05 April 2012

The Parsnip and Carrot Projects

Ms Templeton loves a roast parsnip. But I've never really had much luck with root vegetables in the vege garden. In part, this is because Bendigo, where I live has been in the grip of a decade-long drought, and the time for sowing carrot, parsnip and beetroot seed is spring. But this is when I've been devoting my limited water (Bendigo was under intense water restrictions, virtually banning any water use outside the house) to tomatoes and salads for summer consumption, rather than thinking about keeping root crops alive, and thriving, until late autumn.

Root crops present another couple of problems. The can be rather finnicky about germinating, and growing as seedlings in trays and transplanting them can result in misshapen and forked roots - not very attractive to Ms Templeton's delicate sensibilities. So they are best direct sown in the bed they are to grow in - the best advice is to sow them then cover the row with a wide plank, checking periodically for germination. One cunning correspondent then props up either end of the board on a brick, allowing the germinated ones to get light and grow, but also shading the row while the recalcitrant late germinaters appear. Did I mention that germination is patchy, and can extend over a few weeks?

A further complication is that checks to their growth can result in woody or intensely fibrous layers in the root. Not very toothsome on the plate.

And they like soft, yielding soil, not too heavily manured - heavy soil, or too much manure can result in forking or hairy roots. Bendigo's climate, and stony, skeletal sedimentary soils aren't therefore particularly suited to root crop horticulture.

But with a couple of La Nina years filling the tanks and lifting the water restrictions, and a newly vacant bed with lovely soil, I thought - why not have a go at breeding up some heavy soil root crops?

Short-rooted carrots are available - but only come in one colour - orange. On the few occasions I've had success with carrots, sneeking them into a corner of the seasons, I've grown 'Baby' variety. Nice, sweet carrot, but how come there aren't purple, yellow and white short rooted carrots? I already had some purple carrot seed from a few years ago, when i had some success with '3 Colours Purple', and there was a bag of home-collected seed in the door of the beer fridge. And a couple of carrots were going to seed in the asparagus patch - leftovers from a relatively unsuccessful crop a couple of years ago that had dropped some seed and few volunteers had come up, and been ignored.

And there was a grower at the local monthly farmers' market who sold purple, white and yellow long rooted carrots - I could just buy some, replant them, and grow them out for seed.

So, the plan is to sow coloured carrots, and short rooted carrots, let them cross, and then select for short rooted coloured carrots. Easy! (not).

Carrots suffer from inbreeding depression - collecting seed from just a couple of plants doesn't give sufficient genetic diversity, and after a few generations, the quality declines. So a big population of seeding plants is required. No single best plant, individual pollination here - it's mass selection time. This is going to require a bit of growing bed space.

And there is a second complication - some varieties for sale are F1 hybrids. So you ask, how does a seed company get F1 hybrids if they need lots of outcrossing between plants to maintain vigour? they can't go around individually pollinating flowers. Carrots are Umbelifereae - they have huge complex flowerheads, with tiny individual flowers - not the place for individual cross pollination, particullarly if you need to produce masses of seed for sale.

They use a genetic trait that is very useful for them, but nasty for the individual breeder - male sterility (thanks to Joseph over at Homegrown Goodness for this info). Some lines of carrots (and other commercial crops) carry a gene for male sterility - they don't producce pollen. So to get an F1 hybrid, plant lots of male sterile seed next to another variety that produces pollen, and any seed from the male sterile plants will be hybrid - it can't have pollinated itself, since it doesn't produce pollen. Why is this bad for the ameteur breeder? Because the male sterility is confered on the offspring. So unless you want a pollen sterile line, best not to incorporate these into your germplasm.

Pity I didn't realise this before I sowed seed - but not to worry, I'll just eat those ones.
So my seed sowing is
3 Colours Purple - for purple
Chantenay - for short stumpy roots
Baby  - ditto
French Round - for golf ball shape

and my mistakes -
 Harlequin F1 multicolour (which might not be male sterile)
Purple Haze F1 purple over orange centre - which i guess is male sterile.

I've also got some heritage varieties as replacement, 'Belgian White' and 'Lobbericher'- these will probably go in this weekend.

Parsnips need their own post...

04 April 2012

A totally off the point post - Plains Wanderer sighting

At a property west of Kerang, spotted this Plains Wanderer out spotlighting on the native grasslands between the Avoca River and Back Creek

02 April 2012

Progress on the TPS

Been offsite for 5 days, and can't believe the growth the TPS have put on. Must be the mild autumn weather.

20 March 2012

TPS - True Potato Seed

True potato seed (TPS) is the seed produced from the fruits of flowering potato plants that have gone through sexual reproduction. So called 'seed potatoes' that are commercially available, are not really seeds, but tubers from a selected potato line - they are identical to the parent plant, since it is just vegetative propagation. There is virtually no chance of a different potato arising from this sort of propagation - indeed, that is just the point - commercial growers want reliability in the crop they are producing.

But TPS introduces genetic variability. And a quirk of most potatoes is their polyploidy. Most normal plants have pairs of chromosomes. But most 'modern' potatoes are tetraploid, they have double the number of chromosomes, which gives rise to all sorts of genetic mixing if they reproduce sexually through the flowering-cross polllination-setting seed route. This genetic mixing has the possibility of developing all sorts of interesting characteristics in the offspring.

It is possible to cross potatoes, using a similar method to tomatoes - emasculate the female parent by removing the anthers pefore they shed pollen, collect pollen from the male parent, then apply it to female parent stigma. Rather than go through all the mechanics of this, check out the information at Tom Wagner's tater-mater blog, or Rebsie Fairholm's excellent daughterofthesoil blog.

Alternatively, if you have a variety that flowers readily (not all do) and that has no self-compatibility problems (many do), and that retains its fruits to maturity, you can just see what turns up. That's what I've done.

My TPS, in this generation at least, is from self pollinated Pinkeye potatoes, derived from some certified seed tubers I purchased at my local nursery (sourced from Goodmans Seeds, if I remember correctly). There is a slight chance they have crossed with another self-propagated potato that just came up in my garden nearby, which also set a fruit, but it wasn't flowering at the same time as the Pinkeyes, so the chances of an intervariety cross is slim.

The fruits mature a bit like small hard green tomatoes, (sorry, the pic is a bit blurry) and the seed is fermented out like tomato seed - squeeze into a small container like an egg cup, leave open to the air for a few days until it ferments, then rinse the seed out in a tea strainer, and dry on a bit of paper towel.





Sow it like tomato seed, and prick out. That's where I am now - a bit risky at the start of autumn, since these little plants really need to set a tuber between now and winter, so I have something to plant out next spring.







This involves a bit of 'hilling up' in the pots, covering the lower leaves to induce tuberisation. Let the experiment continue.









I'm also intending on growing out some plants to do a bit of crossing next season. A greengrocer in Melbourne stocks a good range of vegetables, so I bought a couple of tubers of all their interesting non-standard lines - Pink Fir Apple, Virginia Rose, Blue Zarr, Royal Blue (which look the same), and Gold Finger.
Hopefully they will flower, and I'll get some more interesting colours to throw into the mix.
I've already got Purple Congo and another couple growing in the greenhouse, so I'll see what happens with their flowering phenology over autumn/winter.

12 March 2012

Summer seed production

I've just harvested the five F1 growouts I tried as an experiment to see if I could sneek an additional generation into the growing year, and shorten my generation turnover time.
A bunch of seed didn't germinate - I think due to soil borne disease or rot. Lucky they were my excess 'wrong way' crosses.
Of the five plants that I grew in pots, I got 26 seed for one of the crosses from 3 plants, and 19 seed from two plants for the other cross. Not  a huge haul, but useful. Powdery mildew  struck the plants over the last few weeks, and the last of the pods on the plants were fertilised, but failed to develop. I was too busy to spray with potassium bicarbonate.

These F2 seeds will get sown in the next few days, with a potential F3 crop in 3 months. The odds that my purple snowpea is going to show in the F2 is a bit low.
From my PurplePod X PurpleFloweredMammoth cross, both carry A, that turns on purple, so that's covered. But I'm also looking for purple in the pods, that needs  Pu_Pur_ (doesn't matter at this stage if they are heterozygous), and ppvv the two recessive genes for non-fiberous pods (so they need to be homozygous) so the probability is 3/4 X 3/4 X 1/4 X 1/4 = 9/256, say around 1 in 30 for any given plant, and I've got 26 seeds. Twice that number of seeds would have been useful, but the chances aren't too bad.

My PurplePodded X MeltingMammoth has less seeds and is also less likely since MM doesn't carry A. So the odds for a purple snow from any one of the F2 seeds is 9/1024, or around 1/100. With only 19 seeds my chances aren't too good in this generation.

None of these parents were powdery mildew resistant, so I will either have to cross in a subsequent generation, or hope that one of my other crosses (which I'm only growing the F1s of this autumn) carries the genes for that trait.

With a bit of luck, some of the PP X PFM F2s will also inherit the double flower gene from the PFM parent.

On a side note, the Purple Flowered Mammoth was a mis labelled plant that came up in a Melting Mammoth batch - I might have interplanted it with some seed I got from a 'net buddy (Jayendra) to fill in some gaps in the patch, but I didn't keep good records that day, so it will remain as Purple Flowered Mammoth (but I suspect it's really some of Jay's Yakumo line - but Jay's seed is a different colour to my purchased Yakumo, so I don't know what's going on. Doesn't matter, it was a nice snow pea with big pods).

21 February 2012

Summer pea F1 growouts - developing pods and some anomolies

I've just been out to have a look at my snow pea F1 growouts a bit more closely. These were wrong way crosses, recessive pollen to dominant flower, so I shouldn't be able to tell if my pollinations were successful or were crosses. 

pic 1 - lovely purple pods in the F1








pic 2 - blotchy not so purple pods in the F1

But the pods, which should be nice and purple, are only tinged with purple for one of the crosses - I wonder what is going on since the female parent "Purple Podded - Lost Seed Co"is the same in both cases.









The plants are growing in pots next to each other, so should have the same growth conditions (tho the 'not so purples' are in a smaller pot with two plants, and the 'lovely purples' are in a slightly larger pot with three plants.

But there are some other differences as well - 'not so' has less full pods, and was earlier in flowering, 'lovely' has more flowers and larger, fuller pods. Hmmm, back to the text books...

T

26 January 2012

Summer pea growouts

In an attempt to shorten the generational time span, and get results more quickly, I sowed an experimental lot of F1 seeds from spring breeding program. These were only 2 or 3 seeds from a number of 'wrong way' crosses (recessive pollen to dominant flower). My total seed haul of crosses was about 80 seeds - too many to grow out this coming season, so I thought I would experiment and see if I could get some F2 seed over summer. Accepted wisdom is that peas don't grow well in summer - especially here in Bendigo where summer temperatures commonly exceed 32C for days, or weeks, on end.






But I cunningly selected a shady spot round the south side of the house, in a recently excavated walkway, so the area is both shady and cooled by the brick house on one side, and the railway sleeper and drystone wall on the other, niether of which receives much direct sunlight.
I've been surprised by the results.
One batch is now about 1.6 metres high, and still powering on, and the other about 1.4 metres, and just commencing flowering. If they set pods, I should have some F2 seed to work on this autumn.