Breeding runner beans

[robertb]

I started a breeding project this year, which got off to a bad start due to major problems drying them in the very damp autumn. They may have got frosted as 99% of the beans rotted after looking fine when taken from the pods. I've pretty well lost two varieties - Black Pod and Mrs Cannell's Black - but I've gained more so I can try again next year. One, Aeron Purple Star, is stringless, while St George is semi-stringless. Others have strings. Is the stringless gene recessive, or is more than one gene involved? Has anyone got any experience of breeding these?

[blackox]

All I know about dominant and recessive genes in runner beans -

Colored flowers are dominant over white. Red is dominant over pink, which is dominant over white.
White seed coats are dominant over colored.

My guess would be that the stringless gene would be recessive, with a few other genes working in the background.

[robertb]

My own guess as well, but no doubt I'll find out next year!

[Joseph Lofthouse]

I believe that there are always multiple genes involved in every trait, in spite of whatever simple-minded academic theory might be spouted off in biology classes. In the real world there are thousands of genes interacting to produce any particular trait.

[oxbowfarm]

Probably much more expertise with breeding runnerbeans in the UK than most places, since they like it there so well.

[robertb]

I've never heard of anyone doing any deliberate breeding. The only new amateur variety I have appears to be descended from an accidental cross. It's similar to Blackpod, but stringless. I haven't grown it out yet.