In 2014, as you'll remember, I cross-pollinated the mangetout pea varieties Golden Sweet and Bijou; the former being yellow-podded and the latter having large, wide, green pods. The aim is to introduce the genes for yellow pods from Golden Sweet into the Bijou line.
Last year's F1 plants threw in one surprise; I got everything I'd expected – tall plants, purple splodges in the leaf axils, bi-coloured purple flowers and small, green pods. F1 hybrid seeds are homozygous, which basically means they're genetically identical and only the dominant genes are expressed. The surprise was that instead of being fibreless, the pods on all six F1 plants had a fibrous layer like shelling peas, making them inedible. I've read in several places that mangetout pea plants lack the dominant genes for making fibrous pods. I also understand that dominant genes don't hide themselves away like recessives do, so I've no idea where these fibrous pods were coming from; perhaps G.S. has a fibre-making gene after all. The F1 generation produced over 200 seeds; enough to keep me busy for a few seasons if I wish!
This year, I'm growing out the heterozygous F2 generation, which is where the fun begins. Each seed should be genetically different, and potentially each seed is a new variety. The genes begin to segregate into their parent lines, which is exactly what I've found. Of the forty-odd plants I've grown (all tall), I've had small, yellow mangetout like Golden Sweet; both small and large, green mangetout; and large, green, fibrous pods.
One yellow-podded line looks as though it might be worth growing out – its completely fibreless pods curl upwards rather than lying flat like Golden Sweet's do.
And then there's this; a single plant has produced large, fibreless, yellow pods. I know they're fibreless by the way the seeds deform the pod walls as they mature. The plant is short-ish and a bit scrawny, and the pods seem to become greener as they age; here it's compared with Golden Sweet, which is the small pod on the left of this photo. I tasted one young pod, whichch i found tasted acceptable but wasn't quite as tasty as Golden Sweet. This, however, may be the prototype I'm looking for. Next year's pea-growing is looking exciting!