blossom. Either pollen comes out or it doesn't.
I don't know what strategy I'll adopt for onions, or for cauliflower, or for corn.
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Post by johno on Sept 27, 2011 14:18:00 GMT -5
I gotta' ask: How did you know that Kuroda Long is male sterile? I mean, do you have some trade publication or an obscure link? I Googled it and your post was the first result, the rest didn't really help. Thanks again. This is a really frustrating problem, because I was planning to use some modern hybrids in breeding. Now I find out some heirlooms have male sterility, too?! I really need to know where to find this information. That's great news about your lack of QAL. And depressing news about all your male-steriles.  At least I know how to check for myself now. But knowing before they've taken up real estate for a year or more would be advantageous. And by the way, this really would make an excellent chapter... Thanks for that link, dumont. That gives me good ideas. I have most of that material on hand.  And thanks for the sunflower tip! Great idea. |
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Post by raymondo on Sept 27, 2011 15:34:16 GMT -5
A botanist at the local university reckons that many members of the carrot family develop mixed flower types - some hermaphrodite, some male only, some female only. He has noticed it most in cultivated members of this family. The implication is that some level of male sterility may be 'normal', though perhaps undesirable. Just a thought.
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Post by Joseph Lofthouse on Sept 27, 2011 15:35:30 GMT -5
I gotta' ask: How did you know that Kuroda Long is male sterile? I mean, do you have some trade publication or an obscure link? When I googled kuroda Long it was listed in the first seed catalog I looked at as an F1 hybrid. All commercial hybrids are male sterile. I don't always trust catalogs.... Perhaps Baker is growing a version that is not male sterile? |
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Post by templeton on Sept 27, 2011 23:16:56 GMT -5
Joseph,
I think your initial principle is a sound starting point, but there are a few issues that you might address:
The probability will be dependant on the density of planting - one carrot plant in your yard is more likely to be pollinated by one of your neighbour's carrots if there are no adjacent or intervening carrots. It is also dependant on the pollen vectors, how active they are, and their fidelity to a given patch of flowering plants. I think your numbers are a good illustration of the principles involved, but I'd be hedging my bets a bit rather than stating categorically that the chances are 1:1000 for a neighbourly cross pollination, for example.
I did some brief work on palynological studies in my graduate studies, there might be something in that literature about pollen rain. I know grass pollen from Southern Australia has been detected on subAntarctic islands, 2000 km away.
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Post by 12540dumont on Sept 28, 2011 12:48:50 GMT -5
Hence the hay fever. Not all pollen is alike. But I have been in Nebraska or was that Illinois when the sky was golden with corn pollen. Achoo! Some pollen is really heavy.
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Post by 12540dumont on Sept 28, 2011 18:13:17 GMT -5
Joseph
When are you starting the chapter on what to select for? I have a lot of questions when you get there....like how do I select for a corn that has a tighter package. I have a perfect corn, but some of the cobs start unwrapping themselves as they get dry. So the problem is, some of the biggest cobs do this. So here I was marking really long cobs in the field...and arghh...well so, how to get long cobs in tight packages.
In beans when I select for higher protein it comes at the cost of yield. Hmm, how not do do that.
I was looking at the following traits....
Vigor
Taste
Nutrition
Ability to tolerate drought, wind or other extreme conditions
Ability to compete with weeds Early- or late-bearing fruit (whichever is desired)
Long storage life
Late to go to seed or bolt
Good fruit texture
Disease resistant
Productivity
Cold hardiness
Resistance to insect pests
Larger fruit or flowers
Attractiveness
Color
Shape
Now some of these are mutually exclusive.
So, how's the book coming?
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75% of the carrots that I checked are male sterile. 
At least I know how to check for myself now. But knowing before they've taken up real estate for a year or more would be advantageous.
And thanks for the sunflower tip! Great idea.
