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Old 3 Weeks Ago   #16
rxkeith
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i am getting a fair amount of seed from the bean cross, more than i was expecting
given the frost we got about ten days ago. beans left out have dried down to leathery
stage which is good enough for seed saving.


the surprise i am seeing is not all seeds are the same.
most of the seeds look like what i planted, dark blue/black with light brown
mottling. i am also getting all blue/black seeds similar to grandma gina, and seeds
that look like uncle steve seeds, light tan with purple whorls.
the bean pods that are a lighter green color are giving me light plum purple seeds.
the beans are growing on a separate fence so no chance of getting mixed up with grandma gina or uncle steve both of which i am growing.


i think i remember reading that with a bean cross, according to one of our bean experts, what you get is a stable cross right off the bat unlike a tomato cross
that has to be stabilized to f7 or f8. is that correct?

so what gives?





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Old 2 Weeks Ago   #17
Tormato
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Are these seeds completely mature and completely dry?

My experience with black seeded varieties, is that slightly immature seeds will either be light purple or light blue.
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Old 2 Weeks Ago   #18
rxkeith
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gary,


i thought about that.
none of the bean pods had dried down as i would have liked. frost prevented that
from happening. that doesn't explain the seeds that look like uncle steve beans.
every seed i planted on the fence looked like the seeds i mailed you. dark blue/black
with lighter brown mottling. the beans that the lighter purple seeds came from looked a little different. pods weren't quite as wide as the other beans and didn't have the
purple streaks right off the bat.
i have seeds that look like each parent, seeds that look like the crossed seeds i planted, and the lighter purple seeds. i wasn't expecting that.

i don't have enough bean genetics knowledge to explain it.






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Old 4 Days Ago   #19
Fusion_power
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What you are seeing is typical of beans, but is confusing because it represents something you have not experienced before. The seed testa of a bean is maternal tissue, meaning that it is derived from the mother plant and therefore does NOT represent the genetics of the seed inside. For this reason, the original crossed seed looked just like your Uncle Steve's because it had the seed coat of the mother plant. For the same reason, when you grew that crossed seed last year, the testa colors represented the color of the maternal plant which grew from the f1 seed. This year growing F2 seed , you recovered the seed coat color of both original parents, the seed coat color produced on seed from the F1 plant, plus a few with mixed traits like blue with swirls etc. It will get really interesting if you grow some of segregating seed next year because recessives recombine and show up in seed size, testa color, flavor, etc.

The way I work from that kind of cross is to find the individual plants with traits I want to propagate and grow them out. On average, about 3 plants out of a hundred are really worth saving and growing because they carry a unique combination of traits.

I will give a really good example from my growout this year of a cross between Fortex and PI207373 (a small black bean with intense purple pods). I am attempting to bring high disease tolerance from PI207373 into a long high quality bean like Fortex. This year, I grew a row with roughly 100 F3 plants. F3 is where most of the recombination of traits shows up with beans because you can see the recessive traits. I got plenty of purple pod beans and some with green pods, but I also got two totally unexpected beans. One is a beautiful red snap bean, the other is a yellow snap bean. Neither parent showed red or yellow in any way. But when I made the cross and started growing out the offspring, the result was this:

http://www.selectedplants.com/miscan....29.beans3.jpg

Last edited by Fusion_power; 4 Days Ago at 07:15 PM.
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Old 4 Days Ago   #20
rxkeith
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thanks, for the explanation.

that answers some questions.
makes me wonder though how the heck to identify individual plants
with superior genetics when the vines are all entwined on the bean fence.
sounds like i should plant a mix of the f3 seeds rather than just one color
type, and see what i get, eh. i would also have to get busy with the roto tiller
to grow a hundred plants of just the cross along with everything else thats growing.
one thing i can say about the cross so far is very few seeds have split seed coats.
we have had above average rain for the year so would not have been surprised to
see more than i did.

at what filial generation can i expect to see a stable bean variety? tomatoes are
f7 to f8 depending. are beans similar?
it will be interesting to see what happens, that is for sure.



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Old 3 Days Ago   #21
Fusion_power
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The thing with bean crosses is that you have to be very observant. I had a row growing of the crossed seed that was somewhat intertwined. Since PI207373 is not a snap type bean, and one of my desired traits is a snap bean, I watched the crossed plants carefully for any beans that showed snap bean traits. That is how I first spotted the red bean plant.


How long it takes to stabilize any cross entirely depends on how many traits you are selecting for and whether they are recessive or not. It is much easier to stabilize recessive traits. Also, with any breeding effort, making a cross of necessity compromises traits such as bean length in the Fortex hybrid. It is nearly guaranteed that I will have to make a backcross to Fortex to get back the bean length that I want. In your cross, the number of compromised traits is limited because the parents are highly similar. You could for example select a bean similar to Uncle Steve's with larger seed and higher productivity with flat pods. That would be far easier to achieve than in my case with a cross involving a small disease tolerant dry bean with a highly selected stringless very long snap bean. I am selecting for any color other than purple, long snap phenotype, excellent flavor, and most important, very high levels of disease resistance. To more directly answer your question, you can probably stabilize something interesting in 5 generations. I will probably have something interesting in 7 or 8 generations and then will have to backcross and do another 5 or 6 generations to get a stable line with the desired traits.
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Old 3 Days Ago   #22
rxkeith
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thanks again darrel, i appreciate you sharing your knowledge and experience in
plant breeding. me, i'm just a backyard putzer with a chance cross thinking, wow,
neato, now what?

goals, i suppose would be a good tasting snap bean, earlier maturing so i can save
seeds. probably will be a flat pod, since both parents are flat, and pods will be
purple streaked at some stage of maturity. never know what any lurking recessive
traits might show up. with two great tasting parents, i should come up with something worthwhile.

i had thought about a cross of the two beans in the past, wondering what would
result. now, i have one. it will be fun to see what happens.




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