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Post by gilbert on Feb 2, 2016 18:56:04 GMT -5
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Post by diane on Feb 2, 2016 19:25:23 GMT -5
Well done!
Just one omission I noticed: Of course, standard seed saving practices still much value. missing the word "have"
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Post by raymondo on Feb 3, 2016 0:52:40 GMT -5
Nice one Gilbert. I like the explanation. Clear and easy to grasp. Noticed two typos: - Maintaining a landrace is far easier
then than maintaining ...
... - Landraces are unique ... And the individual plants may be different
then than any heirloom ...
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Post by templeton on Feb 3, 2016 3:25:51 GMT -5
A nice, clear explanation. Well done. It's always possible to split horticultural hairs, but that might be the topic of another post.
T
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Post by gilbert on Feb 3, 2016 12:40:48 GMT -5
Thanks for catching the mistakes everyone, I will go fix those.
Any suggestions for hairs to split, templeton?
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Post by templeton on Feb 3, 2016 16:23:25 GMT -5
Gilbert, I'm loath to even mention them, because your explanation is excellent, and really needs no modification. but if you insist... Some people like to reserve the term landrace for traditional crop assemblages. I have no problem with it's more modern use, but to placate them, sometimes adaptavar landrace is used. Google it, but there is a lengthy description here homegrowngoodness.blogspot.com.au/2011/08/persuit-of-landrace-genetic-or.html , by Alan Bishop, on his 'home' blog. While it is true that growing a single variety will keep it 'pure', there is some discussion that even this, by growing in a single location and/or in small numbers exerts selection pressure on the population, so changes will develop between a single variety grown in different locations by different growers. The availability of different 'brandywine' tomato strains (which i have not grown, so this is heresay) is probably a case in point. Also noticed another typo para 7, landraces rather than land races. In that para, using tomatoes as an example is probably not the best example - tomatoes are hard to landrace because of their self-pollination tendencies; another vegetable like butternut squash might be better. We could go into the whole discussion about how we have so modified some vegetables that re-establishing genetic diversity is problematic - garlic, saffron, shallots - and tomatoes- come to mind. I'm not sure you can sustain the argument that "In fact, landraces really shine in marginal climates. Most seeds are grown and varieties bred for mild, wet climates..." They may be more useful, but I'm not sure the implication that they are either better or worse in marginal conditions is true. And there are many crops that are specifically bred for what you describe as 'marginal climates'. It's all relative. marginal for you might be mainstream for me. (I'm reminded of a comment by an old aboriginal man when asked about how it felt to live in a 'remote' area - he replied that Sydney was remote from where he lived in the Western Desert...). Perhaps 'widely available' varieties, or 'common commercial varieties' might be a better choice. But really, these are very thin hair splits. don't change it. T |
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Post by gilbert on Feb 4, 2016 15:30:44 GMT -5
Hello Templeton,
Good points.
I put quotes around the word landrace in the title because of the word issue.
I agree, tomatoes are probably not the best example. On a side note, would adding pimpinelifoilium species to a tomato landrace change the inbreeding characteristics? I'm following the projects on here to restore fertility to garlic.
About adaption of pure varieties; yes, I guess so. Would they have to have variability to start with? Also, if mutations/ gene drift showed up, wouldn't a really strict genetic preservationist rouge them out? Anyway, I might modify it to say that landraces carry more adaption potential.
Marginal climates: I guess I should modify it to say that landraces can be adapted to marginal climates more quickly then commercial varieties.
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Post by templeton on Feb 4, 2016 22:51:03 GMT -5
Hello Templeton, Good points. I put quotes around the word landrace in the title because of the word issue. I agree, tomatoes are probably not the best example. On a side note, would adding pimpinelifoilium species to a tomato landrace change the inbreeding characteristics? I'm following the projects on here to restore fertility to garlic. About adaption of pure varieties; yes, I guess so. Would they have to have variability to start with? Also, if mutations/ gene drift showed up, wouldn't a really strict genetic preservationist rouge them out? Anyway, I might modify it to say that landraces carry more adaption potential. Marginal climates: I guess I should modify it to say that landraces can be adapted to marginal climates more quickly then commercial varieties. Hrrmph! I thought I just told you not to change anything!  T |
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Post by gilbert on Feb 4, 2016 23:01:36 GMT -5
Hello Templeton,
I'm thinking about it. (Changing things.)
I hate websites that spread oversimplified information!
But I'm starting to think that I could split some hairs in future posts. I plan to post a lot more on my site as my projects get underway.
Basically, I'm planning to start a landrace of every crop plant I grow next year. I've always wanted to save my own seeds, but I'm a perfectionist and very busy, with the result that, since I can't do a thing perfectly, it does not get done. The concept of landraces is really freeing.
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Post by templeton on Feb 5, 2016 0:05:32 GMT -5
Hi gilbert. A simple note at the bottom that there are a few other complexities to be explained in another post relieves you of the need to cut it all up, and you can delay the 'perfect' explanation for a while. I agree, the escape from genetic 'purity' is liberating. Re S.pimp in tomatoes, have a look at joseph's work on promiscuous tomatoes. DarJones has written a few good posts on this too, i think. Re. drift in pure varieties, there might be small differences not caused by single mutations, but caused by multiple genes interacting, that aren't readily apparent - If you and I both grow from the same seed source, we are unlikely to pick exactly the same traits unwittingly, since our climates and soils are different. We might intend to be scrupulously 'true to type' selecting for example big fruits, with the right shape and colour, but we will both selecting for those that do best in (our different) environments, just by the number of seed we collect from productive versus weak plants. Hope this isn't too laboured an explanation. T |
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Post by kazedwards on Feb 5, 2016 0:24:03 GMT -5
gilbert it was a great read. Well written!
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Post by reed on Feb 5, 2016 4:24:42 GMT -5
Basically, I'm planning to start a landrace of every crop plant I grow next year. I've always wanted to save my own seeds, but I'm a perfectionist and very busy, with the result that, since I can't do a thing perfectly, it does not get done. The concept of landraces is really freeing. I agree completely. On genetic drift within a variety, I have a bean that looks much different than the ones I started with several years ago. All I ever did was favor clean dry pods with nice blond color. I suppose I might have also favored larger seeds. What I have now is probably 20% larger seeds with lighter color than the originals. |
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Post by gilbert on Feb 5, 2016 10:35:44 GMT -5
Thanks Kazedwards!
Hello Reed,
So what is the mechanism of genetic drift? Was the diversity already there, either as variation plant to plant, or as some sort of hidden level? Is it epigenetics? Or mutations?
What about all those weird fungi, endophytes and such, which live in plants? Could they change location to location?
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Post by reed on Feb 5, 2016 12:07:34 GMT -5
Gilbert, I wouldn't venture a guess on the mechanism. I don't know that the change I'v seen, especially in that one bean isn't environmental. I suppose though that some existing genetic diversity could be in play. It is generally humid here at time beans are drying down and splotches on the pods, I assume from some kind of mold or fungus are extremely common. I try to save my seeds from pods that have less of that. It varies between varieties and within single varieties.
So I don't know. Were the plants that have less of it (the mold) also genetically prone to larger, lighter colored seeds? Or does it (the mold) some how interfere with the seeds maturing and causes them to be smaller and darker? In any event almost all of the seeds now are the larger lighter variety.
I also don't know what caused my "Particularly Productive" Rutgers tomato. Two or three years ago it just showed up and made as many as any four others put together. I figured it just got lucky water or nutrient wise but it's children since then have been the same.
I'm too far behind, education wise, on the technical science of breeding and genetics and while I find it interesting to read about I'm mostly going with a plant it and see what happens approach.
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Post by keen101 (Biolumo / Andrew B.) on Feb 5, 2016 15:29:21 GMT -5
Overall i think its a good post. Templeton is right that the word landrace can be splitting hairs, but oh well. I like the term "modern landrace", but in the article i posted under the thread "evolutionary plant breeding" the author doesent seem to truly like that term. Lol.
I do tend to shy away from using it with highly inbreeding crops like tomatoes or peas, but then again, if i were to interplant them year after year would they too not eventually become one even if they never cross pollinated each other?
So its a mute point. Plus josephs exerted stigma tomatoes / promiscuous tomato project has lots of merit. Quick question, could introducing a self-incompatibility gene to josephs project be a good thing to increase diversity? Do self-incompatibility genes even exist in tomatoes?
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