Landracing lettuce - promiscuous pollination potential?

[templeton]

I like lettuce - mostly looseleafs. I've got a lot of legacy lettuce seed from older Morton's stock. Oakleafs self seed in my garden, along with the occasional red cos.
I seem to recall (Deppe?) that lettuces self-pollinate as the stigma emerges from the flower.
Has anyone looked into landracing lettuce?
I have very limited growout land - 5-6 sq metres is probably all i can afford in the initial stages.

Any suggestions how i might proceed - has anyone thought about this much?
I'm looking for bolt resistance, heat resistance, but I am a bit scared hat due to my slack approach by letting everything self seed that I might be inadvertently drifting toward early seeding.
T

[reed]

I also like lettuce and have quite a few kinds although I couldn't put a name to any of them. I have just let them grow and self seed for awhile and they have self selected to half a dozen or so loose leaf kinds of reds and greens. Don't know if any actual crossing has occurred or not.

I have been selecting for cold hardiness and year before last had some overwinter so most of my saved seed is from them. Only a single plant made it through this year. I don't mind early seeding cause I think the volunteers are good even in hot weather if harvested very young.

[oxbowfarm]

I think you will find you will get reasonable crossing rates with different varieties planted in a mixed block planting as long as you have sufficient small pollinators in your local ecology. Lettuces are largely selfing, similar to the polyploid brassicas, but they DO cross naturally without having to do all the hoop jumping and washing the stigmas etc. The bees can do it for you as long as the flowers are all adjacent to each other.

With my mustard breeding projects, I've found that even when I plant two different varieties right next to each other at isolated sites, probably 80-90% of the seed from each plant is selfed. But 10% crossed seed per plant ends up being a HUGE number of F1 offspring anyway with a crops like these that produce so many flowers and so much seed per plant.

For a low stress landrace project I'd just mix all my seed I wanted in my lettuce landrace and let it bolt as a block.

[billw]

Yeah, I get lots of crossing from lettuce. I started with a wide mix of leaf lettuces and I don't really do any selection other than non-bolting, since it is just for our personal use. After seven years, I can still see some recognizable varieties, like Little Gem, which was overrepresented in what I started with, but I also get lots of new and different phenotypes.

[richardw]

I found it interesting that many of you guys say you get crossing in your lettuce, i must have about 10 different varieties that have been volunteering for at least last 10 - 15 years yet they come up looking the same every year, i get no crossing whats so ever.

[ferdzy]

We let our lettuce go to seed and self seed, but we have not seen too much crossing. Some. But things are still pretty distinct.

One thing we do, if we have time, is once they start to bolt; go around and pull out the first half to go of any one type. Then the ones that go to seed should be the ones that "hold" longer than average. Either that or they were the runts that were slow to get going, LOL. (Actually I try to pull those too. Larger lettuces, slower to bolt are the ones I try to leave. But we don't get too scientific about it.)

[rowan]

As far as I am aware lettuce selfs before the flowers open which is why I am surprised at reports of crossing. I have certainly not had any crossing, but then I don't grow much lettuce.

[billw]

Lettuce often pollinates before the flowers open, but the stigmas are still receptive for a day or so after opening. I see a lot of cross pollination in self-pollinating species that open their flowers before they become unreceptive. I suspect that temperature, humidity, and of course pollinator populations play a role. Pollen tends to be less mobile at colder temperatures and higher humidities and I have both. I also have very high levels of native pollinators. Flowers might be less likely to self-pollinate under those conditions, allowing the insects more opportunity.

[richardw]

Yet my summer climate is often dominated by very warm dry foehn winds along with high numbers of both native/non-native pollinators and wide range of flies species, The self sown plants are bamboo staked side by side along the sides of the pathways

[templeton]

Thanks for all the input.
Mostly I get my original Royal Oakleaf self seeding. I do let everything else go to seed - they are scattered across my small garden, so while not next to each other, usually only separated by a few metres. And i plant haphazardly - wherever there is a spot to shove a lettuce in, and i don't keep good track. I'm encouraged by your reports of some crossing. But I think like Rowan and Richard, I don't get much (any) crossing. Perhaps its a bit too dry and hot here rather than like Bill's location. Pollen mobility -hmmm. I doubt it is a lack of pollinators - My place is crawling with insect diversity. Re-sowing seeded morton's mixes its a bit difficult to keep track of what was originally there. Damn, probably have to take more notes.
T

[Joseph Lofthouse]

Wild lettuce is one of the most prolific weeds in my garden. If I let domestic lettuce go to seed in my garden, then the next year, a few of the wild lettuces will have a phenotype mid-way between wild and domestic. So while crossing seems rare to me, It seems like there would be plenty of opportunity for some degree of cross pollination, especially if varieties were closely inter-planted.

[walt]

Wild lettuce here is perennial.  And I've never known it to cross with domestic lettuce.  If it did, I'd look for seeds on it and see if I could get a perennial lettuce that doesn't get bitter so soon.
Is your wild lettuce a wild species, or domestic that reverted to wild?

[Joseph Lofthouse]

Mar 12, 2018 12:58:08 GMT -5 walt said:

Is your wild lettuce a wild species, or domestic that reverted to wild?

I don't know... My fields have been in production for about 150 years... To me, what I call wild-lettuce has little resemblance to anything that I have seen cultivated. So I'm definitely leaning towards undomesticated rather than escaped/feral. It sometimes germinates in the fall, and overwinters as small plants. I keep trying to collect seeds in the fall of some of the suspected hybrids. I at least put flags on some of them during the growing season. But I don't get them planted out the next spring...

[richardw]

William Is this Lactuca serriola, lots of it around here

[richardw]

I had a large area of it that i pulled out during the summer, those spines on the underside of the leaf caused a nasty rash down both arms. Got lots of it around here and like you guys its a introduced species here also. But haven't seen any sign of it crossing with the domestic lettuce though.