Sunday, 25 April 2010

Luna Trick F4 seedlings go forth

Luna Trick F4 seedlings
Luna Trick F4 plants all tagged up and ready to plant out

Well both my F4 Luna Trick batches are now planted out in the garden - the standard version and the sugarsnap version. They were sown a couple of weeks apart, in the hopes that their development will be staggered somewhat and I will be less overwhelmed by the workload. Growing peas is not in itself much of a workload … they are independent little dears. But breeding projects have a habit of being very time-consuming, especially this one, because I'm being very careful about collecting individual data on each plant. It takes a lot of effort to label and track every single plant in the project and write down detailed notes for all of them. But it will save me time in the long run because I will be able to select more precisely for the traits I want - and it will teach me a lot about the genetics involved, and pea genetics generally. By labelling every plant with its own number, which includes a code for its specific pedigree, I can identify which lines are true-breeding for dominant traits such as tallness. I'll be able to see which pedigree lines are entirely made up of tall plants and save seed only from those, which should eliminate unwanted recessives very quickly. If I pooled the F4 seed and selected from the whole group, I wouldn't know which of the tall ones were hiding unwanted recessives. So although it would save me a lot of note-taking for this year, I'd be weeding out unwanted dwarf types for years to come.

Luna Trick F4
Luna Trick F4 plant, photographed today. This one is the offspring of LT10, which so far looks to be the only line which is true-breeding for tallness.

As these plants are so important to me, I take extra care with them. They have been raised in rootrainers, which in my experience are far more reliable than any other method for producing strong seedlings and healthy plants. The expense of rootrainers doesn't necessarily make them a good option for pea cultivation generally, but for me they are a worthy investment. The next important thing is soil preparation. I don't bother with fertilisers because peas don't really need them … they have a unique mechanism for producing their own. But what they do benefit from is a digging in of organic matter of some kind. Compost is good. Horse manure is excellent, but in the light of the disgraceful aminopyralid poisoning of Britain's grasslands, I'm not using manure in my garden at the moment. Removal of perennial weeds such as couch grass root is also important, because it's difficult to weed around peas once they get established.

The other special care I provide them with is protection from the weather. Peas are hardy, and I'm not at all worried about the April frosts. The cold nights we're getting at the moment are bringing out some lovely red colour in the leaves of peas capable of producing red colour (which Luna Trick isn't) but it's not harming them in any way. What peas do suffer with though is the cold blustery winds that are so common at this time of year. Having said that, this year has been astonishingly warm and settled, so it hasn't been an issue. They are only really vulnerable to this when they're young and first planted out … the cold winds wither and damage the young growing tips. Once they've got established after a couple of weeks, they are a lot more robust. So what I do for precious peas when first planted out is set up a netted fabric screen round them. Horticultural fleece is the conventional choice, but the lovely old lady who lived in my house before me has saved me ever having to buy any. The house was festooned with about 30 miles of net curtains, which do an admirable job in taking the edge off the winds without losing too much sunlight. I'm growing Luna Trick in a frame made of bamboo canes, so it's the work of a moment to attach the net curtains round it with clothes pegs. I do have to be careful to lay a few unwelcoming heavy twigs around the outside as well, because my cat finds it amusing to charge into the net curtains at high speed.

Protecting pea seedlings the cheap way
Doesn't that look grand? Well all right, it looks bloody awful, but old net curtains are very effective at filtering the English spring breezes while the seedlings get established. I make no apology for the state of my garden ... the breeding and heritage conservation work is so time consuming I don't have time to make it look pretty as well.

I keep each of my breeding projects in their own personal filing containers, made from ultra high-tech re-used cat food boxes. When I picked up an empty box the other day for a new project I'm starting, it turned out not to be empty. Rattling around inside were about a dozen lovingly sorted and labelled bags of Luna Trick seed from the best of my F3 lines, and three unmarked whole pods left loose in the box. I'm afraid I do have this bad habit of failing to label things and then forgetting what the hell they were. These seeds were all harvested earlier in the season, when I was selecting the best plants and harvesting the pods as they matured. I remember harvesting them but don't remember shelling them and boxing them up, which serves me right for smoking too much weed in my youth. There were about twelve pedigree lines in labelled bags, including a load of extra seed from my best plant LT10 … so I've sown another fifteen of those. You can never have enough LT10 as far as I'm concerned. And by starting off another batch of them now, in addition to the ones sown about a month ago, I'm greatly increasing my window of opportunity to make crosses with them.

The loose pods were something of a mystery, but there had to be a good reason I kept them separate instead of bagging them up like I did the others. According to my pollination records, which can also be a bit sporadic when I'm busy, I did some crosses between the best Luna Trick F3 plants and one of the trial varieties I grew in 2009, Buerre Cosse Rouge. This latter is quite a special little variety because it has red-sploshed pods … not quite the deep consistent crimson I got in my red-podder project, but reasonably close to it. And it's a sugarsnap type. It does have some frustrating weaknesses though. The plants (in my trial at least) were tiny and not very strong, and the yields absolutely miniscule. It produced miniscule pods that have about three peas in them, and more often than not they withered and fell off before they reached maturity. I didn't even get to taste Buerre Cosse Rouge, because I was struggling to scrape together enough seed just to regrow it this season. In doing these crosses, I had in my head the idea that I might get some red-pod gorgeousness into the voluptuous sweet abundance of Luna Trick. There is a chance - only a chance mind - that these loose pods had been kept separate because they were hybridised ones.

Fortunately for me and my slack incompetence, I should be able to find out fairly quickly. My old friend gene A will help me out. It's the gene which switches on the colour pigment in peas. Luna Trick doesn't have it - it's true-breeding for the recessive a a genotype which cannot produce anthocyanin pigment. Buerre Cosse Rouge presumably has the dominant A A type, because it has lots of anthocyanin colour. Crossing the two will give me the a A genotype, in which the recessive colourless gene gets elbowed out. In other words, if the seedlings show any trace of red colouring, I will know they are from a cross. If they turn out to be the normal unpigmented Luna Trick type, then I'll know they weren't from a cross. Thus nature sometimes forgives us for poor labelling.

(The seedlings have now emerged and so far are not showing any obvious traces of anthocyanin. Arse!)

1 comment:

Vegetable Heaven said...

'Mystery' sounds like a good pea name!

I'm enjoying your pea posts immensely. You know why!

Speaking of Arses, I found a weedy pea seedling of my F2 crosses lurking behind a stronger plant and it hadn't been labelled and incuded in my table. I now have an 8a! Pink, wobbly arse!