Sunday, 13 June 2010

Beautiful Luna Trick

Twilight Luna Trick F4

Everything's happening so fast in the garden at the moment I'm barely able to upload my photos onto the computer before they're out of date (however did I manage in the days when I had to send films to Bonusprint?) so I'm just going to chuck a few pictures of my Luna Trick F4 peas up here to show you how they're getting on.

I'm very happy with the way things are going with this variety. You may recall, dear reader, that I have two separate batches of F4 plants because last year's Luna Trick F3 segregated into mangetout (snow) types and sugarsnap types, and as I'm intending to develop them as different varieties I'm growing the two types separately. Or I thought I was. As it turns out I have sugarsnaps among the mangetouts and mangetouts among the sugarsnaps, so balls to that idea. The former situation was entirely expected - I knew some of the mangetout-podded plants I saved seed from last year would've sneakily closeted away the recessive n allele in their genome, ready to spring forth unbidden in future generations. This recessive allele singlehandedly creates the sugarsnap type simply by thickening the pod wall, transforming a wide flat pod into a slim, round, plump and juicy one. I love both types, so I'm open minded about what I get. But the recessive nature of this gene means that it will be hiding itself in a proportion of the mangetout plants for a generation or two yet, and I won't know which ones until I grow their offspring.

Luna Trick F4 blossom
Upside down flowers? Well why not.

The most promising F3 plant I had last year was one called LT10. (There's nothing arcane about this name, it was simply the 10th plant in my Luna Trick trial to get a label stuck on it.) It was a tall mangetout-podded plant with a divine flavour. And the gene gods were smiling on me, because when I started growing out the F4 it turned out to be the only one of my mangetout lines which was true-breeding for tallness, which is what I want. All the others had hidden recessive dwarfing genes lurking in them. If I save seed only from LT10's offspring and not from the other lines I should have no more trouble with dwarves. I supposed it would be too much to expect LT10 to be true-breeding for mangetout pods as well, and indeed it has presented me with a goodly smattering of sugarsnaps. They may well be good enough to contribute to the development of my sugarsnap line, but in the breeding of a stable mangetout line they are a pain in the backside.

While I was expecting to get sugarsnaps in the mangetout batch, I certainly wasn't expecting to get mangetouts out of the sugarsnaps - that was a complete surprise. A recessive trait is by definition true-breeding. It can only express itself when a matched pair of recessives get it together and there are no dominants involved to spoil the party. As the mangetout-pod trait is dominant it couldn't possibly be present, hidden, in any of the sugarsnap plants I saved seed from last year. So I was intrigued to see not one but several of the F4 sugarsnap plants developing mangetout pods. How could this be? Is there some other gene at play which suppresses the sugarsnap gene? Did the faeries dig my plants up and move them in the night? The solution became obvious when I looked at the identification tags of the plants concerned. They were all from the same parent plant, LT2. I'm growing ten of LT2's offspring, and the majority of them have mangetout pods, with a few sugarsnaps. While I hesitate to declare a Mendelian ratio on such a small sample size, it seems obvious that there is one and I made a mistake in classifying LT2 as a sugarsnap when it was nothing of the sort. Sometimes mangetout pods look a bit sugarsnappy. It's a relief to find such a simple explanation, and it's one of the reasons I number my plants at the F2, F3 and sometimes F4 stage - as laborious as it is, it enables me to track the pedigree of each individual, to find patterns in weirdness and resolve mistakes.

Luna Trick baby sugarsnap pod
The first Luna Trick F4 pod, still with its little petal nosebag on. This one is a sugarsnap type (honest).

Luna Trick F4 sugarsnap pod
The same pod five days later, now with a beautiful luna crescent shape.

In the last couple of days I've managed to do the first couple of taste tests, and so far they've all been very nice. Flavour is the most important thing I'm selecting for, apart from healthy vigorous plants which goes without saying. But I'm also looking out for crescent moon shaped pods, particularly among the sugarsnaps. I'm also mindful of the colour intensity. For the most part Luna Trick has a stronger and longer-lasting yellow colour than its yellow parent, Golden Sweet, but in last year's batch I did have some which faded to pale washy green a bit more quickly than I would like.

I'm also busy with the scalpel using Luna Trick for various hybrids, particularly as it represents a superior alternative to Golden Sweet, so rather than doing backcrosses to Golden Sweet in my Peachy and Red-Podded lines, I'm using Luna Trick instead. I'm making these crosses with both the mangetout and the sugarsnap types, which I'm hoping will give me a red sugarsnap as well as the decent flavoured red mangetout I've been coveting. I've also made some crosses with Salmon Flowered (the antique umbellatum pea) which is more of an experimental endeavour. What I have in mind is to extract the gene which makes the rosy pink flowers, which would look lovely on a yellow-podded pea. But my weird imagination also conjures up a vision of a yellow-podded umbellatum, crowned by a giant clump of sticky-outy golden sugarsnaps. What a spectacle that would be.

Luna Trick F4 pod
This is one of the mangetout type pods.

5 comments:

Vegetable Heaven said...

There are so many Holy Grails to strive for in pea breeding aren't there? My next cross is going to be Carruthers pollen into Magnum Bonum. Magnum Purpureum? You never know!

Your Luna Trick line is proving really exciting.

Certainly, you don't need to be in a hurry in this game!

IAP said...

I've just sown the Luna Trick that you sent me. It's very late in the season, but given a cool Summer... Or maybe I'll be selecting for heat tolerance!
I love your term 'patterns of weirdness'. Sounds like the title of a Brian Eno track.

lieven said...

Stunning sweet beauty, Rebsie! I really love snap peas - any type - as well as colourful edibles in general, which explains why I've been following your work & admiring your pics for a few years. Keep going for gold!

Greensparrow said...

I am so excited! I just found your blog, and I am thrilled to discover another backyard vegetable breeder! I've been playing mostly with squash, tomatoes and peppers (better suited to my hot summers than peas) -- well, in addition to all my flower breeding projects.

Rebsie Fairholm said...

Kath - Magnum Bonum x Carruthers' Purple is one of the hybrids (F2) I have in the garden at the moment! I must post some pictures. They are producing very tall plants with purple splodged pods ... none fully purple so far.

Ian - could still make a song title out of that! It shouldn't be too late for a pea crop, I'm hoping to sow a couple more yet. Your spuds are doing well ... just starting to show flower buds now.

Lieven - wonderful to hear from you, thank you!

Likewise Greensparrow ... nice to meet you.