Pea breeding projects are go!

What do we have here? 100% germination from 7-year-old pea seeds, that's what!

These are red-podded mangetout peas which represent my best hope of developing a really good, tasty red podded pea. They're a cross between two heritage varieties, Golden Sweet x Carruthers' Purple Podded. These are an F5, so they're five generations removed from the original cross I made. Most of them are the offspring of one particular plant which was exceptional, but I also sowed a few from a couple of other plants which were also very good. I'm expecting most of them to have red pods, but there may be a few yellows, because of the possibility of a recessive gene lurking in their genepool which switches off anthocyanin production. If I'm really lucky they might not be carrying this gene, in which case they should all be red. But I can already see, even when they're just a few days old, that a few of the seedlings look completely green, while the majority have a red blush on the stem. The absence of a red blush may be an indicator that they can't produce anthocyanin, the pigment responsible for red/purple/pink colours in peas. If the anthocyanin switch-off gene is in there, then I would expect it to show up in roughly a quarter of the plants – a simple Mendelian ratio. We will see – it will become more apparent as the seedlings grow, and it's likely that I'll be able to deduce the pod colour without having to wait for them to produce pods.

This project has been languishing for a few years as I've struggled through my bereavements, but fortunately I'm able to pick it up where I left off. I sowed 56 peas in this tray (two in each cell) and they all popped up within 4 to 6 days, with no duds. The seeds were from a crop I harvested in 2019, and no I didn't have special facilities to conserve them – as is my wont, they were stored in grip-seal baggies in a cat food box on top of a bookcase.

I'm all for challenging myths in gardening, of which there are so many. The books on my shelf (just below the cat food boxes) claim that pea seeds have an expected lifespan of 1-2 years. Older than that and they won't germinate, or if they do then they'll make weak plants. I know from experience that this is nonsense. In a previous iteration of this breeding project I germinated 9-year-old pea seeds without any problems at all and the plants were vigorous and healthy. There are limits, of course. I recently experimented with trying to germinate 18-year-old tomato seeds, and it didn't work, despite my best efforts with a heatpad and some home-made gibberellic acid. But whatever the received wisdom says, there's always hope, and it's always worth a try.

I'm thrilled with 100% germination, and very excited to see how they develop.

Meanwhile, here's some I prepared earlier.

I had 98% germination from this batch, which were also 7 years old and from the same cat food box. These are from my pink-flowered pea project, Alderman x Salmon-Flowered, which is aiming to produce beautiful tall delicious shelling peas, but with two-tone pink flowers instead of the standard white. If you've read previous posts on this blog about my pea projects, you'll know that white flowers in peas are caused by the gene which switches off anthocyanin production. Almost all modern peas have it (and many heritage varieties do too) but if it wasn't there, peas would naturally produce PURPLE flowers, and have purple colouring in the leaf axils, peas and pods. As all my projects are concerned with making lovely colours, I aim always to eliminate the "anthocyanin off" gene, which is recessive, so the little bugger pops up in later generations where you didn't know it was there. 

The pink flowers in this project are (I believe) the result of a modifier gene which deletes one of the pigments responsible for purple flowers, giving them a paler, pinker hue.

The photo above shows them when they were in the greenhouse waiting to be planted out. Note that I DON'T advocate leaving them quite this long. If allowed to grow much bigger than this, they'll start grabbing each other with their tendrils and then it becomes really difficult to disentangle them without damaging them. However, the weather forced my hand on this occasion. I was about to plant them out when I saw that a blustery storm was forecast a few days away, and peas really don't like blustery windy weather. So I decided that leaving them in the greenhouse for a bit longer was the lesser evil. As it turned out, I was still able to plant them out before they reached the nightmare tangly tendril stage.

Here they are in their new home, and I'll be writing another post about the swanky new pea frame which I've set up for them.