Landrace

[grunt]

I think Permelon would fall into the landrace category.

[honeydew]

Out of curiousity - what is Permelon?

[remy]

My understanding of landrace is this. If say separate populations of people grow the same variety for long enough, that variety will become distinct in each location. A good example of this is the scarlet runner bean. I discussed this with an old Tuscarora man. They've been growing it for a long time and selecting out the best beans off the best plants for their location. (With another variety of bean he gave me, he told me to only save the dark beans for planting, so in away I suppose that is how landraces happen.) He said that he can tell the difference between the Tuscarora version and the generally known one. Another person I know has another a version from Asia. This one had seed saved from plants that were hear tolerant. So the Asian variety performs well in locations where Scarlet Runner Bean normally does not. Now both versions of the Scarlet Runner Bean look very similar to the common version grown by most gardeners, but you can tell they are not the same. You can tell by the variations in the bean seed shape/color/size, and how the plants grow. I would suppose that if you keep the genetics separate for long enough, you would see really major differences.
So in essence no cross breeding is done to create a new variety with a land race. It is through isolation of genes(though gene mixing with another variety within that population is possible) and saving seeds that show a stronger expression of certain genes.
Remy

[Alan]

Nov 30, 2010 12:33:59 GMT -5 remy said:

My understanding of landrace is this. If say separate populations of people grow the same variety for long enough, that variety will become distinct in each location. A good example of this is the scarlet runner bean. I discussed this with an old Tuscarora man. They've been growing it for a long time and selecting out the best beans off the best plants for their location. (With another variety of bean he gave me, he told me to only save the dark beans for planting, so in away I suppose that is how landraces happen.) He said that he can tell the difference between the Tuscarora version and the generally know one. Another person I know has another a version from Asia. This one had seed saved from plants that were hear tolerant. So the Asian variety performs well in locations where Scarlet Runner Bean normally does not. Now both versions of the Scarlet Runner Bean look very similar to the common version grown by most gardeners, but you can tell they are not the same. You can tell by the variations in the bean seed shape/color/size, and how the plants grow. I would suppose that if you keep the genetics separate for long enough, you would see really major differences.
So in essence no cross breeding is done to create a new variety with a land race. It is through isolation of genes(though gene mixing with another variety within that population is possible) and saving seeds that show a stronger expression of certain genes.
Remy

Remy, I agree this too can be considered a landrace definition as well as others stated above.

The only reason I incorporate the definition to include phenotypic diversity is because many examples of landraces are genetically diverse, particularly when talking about accessions of grains from the middle east as well as seed accessions gathered from Native American sources.

I think we are running into the same definition issue people have with "heirloom" seeds.

In regard to the word landrace as used on my blog and in my breeding project, my stated definition listed previously here is the intended meaning of such.

[grunt]

Permelon is a West Virginia product, that I have never seen in any seed catalogue. I managed to track some seed down through a food blog posting. I am not impressed with the vigor or productivity, but that may be because of climate differences = we don't have warm nights or humid conditions.

[ottawagardener]

That sounds to be about what my understanding of landrace was. Funnily enough, well you were all discussing this, I was reading a textbook on Plant Propagation (for fun as one does) and ran across this definition. Keep in mind that I believe the definition of words is always in flux and is based on usage with regional/cultural/etc. differences in definitions common but for no good reason at all, other than to add to the conversation, here's what they say:

** Official Voice: Chapter 5, page 146 **

Historically, farmers throughout the world have maintained seed-propagated plants by saving selected portions of the crop to be used to produce the next cycle. These populations, called landraces, evolved along with human societies and are still found in some parts of the world. These poulations are variable but identifiable and have local names. This practice results in genetic populations adpated to a localized environment. Their inherent variablility provides a buffer against environmental catastrophe and preserves a great deal of genetic diversity.

** So sayeth Hartman and Kester's Plant Propagation **


As for Permelons, I vaguely remember hearing about those before but never felt the urge to try. We do have warm temperatures but not really humid like they have south of us in the ag regions of Essex county where I used to live. Those were sticky summers.

[keen101 (Biolumo / Andrew B.)]

Yeah. To me a landrace is a mix of as many genetically diverse plants as possible. And adapted to as many diverse conditions as possible. Of course over time in many cases the landrace will become adapted to the specific region, and will no longer be a landrace. But for certain traits it still may carry more genetic diversity than some very inbred heirloom varieties.

I think there are two main advantages for creating a landrace:

1. The first is that yes, it can become a buffer for any kinds of changes. whether those changes are a new pests, different climate, different nutrients in the soil, or different toxins introduced, etc.

2. The second is that it can potentially be a useful tool for finding a new variety to adapt to conditions that many standard varieties would not thrive in. Next spring i will be attempting to test this theory by throwing as many different watermelon seeds together, and planting them in my yard. I've always had a hard time growing watermelon here at all. I'm hoping that i will get at least one variety that does "normal".

Perhaps the only way to get such a variety is by letting all the available genetics to cross with one another. One might have good genes for growing good roots, but not good at growing fruit. Another might have good genes for growing fruit, but may not have good genes for pest resistance. In a way it will be a survival of the fittest, but with the best chances available.

[DarJones]

A landrace specifically means a geographically (or regionally if you prefer) adapted variety that has been grown in an area over a period of time with proven performance in that specific area. There is nothing in the term that specifies the landrace is pure breeding, only that it is adapted to the region from which it derives.

As an example, there is a sorghum variety grown here in the southeast that has been grown over so many years and has become so well adapted that it is referred to as a landrace. It is grown to produce sorghum syrup. I can name several locally grown landraces of watermelon, citron, melon, cowpea, etc.

DarJones

[Leenstar]

Without an influx of new genetic material, wouldn't selective pressures eventually reduce the overall genetic pool?

What steps do those of you working on "landraces" use to ensure the genetic diversity? Is there active inclusion of new plants to the mix? Is it open pollenation versus plant separation techniques used to preserve certain cultivars?

I am interested in selecting for things in my own backyard garden that will perform well here.

Thanks for the education!

[Joseph Lofthouse]

Jan 1, 2011 13:45:07 GMT -5 Leenstar said:

Without an influx of new genetic material, wouldn't slective pressures eventually reduce the overall genetic pool?

My landraces are constantly loosing genes by selection, and constantly gaining genes by influx. I'm hoping that I am mostly gaining desirable genes and loosing undesirable genes. I typically plant any new varieties in the next row over from my landrace. If they do really well the seed gets incorporated into the land-race. If they do much worse than the landrace then only the pollen may be incorporated. I plant less than 15% of new varieties in a year so that I don't swamp the existing genetics with new material.

Jan 1, 2011 13:45:07 GMT -5 Leenstar said:

What steps do those of you working on "landraces" use to ensure the genetic diversity? Is there active inclusion of new plants to the mix? Is it open pollenation versus plant separation techniques used to preserve certain cultivars?

My strategy is:

Start with a diverse gene pool. I often include 10 to 60 varieties when starting a new land race, but I can be happy with as few as 3 to 5.

Plant some 2 year old seed and some 3 year old seed so that I avoid loosing desirable traits just cause I had one unusual growing season.

Swap seeds with the neighbors that are growing my same species. Include some commercial varieties if I like.

When collecting seeds I save a few seeds from many plants, and a lot of seeds from the best producing plants. Also when collecting seeds I save from a variety of fruit-types, colors, plant types, etc..

Basically I end up growing two land-races... Joseph's Best contains the most productive plants, the best tasting, etc. Joseph's Diverse contains everything else... The Best will occupy 80% of my field space, and the Diverse will make up the rest. Never can tell when something really clever will show up in the Diverse plot.

I do not try to preserve pure cultivars... Though I might have many sub-varieties, I do not worry about rigorous isolation... Pollination is basically quadratic in nature: things tend to be pollinated by other things that are very close to them. (A plant is 100 times more likely to be pollinated by a plant a foot from it than by a plant 10 feet from it.)

So I grow my different colors of corn in blocks to themselves, but only separated by a row of squash. They mostly breed pure.

[robertb]

If a landrace is defined as a local or regional variety, then an artificially created mix isn't going to be a 'true' landrace until sufficient generations have passed for the genepool to develop 'local' characteristics. A good example might be British bees; we haven't got the large-scale queen raising industry you have in the States, and most queens are raised locally. When I tried bees from a different part of the UK, they didn't flourish at all.

I'm now using local hybrids, descended from swarms I've collected in the area. Most of the genetics are probably native, but there were large-scale imports of mostly Southern European bees last century, and this is still continuing. The result is badly adapted bees which can't survive our winters without beekeeper assistance, and often won't mate in bad summers. The first few generations of hybrids are often bad-tempered as well. Obviously, these characteristics soon get selected out. The result is a bee that often looks rather yellow, but generally acts like a native bee, survives weather which is often marginal for the species (we're near the edge of the honeybee's range here) and which can get reasonable quantities of honey in most summers.

[Joseph Lofthouse]

Jan 13, 2011 5:30:06 GMT -5 robertb said:

If a landrace is defined as a local or regional variety, then an artificially created mix isn't going to be a 'true' landrace until sufficient generations have passed for the genepool to develop 'local' characteristics. A good example might be British bees; we haven't got the large-scale queen raising industry you have in the States, and most queens are raised locally. When I tried bees from a different part of the UK, they didn't flourish at all.

In my experience with plants... That selection for thriving locally happens in the first generation. For example over the last couple years I planted around 60 varieties of cantaloupe as part of my landrace cantaloupe breeding program. Some varieties didn't even germinate in my soil. Some varieties got ate by bugs before true leaves appeared. Some varieties grew but didn't set fruit. Some varieties grew and barely set fruit. And a few individual plants thrived, vigorously out producing the rest: As much as 5 times more leaves/fruit than a typical plant, and weeks earlier.

The same thing happens with carrots, or turnips.... If I plant 1000 plants, then select out 20 or so for seed that grew the best in my garden, then in one generation I have pretty much taken care of the local adaptability issue. That's why I like to start with lots of variety. It makes it easier to discern which grow best in my garden.


Here's a 13 page review of the scientific literature for how the term landrace has been used:
www.semencespaysannes.org/bdf/docs/landracereview-euphytica1998.pdf

My favorite sentence in the review is this, "Yield stability of
landraces under traditional low input agricultural sys-
tems is due to the fact that whatever the varying biotic
and abiotic stress for each plant one or more genotypes
within the landrace population will yield satisfactorily.
Landraces were and still are grown by farmers, market
and private gardeners all over the world for this reason."

And my second favorite sentence:
"‘In general, landraces have de-
veloped at low levels of cultivation, fertilization (i.e.
inputs such as artificial fertilizers, ACZ), and plant
protection; they are subject to selection pressures for
handiness and dependability rather than for produc-
tivity.’"

A new term to me that was mentioned in the paper is "landrace group". It seems to me that Astronomy Domine sweet corn has now become a landrace group, since there is the Bishop strain, and the Ozark strain, and the Mendon strain, and the New York strain, and the Pakistan strain, etc... Implicit in the idea of "landrace group" is the idea that landrace crops travel from place to place and that they are traded among farmers both in one area, and between different areas.

The conclusion of the paper is this:
"Maybe, Mansholt’s (1909) amended definition is still the best:
an autochthonous [locally adapted]
landrace is a variety with a high capacity to tolerate
biotic and abiotic stress resulting in a high yield sta-
bility and an intermediate yield level under a low input
agricultural system."

[robertb]

You might get rid of the odd simple dominant in the first generation, but in most cases, those genes will still be there. Over several generations, you'll get fewer and fewer of the ill-adapted types. To take my bees again, I picked up two swarms last year. Both are probably stock which has been in the UK for some time, as not many queens are imported these days. Yesterday I gave them their annual oxalic acid treatment for mites.

One has a small cluster, covering five seams (the gaps between combs). It's very quiet, not flying at all in temperatures around 10-11 degrees. A colony like that won't eat too much over winter, and is likely to come through well with little or no support from the beekeeper once it's got tjhrough its first winter and established itself. The other was flying quite strongly, with a huge cluster occupying the whole box. That one will eat far more, need a lot of support, and is far less adapted to the local winters. I'm going to requeen it, but it's far from the first like that I've come across, and it shows that it takes time to build an adapted strain out of the sort of mess British beekeeping's got itself into.

[Joseph Lofthouse]

Good work on the bees. It takes a lot of dedication and care to keep a thriving population of honeybees.

Jan 14, 2011 8:53:20 GMT -5 robertb said:

You might get rid of the odd simple dominant in the first generation, but in most cases, those genes will still be there. Over several generations, you'll get fewer and fewer of the ill-adapted types.

One of the joys of a land-race is that the genes are mostly still there. In wet years the wet adapted plants produce much of the crop. In dry years the dry adapted plants produce much of the crop. Etc...

I figure alleles are complicated... There are alleles for dealing with my soil, and my bugs, and my high altitude sunlight, and my temperatures, and my mammals, etc... It takes hundreds or thousands of genes to determine how a specific plant grows in my garden.

In my garden, with plants, the adaptation to my garden can be extraordinary in the first year, especially if I start out with 50 varieties, it becomes instantly obvious which ones are best for my garden. It's easier with plants than with insects, because I can easily plant a thousand seeds, or 100 different varieties of corn.
It's much harder to trial 1000 queen bees. If I loose a corn plant it's no big deal... If I loose a queen it's traumatic.

[blueadzuki]

Jan 14, 2011 13:32:13 GMT -5 Joseph Lofthouse said:

One of the joys of a land-race is that the genes are mostly still there. In wet years the wet adapted plants produce much of the crop. In dry years the dry adapted plants produce much of the crop. Etc...

That's true, provided you make a point of making sure at least some seed from every plant that makes it gets into you planting each year. If on the other hand you only take seed from the best and brightest each year the gene pool can get skewed really quickly (this is particualry true if the crop you are dealing with is largely self pollinated) if you get the same climate for several years running (but not forever). Lets say that you happen to get unususally dry seasons, for seven or eight years. Obviously those plants that are well adapted for dry seasons will likey produce more than those that aren't. If you make a point of taking some seed from all plants that survive both dry lovers and wet lovers will be somewhere in the population (dry lovers will be more prevalent but there will be some of everythig. If however you only save seed from those plants that did spectacularly, you basically only taking seed from drylovers; do that seven of eight years, and you very well may have a population of only dry lovers after a while, and if the next season brings a season long deluge you may very well suffer total crop loss (unless you are lucky enough to have some plants that turn out to just be simply "stronger" than normal (better able to tolerate both drought and flooding). I have meny times mentioned the story of the Indian woman who made a point of saving seed from even her worst producing corn on the grounds that trying to make the crop better would be an insult to the god who gave man corn in the first place. I may feel this to be extreme but leaving at least a little of the "less great" in the population is probably a prudent idea.