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Posted originally on the OSSI plant breeding forum if anyone wants to follow it there too:
"Runner beans, Phaseolus coccineus, are a garden and allotment staple of the British summer. They thrive in the cool and wet weather of the Isles, and struggle to set fruit properly in hot and dry spells.
However, with climate change, that characteristic cool and wet is not necessarily guaranteed anymore.
Runner beans are also boringly green.
Tozer Seeds has bred a number of runner beans with ‘French bean genetics’ that set in hotter, dryer weather and self-pollinate without insect aid.
These are boringly green too, and I’d like to change that.
‘Aeron Purple Star’ is a purple-podded runner bean discovered by (and available from) Aeron Vale Allotments Trust Chairman, Gwilym ab Ioan, in a crop of ‘Polestar’.
It has since grown true and is said to be extremely vigorous, stringless, and superior to ‘Polestar’ in flavour and tenderness.
Whether this variety is the result of a mutation or cross is unknown.
I suspect it is a mutation for the following reasons. There are extremely few purple-podded runner bean varieties with which this variety could have inherited its genetics.
I only know of three sorts; ‘Black Pod’ and ‘Chapman’s Purple’, kept by the Heritage Seed Library, and one which translates to ‘Blue Pod’, available from a Danish grower.
I’m also doubtful that ‘APS’ is the result of an intrageneric cross with P. vulgaris. Perhaps not impossible, but I have read that without embryo rescue it is unlikely to develop viable offspring with P. vulgaris as the pollen parent.
However, as one of Tozer’s newly bred self-setting runner beans, the ‘APS’ progenitor ‘Polestar’ may have P. vulgaris genetics, and if so it may be more receptive to P. vulgaris pollen.
‘APS’ could in fact be the result of a cross with a purple-podded French bean, nullifying my previous reasoning.
So, there are a lot of unknowns and suppositions, but this year I will attempt to make a start on unraveling some of these mysteries:
I’ll be making crosses to the Tozer runners with yellow, red and purple-podded French beans. Also crossing the Tozer runners with common runner beans to see if the F1 progeny is receptive to vulgaris pollen.
There are experts and professionals on this forum who have the knowledge to correct my mistakes and point me in the right direction regarding this project, perhaps even to make most of the experiments unnecessary.
What is unknown to me is likely common knowledge in literature, but I haven’t yet found the studies. Any advice and comments, as always, are greatly appreciated."
"Runner beans, Phaseolus coccineus, are a garden and allotment staple of the British summer. They thrive in the cool and wet weather of the Isles, and struggle to set fruit properly in hot and dry spells.
However, with climate change, that characteristic cool and wet is not necessarily guaranteed anymore.
Runner beans are also boringly green.
Tozer Seeds has bred a number of runner beans with ‘French bean genetics’ that set in hotter, dryer weather and self-pollinate without insect aid.
These are boringly green too, and I’d like to change that.
‘Aeron Purple Star’ is a purple-podded runner bean discovered by (and available from) Aeron Vale Allotments Trust Chairman, Gwilym ab Ioan, in a crop of ‘Polestar’.
It has since grown true and is said to be extremely vigorous, stringless, and superior to ‘Polestar’ in flavour and tenderness.
Whether this variety is the result of a mutation or cross is unknown.
I suspect it is a mutation for the following reasons. There are extremely few purple-podded runner bean varieties with which this variety could have inherited its genetics.
I only know of three sorts; ‘Black Pod’ and ‘Chapman’s Purple’, kept by the Heritage Seed Library, and one which translates to ‘Blue Pod’, available from a Danish grower.
I’m also doubtful that ‘APS’ is the result of an intrageneric cross with P. vulgaris. Perhaps not impossible, but I have read that without embryo rescue it is unlikely to develop viable offspring with P. vulgaris as the pollen parent.
However, as one of Tozer’s newly bred self-setting runner beans, the ‘APS’ progenitor ‘Polestar’ may have P. vulgaris genetics, and if so it may be more receptive to P. vulgaris pollen.
‘APS’ could in fact be the result of a cross with a purple-podded French bean, nullifying my previous reasoning.
So, there are a lot of unknowns and suppositions, but this year I will attempt to make a start on unraveling some of these mysteries:
- I am hoping to find out if anthocyanin expression in the pod is dominant, co-dominant or incompletely dominant by crossing ‘APS’ with green runner beans. There's a variety called 'Yardstick' that has purple striping.
- I will attempt to test whether the P. coccineus x P. vulgaris varieties bred by Tozer set viable seed when subsequently pollinated by P. vulgaris. There are many of these runners available in the UK - this year I will be making crosses with ‘Moonlight’, ‘Firestorm’, ‘White Lady’, and ‘Wey’, but also on the market are ‘Aurora’, ‘Celebration’, ‘Firelight’, ‘Saint George’, ‘Snowstorm’, ‘Stardust’, ‘Sunset’, ‘Tenderstar’ and ‘Snowdrift’.
- Veitch’s Wonder’ is a vulgaris x coccineus dwarf green bean of J. Veitch & Sons, 1910, that I will be using in some experiments as a ‘bridge’ between the two species. The seeds of this variety bear striking resemblance to runner beans.
I’ll be making crosses to the Tozer runners with yellow, red and purple-podded French beans. Also crossing the Tozer runners with common runner beans to see if the F1 progeny is receptive to vulgaris pollen.
There are experts and professionals on this forum who have the knowledge to correct my mistakes and point me in the right direction regarding this project, perhaps even to make most of the experiments unnecessary.
What is unknown to me is likely common knowledge in literature, but I haven’t yet found the studies. Any advice and comments, as always, are greatly appreciated."
) fortunately runner beans are a little more frost hardy than French beans.
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