Author Topic: Promiscously pollinated french beans (phaseolus vulgaris)  (Read 586 times)

Nicollas

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I'm back on the dwarf outcrossed bean again, so i copy here the thread i've created on HG, hoping to bring more people in it. (and now i use the trending "promiscous" term  ;) )

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Hey folks, i want to share with you an exciting project that i’m thinking about. I will not be able to work on it in the foreseeable future so i though it will be more useful to present the plan than the results as you clever and skilled gardeners could start doing stuff with that.

Start of the project is a bean mutant that is dwarf and with a much more outcrossing rate than usual beans. It comes from a single recessive gene termed do (=dwarf outcrossing).

In the studies, the natural rate of cross pollination was 10 - 56% :) The higher cross pollination is due to a “delayed anther dehiscence”, so that means the flowers opens but pollen has not yet been released on the stigma, whichs leads to opportunity of a pollinator to first pollinate the flower. So this not the same mechanism as P. coccineus or any sterility so the pod set should be very good anyway (the stigma will be covered by the flower’s pollen anyway)
The hand pollination of do/do plants without emasculation in the morning gives very good percentage of cross pollinations too.

So now the bad part, the dwarfing. I dont remember if the gene control the two traits or if it is just strongly linked. Dwarfness is due the shorter internodes, smaller leaves, and maybe slower growth. I remember reading that combination of do/do plants with the bush type gives plants that can’t compete with normal bush types, so maybe this trait is only useful keeping in vining or semi vining types.
The good side is that it acts as a precicious marker for plants homozygous for the do variation.


(do type is on the right)

So from here i can see two options :

  • Landracing beans, the Lofthouse way, keeping a lot of dynamic genetic pool of do/do individuals. Maybe the best solution is to keep a patch specifficaly for introduction of regular plants to intercross wih a part of the landrace to then segregates for do/do plants to bring back to the landrace ? Managing do/do and +/do plants together could be tricky as +/do may outcompete the others ?
  • Using do/do plants as proxy to mix a lot of genetic from regular plants and then selecting only +/+ to breed new cultivars easily (either by passive pollination, or by hand pollination - very high percent of takes without emasculation making it possible). What is cool with this project is that one can select do/do plants closer to good agronomic cultivars at each stage so you end up mixing directly two good genomes and select from thant. One can even imagine creating near isogenic lines of some favorite cultivars (variating only at the do locust) to makea lot of hydrids with this cultivar.

So where to obtain the germplasm ? Here it is : https://npgsweb.ars-grin.gov/gringlobal/accessiondetail?id=1478595
Please check that the plant looks like dwarfed, because by def this could have been crossed and selected for the wild type


I uploaded the docs here : https://drive.google.com/drive/folders/1A8gNYc8hiMMR12X1K7NHlAHUgvmMTKru?usp=sharing
I dumped one of the doc into multiple images because i had issues viewing it.
« Last Edit: 2021-05-31, 11:36:38 PM by Nicollas »

Garrett Schantz

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Re: Promiscously pollinated french beans (phaseolus vulgaris)
« Reply #1 on: 2021-05-31, 11:41:33 PM »
I have read about this gamma ray mutant bean before.

Could save some trouble in attempting hybrids with other species as well.

I prefer pole beans though, so the dwarf characteristic might be a downside to me. Others here prefer bush types as they mature faster.



I have been thinking of trying to introduce the promiscuous mechanism from P. coccineus to P. vulgaris. I would need to isolate the hybrids in pots to do that though, crossing with another vulgaris would smother the trait.

Nicollas

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Re: Promiscously pollinated french beans (phaseolus vulgaris)
« Reply #2 on: 2021-05-31, 11:56:29 PM »
There may be another gene that could counter the dwarfism, if it is only caused by shorter internodes ?

(Edit: i have no time to watch for this now, but : Li (L) longvs. lishortinternodes(Lamprecht 1947b; Norton 1915))
« Last Edit: 2021-06-01, 12:12:12 AM by Nicollas »

Nicollas

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Re: Promiscously pollinated french beans (phaseolus vulgaris)
« Reply #3 on: 2021-05-31, 11:58:12 PM »
The bonus from the do gene is that the plant will self pollinate eventually if no foreign pollen come first (kinda like fava bean ?). I've read that a bunch of people have problem with coccineus pod set if conditions or insects are not in the good range.

reed

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Re: Promiscously pollinated french beans (phaseolus vulgaris)
« Reply #4 on: 2021-06-01, 04:14:12 AM »
I've found that the rate of crossing in phaseolus vulgaris is sometimes actually quite high. I have a lot of bumblebees and all I have to do is intermix my planting, making sure that varieties are immediately adjacent to a different variety in the patch.

I also prefer pole beans because in my climate it is hard to mature nice seed from bush beans, let alone get a good harvest of dry beans. On the other hand I've grown tired of building all those trellises for the large vined pole types.

I don't know that it is related to dwarfism but a few years ago I found some that have a "semi" pole growth habit. They definitely climb but only to five or so feet. Many also have a branching habit, often growing new shoots from the base after the initial growth has already produced. I have noticed the internodes are closer together on some of those so maybe this dwarf gene is involved in pole types as well.  Also in my favor they seem to be even more prone to easy crossing.

Diane Whitehead

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Re: Promiscously pollinated french beans (phaseolus vulgaris)
« Reply #5 on: 2021-06-01, 07:45:26 PM »
Yes, I have grown them.  Interesting but not very tasty.

They are what Native Seeds Search calls "semi-pole"
Victoria, British Columbia, Canada
cool mediterranean climate  warm dry summers, mild wet winters,  70 cm rain,   sandy soil

reed

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Re: Promiscously pollinated french beans (phaseolus vulgaris)
« Reply #6 on: 2021-06-02, 04:29:54 AM »
Yes, I have grown them.  Interesting but not very tasty.

They are what Native Seeds Search calls "semi-pole"

Yea, that's what I call them too. There are lots of kinds and more show up by segregation all the time. Do you mean not very tasty as green or snap beans? I grow them mostly for dry beans and they are fine that way. One that I started with called Refugee is also a nice snap bean.

So far I have only isolated one, a descendant of Refugee for snaps and it rivals my old favorite KY Wonder for that. Several new ones showed up last year from that same grex but I will only be able to increase seed for them this year as probably won't be enough to sample as green beans.

To increase crossing I grow them all mixed up so if you pick some to try for green beans it is hard to even tell which vine they are coming from, impossible almost, to be sure what I pick even all came from the same vine. Still I have 1/2 a dozen more this year planted in mostly consistent patches so we can easily test them out as snaps.

Diane Whitehead

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Re: Promiscously pollinated french beans (phaseolus vulgaris)
« Reply #7 on: 2021-06-02, 09:55:59 AM »
I eat beans only as snaps. 

I made a mistake on the term Native Seeds Search uses, and I have seeds of only one.  The others from them are either bush or pole.

Here is the description on the packet:

Sonoran Canario:  Elongated beige early-maturing open bushy-pole bean.  Lilac flowers.  Collected from coastal plains of Sonora.
Victoria, British Columbia, Canada
cool mediterranean climate  warm dry summers, mild wet winters,  70 cm rain,   sandy soil

reed

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Re: Promiscously pollinated french beans (phaseolus vulgaris)
« Reply #8 on: 2021-08-30, 03:43:18 AM »
I've had a bunch of new off types show up in my semi-runner beans this year. I didn't plant any black seed seeds but have three different types of black seeds. Different in pod configuration, seed size and shape, one had purple pods.

Also a new kind of greasy bean, don't know where they came from as my other greasy beans are large pole types and have not been grown in close association to my semi-runner project. There are four kinds, white, solid brown, brown speckled and tan with brown frosted edge. All have the same small three to four inch pods tightly packed with lots of smallish round seeds. They all also have a bit of a tendency to shatter open if left on the vine too long, all are very very productive of dry beans.

A problem I'm encountering in my semi-runner bean mix is quite a bit of bush and large vine types are showing up from seeds harvested off semi-runners the year before. The bush ones are easy to cull out but the vining ones are mixed up on the trellises and harder to separate from the rest.