12 December 2012

Coloured Carrot Project progress

Compared to my successes with coloured snow peas, progress on my root vegetables has been slow – that’s what happens when you start on biennial vegetable breeding.
I planted carrots a number of carrot varieties in the middle of summer last year – Harlequin F1 multicoloured, Purple Haze F1 (a purple skinned orange cored carrot),Lobbericher heritage yellow, Belgian White, French Round, Chantennay, the last of some old Three  Colours Purple that was lying around in the seed shoe box, and a scatter of Baby carrots, that have successfully self seeded for a number of generations, but from a relatively narrow gene pool, since I’ve had 2 or 3 go to seed for the last couple of years.

But some problems arose. First, the French Round didn’t emerge, and I unsuccessfully tried a few other small round carrots until I got a variety to germinate. The delay means they are now out of synch with the coloured varieties, and I don’t think I will be able to get a cross happening.

A further complication with the timing has to do with the approach I used, what Susan Ashworth in ‘Seed to Seed’ refers to as ‘autumn winter spring’ seed production. Some further explanation. A normal biennial root crop would go through the following sequence. Seed sown (or fallen on the ground) would germinate in spring, with damp soils, and warming temperatures. The plant grows over spring and summer, and as the seasons progress, develops a swollen root. Come autumn as temperatures drop the tops stop growing, and the plant hunkers down for the winter, with plenty of energy stored safely away in the root to fuel early growth next spring. When the next spring arrives, the plant switches to reproductive mode, growth restarts, but instead of putting energy into a storage root, it draws on that stored energy to develop flowers. These get pollinated in summer, develop seeds, which dry off over autumn, and are shed on the ground ready to start the cycle over again.

A gardener wanting vegetable seeds of the best quality would dig up the roots in winter, inspect for desirable characteristics and select the best roots for replanting (and eat the rejects). In early spring, replant the good ones, and let them cross pollinate to produce seed.

But what if I just wanted to cross some existing varieties and haven’t got 2 years? This 18 month cycle can be shortened by sowing in late summer, getting good growth to develop, leave the roots in the ground, and letting the plants flower normally in spring. I’m not doing any selection, just wanting to cross varieties at this stage, so I don’t need to inspect the roots.
But when I want to see the results of my cross, I’ll need to revert to the 2 year cycle.

A further complication is cytoplasmic male sterility. Time for another post.

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