Phaseolus vulgaris group wide crosses

[andyb]

Interesting, Reed.

In that older thread, Breeding Beans, Jim mentioned that crosses between the two races of common beans often (always?) have problems with the initial root dying that you could get around by germinating the bean and then chopping the root off shortly after it started growing. Adventitious roots would develop that don't have the same genetic problem.

A few weeks ago, I gave the surgery a try with some uncrossed Tiger Eye beans I had laying around and it worked surprisingly well. I used a germination-test setup with four beans in four pieces of damp paper towel in four partially-closed ziplock baggies. After four days they had ~1/2" roots. I used a sharp, clean knife to cut off the root as far up as I though was safe, right below where the cotyledons were attached, and put them back in the bags.

Below is a picture of what they looked like on day 8 of the test, with the chopped one on the top. The roots on the chopped one looked eerily like a starfish when they started growing. One interesting thing is that the tissue between the roots and the cotyledons didn't elongate like the unchopped one did. If you were planting the chopped one, I think it would be best to set it right on the top of the soil and let the roots grow down.

It was a fun little experiment!




(I seem to be having problems getting imgur to cooperate today, so I might do some editing/fiddling. The direct link is here: imgur.com/a/aJLtJ)

[reed]

I wonder if that was the issue with the common / runner cross where only one of a dozen or so grew. It has started to dry down a few seeds. Nothing to write home about appearance wise. They are rather small and only a few per pod. I'll plant some next year though and see if I get more segregations.

I posted this over in my thread. It is another apparently common / runner cross even though it sure don't look like it could have come from a runner. Seeds are't much larger than a grain of rice. The mother seed was a normal looking runner bean. 

[philagardener]

Sept 24, 2016 21:00:11 GMT -5 andyb said:

One interesting thing is that the tissue between the roots and the cotyledons didn't elongate like the unchopped one did.

Great observation andyb !  The root tip is a source of the plant hormone auxin, and that flows back and stimulates the elongation of the tissues.  Remove the tip, no auxin, no elongation.  One of the first individuals to experiment with that was Charles Darwin, so you are in good company! 

[andyb]

Sept 25, 2016 6:31:33 GMT -5 philagardener said:

Sept 24, 2016 21:00:11 GMT -5 andyb said:

The root tip is a source of the plant hormone auxin, and that flows back and stimulates the elongation of the tissues.  Remove the tip, no auxin, no elongation.

Oh, that's very cool. Explains a lot of what I was seeing. My guess had been that I'd just removed all or most of the hypocotyl tissue, but the epicotyl growth was also delayed relative to the unchopped sprout. Thanks for the google-grist.

[andyb]

It looks like the first round of possible common x runner seeds are probably real. I planted three Fort Portal Violet Pole x Moldovanesti Buffalo Runner seeds along with the parent varieties earlier this month.

The plants from the crosses are all very similar in form and color and are showing traits mid-way between the parents. Most promising, the epicotyl and hypocotyl are both elongated, where only the epicotyl on the common bean parent is short and only the hypocotyl on the runner bean parent is short. They are also rapidly sending up a vine, while the common parent is bulking up its stem and first true leaves.

Here's Mama:


Here's Papa:
 


and Baby #1:


Baby #2:


and Baby #3, which had an issue with its seed coat:

[jondear]

Nice job!

[andyb]

I have lots of bean flowers right now, with 7 crosses this evening alone. One fun thing is that the flowers of the common x runner plants are pinkish red, with the mother's flowers being purple and the father's completely white. Not too huge of a surprise, since the mother probably had one or more genes that un-broke the pigment pathway from the runner, but still pretty cool to see. I'm looking forward to seeing the bean color(s) and pattern.

[reed]

One of my two surprise runner / common crosses was rather disappointing. The seeds were fairly large bluish colored beans but only one grew well. It was a huge vine, easily 15' or more if it had had the trellis for it with masses of red/pink flowers. Out of all of that I'd say less than 10% of the flowers set pods and a lot of them didn't successfully make beans. The beans I did get are rather ordinary looking, white with brown specks. I got a total of maybe a 1/4 cup that look viable. I'll grow them next year to see what happens, maybe they will segregate into something more interesting.

The second one just showed up this year with tiny beans growing from a normal looking runner bean seed, I have plenty of them to play with next year.

I thought I had evidence that accidental crosses go but ways but realized that isn't the case. I know the one with the tiny beans had a runner bean mother but the other one was already crossed when I got it in a swap the year before. It could have been a later segregation rather than an F1 seed.  

[philagardener]

My runners gave very poor seed set this year, so another chance is definitely in order!

[andyb]

Thanks for the update. I'll be interested to hear what happens next year.

[andyb]

I harvested three seeds from the Fort Portal Violet x Moldovanesti Buffalo F1 plants. These are back-crosses, using pollen from a Fort Portal Violet plant. The picture below has a Moldovanesti Buffalo runner bean on the left, the three seeds from the F1 in the middle, and a Fort Portal Violet Pole Bean on the right.

For reference, it took 22 attempted crosses to get the three beans; one bean per pod. This was quite a bit more difficult than the original common x runner cross. I have about the same success rate with those as with common x common crosses, with seed from about 1/3 of attempts.  

Apparently the blue/purple color is dominant. 

[jondear]

Those are pretty cool beans Andy...

I saved seed from one plant of a "green" bean of mine that I received from an old timer a long time ago. He said his great grandfather grew them, and they've been passed down to now his grandson, I guess. I call them Charlie's bean, but I suspect they might be some sort of fall bean. Maroon seeded. We eat as a fresh snap bean. I grew out about 30 feet for added a couple years ago, about 3 rows away from midnight black beans. One plant (on the very end of the row) was different from the others... My better half noticed this and never picked any. She then one day pointed out the differences between the plant, and sure enough, the dry beans are black... So, one larger bean crossed with a smaller one, not sure if they are indeed a wide cross or not, but I'll give them a lot of attention next season...

[blueadzuki]

Sept 25, 2016 4:33:22 GMT -5 reed said:

I posted this over in my thread. It is another apparently common / runner cross even though it sure don't look like it could have come from a runner. Seeds are't much larger than a grain of rice. The mother seed was a normal looking runner bean. 

I'm not sure it IS such a cross. It looks EXACTLY like trailing fuzzy bean Strophstyles leonitas which grows wild all over the place (especially in disturbed ground). I think an errant seed got into your soil.

[andyb]

Thanks blueadzuki. Here's a little more info on Trailing Fuzzy Beans: plants.usda.gov/plantguide/pdf/cs_sthe4.pdf. Apparently the roots have been used as a food and the rest of the plant as a medicinal, as you've mentioned in a few other posts/threads. Looks like there aren't any wild populations over here on the west side of the US.

[reed]

Very interesting, sure does look like the bean I had except I don't recall anything fuzzy about it. I also have never seen it before so if it's common it isn't so around here. It grew in one of the woman's flower pots so if that is what it is, it must have come in with some of her flowers she got at the green house. I think I'll plant a few seeds next year and observe it a little closer.