How Do You Maintain A Landrace?

[Joseph Lofthouse]

I keep landraces in two different ways depending on whether they are in-breeders or out-crossers.

With the in-breeders, I am essentially growing the same varieties every year. Rather than saving the seed as individual cultivars, I am saving the seed as groups.

Tomatoes are in-breeders with a very small percentage of cross-pollination. I ended up dividing the tomatoes into about 4 landraces based on their use/phenotype:

1- The earliest tomato that bears fruit in my garden. (Might be several plants if they are close.)

2- The earliest salad/slicing tomatoes. (From about a dozen plants) Collected during about the first two weeks of the harvest.

3- Main season slicing/canning tomatoes. (From about 30 -40 plants: maybe 10% to 20% of the plants in my garden. Lower percentage saved in years when I am doing lots of trials.) Some fruits from the earliest slicing tomatoes might also end up in this lot of seeds.

4- Odd balls. Anything else that didn't grow well enough or taste good enough to make it into one of the best landraces but is interesting enough to try growing again.

When I plant the seeds, I generally mark the flats with what is in them, but I might not. It's obvious what they are once the fruit starts ripening. It's very common for the descendants of a seed to jump into a different landrace.

I have planted hundreds of varieties of tomatoes over the years, but I only maintain those four landraces. When I receive new tomato seeds to trial, I grow 2-3 plants of each variety (without keeping records of which is what) and the left over seeds are dumped into the odd-balls landrace. If I grow 100 tomato plants in a year from my saved seed, I can expect about 5 of them to be new varieties that arose by cross-pollination in my garden, so I watch for new and interesting traits to show up. I wouldn't be adverse for example with starting a cherry tomato landrace.

My dry bean landrace is even simpler... About 50 varieties of different kinds of beans got planted. I harvest the beans as they dry down. I am not doing any selecting for suitability... I figure that plants that grow better in my garden will produce more seeds, and will be better represented in the landrace.

I screen the snap bean landrace for tender pods, and anything with tough pods gets moved into the dry bean landrace.

I don't even care technically if I mix species together in a landrace. I would be perfectly happy for example with a legume landrace: peas, beans, lentils, chickpeas, favas, all growing together in the same landrace. They all go together into the 15 bean soup, so they might as well be grown together and harvested together. It's not like I have a combine running through the field and every seed pod has to be harvested on the same day.

I noticed a few plants in my pea landrace that were 10 days earlier than the rest of the patch this year. I created a new "Earlier Pea" landrace. Next year I would like to do a planting of the landrace very late in the season to see if I can pull a summer pea landrace out of it.

If I am trialling a new variety of an inbreeder, I plant it right into the main patch, or in the next row over. I'm not worried about it crossing with my main patch.

With the out-crossers I am growing an open pollinated crossing population with tremendous genetic diversity. It might sound scary to be growing new F1 hybrids every year: They might be unstable you know... It's never been a problem for me. Corn has never produced any crop other than corn. Crops tend to resemble their parents. What's the old saying? The fruit doesn't fall far from the tree?

I may keep a crossing block, where any new things I am trialling and any odd plants from last year go that had interesting traits. Something really nice might show up in this patch and it might not. I keep this patch separated from the main patch by at least 100 feet. I might put it in a field in a different town, or I might grow it only periodically. I might do purposeful crosses in the patch. I usually just let them openly cross pollinate.

I grow my out-crossing landraces in patches by type: The small moschata squash, the large moschata squash, etc... If I grow 4 patches of the same out-crossing species I put them in the 4 corners of the field. This mostly keeps the smalls getting pollinated by smalls, etc... Then within each patch I select year by year for the phenotype that I am interested in.

With corn, I get adequate isolation if the patches are separated by about 20 feet from the next patch of corn. Most of the pollen for a patch comes from within the patch.

I also grow landraces in which I haven't segregated the population into multiple landraces: For example I only grow one landrace of carrots, beets, onions, swiss chard, and spinach. I plant the seed for these in blocks rather than in one long row. This allows the maximum intermingling of pollen.

The pepo squash, pumpkins, and gourds cause me the most worry, because they are all the same species, and there is so much variation between cultivars and so many distinct
cultivars, that it seems hard to maintain. This summer I grew pepo seed for the first time. We'll see how it goes.

With the out-crossers I want to maintain genetic diversity. I aim to collect seed from at least 50 plants from each landrace. With some crops like corn, I might collect seeds from 200 plants. I am actively breeding corn, I am not just maintaining it.

If an exciting plant shows up in a landrace, I am not adverse to splitting it off into it's own landrace, or even to turning it into a more traditional variety... For example this year I found a bush cantaloupe. That is exciting, because none of the parents had short internodes. I'll grow it in isolation next summer and weed out any plants that grow normally. There aughta be a market in suburbia for a cantaloupe with short vines.

I maintain a seed-bank of my varieties in two ways: 1- I make archive copies of my garden, and store the seed sealed inside steel cans in multiple off-site locations. 2- I send my seed out into the world as a living seed bank. It goes far away, and it stays close to home. Then if anything happens to my main stash, or my archive copies I might still be able to recover the essence of the landrace. That actually happened to me just this week. I misplaced the seeds from my hybrid swarm of non-muskmelon C. melo about a year ago. A lady I had forgotten sharing seed with grew it last summer, and is returning a sample to me. Wee Ha!

With both the inbreeders and the out-crossers, I add new genes from time to time when I find something promising. I might go wild about it and I might be conservative. For example with turnips I am very conservative. The only germplasm I add to my turnips has to carry the phenotype "Purple Top White Globe".

How do you maintain your landraces?

[robertb]

I'm trying much the same approach with outbreeders - Im not doing any inbreeder landraces at the moment - except that braod beans will cross pollinate from one end of the plot to the other. If I grow red-seeded beans at one end, and green-seeded beans at the other, I'm going to end up with all red beans.

[12540dumont]

Hi ya Joseph,
This is a very interesting topic for me. There are some things I do very differently than you.

For example, Although I grow all my cukes together and let them intermix and cross, I NEVER grow pickling cukes with slicing cukes. This is sort of a precautionary thing. Alan K. told me that he lost his Peace Cucumber because it accidentally crossed with a pickler, now all the Peace cukes are bitter. He's been working to bring the Peace Cuke back for several years.

I also set aside a few of the seeds in the bank that have never been crossed. Just in case something goes seriously wrong. Like the year the zukes crossed with the pumkins and I got a zucckin. Since both of these are very early in my garden, I was able to pull these out and begin again. Now I don't keep the two pepos together, but put them in a bed with moshatas and maximas.

Plots for hand breeding look different that plots I'm using to maintain a variety. For example in pole beans, they look like my bean trial, because I'm trying to keep these varieties separate until I figure out which ones are best for the farm.

In bush beans, where I'm looking for interesting new beans, I plant two rows of 40 seeds and then start another variety. In the area where two beans butt up together, I sometimes get crosses. Last year I got Rochambeau, so this year I will put it's mother on one side of it and it's father on the other and see what happens, because I'm curious.

Now, I only plant one vigna, because I'm trying to get enough of those fagiolinas that Cortona sent me (Trasimeno) to get into a soup mix.

I'll post up the melon trial so you can see what I do when I'm going to hand pollinate. When I'm actually going to try to keep the melons separate, I'll use Curtis Stowell's medium plot method. I'll post that up too.

For the new "big carrot" landrace, I'm doing just as Joseph would do, plant them in blocks, taste them and then replant the good 'uns. Carrots being biennial, they are easier to full around with. After I figure out the best ones, I'll let them cross and next year, do the same thing, pull them, taste them and replant. Ditto the onion trial.

Carrots get severe inbreeding depression, so I'm trying to get the most diversity I can into the first batch. I'll post that too. When I replant the carrots and onions, I'll put them in raised beds, wired against the gopher and I'll plant them fairly closely. When they flower, I'll rogue out anything that looks like it has CMS. After that, I will save the seed and just keep them well mixed and not worry about planting them by variety. So, in this particular instance, I'll finally have my own carrots seed in 2 years.

[Joseph Lofthouse]

Holly: Good info on the squash isolation scheme.

Taste is one of the criteria for my cucumber landrace. I wouldn't intentionally save seeds from a bitter cucumber whether it is a pickler (or as I call them a salad cuke) or a slicing cuke. That depends a lot on the weather, but I do what I can. If I got really clever about it, I'd taste fruits from each plant during the growing season and weed out any that even had a hint of bitter.

One of these years, I'm intending to taste every gourd in my garden. I tasted a few this year and they were sweet. But people tell me not to grow gourds because they are bitter and will ruin the other pepo crops by transferring pollen for the bitter trait to them. The easy solution to that is to only grow sweet tasting gourds. That would also give me a new and interesting summer squash crop.

[12540dumont]

Joseph, those Serpente di Sicilia gourds,
Lagenaria siceraria, don't cross with pepos. They grow so fast, you can hear them! They also bloom at night...now isn't that cool. When you're running buck naked through those evening summer fields, they'll be blooming sweetly

[steev]

Joseph's a Druid?! Bet there aren't many of those in Utah. Not prudent to do that on my farm, too much star thistle; worse than streaking thru a herd of ferrets.

[Joseph Lofthouse]

Jan 19, 2012 23:44:04 GMT -5 steev said:

Joseph's a Druid?! Bet there aren't many of those in Utah. Not prudent to do that on my farm, too much star thistle; worse than streaking thru a herd of ferrets.

I would feel honored if someone thought of me as a druid. My current philosophy towards growing and economics has been highly influenced by John Michael Greer, the Grand Archdruid of the Ancient Order of Druids in America thearchdruidreport.blogspot.com/

I love the ranch. It is so remote that don't see another human for months on end unless I brought them with me. And being too dry to support many insects, it makes sky-clad gardening trivial.

One of my favorite photos was taken out at the ranch while I was digging a water collection swale. In it I have the essentials for sky-clad swale construction: My boots, my hoe, and my dog.

[steev]

Now that I surely couldn't do on my farm. Not that I'd care about shocking passing traffic, but the air is so clear I'd not be able to get enough sun-block to keep the UV from being a real pain.

[Joseph Lofthouse]

My family were vikings. I hide from the mid-day summer sun. I garden in the morning, and in the evening. In the winter I grab mid-day sun whenever it is available. My health has been much better since I started getting sufficient sunlight. Even when it's 20F outside, if the sun is shining I'm skipping the coat and doing my errands in a wife-beater or less. Or if I'm in the village, I strip off my shirt and lean against the solar collectors on the south side of the house for a half hour at mid-day.

[davida]

Jan 20, 2012 2:35:34 GMT -5 Joseph Lofthouse said:

My health has been much better since I started getting sufficient sunlight.

We all need our vitamin D!

[nuts]

First what I'm expecting from a landrace.

I expect it to be a genetic divers population with the potential to improve.
For me that implies that the plants must be able to cross.
A landrace that's constituted of a mix of inbreeding lines doesn't make sense to me,because improvement can only be achieved by new genetic recombinations,

New genetics can only be achieved by crossing.
For practical reasons I want these crosses occur naturally allthough in theory it's possible to constitute a landrace by manuel crossing.

I see it as opposite to the method of intentional crossing,followed by a few generations of inbreeding to stabilize the desired traits.In this case the resulting variety will have lost much of its (or it's? genetic diversity and selection won't have much impact,unless you proceed to a new cross.

comparing the two methods:

crossing individuals versus mixing populations.
fast stabilisition of desired traits versus slow stabilisation of disired traits.
choosen crosses versus random crossing.
high technicity versus low technicity.
low initial population size versus high initial population size
resulting in low genetic diversity(low adaptability) versus high genetic diversity(high adaptability).

key points in constituting a landrace are rate of crossing and population size.

Easy candidates are plants that have naturally high rate off crosspollinisation,like carrots,onions,brassicas,corn,cucurbits
In fact most of the varieties(except commercial hybrides) from these crops can be considered in some way as landraces.because they come from random crosses within a population of a certain size,resulting in a certain genetic diversity.

More problematic are the crops that are self pollinating with low or zero rates of crosspolinisation.
like tomatoes, beans,wheat.

I don't know how much natural crosspolinisations I can expect for tomatoes.,in my conditions,depending on the local insectpopulation and the ability of the flowers to take profit of these insects.
I'd like to find it out.
I'm hoping to receive seeds of josephs mainseason tomatoe landrace,counting on a genetic diverse population,and even hoping some natural crosses being in his mix.
I'll plant a maximum number of plants of these interplanted with very diffferent varieties,like white black or very small toms.
Not that I want to breed fancy varieties but I see the fruit more as "marker" to spot natural crosses.I'd like to improve the ability of interbreeding of tomatoes.Any natural cross is interesting for me.
I suspect that the breeding of tomatoes in some way favored self polinisation and the ability to naturally cross may have been lost to some degree over the ages.

So do I expect the rate of crosspollinisation for wheat much higher in landraces than in the extreme inbred modern varieties.
For tomatoes it would be interesting to know which varieties have higher rates of natural crosses.

I'm busy with the astronomy domine sweet corn ,I grew for two years now.I don't do any selecrtion for color or taste I just choose the about 50 minimum best ears,well developped and well filled.That's the only thing I plan to do for a few years and see what happens.
Years of blending genes,like stirring the soup.How much wil it stabilize(size and color and such).
A way to speed up the blending process could be sowing double amount and detasseling the half off it,and harvesting only the detasseled plants ffor seed.Eliminating the self pollinisation.Thinking of it.

My fava bean landrace I started five years ago with beans from the moroccan store with aquadulce,valencia,d'auvergne,witkeim mixed in later There are acidently crosses with feveroles(small fava bean) in too.This year I don't have anything new in it,but next year I plan to ask Dumont for some beans.
Favas are well visited by bumble bees,and I thinka good rate of crosspolinisations is to expect.Not sure if all varieties are good crosspolinisators though.
I Imagine a risk when you mix in a selfpolinator and you like this bean and you select for it during years.You will end up with only this new variety,and your genetic diversity is washed down the drain.

My vision of landrace is maybe not exactly the same as all of us.(but it's close to wikipedia )
A landrace is a variety,traditionally present in a region for long time,that never went trough the bottleneck of modern plantbreeding, with allways a sufficient big populationsize to maintain a good genetic diversity.
What we are talking more about is about creating new landraces,by mixing many genetic origins in one population to create something new.You take two packets of seed and you put them in one packet,for me you don't have a landrace(yet ;D)
I think you must have some blending of genes before you can call it an embryo of a landrace.

ok don't mind me, I do enough reading on this board to know what you're talking about when you talking about landrace.

[raymondo]

I am only just beginning this mass crossing idea with green-fleshed melons. I only have a single fruit this year so selection is easy! My intention is to grow this mix on on side of the house and a single variety for trial on the other side. This should keep crossing between the two patches down to a minimum.
I'm a bit further along with my collard mix being into the third year of the red-glossy mix and have added more (collard/savoy cabbage/tuscan kale/red cabbage mix)) to this year's grow out. I grow out a good sized patch. Plants that taste good, are less insect damaged, or are otherwise interesting get lifted and put together to flower. The rest get either eaten or composted.

Nuts, regarding tomatoes, you could set up a collection that is more prone to outcrossing by growing only varieties that have exposed stigmas (exserted in botanical parlance if they really protrude). A number of potato leaf and beefsteak varieties have exposed stigmas. I believe that currant tomatoes also exhibit this trait. It would be a matter of growing out as many varieties as possible, looking for the trait, and adding that variety to the embryonic landrace. I know at least one variety that often exhibits this - Paul Robeson. I'm sure there are many others.

[Joseph Lofthouse]

Supposing that there is a landrace of plants with 0% possibility of crossing. For example, a landrace of garlic consisting of 60 allegedly different varieties. That kind of landrace still makes sense to me, and still gives the opportunity for improvement and for adaptation to my garden, because the plants that produce best for me will end up being those plants that predominate in the landrace. I'll likely maintain varieties that do better in wet years along side varieties that do better in dry years.

But garlic is a very rare crop. Most inbreeders have some small percentage of cross pollination going on.

I think that tomatoes natural pollinators got left behind when tomatoes were removed from their endemic region. So they turned more to self-pollination. The cross pollination rate for modern tomato cultivars is around 5%, so if you grow 20 plants you can expect one of them to be a cross. In my crop where I grow around 400 tomato plants per year I can expect around 20 of them to be F1 hybrids, in addition I can expect to be growing some percentage of F2, and F3 etc segregating crosses. There's no way to model that mathematically, since the crosses that I am selecting from might be more or less likely to be selected as part of the landrace, but 5% additional per generation seems resonable, so I might could expect around 15% of the crop each year to be an unstable segregating plant, so around 60 new tomato varieties per year showing up in my garden.

Some tomatoes (those with the stigma exposed) have a higher cross pollination rate. This trait is more common in the potato leaved varieties.

The cross pollination rate of wheat is up to 9% in dry years.

If I combine 20 inbred lines into a singe gene-pool, there is the possibility for great genetic diversity. There is also the possibility for very little genetic diversity... It depends on the nature of the inbreds and how closely related they are to each other. If the 20 lines are modern inbred sweet corn that all came out of two or three plant breeding programs then there will be little possibility for improvement since they are all essentially clones of each other. I like using elite germplasm from modern plant breeding programs, and combining it with wild genes. That provides plenty of opportunity for diversity and selection while at the same time taking advantage of the agronomic advances of recent decades. I sure like descendants of the Iowa Stiff Stalk Synthetic for example.

I garden in a location that is an extreme outlier: Right at the ecological limit for many species. So local adaptation is very quick in my garden. After 1-3 years a new landrace is very well suited to my garden.

I don't see much difference in stabilization rates between cross pollinating landraces and inbreeding landraces: the adaptation/selection in the first year or two is remarkable. By the third year the harvest seems magical regardless of whether it's crossers or inbreeders.

I don't worry about the rate of crossing in landraces. Even with 0% crossing, landraces are really clever to grow.

To me, in order to call something a landrace it needs more genetic diversity than is typically found in heirlooms or modern open pollinated seeds. Heirloom varieties often originated from a single seed. That's not much diversity to work with. So called open pollinated varieties are often highly inbred before being allowed to "openly pollinate" in a greatly reduced genepool. Many tomatoes that are called open pollinated for example are actually highly inbred.

I've grown several hundred varieties of tomatoes so there are lots of possibilities for diversity in my crop. I might only select 50 main season plants per year as parents for the next generation, but because I plant 1 year old, 2 year old, and 3 year old seed, there might be as many as 150 varieties represented in any given year, plus the 60 plants that could be expected to be segregating nets me the possibility of around 200 varieties in the mainseason tomato landrace. In addition, it's very possible for varieties to switch between landraces from year to year, so an early season tomato, or an odd-ball tomato, might end up in the main season landrace.

In today's extreme inbred wheat, we can expect the same cross pollination rate as with other wheat (up to 9% in a dry year), but since each plant is essentially a clone of every other plant the effective cross pollination rate is 0%, unless many different varieties are inter-planted.

[littleminnie]

Joseph I will need some mentoring as I contemplate starting a melon landrace and I have sort of started a moschata one.

[12540dumont]

Joseph,
Can you talk to me a little about your selection process.

For example, this is a Scarlet Ohno Turnip from NZ.

As you can see, some of the plants are vigorous, some a little less so. It was my plan to save the best of these, and then save the best of all the turnips that I received this season:
Eastham Turnip MacComber
Golden Globe
Noir Long de Paradihan
Boule d' Or
Marteau
and Joseph's Purple

And then transplant them all in one bed and let them have a go at increasing the genetic diversity.

Then I mix up the seeds?
Keep them in separate piles to replant in rows?
Keep only those from one variety and reselect the best of those?

If I keep selecting for diversity, I keep them all.
If I select for only the vigorous, I might end up with just Joseph's Purple.

Arghh..

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