The Biologist Is In

My Phaseolus coccineus (runner bean, or ayacote) project started with two varieties from Mexico.

Those started blooming on Sept 6, 2023.

The F1 bloomed on Aug ~6, 2024.

The F2s started blooming on July 1, 2025.

The F3s started blooming on June 20, 2026.

I lucked out in that my starting varieties had some recessive genetics for precocious blooming. I also lucked out in one of the 8 immature and deformed seeds I got the first year being a hybrid.

That luck and a little persistence is what it took to adapt these plants to my much shorter season.

I started with purple and yellow varieties. My goal was to cross them to see if I could later dissect out the red and yellow pigment pathways to yield a blue-seeded version.

Later, I learned more about the genomics of this species (and the related common & lima beans). Specifically, the genes for the enzymes needed to make red and blue anthocyanins are tightly linked in a region with very low recombination.

This makes it much harder to separate the red and blue pathways.

Fortunately, I already had produced a variety of common bean (Phaseolus vulgaris) with only the blue pathway active in the seed coat, and the two species can cross.

Among the F2s of that initial P. coccineus cross, I was able to isolate a plant that had neither red, blue, nor yellow pigment expressed in the seed coat. The seeds had a cream/pale-tan color that told me the flavonoid pathway as a whole remained active.

This year, I'm trying to cross the cream P. coccineus with my blue P. vulgaris.

Making predictions about this cross will require a bit more detailed knowledge about the specific gene versions I'm working with. Fortunately, I have some of that information.

The yellow P. coccineus variety got that color from an active version of the 'G' gene (for flavonol synthase).

The purple & my cream P. coccineus varieties have this gene disabled. My blue P. vulgaris also has this gene disabled.

So, the F1/later will have no yellow pigment.

The yellow P. coccineus variety had a version of the 'V' gene (for F3'5'H) that couldn't be expressed in the seed coat or flowers.

The purple P. coccineus variety had a version of the 'V' gene that could only be expressed in the seed coat.

The blue P. vulgaris variety has a version of the 'V' gene that is expressed in both the seed coat and the flowers. This was revealed by an earlier hybrid between a P. coccineus & my blue P. vulgaris, which had magenta (red & blue) flowers.

The yellow P. coccineus variety had a version of the 'R' gene (for F3'H) that could only be expressed in the flowers.

The purple P. coccineus variety had a version of the 'R' gene that could be expressed in the seed coat and flowers.

The remaining mystery is about the P. vulgaris version of the 'R' gene. I know the version I have isn't expressed in the seed coat, but I don't know if it will still be expressed in the flowers.

With all these details... the hybrid between the cream P. coccineus and the blue P. vulgaris is expected to have blue seeds and magenta (blue & red) flowers. I'll see those next year at the earliest.

The following generation will clarify the mystery about the P. vulgaris 'R' gene version.

¼ of the F2s should have red flowers.

½ should have magenta flowers.

The remaining ¼ will have either magenta or blue flowers if that P. vulgaris 'R' gene is active in the flowers or not.

That F2 generation will be complicated by there being another gene from P. coccineus allowing strong expression of anthocyanins in the flowers, while the P. vulgaris version only allows pale flowers.

And then there's the instability of P. coccineus chromosomes in a hybrid with P. vulgaris cytoplasm.

That tends to lead to the loss of P. coccineus chromosomes/traits in later generations, but could be overcome with strong selection for P. coccineus types.

Those same genomic details that led to me trying to introgress the blue seed trait into P. coccineus also puts a big hindrance into the project to make a blue lima bean (Phaseolus lunatus).

Lima beans and common beans can't cross in any useful way, so I'm stuck with trying to find the right mutation(s) in available lima beans.

Conceivably, I have (or rather, can produce) the sequence data needed to engineer a blue lima bean. Unfortunately, lab techniques to engineer beans have very limited success rates.

In my most productive year, I grew ½ gallons of dry beans on a 10 ft long trellis. A half gallon of dry beans weighs roughly 3.5 lbs.

You need roughly 60 lbs of dry beans per person to live off of for a year. From my garden efficacy numbers, that 60 lbs could be produced on 171.43 ft of trellis. For three people, that comes to 514.29 feet of trellis.

A more realistic diet would include a range of other crops, but you'd need the same order of magnitude of garden area.

A home garden is not the solution to food not being available.

However, if you have the time, resources, and land to grow a garden, it can supplement the nutrition you have in your diet while relying on farmers to meet your basic caloric needs.

I'm at 45°N with a short growing season.

Those further south can potentially have multiple crops in rotation year-round, while I mostly can only have one crop a year for any given garden area.

https://texelsusa.org/about-the-breed/information/

The variety is raised for meat, but also used as a ram with other breeds to produce lambs that put on muscle faster while still having the longer wool characteristics of their dam.

They look like they could take on predators by themselves and maybe tear them up to eat them.

A few years ago, through luck and vibes, I managed to produce this blue colored bean variety.

Some of my dry beans from this year.

My F2 runner bean (Phaseolus coccineus) population seems to be producing six color classes. I still have many pods left to process as they dry before I can estimate the ratios of the different seed colors needed to estimate the genetics ratios.

The goal of this project was to produce a blue-seeded version of this species (Phaseolus coccineus) as a test of my models for how seed color genetics works in this genus from my studies of common beans (P. vulgaris).

It's beginning to look like I may have done it.

If I can somehow stabilize varieties from each color classes over the next years, I'll have a decent color palette for making some seed art.

It would be better for that task if the seeds were tiny instead of giant, but there's only so much I can do.

A bean collector in Europe has a line with a distinctly red color. If it didn't have black marks like most common varieties of the species, it would be a great addition to this set.

I can make some comments about the color genetics in this population already.

The lighter shades are much less common than the darker ones. Blues are much less common than the other colors, so light blues will probably be -very- uncommon, but possible if I were to grow out enough F2 plants.