How Do You Maintain A Landrace?

[raymondo]

Holly, once you've chosen your best initial plants and put them together, they will cross, no doubt about it. That means the saved seed will contain lots of F1 hybrids (don't know if turnips can self). Even if you planted out this seed by plant (like planting corn cob to row), you'll be planting out hybrids, and mixed hybrids at that - different fathers. What I'm getting at here is that even kept separate you won't end up with just Joseph's Purple, though you may end up with a mix dominated by those genetics.
It comes down to what you want from the mix. For example, my collard mix is simply that, a mix. I want more diversity in colour and leaf texture. I may end up selecting out several lines with distinct characteristics, but that's not the aim, at least not now. The aim of my melon mix is to get a tasty green melon that does well in my coolish summers and in my heavy clay soil. I don't care much about size or shape, just flavour, and possibly yield, though ripening fully is priority number one.

[Joseph Lofthouse]

When a new variety comes into my garden, I am ruthless about culling. For example, two years ago I planted some "orange turnips". They grew OK, but my people hated them, so I didn't grow them again. When I started my spinach landrace, less than half of the planted varieties were allowed to go to seed.

My primary selection criteria is productivity... If a plant doesn't thrive in my garden and produce edible food, then there is little sense having it regardless of any diversity that it would bring with it. I wouldn't be opposed to letting an orange turnip go to seed among my purple top turnips, but it would be like 1 orange per 40 purples. That brings in genetic diversity without swamping the crop with undesirables. And even then, I might only save the seeds from the hybrids, and not save any seeds from the orange plant.

I like hybridization as a way of introducing new genetics into my landraces. That way, the collected seed contains at least 50% of my original genetics, and if something goes awry, the seeds contain all of the necessary components to reconstitute the landrace. (A little bit of bright lights Swiss chard pollen among the beet seed is very nice!)

I grow different seeds for different reasons:

If I am growing something primarily for production in a crop that already does very well for me: such as my turnips, I just plant them and save seeds from the most productive 20% of the plants in the patch: however I am defining productivity today. I might add foreign seeds or roots to the crop from time to time, but always in small percentages. And I might save something only for it's diversity, but again in small quantities. I have phenotypic and agronomic and culinary goals in mind for each crop, and as long as 95% of the crop meets those criteria I am happy as a sandy beach on a sunny day.

If I am trying to adapt a plant species to my garden, that does poorly here, I jumble all the seeds together the first year and save seed from everything that survives. The second year I'll save seed from a few of the most productive. By the third year I'm treating it like a plain old production crop. (For beans/peas I save a higher percentage of the crop.)

Then there is the plant breeding!!!! This is where anything goes... I'm intending to make a post to the Astronomy Domine thread after I get everybody's seeds shipped, in which I detail how I prepared this year's Astronomy Domine for sharing... But the gist of it is that I grew a patch of white seed, and a patch of orange seed, and a patch of gray seed, and a patch of sugary enhanced seed, and a patch of mixed seed, etc and combined them together via a formula, so that the resulting crop will look really clever!

With a couple of crops I maintain hybrid swarms... A crossing block where new genes are constantly being added, and mixed up, and jumbled around. I'm primarily looking for new and exciting traits. These are the things that are so far-out that there is no telling what phenotype might show up. This group is as unreliable and unstable as heck. (Bok Choi crossed with Turnip.) Nothing leaves this group and goes into a production group until it has grown a year or two by itself and acquired some stability. I like diversity, but I grow for the sake of production, and I have to be able to trust my mainstays.

I can be perfectly happy with saving all of the seeds from a particular species into the same seed packet. I am also more than willing to create sub-varieties for any reason that suits my fancy. If I want to grow a patch of all white corn, and a patch of only orange corn, and a patch of popcorn, then I just do it. If a seed produces a plant that totally does not fit my goals, but it is really clever all on it's own, then I am delighted to save it as it's own variety. (This year for example I saved out a collection of pumpkin-gourds. Gourd shaped pepos weighing about 2 pound each. That seems clever to me.)

So Holly: define your goals up-front. Why are you growing turnips? What do you want your turnip patch to look like in 5 years? That aughta make it easier to decide how to get there... You could grow turnip seed on a rotating basis... The first year make purple turnip seed, the next year orange turnip seed, etc...

My goal for turnips is to have a highly productive crop that looks and tastes like the only socially acceptable turnip in my village: So to me, that means "Purple Top White Globe" with whatever small percentage of diversity that I might sneak into it.



But I'm only growing socially unacceptable corn! What the heck!!! I am so fickle. The first year I grew Astronomy Domine I had a lady tell me that I'm a bad farmer for letting a colored kernel from the Indian corn contaminate the sweet corn that I sold her!!! I can hardly wait till next year when almost every cob in the sweet corn patch will be contaminated!

[raymondo]

It's always good reading your thoughts on maintaining landraces Joseph. I seem to always come away with something new.

[12540dumont]

Why selfers don't get inbreeding depression and outcrossers do. This was a talk given by John Navazio. John is one of the only biennial crop experts I have come across.

This has helped me figure out what can happen to my turnip experiment a few gens down the road.

As Joseph said, I have to figure out where I'm going. And then I have to figure out if where I'm going is where I should be going.


www.growseed.org/selfersandcrossers.html

So...I can't choose for eating quality? Can I just chose for just brix?

[Joseph Lofthouse]

Feb 3, 2012 3:10:28 GMT -5 12540dumont said:

So...I can't choose for eating quality? Can I just chose for just brix?

You can easily select your turnips for eating quality... During the growing season, when it's at it's best for fresh eating, take your knife and slice a piece off. Eat it via your preferred method (raw for me). Then let it continue growing and save the best tasting mangled roots for next year's seed. They'll grow just fine after you've taken a bite out of them. I don't know how you explain the missing piece to your CSA members though... I eat a cob of corn 3-4 times during the growing season.

[ottawagardener]

People do the same thing for carrots. I forget the term for it but it's called stippling or something? Anyhow, sampling the bottom bit to taste for quality before replanting the best.

[kwilds]

I was wondering about how to select root crops for flavour! I never even thought about slicing a piece off!

[12540dumont]

Joseph,

It was John who told me that if I select for flavor, my race will eventually die unless I keep adding new genetics to it.

So, I was thinking, maybe I should select the best tasting from each of the kinds and keep replanting them together?

[Joseph Lofthouse]

John said, "If you just selected for eating quality and that's all, you'd lose everything." Then he used the example of buttercup squash, which originated as a single seed, and suffers mightily because of it.

With our landrace breeding, we are selecting for multitudes of traits in addition to taste: Some of them deliberate, and some of them accidental. We are growing dozens, or hundreds, or thousands of genetically diverse pollen donors for each crop. We have the luxury of selecting for taste without worry that we'll lose our crop to inbreeding depression. And even if we do, it's a landrace! So we just introduce some more diversity.

We have inherited some pretty sad crops: For example potatoes and garlic. Perhaps we will be able to overcome the sadness and leave them in a better state for our grandchildren.

[12540dumont]

Yes, I am despondent over my potatoes....I've gone from 22 kinds to just 2. The darn things have given up the will to thrive. I suspect its just poor genetics.

I rue the day that I brought in potatoes from a "seed company". This is what I got.

I need to start all over again. 10 years down the tubes.

Attachments:

[nuts]

I think simply that you can say that how heavy you can select depends on your minimum populationsize.

That means that for each generation you take the seeds from a minimum number of plants.

Say that you fixed your minimum at 50 plants,so if you have a field of 1000 plants you can select one of twenty plants as parents and you can be severe in your selection criteria,if you have only 50 plants you cannot do any selection at all.

The problem is to know what the minimum population size is,for a given plantspecies.
Sometimes you see some ciphers,specially for plants that risc inbreeddepression.

Then there are sophisticated mathematical calculations that maybe give some handles.
(about drift and geneflows and such)
For the moment I prefer rough guessing though

[templeton]

This interests me, since I want to do some parsnip selection. I've got a limited amount of space, so was thinking of trying some cross-season swapping - Sow seed from say 4 different varieties, select, cross them up, harvest seed, sow new seed the next year, select, cross, harvest seed, mix the seed lots, sow half etc etc.
Would this strategy work, or is there a more sophisticated approach I could use?
T

[Joseph Lofthouse]

I might only save seeds from 50 plants each year, but I am planting seeds from many more mothers than that... Because I plant last year's seeds, and some 2 year old seed, and some 3 year old seed, and some seed from my collaborators and neighbors, and in some years seed from outsiders, so that by planting time a couple hundred mothers may have contributed seed.

With an annual, like corn, the number of fathers represented could be as high as the total population of my corn over the past 3 years, plus the total corn population of my collaborators and outsiders. Most of what I get from outsiders I consider to be functioning as clones.

With out-crossing biennials like carrots, I target 36 plants as my minimum. By the time I plant 3 years worth of seed that's 108 mothers represented in the landrace.

By the rough guessing method, I'd wonder if I should pay more attention to the biennials since the pool of pollen donors is limited. If I have 5000 possible pollen donors in the corn patch that seems like more than enough.

[Joseph Lofthouse]

Feb 7, 2012 17:00:32 GMT -5 templeton said:

This interests me, since I want to do some parsnip selection. I've got a limited amount of space, so was thinking of trying some cross-season swapping - Sow seed from say 4 different varieties, select, cross them up, harvest seed, sow new seed the next year, select, cross, harvest seed, mix the seed lots, sow half etc etc.
Would this strategy work, or is there a more sophisticated approach I could use?

I love cross season swapping. It's a great way to increase the size of the genepool while minimizing the total number of plants growing at any given time.

Some species work better for this than others... I hear rumors that old parsnip seed germinates poorly. Poorly is not a problem: You just plant extra heavy. No germination of two year old seed would be a problem. Even without viable old seed, parsnips might respond well to cuttings: Making clones of the mother plants and maintain the clones without allowing them to go to seed until the second or third years.

[raymondo]

I've heard that fresh dry parsnip seed will keep for a number of year if frozen, 3 being the number mentioned.