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Post by littleminnie on Mar 20, 2015 22:35:56 GMT -5
The Survival Preppers Expo contacted me about teaching their seed saving class. I agreed tentatively. Its not really my crowd but good place to start. Garden Class at ExpoI have had a severe cold all week but already had the info ready from last summer. I just have to make it about 45 minutes. I will post more later.
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Post by littleminnie on Mar 22, 2015 19:56:48 GMT -5
Does anyone want to give the real simple explanation of cell fusion vs regular hybrids?
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Post by steev on Mar 22, 2015 20:06:23 GMT -5
I think one happens in a lab and the other in the field.
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Post by philagardener on Mar 22, 2015 20:30:28 GMT -5
In cell fusion, single cells (termed protoplasts) from different plants are stripped of their walls and fused in the lab, and then sterile tissue culture techniques are used to recover plants. The fusion product starts with two diploid nuclear genomes (and two cytoplasms), although chromosomes can be lost as regeneration proceeds.
Because this approach does not rely on the normal processes of sexual reproduction (how a hybrid plant is generated by pollen fertilizing an ovule, and seed developing on a mother plant) it can be used to generate offspring that would not normally be possible from regular crosses. For example, this permits traits like disease resistance to be brought in from wild, related species when sexual hybridization between that wild species and the cultivated one is not be possible. Cell fusion can also be used to transfer traits like CMS (cytoplasmic male sterility) or generate CMS conditions because of genomic conflicts in the offspring.
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Post by Joseph Lofthouse on Mar 22, 2015 20:43:41 GMT -5
Does anyone want to give the real simple explanation of cell fusion vs regular hybrids? Mitochondria have their own DNA which is separate from the DNA inside the nucleus. During flowering, the nuclear DNA is split in half: Half goes into the ova, and half goes into the pollen. It is recombined into a full set of DNA inside the seed. The pollen does not contain mitochondria. The ova contains the mitochondria that are passed on to the seed. So the mitochondria's DNA is inherited only from the mother. Sometimes, the mitochondria is defective. That might cause a plant to fail in some way or other, such as not being able to make pollen. That is great if we want to make a hybrid, because any pollen has to come from a different plant that doesn't carry the defective mitochondria. Makes it trivial to create hybrids with plants that have little tiny flowers. The seeds also inherit the defective mitochondrial DNA, thus succeeding generations likewise fail to make pollen. For practical purposes of seed saving, you only need a few pollen producing plants in order to pollinate a patch of mostly pollen-sterile plants. But you need some source of pollen. I tried saving seeds from male-sterile sugar beets one time. No seed was produced because there was no pollen available. Cell fusion genetic engineering happens in a laboratory, and is the process of moving defective mitochondria into new species that didn't previously contain that particular defect. The reason to do this kind of thing is to be able to make hybrids easily in species that were previously difficult to hybridize on a commercial scale. It also imposes anti-copy protection on the seed, because the offspring will not produce pollen.
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Post by templeton on Mar 23, 2015 0:28:58 GMT -5
Does anyone want to give the real simple explanation of cell fusion vs regular hybrids? Are you going to make it to advanced topics like that in 45 minutes? I'd side step it if i was you. Most folks would just be flummoxed by the language, if not the process. I think Joseph's and Phila's replies indicate that there isn't a real simple explanation...Simple rule, avoid hybrids - advanced students might want to try de-hybridising, that's another 10 bucks and another 45 minutes, i reckon - master class ... ...and are you going to do fliers or something for an advanced hands-on day at your place? You were thinking of that weren't you? might be a good marketing opportunity. Just a thought. T
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Post by steev on Mar 23, 2015 0:52:33 GMT -5
I think my dumb-ass explanation was the simple one; it just got more complex thereafter; not less useful, mind you, but more complex, which can be sometimes less useful for the less wonky.
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Post by Joseph Lofthouse on Mar 23, 2015 1:14:13 GMT -5
Steev's explanation definitely wins the gold star for this thread.
Can I withdraw my entry???
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Post by littleminnie on Mar 23, 2015 17:29:10 GMT -5
No I am not going into cell fusion in this class which is good because I could not explain it. I do want to mention it. I want to be able to proclaim truths the usual seed saving teacher would not, like yes you can save seeds from hybrids. If not, we would have only one variety of each thing! But I could not even mention the term cell fusion at all. I know it only is a transfer of material from two like plants of the same species, unlike GMOs which are two very different entities. I have never understood when the trans-gening happens in GMOs exactly.
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Post by littleminnie on Mar 25, 2015 17:25:15 GMT -5
They have made the class free with paid admission to the expo so now I am going to shorten it and make them want to come to the one in the garden this summer. I just have to figure out what all to cut out. I had it pretty done despite having the worst cold in 18 years. Now to cut and time.
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