Potato Onions - a strange seedling

Spud onions reproduce vegetatively - plant one bulb, it divides, and produces multiple bulbs at the end of the season. They aren't supposed to flower, but Kelly Winterton got them to, and distributed seed.
One of my seedlings this year has produced a quite unusual reproductive strategy - it has divided at the base, flowered in its first year and produced seeds,  and also produced topsets!
The plant in question is just above the blades of the secateurs in this picture. note thick wrappers, and divided bulb.

 But I noticed a seedhead on the top - unusual since I didn't get this from one season old seedlings last year. A closer look revealed small topset onions forming - lower left below.

 And in the seedhead, maturing capsules, and some mature seed. Not sure how to deal with this baby...

Selection of snow peas

This spring I've grown out a couple of selections of F4 yellow snow peas. I should probably go through the development of these lines, if only to remind my self of what went on.
These were originally grown as a bit of an afterthought along a marginal dry bed next to a half shaded fence. I had returned from a lengthy winter holiday to find a mass of F1 plants with set pods, but because of weather conditions, some of the pods had sprouted or sprouting seeds in them. I just chucked a whole heap of what I thought were ruined seeds into a bed, and got a great germination. The plants struggled, many only setting one or two weak pods, so selection was a bit difficult, but two plants stood out, with big pods, and vigour.
I bulk collected the yellows, and individually bagged the good plants, and grew them out.

Contemplating new pea crosses

tMy target yellow snow pea is a dwarf, double flowered, powdery mildew-resistant, sweet, big-podded pea.
My F4 plants of Tall Yellow Snow, a cross between Golden Podded and what I think was Yakumo, are just producing their first pods. But they aren't double flowered, nor disease resistant.

But one of my purple snow pea crosses Delta Louisa X Chamber of Death produced a double flowered green podded F2 that was tall, highly disease resistant, and with huge pods. I'm growing some of F3s of this plant just to see what happens - it was such an outstanding plant last year that I had to grow it out, even tho it was never going to produce coloured pods. Of the twelve of so F3 plants I'm growing, four are dwarfs. If they produce big pods, they might be likely candidates for a cross to the Tall Yellow Snows.

This would make a good cross since the two genes for powdery mildew resistance are both recessive, and the two multi-flower genes (doesn't matter which one I get) are also recessive, as are all the dwarfing genes - again, it doesn't really matter which ones I get.

I'm also wondering which way to do the cross - the usual plan is to do a cross so that the F1 plants show if the cross was successful. For example, when crossing a tall (dominant) to a dwarf (recessive), put the tall pollen on the dwarf flower, and if the cross pollination was successful, the F1 plants will be tall since the F1s should be heterozygous for tall. If however the F1s are dwarf, this indicates that the cross was not successful, and the dwarf plant has pollinated itself in the normal way. This is useful since it saves you from growing out unsuccessful crosses for two generations, (the population starts segregating in the F2 generation).

However there is the issue of maternal cytoplasmic DNA. This resides in the mitochondria and chloroplasts, the power machinery of the cell, rather than in the nucleus, and is only passed down in the maternal line. So if you are after robustness, then using the robust plant as the mother makes sense - it might be connected with the cytoplasmic genetic material so it's a good way of hedging your bets.

So today I'll be out in the vege gardens, looking for flowers that are just at the right stage of maturity.

Another late winter update - The Coloured Pea Project selection strategies

While I was away on leave, I had Craig, a grad student of mine, come in and assess the autumn pea growout, and collect pods from any coloured peas to dry down. Returned to find lots of paper lunch bags all neatly labelled and drying in the shed, but it smelled a bit musty, so all the bags came in and were dried off for a couple of days in the oven set to 'defrost'.

Production was poor - we had a cold wet winter for Bendigo, and I think the Powdery Mildew might have shortened the lives of many plants.

But I got lots of very promising lines to explore.

Last autumn I went through my purple podded project growouts, which essentially came from three crossed lines

Delta Louisa X Purple Podded - target = a semi-dwarf semi-resistant snow
Tall Purple-flowered Mammoth X Purple Podded - target = a tall non resistant big podded snow
Chamber of Death X Purple Podded - target = a highly resistant semi-dwarf snow

I was also looking at developing a better yellow snow, by crossing Golden Podded with my Purple Flowered Mammoth.

(There were a number of other crosses - a generic sugar snap X Purple Podded, Golden Podded X Purple Podded, and a few other random crosses because I could).
The F2 grow outs from last spring yielded a number of promising lines, half purple snows, full purple big podded non-snows, disease resistant half purple dwarf snows, disease resistant tall purple non-snows, seemingly every combination of characteristics, apart from the target . So how to proceed?

I set up 5 'projects' using the F3 seed material I had harvested.

TPM - Tall Purple Mammoth, looking for a big podded purple snow, with no disease resistance
TMM - Tall Mauve Mammoth looking for a big-podded half purple snow, no disease resistance
RPC - Resistant Purple Chamber of Death - looking for a highly resistant purple snow, tall or short
RMC - Resistant Mauve Chamber of Death - looking for a highly resistant half purple snow, tall or short.
 TYS - Tall Yellow Snow - looking for a tall yellow snow, with big pods and good flavour, with no disease resistance.

I thought I could persue these lines, using selection and even if I didn't get the desired target, I could use the mauve lines to back cross or cross together if they had the desirable characteristics. Rather than plant a few of everything, I selected the most promising parents, and grew out 6 seeds from 12 of the lines in foam boxes in the shade through the middle of summer - didn't really work, with only one or two lines producing any seed. So in autumn, I resowed a lot of the F3 seed, and a couple of F4 mauves that had done OK (plant 6).

So now I have a pile of F4 seed from the autumn growouts, but most plants only produced one or two small pods. This is disappointing on a number of fronts - I didn't get to test the quality of the pods, and there isn't really enough material to do big selected F4 growouts to check on homo/heterozygosity.

Dividing the lines early into Purple and Mauve projects was a bit premature - the purple lines produced sufficient mauve material in the F3 plants to go on with, but suprisingly, some of the mauve lines produced nearly full purples. This is a suprising result since pod colour is supposed to be controlled by 3 dominant genes, but it sure looks like there are other things going on here, with the purple sometimes being expressed in the later pods on a plant, but not on the early ones, and a number of different patterns of semi purple expression.

Another problem is the sheer amount of different material that is produced. I now have thousands of seeds in four generations across dozens of lines - just cataloging and storing it all takes so much time. And then making decisions about which lines to persue in my limited garden space - whew!

On the long drive between Halls Creek and Alice Springs and points further south, I spent a couple of days working out the probability of homozygous recessive genes being expressed in say an F3 generation if the F2 parent is heterozygous. My question was "How many plants would I need to grow of say an F3 generation to tell if the F2 parent was heterozygous at one locus?"  An example might help. Say I've got a tall pea, that had tall and dwarf characteristics in its parentage. It might be homozygous tall, that is carrying TT, so it will never give dwarf offspring. But what if it is heterozygous Tt? If I grow one plant, there is a 1/4 chance of it being homozygous dwarf, or tt. If I grow two plants the chances of at least one dwarf plant showing up, and therefore indicating the parent was heterozygous, is 1/4 + 3/16 = .4375. Three plants gives 37/64, or .578. I had forgotten my binomial distributions, so basically went back to first principles to figure it out.  I seem to recall that I came up with 6 plants to be around 82% sure, which doesn't meet the requirements of an ecology experiment, say, but will do me in my garden.

So how does this help me? If I want to find a purple snow, I can grow out 6 from a purple non-snow parent to see if one of the low fibre recessive genes is lurking there. This will let me know with about 80% confidence, whether the line is worth continuing on with or not. If it has no snow pea genes in it, then I can save time and space by rejecting those lines that are unlikely to produce what I want.

So I'm going with a combination of selection and mass grow out - growing 6 or so plants from all the purple lines, all of the seeds in the lines where purple is apparent but snow is also present, and a few 'hedge my bets' lines, that might prove to be promising parents for some characteristics if the purple growouts are not too succesful and I need to cross back to something for desirable characteristics. Pity that such a cross would need another couple of generations to roduce results, but hey, that's plant breeding!
No pics at the moment, but more to follow

Coloured snow pea progress

An update on the progress in the F2 grow outs.
I did my initial crosses in November 2011, crossing all sorts of peas with others.

The main focus was a search for a purple snow pea - crossing 3 different lines of purple podded peas with 5 different lines of snows and snaps including dwarf varieties and those with supposed powdery mildew resistance.

I also crossed a yellow podded variety with a purple podded, looking for a red podded pea to use as a progenitor for a red snow line. Although the  yellow is supposed to be a snow pea, it has few redeeming features apart from its pale pods, and so seemed unlikely to be able to produce a tasty yellow full snow pea. To get something worthwhile, I figured I would have to cross any red podded back to a decent snow pea.

I grew out some of the F1 seeds last summer, planting into pots, and growing them on the shady side of the house. Only one line produced any seed. I'll report on that in another post.

Most of the F1 seed was sown in February 2012, for an autumn growout. Most lines succeeded, showing real hybrid vigour. Unfortunately some set seed while I was away on holiday, and proceeded to germinate in the pod following some rainy weather in July. I returned to harvest the seed only to find that much of it was spoiled. I threw the germinated seed - even tho it was shriveled up - into some seed trays, and was rewarded with a few dozen F2 plants that I then planted in a tight little bed on the boundary fence between my backyard and the playground next door.This was the yellowX purple podded cross, not my main focus. But this line has just started to produce pods, and I've got a nice half red plant, and this morning I noticed a fully red pod on one plant. As a bonus, one of the plants has produced what appears to be a nice big yellow snow - not at all what I was expecting from this line.

The second line that pod-germinated was the yellowXsnow cross. Again, I chucked the seed into a tray, not expecting much, and planted the resulting F2s into another fence bed beside the hothouse. This seems to have produced at least one attractive looking big yellow snow.

Looking forward to the next few weeks as the rest of the plants come on stream.

And I've also got huge amounts of seed from multiple lines to explore next autumn, if I can find room.